1. Field of the Invention
The present invention relates to a semiconductor device having a built-in semiconductor chip and a manufacturing method of such a semiconductor device.
2. Description of Related Art
In prior art, an electrical connection between a semiconductor chip and an external electrode has been effected by means of wire-bonding, as described in Japanese Patent Publication Laid-open No. 2006-278520. Referring to
Another exemplary connecting form for the semiconductor device is shown in
However, it should be noted that the former semiconductor device adopting the bonding wire raises a problem to be solved, as follows
With the progress of electronic equipments, such as mobile telephones, there is a requirement of improving the electrical characteristics of electronic components. In the above semiconductor device using the bonding wire, nevertheless, it is difficult to improve the electrical characteristics of the device since its electrical resistance value is increased at the bonding wire. Additionally, as the front pole 1001a of the semiconductor chip 1001 is connected to the external electrode 1003 one on one shown in
Although the latter semiconductor device 1010 of
Further, an exfoliation may arise between the semiconductor chip and members interposing the chip by a reliability test or an impact of drop. This would be also at the root of deteriorating the process yield.
In common with the semiconductor devices of
In the above-mentioned situation, it is an object of the present invention to provide a semiconductor device and its manufacturing method both capable of ensuring high reliability while improving its electrical characteristics with the structure requiring no bonding wires and also improving the productivity with raised process yield.
In order to attain the above object, according to a first aspect of the present invention, there is provided a semiconductor device comprising: a semiconductor chip having a first surface on which a first pole of a semiconductor element is arranged and a second surface on which a second pole of the semiconductor element is arranged, the first surface opposing the second surface; a first conductive member connected to the first surface of the semiconductor chip; a second conductive member connected to the second surface of the semiconductor chip; a first external electrode connected to the first conductive member, the first external electrode having a contact area larger than that of the first conductive member; a second external electrode connected to the second conductive member, the second external electrode having a contact area larger than that of the second conductive member; and a sealing member arranged between the first external electrode and the second external electrode to seal up the semiconductor chip, the first conductive member and the second conductive member, wherein the sealing member is made of a material that can be molten and subsequently hardened by heating.
According to a second aspect of the present invention, there is also provided a manufacturing method of a semiconductor device, comprising the steps of: forming a plurality of through-holes in a first sheet-shaped sealing material and a second sheet-shaped sealing material respectively; adhering the first and the second sheet-shaped members having the through-holes to a first external electrode and a second external electrode respectively; filling a conductive material in each of the through-holes formed in the first and the second sheet-shaped sealing materials to thereby form a first conductive member and a second conductive member; preparing a semiconductor chip having a first surface on which a first pole of a semiconductor element is arranged and a second surface on which a second pole of the semiconductor element is arranged, the first surface opposing the second surface; connecting the first conductive member and the second conductive member to the first pole of the semiconductor chip and the second pole of the semiconductor chip, respectively; applying pressure and heat on the first external electrode and the second external electrode toward the semiconductor chip interposed between the first conductive member and the second conductive member to melt the first sheet-shaped sealing material and the second sheet-shaped sealing material thereby sealing up the semiconductor chip, the first conductive member and the second conductive member; and further heating the first sheet-shaped sealing material and the second sheet-shaped sealing material to harden them.
Embodiments of the present invention will be described with reference to attached drawings.
According to the first embodiment, a semiconductor device 1 as a whole is provided in the form of a substantially-rectangular parallelepiped shown in
A first conductive member 6a is connected to the first surface 5a of the semiconductor chip 5, while a second conductive member 6b is connected to the second surface 5b. Outside the first conductive member 6a in the longitudinal direction of the device 1, a first external electrode 2a is connected to the other surface of the member 6a. Similarly, a second external electrode 3b is connected to the other surface of the second conductive member 6b.
With the above-mentioned arrangement of the semiconductor chip 5 inside the semiconductor device 1, as chip's opposing surfaces each having a maximum area in the semiconductor chip 5 can be allocated to its conductive surfaces for electrical contact with the external electrodes 2a, 2b (i.e. the conductive members 6a, 6b), it is possible to improve the electrical characteristics of the semiconductor device 1. In operation, current flows through the external electrode 2b, the second conductive member 6b, the second surface 5b (the second pole 5b1, the first surface 5a (the first pole 5a1), the first conductive member 6a and finally, through the external electrode 2a, in this order or flows though these elements in the opposite direction.
Each area of the first and the second surfaces 5a, 5b (or each sectional area of the first and the second conductive members 6a, 6b) is larger than each sectional area of the first and the second external electrodes 2a, 2b. With such dimensions of the semiconductor chip 5 and the conductive members 6a, 6b, it is possible to arrange these components at a substantially intermediate part of the semiconductor device 1, allowing the circumferences of the semiconductor chip 5 and the conductive members 6a, 6b to be covered with the sealing member 3 throughout.
Referring to
First, a sealing material 3′ in the form of a sheet is prepared. This sheet-shaped sealing material 3′ has features of being molten by heating it up to a predetermined temperature (e.g. 130 degrees centigrade) for fluidization and nevertheless hardened since a further heating-up reaches e.g. 175 degrees centigrade. Thus, the sheet-shaped sealing material 3′ can be formed to have an optional profile by pressurizing it during the fluidization, which is superior to its machinability. Additionally, it is also possible to modify only the color of the sheet-shaped sealing material 3 without altering its material properties.
A thickness T (see
Next, by an operation using laser or drill (both not shown), a plurality of through-holes 3a are formed in the sheet-shaped sealing material 3′ to receive the conductive members 6 (see
Using a not-shown laminating machine (called “laminator” generally), for example, the sheet-shaped sealing material 3′ having the through-holes 3a formed therein is press-fitted to the external electrode 2 temporarily. As the semiconductor device 1 requires a pair of external electrodes 2 having the press-fitted sheet-shaped sealing materials 3′, 3′, it is necessary to prepare two or more “in-process” products each having the sheet-shaped sealing material 3′ fitted to the external electrode 2.
Next, the through-holes 3a of the sheet-shaped sealing material 3′ temporarily press-fitted to the external electrode 2 are filled up with conductive members (conductive material) 6, as shown in
Next, the semiconductor chips 5 are mounted on the second external electrode 2b so that the second surface 5b of each chip 5 abuts on the second conductive member 6b on the electrode 2b. On the other hand, the first electrode 2a having the sheet-shaped sealing material 3′ press-fitted thereto is mounted on the semiconductor chips 5 so that the first conductive member 6a abuts on the first surface 5a of each chip 5. In this way, the semiconductor chips 5 are sandwiched between the first external electrode 2a and the second electrode 2b, as shown in
Then, as shown with arrows of
After the sheet-shaped sealing materials 3′ and the conductive members 6 (6a, 6b) are together hardened, the resultant integrated body (in-process product) is diced, between the adjoining semiconductor chips 5, by a dicing cutter thinner than an interval of the adjoining semiconductor chips 5, as shown with broken lines of
Thus, Owing to the provision of the semiconductor device 1 where the semiconductor chip 5 is sealed up with the sealing member 3 and additionally, the chip's polar surfaces are electrically connected to the external electrodes 2 through the conductive members 6, it becomes possible to provide a semiconductor device and its manufacturing method both capable of ensuring high reliability while improving its electrical characteristics with the structure requiring no bonding wires and also improving the productivity with raised process yield.
Thus, by using the sheet-shaped sealing material 3′ fusible at a predetermined temperature, due to its flexibility, it is possible to prevent the semiconductor chip 5 from being damaged in manufacturing the semiconductor device 1. Additionally, as the conductive members 6 are disposed in the through-holes 3a of the sealing material 3′ in process of manufacturing the semiconductor device 1, the adjustment in size of the through-holes 3a allows the character of the device 1 to be controlled in terms of its conductive path for current and the wiring length to thereby improve the electrical characteristics. According to the above-mentioned manufacturing method, since the conductive members and the external electrodes can be together connected to a large number of semiconductor tips at a time, it is possible to improve the productivity for semiconductor devices with a shortened manufacturing time.
Besides the above-mentioned effects, the welding state of solder in mounting the semiconductor device 1 on a substrate is visible since the semiconductor device 1 of the first embodiment has a pair of electrodes each consisting of five surfaces. Thus, as the structure of the semiconductor device 1 allows solder to constitute a sufficient fillet between the external electrode and the substrate, it is possible to prevent the semiconductor device 1 from being damaged due to an external force such as impact.
The second embodiment of the present invention will be described below. In the second embodiment, elements identical to those of the first embodiment are indicated with the same reference numerals and their overlapping descriptions are eliminated.
The second embodiment is directed to prevention of a breakage of the semiconductor device originating in one boundary between the semiconductor chip and the conductive member and another boundary between the conductive member and the external electrode at the package reliability evaluation test (e.g. share test) or at a substrate's bending due to heat of use.
In the semiconductor chip 5, the first pole 5a1 is arranged on the first surface 5a. The first surface 5a is connected to the external electrode 2 through the conductive member 6. The external electrode 2 is partially coated with the plating film 4. The semiconductor chip 5 and the conductive member 6 are sealed up with the sealing member 3. In order to accomplish total contact of the conductive member 6 with the whole first surface 5a of the semiconductor chip 5, the contact surface of the member 6 for connection with the first surface 5a has an area equal to the area of the first surface 5a of the chip 5.
On the other hand, the semiconductor chip 5 has the second pole 5b1 arranged on the second surface 5b so as to oppose the first pole 5a1. The second pole 5b1 is not connected to the conductive member 6 and the external electrode 2. Instead, plating is directly applied on the second pole 5b1 and the sealing member 3 enclosing the semiconductor chip 5.
Consequently, as shown in
In the semiconductor device 11a, a plating film 4x for the external electrode 2x is formed so as to cover the boundary between the conductive member 6x and the external electrode 2x, while another plating film 14x for the second surface 5b of the semiconductor chip 5 is formed so as to cover the boundary between the semiconductor chip 5 and the conductive member 6x.
The manufacturing method of the semiconductor device 11 of the second embodiment will be described with reference to
First of all, a plate-shaped stage 17 is prepared and successively, a plurality of semiconductor chips 5 are mounted on the stage 17 so that the second pole 5b of each second surface 5b abuts on a surface of the stage 17, as shown in
Next, reversing the assembly of
After the sealing materials 3′ are hardened, the stage 17 is removed from the second surfaces 5b of the semiconductor chips 5. Successively, the resultant integrated body (assembly) is diced, between the adjoining semiconductor chips 5, by a dicing cutter thinner than an interval of the adjoining semiconductor chips 5, as shown with broken lines of
Therefore, also in the second embodiment, it is possible to provide a semiconductor device and its manufacturing method both capable of ensuring high reliability while improving its electrical characteristics with the structure requiring no bonding wires and also improving the productivity with raised process yield.
In addition to all effects by the first embodiment, as the semiconductor device 11 (11a) of the second embodiment has the semiconductor chip 5 shifted on one side of the device in the longitudinal direction, it is possible to prevent the semiconductor chip 5 from being broken, for example, its breakage originating in one boundary between the semiconductor chip and the conductive member and another boundary between the conductive member and the external electrode at the package reliability evaluation test (e.g. share test) or at a substrate's bending due to heat of use. Additionally, the deposition of the plating films 4, 14 (4x, 14x) covering these boundaries can reinforce the prevention of a breakage of the semiconductor chip 5.
The third embodiment of the present invention will be described below. In the third embodiment, elements identical to those of the first and the second embodiments are indicated with the same reference numerals and their overlapping descriptions are eliminated.
According to the third embodiment, a semiconductor device 21 is provided in the form of a substantially-rectangular parallelepiped, as shown in
Each conductive member 26 has one end in contact with the first pole 5a1 or the second pole 5b1, whose area is smaller than the area of the first surface 5a of the chip 5 or the second surface 5b, and the other end whose area is larger than the area of the first surface 5a of the chip 5 or the second surface 5b. That is, as shown in
As shown in
The method of the semiconductor device 21 of the third embodiment will be described with reference to
First, as shown in
Next, using drill or laser, a plurality of through-holes 23b are formed in the sealing material 23′ so as to center on respective midpoints between the adjoining grooves 23a, 23a (see
Then, as shown in
Successively, the component after the removal of the dicing sheet 27 is further reversed so that the sealing material's surface (in previous contact with the sheet 27) directs upwards. Note, the so-reversed component will be referred to as “second component 28b” after. The semiconductor tips 5 are mounted on the second component 28, at respective positions of the through-holes 23b. It is noted that the above vertical shaft 26a of the conductive member 26 is formed in each through-hole 23b. In arrangement, each of the semiconductor tips 5 is positioned so that the second surface 5b abuts on the leading end of the vertical shaft 26a.
Next, another component (referred to as “first component 28a” after) is prepared and further laid on the semiconductor tips 5 mounted on the second component 28b. In other words, the first component 28 is mounted on the semiconductor tips 5 in a manner that each vertical shaft 26b of the conductive member 26 abuts on each first surface 5a of the semiconductor tips 5. Consequently, the semiconductor tips 5 are sandwiched between the first component 28a and the second component 28b.
Finally, pressure with heat is applied on the first component 28a and the second component 28b interposing the semiconductor tips 5 therebetween to melt the sealing material 23′.
Therefore, also in the third embodiment, it is possible to provide a semiconductor device and its manufacturing method both capable of ensuring high reliability while improving its electrical characteristics with the structure requiring no bonding wires and also improving the productivity with raised process yield.
Additionally, since the conductive members 26 in the semiconductor device 21 serve as the previously-mentioned external electrodes, it is possible to avoid an omnibus dicing of different materials of metal (i.e. external electrodes) and resin (sealing material), which is generally regarded as a difficult machining, allowing the productivity to be improved due to the easiness in the manufacturing process of semiconductor devices.
The fourth embodiment of the present invention will be described below. Also in the fourth embodiment, elements identical to those of the first to the third embodiments are indicated with the same reference numerals and their overlapping descriptions are eliminated.
According to the fourth embodiment, a semiconductor device 31 is provided in the form of a substantially-rectangular parallelepiped, as shown in
In the semiconductor tip 5, the first pole 5a1 is arranged on the first surface 5a, while the second pole 5b1 is arranged on the second surface 5b. All surfaces of the chip 5 but the surfaces 5a, 5b are sealed up with a sealing material 38. The sealing material 38 is formed with a length equal to an interval between the first surface 5a and the second surface 5b. As shown in
Conductive members 36 (36a, 36b) are connected to the first surface 5a and the second surface 5b of the chip 5. In the conductive members 36, a first conductive member 36a is connected to the overall first surface 5a. In detail, as shown in
On the other hand, a second conductive member 36b is connected to the overall second surface 5b so as to align its one end 36ba (of the member 36b) with an end 5ba of the second surface 5b. That is, as shown in
A surface of the first conductive member 36a and a surface of the sealing material 38b, both surfaces of which constitute an identical plane with the first surface 5a of the chip 5, are together sealed up with a first sealing member 33a. Similarly, a surface of the second conductive member 36b and a surface of the sealing material 38a, both surfaces of which constitute an identical plane with the second surface 5b of the chip 5, are together sealed up with a second sealing member 33b.
In the later-mentioned manufacturing method, by a dicing process, the semiconductor devices are individualized in a manner that all of the first sealing member 33a, the other end 36ab of the first conductive member 36a, the sealing material 38a and the second sealing member 33b constitute an identical plane. The first plating film 34a is formed on such an identical plane.
By the dicing process, similarly, the semiconductor devices are also individualized in a manner that all of the second sealing member 33b, the other end 36bb of the second conductive member 36b, the sealing member 38b and the first sheet-shaped seaming material 33a constitute another identical plane. The second plating film 34b is formed on the identical plane. Thus, the semiconductor device 31 of the embodiment is formed, on both sides in the longitudinal direction, with the first plating film 34a and the second plating film 34b. When these plating films 34a, 35b are connected to a substrate through solders, the packaging of the semiconductor device 31 onto the substrate is accomplished. In the so-assembled semiconductor device 31, foe example, there is a current flow from the first plating film 34a to the second plating film 34b through the intermediary of the other end 36ab of the first conductive member 36a, the first conductive member 36a, the semiconductor tip 5, the second conductive member 36b and the other end 36bb of the second conductive member 36b, in this order.
The manufacturing method of the semiconductor device 32 of the fourth embodiment will be described with reference to
As shown in
While, in another process, the conductive members 36 are formed, at regular intervals, on a sheet-shaped sealing material 33′ by the printing method etc. Next, a sheet of
In mounting the semiconductor tip 5 on the second conductive member 36b, the positioning of both elements is carried out so as to connect the second conductive member 36b to the whole second surface 5b of the chip 5 and further align a chip's end abutting on the sealing material 38 with an end 36ba of the second conductive member 36b. With this positioning, not only the semiconductor tip 5 but a part of the sealing material 38 abutting on the other end of the chip 5 is connected onto the second conductive member 36b. Note, a sealing material's area in non-contact with the second conductive member 36b might produce a space against a second sheet-shaped sealing material 33b′. Nevertheless, this space would be sealed up with the second sheet-shaped sealing material 33b′ that has been molten and subsequently hardened.
Next, the first conductive member 36a is mounted on each first surface 5a of the semiconductor tips 5 for electrical connection, as shown in
Then, as shown with arrows of
The dicing is carried out so as to expose the end 36ab of the first conductive member 36a and the end 36bb of the second conductive member 36b for the purpose of accomplishing the subsequent electrical connection between the ends of the conductive members 36 and the subsequent plating films 34. On completion of the dicing process, the so-individualized semiconductor device 31 is transferred to a plating process where the plating films 34 are formed so as to cover the sealing members 33a, 33b, the conductive members 36 and the sealing materials 38. In this way, the semiconductor device 31 of
Therefore, also in the third embodiment, it is possible to provide a semiconductor device and its manufacturing method both capable of ensuring high reliability while improving its electrical characteristics with the structure requiring no bonding wires and also improving the productivity with raised process yield.
In addition, as the semiconductor device 31 of the fourth embodiment encloses the semiconductor chip 5 orientated so that its longitudinal direction is parallel with the longitudinal direction of the device 31, it is possible to prevent the semiconductor chip 5 from being broken, for example, its breakage originating in one boundary between the semiconductor chip and the conductive member and another boundary between the conductive member and the external electrode at the package reliability evaluation test (e.g. share test) or at a substrate's bending due to heat of use.
The fifth embodiment of the present invention will be described below. Also in the fifth embodiment, elements identical to those of the first to the fourth embodiments are indicated with the same reference numerals and their overlapping descriptions are eliminated.
According to the fifth embodiment, a semiconductor device 41 is provided in the form of a substantially-rectangular parallelepiped, as shown in
The difference between the fifth embodiment and the fourth embodiment resides in that the conductive members are formed by metal foils. The fifth embodiment is directed to a prevention of the conductive member from protruding into a space to be filled up with the sealing material 33 in the heating process under pressure. In order to ensure a conductive path, the fifth embodiment adopts the metal foils in place of the conductive members 36 of the fourth embodiment.
The manufacturing method of the semiconductor device 41 of the fourth embodiment will be described with reference to
First of all, metal foils are formed at regular intervals on a third sheet-shaped sealing material although they are not shown in the figures. The formation of the metal foils may be accomplished by first evaporating a metal film on the sealing material and successively etching the metal film to the metal foils.
In another process, as shown in
Next, preparing the former sheet-shaped sealing material having the metal foils etched, conductive adhesives 49 are arranged on the respective metal foils 46b on a sheet-shaped sealing material 43b′, at respective positions for mounting the semiconductor chips 5.
Removing the sealing material 43b from the dicing sheet 47, the resultant sealing material 43b′ (without the dicing sheet 47) is mounted on the metal foils 46b on the above the sheet-shaped sealing material 43b′, as shown in
Next, as shown in
Furthermore, another sheet-shaped sealing material 43a′ having the conductive adhesives 49 mounted on the metal foils 46a is prepared and mounted on the assembly of
Then, as shown with arrows of
The dicing is carried out so as to expose the end 46ab of the metal foil 46a and the end 46bb of the metal foil 46b for the purpose of accomplishing the subsequent electrical connection between the ends of these metal foils 46a, 46b and the subsequent plating films 44. On completion of the dicing process, the so-individualized semiconductor device 41 is transferred to a plating process where the plating films 44 are formed so as to cover the sealing member 43a, 43b, the metal foils 46a, 46b and the sealing members 48. In this way, the semiconductor device 41 of
Therefore, also in the third embodiment, it is possible to provide a semiconductor device and its manufacturing method both capable of ensuring high reliability while improving its electrical characteristics with the structure requiring no bonding wires and also improving the productivity with raised process yield.
In addition, as the semiconductor device 41 of the fifth embodiment encloses the semiconductor chip 5 orientated so that its longitudinal direction is parallel with the longitudinal direction of the device 41, it is possible to prevent the semiconductor chip 5 from being broken, for example, its breakage originating in one boundary between the semiconductor chip and the conductive member and another boundary between the conductive member and the external electrode at the package reliability evaluation test (e.g. share test) or at a substrate's bending due to heat of use. Additionally, owing to the provision of the above-mentioned manufacturing method, it is possible to eliminate the process of temporarily hardening the sheet-shaped sealing material enclosing the circumference of the semiconductor device, allowing the productivity of the semiconductor devices to be improved.
The sixth embodiment of the present invention will be described below. Also in the sixth embodiment, elements identical to those of the first to the fifth embodiments are indicated with the same reference numerals and their overlapping descriptions are eliminated.
The difference between the sixth embodiment and the first embodiment resides in that no conductive member is used to connect the semiconductor chip 5 to one external electrode 2.
For example, in the semiconductor device 1 of the first embodiment, the conductive member 6 such as silver (Ag) or copper (Cu) paste (subsequently hardened) is used to connect the semiconductor chip 5 to the external electrode 2.
Generally, the conductive member 6 contains binder resin for enhancing adhesion between the pole of the semiconductor chip 5 and the external electrode 2.
On the contrary, the sixth embodiment of the present invention is directed to a metal-to-metal joint between the first pole 5a1 of the semiconductor chip 5 and the external electrode 52a without using the above conductive member 6, for the purpose of preventing an exfoliation of adhesive boundary faces by the conductive member 6.
According to the sixth embodiment, a semiconductor device 51 is provided in the form of a substantially-rectangular parallelepiped, as shown in
In the semiconductor chip 5, the first pole 5a1 is connected to an end of the first external electrode 52a electrically. The first external electrode 52a is provided by applying plating on a through-hole 56aa formed in the first resin substrate 55a. The above-mentioned metal-to-metal joint is realized between the first external electrode 52a and the first pole 5a1 through this plating. The plating may be provided by means of either electrolytic plating or electroless plating. In the sixth embodiment, copper (Cu) is employed as the external electrode. However, the plating material is not limited to copper (Cu) only and it may be replaced by other metals, for example, gold (Au), nickel (Ni), tin (Sn) or the like.
When the though-hole 56aa is filled up with the plating metal, the first external electrode 52a has one end (or leading end) connected to the first pole 5a1. On the other hand, the other end of the electrode 52a is formed since the plating filling the through-hole 56aa is further deposited on an upper face of the first resin substrate 56a (i.e. one substrate's surface opposed to the other surface abutting on the surface 5a of the semiconductor chip 5 and the sealing member 53). Therefore, the other end of the electrode 52 has an area larger than that of the leading end of the electrode 52 or an area of the first surface 5a, so that the first external electrode 52a is formed to have a substantial T-shaped section.
As understood from
The manufacturing method of the semiconductor device 51 of the fifth embodiment will be described with reference to
First, a plurality of resin substrates 56 (56a, 56b) are prepared. Preferably, FR-4 or BT resin is available for the material forming the resin substrates 56.
For instance, by means of laser, drill or the like, a plurality of through-holes 56ba, 56aa are formed in the substrates 56b, 56a respectively, at regular intervals. The intervals between the adjoining through-holes 56ba, 56aa are optionally determined in light of the width of a dicing blade used in the later-mentioned dicing process, the position of the semiconductor chip 5 and so on. Also, the diameters of the through-holes 56ba, 56aa are determined corresponding to the required performance of the semiconductor device 51 on the assumption of certain connection with the poles 5b1, 5a1 on the surfaces 5b, 5a of the semiconductor chip 5.
Next, a plurality of through-holes 53a are formed in a sheet-shaped sealing material 53′ at the same pitch as the interval of the through-holes 56ba of the second resin substrate 56b by means of laser, drill or the like. Each of the through-holes 53a is provided for accommodating the semiconductor chip 5 while making its surfaces except for the first and the second surfaces 5a, 5b contact with respective surfaces defining the through-hole 53a. Next, using a laminator device, the so-formed sealing material 53′ is temporarily fixed on the second resin substrate 56b under slight pressure with heat. In fixing, the positioning of the second resin substrate 56b with respect to the sealing material 53′ is accomplished by according a diametral center of each through-hole 56b with a diametral center of the through-hole 53a.
Thereupon, the semiconductor chips 5 are fitted in the through-holes 53a in the sealing material 53′ and successively, the first resin substrate 56a is mounted on the semiconductor chips 5 and the sealing material 53′. In mounting, the first resin substrate 56a is positioned so that the through-holes 56a oppose the through-holes 56ba in the second resin substrate 56b through the semiconductor chips 5, respectively.
At this moment, the first and the second poles 5a1, 5b1 on the first and the second surface 5a, 5b of each semiconductor chip 5 are not obstructed by the first and the second resin substrates 56a, 56b due to the through-holes 56aa, 56ba, respectively.
Next, the plating process is carried out. The plating is applied on all of the through-holes 56aa, 56ba, one surface of the first resin substrate 56a opposed to the other surface in contact with the semiconductor chips 5 and the sealing material 53′ and one surface of the second resin substrate 56b opposed to the other surface in contact with the semiconductor chips 5 and the sealing material 53′, forming the external electrodes 52. Depending on the plating process, the electrodes 52 are made of copper (Cu), nickel (Ni), tin (Sn) or the like. Alternatively, the electrodes 52 may be formed by use of solder paste.
After completing the plating process, the resultant integrated body (assembly) is diced along broken lines of
Therefore, also in the sixth embodiment, it is possible to provide a semiconductor device and its manufacturing method both capable of ensuring high reliability while improving its electrical characteristics with the structure requiring no bonding wires and also improving the productivity with raised process yield.
Particularly, by plating the external electrodes, it is possible to produce the metal-to-metal joint in the connection between the poles of the semiconductor chip and the external electrodes. Thus, it is possible to prevent the semiconductor chip from being broken, for example, its breakage originating in one boundary between the semiconductor chip and the conductive member and another boundary between the conductive member and the external electrode at the package reliability evaluation test (e.g. share test) or at a substrate's bending due to heat of use.
The color of the sealing material 53 may be selected optionally. Therefore, by adopting the sealing materials 53′ in different colors in sealing up the semiconductor chips, it is also possible to produce the semiconductor devices 51 representing their polarity individually. Needless to say, by adjusting the thicknesses of the resin substrates and the sealing material or the intervals or sizes of the through-holes, it is possible to modify the dimensions of the semiconductor device with ease.
The seventh embodiment of the present invention will be described below. Also in the seventh embodiment, elements identical to those of the first to the fifth embodiments are indicated with the same reference numerals and their overlapping descriptions are eliminated.
The difference between the seventh embodiment and the sixth embodiment resides in the profiles of the external electrodes.
According to the seventh embodiment, a semiconductor device 61 is provided in the form of a substantially-rectangular parallelepiped, as shown in
In the semiconductor device 61 of the seventh embodiment, the plating film 61 has a thickness (length in the longitudinal direction of the device 61) larger than that of the plating film 54 of the previous device 51. This difference in thickness is derived from a difference in profile of the external electrodes 62 (62a, 62b).
As shown in
The first external electrode 62a is formed by a first conductive path 62a1, a second conductive path 62a1 and a pair of third conductive paths 62a3, providing a substantial-T shaped section. These conductive paths are integrated to one body since the external electrode 62 is formed by the plating.
The first conductive path 62a1 corresponding to a center shaft of the T-shaped section has one end connected to the first pole 5a1 on the first surface 5a of the chip 5. The first conductive path 62a1 is provided by applying plating on a through-hole 66aa formed in the first resin substrate 66a. The above-mentioned metal-to-metal joint is realized between the first external electrode 62a and the first pole 5a1 through this plating.
The other end of the first conductive path 62a1 is joined to the second conductive path 62a2. The second conductive path 62a2 has a sectional area larger than that of one end the first conductive path 62a1 connected to the first pole 5a1.
The second conductive path 62a2 is connected, on both sides in the shortitudinal direction of the device 61, with the third conductive paths 62a3 shorter than a longitudinal length of the first conductive path 62a1 (or a depth of the through-hole 66aa). The electrode having five surfaces is provided by forming the plating film 64 on the second conductive path 62a2 and the third conductive paths 62a3.
The manufacturing method of the semiconductor device 61 of the sixth embodiment will be described with reference to
First, a plurality of resin substrates 66 (66a, 66b) are prepared. Preferably, FR-4 or BT resin is available for the material forming the resin substrates 66.
For instance, by means of laser, drill or the like, a plurality of through-holes 66ba, 66aa are formed in the substrates 66b, 66a respectively, at regular intervals. The intervals between the adjoining through-holes 66ba, 66aa are optionally determined in light of the width of a dicing blade used in the later-mentioned dicing process, the position of the semiconductor chip 5 and so on. Also, the diameters of the through-holes 66ba, 66aa are determined corresponding to the required performance of the semiconductor device 61 on the assumption of certain connection with the poles 5b1, 5a1 on the surfaces 5b, 5a of the semiconductor chip 5.
Next, a plurality of through-holes 63a are formed in the sheet-shaped sealing material 63′ at the same pitch as the interval of the through-holes 66ba of the second resin substrate 66b by means of laser, drill or the like. Each of the through-holes 63a is provided for accommodating the semiconductor chip 5 while making its surfaces except for the first and the second surfaces 5a, 5b contact with respective surfaces defining the through-hole 63a. Next, using a laminator device, the so-formed sealing material 63′ is temporarily fixed on the second resin substrate 66b under slight pressure with heat. In fixing, the positioning of the second resin substrate 66b with respect to the sealing material 63′ is accomplished by according a diametral center of each through-hole 66b with a diametral center of the through-hole 63a.
Thereupon, the semiconductor chips 5 are fitted in the through-holes 63a in the sealing material 63′ and successively, the first resin substrate 66a is mounted on the semiconductor chips 5 and the sealing material 63′. In mounting, the first resin substrate 66a is positioned so that the through-holes 66a oppose the through-holes 66ba in the second resin substrate 66b through the semiconductor chips 5, respectively.
At this moment, the first and the second poles 5a1, 5b1 on the first and the second surface 5a, 5b of each semiconductor chip 5 are not obstructed by the first and the second resin substrates 66a, 66b due to the through-holes 66aa, 66ba, respectively.
Citing an example of the first resin substrate 66a, as shown in
The formation of the grooves 66ab, 66bb is directed to easy fabrication of the electrodes each having five surfaces. That is, by forming the grooves 66ab, 66bb in the resin substrates 66, it becomes possible to form the above-mentioned third conductive paths, broadening an area to be coated with the plating films.
Thereafter, the plating is applied on all of the through-holes 66aa, 66ba, the grooves 66ab, 66bb, one surface of the first resin substrate 66a opposed to the other surface in contact with the semiconductor chips 5 and the sealing material 63′ and one surface of the second resin substrate 66b opposed to the other surface in contact with the semiconductor chips 5 and the sealing material 63′, forming the external electrodes 62, as shown in
After completing the plating process, as shown with broken lines of
In the seventh embodiment, the plating films 64 are formed on the first external electrode 62a and the second external electrode 62b by means of barrel plating (not shown). With the adoption of barrel plating, it is possible to allow the external electrodes 62 to be coated with the plating films 64 with ease. In this way, the semiconductor device 61 of
Therefore, also in the seventh embodiment, it is possible to provide a semiconductor device and its manufacturing method both capable of ensuring high reliability while improving its electrical characteristics with the structure requiring no bonding wires and also improving the productivity with raised process yield.
Particularly, by plating the external electrodes, it is possible to produce the metal-to-metal joint in the connection between the poles of the semiconductor chip and the external electrodes. Thus, it is possible to prevent the semiconductor chip from being broken, for example, its breakage originating in one boundary between the semiconductor chip and the conductive member and another boundary between the conductive member and the external electrode at the package reliability evaluation test (e.g. share test) or at a substrate's bending due to heat of use.
Further, with the adoption of barrel plating, there is no need of dipping the semiconductor device in plating liquid, different from the sixth embodiment. Therefore, the deposition of the plating films on the external electrodes can be simplified furthermore, allowing the manufacturing process to be simplified.
The color of the sealing material 73 may be selected optionally. Therefore, by adopting the sealing materials 73 in different colors in sealing up the semiconductor chips, it is also possible to produce the semiconductor devices 71 representing their polarity individually. Needless to say, by adjusting the thicknesses of the resin substrates and the sealing material or the intervals or sizes of the through-holes, it is possible to modify the dimensions of the semiconductor device with ease.
As is clear from the above description, the present invention will become more fully apparent from the following description and appended claims taken in conjunction with the accompany drawings.
Although the present invention has been described above by reference to seven embodiments of the invention, this invention is not limited to these embodiments and modifications will occur to those skilled in the art, in light of the teachings. Further, various inventions may be made by combining a variety of constituents disclosed in the embodiments with each other appropriately. For example, some constituents may be removed from the whole constituents in the embodiments. Moreover, constituents in one embodiment may be combined with a semiconductor device of the other embodiment appropriately. The scope of the invention is defined with reference to the following claims.
This application is based upon the Japanese Patent Applications No. 2007-245852, filed on Sep. 21, 2007, the entire content of which is incorporated by reference herein.
Number | Date | Country | Kind |
---|---|---|---|
2007-058564 | Mar 2007 | JP | national |
2007-245852 | Sep 2007 | JP | national |