Patent Application
20240162138
The present disclosure belongs to the technical field of electronic elements, and in particular to a method for forming a conductive via, a conductive via and a passive device.
With the development of the electronic information industry, various electronic components are developing towards miniaturization and low power consumption, and have a higher and higher integration level. For memory chips, high-brightness LEDs, high-quality-factor (Q-factor) inductor devices in radio frequency circuits and integrated passive devices, etc., the single-sided integration density has been high, and there is no additional area for providing devices. In order to further improve the integration level, a structure is required to be manufactured in three dimensions in which layers are stacked together and electrically connected with each other. Vias and blind vias with electrical communication function are necessary.
The invention intends to solve at least one of technical problems in the prior art and provides a method for forming a conductive via, a conductive via and a passive device.
In a first aspect, an embodiment of the present disclosure provides a method for forming a conductive via, including steps of:
The step of preparing a dielectric layer, and forming a connection via, which extends through the dielectric layer in a thickness direction of the dielectric layer, on the dielectric layer includes:
A material of a drill bit for the mechanical drilling process includes any one of a tungsten carbide, a tungsten-cobalt alloy, a tungsten-titanium-cobalt alloy, a natural diamond, and an artificial diamond.
The step of preparing a dielectric layer, and forming a connection via, which extends through the dielectric layer in a thickness direction of the dielectric layer, on the dielectric layer includes:
The step of forming the connection via, which extends through the dielectric layer in the thickness direction of the dielectric layer, through a sand-blasting drilling process on the dielectric layer includes:
The solid abrasive particles include at least one of carborundum, corundum, calcium carbonate, and quartz sand.
The step of preparing a dielectric layer, and forming a connection via, which extends through the dielectric layer in a thickness direction of the dielectric layer, on the dielectric layer includes:
The step of forming the connection via, which extends through the dielectric layer in the thickness direction of the dielectric layer, through a laser drilling process on the dielectric layer includes:
The laser device is a continuous laser device or a pulse laser device.
The step of preparing a dielectric layer, and forming a connection via, which extends through the dielectric layer in a thickness direction of the dielectric layer, on the dielectric layer includes:
The step of forming the connection via, which extends through the dielectric layer in the thickness direction of the dielectric layer, through a patterning process includes:
The step of forming a connection electrode in the connection via, forming a first extraction electrode on the first surface, and forming a second extraction electrode on the second surface includes steps of:
The step of forming metal films on the first surface and the second surface of the dielectric layer as seed layers includes:
The step of forming a connection electrode in the connection via, forming a first extraction electrode on the first surface, and forming a second extraction electrode on the second surface includes:
The step of forming a connection electrode in the connection via, forming a first extraction electrode on the first surface, and forming a second extraction electrode on the second surface includes:
The conductive paste includes a low-temperature curing type polymer conductive paste.
The step of coating the conductive paste includes coating the conductive paste by means of any one of screen printing, ink-jet printing, and slit coating.
Before the step of forming a connection electrode in the connection via, forming a first extraction electrode on the first surface, and forming a second extraction electrode on the second surface, the method further includes:
The step of cleaning the dielectric layer with the connection via includes:
The step of cleaning the dielectric layer with the connection via includes:
The connection via has a shape including a cylinder or an inverted truncated cone.
In a second aspect, an embodiment of the present disclosure provides a conductive via, including:
The connection via has a shape including a cylinder or an inverted truncated cone.
In a third aspect, an embodiment of the present disclosure provides a passive device, including the above conductive via.
The passive device includes at least an inductor; and
The passive device further includes a capacitor and a resistor both on the second surface.
The dielectric layer includes at least one of glass, polyimide, polyethylene terephthalate, and cyclic olefin polymer.
In order to enable one of ordinary skill in the art to better understand the technical solutions of the present disclosure, the present invention will be described in further detail with reference to the accompanying drawings and the detailed description.
Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which the present disclosure belongs. The terms “first”, “second”, and the like used in the present disclosure are not intended to indicate any order, quantity, or importance, but rather are used for distinguishing one element from another. Further, the term “a”, “an”, “the”, or the like used herein does not denote a limitation of quantity, but rather denotes the presence of at least one element. The term of “comprising”, “including”, or the like, means that the element or item preceding the term contains the element or item listed after the term and its equivalent, but does not exclude other elements or items. The term “connected”, “coupled”, or the like is not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect connections. The terms “upper”, “lower”, “left”, “right”, and the like are used only for indicating relative positional relationships, and when the absolute position of an object being described is changed, the relative positional relationships may also be changed accordingly.
In a first aspect, an embodiment of the present disclosure provides a method for forming a conductive via. A dielectric layer selected in the method includes, but is not limited to, a glass-based substrate, a silicon-based (Si-based) substrate, an SOI, a gallium arsenide (GaAs) substrate, SiC, InP, a PCB, Al2O3, or the like. The method may include steps S01 and S02.
In step S01, a dielectric layer is prepared and a connection via extending through the dielectric layer in a thickness direction of the dielectric layer is formed. The dielectric layer includes a first surface and a second surface oppositely disposed in the thickness direction thereof.
In some examples, a manner in which the connection via is formed in the dielectric layer may vary depending on a material selected for the dielectric layer. For example, the connection via extending through the dielectric layer is formed by adopting any one of mechanical drilling, sand-blasting drilling, laser drilling, patterning process and the like.
In some examples, after the step S01, the method further includes a step of cleaning the dielectric layer, such that a surface of an inner wall of the formed connection via is flat and smooth.
For example, the dielectric layer is placed into a water tank containing pure deionized water or a combination of the deionized water with a proper amount of cleaning agent (such as an oil-based cleaning agent or a water-based cleaning agent); the water is subjected to cavitation, acceleration and direct flow actions by means of ultrasonic waves, so that a pollutant layer is dispersed, emulsified and stripped to achieve the purpose of cleaning; and finally, the dielectric layer is washed by the pure deionized water and is taken out of the water tank and is dried by an air knife.
Alternatively, the dielectric layer is placed in the water tank, is firstly subjected to ultrasonic cleaning to remove floating dust on a surface of the dielectric layer; the dielectric layer is then immersed in a solution containing hydrofluoric acid for chemical corrosion, so that defects, such as microcrack areas, stress concentration areas and the like, which are near the connection via and in the inner wall of the connection via in the dielectric layer, may be thoroughly removed through the chemical corrosion; finally, the dielectric layer is washed by the pure deionized water and is taken out of the water tank and is dried by an air knife.
In S02, a connection electrode is formed in the connection via, and a first extraction electrode and a second extraction electrode are formed on the first surface and the second surface of the dielectric layer, respectively. The connection electrode at least covers the inner wall of the connection via, and the first extraction electrode and the second extraction electrode are electrically connected to the connection electrode.
In some examples, the step of forming the connection electrode, the first extraction electrode, and the second extraction electrode on the dielectric layer may include: depositing metal films on the first surface and the second surface of the dielectric layer provided with the connection via as seed layers; then, thickening the metal films through an electroplating process, so that the metal films cover the inner wall of the connection via, and even fill the connection via; patterning the metal films formed on the first surface and the second surface of the dielectric layer, for forming the first extraction electrode and the second extraction electrode.
In some examples, the step of forming the connection electrode, the first extraction electrode, and the second extraction electrode on the dielectric layer may further include: forming a chemical plating medium on the first surface and the second surface of the dielectric layer provided with the connection via, and performing a chemical plating process to form metal films, so that the metal films cover the inner wall of the connection via; patterning the metal films formed on the first surface and the second surface of the dielectric layer, for forming the first extraction electrode and the second extraction electrode.
In some examples, the step of forming the connection electrode, the first extraction electrode, and the second extraction electrode on the dielectric layer may further include: applying (extruding) a metal paste into the connection via of the dielectric layer, and forming the metal paste on the first surface and the second surface of the dielectric layer; and then, curing the metal paste on the first surface and the second surface, respectively, to form the connection electrode filled in the connection via, the first extraction electrode on the first surface and the second extraction electrode on the second surface.
In order to clarify the method for forming the conductive via according to the embodiment of the present disclosure, the formation method is specifically described below according to materials of the dielectric layer. The following examples should not be construed as limiting the scope of the embodiments of the present disclosure.
S11, preparing a dielectric layer 11, wherein a material of the dielectric layer 11 includes, but is not limited to, any one of glass, Si, SOI, GaAs, SiC, InP, PCB, Al2O3; forming a connection via 11a through a mechanical drilling process on the dielectric layer 11.
In some examples, a material of a drill bit used for the mechanical drilling process is a material with a high rigidity, such as a tungsten carbide, a tungsten-cobalt alloy, a tungsten-titanium-cobalt alloy, or any other alloy with a high rigidity (an HRC value greater than 90 degrees), or a natural diamond, an artificial diamond, or the like. A thickness of the dielectric layer 11 is in a range of 0.1 mm to 2 mm, and a diameter of the connection via 11a is in a range of 0.5 mm to 1.5 mm. According to shapes of different drill bits and drilling conditions (rotating speed, drilling speed and the like), the inner wall of the connection via 11a may be kept straight or tapered from top to bottom, and an inclination angle of the connection via 11a is approximately in a range of 0° to 15°. For example, the inclination angle of the connection via 11a is 15°.
It should be noted that in the embodiment of the present disclosure, the top and the bottom of the inner wall of the connection via 11a are described as relative to each other. In
S12, cleaning the dielectric layer 11 after step S11, so that residues, debris (11b shown in
In some examples, step S12 may specifically include: placing the dielectric layer 11 into a water tank containing pure deionized water or a combination of the deionized water with a proper amount of cleaning agent (such as an oil-based cleaning agent or a water-based cleaning agent) at a temperature approximately in a range of 35° C. to 70° C., wherein the water is subjected to cavitation, acceleration and direct flow actions by means of ultrasonic waves (with a frequency approximately in a range of 10 kHz to 10 MHz), so that a pollutant layer is dispersed, emulsified and stripped to achieve the purpose of cleaning, wherein the cleaning time is approximately in a range of 2 to 20 minutes; and finally, washing the dielectric layer 11 by using the pure deionized water, and taking the dielectric layer 11 out of the water tank, and drying the dielectric layer 11 by using an air knife.
S13, forming metal films 120, as seed layers, within the connection via 11a in the dielectric layer 11, and on the first surface and the second surface of the dielectric layer 11, after the step S12.
In some examples, step S13 may specifically include: depositing metal films 120 with good conductivity, as seed layers, on the whole first surface and the whole second surface of the dielectric layer 11 through a process including, but being not limited to, a magnetron sputtering process. In addition to the magnetron sputtering process, the metal films 120 may be formed through an electron beam evaporation process, a thermal evaporation process, or a pulsed laser sputtering process.
In some examples, a metal stack is generally used as the metal film to increase the adhesion between the metal film and the dielectric layer 11. That is, the metal film may include a first metal sub-layer and a second metal sub-layer sequentially arranged in a direction away from the dielectric layer 11. A material of the first metal sub-layer includes, but is not limited to, any one of titanium (Ti), molybdenum (Mo), and nickel (Ni), and a material of the second metal sub-layer includes, but is not limited to, any one of copper (Cu), silver (Ag), or gold (Au). For example, the metal film may include: any one of Ti/Cu, Mo/Cu, Ni/Cu, Ti/Ag, Mo/Ag and Ni/Ag. In the embodiment of the present disclosure, a thickness of the first metal sub-layer is in a range of about 1 nm to about 100 nm; a thickness of the second metal sub-layer is in a range of about 50 nm to about 1000 nm. In addition, a thickness of the metal film on the inner wall of the connection via 11a is in a range of about 1 nm to about 200 nm.
S14, filling the connection via 11a through an electroplating process and thickening the metal films 120 formed on the first surface and the second surface, after the step S13, to form a first extraction electrode 1201 on the first surface and a second extraction electrode 1202 on the second surface, respectively, and a connection electrode 1203 within the connection via 11a.
In some examples, step S14 may specifically include: firstly, a via-filling electroplating process is performed in an electroplating bath through a reasonable combination of different types of electroplating solutions (such as a formula for filling the metal film into the connection via 11a and a formula for thickening the metal films on the whole surfaces), so that the metal film 120 (such as a first metal sub-layer in the metal film 120) is deposited on the inner wall of the connection via 11a, wherein an electroplating rate is in a range of 0.5 um/min to 5 um/min, and depending to an electroplating duration, the metal material may fully fill the connection via 11a (a thickness of the metal film is equal to 0.5 times of a diameter of the connection via 11a) or not fully fill the connection via 11a, only the inner wall of the connection via 11a is metallized (the thickness of the metal film is in a range of 500 nm to 10 um). That is, the connection electrode 1203 is formed. Then, the dielectric layer 11 is moved into the electroplating bath for the formula for thickening the metal films on the whole surfaces, to thicken the metal films 120 on the first surface and the second surface through an electroplating process, respectively, wherein the electroplating metal is Cu, Ag or Au, the electroplating rate is in a range of 0.5 um/min to 5 um/min, and depending to the electroplating duration, a thickness of each of the thickened metal films 120a is approximately in a range of 500 nm to 500 um. After the electroplating process, the surfaces of the dielectric layer 11 are generally undulated and uneven, which adversely affects subsequent processes. Thus, finally, a chemical mechanical polishing process is performed, such that the surfaces of the dielectric layer 11 become flat and smooth, thereby forming the first extraction electrode 1201 and the second extraction electrode 1202.
Alternatively, after the electroplating process, the thickened metal films 120a on the first surface and the second surface may be patterned, to form the first extraction electrode 1201 and the second extraction electrode 1202.
S21, preparing a dielectric layer 21, wherein a material of the dielectric layer 21 includes, but is not limited to, any one of glass, Si, SOI; forming a connection via 21a through a mechanical drilling process on the dielectric layer 21.
In some examples, a material of a drill bit used for the mechanical drilling process is a material with a high rigidity, such as a tungsten carbide, a tungsten-cobalt alloy, a tungsten-titanium-cobalt alloy, or other alloys with a high rigidity (an HRC value greater than 90 degrees), or a natural diamond, an artificial diamond, or the like. A thickness of the dielectric layer 21 is in a range of 0.1 mm to 2 mm, and a diameter of the connection via 21a is in a range of 0.5 mm to 1.5 mm. According to shapes of different drill bits and drilling conditions (rotating speed, drilling speed and the like), the inner wall of the connection via 21a may be kept straight or tapered from top to bottom, and an inclination angle of the connection via 11a is approximately in a range of 0° to 15°. For example, the inclination angle of the connection via 11a is 15°.
S22, cleaning the dielectric layer 21, after step S21, so that residues, debris (21b shown in
In some examples, step S22 may specifically include: the dielectric layer 21 is placed into a water tank, wherein the dielectric layer 21 is firstly subjected to ultrasonic cleaning to remove floating dust on a surface of the dielectric layer; the dielectric layer 21 is then immersed in a solution containing hydrofluoric acid for chemical corrosion, so that defects, such as microcrack areas Q1, stress concentration areas Q2 and the like, which are near the connection via and in its inner wall on the dielectric layer 21 made of glass, Si or SOI, may be thoroughly removed through the chemical corrosion. A content of HF in the solution is approximately in a range of 1% to 20%, and NH4F may or may not be contained in the solution. When NH4F is contained, a content of NH4F is approximately in a range of 10 to 40%, a temperature of the solution is approximately in a range of 35° C. to 60° C., a duration for the chemical corrosion is approximately in a range of 30 seconds to 5 minutes. Then, the dielectric layer 21 is thoroughly washed by the pure deionized water, and finally, is dried by the air knife. The chemically corroded connection via 21a has smooth inner wall and surface and does not contain the defects, such as microcrack areas Q1, stress concentration areas Q2 and the like, which is beneficial to the growth of seed layers with a high quality, the via-filling and the thickening with metal.
S23, forming metal films 220, as seed layers, within the connection via 21a of the dielectric layer 21, and on the first surface and the second surface of the dielectric layer 21, after the step S22.
In some examples, step S23 may specifically include: depositing metal films 220 with good conductivity, as seed layers, on the whole first surface and the whole second surface of the dielectric layer 21 through a process including, but being not limited to, a magnetron sputtering process. In addition to the magnetron sputtering process, the metal films 220 may be formed through an electron beam evaporation process, an thermal evaporation process, or a pulsed laser sputtering process.
In some examples, a metal stack is generally used as the metal film 220 to increase the adhesion between the metal films 220 and the dielectric layer 21. That is, the metal films 220 include a first metal sub-layer and a second metal sub-layer sequentially arranged in a direction away from the dielectric layer. A material of the first metal sub-layer includes, but is not limited to, any one of titanium (Ti), molybdenum (Mo), and nickel (Ni), and a material of the second metal sub-layer includes, but is not limited to, any one of copper (Cu), silver (Ag), or gold (Au). For example, the metal film 220 include: any one of Ti/Cu, Mo/Cu, Ni/Cu, Ti/Ag, Mo/Ag and Ni/Ag. In the embodiment of the present disclosure, a thickness of the first metal sub-layer is in a range of about 1 nm to about 100 nm; a thickness of the second metal sub-layer is in a range of about 50 nm to about 1000 nm. In addition, a thickness of the metal film on the inner wall of the connection via 21a is in a range of about 1 nm to about 200 nm.
S24, filling the connection via 21a through an electroplating process and thickening the metal films 220 formed on the first surface and the second surface, after the step S23, to form a first extraction electrode 2201 on the first surface and a second extraction electrode 2202 on the second surface, respectively, and a connection electrode 2203 within the connection via 21a.
In some examples, step S24 may specifically include: firstly, a via-filling electroplating process is performed in an electroplating bath through a reasonable combination of different types of electroplating solutions (such as a formula for filling the metal film 220 into the connection via 21a and a formula for thickening the metal films on the whole surfaces), so that the metal film (such as a first metal sub-layer in the metal film) is deposited on the inner wall of the connection via 21a, wherein an electroplating rate is in a range of 0.5 um/min to 5 um/min, and depending to an electroplating duration, the metal material may fully fill the connection via (a thickness of the metal film is equal to 0.5 times of a diameter of the connection via) or not fully fill the connection via, only the inner wall of the connection via is metallized (the thickness of the metal film is in a range of 500 nm to 10 um). Then, the dielectric layer 21 is moved into the electroplating bath for the formula for thickening the metal films on the whole surfaces, to thicken the metal films 220 on the first surface and the second surface through an electroplating process, respectively, wherein the electroplating metal is Cu, Ag or Au, the electroplating rate is in a range of 0.5 um/min to 5 um/min, and depending to the electroplating duration, a thickness of each of the thickened metal films 220a is approximately in a range of 500 nm to 500 um. After the electroplating process, the surfaces of the dielectric layer 21 are generally undulated and uneven, which adversely affects subsequent processes. Thus, finally, a chemical mechanical polishing process is performed, such that the surfaces of the dielectric layer 21 become flat and smooth.
Alternatively, after the electroplating process, the thickened metal films 220a on the first surface and the second surface may be patterned, to form the first extraction electrode 2201 and the second extraction electrode 2202.
S31, preparing a dielectric layer 31, wherein a material of the dielectric layer 31 includes, but is not limited to, any one of glass, Si, SOI, GaAs, SiC, InP, PCB, Al2O3; forming a connection via 31a through a mechanical drilling process on the dielectric layer 31.
In some examples, a material of a drill bit used for the mechanical drilling process is a material with a high rigidity, such as a tungsten carbide, a tungsten-cobalt alloy, a tungsten-titanium-cobalt alloy, or other alloys with a high rigidity (an HRC value greater than 90 degrees), or a natural diamond, an artificial diamond, or the like. A thickness of the dielectric layer 31 is in a range of 0.1 mm to 2 mm, and a diameter of the connection via 31a is in a range of 0.5 mm to 1.5 mm. According to shapes of different drill bits and drilling conditions (rotating speed, drilling speed and the like), the inner wall of the connection via 31a may be kept straight or tapered from top to bottom, and an inclination angle of the connection via 31a is approximately in a range of 0° to 15°. For example, the inclination angle of the connection via 31a is 15°.
S32, cleaning the dielectric layer 31, after step S31, so that residues, debris (31b shown in
In some examples, step S32 may specifically include: placing the dielectric layer 31 into a water tank containing pure deionized water or a combination of the deionized water with a proper amount of cleaning agent (such as an oil-based cleaning agent or a water-based cleaning agent) at a temperature approximately in a range of 35° C. to 70° C., wherein the water is subjected to cavitation, acceleration and direct flow actions by means of ultrasonic waves (with a frequency approximately in a range of 10 kHz to 10 MHz), so that a pollutant layer is dispersed, emulsified and stripped to achieve the purpose of cleaning, wherein the cleaning time is approximately in a range of 2 to 20 minutes; and finally, washing the dielectric layer 31 by using the pure deionized water, and taking the dielectric layer 31 out of the water tank, and drying the dielectric layer 31 by using an air knife.
S33, after the step S32, applying a metal paste into the connection via 31a of the dielectric layer 31, and forming the metal paste 320 on the first surface and the second surface of the dielectric layer 31; and then, curing the metal paste 320 on the first surface and the second surface, respectively, to form a connection electrode 3203 filled in the connection via 31a, a first extraction electrode 3201 on the first surface and a second extraction electrode 3202 on the second surface.
In some examples, the metal paste 320 may be a conductive paste. A material of the conductive paste includes, but is not limited to, a low-temperature curing type polymer conductive paste, and main components of the conductive paste include conductive particles, a resin, a curing agent, a dispersant, a diluent, an adhesion enhancer, and an anti-settling agent. The conductive particles may be selected from Cu, Ag and Au, and a size of each particle is approximately in a range of 1 nm to 100 um. The resin may be bisphenol epoxy resin. The curing agent may be acid anhydrides. The dispersant may be methylimidazole. The diluent may be butyl acetate. The adhesion enhancer may be tetraethyl titanate. The anti-settling agent may be polyamides.
Step S33 may specifically include: firstly, coating the conductive paste in the connection via 31a and around an edge of the connection via 31a on the second surface, and then, performing solvent drying and thermocuring processes on the second surface of the dielectric layer 31 to form the connection electrode 3203 filled in the connection via 31a and the second extraction electrode 3202 located on the second surface; then, coating the conductive paste around an edge of the connection via 31a on the first surface of the dielectric layer 31, and then, performing solvent drying and thermocuring processes on the first surface of the dielectric layer 31 to form the first extraction electrode 3201 located on the first surface. The preferred mode for coating the conductive paste includes, but is not limited to, screen printing, ink-jet printing, slit coating or the like. A vacuum adsorption machine is used in cooperation when the conductive paste is coated, so that the coating efficiency may be improved, and a distribution profile of the conductive paste on the wall and the edge of the connection via may be improved. The solvent drying process may be performed under an atmospheric pressure of air, an atmospheric pressure of N2 or the vacuum, at a temperature in a range of about 40° C. to about 95° C., for a duration in a range of about 1 min to about 30 min. The thermocuring process may be performed in an oven, under the atmosphere of N2, at a heating temperature in a range of about 140° C. to about 200° C. Alternatively, the curing process may be performed by means of illumination with laser beams, which have a wavelength in a range of about 500 nm to about 1510 nm, a laser power in a range of 50 mW to 50 W, and a beam diameter in a range of about 10 um to about 2000 um, and the laser beams may be a single beam or multiple beams.
S41, preparing a dielectric layer 41, wherein a material of the dielectric layer 41 includes, but is not limited to, any one of glass, Si, SOI; forming a connection via 41a through a mechanical drilling process on the dielectric layer 41.
In some examples, a material of a drill bit used for the mechanical drilling process is a material with a high rigidity, such as a tungsten carbide, a tungsten-cobalt alloy, a tungsten-titanium-cobalt alloy, or other alloys with a high rigidity (an HRC value greater than 90 degrees), or a natural diamond, an artificial diamond, or the like. A thickness of the dielectric layer 41 is in a range of 0.1 mm to 2 mm, and a diameter of the connection via 41a is in a range of 0.5 mm to 1.5 mm. According to shapes of different drill bits and drilling conditions (rotating speed, drilling speed and the like), the inner wall of the connection via 41a may be kept straight or tapered from top to bottom, and an inclination angle of the connection via 41a is approximately in a range of 0° to 15°. For example, the inclination angle of the connection via 41a is 15°.
S42, cleaning the dielectric layer 41, after step S41, so that residues, debris (41b shown in
In some examples, step S42 may specifically include: the dielectric layer 41 is placed into a water tank, wherein the dielectric layer 41 is firstly subjected to ultrasonic cleaning to remove floating dust on a surface of the dielectric layer; the dielectric layer 41 is then immersed in a solution containing hydrofluoric acid for chemical corrosion, so that defects, such as microcrack areas Q1, stress concentration areas Q2 and the like, which are near the connection via 41a and in its inner wall on the dielectric layer 41 made of glass, Si or SOL, may be thoroughly removed through the chemical corrosion. A content of HF in the solution is approximately in a range of 1% to 20%, and NH4F may or may not be contained in the solution. When NH4F is contained, a content of NH4F is approximately in a range of 10 to 40%, a temperature of the solution is approximately in a range of 35° C. to 60° C., a duration for the chemical corrosion is approximately in a range of 30 seconds to 5 minutes. Then, the dielectric layer 41 is thoroughly washed by the pure deionized water, and finally, is dried by the air knife. The chemically corroded connection via 41a has smooth inner wall and surface and does not contain the defects, such as microcrack areas Q1, stress concentration areas Q2 and the like.
S43, after the step S42, applying a metal paste 420 into the connection via 41a of the dielectric layer 41, and forming the metal paste 420 on the first surface and the second surface of the dielectric layer 41; and then, curing the metal paste 420 on the first surface and the second surface, respectively, to form a connection electrode 4203 filled in the connection via 41a, a first extraction electrode 4201 on the first surface and a second extraction electrode 4202 on the second surface.
In some examples, the metal paste 420 may be a conductive paste. A material of the conductive paste includes, but is not limited to, a low-temperature curing type polymer conductive paste, and main components of the conductive paste include conductive particles, a resin, a curing agent, a dispersant, a diluent, an adhesion enhancer, and an anti-settling agent. The conductive particles may be selected from Cu, Ag and Au, and a size of each particle is approximately in a range of 1 nm to 100 um. The resin may be bisphenol epoxy resin. The curing agent may be acid anhydrides. The dispersant may be methylimidazole. The diluent may be butyl acetate. The adhesion enhancer may be tetraethyl titanate. The anti-settling agent may be polyamides.
Step S43 may specifically include: firstly, coating the conductive paste in the connection via 41a and around an edge of the connection via 41a on the second surface, and then, performing solvent drying and thermocuring processes on the second surface of the dielectric layer 41 to form the connection electrode 4203 filled in the connection via 41a and the second extraction electrode 4202 located on the second surface; then, coating the conductive paste around an edge of the connection via 41a on the first surface of the dielectric layer 41, and then, performing solvent drying and thermocuring processes on the first surface of the dielectric layer 41 to form the first extraction electrode 4201 located on the first surface. The preferred mode for coating the conductive paste includes, but is not limited to, screen printing, ink-jet printing, slit coating or the like. A vacuum adsorption machine is used in cooperation when the conductive paste is coated, so that the coating efficiency may be improved, and a distribution profile of the conductive paste on the wall and the edge of the via may be improved. The solvent drying process may be performed under an atmospheric pressure of air, an atmospheric pressure of N2 or the vacuum, at a temperature in a range of about 40° C. to about 95° C., for a duration in a range of about 1 min to about 30 min. The thermocuring process may be performed in an oven, under the atmosphere of N2, at a heating temperature in a range of about 140° C. to about 200° C. Alternatively, the curing process may be performed by means of illumination with laser beams, which have a wavelength in a range of about 500 nm to about 1510 nm, a laser power in a range of 50 mW to 50 W, and a beam diameter in a range of about 10 um to about 2000 um, and the laser beams may be a single beam or multiple beams.
S51, preparing a dielectric layer 51, wherein a material of the dielectric layer 51 includes, but is not limited to, any one of glass, Si, SOI, GaAs, SiC, InP, PCB, Al2O3; forming a connection via Sla through a mechanical drilling process on the dielectric layer 51.
In some examples, a material of a drill bit used for the mechanical drilling process is a material with a high rigidity, such as a tungsten carbide, a tungsten-cobalt alloy, a tungsten-titanium-cobalt alloy, or other alloys with a high rigidity (an HRC value greater than 90 degrees), or a natural diamond, an artificial diamond, or the like. A thickness of the dielectric layer 51 is in a range of 0.1 mm to 2 mm, and a diameter of the connection via Sla is in a range of 0.5 mm to 1.5 mm. According to shapes of different drill bits and drilling conditions (rotating speed, drilling speed and the like), the inner wall of the connection via Sla may be kept straight or tapered from top to bottom, and an inclination angle of the connection via Sla is approximately in a range of 0° to 15°. For example, the inclination angle of the connection via Sla is 15°.
S52, cleaning the dielectric layer 51, after step S51, so that residues, debris (51b shown in
In some examples, step S52 may specifically include: placing the dielectric layer 51 into a water tank containing pure deionized water or a combination of the deionized water with a proper amount of cleaning agent (such as an oil-based cleaning agent or a water-based cleaning agent) at a temperature approximately in a range of 35° C. to 70° C., wherein the water is subjected to cavitation, acceleration and direct flow actions by means of ultrasonic waves (with a frequency approximately in a range of 10 kHz to 10 MHz), so that a pollutant layer is dispersed, emulsified and stripped to achieve the purpose of cleaning, wherein the cleaning time is approximately in a range of 2 to 20 minutes; and finally, washing the dielectric layer 51 by using the pure deionized water, and taking the dielectric layer 51 out of the water tank, and drying the dielectric layer 51 by using an air knife.
S53, forming a chemical plating medium 520 on the first surface and the second surface of the dielectric layer 51 provided with the connection via 51a after the step S52.
In some examples, step S53 may specifically include: placing the dielectric layer 51, in a spraying mode or directly, into a water tank containing a solution of the chemical plating medium 520, so that a layer of Sn2+ is adsorbed on surfaces of the dielectric layer 51. The solution of the chemical plating medium 520 mainly contains SnCl2 of 10 g/L to 30 g/L, concentrated hydrochloric acid (having a concentration of 38%) of 20 ml/L to 60 ml/L and deionized water. A less number of Sn particles are added into the solution to prevent the Sn2+ from being oxidated. Then, the dielectric layer 51 is placed, in a spraying mode or directly, into a water tank containing an activation solution, so that surfaces of the dielectric layer 51 reacts with the activation solution (mainly containing SnCl2 of 80 g/L to 120 g/L, concentrated hydrochloric acid of 300 ml/L to 500 ml/L, Na2SnO3 of 10 g/L to 20 g/L, PdCl2 of 1 g/L to 4 g/L and deionized water), to generate metal palladium particles which are tightly attached to the surfaces of the dielectric layer 51. That is, the chemical plating medium 520 is formed on the first surface and the second surface of the dielectric layer 51 provided with the connection via Sla. It should be noted that the chemical plating medium 520 may be formed on the first surface, and then, on the second surface of the dielectric layer 51.
S54, after the step S53, performing a chemical plating process on the dielectric layer 51 with the chemical plating medium 520 to form metal films on the first surface, the second surface of the dielectric layer 51, and in the connection via 51a, and patterning the metal films formed on the first surface and the second surface of the dielectric layer 51, for forming a first extraction electrode 5201 and a second extraction electrode 5202, and a connection electrode 5203 in the connection via 51a.
In some examples, the chemically plated metal films may be a single-layer metal film or may be metal films stacked together. For example: only a Cu metal film is plated to form a single-layer metal film (having a thickness in a range of about 1 um to about 100 um). Alternatively, it is also possible to firstly plate a Ni metal film (having a thickness in a range of about 10 um to about 100 um), and then a Cu metal film (having a thickness in a range of about 1 um to about 100 um), wherein the Ni metal film is used to increase the adhesion of the Cu metal film. In the embodiment of the present disclosure, as an example, a material of the single-layer metal film is Cu, and a material of metal films stacked together is Ni/Cu, which does not limit the scope of the embodiment of the present disclosure. It will be described below by taking an example in which Ni/Cu metal films are chemically plated.
In some examples, step S54 may specifically include: placing the dielectric layer 51 into the chemical plating solution, and sequentially performing the chemical plating process with metal Ni and Cu. Then, the metal films formed on the first surface and the second surface of the dielectric layer 51 are patterned, for forming the first extraction electrode 5201 and the second extraction electrode 5202, and the connection electrode 5203 in the connection via Sla. The Ni solution for the chemical plating generally contains NiSO4·6H2O of 10 g/L to 30 g/L, NaH2PO4·2H2O 20 g/L to 40 g/L, Na-Citrate of 5 g/L to 15 g/L and NH4Cl of 20 g/L to 40 g/L, the solution is alkaline, has a PH in a range of 8.0 to 10.0 and a temperature in a range of 75° C. to 90° C. The Cu solution for the chemical plating generally contains KNaC4H4O6 of 30 g/L to 50 g/L, NaOH of 8 g/L to 10 g/L, Na2CO3 of 38 g/L to 40 g/L, CuSO4 of 10 g/L to 20 g/L, NiCl2 of 2 g/L to 6 g/L and formaldehyde of 40 ml/L to 60 ml/L with a concentration of 35%, the solution is alkaline, has a PH in a range of 11.0 to 14.0 and a temperature in a range of 55° C. to 65° C.
S61, preparing a dielectric layer 61, wherein a material of the dielectric layer 61 includes, but is not limited to, any one of glass, Si, SOI, GaAs, SiC, InP, PCB, Al2O3; forming a connection via 61a through a mechanical drilling process on the dielectric layer 61.
In some examples, a material of a drill bit used for the mechanical drilling process is a material with a high rigidity, such as a tungsten carbide, a tungsten-cobalt alloy, a tungsten-titanium-cobalt alloy, or other alloys with a high rigidity (an HRC value greater than 90 degrees), or a natural diamond, an artificial diamond, or the like. A thickness of the dielectric layer 61 is in a range of 0.1 mm to 2 mm, and a diameter of the connection via 61a is in a range of 0.5 mm to 1.5 mm. According to shapes of different drill bits and drilling conditions (rotating speed, drilling speed and the like), the inner wall of the connection via 61a may be kept straight or tapered from top to bottom, and an inclination angle of the connection via 61a is approximately in a range of 0° to 15°. For example, the inclination angle of the connection via 61a is 15°.
S62, cleaning the dielectric layer 61, after step S61, so that residues, debris (61b shown in
In some examples, step S62 may specifically include: the dielectric layer 61 is placed into a water tank, wherein the dielectric layer 61 is firstly subjected to ultrasonic cleaning to remove floating dust on a surface of the dielectric layer; the dielectric layer 61 is then immersed in a solution containing hydrofluoric acid for chemical corrosion, so that defects, such as microcrack areas Q1, stress concentration areas Q2 and the like, which are near the connection via 61a and in its inner wall on the dielectric layer 61 made of glass, Si or SOI, may be thoroughly removed through the chemical corrosion. A content of HF in the solution is approximately in a range of 1% to 20%, and NH4F may or may not be contained in the solution. When NH4F is contained, a content of NH4F is approximately in a range of 10 to 40%, a temperature of the solution is approximately in a range of 35° C. to 60° C., a duration for the chemical corrosion is approximately in a range of 30 seconds to 5 minutes. Then, the dielectric layer 61 is thoroughly washed by the pure deionized water, and finally, is dried by the air knife. The chemically corroded connection via 61a has smooth inner wall and surface and does not contain the defects, such as microcrack areas Q1, stress concentration areas Q2 and the like.
S63, forming a chemical plating medium 620 on the first surface and the second surface of the dielectric layer 61 provided with the connection via 61a after the step S62.
In some examples, step S63 may specifically include: placing the dielectric layer 61, in a spraying mode or directly, into a water tank containing a solution of the chemical plating medium 620, so that a layer of Sn2+ is adsorbed on surfaces of the dielectric layer 61. The solution of the chemical plating medium 620 mainly contains SnCl2 of 10 g/L to 30 g/L, concentrated hydrochloric acid (having a concentration of 38%) of 20 ml/L to 60 ml/L and deionized water. A less number of Sn particles are added into the solution to prevent the Sn2+ from being oxidated. Then, the dielectric layer 61 is placed, in a spraying mode or directly, into a water tank containing an activation solution, so that surfaces of the dielectric layer 61 reacts with the activation solution (mainly containing SnCl2 of 80 g/L to 120 g/L, concentrated hydrochloric acid of 300 ml/L to 500 ml/L, Na2SnO3 of 10 g/L to 20 g/L, PdCl2 of 1 g/L to 4 g/L and deionized water), to generate metal palladium particles which are tightly attached to the surfaces of the dielectric layer 61. That is, the chemical plating medium 620 is formed on the first surface and the second surface of the dielectric layer 61 provided with the connection via 61a.
S64, after the step S63, performing a chemical plating process on the dielectric layer 61 with the chemical plating medium 620 to form metal films on the first surface and the second surface of the dielectric layer 61, and in the connection via 61a, and patterning the metal films formed on the first surface and the second surface of the dielectric layer 61, for forming a first extraction electrode 6201 and a second extraction electrode 6202, and a connection electrode 6203 in the connection via 61a.
In some examples, the chemically plated metal films may be a single-layer metal film or may be metal films stacked together. For example: only a Cu metal film is plated to form a single-layer metal film (having a thickness in a range of about 1 um to about 100 um). Alternatively, it is also possible to firstly plate a Ni metal film (having a thickness in a range of about 10 um to about 100 um), and then a Cu metal film (having a thickness in a range of about 1 um to about 100 um), wherein the Ni metal film is used to increase the adhesion of the Cu metal film. In the embodiment of the present disclosure, as an example, a material of the single-layer metal film is Cu, and a material of metal films stacked together is Ni/Cu, which does not limit the scope of the embodiment of the present disclosure. It will be described below by taking an example in which Ni/Cu metal films are chemically plated.
In some examples, step S64 may specifically include: placing the dielectric layer 61 into the chemical plating solution, and sequentially performing the chemical plating process with metal Ni and Cu. Then, the metal films formed on the first surface and the second surface of the dielectric layer 61 are patterned, for forming the first extraction electrode 6201 and the second extraction electrode 6202, and the connection electrode 6203 in the connection via 61a. The Ni solution for the chemical plating generally contains NiSO4·6H2O of 10 g/L to 30 g/L, NaH2PO4·2H2O 20 g/L to 40 g/L, Na-Citrate of 5 g/L to 15 g/L and NH4Cl of 20 g/L to 40 g/L, the solution is alkaline, has a PH in a range of 8.0 to 10.0 and a temperature in a range of 75° C. to 90° C. The Cu solution for the chemical plating generally contains KNaC4H4O6 of 30 g/L to 50 g/L, NaOH of 8 g/L to 10 g/L, Na2CO3 of 38 g/L to 40 g/L, CuSO4 of 10 g/L to 20 g/L, NiCl2 of 2 g/L to 6 g/L and formaldehyde of 40 ml/L to 60 ml/L with a concentration of 35%, the solution is alkaline, has a PH in a range of 11.0 to 14.0 and a temperature in a range of 55° C. to 65° C.
S71, preparing a dielectric layer 71, wherein a material of the dielectric layer 71 includes, but is not limited to, any one of glass, Si, SOI, GaAs, SiC, InP, PCB, Al2O3; forming a connection via 71a through a sand-blasting drilling process on the dielectric layer 71.
In some examples, step S71 may specifically include: forming high-speed injection beams through a sand-blasting process by using compressed air as power in combination with solid abrasive particles or liquid mixed with the solid abrasive particles, injecting the injection beams onto surfaces of the dielectric layer 71 at a high speed. The abrasive particles produce continuous cutting and impact on the surfaces of the dielectric layer 71, such that a via-shaped structure tapered from top to bottom may be formed by adjusting parameters, such as an air pressure, a beam injection angle, a beam track, a beam action time or the like. An inclination angle of the connection via 71a is approximately in a range of 15° to 45°. For example, the inclination angle of the connection via 71a is 30°. A diameter of a nozzle of a spray gun is in a range of about 10 um to about 50 um, a diameter of each abrasive particle is in a range of about 1 um to about 20 um, and abrasive particles may be selected from carborundum, corundum, calcium carbonate, quartz sand and the like. A thickness of the dielectric layer 71 is in a range of 0.1 mm to 2 mm, a diameter of an upper portion (on the second surface) of the connection via is in a range of about 0.5 mm to about 1.5 mm, and a diameter of a lower portion (on the first surface) of the connection via is in a range of about 0.3 mm to about 1.2 mm.
S72, cleaning the dielectric layer 71, after step S71, so that residues, debris (71b shown in
In some examples, step S72 may specifically include: placing the dielectric layer 71 into a water tank containing pure deionized water or a combination of the deionized water with a proper amount of cleaning agent (such as an oil-based cleaning agent or a water-based cleaning agent) at a temperature approximately in a range of 35° C. to 70° C., wherein the water is subjected to cavitation, acceleration and direct flow actions by means of ultrasonic waves (with a frequency approximately in a range of 10 kHz to 10 MHz), so that a pollutant layer is dispersed, emulsified and stripped to achieve the purpose of cleaning, wherein the cleaning time is approximately in a range of 2 to 20 minutes; and finally, washing the dielectric layer 71 by using the pure deionized water, and taking the dielectric layer 71 out of the water tank, and drying the dielectric layer 71 by using an air knife.
S73, forming metal films, as seed layers, within the connection via of the dielectric layer 71, and on the first surface and the second surface of the dielectric layer 71, after the step S72.
In some examples, step S73 may specifically include: depositing metal films with good conductivity, as seed layers, on the whole first surface and the whole second surface of the dielectric layer 71 through a process including, but being not limited to, a magnetron sputtering process. In addition to the magnetron sputtering process, the metal films may be formed through an electron beam evaporation process, an thermal evaporation process, or a pulsed laser sputtering process.
In some examples, a metal stack is generally used to increase the adhesion between the metal films 720 and the dielectric layer 71. That is, the metal films 720 include a first metal sub-layer and a second metal sub-layer sequentially arranged in a direction away from the dielectric layer. A material of the first metal sub-layer includes, but is not limited to, any one of titanium (Ti), molybdenum (Mo), and nickel (Ni), and a material of the second metal sub-layer includes, but is not limited to, any one of copper (Cu), silver (Ag), or gold (Au). For example, the metal films 720 include: any one of Ti/Cu, Mo/Cu, Ni/Cu, Ti/Ag, MWAg and Ni/Ag. In the embodiment of the present disclosure, a thickness of the first metal sub-layer is in a range of about 1 nm to about 100 nm; a thickness of the second metal sub-layer is in a range of about 50 nm to about 1000 nm. In addition, a thickness of the metal film on the inner wall of the connection via 71a is in a range of about 1 nm to about 200 nm.
S74, filling the connection via 71a through an electroplating process and thickening the metal films 720 formed on the first surface and the second surface, after the step S73, to form a first extraction electrode 7201 on the first surface and a second extraction electrode 7202 on the second surface, respectively, and a connection electrode 7203 within the connection via 71a.
In some examples, step S74 may specifically include: firstly, a via-filling electroplating process is performed in an electroplating bath through a reasonable combination of different types of electroplating solutions (such as a formula for filling the metal film into the connection via 71a and a formula for thickening the metal films on the whole surfaces), so that the metal film 720 (such as a first metal sub-layer in the metal film 720) is deposited on the inner wall of the connection via 71a, wherein an electroplating rate is in a range of 0.5 um/min to 5 um/min, and depending to an electroplating duration, the metal material may fully fill the connection via 71a (a thickness of the metal film is equal to 0.5 times of a diameter of the connection via 71a) or not fully fill the connection via 71a, only the inner wall of the connection via 71a is metallized (the thickness of the metal film is in a range of 500 nm to 10 um). That is, the connection electrode 7203 is formed. Then, the dielectric layer 71 is moved into the electroplating bath for the formula for thickening the metal films on the whole surfaces, to thicken the metal films 720 on the first surface and the second surface through an electroplating process, respectively, wherein the electroplating metal is Cu, Ag or Au, the electroplating rate is in a range of 0.5 um/min to 5 um/min, and depending to the electroplating duration, a thickness of each of the thickened metal films 720a is approximately in a range of 500 nm to 500 um. After the electroplating process, the surfaces of the dielectric layer 71 are generally undulated and uneven, which adversely affects subsequent processes. Thus, finally, a chemical mechanical polishing process is performed, such that the surfaces of the dielectric layer 71 become flat and smooth, thereby forming the first extraction electrode 7201 and the second extraction electrode 7202.
Alternatively, after the electroplating process, the thickened metal films 720a on the first surface and the second surface may be patterned, to form the first extraction electrode 7201 and the second extraction electrode 7202.
S81, preparing a dielectric layer 81, wherein a material of the dielectric layer 81 includes, but is not limited to, any one of glass, Si, SO, GaAs, SiC, InP, PCB, Al2O3; forming a connection via 81a through a sand-blasting drilling process on the dielectric layer 81.
In some examples, step S81 may specifically include: forming high-speed injection beams through a sand-blasting process by using compressed air as power in combination with solid abrasive particles or liquid mixed with the solid abrasive particles, injecting the injection beams onto surfaces of the dielectric layer 81 at a high speed. The abrasive particles produce continuous cutting and impact on the surfaces of the dielectric layer 81, such that a via-shaped structure tapered from top to bottom may be formed by adjusting parameters, such as an air pressure, a beam injection angle, a beam track, a beam action time or the like. An inclination angle of the connection via 81a is approximately in a range of 15° to 45°. For example, the inclination angle of the connection via 81a is 30°. A diameter of a nozzle of a spray gun is in a range of about 10 um to about 50 um, a diameter of each abrasive particle is in a range of about 1 um to about 20 um, and abrasive particles may be selected from carborundum, corundum, calcium carbonate, quartz sand and the like. A thickness of the dielectric layer 81 is in a range of 0.1 mm to 2 mm, a diameter of an upper portion (on the second surface) of the connection via Sla is in a range of about 0.5 mm to about 1.5 mm, and a diameter of a lower portion (on the first surface) of the connection via Sla is in a range of about 0.3 mm to about 1.2 mm.
S82, cleaning the dielectric layer 81, after step S81, so that residues, debris (81b shown in
In some examples, step S82 may specifically include: the dielectric layer 81 is placed into a water tank, wherein the dielectric layer 81 is firstly subjected to ultrasonic cleaning to remove floating dust on a surface of the dielectric layer; the dielectric layer 81 is then immersed in a solution containing hydrofluoric acid for chemical corrosion, so that defects, such as microcrack areas Q1, stress concentration areas Q2 and the like, which are near the connection via 81a and in its inner wall on the dielectric layer 81 made of glass, Si or SO, may be thoroughly removed through the chemical corrosion. A content of HF in the solution is approximately in a range of 1% to 20%, and NH4F may or may not be contained in the solution. When NH4F is contained, a content of NH4F is approximately in a range of 10 to 40%, a temperature of the solution is approximately in a range of 35° C. to 60° C., a duration for the chemical corrosion is approximately in a range of 30 seconds to 5 minutes. Then, the dielectric layer 81 is thoroughly washed by the pure deionized water, and finally, is dried by the air knife. The chemically corroded connection via 81a has smooth inner wall and surface and does not contain the defects, such as microcrack areas Q1, stress concentration areas Q2 and the like, which is beneficial to the growth of seed layers with a high quality, the via-filling and the thickening with metal.
S83, forming metal films, as seed layers, within the connection via of the dielectric layer 81, and on the first surface and the second surface of the dielectric layer 81, after the step S82.
In some examples, step S83 may specifically include: depositing metal films with good conductivity, as seed layers, on the whole first surface and the whole second surface of the dielectric layer 81 through a process including, but being not limited to, a magnetron sputtering process. In addition to the magnetron sputtering process, the metal films may be formed through an electron beam evaporation process, a thermal evaporation process, or a pulsed laser sputtering process.
In some examples, a metal stack is generally used to increase the adhesion between the metal films 820 and the dielectric layer 81. That is, the metal films 820 include a first metal sub-layer and a second metal sub-layer sequentially arranged in a direction away from the dielectric layer. A material of the first metal sub-layer includes, but is not limited to, any one of titanium (Ti), molybdenum (Mo), and nickel (Ni), and a material of the second metal sub-layer includes, but is not limited to, any one of copper (Cu), silver (Ag), or gold (Au). For example, the metal films 820 include: any one of Ti/Cu, Mo/Cu, Ni/Cu, Ti/Ag, Mo/Ag and Ni/Ag. In the embodiment of the present disclosure, a thickness of the first metal sub-layer is in a range of about 1 nm to about 100 nm; a thickness of the second metal sub-layer is in a range of about 50 nm to about 1000 nm. In addition, a thickness of the metal film on the inner wall of the connection via 81a is in a range of about 1 nm to about 200 nm.
S84, filling the connection via 81a through an electroplating process and thickening the metal films 820 formed on the first surface and the second surface, after the step S83, to form a first extraction electrode 8201 on the first surface and a second extraction electrode 8202 on the second surface, respectively, and a connection electrode 8203 within the connection via 81a.
In some examples, step S94 may specifically include: firstly, a via-filling electroplating process is performed in an electroplating bath through a reasonable combination of different types of electroplating solutions (such as a formula for filling the metal film into the connection via 81a and a formula for thickening the metal films on the whole surfaces), so that the metal film 820 (such as a first metal sub-layer in the metal film 820) is deposited on the inner wall of the connection via 81a, wherein an electroplating rate is in a range of 0.5 um/min to 5 um/min, and depending to an electroplating duration, the metal material may fully fill the connection via Sla (a thickness of the metal film is equal to 0.5 times of a diameter of the connection via Sla) or not fully fill the connection via Sla, only the inner wall of the connection via Sla is metallized (the thickness of the metal film is in a range of 500 nm to 10 um). That is, the connection electrode 8203 is formed. Then, the dielectric layer 81 is moved into the electroplating bath for the formula for thickening the metal films on the whole surfaces, to thicken the metal films 820 on the first surface and the second surface through an electroplating process, respectively, wherein the electroplating metal is Cu, Ag or Au, the electroplating rate is in a range of 0.5 um/min to 5 um/min, and depending to the electroplating duration, a thickness of each of the thickened metal films 820a is approximately in a range of 500 nm to 500 um. After the electroplating process, the surfaces of the dielectric layer 81 are generally undulated and uneven, which adversely affects subsequent processes. Thus, finally, a chemical mechanical polishing process is performed, such that the surfaces of the dielectric layer 81 become flat and smooth, thereby forming the first extraction electrode 8201 and the second extraction electrode 8202.
Alternatively, after the electroplating process, the thickened metal films 820a on the first surface and the second surface may be patterned, to form the first extraction electrode 8201 and the second extraction electrode 8202.
S91, preparing a dielectric layer 91, wherein a material of the dielectric layer 91 includes, but is not limited to, any one of glass, Si, SO, GaAs, SiC, InP, PCB, Al2O3; forming a connection via 91a through a sand-blasting drilling process on the dielectric layer 91.
In some examples, step S91 may specifically include: forming high-speed injection beams through a sand-blasting process by using compressed air as power in combination with solid abrasive particles or liquid mixed with the solid abrasive particles, injecting the injection beams onto surfaces of the dielectric layer 91 at a high speed. The abrasive particles produce continuous cutting and impact on the surfaces of the dielectric layer 91, such that a via-shaped structure tapered from top to bottom may be formed by adjusting parameters, such as an air pressure, a beam injection angle, a beam track, a beam action time or the like. An inclination angle of the connection via 91a is approximately in a range of 15° to 45°. For example, the inclination angle of the connection via 91a is 30°. A diameter of a nozzle of a spray gun is in a range of about 10 um to about 50 um, a diameter of each abrasive particle is in a range of about 1 um to about 20 um, and abrasive particles may be selected from carborundum, corundum, calcium carbonate, quartz sand and the like. A thickness of the dielectric layer 91 is in a range of 0.1 mm to 2 mm, a diameter of an upper portion (on the second surface) of the connection via 91a is in a range of about 0.5 mm to about 1.5 mm, and a diameter of a lower portion (on the first surface) of the connection via 91a is in a range of about 0.3 mm to about 1.2 mm.
S92, cleaning the dielectric layer 91, after step S91, so that residues, debris (91b shown in
In some examples, step S92 may specifically include: placing the dielectric layer 91 into a water tank containing pure deionized water or a combination of the deionized water with a proper amount of cleaning agent (such as an oil-based cleaning agent or a water-based cleaning agent) at a temperature approximately in a range of 35° C. to 70° C., wherein the water is subjected to cavitation, acceleration and direct flow actions by means of ultrasonic waves (with a frequency approximately in a range of 10 kHz to 10 MHz), so that a pollutant layer is dispersed, emulsified and stripped to achieve the purpose of cleaning, wherein the cleaning time is approximately in a range of 2 to 20 minutes; and finally, washing the dielectric layer 91 by using the pure deionized water, and taking the dielectric layer 91 out of the water tank, and drying the dielectric layer 91 by using an air knife.
S93, after the step S92, applying a metal paste 920 into the connection via 91a of the dielectric layer 91, and forming the metal paste 920 on the first surface and the second surface of the dielectric layer 91; and then, curing the metal paste 920 on the first surface and the second surface, respectively, to form a connection electrode 9203 filled in the connection via 91a, a first extraction electrode 9201 on the first surface and a second extraction electrode 9202 on the second surface.
In some examples, the metal paste 920 may be a conductive paste. A material of the conductive paste includes, but is not limited to, a low-temperature curing type polymer conductive paste, and main components of the conductive paste include conductive particles, a resin, a curing agent, a dispersant, a diluent, an adhesion enhancer, and an anti-settling agent. The conductive particles may be selected from Cu, Ag and Au, and a size of each particle is approximately in a range of 1 nm to 100 um. The resin may be bisphenol epoxy resin. The curing agent may be acid anhydrides. The dispersant may be methylimidazole. The diluent may be butyl acetate. The adhesion enhancer may be tetraethyl titanate. The anti-settling agent may be polyamides.
Step S93 may specifically include: firstly, coating the conductive paste in the connection via 91a and around an edge of the connection via 91a on the second surface, and then, performing solvent drying and thermocuring processes on the second surface of the dielectric layer 91 to form the connection electrode 9203 filled in the connection via 91a and the second extraction electrode 9202 located on the second surface; then, coating the conductive paste around an edge of the connection via 91a on the first surface of the dielectric layer 91, and then, performing solvent drying and thermocuring processes on the first surface of the dielectric layer 91 to form the first extraction electrode 9201 located on the first surface. The preferred mode for coating the conductive paste includes, but is not limited to, screen printing, ink-jet printing, slit coating or the like. A vacuum adsorption machine is used in cooperation when the conductive paste is coated, so that the coating efficiency may be improved, and a distribution profile of the conductive paste on the wall and the edge of the connection via may be improved. The solvent drying process may be performed under an atmospheric pressure of air, an atmospheric pressure of N2 or the vacuum, at a temperature in a range of about 40° C. to about 95° C., for a duration in a range of about 1 min to about 30 min. The thermocuring process may be performed in an oven, under the atmosphere of N2, at a heating temperature in a range of about 140° C. to about 200° C. Alternatively, the curing process may be performed by means of illumination with laser beams, which have a wavelength in a range of about 500 nm to about 1510 nm, a laser power in a range of 50 mW to 50 W, and a beam diameter in a range of about 10 um to about 2000 um, and the laser beams may be a single beam or multiple beams.
S101, preparing a dielectric layer 101, wherein a material of the dielectric layer 101 includes, but is not limited to, any one of glass, Si, SOI, GaAs, SiC, InP, PCB, Al2O3; forming a connection via 101a through a sand-blasting drilling process on the dielectric layer 101.
In some examples, step S101 may specifically include: forming high-speed injection beams through a sand-blasting process by using compressed air as power in combination with solid abrasive particles or liquid mixed with the solid abrasive particles, injecting the injection beams onto surfaces of the dielectric layer 101 at a high speed. The abrasive particles produce continuous cutting and impact on the surfaces of the dielectric layer 101, such that a via-shaped structure tapered from top to bottom may be formed by adjusting parameters, such as an air pressure, a beam injection angle, a beam track, a beam action time or the like. An inclination angle of the connection via 101a is approximately in a range of 15° to 45°. For example, the inclination angle of the connection via 101a is 30°. A diameter of a nozzle of a spray gun is in a range of about 10 um to about 50 um, a diameter of each abrasive particle is in a range of about 1 um to about 20 um, and abrasive particles may be selected from carborundum, corundum, calcium carbonate, quartz sand and the like. A thickness of the dielectric layer 101 is in a range of 0.1 mm to 2 mm, a diameter of an upper portion (on the second surface) of the connection via 101a is in a range of about 0.5 mm to about 1.5 mm, and a diameter of a lower portion (on the first surface) of the connection via 101a is in a range of about 0.3 mm to about 1.2 mm.
S102, cleaning the dielectric layer 101, after step S101, so that residues, debris (101b shown in
In some examples, step S102 may specifically include: the dielectric layer 101 is placed into a water tank, wherein the dielectric layer 101 is firstly subjected to ultrasonic cleaning to remove floating dust on a surface of the dielectric layer; the dielectric layer 101 is then immersed in a solution containing hydrofluoric acid for chemical corrosion, so that defects, such as microcrack areas Q1, stress concentration areas Q2 and the like, which are near the connection via 101a and in its inner wall on the dielectric layer 101 made of glass, Si or SO, may be thoroughly removed through the chemical corrosion. A content of HF in the solution is approximately in a range of 1% to 20%, and NH4F may or may not be contained in the solution. When NH4F is contained, a content of NH4F is approximately in a range of 10 to 40%, a temperature of the solution is approximately in a range of 35° C. to 60° C., a duration for the chemical corrosion is approximately in a range of 30 seconds to 5 minutes. Then, the dielectric layer 101 is thoroughly washed by the pure deionized water, and finally, is dried by the air knife. The chemically corroded connection via 101a has smooth inner wall and surface and does not contain the defects, such as microcrack areas Q1, stress concentration areas Q2 and the like, which is beneficial to the growth of seed layers with a high quality, the via-filling and the thickening with metal.
S103, after the step S102, applying a metal paste into the connection via 101a of the dielectric layer 101, and forming the metal paste on the first surface and the second surface of the dielectric layer 101; and then, curing the metal paste on the first surface and the second surface, respectively, to form a connection electrode 10203 filled in the connection via 101a, a first extraction electrode 10201 on the first surface and a second extraction electrode 10202 on the second surface.
In some examples, the metal paste may be a conductive paste. A material of the conductive paste includes, but is not limited to, a low-temperature curing type polymer conductive paste, and main components of the conductive paste include conductive particles, a resin, a curing agent, a dispersant, a diluent, an adhesion enhancer, and an anti-settling agent. The conductive particles may be selected from Cu, Ag and Au, and a size of each particle is approximately in a range of 1 nm to 100 um. The resin may be bisphenol epoxy resin. The curing agent may be acid anhydrides. The dispersant may be methylimidazole. The diluent may be butyl acetate. The adhesion enhancer may be tetraethyl titanate. The anti-settling agent may be polyamides.
Step S103 may specifically include: firstly, coating the conductive paste in the connection via 101a and around an edge of the connection via 101a on the second surface, and then, performing solvent drying and thermocuring processes on the second surface of the dielectric layer 101 to form the connection electrode 10203 filled in the connection via 101a and the second extraction electrode 10202 located on the second surface; then, coating the conductive paste around an edge of the connection via 101a on the first surface of the dielectric layer 101, and then, performing solvent drying and thermocuring processes on the first surface of the dielectric layer 101 to form the first extraction electrode 10201 located on the first surface. The preferred mode for coating the conductive paste includes, but is not limited to, screen printing, ink-jet printing, slit coating or the like. A vacuum adsorption machine is used in cooperation when the conductive paste is coated, so that the coating efficiency may be improved, and a distribution profile of the conductive paste on the wall and the edge of the connection via may be improved. The solvent drying process may be performed under an atmospheric pressure of air, an atmospheric pressure of N2 or the vacuum, at a temperature in a range of about 40° C. to about 95° C., for a duration in a range of about 1 min to about 30 min. The thermocuring process may be performed in an oven, under the atmosphere of N2, at a heating temperature in a range of about 140° C. to about 200° C. Alternatively, the curing process may be performed by means of illumination with laser beams, which have a wavelength in a range of about 500 nm to about 1510 nm, a laser power in a range of 50 mW to 50 W, and a beam diameter in a range of about 10 um to about 2000 um, and the laser beams may be a single beam or multiple beams.
S111, preparing a dielectric layer 111, wherein a material of the dielectric layer 111 includes, but is not limited to, any one of glass, Si, SOI, GaAs, SiC, InP, PCB, Al2O3; forming a connection via 111a through a sand-blasting drilling process on the dielectric layer 111.
In some examples, step S111 may specifically include: forming high-speed injection beams through a sand-blasting process by using compressed air as power in combination with solid abrasive particles or liquid mixed with the solid abrasive particles, injecting the injection beams onto surfaces of the dielectric layer 111 at a high speed. The abrasive particles produce continuous cutting and impact on the surfaces of the dielectric layer 111, such that a via-shaped structure tapered from top to bottom may be formed by adjusting parameters, such as an air pressure, a beam injection angle, a beam track, a beam action time or the like. An inclination angle of the connection via 111a is approximately in a range of 15° to 45°. For example, the inclination angle of the connection via 111a is 30°. A diameter of a nozzle of a spray gun is in a range of about 10 um to about 50 um, a diameter of each abrasive particle is in a range of about 1 um to about 20 um, and abrasive particles may be selected from carborundum, corundum, calcium carbonate, quartz sand and the like. A thickness of the dielectric layer 111 is in a range of 0.1 mm to 2 mm, a diameter of an upper portion (on the second surface) of the connection via 111a is in a range of about 0.5 mm to about 1.5 mm, and a diameter of a lower portion (on the first surface) of the connection via 111a is in a range of about 0.3 mm to about 1.2 mm.
S112, cleaning the dielectric layer 111, after step S111, so that residues, debris (111b shown in
In some examples, step S112 may specifically include: placing the dielectric layer 111 into a water tank containing pure deionized water or a combination of the deionized water with a proper amount of cleaning agent (such as an oil-based cleaning agent or a water-based cleaning agent) at a temperature approximately in a range of 35° C. to 70° C., wherein the water is subjected to cavitation, acceleration and direct flow actions by means of ultrasonic waves (with a frequency approximately in a range of 10 kHz to 10 MHz), so that a pollutant layer is dispersed, emulsified and stripped to achieve the purpose of cleaning, wherein the cleaning time is approximately in a range of 2 to 20 minutes; and finally, washing the dielectric layer 111 by using the pure deionized water, and taking the dielectric layer 111 out of the water tank, and drying the dielectric layer 111 by using an air knife.
S113, forming a chemical plating medium 1120 on the first surface and the second surface of the dielectric layer 111 provided with the connection via 111a after the step S112.
In some examples, step S113 may specifically include: placing the dielectric layer 111, in a spraying mode or directly, into a water tank containing a solution of the chemical plating medium 1120, so that a layer of Sn2+ is adsorbed on surfaces of the dielectric layer 111. The solution of the chemical plating medium 1120 mainly contains SnCl2 of 10 g/L to 30 g/L, concentrated hydrochloric acid (having a concentration of 38%) of 20 ml/L to 60 ml/L and deionized water. A less number of Sn particles are added into the solution to prevent the Sn2+ from being oxidated. Then, the dielectric layer 111 is placed, in a spraying mode or directly, into a water tank containing an activation solution, so that surfaces of the dielectric layer III reacts with the activation solution (mainly containing SnCl2 of 80 g/L to 120 g/L, concentrated hydrochloric acid of 300 ml/L to 500 ml/L, Na2SnO3 of 10 g/L to 20 g/L, PdCl2 of 1 g/L to 4 g/L and deionized water), to generate metal palladium particles which are tightly attached to the surfaces of the dielectric layer 111. That is, the chemical plating medium 1120 is formed on the first surface and the second surface of the dielectric layer III provided with the connection via 111a.
S114, after the step S113, performing a chemical plating process on the dielectric layer III with the chemical plating medium 1120 to form metal films on the first surface and the second surface of the dielectric layer 111, and in the connection via 111a, and patterning the metal films formed on the first surface and the second surface of the dielectric layer 111, for forming a first extraction electrode 11201 and a second extraction electrode 11202, and a connection electrode 11203 in the connection via 111a.
In some examples, the chemically plated metal films may be a single-layer metal film or may be metal films stacked together. For example: only a Cu metal film is plated to form a single-layer metal film (having a thickness in a range of about 1 um to about 100 um). Alternatively, it is also possible to firstly plate a Ni metal film (having a thickness in a range of about 10 um to about 100 um), and then a Cu metal film (having a thickness in a range of about 1 um to about 100 um), wherein the Ni metal film is used to increase the adhesion of the Cu metal film. In the embodiment of the present disclosure, as an example, a material of the single-layer metal film is Cu, and a material of metal films stacked together is Ni/Cu, which does not limit the scope of the embodiment of the present disclosure. It will be described below by taking an example in which Ni/Cu metal films are chemically plated.
In some examples, step S114 may specifically include: placing the dielectric layer III into the chemical plating solution, and sequentially performing the chemical plating process with metal Ni and Cu. Then, the metal films formed on the first surface and the second surface of the dielectric layer III are patterned, for forming the first extraction electrode 11201 and the second extraction electrode 11202, and the connection electrode 11203 in the connection via 111a. The Ni solution for the chemical plating generally contains NiSO4·6H2O of 10 g/L to 30 g/L, NaH2PO4·2H2O 20 g/L to 40 g/L, Na-Citrate of 5 g/L to 15 g/L and NH4Cl of 20 g/L to 40 g/L, the solution is alkaline, has a PH in a range of 8.0 to 10.0 and a temperature in a range of 75° C. to 90° C. The Cu solution for the chemical plating generally contains KNaC4H4O6 of 30 g/L to 50 g/L, NaOH of 8 g/L to 10 g/L, Na2CO3 of 38 g/L to 40 g/L, CuSO4 of 10 g/L to 20 g/L, NiCl2 of 2 g/L to 6 g/L and formaldehyde of 40 ml/L to 60 ml/L with a concentration of 35%, the solution is alkaline, has a PH in a range of 11.0 to 14.0 and a temperature in a range of 55° C. to 65° C.
S121, preparing a dielectric layer 121, wherein a material of the dielectric layer 121 includes, but is not limited to, any one of glass, Si, SOI, GaAs, SiC, InP, PCB, Al2O3; forming a connection via 121a through a sand-blasting drilling process on the dielectric layer 121.
In some examples, step S121 may specifically include: forming high-speed injection beams through a sand-blasting process by using compressed air as power in combination with solid abrasive particles or liquid mixed with the solid abrasive particles, injecting the injection beams onto surfaces of the dielectric layer 121 at a high speed. The abrasive particles produce continuous cutting and impact on the surfaces of the dielectric layer 121, such that a via-shaped structure tapered from top to bottom may be formed by adjusting parameters, such as an air pressure, a beam injection angle, a beam track, a beam action time or the like. An inclination angle of the connection via 121a is approximately in a range of 15° to 45°. For example, the inclination angle of the connection via 121a is 30°. A diameter of a nozzle of a spray gun is in a range of about 10 um to about 50 um, a diameter of each abrasive particle is in a range of about 1 um to about 20 um, and abrasive particles may be selected from carborundum, corundum, calcium carbonate, quartz sand and the like. A thickness of the dielectric layer 121 is in a range of 0.1 mm to 2 mm, a diameter of an upper portion (on the second surface) of the connection via 121a is in a range of about 0.5 mm to about 1.5 mm, and a diameter of a lower portion (on the first surface) of the connection via 121a is in a range of about 0.3 mm to about 1.2 mm.
S122, cleaning the dielectric layer 121, after step S121, so that residues, debris (121b shown in
In some examples, step S122 may specifically include: the dielectric layer 121 is placed into a water tank, wherein the dielectric layer 121 is firstly subjected to ultrasonic cleaning to remove floating dust on a surface of the dielectric layer; the dielectric layer 121 is then immersed in a solution containing hydrofluoric acid for chemical corrosion, so that defects, such as microcrack areas Q1, stress concentration areas Q2 and the like, which are near the connection via 121a and in its inner wall on the dielectric layer 121 made of glass, Si or SOL, may be thoroughly removed through the chemical corrosion. A content of HF in the solution is approximately in a range of 1% to 20%, and NH4F may or may not be contained in the solution. When NH4F is contained, a content of NH4F is approximately in a range of 10 to 40%, a temperature of the solution is approximately in a range of 35° C. to 60° C., a duration for the chemical corrosion is approximately in a range of 30 seconds to 5 minutes. Then, the dielectric layer 121 is thoroughly washed by the pure deionized water, and finally, is dried by the air knife. The chemically corroded connection via 121a has smooth inner wall and surface and does not contain the defects, such as microcrack areas Q1, stress concentration areas Q2 and the like.
S123, forming a chemical plating medium 1220 on the first surface and the second surface of the dielectric layer 121 provided with the connection via 121a after the step S122.
In some examples, step S123 may specifically include: placing the dielectric layer 121, in a spraying mode or directly, into a water tank containing a solution of the chemical plating medium 1220, so that a layer of Sn2+ is adsorbed on surfaces of the dielectric layer 121. The solution of the chemical plating medium 1220 mainly contains SnCl2 of 10 g/L to 30 g/L, concentrated hydrochloric acid (having a concentration of 38%) of 20 ml/L to 60 ml/L and deionized water. A less number of Sn particles are added into the solution to prevent the Sn2+ from being oxidated. Then, the dielectric layer 121 is placed, in a spraying mode or directly, into a water tank containing an activation solution, so that surfaces of the dielectric layer 121 reacts with the activation solution (mainly containing SnCl2 of 80 g/L to 120 g/L, concentrated hydrochloric acid of 300 ml/L to 500 ml/L, Na2SnO3 of 10 g/L to 20 g/L, PdCl2 of 1 g/L to 4 g/L and deionized water), to generate metal palladium particles which are tightly attached to the surfaces of the dielectric layer 121. That is, the chemical plating medium 1220 is formed on the first surface and the second surface of the dielectric layer 121 provided with the connection via 121a.
S124, after the step S123, performing a chemical plating process on the dielectric layer 121 with the chemical plating medium 1220 to form metal films on the the first surface, the second surface of the dielectric layer 121, and in the connection via 121a, and patterning the metal films formed on the first surface and the second surface of the dielectric layer 121, for forming a first extraction electrode 12201 and a second extraction electrode 12202, and a connection electrode 12203 in the connection via 121a.
In some examples, the chemically plated metal films may be a single-layer metal film or may be metal films stacked together. For example: only a Cu metal film is plated to form a single-layer metal film (having a thickness in a range of about 1 um to about 100 um). Alternatively, it is also possible to firstly plate a Ni metal film (having a thickness in a range of about 10 um to about 100 um), and then a Cu metal film (having a thickness in a range of about 1 um to about 100 um), wherein the Ni metal film is used to increase the adhesion of the Cu metal film. In the embodiment of the present disclosure, as an example, a material of the single-layer metal film is Cu, and a material of metal films stacked together is Ni/Cu, which does not limit the scope of the embodiment of the present disclosure. It will be described below by taking an example in which Ni/Cu metal films are chemically plated.
In some examples, step S124 may specifically include: placing the dielectric layer 121 into the chemical plating solution, and sequentially performing the chemical plating process with metal Ni and Cu. Then, the metal films formed on the first surface and the second surface of the dielectric layer 121 are patterned, for forming the first extraction electrode 12201 and the second extraction electrode 12202, and the connection electrode 12203 in the connection via 121a. The Ni solution for the chemical plating generally contains NiSO4·6H2O of 10 g/L to 30 g/L, NaH2PO4·2H2O 20 g/L to 40 g/L, Na-Citrate of 5 g/L to 15 g/L and NH4Cl of 20 g/L to 40 g/L, the solution is alkaline, has a PH in a range of 8.0 to 10.0 and a temperature in a range of 75° C. to 90° C. The Cu solution for the chemical plating generally contains KNaC4H406 of 30 g/L to 50 g/L, NaOH of 8 g/L to 10 g/L, Na2CO3 of 38 g/L to 40 g/L, CuSO4 of 10 g/L to 20 g/L, NiCl2 of 2 g/L to 6 g/L and formaldehyde of 40 ml/L to 60 ml/L with a concentration of 35%, the solution is alkaline, has a PH in a range of 11.0 to 14.0 and a temperature in a range of 55° C. to 65° C.
S131, preparing a dielectric layer 131, wherein a material of the dielectric layer 131 includes, but is not limited to, any one of glass, Si, SOI, GaAs, SiC, InP, PCB, Al2O3; forming a connection via 131a through a laser drilling process on the dielectric layer 131.
In some examples, step S131 may specifically include: vertically irradiating a laser onto a surface (a first surface or a second surface) of the dielectric layer 131 by means of a laser device. When the laser interacts with the dielectric layer 131, atoms forming the dielectric layer 131 are ionized and projected out of the surface of the dielectric layer 131 due to higher photon energy of the laser, and the drilled via is gradually deepened along with time, until the whole dielectric layer 131 is penetrated. That is, the connection via 131a is formed. An inclination angle of the connection via 131a is approximately in a range of 0° to 5°. For example, the inclination angle of the connection via 131a is 5°. That is, the connection via 131a has a shape like a cylinder or a truncated cone, an inverted truncated cone. Generally, the laser has a wavelength selected from 532 nm, 355 nm, 266 nm, 248 nm, 197 nm or the like, the laser may have a pulse width selected from 1 fs to 100 fs, 1 ps to 100 ps, 1 ns to 100 ns or the like, and a type of the laser device may be selected from a continuous laser device, a pulse laser device or the like. The laser drilling includes the following two modes: when a diameter of a light spot is large, a relative position between a laser beam and the dielectric layer 131 is fixed, the dielectric layer 131 is directly penetrated by means of the high energy, such that a shape of the connection via 131a is the inverted truncated cone, and diameters of the connection via are gradually reduced from top to bottom (along a propagation direction of the laser). The diameter of the connection via 131a on the second surface is in a range of about 80 um to about 120 um, and the diameter of the connection via 131a on the first surface is in a range of about 60 um to about 100 um. The other mode of the laser drilling is: when the diameter of the light spot is small, the laser beam moves (scans) in circles on the dielectric layer 131. Specifically, a focal point of the light spot is constantly changed, a depth of the focal point is constantly changed, the laser beam moves in a spiral line from a lower surface of the dielectric layer 131 to an upper surface of the dielectric layer 131, and radiuses of the spiral line are gradually reduced from the lower surface to the upper surface. In this way, a portion of the dielectric layer 131 is obtained through the laser cut and is truncated cone shaped, and falls down due to the gravity, thereby forming the connection via 131a which is truncated cone shaped. The diameter of the connection via 131a on the second surface is in a range of about 100 um to about 1000 um, and the diameter of the connection via 131a on the first surface is in a range of about 150 um to about 1500 um.
S132, cleaning the dielectric layer 131, after step S131, so that residues, debris, and the like near the inner wall and an outer edge of the connection via 131a are washed away.
In some examples, step S132 may specifically include: placing the dielectric layer 131 into a water tank containing pure deionized water or a combination of the deionized water with a proper amount of cleaning agent (such as an oil-based cleaning agent or a water-based cleaning agent) at a temperature approximately in a range of 35° C. to 70° C., wherein the water is subjected to cavitation, acceleration and direct flow actions by means of ultrasonic waves (with a frequency approximately in a range of 10 kHz to 10 MHz), so that a pollutant layer is dispersed, emulsified and stripped to achieve the purpose of cleaning, wherein the cleaning time is approximately in a range of 2 to 20 minutes; and finally, washing the dielectric layer 131 by using the pure deionized water, and taking the dielectric layer 11 out of the water tank, and drying the dielectric layer 11 by using an air knife.
S133, forming metal films 1320, as seed layers, within the connection via 131a of the dielectric layer 131, and on the first surface and the second surface of the dielectric layer 131, after the step S132.
In some examples, step S133 may specifically include: depositing metal films 1320 with good conductivity, as seed layers, on the whole first surface and the whole second surface of the dielectric layer 131 through a process including, but being not limited to, a magnetron sputtering process. In addition to the magnetron sputtering process, the metal films 1320 may be formed through an electron beam evaporation process, an thermal evaporation process, or a pulsed laser sputtering process.
In some examples, a metal stack is generally used to increase the adhesion between the metal films and the dielectric layer 131. That is, the metal films include a first metal sub-layer and a second metal sub-layer sequentially arranged in a direction away from the dielectric layer 131. A material of the first metal sub-layer includes, but is not limited to, any one of titanium (Ti), molybdenum (Mo), and nickel (Ni), and a material of the second metal sub-layer includes, but is not limited to, any one of copper (Cu), silver (Ag), or gold (Au). For example, the metal films include: any one of Ti/Cu, Mo/Cu, Ni/Cu, Ti/Ag, MWAg and Ni/Ag. In the embodiment of the present disclosure, a thickness of the first metal sub-layer is in a range of about 1 nm to about 100 nm; a thickness of the second metal sub-layer is in a range of about 50 nm to about 1000 nm. In addition, a thickness of the metal film on the inner wall of the connection via 131a is in a range of about 1 nm to about 200 nm.
S134, filling the connection via 131a through an electroplating process and thickening the metal films 1320 formed on the first surface and the second surface, after the step S133, to form a first extraction electrode 13201 on the first surface and a second extraction electrode 13202 on the second surface, respectively, and a connection electrode 13203 within the connection via 131a.
In some examples, step S134 may specifically include: firstly, a via-filling electroplating process is performed in an electroplating bath through a reasonable combination of different types of electroplating solutions (such as a formula for filling the metal film into the connection via 131a and a formula for thickening the metal films on the whole surfaces), so that the metal film 1320 (such as a first metal sub-layer in the metal film 1320) is deposited on the inner wall of the connection via 131a, wherein an electroplating rate is in a range of 0.5 um/min to 5 um/min, and depending to an electroplating duration, the metal material may fully fill the connection via 131a (a thickness of the metal film is equal to 0.5 times of a diameter of the connection via 131a) or not fully fill the connection via 131a, only the inner wall of the connection via 131a is metallized (the thickness of the metal film is in a range of 500 nm to 10 um). That is, the connection electrode 13203 is formed. Then, the dielectric layer 131 is moved into the electroplating bath for the formula for thickening the metal films on the whole surfaces, to thicken the metal films 1320 on the first surface and the second surface through an electroplating process, respectively, wherein the electroplating metal is Cu, Ag or Au, the electroplating rate is in a range of 0.5 um/min to 5 um/min, and depending to the electroplating duration, a thickness of each of the thickened metal films 1320a is approximatively in a range of 500 nm to 500 um. After the electroplating process, the surfaces of the dielectric layer 131 are generally undulated and uneven, which adversely affects subsequent processes. Thus, finally, a chemical mechanical polishing process is performed, such that the surfaces of the dielectric layer 131 become flat and smooth, thereby forming the first extraction electrode 13201 and the second extraction electrode 13202.
Alternatively, after the electroplating process, the thickened metal films 1320a on the first surface and the second surface may be patterned, to form the first extraction electrode 13201 and the second extraction electrode 13202.
S141, preparing a dielectric layer 141, wherein a material of the dielectric layer 141 includes, but is not limited to, any one of glass, Si, SOI; forming a connection via 141a through a laser drilling process on the dielectric layer 141.
In some examples, step S141 may specifically include: vertically irradiating a laser onto a surface (a first surface or a second surface) of the dielectric layer 141 by means of a laser device. When the laser interacts with the dielectric layer 141, atoms forming the dielectric layer 141 are ionized and projected out of the surface of the dielectric layer 141 due to higher photon energy of the laser, and the drilled via is gradually deepened along with time, until the whole dielectric layer 141 is penetrated. That is, the connection via 141a is formed. An inclination angle of the connection via 141a is approximately in a range of 0° to 5°. For example, the inclination angle of the connection via 141a is 5°. That is, the connection via 141a has a shape like a cylinder or a truncated cone, an inverted truncated cone. Generally, the laser has a wavelength selected from 532 nm, 355 nm, 266 nm, 248 nm, 197 nm or the like, the laser may have a pulse width selected from 1 fs to 100 fs, 1 ps to 100 ps, 1 ns to 100 ns or the like, and a type of the laser device may be selected from a continuous laser device, a pulse laser device or the like. The laser drilling includes the following two modes: when a diameter of a light spot is large, a relative position between a laser beam and the dielectric layer 141 is fixed, the dielectric layer 141 is directly penetrated by means of the high energy, such that a shape of the connection via 141a is the inverted truncated cone, and diameters of the connection via are gradually reduced from top to bottom (along a propagation direction of the laser). The diameter of the connection via 141a on the second surface is in a range of about 80 um to about 120 um, and the diameter of the connection via 141a on the first surface is in a range of about 60 um to about 100 um. The other mode of the laser drilling is: when the diameter of the light spot is small, the laser beam moves (scans) in circles on the dielectric layer 141. Specifically, a focal point of the light spot is constantly changed, a depth of the focal point is constantly changed, the laser beam moves in a spiral line from a lower surface of the dielectric layer 141 to an upper surface of the dielectric layer 141, and radiuses of the spiral line are gradually reduced from the lower surface to the upper surface. In this way, a portion of the dielectric layer 141 is obtained through the laser cut and is truncated cone shaped, and falls down due to the gravity, thereby forming the connection via 141a which is truncated cone shaped. The diameter of the connection via 141a on the second surface is in a range of about 100 um to about 1000 um, and the diameter of the connection via 141a on the first surface is in a range of about 150 um to about 1500 um.
S142, cleaning the dielectric layer 141, after step S141, so that residues, debris, and the like near the inner wall and an outer edge of the connection via 141a are washed away.
In some examples, step S142 may specifically include: the dielectric layer 141 is placed into a water tank, wherein the dielectric layer 141 is firstly subjected to ultrasonic cleaning to remove floating dust on a surface of the dielectric layer, the dielectric layer 141 is then immersed in a solution containing hydrofluoric acid for chemical corrosion, so that defects, such as microcrack areas Q1, stress concentration areas Q2 and the like, which are near the connection via 141a and in its inner wall on the dielectric layer 141 made of glass, Si or SOI, may be thoroughly removed through the chemical corrosion. A content of HF in the solution is approximately in a range of 1% to 20%, and NH4F may or may not be contained in the solution. When NH4F is contained, a content of NH4F is approximately in a range of 10 to 40%, a temperature of the solution is approximately in a range of 35° C. to 60° C., a duration for the chemical corrosion is approximately in a range of 30 seconds to 5 minutes. Then, the dielectric layer 141 is thoroughly washed by the pure deionized water, and finally, is dried by the air knife. The chemically corroded connection via 141a has smooth inner wall and surface and does not contain the defects, such as microcrack areas Q1, stress concentration areas Q2 and the like, which is beneficial to the growth of seed layers with a high quality, the via-filling and the thickening with metal.
S143, forming metal films 1420, as seed layers, within the connection via 141a of the dielectric layer 141, and on the first surface and the second surface of the dielectric layer 141, after the step S142.
In some examples, step S143 may specifically include: depositing metal films 1420 with good conductivity, as seed layers, on the whole first surface and the whole second surface of the dielectric layer 141 through a process including, but being not limited to, a magnetron sputtering process. In addition to the magnetron sputtering process, the metal films 1420 may be formed through an electron beam evaporation process, an thermal evaporation process, or a pulsed laser sputtering process.
In some examples, a metal stack is generally used to increase the adhesion between the metal films and the dielectric layer 141. That is, the metal films include a first metal sub-layer and a second metal sub-layer sequentially arranged in a direction away from the dielectric layer 141. A material of the first metal sub-layer includes, but is not limited to, any one of titanium (Ti), molybdenum (Mo), and nickel (Ni), and a material of the second metal sub-layer includes, but is not limited to, any one of copper (Cu), silver (Ag), or gold (Au). For example, the metal films include: any one of Ti/Cu, Mo/Cu, Ni/Cu, Ti/Ag, MWAg and Ni/Ag. In the embodiment of the present disclosure, a thickness of the first metal sub-layer is in a range of about 1 nm to about 100 nm; a thickness of the second metal sub-layer is in a range of about 50 nm to about 1000 nm. In addition, a thickness of the metal film on the inner wall of the connection via 141a is in a range of about 1 nm to about 200 nm.
S144, filling the connection via 141a through an electroplating process and thickening the metal films 1420 formed on the first surface and the second surface, after the step S143, to form a first extraction electrode 14201 on the first surface and a second extraction electrode 14202 on the second surface, respectively, and a connection electrode 14203 within the connection via 141a.
In some examples, step S144 may specifically include: firstly, a via-filling electroplating process is performed in an electroplating bath through a reasonable combination of different types of electroplating solutions (such as a formula for filling the metal film into the connection via 141a and a formula for thickening the metal films on the whole surfaces), so that the metal film 1420 (such as a first metal sub-layer in the metal film 1420) is deposited on the inner wall of the connection via 141a, wherein an electroplating rate is in a range of 0.5 um/min to 5 um/min, and depending to an electroplating duration, the metal material may fully fill the connection via 141a (a thickness of the metal film is equal to 0.5 times of a diameter of the connection via 141a) or not fully fill the connection via 141a, only the inner wall of the connection via 141a is metallized (the thickness of the metal film is in a range of 500 nm to 10 um). That is, the connection electrode 14203 is formed. Then, the dielectric layer 141 is moved into the electroplating bath for the formula for thickening the metal films on the whole surfaces, to thicken the metal films 1420 on the first surface and the second surface through an electroplating process, respectively, wherein the electroplating metal is Cu, Ag or Au, the electroplating rate is in a range of 0.5 um/min to 5 um/min, and depending to the electroplating duration, a thickness of each of the thickened metal films 1420a is approximately in a range of 500 nm to 500 um. After the electroplating process, the surfaces of the dielectric layer 141 are generally undulated and uneven, which adversely affects subsequent processes. Thus, finally, a chemical mechanical polishing process is performed, such that the surfaces of the dielectric layer 141 become flat and smooth, thereby forming the first extraction electrode 14201 and the second extraction electrode 14202.
Alternatively, after the electroplating process, the thickened metal films 1420a on the first surface and the second surface may be patterned, to form the first extraction electrode 14201 and the second extraction electrode 14202.
S151, preparing a dielectric layer 151, wherein a material of the dielectric layer 151 includes, but is not limited to, any one of glass, Si, SOI, GaAs, SiC, InP, PCB, Al2O3; forming a connection via 151a through a laser drilling process on the dielectric layer 151.
In some examples, step S151 may specifically include: vertically irradiating a laser onto a surface (a first surface or a second surface) of the dielectric layer 151 by means of a laser device. When the laser interacts with the dielectric layer 151, atoms forming the dielectric layer 151 are ionized and projected out of the surface of the dielectric layer 151 due to higher photon energy of the laser, and the drilled via is gradually deepened along with time, until the whole dielectric layer 151 is penetrated. That is, the connection via 151a is formed. An inclination angle of the connection via 151a is approximately in a range of 0° to 5°. For example, the inclination angle of the connection via 151a is 5. That is, the connection via 151a has a shape like a cylinder or a truncated cone, an inverted truncated cone. Generally, the laser has a wavelength selected from 532 nm, 355 nm, 266 nm, 248 nm, 197 nm or the like, the laser may have a pulse width selected from 1 fs to 100 fs, 1 ps to 100 ps, 1 ns to 100 ns or the like, and a type of the laser device may be selected from a continuous laser device, a pulse laser device or the like. The laser drilling includes the following two modes: when a diameter of a light spot is large, a relative position between a laser beam and the dielectric layer 151 is fixed, the dielectric layer 151 is directly penetrated by means of the high energy, such that a shape of the connection via 151a is the inverted truncated cone, and diameters of the connection via are gradually reduced from top to bottom (along a propagation direction of the laser). The diameter of the connection via 151a on the second surface is in a range of about 80 um to about 120 um, and the diameter of the connection via 151a on the first surface is in a range of about 60 um to about 100 um. The other mode of the laser drilling is: when the diameter of the light spot is small, the laser beam moves (scans) in circles on the dielectric layer 151. Specifically, a focal point of the light spot is constantly changed, a depth of the focal point is constantly changed, the laser beam moves in a spiral line from a lower surface of the dielectric layer 151 to an upper surface of the dielectric layer 151, and radiuses of the spiral line are gradually reduced from the lower surface to the upper surface. In this way, a portion of the dielectric layer 151 is obtained through the laser cut and is truncated cone shaped, and falls down due to the gravity, thereby forming the connection via 151a which is truncated cone shaped. The diameter of the connection via 151a on the second surface is in a range of about 100 um to about 1000 um, and the diameter of the connection via 151a on the first surface is in a range of about 150 um to about 1500 um.
S152, cleaning the dielectric layer 151, after step S151, so that residues, debris (151b shown in
In some examples, step S152 may specifically include: placing the dielectric layer 151 into a water tank containing pure deionized water or a combination of the deionized water with a proper amount of cleaning agent (such as an oil-based cleaning agent or a water-based cleaning agent) at a temperature approximately in a range of 35° C. to 70° C., wherein the water is subjected to cavitation, acceleration and direct flow actions by means of ultrasonic waves (with a frequency approximately in a range of 10 kHz to 10 MHz), so that a pollutant layer is dispersed, emulsified and stripped to achieve the purpose of cleaning, wherein the cleaning time is approximately in a range of 2 to 20 minutes; and finally, washing the dielectric layer 151 by using the pure deionized water, and taking the dielectric layer 151 out of the water tank, and drying the dielectric layer 151 by using an air knife.
S153, after the step S152, applying a metal paste 1520 into the connection via 151a of the dielectric layer 151, and forming the metal paste 1520 on the first surface and the second surface of the dielectric layer 151; and then, curing the metal paste 1520 on the first surface and the second surface, respectively, to form a connection electrode 15203 filled in the connection via 151a, a first extraction electrode 15201 on the first surface and a second extraction electrode 15202 on the second surface.
In some examples, the metal paste 1520 may be a conductive paste. A material of the conductive paste includes, but is not limited to, a low-temperature curing type polymer conductive paste, and main components of the conductive paste include conductive particles, a resin, a curing agent, a dispersant, a diluent, an adhesion enhancer, and an anti-settling agent. The conductive particles may be selected from Cu, Ag and Au, and a size of each particle is approximately in a range of 1 nm to 100 um. The resin may be bisphenol epoxy resin. The curing agent may be acid anhydrides. The dispersant may be methylimidazole. The diluent may be butyl acetate. The adhesion enhancer may be tetraethyl titanate. The anti-settling agent may be polyamides.
Step S153 may specifically include: firstly, coating the conductive paste in the connection via 151a and around an edge of the connection via 151a on the second surface, and then, performing solvent drying and thermocuring processes on the second surface of the dielectric layer 151 to form the connection electrode 15203 filled in the connection via 151a and the second extraction electrode 15202 located on the second surface; then, coating the conductive paste around an edge of the connection via 151a on the first surface of the dielectric layer 151, and then, performing solvent drying and thermocuring processes on the first surface of the dielectric layer 151 to form the first extraction electrode 15201 located on the first surface. The preferred mode for coating the conductive paste includes, but is not limited to, screen printing, ink-jet printing, slit coating or the like. A vacuum adsorption machine is used in cooperation when the conductive paste is coated, so that the coating efficiency may be improved, and a distribution profile of the conductive paste on the wall and the edge of the connection via may be improved. The solvent drying process may be performed under an atmospheric pressure of air, an atmospheric pressure of N2 or the vacuum, at a temperature in a range of about 40° C. to about 95° C., for a duration in a range of about 1 min to about 30 min. The thermocuring process may be performed in an oven, under the atmosphere of N2, at a heating temperature in a range of about 140° C. to about 200° C. Alternatively, the curing process may be performed by means of illumination with laser beams, which have a wavelength in a range of about 500 nm to about 1510 nm, a laser power in a range of 50 mW to 50 W, and a beam diameter in a range of about 10 um to about 2000 um, and the laser beams may be a single beam or multiple beams.
S161, preparing a dielectric layer 161, wherein a material of the dielectric layer 161 includes, but is not limited to, any one of glass, Si, SOI; forming a connection via 161a through a laser drilling process on the dielectric layer 161.
In some examples, step S161 may specifically include: vertically irradiating a laser onto a surface (a first surface or a second surface) of the dielectric layer 161 by means of a laser device. When the laser interacts with the dielectric layer 161, atoms forming the dielectric layer 161 are ionized and projected out of the surface of the dielectric layer 161 due to higher photon energy of the laser, and the drilled via is gradually deepened along with time, until the whole dielectric layer 161 is penetrated. That is, the connection via 161a is formed. An inclination angle of the connection via 161a is approximately in a range of 0° to 5°. For example, the inclination angle of the connection via 161a is 5°. That is, the connection via 161a has a shape like a cylinder or a truncated cone, an inverted truncated cone. Generally, the laser has a wavelength selected from 532 nm, 355 nm, 266 nm, 248 nm, 197 nm or the like, the laser may have a pulse width selected from 1 fs to 100 fs, 1 ps to 100 ps, 1 ns to 100 ns or the like, and a type of the laser device may be selected from a continuous laser device, a pulse laser device or the like. The laser drilling includes the following two modes: when a diameter of a light spot is large, a relative position between a laser beam and the dielectric layer 161 is fixed, the dielectric layer 161 is directly penetrated by means of the high energy, such that a shape of the connection via 161a is the inverted truncated cone, and diameters of the connection via are gradually reduced from top to bottom (along a propagation direction of the laser). The diameter of the connection via 161a on the second surface is in a range of about 80 um to about 120 um, and the diameter of the connection via 161a on the first surface is in a range of about 60 um to about 100 um. The other mode of the laser drilling is: when the diameter of the light spot is small, the laser beam moves (scans) in circles on the dielectric layer 161. Specifically, a focal point of the light spot is constantly changed, a depth of the focal point is constantly changed, the laser beam moves in a spiral line from a lower surface of the dielectric layer 161 to an upper surface of the dielectric layer 161, and radiuses of the spiral line are gradually reduced from the lower surface to the upper surface. In this way, a portion of the dielectric layer 161 is obtained through the laser cut and is truncated cone shaped, and falls down due to the gravity, thereby forming the connection via 161a which is truncated cone shaped. The diameter of the connection via 161a on the second surface is in a range of about 100 um to about 1000 um, and the diameter of the connection via 161a on the first surface is in a range of about 150 um to about 1500 um.
S162, cleaning the dielectric layer 161, after step S161, so that residues, debris (161b shown in
In some examples, step S162 may specifically include: the dielectric layer 161 is placed into a water tank, wherein the dielectric layer 161 is firstly subjected to ultrasonic cleaning to remove floating dust on a surface of the dielectric layer; the dielectric layer 161 is then immersed in a solution containing hydrofluoric acid for chemical corrosion, so that defects, such as microcrack areas Q1, stress concentration areas Q2 and the like, which are near the connection via 161a and in its inner wall on the dielectric layer 161 made of glass, Si or SO, may be thoroughly removed through the chemical corrosion. A content of HF in the solution is approximately in a range of 1% to 20%, and NH4F may or may not be contained in the solution. When NH4F is contained, a content of NH4F is approximately in a range of 10 to 40%, a temperature of the solution is approximately in a range of 35° C. to 60° C., a duration for the chemical corrosion is approximately in a range of 30 seconds to 5 minutes. Then, the dielectric layer 161 is thoroughly washed by the pure deionized water, and finally, is dried by the air knife. The chemically corroded connection via 161a has smooth inner wall and surface and does not contain the defects, such as microcrack areas Q1, stress concentration areas Q2 and the like, which is beneficial to the growth of seed layers with a high quality, the via-filling and the thickening with metal.
S163, after the step S162, applying a metal paste into the connection via 161a of the dielectric layer 161, and forming the metal paste on the first surface and the second surface of the dielectric layer 161; and then, curing the metal paste on the first surface and the second surface, respectively, to form a connection electrode 16203 filled in the connection via 161a, a first extraction electrode 16201 on the first surface and a second extraction electrode 16202 on the second surface.
In some examples, the metal paste may be a conductive paste. A material of the conductive paste includes, but is not limited to, a low-temperature curing type polymer conductive paste, and main components of the conductive paste include conductive particles, a resin, a curing agent, a dispersant, a diluent, an adhesion enhancer, and an anti-settling agent. The conductive particles may be selected from Cu, Ag and Au, and a size of each particle is approximately in a range of 1 nm to 100 um. The resin may be bisphenol epoxy resin. The curing agent may be acid anhydrides. The dispersant may be methylimidazole. The diluent may be butyl acetate. The adhesion enhancer may be tetraethyl titanate. The anti-settling agent may be polyamides.
Step S163 may specifically include: firstly, coating the conductive paste in the connection via 161a and around an edge of the connection via 161a on the second surface, and then, performing solvent drying and thermocuring processes on the second surface of the dielectric layer 161 to form the connection electrode 16203 filled in the connection via 161a and the second extraction electrode 16202 located on the second surface; then, coating the conductive paste around an edge of the connection via 161a on the first surface of the dielectric layer 161, and then, performing solvent drying and thermocuring processes on the first surface of the dielectric layer 161 to form the first extraction electrode 16201 located on the first surface. The preferred mode for coating the conductive paste includes, but is not limited to, screen printing, ink-jet printing, slit coating or the like. A vacuum adsorption machine is used in cooperation when the conductive paste is coated, so that the coating efficiency may be improved, and a distribution profile of the conductive paste on the wall and the edge of the connection via may be improved. The solvent drying process may be performed under an atmospheric pressure of air, an atmospheric pressure of N2 or the vacuum, at a temperature in a range of about 40° C. to about 95° C., for a duration in a range of about 1 min to about 30 min. The thermocuring process may be performed in an oven, under the atmosphere of N2, at a heating temperature in a range of about 140° C. to about 200° C. Alternatively, the curing process may be performed by means of illumination with laser beams, which have a wavelength in a range of about 500 nm to about 1510 nm, a laser power in a range of 50 mW to 50 W, and a beam diameter in a range of about 10 um to about 2000 um, and the laser beams may be a single beam or multiple beams.
S171, preparing a dielectric layer 171, wherein a material of the dielectric layer 171 includes, but is not limited to, any one of glass, Si, SOI, GaAs, SiC, InP, PCB, Al2O3; forming a connection via 171a through a laser drilling process on the dielectric layer 171.
In some examples, step S171 may specifically include: vertically irradiating a laser onto a surface (a first surface or a second surface) of the dielectric layer 171 by means of a laser device. When the laser interacts with the dielectric layer 171, atoms forming the dielectric layer 171 are ionized and projected out of the surface of the dielectric layer 171 due to higher photon energy of the laser, and the drilled via is gradually deepened along with time, until the whole dielectric layer 171 is penetrated. That is, the connection via 171a is formed. An inclination angle of the connection via 171a is approximately in a range of 0° to 5°. For example, the inclination angle of the connection via 171a is 5. That is, the connection via 171a has a shape like a cylinder or a truncated cone, an inverted truncated cone. Generally, the laser has a wavelength selected from 532 nm, 355 nm, 266 nm, 248 nm, 197 nm or the like, the laser may have a pulse width selected from 1 fs to 100 fs, 1 ps to 100 ps, 1 ns to 100 ns or the like, and a type of the laser device may be selected from a continuous laser device, a pulse laser device or the like. The laser drilling includes the following two modes: when a diameter of a light spot is large, a relative position between a laser beam and the dielectric layer 171 is fixed, the dielectric layer 171 is directly penetrated by means of the high energy, such that a shape of the connection via 171a is the inverted truncated cone, and diameters of the connection via are gradually reduced from top to bottom (along a propagation direction of the laser). The diameter of the connection via 171a on the second surface is in a range of about 80 um to about 120 um, and the diameter of the connection via 171a on the first surface is in a range of about 60 um to about 100 um. The other mode of the laser drilling is: when the diameter of the light spot is small, the laser beam moves (scans) in circles on the dielectric layer 171. Specifically, a focal point of the light spot is constantly changed, a depth of the focal point is constantly changed, the laser beam moves in a spiral line from a lower surface of the dielectric layer 171 to an upper surface of the dielectric layer 171, and radiuses of the spiral line are gradually reduced from the lower surface to the upper surface. In this way, a portion of the dielectric layer 171 is obtained through the laser cut and is truncated cone shaped, and falls down due to the gravity, thereby forming the connection via 171a which is truncated cone shaped. The diameter of the connection via 171a on the second surface is in a range of about 100 um to about 1000 um, and the diameter of the connection via 171a on the first surface is in a range of about 150 um to about 1500 um.
S172, cleaning the dielectric layer 171, after step S171, so that residues, debris (171b shown in
In some examples, step S172 may specifically include: placing the dielectric layer 171 into a water tank containing pure deionized water or a combination of the deionized water with a proper amount of cleaning agent (such as an oil-based cleaning agent or a water-based cleaning agent) at a temperature approximately in a range of 35° C. to 70° C., wherein the water is subjected to cavitation, acceleration and direct flow actions by means of ultrasonic waves (with a frequency approximately in a range of 10 kHz to 10 MHz), so that a pollutant layer is dispersed, emulsified and stripped to achieve the purpose of cleaning, wherein the cleaning time is approximately in a range of 2 to 20 minutes; and finally, washing the dielectric layer 171 by using the pure deionized water, and taking the dielectric layer 171 out of the water tank, and drying the dielectric layer 171 by using an air knife.
S173, forming a chemical plating medium 1720 on the first surface and the second surface of the dielectric layer 171 provided with the connection via 171a after the step S172.
In some examples, step S173 may specifically include: placing the dielectric layer 171, in a spraying mode or directly, into a water tank containing a solution of the chemical plating medium 1720, so that a layer of Sn2+ is adsorbed on surfaces of the dielectric layer 171. The solution of the chemical plating medium 1720 mainly contains SnCl2 of 10 g/L to 30 g/L, concentrated hydrochloric acid (having a concentration of 38%) of 20 ml/L to 60 ml/L and deionized water. A less number of Sn particles are added into the solution to prevent the Sn2+ from being oxidated. Then, the dielectric layer 171 is placed, in a spraying mode or directly, into a water tank containing an activation solution, so that surfaces of the dielectric layer 171 reacts with the activation solution (mainly containing SnCl2 of 80 g/L to 120 g/L, concentrated hydrochloric acid of 300 ml/L to 500 ml/L, Na2SnO3 of 10 g/L to 20 g/L, PdCl2 of 1 g/L to 4 g/L and deionized water), to generate metal palladium particles which are tightly attached to the surfaces of the dielectric layer 171. That is, the chemical plating medium 1720 is formed on the first surface and the second surface of the dielectric layer 171 provided with the connection via 171a.
S174, after the step S173, performing a chemical plating process on the dielectric layer 171 with the chemical plating medium 1720 to form metal films on the first surface, the second surface of the dielectric layer 171, and in the connection via 171a, and patterning the metal films formed on the first surface and the second surface of the dielectric layer 171, for forming a first extraction electrode 17201 and a second extraction electrode 17202, and a connection electrode 17203 in the connection via 171a.
In some examples, the chemically plated metal films may be a single-layer metal film or may be metal films stacked together. For example: only a Cu metal film is plated to form a single-layer metal film (having a thickness in a range of about 1 um to about 100 um). Alternatively, it is also possible to firstly plate a Ni metal film (having a thickness in a range of about 10 um to about 100 um), and then a Cu metal film (having a thickness in a range of about 1 um to about 100 um), wherein the Ni metal film is used to increase the adhesion of the Cu metal film. In the embodiment of the present disclosure, as an example, a material of the single-layer metal film is Cu, and a material of metal films stacked together is Ni/Cu, which does not limit the scope of the embodiment of the present disclosure. It will be described below by taking an example in which Ni/Cu metal films are chemically plated.
In some examples, step S174 may specifically include: placing the dielectric layer 171 into the chemical plating solution, and sequentially performing the chemical plating process with metal Ni and Cu. Then, the metal films formed on the first surface and the second surface of the dielectric layer 171 are patterned, for forming the first extraction electrode 17201 and the second extraction electrode 17202, and the connection electrode 17203 in the connection via 171a. The Ni solution for the chemical plating generally contains NiSO4·6H2O of 10 g/L to 30 g/L, NaH2PO4·2H2O 20 g/L to 40 g/L, Na-Citrate of 5 g/L to 15 g/L and NH4Cl of 20 g/L to 40 g/L, the solution is alkaline, has a PH in a range of 8.0 to 10.0 and a temperature in a range of 75° C. to 90° C. The Cu solution for the chemical plating generally contains KNaC4H4O6 of 30 g/L to 50 g/L, NaOH of 8 g/L to 10 g/L, Na2CO3 of 38 g/L to 40 g/L, CuSO4 of 10 g/L to 20 g/L, NiCl2 of 2 g/L to 6 g/L and formaldehyde of 40 ml/L to 60 ml/L with a concentration of 35%, the solution is alkaline, has a PH in a range of 11.0 to 14.0 and a temperature in a range of 55° C. to 65° C.
S181, preparing a dielectric layer 181, wherein a material of the dielectric layer 181 includes, but is not limited to, any one of glass, Si, SOI; forming a connection via 181a through a laser drilling process on the dielectric layer 181.
In some examples, step S181 may specifically include: vertically irradiating a laser onto a surface (a first surface or a second surface) of the dielectric layer 181 by means of a laser device. When the laser interacts with the dielectric layer 181, atoms forming the dielectric layer 181 are ionized and projected out of the surface of the dielectric layer 181 due to higher photon energy of the laser, and the drilled via is gradually deepened along with time, until the whole dielectric layer 181 is penetrated. That is, the connection via 181a is formed. An inclination angle of the connection via 181a is approximately in a range of 0° to 5°. For example, the inclination angle of the connection via 181a is 5°. That is, the connection via 181a has a shape like a cylinder or a truncated cone, an inverted truncated cone. Generally, the laser has a wavelength selected from 532 nm, 355 nm, 266 nm, 248 nm, 197 nm or the like, the laser may have a pulse width selected from 1 fs to 100 fs, 1 ps to 100 ps, 1 ns to 100 ns or the like, and a type of the laser device may be selected from a continuous laser device, a pulse laser device or the like. The laser drilling includes the following two modes: when a diameter of a light spot is large, a relative position between a laser beam and the dielectric layer 181 is fixed, the dielectric layer 181 is directly penetrated by means of the high energy, such that a shape of the connection via 181a is the inverted truncated cone, and diameters of the connection via are gradually reduced from top to bottom (along a propagation direction of the laser). The diameter of the connection via 181a on the second surface is in a range of about 80 um to about 120 um, and the diameter of the connection via 181a on the first surface is in a range of about 60 um to about 100 um. The other mode of the laser drilling is: when the diameter of the light spot is small, the laser beam moves (scans) in circles on the dielectric layer 181. Specifically, a focal point of the light spot is constantly changed, a depth of the focal point is constantly changed, the laser beam moves in a spiral line from a lower surface of the dielectric layer 181 to an upper surface of the dielectric layer 181, and radiuses of the spiral line are gradually reduced from the lower surface to the upper surface. In this way, a portion of the dielectric layer 181 is obtained through the laser cut and is truncated cone shaped, and falls down due to the gravity, thereby forming the connection via 181a which is truncated cone shaped. The diameter of the connection via 181a on the second surface is in a range of about 100 um to about 1000 um, and the diameter of the connection via 181a on the first surface is in a range of about 150 um to about 1500 um.
S182, cleaning the dielectric layer 181, after step S181, so that residues, debris (181b shown in
In some examples, step S182 may specifically include: the dielectric layer 181 is placed into a water tank, wherein the dielectric layer 181 is firstly subjected to ultrasonic cleaning to remove floating dust on a surface of the dielectric layer; the dielectric layer 181 is then immersed in a solution containing hydrofluoric acid for chemical corrosion, so that defects, such as microcrack areas Q1, stress concentration areas Q2 and the like, which are near the connection via 181a and in its inner wall on the dielectric layer 181 made of glass, Si or SO, may be thoroughly removed through the chemical corrosion. A content of HF in the solution is approximately in a range of 1% to 20%, and NH4F may or may not be contained in the solution. When NH4F is contained, a content of NH4F is approximately in a range of 10 to 40%, a temperature of the solution is approximately in a range of 35° C. to 60° C., a duration for the chemical corrosion is approximately in a range of 30 seconds to 5 minutes. Then, the dielectric layer 181 is thoroughly washed by the pure deionized water, and finally, is dried by the air knife. The chemically corroded connection via 181a has smooth inner wall and surface and does not contain the defects, such as microcrack areas Q1, stress concentration areas Q2 and the like, which is beneficial to the growth of seed layers with a high quality, the via-filling and the thickening with metal.
S183, forming a chemical plating medium on the first surface and the second surface of the dielectric layer 181 provided with the connection via 181a after the step S182.
In some examples, step S183 may specifically include: placing the dielectric layer 181, in a spraying mode or directly, into a water tank containing a solution of the chemical plating medium, so that a layer of Sn2+ is adsorbed on surfaces of the dielectric layer 181. The solution of the chemical plating medium mainly contains SnCl2 of 10 g/L to 30 g/L, concentrated hydrochloric acid (having a concentration of 38%) of 20 ml/L to 60 ml/L and deionized water. A less number of Sn particles are added into the solution to prevent the Sn2+ from being oxidated. Then, the dielectric layer 181 is placed, in a spraying mode or directly, into a water tank containing an activation solution, so that surfaces of the dielectric layer 121 reacts with the activation solution (mainly containing SnCl2 of 80 g/L to 120 g/L, concentrated hydrochloric acid of 300 ml/L to 500 ml/L, Na2SnO3 of 10 g/L to 20 g/L, PdCl2 of 1 g/L to 4 g/L and deionized water), to generate metal palladium particles which are tightly attached to the surfaces of the dielectric layer 181. That is, the chemical plating medium is formed on the first surface and the second surface of the dielectric layer 181 provided with the connection via 181a.
S184, after the step S183, performing a chemical plating process on the dielectric layer 181 with the chemical plating medium to form metal films on the first surface, the second surface of the dielectric layer 181, and in the connection via 181a, and patterning the metal films formed on the first surface and the second surface of the dielectric layer 181, for forming a first extraction electrode 18201 and a second extraction electrode 18202, and a connection electrode 18203 in the connection via 181a.
In some examples, the chemically plated metal films may be a single-layer metal film or may be metal films stacked together. For example: only a Cu metal film is plated to form a single-layer metal film (having a thickness in a range of about 1 um to about 100 um). Alternatively, it is also possible to firstly plate a Ni metal film (having a thickness in a range of about 10 um to about 100 um), and then a Cu metal film (having a thickness in a range of about 1 um to about 100 um), wherein the Ni metal film is used to increase the adhesion of the Cu metal film. In the embodiment of the present disclosure, as an example, a material of the single-layer metal film is Cu, and a material of metal films stacked together is Ni/Cu, which does not limit the scope of the embodiment of the present disclosure. It will be described below by taking an example in which Ni/Cu metal films are chemically plated.
In some examples, step S184 may specifically include: placing the dielectric layer 181 into the chemical plating solution, and sequentially performing the chemical plating process with metal Ni and Cu. Then, the metal films formed on the first surface and the second surface of the dielectric layer 181 are patterned, for forming the first extraction electrode 18201 and the second extraction electrode 18202, and the connection electrode 18203 in the connection via 181a. The Ni solution for the chemical plating generally contains NiSO4·6H2O of 10 g/L to 30 g/L, NaH2PO4·2H2O 20 g/L to 40 g/L, Na-Citrate of 5 g/L to 15 g/L and NH4Cl of 20 g/L to 40 g/L, the solution is alkaline, has a PH in a range of 8.0 to 10.0 and a temperature in a range of 75° C. to 90° C.
The Cu solution for the chemical plating generally contains KNaC4H406 of 30 g/L to 50 g/L, NaOH of 8 g/L to 10 g/L, Na2CO3 of 38 g/L to 40 g/L, CuSO4 of 10 g/L to 20 g/L, NiCl2 of 2 g/L to 6 g/L and formaldehyde of 40 ml/L to 60 ml/L with a concentration of 35%, the solution is alkaline, has a PH in a range of 11.0 to 14.0 and a temperature in a range of 55° C. to 65° C.
S191, preparing a dielectric layer 191; and forming a connection via 191a extending through the dielectric layer 191 through a patterning process.
In some examples, step S191 may specifically include: forming the connection via 191a in the dielectric layer 191 through an etching process. The etching process includes two types of etching processes, that is, a wet etching process and a dry etching process. The connection via 191a may be formed in the dielectric layer 191 by reasonably selecting the type of the etching process, a formula of etching liquid or a proportion of etching gas, an etching duration, a temperature and the like. It will be described below that the connection via 191a extending through the dielectric layer 191 is formed through the wet etching process and the dry etching process, respectively.
In one example, for a silicon substrate with a crystal orientation (100) as the dielectric layer 191, firstly, a mask layer 100 is formed on a first surface of the dielectric layer 191 through a photolithographic process. For example, the mask layer 100 is formed of a photoresist or a silicon dioxide film. The dielectric layer 191 is placed into a tetramethyl ammonium hydroxide aqueous solution at a temperature of 90° C. for the wet etching. A depth of the via increases with time, until the dielectric layer 191 is penetrated. The mask layer 100 is removed. That is, the connection via 191a is formed. An inclination angle of the connection via 191a is in a range of about 0° to about 45°. For example, the inclination angle of the connection via 191a is 15°. When the mask layer 100 is made of the photoresist, the photoresist is cleaned with acetone by means of ultrasonic waves such that the photoresist is removed. When the mask layer 100 is made of the silicon dioxide film, the silicon dioxide film is etched away with diluted hydrofluoric acid. In addition, if the dielectric layer 191 is made of the glass, the wet etching process is at a temperature of 25° C., wherein a ratio of 40% NF4F solution to 49% HF solution is in a range of 4.8:1 to 5.2:1.
In another example, for a silicon substrate with a crystal orientation (100) as the dielectric layer 191, firstly, a mask layer 100 is formed on a first surface of the dielectric layer 191 through a photolithographic process. For example, the mask layer 100 is formed of a photoresist or a silicon dioxide film. The dielectric layer 191 is placed into a vacuum chamber of a reactive ion etching device or an inductively coupled plasma etching device for the dry etching, wherein a gas pressure is in a range of 40 Pa to 60 Pa and a ratio of Cl2 gas to He gas is in a range of 3:10 to 6:10, and the dielectric layer 191 is heated to 40° C. A depth of the via increases with time, until the dielectric layer 191 is penetrated. The mask layer 100 is removed. That is, the connection via 191a is formed. An inclination angle of the connection via 191a is in a range of about 0° to about 5°. For example, the inclination angle of the connection via 191a is 5°. When the mask layer 100 is made of the photoresist, the photoresist is cleaned with acetone by means of ultrasonic waves such that the photoresist is removed. When the mask layer 100 is made of the silicon dioxide film, the silicon dioxide film is etched away with diluted hydrofluoric acid. In addition, if the dielectric layer 191 is made of the glass, the dry etching process is at a temperature of 25° C. and at a gas pressure in a range of 250 Pa to 450 Pa, wherein a proportion of CF4 is in a range of 80 to 100, a proportion of CHF3 is in a range of 25 to 35 and a proportion of He is in a range of 110 to 130.
S192, cleaning the dielectric layer 191, after step S191, so that residues, debris, and the like near the inner wall and an outer edge of the connection via 191a are washed away.
In some examples, step S192 may specifically include: placing the dielectric layer 191 into a water tank containing pure deionized water or a combination of the deionized water with a proper amount of cleaning agent (such as an oil-based cleaning agent or a water-based cleaning agent) at a temperature approximately in a range of 35° C. to 70° C., wherein the water is subjected to cavitation, acceleration and direct flow actions by means of ultrasonic waves (with a frequency approximately in a range of 10 kHz to 10 MHz), so that a pollutant layer is dispersed, emulsified and stripped to achieve the purpose of cleaning, wherein the cleaning time is approximately in a range of 2 to 20 minutes; and finally, washing the dielectric layer 191 by using the pure deionized water, and taking the dielectric layer 191 out of the water tank, and drying the dielectric layer 191 by using an air knife.
S193, forming metal films, as seed layers, within the connection via of the dielectric layer 191, and on the first surface and the second surface of the dielectric layer 191, after the step S192.
In some examples, step S193 may specifically include: depositing metal films with good conductivity, as seed layers, on the whole first surface and the whole second surface of the dielectric layer 191 through a process including, but being not limited to, a magnetron sputtering process. In addition to the magnetron sputtering process, the metal films may be formed through an electron beam evaporation process, an thermal evaporation process, or a pulsed laser sputtering process.
In some examples, a metal stack is generally used to increase the adhesion between the metal films and the dielectric layer 191. That is, the metal films include a first metal sub-layer and a second metal sub-layer sequentially arranged in a direction away from the dielectric layer 191. A material of the first metal sub-layer includes, but is not limited to, any one of titanium (Ti), molybdenum (Mo), and nickel (Ni), and a material of the second metal sub-layer includes, but is not limited to, any one of copper (Cu), silver (Ag), or gold (Au). For example, the metal films include: any one of Ti/Cu, Mo/Cu, Ni/Cu, Ti/Ag, MWAg and Ni/Ag. In the embodiment of the present disclosure, a thickness of the first metal sub-layer is in a range of about 1 nm to about 100 nm; a thickness of the second metal sub-layer is in a range of about 50 nm to about 1000 nm. In addition, a thickness of the metal film on the inner wall of the connection via 191a is in a range of about 1 nm to about 200 nm.
S194, filling the connection via 191a through an electroplating process and thickening the metal films 1920 formed on the first surface and the second surface, after the step S193, to form a first extraction electrode 19201 on the first surface and a second extraction electrode 19202 on the second surface, respectively, and a connection electrode 19203 within the connection via 191a.
In some examples, step S194 may specifically include: firstly, a via-filling electroplating process is performed in an electroplating bath through a reasonable combination of different types of electroplating solutions (such as a formula for filling the metal film into the connection via 191a and a formula for thickening the metal films on the whole surfaces), so that the metal film 1920 (such as a first metal sub-layer in the metal film 1920) is deposited on the inner wall of the connection via 191a, wherein an electroplating rate is in a range of 0.5 um/min to 5 um/min, and depending to an electroplating duration, the metal material may fully fill the connection via 191a (a thickness of the metal film is equal to 0.5 times of a diameter of the connection via 191a) or not fully fill the connection via 191a, only the inner wall of the connection via 191a is metallized (the thickness of the metal film is in a range of 500 nm to 10 um). That is, the connection electrode 19203 is formed. Then, the dielectric layer 191 is moved into the electroplating bath for the formula for thickening the metal films on the whole surfaces, to thicken the metal films 1920 on the first surface and the second surface through an electroplating process, respectively, wherein the electroplating metal is Cu, Ag or Au, the electroplating rate is in a range of 0.5 um/min to 5 um/min, and depending to the electroplating duration, a thickness of each of the thickened metal films 1920a is approximately in a range of 500 nm to 500 um. After the electroplating process, the surfaces of the dielectric layer 191 are generally undulated and uneven, which adversely affects subsequent processes. Thus, finally, a chemical mechanical polishing process is performed, such that the surfaces of the dielectric layer 191 become flat and smooth, thereby forming the first extraction electrode 19201 and the second extraction electrode 19202.
Alternatively, after the electroplating process, the thickened metal films 1920a on the first surface and the second surface may be patterned, to form the first extraction electrode 19201 and the second extraction electrode 19202.
S201, preparing a dielectric layer 201; and forming a connection via 201a extending through the dielectric layer 201 through a patterning process.
In some examples, step S201 may specifically include: forming the connection via 201a in the dielectric layer 201 through an etching process. The etching process includes two types of etching processes, that is, a wet etching process and a dry etching process. The connection via 201a may be formed in the dielectric layer 201 by reasonably selecting the type of the etching process, a formula of etching liquid or a proportion of etching gas, an etching duration, a temperature and the like. It will be described below that the connection via 201a extending through the dielectric layer 201 is formed through the wet etching process and the dry etching process, respectively.
In one example, for a silicon substrate with a crystal orientation (100) as the dielectric layer 201, firstly, a mask layer 100 is formed on a first surface of the dielectric layer 201 through a photolithographic process. For example, the mask layer 100 is formed of a photoresist or a silicon dioxide film. The dielectric layer 201 is placed into a tetramethyl ammonium hydroxide aqueous solution at a temperature of 90° C. for the wet etching. A depth of the via increases with time, until the dielectric layer 201 is penetrated. The mask layer 100 is removed. That is, the connection via 201a is formed. An inclination angle of the connection via 201a is in a range of about 0° to about 45°. For example, the inclination angle of the connection via 201a is 15°. When the mask layer 100 is made of the photoresist, the photoresist is cleaned with acetone by means of ultrasonic waves such that the photoresist is removed. When the mask layer 100 is made of the silicon dioxide film, the silicon dioxide film is etched away with diluted hydrofluoric acid. In addition, if the dielectric layer 201 is made of the glass, the wet etching process is at a temperature of 25° C., wherein a ratio of 40% NF4F solution to 49% HF solution is in a range of 4.8:1 to 5.2:1.
In another example, for a silicon substrate with a crystal orientation (100) as the dielectric layer 201, firstly, a mask layer 100 is formed on a first surface of the dielectric layer 201 through a photolithographic process. For example, the mask layer 100 is formed of a photoresist or a silicon dioxide film. The dielectric layer 201 is placed into a vacuum chamber of a reactive ion etching device or an inductively coupled plasma etching device for the dry etching, wherein a gas pressure is in a range of 40 Pa to 60 Pa and a ratio of Cl2 gas to He gas is in a range of 3:10 to 6:10, and the dielectric layer 201 is heated to 40° C. A depth of the via increases with time, until the dielectric layer 201 is penetrated. The mask layer 100 is removed. That is, the connection via 201a is formed. An inclination angle of the connection via 201a is in a range of about 0° to about 5°. For example, the inclination angle of the connection via 201a is 5°. When the mask layer 100 is made of the photoresist, the photoresist is cleaned with acetone by means of ultrasonic waves such that the photoresist is removed. When the mask layer 100 is made of the silicon dioxide film, the silicon dioxide film is etched away with diluted hydrofluoric acid. In addition, if the dielectric layer 201 is made of the glass, the dry etching process is at a temperature of 25° C. and at a gas pressure in a range of 250 Pa to 450 Pa, wherein a proportion of CF4 is in a range of 80 to 100, a proportion of CHF3 is in a range of 25 to 35 and a proportion of He is in a range of 110 to 130.
S202, cleaning the dielectric layer 201, after step S201, so that residues, debris (201b shown in
In some examples, step S202 may specifically include: the dielectric layer 201 is placed into a water tank, wherein the dielectric layer 201 is firstly subjected to ultrasonic cleaning to remove floating dust on a surface of the dielectric layer, the dielectric layer 201 is then immersed in a solution containing hydrofluoric acid for chemical corrosion, so that defects, such as microcrack areas Q1, stress concentration areas Q2 and the like, which are near the connection via 201a and in its inner wall on the dielectric layer 201 made of glass, Si or SO, may be thoroughly removed through the chemical corrosion. A content of HF in the solution is approximately in a range of 1% to 20%, and NH4F may or may not be contained in the solution. When NH4F is contained, a content of NH4F is approximately in a range of 10 to 40%, a temperature of the solution is approximately in a range of 35° C. to 60° C., a duration for the chemical corrosion is approximately in a range of 30 seconds to 5 minutes. Then, the dielectric layer 201 is thoroughly washed by the pure deionized water, and finally, is dried by the air knife. The chemically corroded connection via 201a has smooth inner wall and surface and does not contain the defects, such as microcrack areas Q1, stress concentration areas Q2 and the like, which is beneficial to the growth of seed layers with a high quality, the via-filling and the thickening with metal.
S203, forming metal films 2020, as seed layers, within the connection via 201a of the dielectric layer 201, and on the first surface and the second surface of the dielectric layer 201, after the step S202.
In some examples, step S203 may specifically include: depositing metal films 2020 with good conductivity, as seed layers, on the whole first surface and the whole second surface of the dielectric layer 201 through a process including, but being not limited to, a magnetron sputtering process. In addition to the magnetron sputtering process, the metal films 2020 may be formed through an electron beam evaporation process, an thermal evaporation process, or a pulsed laser sputtering process.
In some examples, a metal stack is generally used to increase the adhesion between the metal films and the dielectric layer 201. That is, the metal films include a first metal sub-layer and a second metal sub-layer sequentially arranged in a direction away from the dielectric layer 201. A material of the first metal sub-layer includes, but is not limited to, any one of titanium (Ti), molybdenum (Mo), and nickel (Ni), and a material of the second metal sub-layer includes, but is not limited to, any one of copper (Cu), silver (Ag), or gold (Au). For example, the metal films include: any one of Ti/Cu, Mo/Cu, Ni/Cu, Ti/Ag, Mo/Ag and Ni/Ag. In the embodiment of the present disclosure, a thickness of the first metal sub-layer is in a range of about 1 nm to about 100 nm; a thickness of the second metal sub-layer is in a range of about 50 nm to about 1000 nm. In addition, a thickness of the metal film on the inner wall of the connection via 201a is in a range of about 1 nm to about 200 nm.
S204, filling the connection via 201a through an electroplating process and thickening the metal films 2020 formed on the first surface and the second surface, after the step S203, to form a first extraction electrode 20201 on the first surface and a second extraction electrode 20202 on the second surface, respectively, and a connection electrode 20203 within the connection via 201a.
In some examples, step S204 may specifically include: firstly, a via-filling electroplating process is performed in an electroplating bath through a reasonable combination of different types of electroplating solutions (such as a formula for filling the metal film into the connection via 201a and a formula for thickening the metal films on the whole surfaces), so that the metal film 2020 (such as a first metal sub-layer in the metal film 2020) is deposited on the inner wall of the connection via 201a, wherein an electroplating rate is in a range of 0.5 um/min to 5 um/min, and depending to an electroplating duration, the metal material may fully fill the connection via 201a (a thickness of the metal film is equal to 0.5 times of a diameter of the connection via 201a) or not fully fill the connection via 201a, only the inner wall of the connection via 201a is metallized (the thickness of the metal film is in a range of 500 nm to 10 um). That is, the connection electrode 20203 is formed. Then, the dielectric layer 201 is moved into the electroplating bath for the formula for thickening the metal films on the whole surfaces, to thicken the metal films 2020 on the first surface and the second surface through an electroplating process, respectively, wherein the electroplating metal is Cu, Ag or Au, the electroplating rate is in a range of 0.5 um/min to 5 um/min, and depending to the electroplating duration, a thickness of each of the thickened metal films 2020a is approximately in a range of 500 nm to 500 um. After the electroplating process, the surfaces of the dielectric layer 201 are generally undulated and uneven, which adversely affects subsequent processes. Thus, finally, a chemical mechanical polishing process is performed, such that the surfaces of the dielectric layer 201 become flat and smooth, thereby forming the first extraction electrode 20201 and the second extraction electrode 20202.
Alternatively, after the electroplating process, the thickened metal films 2020a on the first surface and the second surface may be patterned, to form the first extraction electrode 20201 and the second extraction electrode 20202.
S211, preparing a dielectric layer 211; and forming a connection via 211a extending through the dielectric layer 211 through a patterning process.
In some examples, step S211 may specifically include: forming the connection via 211a in the dielectric layer 211 through an etching process. The etching process includes two types of etching processes, that is, a wet etching process and a dry etching process. The connection via 211a may be formed in the dielectric layer 211 by reasonably selecting the type of the etching process, a formula of etching liquid or a proportion of etching gas, an etching duration, a temperature and the like. It will be described below that the connection via 211a extending through the dielectric layer 211 is formed through the wet etching process and the dry etching process, respectively.
In one example, for a silicon substrate with a crystal orientation (100) as the dielectric layer 211, firstly, a mask layer 100 is formed on a first surface of the dielectric layer 211 through a photolithographic process. For example, the mask layer 100 is formed of a photoresist or a silicon dioxide film. The dielectric layer 211 is placed into a tetramethyl ammonium hydroxide aqueous solution at a temperature of 90° C. for the wet etching. A depth of the via increases with time, until the dielectric layer 211 is penetrated. The mask layer 100 is removed. That is, the connection via 211a is formed. An inclination angle of the connection via 211a is in a range of about 0° to about 45°. For example, the inclination angle of the connection via 211a is 15°. When the mask layer 100 is made of the photoresist, the photoresist is cleaned with acetone by means of ultrasonic waves such that the photoresist is removed. When the mask layer 100 is made of the silicon dioxide film, the silicon dioxide film is etched away with diluted hydrofluoric acid. In addition, if the dielectric layer 211 is made of the glass, the wet etching process is at a temperature of 25° C., wherein a ratio of 40% NF4F solution to 49% HF solution is in a range of 4.8:1 to 5.2:1.
In another example, for a silicon substrate with a crystal orientation (100) as the dielectric layer 211, firstly, a mask layer 100 is formed on a first surface of the dielectric layer 211 through a photolithographic process. For example, the mask layer 100 is formed of a photoresist or a silicon dioxide film. The dielectric layer 211 is placed into a vacuum chamber of a reactive ion etching device or an inductively coupled plasma etching device for the dry etching, wherein a gas pressure is in a range of 40 Pa to 60 Pa and a ratio of Cl2 gas to He gas is in a range of 3:10 to 6:10, and the dielectric layer 211 is heated to 40° C. A depth of the via increases with time, until the dielectric layer 211 is penetrated. The mask layer 100 is removed. That is, the connection via 211a is formed. An inclination angle of the connection via 211a is in a range of about 0° to about 5°. For example, the inclination angle of the connection via 211a is 5°. When the mask layer 100 is made of the photoresist, the photoresist is cleaned with acetone by means of ultrasonic waves such that the photoresist is removed. When the mask layer 100 is made of the silicon dioxide film, the silicon dioxide film is etched away with diluted hydrofluoric acid. In addition, if the dielectric layer 211 is made of the glass, the dry etching process is at a temperature of 25° C. and at a gas pressure in a range of 250 Pa to 450 Pa, wherein a proportion of CF4 is in a range of 80 to 100, a proportion of CHF3 is in a range of 25 to 35 and a proportion of He is in a range of 110 to 130.
S212, cleaning the dielectric layer 211, after step S211, so that residues, debris (211b shown in
In some examples, step S212 may specifically include: placing the dielectric layer 211 into a water tank containing pure deionized water or a combination of the deionized water with a proper amount of cleaning agent (such as an oil-based cleaning agent or a water-based cleaning agent) at a temperature approximately in a range of 35° C. to 70° C., wherein the water is subjected to cavitation, acceleration and direct flow actions by means of ultrasonic waves (with a frequency approximately in a range of 10 kHz to 10 MHz), so that a pollutant layer is dispersed, emulsified and stripped to achieve the purpose of cleaning, wherein the cleaning time is approximately in a range of 2 to 20 minutes; and finally, washing the dielectric layer 211 by using the pure deionized water, and taking the dielectric layer 211 out of the water tank, and drying the dielectric layer 211 by using an air knife.
S213, after the step S212, applying a metal paste 2120 into the connection via 211a of the dielectric layer 211, and forming the metal paste 2120 on the first surface and the second surface of the dielectric layer 211; and then, curing the metal paste 2120 on the first surface and the second surface, respectively, to form a connection electrode 21203 filled in the connection via 211a, a first extraction electrode 21201 on the first surface and a second extraction electrode 21202 on the second surface.
In some examples, the metal paste 2120 may be a conductive paste. A material of the conductive paste includes, but is not limited to, a low-temperature curing type polymer conductive paste, and main components of the conductive paste include conductive particles, a resin, a curing agent, a dispersant, a diluent, an adhesion enhancer, and an anti-settling agent. The conductive particles may be selected from Cu, Ag and Au, and a size of each particle is approximately in a range of 1 nm to 100 um. The resin may be bisphenol epoxy resin. The curing agent may be acid anhydrides. The dispersant may be methylimidazole. The diluent may be butyl acetate. The adhesion enhancer may be tetraethyl titanate. The anti-settling agent may be polyamides.
Step S213 may specifically include: firstly, coating the conductive paste in the connection via 211a and around an edge of the connection via 211a on the second surface, and then, performing solvent drying and thermocuring processes on the second surface of the dielectric layer 211 to form the connection electrode 21203 filled in the connection via 211a and the second extraction electrode 21202 located on the second surface; then, coating the conductive paste around an edge of the connection via 211a on the first surface of the dielectric layer 211, and then, performing solvent drying and thermocuring processes on the first surface of the dielectric layer 211 to form the first extraction electrode 21201 located on the first surface. The preferred mode for coating the conductive paste includes, but is not limited to, screen printing, ink-jet printing, slit coating or the like. A vacuum adsorption machine is used in cooperation when the conductive paste is coated, so that the coating efficiency may be improved, and a distribution profile of the conductive paste on the wall and the edge of the connection via may be improved. The solvent drying process may be performed under an atmospheric pressure of air, an atmospheric pressure of N2 or the vacuum, at a temperature in a range of about 40° C. to about 95° C., for a duration in a range of about 1 min to about 30 min. The thermocuring process may be performed in an oven, under the atmosphere of N2, at a heating temperature in a range of about 140° C. to about 200° C. Alternatively, the curing process may be performed by means of illumination with laser beams, which have a wavelength in a range of about 500 nm to about 1510 nm, a laser power in a range of 50 mW to 50 W, and a beam diameter in a range of about 10 um to about 2000 um, and the laser beams may be a single beam or multiple beams.
S221, preparing a dielectric layer 221; and forming a connection via 221a extending through the dielectric layer 221 through a patterning process.
In some examples, step S221 may specifically include: forming the connection via 221a in the dielectric layer 221 through an etching process. The etching process includes two types of etching processes, that is, a wet etching process and a dry etching process. The connection via 221a may be formed in the dielectric layer 221 by reasonably selecting the type of the etching process, a formula of etching liquid or a proportion of etching gas, an etching duration, a temperature and the like. It will be described below that the connection via 221a extending through the dielectric layer 221 is formed through the wet etching process and the dry etching process, respectively.
In one example, for a silicon substrate with a crystal orientation (100) as the dielectric layer 221, firstly, a mask layer 100 is formed on a first surface of the dielectric layer 221 through a photolithographic process. For example, the mask layer 100 is formed of a photoresist or a silicon dioxide film. The dielectric layer 221 is placed into a tetramethyl ammonium hydroxide aqueous solution at a temperature of 90° C. for the wet etching. A depth of the via increases with time, until the dielectric layer 221 is penetrated. The mask layer 100 is removed. That is, the connection via 221a is formed. An inclination angle of the connection via 221a is in a range of about 0° to about 45°. For example, the inclination angle of the connection via 221a is 15°. When the mask layer 100 is made of the photoresist, the photoresist is cleaned with acetone by means of ultrasonic waves such that the photoresist is removed. When the mask layer 100 is made of the silicon dioxide film, the silicon dioxide film is etched away with diluted hydrofluoric acid. In addition, if the dielectric layer 221 is made of the glass, the wet etching process is at a temperature of 25° C., wherein a ratio of 40% NF4F solution to 49% HF solution is in a range of 4.8:1 to 5.2:1.
In another example, for a silicon substrate with a crystal orientation (100) as the dielectric layer 221, firstly, a mask layer 100 is formed on a first surface of the dielectric layer 221 through a photolithographic process. For example, the mask layer 100 is formed of a photoresist or a silicon dioxide film. The dielectric layer 221 is placed into a vacuum chamber of a reactive ion etching device or an inductively coupled plasma etching device for the dry etching, wherein a gas pressure is in a range of 40 Pa to 60 Pa and a ratio of Cl2 gas to He gas is in a range of 3:10 to 6:10, and the dielectric layer 221 is heated to 40° C. A depth of the via increases with time, until the dielectric layer 221 is penetrated. The mask layer 100 is removed. That is, the connection via 221a is formed. An inclination angle of the connection via 221a is in a range of about 0° to about 5°. For example, the inclination angle of the connection via 221a is 5°. When the mask layer 100 is made of the photoresist, the photoresist is cleaned with acetone by means of ultrasonic waves such that the photoresist is removed. When the mask layer 100 is made of the silicon dioxide film, the silicon dioxide film is etched away with diluted hydrofluoric acid. In addition, if the dielectric layer 221 is made of the glass, the dry etching process is at a temperature of 25° C. and at a gas pressure in a range of 250 Pa to 450 Pa, wherein a proportion of CF4 is in a range of 80 to 100, a proportion of CHF3 is in a range of 25 to 35 and a proportion of He is in a range of 110 to 130.
S222, cleaning the dielectric layer 221, after step S221, so that residues, debris (221b shown in
In some examples, step S222 may specifically include: the dielectric layer 221 is placed into a water tank, wherein the dielectric layer 221 is firstly subjected to ultrasonic cleaning to remove floating dust on a surface of the dielectric layer; the dielectric layer 221 is then immersed in a solution containing hydrofluoric acid for chemical corrosion, so that defects, such as microcrack areas Q1, stress concentration areas Q2 and the like, which are near the connection via 221a and in its inner wall on the dielectric layer 221 made of glass, Si or SOI, may be thoroughly removed through the chemical corrosion. A content of HF in the solution is approximately in a range of 1% to 20%, and NH4F may or may not be contained in the solution. When NH4F is contained, a content of NH4F is approximately in a range of 10 to 40%, a temperature of the solution is approximately in a range of 35° C. to 60° C., a duration for the chemical corrosion is approximately in a range of 30 seconds to 5 minutes. Then, the dielectric layer 221 is thoroughly washed by the pure deionized water, and finally, is dried by the air knife. The chemically corroded connection via 221a has smooth inner wall and surface and does not contain the defects, such as microcrack areas Q1, stress concentration areas Q2 and the like.
S223, after the step S222, applying a metal paste 2220 into the connection via 221a of the dielectric layer 221, and forming the metal paste 2220 on the first surface and the second surface of the dielectric layer 221; and then, curing the metal paste 2220 on the first surface and the second surface, respectively, to form a connection electrode 22203 filled in the connection via 221a, a first extraction electrode 22201 on the first surface and a second extraction electrode 22202 on the second surface.
In some examples, the metal paste 2220 may be a conductive paste. A material of the conductive paste includes, but is not limited to, a low-temperature curing type polymer conductive paste, and main components of the conductive paste include conductive particles, a resin, a curing agent, a dispersant, a diluent, an adhesion enhancer, and an anti-settling agent. The conductive particles may be selected from Cu, Ag and Au, and a size of each particle is approximately in a range of 1 nm to 100 um. The resin may be bisphenol epoxy resin. The curing agent may be acid anhydrides. The dispersant may be methylimidazole. The diluent may be butyl acetate. The adhesion enhancer may be tetraethyl titanate. The anti-settling agent may be polyamides.
Step S223 may specifically include: firstly, coating the conductive paste in the connection via 221a and around an edge of the connection via 221a on the second surface, and then, performing solvent drying and thermocuring processes on the second surface of the dielectric layer 221 to form the connection electrode 22203 filled in the connection via 221a and the second extraction electrode 22202 located on the second surface; then, coating the conductive paste around an edge of the connection via 221a on the first surface of the dielectric layer 221, and then, performing solvent drying and thermocuring processes on the first surface of the dielectric layer 221 to form the first extraction electrode 22201 located on the first surface. The preferred mode for coating the conductive paste includes, but is not limited to, screen printing, ink-jet printing, slit coating or the like. A vacuum adsorption machine is used in cooperation when the conductive paste is coated, so that the coating efficiency may be improved, and a distribution profile of the conductive paste on the wall and the edge of the connection via may be improved. The solvent drying process may be performed under an atmospheric pressure of air, an atmospheric pressure of N2 or the vacuum, at a temperature in a range of about 40° C. to about 95° C., for a duration in a range of about 1 min to about 30 min. The thermocuring process may be performed in an oven, under the atmosphere of N2, at a heating temperature in a range of about 140° C. to about 200° C. Alternatively, the curing process may be performed by means of illumination with laser beams, which have a wavelength in a range of about 500 nm to about 1510 nm, a laser power in a range of 50 mW to 50 W, and a beam diameter in a range of about 10 um to about 2000 um, and the laser beams may be a single beam or multiple beams.
S231, preparing a dielectric layer 231; and forming a connection via 231a extending through the dielectric layer 231 through a patterning process.
In some examples, step S231 may specifically include: forming the connection via 231a in the dielectric layer 231 through an etching process. The etching process includes two types of etching processes, that is, a wet etching process and a dry etching process. The connection via 231a may be formed in the dielectric layer 231 by reasonably selecting the type of the etching process, a formula of etching liquid or a proportion of etching gas, an etching duration, a temperature and the like. It will be described below that the connection via 231a extending through the dielectric layer 231 is formed through the wet etching process and the dry etching process, respectively.
In one example, for a silicon substrate with a crystal orientation (100) as the dielectric layer 231, firstly, a mask layer 100 is formed on a first surface of the dielectric layer 231 through a photolithographic process. For example, the mask layer 100 is formed of a photoresist or a silicon dioxide film. The dielectric layer 231 is placed into a tetramethyl ammonium hydroxide aqueous solution at a temperature of 90° C. for the wet etching. A depth of the via increases with time, until the dielectric layer 231 is penetrated. The mask layer 100 is removed. That is, the connection via 231a is formed. An inclination angle of the connection via 231a is in a range of about 0° to about 45°. For example, the inclination angle of the connection via 231a is 15°. When the mask layer 100 is made of the photoresist, the photoresist is cleaned with acetone by means of ultrasonic waves such that the photoresist is removed. When the mask layer 100 is made of the silicon dioxide film, the silicon dioxide film is etched away with diluted hydrofluoric acid. In addition, if the dielectric layer 231 is made of the glass, the wet etching process is at a temperature of 25° C., wherein a ratio of 40% NF4F solution to 49% HF solution is in a range of 4.8:1 to 5.2:1.
In another example, for a silicon substrate with a crystal orientation (100) as the dielectric layer 231, firstly, a mask layer 100 is formed on a first surface of the dielectric layer 231 through a photolithographic process. For example, the mask layer 100 is formed of a photoresist or a silicon dioxide film. The dielectric layer 231 is placed into a vacuum chamber of a reactive ion etching device or an inductively coupled plasma etching device for the dry etching, wherein a gas pressure is in a range of 40 Pa to 60 Pa and a ratio of Cl2 gas to He gas is in a range of 3:10 to 6:10, and the dielectric layer 231 is heated to 40° C. A depth of the via increases with time, until the dielectric layer 191 is penetrated. The mask layer 100 is removed. That is, the connection via 231a is formed. An inclination angle of the connection via 231a is in a range of about 0° to about 5°. For example, the inclination angle of the connection via 231a is 5°. When the mask layer 100 is made of the photoresist, the photoresist is cleaned with acetone by means of ultrasonic waves such that the photoresist is removed. When the mask layer 100 is made of the silicon dioxide film, the silicon dioxide film is etched away with diluted hydrofluoric acid. In addition, if the dielectric layer 231 is made of the glass, the dry etching process is at a temperature of 25° C. and at a gas pressure in a range of 250 Pa to 450 Pa, wherein a proportion of CF4 is in a range of 80 to 100, a proportion of CHF3 is in a range of 25 to 35 and a proportion of He is in a range of 110 to 130.
S232, cleaning the dielectric layer 231, after step S231, so that residues, debris (231b shown in
In some examples, step S232 may specifically include: placing the dielectric layer 231 into a water tank containing pure deionized water or a combination of the deionized water with a proper amount of cleaning agent (such as an oil-based cleaning agent or a water-based cleaning agent) at a temperature approximately in a range of 35° C. to 70° C., wherein the water is subjected to cavitation, acceleration and direct flow actions by means of ultrasonic waves (with a frequency approximately in a range of 10 kHz to 10 MHz), so that a pollutant layer is dispersed, emulsified and stripped to achieve the purpose of cleaning, wherein the cleaning time is approximately in a range of 2 to 20 minutes; and finally, washing the dielectric layer 231 by using the pure deionized water, and taking the dielectric layer 231 out of the water tank, and drying the dielectric layer 231 by using an air knife.
S233, forming a chemical plating medium 2320 on the first surface and the second surface of the dielectric layer 231 provided with the connection via 231a after the step S232.
In some examples, step S233 may specifically include: placing the dielectric layer 231, in a spraying mode or directly, into a water tank containing a solution of the chemical plating medium 2320, so that a layer of Sn2+ is adsorbed on surfaces of the dielectric layer 231. The solution of the chemical plating medium 2320 mainly contains SnCl2 of 10 g/L to 30 g/L, concentrated hydrochloric acid (having a concentration of 38%) of 20 ml/L to 60 ml/L and deionized water. A less number of Sn particles are added into the solution to prevent the Sn2+ from being oxidated. Then, the dielectric layer 231 is placed, in a spraying mode or directly, into a water tank containing an activation solution, so that surfaces of the dielectric layer 231 reacts with the activation solution (mainly containing SnCl2 of 80 g/L to 120 g/L, concentrated hydrochloric acid of 300 ml/L to 500 ml/L, Na2SnO3 of 10 g/L to 20 g/L, PdCl2 of 1 g/L to 4 g/L and deionized water), to generate metal palladium particles which are tightly attached to the surfaces of the dielectric layer 231. That is, the chemical plating medium 2320 is formed on the first surface and the second surface of the dielectric layer 231 provided with the connection via 231a.
S234, after the step S233, performing a chemical plating process on the dielectric layer 231 with the chemical plating medium 2320 to form metal films on the first surface and the second surface of the dielectric layer 231, and in the connection via 231a, and patterning the metal films formed on the first surface and the second surface of the dielectric layer 231, for forming a first extraction electrode 23201 and a second extraction electrode 23202, and a connection electrode 23203 in the connection via 231a.
In some examples, the chemically plated metal films may be a single-layer metal film or may be metal films stacked together. For example: only a Cu metal film is plated to form a single-layer metal film (having a thickness in a range of about 1 um to about 100 um). Alternatively, it is also possible to firstly plate a Ni metal film (having a thickness in a range of about 10 um to about 100 um), and then a Cu metal film (having a thickness in a range of about 1 um to about 100 um), wherein the Ni metal film is used to increase the adhesion of the Cu metal film. In the embodiment of the present disclosure, as an example, a material of the single-layer metal film is Cu, and a material of metal films stacked together is Ni/Cu, which does not limit the scope of the embodiment of the present disclosure. It will be described below by taking an example in which Ni/Cu metal films are chemically plated.
In some examples, step S234 may specifically include: placing the dielectric layer 231 into the chemical plating solution, and sequentially performing the chemical plating process with metal Ni and Cu. Then, the metal films formed on the first surface and the second surface of the dielectric layer 231 are patterned, for forming the first extraction electrode 23201 and the second extraction electrode 23202, and the connection electrode 23203 in the connection via 231a. The Ni solution for the chemical plating generally contains NiSO4·6H2O of 10 g/L to 30 g/L, NaH2PO4·2H2O 20 g/L to 40 g/L, Na-Citrate of 5 g/L to 15 g/L and NH4Cl of 20 g/L to 40 g/L, the solution is alkaline, has a PH in a range of 8.0 to 10.0 and a temperature in a range of 75° C. to 90° C. The Cu solution for the chemical plating generally contains KNaC4H406 of 30 g/L to 50 g/L, NaOH of 8 g/L to 10 g/L, Na2CO3 of 38 g/L to 40 g/L, CuSO4 of 10 g/L to 20 g/L, NiCl2 of 2 g/L to 6 g/L and formaldehyde of 40 ml/L to 60 ml/L with a concentration of 35%, the solution is alkaline, has a PH in a range of 11.0 to 14.0 and a temperature in a range of 55° C. to 65° C.
S241, preparing a dielectric layer 241; and forming a connection via 241a extending through the dielectric layer 241 through a patterning process.
In some examples, step S241 may specifically include: forming the connection via 241a in the dielectric layer 241 through an etching process. The etching process includes two types of etching processes, that is, a wet etching process and a dry etching process. The connection via 241a may be formed in the dielectric layer 241 by reasonably selecting the type of the etching process, a formula of etching liquid or a proportion of etching gas, an etching duration, a temperature and the like. It will be described below that the connection via 241a extending through the dielectric layer 241 is formed through the wet etching process and the dry etching process, respectively.
In one example, for a silicon substrate with a crystal orientation (100) as the dielectric layer 241, firstly, a mask layer 100 is formed on a first surface of the dielectric layer 241 through a photolithographic process. For example, the mask layer 100 is formed of a photoresist or a silicon dioxide film. The dielectric layer 241 is placed into a tetramethyl ammonium hydroxide aqueous solution at a temperature of 90° C. for the wet etching. A depth of the via increases with time, until the dielectric layer 241 is penetrated. The mask layer 100 is removed. That is, the connection via 241a is formed. An inclination angle of the connection via 241a is in a range of about 0° to about 45°. For example, the inclination angle of the connection via 241a is 15°. When the mask layer 100 is made of the photoresist, the photoresist is cleaned with acetone by means of ultrasonic waves such that the photoresist is removed. When the mask layer 100 is made of the silicon dioxide film, the silicon dioxide film is etched away with diluted hydrofluoric acid. In addition, if the dielectric layer 241 is made of the glass, the wet etching process is at a temperature of 25° C., wherein a ratio of 40% NF4F solution to 49% HF solution is in a range of 4.8:1 to 5.2:1.
In another example, for a silicon substrate with a crystal orientation (100) as the dielectric layer 241, firstly, a mask layer 100 is formed on a first surface of the dielectric layer 241 through a photolithographic process. For example, the mask layer 100 is formed of a photoresist or a silicon dioxide film. The dielectric layer 241 is placed into a vacuum chamber of a reactive ion etching device or an inductively coupled plasma etching device for the dry etching, wherein a gas pressure is in a range of 40 Pa to 60 Pa and a ratio of Cl2 gas to He gas is in a range of 3:10 to 6:10, and the dielectric layer 241 is heated to 40° C. A depth of the via increases with time, until the dielectric layer 241 is penetrated. The mask layer 100 is removed. That is, the connection via 241a is formed. An inclination angle of the connection via 241a is in a range of about 0° to about 5°. For example, the inclination angle of the connection via 241a is 5°. When the mask layer 100 is made of the photoresist, the photoresist is cleaned with acetone by means of ultrasonic waves such that the photoresist is removed. When the mask layer 100 is made of the silicon dioxide film, the silicon dioxide film is etched away with diluted hydrofluoric acid. In addition, if the dielectric layer 241 is made of the glass, the dry etching process is at a temperature of 25° C. and at a gas pressure in a range of 250 Pa to 450 Pa, wherein a proportion of CF4 is in a range of 80 to 100, a proportion of CHF3 is in a range of 25 to 35 and a proportion of He is in a range of 110 to 130.
S242, cleaning the dielectric layer 241, after step S241, so that residues, debris (241b shown in
In some examples, step S242 may specifically include: the dielectric layer 241 is placed into a water tank, wherein the dielectric layer 241 is firstly subjected to ultrasonic cleaning to remove floating dust on a surface of the dielectric layer, the dielectric layer 241 is then immersed in a solution containing hydrofluoric acid for chemical corrosion, so that defects, such as microcrack areas Q1, stress concentration areas Q2 and the like, which are near the connection via 241a and in its inner wall on the dielectric layer 241 made of glass, Si or SOI, may be thoroughly removed through the chemical corrosion. A content of HF in the solution is approximately in a range of 1% to 20%, and NH4F may or may not be contained in the solution. When NH4F is contained, a content of NH4F is approximately in a range of 10 to 40%, a temperature of the solution is approximately in a range of 35° C. to 60° C., a duration for the chemical corrosion is approximately in a range of 30 seconds to 5 minutes. Then, the dielectric layer 241 is thoroughly washed by the pure deionized water, and finally, is dried by the air knife. The chemically corroded connection via 241a has smooth inner wall and surface and does not contain the defects, such as microcrack areas Q1, stress concentration areas Q2 and the like.
S243, forming a chemical plating medium 2420 on the first surface and the second surface of the dielectric layer 241 provided with the connection via 241a after the step S242.
In some examples, step S243 may specifically include: placing the dielectric layer 241, in a spraying mode or directly, into a water tank containing a solution of the chemical plating medium 2420, so that a layer of Sn2+ is adsorbed on surfaces of the dielectric layer 241. The solution of the chemical plating medium 2420 mainly contains SnCl2 of 10 g/L to 30 g/L, concentrated hydrochloric acid (having a concentration of 38%) of 20 ml/L to 60 ml/L and deionized water. A less number of Sn particles are added into the solution to prevent the Sn2+ from being oxidated. Then, the dielectric layer 241 is placed, in a spraying mode or directly, into a water tank containing an activation solution, so that surfaces of the dielectric layer 241 reacts with the activation solution (mainly containing SnCl2 of 80 g/L to 120 g/L, concentrated hydrochloric acid of 300 ml/L to 500 ml/L, Na2SnO3 of 10 g/L to 20 g/L, PdCl2 of 1 g/L to 4 g/L and deionized water), to generate metal palladium particles which are tightly attached to the surfaces of the dielectric layer 241. That is, the chemical plating medium 2420 is formed on the first surface and the second surface of the dielectric layer 241 provided with the connection via 241a.
S244, after the step S243, performing a chemical plating process on the dielectric layer 241 with the chemical plating medium 2420 to form metal films on the first surface and the second surface of the dielectric layer 121, and in the connection via 241a, and patterning the metal films formed on the first surface and the second surface of the dielectric layer 241, for forming a first extraction electrode 24201 and a second extraction electrode 24202, and a connection electrode 24203 in the connection via 241a.
In some examples, the chemically plated metal films may be a single-layer metal film or may be metal films stacked together. For example: only a Cu metal film is plated to form a single-layer metal film (having a thickness in a range of about 1 um to about 100 um). Alternatively, it is also possible to firstly plate a Ni metal film (having a thickness in a range of about 10 um to about 100 um), and then a Cu metal film (having a thickness in a range of about 1 um to about 100 um), wherein the Ni metal film is used to increase the adhesion of the Cu metal film. In the embodiment of the present disclosure, as an example, a material of the single-layer metal film is Cu, and a material of metal films stacked together is Ni/Cu, which does not limit the scope of the embodiment of the present disclosure. It will be described below by taking an example in which Ni/Cu metal films are chemically plated.
In some examples, step S244 may specifically include: placing the dielectric layer 241 into the chemical plating solution, and sequentially performing the chemical plating process with metal Ni and Cu. Then, the metal films formed on the first surface and the second surface of the dielectric layer 241 are patterned, for forming the first extraction electrode 24201 and the second extraction electrode 24202, and the connection electrode 24203 in the connection via 241a. The Ni solution for the chemical plating generally contains NiSO4·6H2O of 10 g/L to 30 g/L, NaH2PO4·2H2O 20 g/L to 40 g/L, Na-Citrate of 5 g/L to 15 g/L and NH4Cl of 20 g/L to 40 g/L, the solution is 15 alkaline, has a PH in a range of 8.0 to 10.0 and a temperature in a range of 75° C. to 90° C. The Cu solution for the chemical plating generally contains KNaC4H406 of 30 g/L to 50 g/L, NaOH of 8 g/L to 10 g/L, Na2CO3 of 38 g/L to 40 g/L, CuSO4 of 10 g/L to 20 g/L, NiCl2 of 2 g/L to 6 g/L and formaldehyde of 40 ml/L to 60 ml/L with a concentration of 35%, the solution is alkaline, has a PH in a range of 11.0 to 14.0 and a temperature in a range of 55° C. to 65° C.
Twenty-four examples of a method for forming a conductive via are listed above, but it should be understood that the above description is only illustrative and should not be construed as limiting the scope of the embodiments of the present disclosure.
It should be noted that the method for forming a conductive via in a dielectric layer is provided as above, and accordingly, the method may be similarly used to form a blind via 251a in the dielectric layer, as shown in
In a second aspect,
In the embodiment of the present disclosure, materials of the dielectric layer 11, the connection electrode 2203, the first extraction electrode 2201 and the second extraction electrode 2202 may be the same as those in the above embodiment, and thus are not described herein again. In the embodiment of the present disclosure, a structure provided with such a conductive via may be applied to memory chips, high-brightness LEDs, high-quality-factor (Q-factor) inductor devices in radio frequency circuits and integrated passive devices, etc., thereby improving the integration level, and reducing a resistance.
It should be noted that the conductive via in the embodiment of the present disclosure may be formed by any of the methods as described above, so that the materials and the sizes of the dielectric layer 11, the connection electrode 2203, the first extraction electrode 2201, and the second extraction electrode 2202 of the conductive via may all be the same as those described above. In addition, the shape and the size of the connection via may also be the same as those of the above structure, which is not described herein again.
In a third aspect, an embodiment of the present disclosure provides a passive device including the above conductive via. In some examples, the passive device includes at least an inductor, but may also include a capacitor and a resistor. In the following description, the passive device includes an inductor, a capacitor and a resistor, as an example.
A first interlayer dielectric layer 30 is arranged on a side of the plurality of second sub-structures 2202a of the inductor 200 away from the dielectric layer 11, and a first pad 501 and a second pad are arranged on a side of the first interlayer dielectric layer 30 away from the dielectric layer 11. A second connection via and a third connection via are provided in the first interlayer dielectric layer 30, the first pad 501 is electrically connected to a first signal terminal of the inductance coil 201 through the second connection via, and the second pad is electrically connected to a second signal terminal 202 of the inductance coil 201 through the third connection via. The first pad 501 and the second pad are configured such that the inductor 200 is electrically connected to a radio frequency circuit. For example: the inductor 200 is bonded to a PCB (printed circuit board) through the first pad 501 and the second pad, or the inductor 200 is electrically connected to the PCB by soldering. A resistor 60 may be disposed on the second surface of the dielectric layer 11, and may be made of a high-resistance material, such as tin oxide (ITO) or nickel-chromium (NiCr) alloy. In some examples, a first plate 701 of a capacitor 700 may be disposed on a same layer as the plurality of second sub-structures 2202a of the inductor 20, and a second plate 702 of the capacitor 700 may be disposed on a same layer as the first pad 501 and a third pad 503. In this way, the passive device is easily manufactured without increasing the number of process steps.
In addition, in the embodiment of the present disclosure, the third pad 503, a fourth pad 504, a fifth pad 505, and a sixth pad may be further disposed on a same layer as the first pad 501 and the second pad. The third pad is connected to a first terminal of the resistor 60 through a fourth connection via extending through the first interlayer dielectric layer 30, the fourth pad 54 is connected to a second terminal of the resistor 60 through a fifth connection via extending through the first interlayer dielectric layer 30, the fifth pad 505 is connected to the first plate 701 of the capacitor 700 through a sixth connection via extending through the first interlayer dielectric layer 30, and the sixth pad and the second plate 702 of the capacitor 70 may have a one-piece structure. The third pad and the fourth pad 504 are configured to connect the resistor 60 to the radio frequency circuit, and the fifth pad 505 and the sixth pad 506 are configured to connect the capacitor 700 to the radio frequency circuit. It should be understood that the capacitor 700 and the resistor 60 are electrically connected to devices on the substrate, which is not necessarily realized by the pads.
In some examples, the dielectric layer includes, but is not limited to, at least one of glass, polyimide, polyethylene terephthalate, cyclic olefin polymer.
In some examples, a first protective layer 40 is disposed on a side of the plurality of first sub-structures 2201a of the inductor 200 away from the dielectric layer 11 to prevent the plurality of first sub-structures 2201a from being oxidized due to exposure. The first protective layer 40 is made of an inorganic insulating material. For example: the first protective layer 40 is an inorganic insulating layer formed of silicon nitride (SiNx), or silicon oxide (SiO2), or a composite layer formed by the inorganic insulating layers of SiNx and SiO2 stacked together.
In the embodiment of the present disclosure, the passive device includes the above structure provided with the conductive via, which may be applied to memory chips, high-brightness LEDs, high-quality-factor (Q-factor) inductor devices in radio frequency circuits and integrated passive devices, etc., thereby improving the integration level, and reducing a resistance.
It should be understood that the above embodiments are merely exemplary embodiments adopted to explain the principles of the present disclosure, and the present disclosure is not limited thereto. It will be apparent to one of ordinary skill in the art that various changes and modifications may be made therein without departing from the spirit and scope of the present disclosure, and such changes and modifications also fall within the scope of the present disclosure.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2021/102525 | 6/25/2021 | WO |
