CHIP PACKAGE AND CHIP PACKAGING METHOD
20180366387 ยท 2018-12-20
Assignee
Inventors
Cpc classification
H01L2224/13024
ELECTRICITY
H01L2224/0401
ELECTRICITY
H01L21/78
ELECTRICITY
H01L2221/6834
ELECTRICITY
H01L2224/12105
ELECTRICITY
H01L2924/00014
ELECTRICITY
H01L2224/131
ELECTRICITY
H01L21/76877
ELECTRICITY
H01L2221/68381
ELECTRICITY
H01L2224/113
ELECTRICITY
H01L2224/13025
ELECTRICITY
H01L2224/05548
ELECTRICITY
H01L2224/95001
ELECTRICITY
H01L2924/00014
ELECTRICITY
H01L21/568
ELECTRICITY
H01L2224/94
ELECTRICITY
H01L2224/1148
ELECTRICITY
H01L2224/131
ELECTRICITY
H01L24/96
ELECTRICITY
H01L21/76816
ELECTRICITY
H01L2224/13022
ELECTRICITY
H01L2224/02371
ELECTRICITY
H01L2224/94
ELECTRICITY
International classification
H01L21/768
ELECTRICITY
H01L21/78
ELECTRICITY
Abstract
A chip package and a chip packaging method are provided. The package includes: a chip to be packaged, a reinforcing layer and solder bumps. The chip to be packaged includes a first surface and a second surface opposite to each other, the first surface includes a sensing region and first contact pads, and the first contact pads are electrically coupled to the sensing region. The reinforcing layer covers the first surface of the chip to be packaged. The solder bumps are provided on the second surface of the chip to be packaged. The solder bump is electrically connected to the first contact pad and is configured to electrically connect with an external circuit.
Claims
1. A chip package, comprising: a chip to be packaged, wherein the chip to be packaged comprises a first surface and a second surface opposite to each other, the first surface comprises a sensing region and first contact pads, and the first contact pads are electrically coupled to the sensing region; a reinforcing layer covering the first surface of the chip to be packaged; and solder bumps provided on the second surface of the chip to be packaged, wherein the solder bump is electrically connected to the first contact pad and is configured to electrically connect with an external circuit.
2. The chip package according to claim 1, wherein hardness of the reinforcing layer is greater than 6H.
3. The chip package according to claim 1, wherein the reinforcing layer is made of an organic material or an inorganic material.
4. The chip package according to claim 1, wherein the chip to be packaged is a capacitive sensing chip, a dielectric constant of the reinforcing layer is greater than 3, and the reinforcing layer is made of an insulating material.
5. The chip package according to claim 1, wherein the chip to be packaged is a photosensitive chip, and the reinforcing layer is made of a transparent material.
6. The chip package according to claim 5, wherein a light transmittance of the reinforcing layer is greater than 80%.
7. The chip package according to claim 1, wherein a thickness of the reinforcing layer ranges from 2 m to 40 m, inclusive.
8. The chip package according to claim 1, further comprising: a strengthening layer provided on a side of the chip to be packaged facing away from the reinforcing layer, wherein the strengthening layer is located on the outermost side of the package.
9. The chip package according to claim 8, wherein the strengthening layer is made of a plastic packaging adhesive.
10. The chip package according to claim 1, wherein the second surface of the chip to be packaged is provided with via holes penetrating the chip to be packaged, the via hole is configured to expose the first contact pad; and the solder bump is electrically connected to the first contact pad through a rewiring layer provided in the via holes.
11. The chip package according to claim 10, wherein the via hole is a double-stepped hole configured to expose the first contact pad; and each of the via holes comprises: a groove provided on the second surface of the chip to be packaged, wherein a depth of the groove is less than a thickness of the chip to be packaged; and a through hole located in the groove and penetrating the chip to be packaged, wherein there is a one-to-one correspondence between the through holes and the first contact pads, and the through hole is configured to expose the corresponding first contact pad.
12. The chip package according to claim 10, wherein the via hole is an inverted trapezoid hole configured to expose the first contact pad; and an aperture of the via hole gradually increases in a direction from the first surface to the second surface.
13. The chip package according to claim 10, wherein the via hole is a straight hole configured to expose the first contact pad.
14. The chip package according to claim 1, wherein a sidewall of the chip to be packaged comprises an inclined cutting plane, the second surface is smaller than the first surface due to the inclined cutting plane, to expose a portion of the first contact pad; and the solder bump is electrically connected to the first contact pad through a rewiring layer provided on the inclined cutting plane.
15. A chip packaging method, comprising: providing a wafer, wherein the wafer comprises a plurality of chips to be packaged arranged in an array, each of the chips to be packaged comprises a first surface and a second surface opposite to each other, the first surface comprises a sensing region and first contact pads, the first contact pads are electorically coupled to the sensing region, first surfaces of the plurality of the chips to be packaged are located on a same side of the wafer; forming a reinforcing layer on a surface of the wafer, wherein the reinforcing layer covers the first surfaces of the plurality of chips to be packaged; laminating and fixing the reinforcing layer to a protection substrate; forming solder bumps on the other surface of the wafer, wherein a second surface of each of the chips to be packaged is provided with the solder bump, the solder bump is electrically connected to the first contact pad and is configured to electrically connect with an external circuit; cutting the wafer and the reinforcing layer with a cutting process, to form packages of the plurality of chips to be packaged; and peeling off the protection substrate.
16. The chip packaging method according to claim 15, wherein the laminating and fixing the reinforcing layer to the protection substrate comprises: laminating and fixing the reinforcing layer to the protection substrate by using a UV adhesive.
17. The packaging method according to claim 15, wherein before performing the cutting process, the method further comprises: forming a strengthening layer on a side of the wafer facing away from the reinforcing layer, wherein the strengthening layer is located on the outermost side of the package.
18. The chip packaging method according to claim 15, wherein the forming the solder bump on the other surface of the wafer comprises: forming via holes penetrating the wafer on the second surface of each of the chips to be packaged, wherein the via hole is configured to expose the first contact pad; forming an insulating layer covering the second surface of the chip to be packaged and a sidewall of the via hole, wherein the insulating layer is configured to expose the first contact pad; forming a rewiring layer covering a bottom of the via hole and the insulating layer; and forming the solder bump on a surface of the rewiring layer, wherein the solder bump is provided opposite to the sensing region of the chip to be packaged.
19. The chip packaging method according to claim 18, wherein the forming the via holes penetrating the wafer on the second surface of each of the chips to be packaged comprises: forming double-stepped holes configured to expose the first contact pads on the second surface of the chip to be packaged, wherein each of the via holes comprises: a groove provided on the second surface of the chip to be packaged, a depth of the groove being less than a thickness of the chip to be packaged, and a through hole located in the groove and penetrating the chip to be packaged, there being a one-to-one correspondence between the through holes and the first contact pads, and the through hole being configured to expose the corresponding first contact pad; forming inverted trapezoid holes configured to expose the first contact pads on the second surface of the chip to be package, wherein an aperture of the via hole gradually increases in a direction from the first surface to the second surface; or forming straight holes configured to expose the first contact pads on the second surface of the chip to be packaged.
20. The chip packaging method according to claim 15, wherein the forming the solder bump on the other surface of the wafer comprises: forming an inclined cutting plane on a sidewall of the chip to be packaged, wherein the second surface is smaller than the first surface due to the inclined cutting plane, to expose the first contact pads; forming an insulating layer covering the inclined cutting plane and the second surface of the chip to be packaged, wherein the insulating layer is configured to expose the first contact pads; forming a rewiring layer covering the first contact pads and the insulating layer; and forming the solder bumps on a surface of the rewiring layer, wherein the solder bumps are provided opposite to the sensing region of the chip to be packaged.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0060] In order to more clearly describe the technical solution in the embodiments of the present disclosure or the technical solution in the conventional technology, drawings to be used in the embodiments of the present disclosure or in the conventional technology are briefly described hereinafter. It is apparent that the drawings described below show merely the embodiments of the present disclosure, and those skilled in the art may obtain other drawings from the drawings without any creative effort.
[0061]
[0062]
[0063]
[0064]
[0065]
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DETAILED DESCRIPTION OF EMBODIMENTS
[0068] The technical solution in the embodiments of the present disclosure is described clearly and completely hereinafter in conjunction with the accompanying drawings in the embodiments of the present disclosure. Apparently, the described embodiments are merely a part rather than all of embodiments of the present disclosure. All other embodiments obtained by those skilled in the art based on the embodiments of the present disclosure without any creative effort fall within the protection scope of the present disclosure.
[0069] It should be noted that these drawings are provided for the purpose of aiding understanding of the embodiments of the present disclosure and should not be construed as limiting the present disclosure. For the sake of clarity, the dimensions shown in the drawings are not drawn to scale and may be enlarged, reduced, or altered in other way. In addition, three-dimensional space sizes of a length, a width and a depth should be included in an actual production. Furthermore, a structure described below that a first feature is on a second feature may include an embodiment in which the first feature and the second feature are in direct contact and may further include an embodiment in which an additional feature is formed between the first feature and the second feature, and in the latter case, the first and second features may not be in direct contact.
[0070] To make the foregoing objects, features and advantages of the present disclosure clearer and more comprehensible, the present disclosure is further described in detail below in conjunction with the accompanying drawings and specific embodiments.
[0071] Reference is made to
[0072] The first surface includes a sensing region A and first contact pads 200, and the first contact pads 200 are electrically coupled to the sensing region A. The first contact pads 200 are provided in a packaging region B surrounding the sensing region A. The solder bump 127 is electrically connected to the first contact pad 200 and is configured to electrically connect with an external circuit.
[0073] Hardness of the reinforcing layer 30 is greater than 6H. In the package according to the embodiment of the present disclosure, the reinforcing layer 30 with hardness greater than 6H is provided on the first surface of the chip to be packaged 10, so that the package has high hardness and great mechanical strength.
[0074] The reinforcing layer 30 may be made of an organic material or an inorganic material. For example, the reinforcing layer 30 may be made of a hardened silica gel. A cured silica gel has good temperature resistance, weather resistance and electrical insulation property, thereby ensuring that the package has a long service life.
[0075] The sensing region of the chip to be packaged 10 is provided with multiple pixels 100 arranged in an array. The chip to be packaged 10 may be a capacitive sensing chip, for example, a fingerprint identification chip. In this case, a dielectric constant of the reinforcing layer 30 is greater than 3, the reinforcing layer 30 is made of an insulating material, and fingerprint information is identified in response to a change in capacitance caused by a finger touch. In this way, when the finger touches the reinforcing layer 30 on the surface of the sensing region A, the pixel 100 is used to identify the fingerprint information in response to the change in capacitance.
[0076] In other embodiments, the chip to be packaged 10 may also be a photosensitive chip. In this case, in order to facilitate sensing light by the pixel 100, the reinforcing layer 30 may be made of a transparent material. In this case, the chip to be packaged 10 may be an image sensing chip. The pixel 100 is used to sense incident light through the transparent reinforcing layer 30, and generate image information based on the optical information. In the case where the chip to be packaged 10 is a photosensitive chip, a light transmittance of the reinforcing layer 30 is set to be greater than 80% in order to ensure imaging quality.
[0077] In order to ensure a good sealing effect of the reinforcing layer, a thickness of the reinforcing layer 30 is set to range from 2 m to 40 m, inclusive, to effectively isolate water vapor and protect the pixel 100.
[0078] Generally, in order to obtain a thin package, the second surface of the chip to be packaged 10 is thinned when the chip to be packaged 10 is packaged. Specifically, the second surface of the chip to be packaged 10 may be thinned with mechanical grinding, chemical etching or other ways. However, mechanical strength of the thinned chip to be packaged 10 is weak. In order to further enhance the mechanical strength of the package, the package further includes a strengthening layer provided on a side of the chip to be packaged 10 facing away from the reinforcing layer 30, and the strengthening layer is located on the outermost side of the package. The strengthening layer is not shown in
[0079] In the package according to the embodiment of the present disclosure, the mechanical strength of the strengthening layer is greater than strength of a substrate of the chip to be packaged 10. The thickness of the chip to be packaged 10 can be further reduced with the thinning process and the mechanical strength can be enhanced by the strengthening layer. Therefore, the thickness of the chip to be packaged 10 can be reduced while good mechanical strength of the package is ensured. That is, compared with the package in the conventional technology, in the package according to the embodiment of the present disclosure, the thickness of the chip to be packaged 10 can be further reduced with the thinning process, so that the thickness of the chip to be packaged 10 is smaller, and the mechanical strength of the thinned chip to be packaged is compensated by a strengthening layer with better mechanical strength. Therefore, the thin and light package is implemented. Optionally, the strengthening layer may be made of a plastic packaging adhesive.
[0080] The second surface of the chip to be packaged 10 is provided with via holes penetrating the chip to be packaged 10, and the via holes are configured to expose the first contact pads 200, so that the solder bump 127 can be electrically connected to the first contact pad 200.
[0081] In the embodiment shown in
[0082] As shown in
[0083] An insulating layer 123 is further provided between the rewiring layer 124 and the chip to be packaged 10. The insulating layer 123 covers a sidewall of the via hole and exposes a bottom of the via hole, such that the rewiring layer 124 is electrically connected to the first contact pad 200. The rewiring layer 124 covers the bottom of the via hole and the insulating layer 123. The solder bump 127 is located on the surface of the insulating layer 123. Specifically, a solder mask 125 is further provided on the surface of the rewiring layer 124. A surface of the solder mask 125 is provided with openings to accommodate the solder bumps 127, such that the solder bump 127 is electrically connected to the rewiring layer 124 at the opening.
[0084] Reference is made to
[0085] Reference is made to
[0086] In the packages shown in
[0087] Reference is made to
[0088] It can be seen from the above description that in the package according to the embodiment of the present disclosure, the reinforcing layer 30 is provided on the first surface of the chip to be packaged 10, the solder bumps 127 are provided on the second surface, and the solder bump 127 is electrically connected to the first contact pad 200 on the first surface so as to electrically connect with an external circuit. During a process of forming the package, the reinforcing layer 30 is provided on the first surface of the chip to be packaged 10, therefore, the surface of the chip to be packaged 10 can be prevented from being damaged and contaminated during the cutting process performed after the protection substrate is removed, and the strength of the structure to be packaged can be enhanced due to the reinforcing layer 30.
[0089] Based on the package described in the above-described embodiment, a packaging method is further provided according to another embodiment of the present disclosure, as shown in
[0090] In step S11, as shown in
[0091]
[0092] Each of the chips to be packaged 10 includes a first surface and a second surface opposite to each other. The first surface includes a sensing region A and a packaging region B surrounding the sensing region A. The packaging region B includes first contact pads 200 for circuit interconnection, and the first contact pads 200 are electrically coupled to the sensing region A. The first surfaces of all the chips to be packaged are located on a same side of the wafer 21. In the embodiment of the present disclosure, the first contact pad 200 being electrically coupled to the sensing region A indicates that the first contact pad 200 is electrically connected to multiple electrical devices in the sensing region A.
[0093] In step S12, as shown in
[0094] The reinforcing layer 30 may be formed with a molding process in a semiconductor packaging process.
[0095] In step S13, as shown in
[0096] In step S13, the process of laminating and fixing the reinforcing layer 30 to the protection substrate 20 includes: laminating and fixing the reinforcing layer 30 to the protection substrate 20 by using a UV adhesive 31, where the UV adhesive 31 can be peeled off from the reinforcing layer 30 subsequently. The reinforcing layer 30 is fixed to the protection substrate by using the UV adhesive 31 with UV light sensitivity as a temporary bonding layer. In a case where the UV light irradiates the UV adhesive 31 through the protection substrate 20, the UV adhesive 31 loses viscosity so that the reinforcing layer 30 is separated from the protection substrate 20.
[0097] In step S14, solder bumps are formed on the other surface of the wafer.
[0098] The second surface of each of the chips to be packaged is provided with a solder bump, and the solder bump is electrically connected to the first contact pad and is configured to electrically connect with an external circuit.
[0099] In step S14, the process of forming the solder bumps on the other surface of the wafer includes the following steps.
[0100] First, a via hole penetrating the wafer is formed on a second surface of each chip to be packaged, and the via hole is configured to expose the first contact pad. The forming of the package shown in
[0101] Further, as shown in
[0102] Further, as shown in
[0103] Finally, as shown in
[0104] In step S15, as shown in
[0105] In step S16, as shown in
[0106] For the embodiment shown in
[0107] In other embodiments, the process of forming the via hole penetrating the wafer on the second surface of each of the chips to be packaged includes: forming an inverted trapezoid hole configured to expose the first contact pad on the second surface of the chip to be packaged. An aperture of the via hole gradually increases in a direction from the first surface to the second surface. The via hole may be a truncated cone or a frustum of a prism. In this case, the package shown in
[0108] In other embodiments, the process of forming the via hole penetrating the wafer on the second surface of each of the chips to be packaged includes: forming a straight hole configured to expose the first contact pad on the second surface of the chip to be packaged. An aperture of the via hole remains unchanged in a direction from the first surface to the second surface. The via hole may be a round hole, a triangular hole, a square hole or the like. In this case, the package shown in
[0109] In the embodiment shown in
[0110] First, as shown in
[0111] Then, as shown in
[0112] Further, as shown in
[0113] Finally, as shown in
[0114] In order to further enhance the mechanical strength of the package, the packaging method according to the embodiment of the present disclosure further includes: forming a strengthening layer on a side of the wafer facing away from the reinforcing layer. Specifically, the strengthening layer may be located between the chip to be packaged and the insulating layer, or cover the solder mask and is located on an outer surface of the package.
[0115] It can be seen from the above description that the package described in the above-described embodiment can be formed with the packaging method according to the embodiment of the present disclosure, the packaging process is simple, the manufacturing cost is low, and the formed package has strong mechanical strength.
[0116] The embodiments in the present specification are described in a progressive manner. Each embodiment focuses on differences from other embodiments, and for the same or similar parts among the embodiments, one may refer to description of other embodiments. For the packaging method disclosed in the embodiment, since the packaging method corresponds to the package disclosed in the embodiment, the packaging method is described simply. For the relevant part, reference may be made to the corresponding part of the package.
[0117] The above description of the disclosed embodiments enables those skilled in the art to implement or use the disclosure. Various modifications to these embodiments are readily apparent to those skilled in the art, and the general principles defined herein may be embodied in other embodiments without departing from the spirit or scope of the disclosure. Therefore, the present disclosure should not be limited to these embodiments shown herein, but rather should be in accordance with the broadest scope consistent with the principles and novel features disclosed herein.