TW202234642A - Package on package device and packaging method thereof - Google Patents

Abstract

The present invention is related to a package on package (POP) device and packaging method thereof. The POP device has a first package, a second package and a plurality of metal pillars. The second package is stacked on the first package. One ends of the metal pillars are inserted in the first package and other ends of the metal pillars protrudes out of the first package and are towards the second package. Therefore, the protruding ends of the metal pillars are soldered with the corresponding solder balls of the second package and the first package and the second package are separated accordingly. The metal pillars are formed simultaneously with the first package, so that the through holes for the metal pillars are not laser-formed through the encapsulation of the first package. Therefore, the metal pillars are accurately soldered with the solder balls of the second package to enhance the accuracy of mounting the first encapsulation with the second encapsulation. The smaller POP device is easily fabricated.

Description

Stacked package structure and method of making the same

The present invention relates to a semiconductor packaging structure, especially a stacked packaging structure.

Package On Package (POP) is a 3D package structure, that is, a package body in which different functional chips are individually packaged in advance, and then a package structure formed by three-dimensional stacking and electrical connection with each other. The different electrical connection methods used can be further classified into different package-on-package structures such as Ball Grid Array (BGA), Through Mold Via (TMV), and Through Silicon Via (TSV).

As shown in FIG. 4 , a ball grid array stack package 60 includes an upper package body 61 and a lower package body 62 ; wherein a plurality of first solder balls 611 arranged in a matrix are formed on the bottom surface of the upper package body 61 , and the lower package body 61 The body 62 uses a larger substrate 624 to match the upper package body 61 . The upper surface of the substrate 624 is formed with pads 622 corresponding to the first solder balls 611 on the periphery of the encapsulant body 623 for the first solder balls. 611 is soldered, and a plurality of second solder balls 621 are formed on the lower surface of the substrate 624 for soldering with a circuit board 70 . Since the pads 622 of the lower package 62 are directly formed on the substrate 624, the first solder balls 611 of the upper package 61 can be directly soldered, and the electrical connection structure between the upper and lower packages 61 and 62 is simple. A ball grid array package-on-package 60 is easy to manufacture and is often used; however, with the development of chips with high bulk density, taking the package of a memory module as an example, under the same size, if a ball grid array package-on-package is used 60. The upper package body 61 must increase the density of the first solder balls 611, but the size of the solder balls is not easy to shrink; therefore, it is difficult for the upper package body 61 to continue to increase the solder balls in the same area.

As shown in FIG. 5 , a through-mold through-mold package 80 includes two upper and lower packages 82 and 81 of the same size; wherein the encapsulant 812 of the lower package 81 encapsulates a chip 813 and a plurality of pads together. 811, and then the encapsulation body 812 is laser perforated to expose the pads 811. Since the pads 811 correspond to the solder balls 821 on the bottom surface of the upper package body 82, the upper package body 82 can be directly soldered to the exposed surface with the solder balls 821. on the pad 811. However, the pads 811 are encapsulated in the encapsulant 812, and the laser alignment is difficult. When the alignment is inaccurate or fails, the pads 811 will be abnormal, and the lower and upper encapsulation bodies 81 cannot be smoothly aligned. Electrical connection to 82 is also not optimal for package-on-package.

As for the TSV stack package, it is completely different from the two previous stack packages. Different functional chips are not packaged into packages in advance and then stacked and connected to each other. Instead, the stacked chips are directly drilled, and then the holes are drilled. The conductive material is filled in the middle, so that the upper and lower stacked chips are directly connected; finally, the chips are covered with an encapsulant; therefore, the size of the TSV-on-chip package is smaller than that of the previous peel-on-chip package; however, the current TSV The technical process is relatively complex, the packaging cost is high and the yield rate is not high; therefore, it is necessary to improve the existing package-on-package structure.

In view of the above-mentioned problems of the existing package-on-package structure, the main purpose of the present invention is to provide an improved package-on-package structure.

The main technical means used to achieve the object of the above invention is to make the package-on-package structure include: A first package, comprising: a first substrate, the bottom surface of which forms a plurality of first solder balls with a first pitch; at least one first chip is disposed and electrically connected to the first substrate; a plurality of metal pillars, a first end of each of the metal pillars is disposed at a third interval and electrically connected to the first substrate; and A first encapsulant is formed on the first substrate and covers the at least one first chip and the metal pillars, wherein a second end of each of the metal pillars opposite to the first end is connected from the The top surface of the first colloid protrudes; and A second package, comprising: a second substrate, the bottom surface of which is formed with a plurality of second solder balls at a second interval, and each of the second solder balls is welded and covers the second end of the first package body corresponding to the metal column; wherein the The bottom surface of the second substrate and the top surface of the first encapsulant of the first package body have a first gap, and the second distance matches the third distance; at least one second chip disposed and electrically connected to the second substrate; and A second encapsulant is formed on the second substrate and covers the at least one second chip.

The advantage of the present invention is that the first package body has a plurality of metal pillars, and each of the metal pillars is electrically connected to the first substrate and protrudes from the top surface of the first package body, which is easy to correspond to the second package body The second solder balls are aligned and then soldered, and the protruding parts of the metal pillars are covered by the second solder balls, which improves the accuracy of bonding the first package body and the second package body and the stability of the electrical connection, and improves the stability of the electrical connection. The manufacturing yield of the package-on-package structure.

The main technical means used to achieve the purpose of the above invention is that the manufacturing method of the package-on-package structure includes: (a) disposing at least one chip and a plurality of metal pillars on a substrate, wherein the first end of each of the metal pillars is disposed on the substrate; (b) fixing the substrate, the at least one chip and the metal pillars thereon in a first mold, and disposing a jig in a second mold, on the surface of the jig facing the first mold forming an adhesive film, the adhesive film has a thickness; (c) Covering the first mold and the second mold to form a glue injection space, wherein the second end of the metal posts opposite to the first end faces the fixture and penetrates through the plastic film and abuts against the jig. on the surface of the fixture; (d) filling the glue injection space with a liquid glue material to cover the at least one chip and part of the metal pillars; (e) After the liquid adhesive is cured to form an encapsulation body, the substrate and the encapsulant body are taken out from the glue injection space to form a first package body, wherein the second part of each of the metal pillars of the first package body an end protruding from the top surface of the encapsulant; and (f) Aligning a plurality of second solder balls of a second package with the second ends of the metal pillars and soldering, and forming a plurality of first solder balls on the substrate of the first package, wherein There is a first gap between the first package body and the second package body.

The advantage of the present invention lies in that the first chip and the metal pillars are directly disposed on the first substrate when the first package is formed, and the first chip and the metal pillars are disposed on the first substrate before the first encapsulant is formed. The plastic film with both ends inserted into the mold is taken out after the mold is injected with glue and the first sealant is formed, and the second ends of the metal posts naturally protrude from the top surface of the first sealant; therefore, the layered packaging structure of the present invention In the manufacturing method, the second solder balls of the second package body can be precisely aligned with the metal pillars protruding from the first package body, and cover the second ends of the metal pillars after soldering, not only increasing the The accuracy of the alignment of the first package body and the second package body also improves the stability of electrical connection, so as to improve the manufacturing yield of the stacked package structure.

The present invention is aimed at improving the package-on-package structure. The technical content of the present invention will be described in detail below with examples and drawings.

First, please refer to FIG. 1 , which is a first embodiment of the package-on-package structure 1 of the present invention, which includes a first package body 10 and a second package body 20 , wherein the second package body 20 is stacked on the first package body 10 . on the package body 10 .

The above-mentioned first package 10 includes a first substrate 11 , at least one first chip 12 , a plurality of metal pillars 13 and a first encapsulant 14 , wherein the at least one first chip 12 and the metal pillars 13 are disposed and electrically connected to the first substrate 11 , the first encapsulant 14 is formed on the first substrate 11 and covers the at least one first chip 12 and the metal pillars 13 ; in this embodiment, the first The package body 10 includes a first chip 12 flip-chip bonded to the first substrate 11 , but the bonding method of the first chip 12 is not limited thereto. The first substrate 11 includes a plurality of first connecting wire layers 111 , and a plurality of first solder balls 112 are formed on the bottom surface with a first pitch L1 , wherein the first connecting wire layers 111 are connected to the first chip 12 . , the metal pillars 13 and the first solder balls 112 are electrically connected. Each of the metal pillars 13 includes a first end 131 and a second end 132 opposite to the first end 131 , wherein the first ends 131 of the metal pillars 13 are disposed at a third distance L3 and are electrically connected to the first end 131 . On a substrate 11, the second end 132 protrudes from the top surface of the first sealing compound 14 by a height H2; preferably, the heights of the metal pillars 13 are the same, so the height of the second ends 132 is the same, And the metal pillars 13 are copper pillars, but not limited to this.

The above-mentioned second package 20 includes a second substrate 21 , at least one second chip 22 and a second encapsulant 23 , wherein the at least one second chip 22 is disposed and electrically connected to the second substrate 21 , the The second encapsulant 23 is formed on the second substrate 21 and covers the at least one second chip 22; in this embodiment, the second encapsulant 20 includes two sets of second chips 22 stacked on each other. The chips 22 are bonded to the second substrate 21 by wire bonding respectively, but the bonding method of the second chips 22 is not limited to this. The second substrate 21 includes a plurality of second connecting wire layers 211, and a plurality of protruding second pads 212 are formed on the bottom surface. The second pads 212 respectively form a second solder ball 213, wherein the The second connecting wire layers 211 are electrically connected to the second chips 22 and the second solder balls 213, and the second solder balls 213 are arranged with a second spacing L2; preferably, the first spacing L1 is greater than The second distance L2 and the third distance L3 match the second distance L2.

In this embodiment, as shown in FIG. 1 , after the second solder balls 213 of the second package body 20 are aligned with the metal pillars 13 corresponding to the first package body 10 , the second solder balls 213 of the second package body 20 are aligned The solder balls 213 are soldered and covered on the corresponding second ends 132 of the metal pillars 13 , so the bottom surface of the second substrate 21 of the second package 20 and the first encapsulant 14 of the first package 10 There is a first gap H1 on the top surface of the metal post 13 . Since the second pads 212 protrude from the second substrate 21 , the first gap H1 is larger than the second end 132 of the metal post 13 protruding from the first sealant 14 height H2.

It can be seen from the above description that a plurality of metal pillars protruding from the first encapsulant are formed on the first package body, which are aligned with the second solder balls of the second package body and then welded. The second end is covered by the second solder balls, so as to improve the bonding precision of the first package body and the second package body, and improve the manufacturing yield of the stacked package structure.

The above is a description of the structure of the package-on-package structure of the present invention, and the detailed manufacturing method for completing the package-on-package structure is further described below.

First, please refer to FIG. 2A to FIG. 2G , which are the first embodiment of the manufacturing method of the package-on-package structure of the present invention, which includes the following steps (a) to (f).

In step (a), referring to FIGS. 2A , 2B and 2C, a first substrate 11 is first prepared; in this embodiment, the first substrate 11 includes a plurality of first connecting wire layers 111 ; As shown in FIG. 2B , a plurality of metal pillars 13 are formed on the first substrate 11 ; in this embodiment, the metal pillars 13 include a first end 131 and a second end 132 opposite to the first end 131 , wherein The first end 131 is electrically connected to the first connecting wire layer 111 ; as shown in FIG. 2C , at least one first chip 12 is disposed on the first substrate 11 ; in this embodiment, flip chip bonding a first chip 12 is performed. A chip 12 is placed on the first substrate 11 , but the bonding method of the first chip 12 is not limited thereto.

In step (b), please refer to FIG. 2D , the first substrate 11 , the first chip 12 and the metal pillars 13 thereon are fixed in a first mold 30 , and then fixed in a second mold A jig 41 is disposed in the 40, and an adhesive film 42 is formed on the surface of the jig 41 facing the first mold 30, and the adhesive film 42 has a thickness H3; in this embodiment, the first mold 30 and the first mold 30 are formed. The second mold 40 is an injection molding mold, so the first mold 30 is located below the second mold 40 .

In step (c), as shown in FIG. 2D , the first mold 30 and the second mold 40 are covered to form a glue injection space 50 ; in this embodiment, the second ends 132 of the metal posts 13 Penetrate the adhesive film 42 and press against the surface of the jig 41 .

In step (d), as shown in FIG. 2E , a liquid glue material 51 is filled in the glue injection space 50 to cover the first chip 12 and some of the metal pillars 13 .

In step (e), as shown in FIGS. 2E and 2F , after the liquid adhesive 51 is cured, a first encapsulant 14 is formed, and the first substrate 11 and the first encapsulant 14 are injected from the adhesive. The space 50 is taken out to form a first package body 10 ; in this embodiment, since the second end 132 of the metal post 13 penetrates the adhesive film 42 during glue injection, it is taken out from the glue injection space 50 and torn off After the adhesive film 42 protrudes out of the first sealing compound 14 ; after the first packaging body 10 is taken out from the adhesive injection space 50 and the adhesive film 42 is torn off, the top surface of the first sealing compound 14 will remain with the adhesive film 42 . The adhesive film 42 can be further removed by laser or ultraviolet light (not shown in the figure).

In step (f), as shown in FIG. 2G , a plurality of second solder balls 212 on the bottom surface of a pre-fabricated second package body 20 are respectively aligned with the protruding top surfaces of the first sealing compound 14 . The second ends 132 of the metal pillars 13 are soldered, and then a plurality of first solder balls 112 are formed on the bottom surface of the first substrate 11 of the first package body 10 to form the package stack structure 1 as shown in FIG. 1 ; In this embodiment, the second package body 20 includes a package structure in which two second chips 22 are bonded to a second substrate 21 by wire bonding, but the second package body 20 is not limited to this; The second end 132 of the 13 protrudes from the first sealing compound 14 with a height H2, so after the second solder balls 212 are respectively welded and covered with the corresponding second end 132 of the metal post 13, the There is a first gap H1 between a package body 10 and the second package body 20 , wherein the first gap H1 is greater than the height H2 of the second end 132 protruding from the first sealing protrusion 14 .

In the second embodiment of the present invention, it is substantially the same as the method of the first embodiment of the present invention, including steps (a) to (f), but steps (b), (c) and (d) are The first encapsulant 14 is formed by a compression molding die; as shown in FIG. 3A , in step (b), the first substrate 11 , the first chip 12 and the metal pillars 13 thereon are fixed on the first substrate 11 . In the first mold 30, the fixture 41 is disposed in the second mold 40, and the adhesive film 42 is formed on the surface of the fixture 41 facing the first mold 30, and the adhesive film 42 has a thickness H3; In this embodiment, the first mold 30 is located above the second mold 40 ; in step (c), as shown in FIG. 3B , the first mold 30 and the second mold 40 are covered to form an injection molding space 50, and the second ends 132 of the metal posts 13 penetrate the adhesive film 42 and abut against the surface of the fixture 41; in step (d), the glue injection space 50 is filled with the liquid glue material 51 to cover the first chip 12 and some of the metal pillars 13; in step (e), after the liquid adhesive material 51 is cured to form the first encapsulant 14, the first substrate 11 and The first sealing body 14 is taken out from the glue injection space 50 to obtain the first sealing body 10 as shown in FIG. 2F .

As can be seen from the above description, the stack packaging method of the present invention mainly disposes the first chip and the metal pillars on the first substrate directly when the first package is formed, and assembles the first chip before forming the first encapsulant. The second ends of the metal pillars are inserted into the adhesive film in the second mold, and after the first encapsulant body is formed by injection in the adhesive injection space, the second ends of the metal pillars naturally protrude from the first sealant. Therefore, the first sealing body of the present invention does not need additional laser perforation, and the metal posts of the present invention protruding from the first packaging body can be used for the second sealing body corresponding to the second packaging body. The solder balls are precisely aligned and then soldered to cover the protruding ends of the metal pillars, which not only eliminates the risk of perforation failure, but also increases the alignment accuracy and electrical connection stability of the first package body and the second package body. The overall production yield of the package-on-package structure; in addition, the jig can be compatible with existing injection molding molds or compression molding molds, and costs such as replacement of new sealing equipment are not required.

The above description is only an embodiment of the present invention, and is not intended to limit the present invention in any form. Although the present invention has been disclosed as above by embodiments, it is not intended to limit the present invention. Anyone with ordinary knowledge in the technical field, Within the scope of not departing from the technical solution of the present invention, when the technical content disclosed above can be used to make some changes or modifications to equivalent embodiments with equivalent changes, but any content that does not depart from the technical solution of the present invention, according to the technical essence of the present invention Any simple modifications, equivalent changes and modifications made to the above embodiments still fall within the scope of the technical solutions of the present invention.

1: Stacked package structure 10: The first package body 11: The first substrate 111: The first connecting line layer 112: The first solder ball 12: The first wafer 13: Metal Column 131: First End 132: Second End 14: The first sealant 20: Second package body 21: Second substrate 211: The second connecting line layer 212: Second pad 213: Second Solder Ball 22: Second wafer 23: The second sealant 30: The first mold 40: Second mold 41: Jig 42: Adhesive film 50: glue injection space 51: Liquid glue 60: Ball grid array package-on-package 61: Upper package body 611: First solder ball 62: Lower package body 621: Second Solder Ball 622: Pad 623: Sealant 624: Substrate 70: circuit board 80: Through-die perforated stack-on-package 81: Lower package body 811: Pad 812: Sealant 813: Wafer 82: Upper package body 821: Tin Ball

FIG. 1 is a cross-sectional view of an embodiment of the package-on-package structure of the present invention. 2A to 2G are cross-sectional views of different steps in the manufacturing method of the package-on-package structure of the present invention. 3A to 3B are cross-sectional views of different steps in another manufacturing method of the package-on-package structure of the present invention. FIG. 4 is a cross-sectional view of a prior art ball grid array package-on-package. FIG. 5: A cross-sectional view of a through-mold through-mold-on-package package in the prior art.

1: Stacked package structure

10: The first package body

11: The first substrate

111: The first connecting line layer

112: The first solder ball

12: The first wafer

13: Metal Column

131: First End

132: Second End

14: The first sealant

20: Second package body

21: Second substrate

211: The second connecting line layer

212: Second pad

213: Second Solder Ball

22: Second wafer

23: The second sealant

Claims (10)

A package-on-package structure comprising: A first package, comprising: a first substrate, the bottom surface of which forms a plurality of first solder balls with a first pitch; at least one first chip is disposed and electrically connected to the first substrate; a plurality of metal pillars, a first end of each of the metal pillars is disposed at a third interval and electrically connected to the first substrate; and A first encapsulant is formed on the first substrate and covers the at least one first chip and the metal pillars, wherein a second end of each of the metal pillars opposite to the first end is connected from the The top surface of the first colloid protrudes; and A second package, comprising: a second substrate, the bottom surface of which is formed with a plurality of second solder balls at a second interval, and each of the second solder balls is welded and covers the second end of the first package body corresponding to the metal column; wherein the The bottom surface of the second substrate and the top surface of the first encapsulant of the first package body have a first gap, and the second distance matches the third distance; at least one second chip disposed and electrically connected to the second substrate; and A second encapsulant is formed on the second substrate and covers the at least one second chip. The package-on-package structure as claimed in claim 1, wherein: and The second substrate of the second package further includes a second connecting wire layer, and the second connecting wire layer is electrically connected to the at least one second chip and each of the second solder balls. The package-on-package structure of claim 2, wherein the second ends of the metal pillars are of the same height. The package-on-package structure as claimed in claim 3, wherein a height at which the second end of each of the metal pillars protrudes from the first encapsulant is smaller than the first gap. The package-on-package structure of claim 4, wherein the spacing between the metal pillars matches the second spacing of the second solder balls. The package-on-package structure of claim 5, wherein the first pitch of the first solder balls is greater than the second pitch of the second solder balls. The package-on-package structure of claim 6, wherein the at least one first chip of the first package body is flip-chip bonded to the first substrate. A manufacturing method of a stacked package structure, comprising the following steps: (a) disposing at least one chip and a plurality of metal pillars on a substrate, wherein the first end of each of the metal pillars is disposed on the substrate; (b) fixing the substrate, the at least one chip and the metal pillars thereon in a first mold, and disposing a jig in a second mold, on the surface of the jig facing the first mold forming an adhesive film, the adhesive film has a thickness; (c) Covering the first mold and the second mold to form a glue injection space, wherein the second end of the metal posts opposite to the first end faces the fixture and penetrates through the plastic film and abuts against the jig. on the surface of the fixture; (d) filling the glue injection space with a liquid glue to cover the at least one chip and part of the metal pillars; (e) After the liquid adhesive is cured to form an encapsulation body, the substrate and the encapsulant body are taken out from the glue injection space to form a first package body, wherein the second part of each of the metal pillars of the first package body an end protruding from the top surface of the encapsulant; and (f) Aligning a plurality of second solder balls of a second package with the second ends of the metal pillars and soldering, and forming a plurality of first solder balls on the substrate of the first package, wherein There is a first gap between the first package body and the second package body. The method for manufacturing a package-on-package structure according to claim 8, wherein the first packaging system is formed by an injection molding process or a compression molding process. The method for manufacturing a package-on-package structure as claimed in claim 8 or 9, wherein in the step (e), the part of the adhesive film remaining on the top surface of the encapsulant after being taken out from the adhesive injection space is further removed by laser or UV light removal.

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