The present application claims priorities to Chinese Patent Application No. 201610351529.7, titled “PACKAGING METHOD AND PACKAGING STRUCTURE FOR SEMICONDUCTOR CHIP”, filed on May 25, 2016 with the Chinese Patent Office, and Chinese Patent Application No. 201620484861.6, titled “PACKAGING STRUCTURE FOR SEMICONDUCTOR CHIP”, filed on May 25, 2016 with the Chinese Patent Office, both of which are incorporated herein by reference in their entireties.
The present disclosure relates to the technical field of semiconductors, and in particular to a wafer level semiconductor chip packaging technology
Currently, the wafer level chip size packaging (WLCSP) technology is the mainstream semiconductor chip packaging technology, in which a full wafer is packaged and tested, and then is cut to acquire individual finished chips. By using this packaging technology, the packaged individual finished chip almost has the same size as an individual crystalline grain, which meets the market requirement for lighter, smaller, shorter, thinner and cheaper microelectronic products. The wafer level chip size packaging technology is a hotspot in the current packaging field and represents a development trend in the future.
The wafer includes multiple semiconductor chips. One surface of the semiconductor chip is arranged with a functional region and contact pads, the contact pads are located on the periphery of the functional region and electrically connected to the functional region. In order to protect the functional region, a protective substrate is laminated with the wafer, and the protective substrate is provided with support units. Since the support unit is in contact with the wafer at a position corresponding to each of the contact pads and the thermal expansion coefficient of the support unit is different from that of the wafer, the support unit may generate a stress acting on the contact pad during a reliability test, which may easily cause a damage to the contact pad. In particular, in a case that the contact pad has a multi-layer structure, the stress may easily cause delamination of the contact pad.
A wafer level semiconductor chip packaging method and a semiconductor chip package are provided according to the present disclosure, to solve the problem that the contact pad may be damaged, so as to improve the quality and reliability of the semiconductor chip package.
In order to solve the above problem, a semiconductor chip packaging method is provided according to the present disclosure, which includes:
In an embodiment, the multiple semiconductor chips are arranged in a grid. The multiple support units are located in one-to-one correspondence with the multiple semiconductor chips. In addition/Alternatively, the functional region of each of the multiple semiconductor chips is located in a sealed cavity formed by surrounding the support unit corresponding to the semiconductor chip.
In an embodiment, before the laminating the wafer with the protective substrate, the method further includes:
In an embodiment, the support unit is made of photosensitive glue, and the support unit and the openings in the support unit are simultaneously formed by an exposure development process.
In an embodiment, the multiple support units are arranged in a grid, and the openings are formed by a laser drilling process after the multiple support units arranged in a grid are formed.
In an embodiment, after the laminating the wafer with the protective substrate, the method further includes:
In an embodiment, the solder resist layer is formed by a spray coating process, and the sidewall and the bottom of the through hole are uniformly covered by the solder resist layer.
In an embodiment, the solder resist layer is formed on the second surface of the wafer and in each of the multiple through holes by a spin coating process. The groove is formed on the solder resist layer at the position corresponding to the through hole by an etching process or a laser drilling process.
In an embodiment, a difference between a depth of the groove and a depth of the through hole arranges from 0 to 20 micrometers, and the solder resist layer is made of photosensitive glue.
In an embodiment, after the laminating the wafer with the protective substrate, the method further includes:
In an embodiment, the solder resist layer is formed by a spin coating process, and a viscosity of the solder resist layer is greater than 12 Kcps.
In an embodiment, the semiconductor chip is an image sensor chip, and the functional region is arranged with a photosensitive element.
A semiconductor chip package is further provided according to the present disclosure, which includes: a substrate having a first surface and a second surface opposite to each other; a functional region and contact pads arranged on the first surface of the substrate; a protective substrate arranged on the first surface of the substrate; and a support unit arranged between the protective substrate and the substrate. The functional region is arranged in a sealed cavity formed by surrounding the support unit. The support unit is provided with openings, such that the first surface of the wafer is not in contact with the support unit at a position corresponding to each of the contact pads.
In an embodiment, the support unit is made of photosensitive glue.
In an embodiment, the package further includes:
In an embodiment, the sidewall and the bottom of each of the through holes are covered by the solder resist layer.
In an embodiment, a difference between a depth of the groove and a depth of the through hole arranges from 0 to 20 micrometers, and the solder resist layer is made of photosensitive glue.
In an embodiment, the semiconductor chip package further includes:
In an embodiment, a viscosity of the solder resist layer is greater than 12 Kcps.
In an embodiment, the semiconductor chip is an image sensor chip, and the functional region is arranged with a photosensitive element.
According to the present disclosure, the following beneficial effect can be achieved. The support unit is provided with openings, such that the wafer is not in contact with the support unit at a position corresponding to each of the contact pads, thereby effectively preventing the support unit from generating a stress acting on the contact pad in a subsequent reliability test, thus avoiding a damage to the contact pad or delamination of the contact pad. In this way, the packaging yield of the semiconductor chip is improved and the reliability of the semiconductor chip package is also improved.
The embodiments of the present disclosure are described in detail below in conjunction with the drawings. However, the embodiments are not intended to limit the present disclosure, and any changes in structures, methods or functions made by those skilled in the art based on the embodiments fall within the protection scope of the present disclosure.
Generally, the semiconductor chip is integrated with sensitive elements, and it is required to protect the sensitive elements on the semiconductor chip during the semiconductor chip is packaged. Referring to
Since the contact pad 12 and the functional region 11 are located on the first surface of the wafer 1, in order to implement an electrical connection between the contact pad 12 and an external circuit, a solder bump 25 electrically connected to the contact pad 12 is formed on the second surface of the wafer 1 by TSV or TSL process after the wafer 1 is aligned and laminated with the protective substrate 2, and the electrical connection between the contact pad 12 and the external circuit may be implemented. by electrically connecting the solder hump 25 to the external circuit.
In order to implement the electrical connection between the contact pad 12 and the external circuit, through holes 22 extending toward the first surface of the water 1 are arranged on the second surface of the wafer 1. The through holes 22 are located in one-to-one correspondence with the contact pads 12, and each of the contact pads 12 is exposed from a bottom of one through hole 22. An insulating layer 23 is arranged on a sidewall of each of the through holes 22 and the second surface of the wafer 1. A metal wiring layer 24 is arranged on the insulating layer 23 and the bottom of each of the through holes 22. The metal wiring layer 24 is electrically connected to the contact pads 12. Solder bumps 25 are arranged on the second surface of the wafer, and the solder bumps 25 are electrically connected to the metal wiring layer 24. The second surface of the wafer 1 is arranged with cutting trenches 21 extending toward the first surface of the wafer 1, to facilitate cutting off the packaged sensor chip tin an example, the sensor chip is an image sensor chip).
Since the thermal expansion coefficient of the support unit 3 is different from that of the wafer 1, the support unit 3 may generate a stress acting on the contact pad 12 in the subsequent reliability test, which may cause a damage to the contact pad 12. In particular, in a case that the contact pad 12 has a multi-layer structure, the stress of the support unit 3 acting on the contact pad 12 may cause delamination of the contact pad 12.
In order to solve the problem of the damage to the contact pad and/or the delamination of the contact pad, in the embodiment of the present disclosure, the support unit is provided with openings, such that the wafer is not in contact with the support unit at a position corresponding to each of the contact pads, thereby effectively preventing the support unit from generating a stress acting on the contact pad in a subsequent reliability test, thus avoiding the damage to the contact pad or the delamination of the contact pad. In this way, the packaging yield of the semiconductor chip is improved and the reliability of the semiconductor chip package is also improved.
Reference is made to
Each of the semiconductor chips 110 includes a functional region 111 and multiple contact pads 112. The contact pads are arranged on the periphery of the functional region 111. In addition, the contact pads 112 and the functional region 111 are arranged on the same surface of the wafer 100.
Reference is made to
The wafer 100 has a first surface 101 and a second surface 102 opposite to each other. The functional region 111 and the contact pads 112 are arranged on the first surface 101 of the wafer 100. The second surface 102 of the wafer is arranged with cutting trenches 103 and through holes 113. The cutting trench 103 and the through hole 113 are extended toward the first surface 101. Each of the through holes 113 corresponds to one contact pad 112 in terms of position, and the contact pad 112 is exposed from the bottom of the through hole 113.
The electrical connection between the contact pad 112 and the external circuit is implemented via the metal wiring layer 115 and the solder bump 116. Specifically, an insulating layer 114 is arranged on the sidewall of the through hole 113 and the second surface 102 of the wafer 100, a metal wiring layer 115 electrically connected to the contact pads 112 is formed at the bottom of each of the through holes 113 and on the sidewall of each of the through holes 113. The metal wiring layer 115 is extended to the second surface 102 of the wafer 100. The metal wiring layer 115 is arranged on the insulating layer 114, and a solder resist layer 117 is arranged on the metal wiring layer 115. The solder resist layer 117 covers the second surface 102 of the wafer 100 and fills the cutting trenches 103 and the through holes 113. The solder resist layer 117 is provided with openings, and the metal wiring layer 115 is exposed from the bottom of each of the openings. The solder bump 116 is arranged in each of the openings and is electrically connected to the metal wiring layer 115. The electrical connection between the contact pad 112 and the external circuit is implemented by electrically connecting the solder bump 116 to the external circuit.
The support unit 210 is provided with openings 211, such that the wafer 100 is not in contact with the support unit 210 at a position corresponding to each of the contact pads 112, thereby effectively preventing the support unit 210 from generating a stress acting on the contact pad 112 in a subsequent reliability test, thus avoiding a. damage to the contact pad 112 or delamination of the contact pad 112. In this way, the packaging yield of the semiconductor chip is improved and the reliability of the semiconductor chip package is also improved.
A packaging process for forming a semiconductor chip package as shown in
The wafer 100 is provided. Reference may he made to
The protective substrate 200 is provided. One surface of the protective substrate 200 is arranged with the multiple support units 210 in a grid. In the embodiment, the support unit 210 is made of photosensitive glue. The support units 210 and the openings 211 are simultaneously formed on the surface of the protective substrate 200 by coating the entire surface of the protective substrate 200 with the photosensitive glue and then using an exposure development process.
Alternatively, the support units 210 arranged in a grid and the openings 211 are simultaneously formed on one surface of the protective substrate 200 by a screen printing process.
Alternatively, the support units 210 are first formed by an exposure development process, and the opening 211 is formed on the support unit 210 at a position corresponding to each of the contact pads 112 by a laser drilling process.
Alternatively, the support units 210 are first formed by a screen printing process, and the opening 211 is formed on the support unit 210 at a position corresponding to each of the contact pads 112 by a laser drilling process.
Referring to
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In another embodiment of the present disclosure, the through holes 113 may be first formed and then the cutting trenches 103 are formed.
Referring to
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Preferably, a thickness of the solder resist layer 117′ ranges from 5 micrometers to 20 micrometers.
However, the groove may be formed on the solder resist layer 117 at the position corresponding to each of the through holes 113 by an etching process or a laser drilling process after the spraying process shown in
The difference between the depth of the groove (for example, the groove and the depth of the through hole 113 ranges from 0 to 20 micrometers.
Referring to
Preferably, a viscosity of the solder resist layer 117″ is greater than 12 Kcps.
Preferably, in order to form the cavity 119 in the through hole 113, it is required to increase the rate of spin coating process. In order to fill the cutting trench 103 with the soldering layer 117″, the sidewall of the cutting trench 103 is arranged to be an inclined surface to facilitate the filling of the solder resist layer 117″.
In the embodiment, the solder resist layers 117, 117′ and/or 117″ may be made of photosensitive glue.
Referring to
Referring to
Finally, the wafer 100 and the protective substrate 200 are cut from the second surface 102 of the wafer 100 towards the first surface 101 of the wafer 100 along the cutting trenches 103 to acquire individual semiconductor chip packages.
Referring to
The support unit 210 is provided with openings 211, such that the substrate 310 is not in contact with the support unit 210 at a position corresponding to each of the contact pads 112, thereby effectively preventing the support unit 210 from generating a stress acting on the contact pad 112 in a subsequent reliability test, thus preventing a damage to the contact pad 112 or delamination of the contact pad 112. In this way, the packaging yield of the semiconductor chip is improved and the reliability of the semiconductor chip package is also improved.
The semiconductor chip in the embodiment may be an image sensor chip, and the functional region is arranged with a photosensitive element. However, the semiconductor chip in the embodiment of the present disclosure is not limited to the image sensor chip.
According to the present disclosure, the following beneficial effect can be achieved. The support unit is provided with openings, such that the wafer is not in contact with the support unit at a position corresponding to each of the contact pads, thereby effectively preventing the support unit from generating a stress acting on the contact pad in a subsequent reliability test, thus avoiding a damage to the contact pad or delamination of the contact pad. In this way, the packaging yield of the semiconductor chip is improved and the reliability of the semiconductor chip package is also improved.
It is to be understood that although the specification is described according to the embodiments, not each of the embodiments includes only one independent technical solution. The description of the specification is merely for the sake of clarity and those skilled in the art should take the specification as a whole, and the technical solutions in the embodiments may also be appropriately combined to form other embodiments that can be understood by those skilled in the art.
A series of detailed description above merely illustrates the feasible embodiments of the present disclosure, and is not intended to limit the protection scope of the present disclosure. Any equivalent embodiment or variation made without departing from the technical spirit of the present disclosure should fall within the protection scope of the present disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201610351529.7 | May 2016 | CN | national |
| 201620484861.6 | May 2016 | CN | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2017/084862 | 5/18/2017 | WO | 00 |