Dual-side plastic encapsulation method and encapsulation structure

Abstract

The embodiment of the present disclosure provides a packaging method and a packaging structure for double-sided plastic packaging. The method comprises the following steps: fixing a first chip on a first surface of a substrate; fixing a metal carrier plate on a side of the first chip away from the substrate, wherein an edge region of the metal carrier plate is provided with a plurality of conductive connection structures, and the metal carrier plate is fixedly connected with the substrate through the conductive connection structures; fixing a second chip on a second surface of the substrate; forming a plastic packaging layer on the first surface and the second surface of the substrate through a one-time plastic packaging process, and the plastic packaging layer wraps the second chip and the metal carrier plate respectively; and removing the metal carrier plate to expose the conductive connection structures and form a packaging body. The metal carrier plate and the plurality of conductive connection structures play a good bearing role on the substrate when the second chip is attached to the second surface of the substrate and when the substrate is cut after double-sided attachment. The one-time plastic packaging is used to form the plastic packaging layer, so as to reduce warping and increase yield.

Description

Technical Field

[0001] This disclosure pertains to the field of semiconductor packaging technology, specifically relating to a double-sided plastic encapsulation method and structure. Background Technology

[0002] Currently, in semiconductor packaging, double-sided molding typically involves two molding processes: first molding the front side of the substrate, then molding the back side. This sequential molding process leads to severe warping of the package structure. In existing single-stage double-sided molding processes, when mounting chips on both sides, the different heights of the chips on the front side create a lack of support during back-side mounting, making mounting difficult. Furthermore, the lack of support during back-side mounting and subsequent cutting after double-sided mounting makes cutting difficult and prone to chip damage.

[0003] To address the aforementioned issues, it is necessary to propose a well-designed and effective double-sided molding encapsulation method and structure. Summary of the Invention

[0004] The present disclosure aims to at least solve one of the technical problems existing in the prior art, and to provide a double-sided plastic encapsulation method and encapsulation structure.

[0005] One aspect of this disclosure provides a double-sided molding encapsulation method, wherein...

[0006] The methods include:

[0007] The first chip is fixed to the first surface of the substrate;

[0008] A metal carrier plate is fixed to the side of the first chip away from the substrate. The edge area of ​​the metal carrier plate is provided with multiple conductive connection structures, and the metal carrier plate is fixedly connected to the substrate through the conductive connection structures.

[0009] The second chip is fixed to the second surface of the substrate;

[0010] A molding process is used to form molding layers on the first and second surfaces of the substrate, respectively, and the molding layers encapsulate the second chip and the metal carrier plate.

[0011] Remove the metal carrier plate to expose the conductive connection structure, forming an encapsulation.

[0012] Optionally, fixing the metal carrier plate to the side of the first chip away from the substrate includes:

[0013] The metal carrier plate is fixed to the side of the first chip away from the substrate by hot pressing and reflowing process, and the plurality of conductive connection structures are fixed to the first surface of the substrate.

[0014] Optionally, fixing the first chip to the first surface of the substrate includes:

[0015] The first chip is flip-chip mounted on the first surface of the substrate;

[0016] An underfill layer is formed between the first chip and the first surface of the substrate.

[0017] Optionally, after fixing the first chip to the first surface of the substrate, the method further includes:

[0018] A solder metal layer is formed on the side of the first chip that is away from the substrate.

[0019] Optionally, removing the metal carrier plate to expose the conductive connection structure includes:

[0020] The metal support plate is removed by a grinding process to expose the conductive connection structure and the weld metal layer.

[0021] Optionally, after removing the metal carrier plate to expose the conductive connection structure and forming the package, the method further includes:

[0022] A shielding layer is formed around the plastic encapsulation layer, and the shielding layer covers the package.

[0023] Optionally, after removing the metal carrier plate to expose the conductive connection structure and forming the package, the method further includes:

[0024] A signal output layer is formed on the side of the conductive connection structure opposite to the substrate.

[0025] Optionally, the material of the metal support plate is copper.

[0026] Optionally, the conductive connection structure is a metal conductive pillar or a solder ball.

[0027] Another aspect of this disclosure provides a double-sided plastic encapsulation structure, which is formed by encapsulation using the encapsulation method described above.

[0028] The double-sided molding process and packaging structure disclosed herein include a method and structure for packaging a first chip fixed to the first surface of a substrate, and a metal carrier plate fixed to the first chip. When a second chip is mounted on the second surface of the substrate, the metal carrier plate and multiple conductive connection structures provide excellent support for the substrate, enabling successful chip mounting on the second surface. Furthermore, when the substrate is cut after double-sided mounting, the metal carrier plate and multiple conductive connection structures provide excellent support, reducing cutting difficulty and preventing chip damage. The packaging method of this disclosure uses a single molding process to form molding layers on both the first and second surfaces of the substrate, reducing warpage of the packaging structure and increasing its yield. Additionally, the metal carrier plate and multiple conductive connection structures ensure the stability of the substrate during the molding process, and the multiple conductive connection structures enhance the connection between the substrate and the metal carrier plate, preventing damage to the first and second chips from the impact of the molding compound, thus improving the yield of the molded product. Attached Figure Description

[0029] Figure 1 This is a schematic flowchart of a double-sided plastic encapsulation method according to one embodiment of the present disclosure;

[0030] Figures 2-8 This is a schematic diagram of a double-sided molding process according to another embodiment of this disclosure;

[0031] Figure 9 This is a schematic diagram of a double-sided plastic encapsulation structure according to another embodiment of the present disclosure. Detailed Implementation

[0032] To enable those skilled in the art to better understand the technical solutions of the embodiments of this disclosure, the embodiments of this disclosure will be further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0033] like Figure 1 As shown, one aspect of this disclosure provides a double-sided molding encapsulation method S100, the method S100 including:

[0034] S110. Fix the first chip to the first surface of the substrate.

[0035] like Figure 2 and Figure 3 As shown, the first chip 120 is fixed to the first surface of the substrate 110.

[0036] It should be understood that the first surface of the substrate 110 can be either the front or the back surface of the substrate 110, and can be selected according to actual needs. In this embodiment, the first surface of the substrate 110 is used as the back surface of the substrate 110, and the second surface of the substrate 110 is used as the front surface of the substrate 110 for illustrative purposes. That is, the first chip 120 is fixed to the back surface of the substrate 110.

[0037] It should be noted that this embodiment does not specifically limit the number and type of the first chip 120, which can be selected according to actual needs.

[0038] In this embodiment, fixing the first chip 120 to the first surface of the substrate 110 specifically includes:

[0039] like Figure 3 As shown, firstly, the first chip 120 is flip-chip mounted onto the first surface of the substrate 110. Specifically, the first chip 120 is flip-chip mounted onto the back side of the substrate 110 via conductive bumps 121.

[0040] It should be noted that there is no specific limitation on the method by which the first chip 120 is fixed to the back of the substrate 110. In addition to the flip-chip method in this embodiment, upright mounting and other methods can also be used, and the choice can be made according to actual needs.

[0041] Next, an underfill layer 122 is formed between the first chip 120 and the first surface of the substrate 110. The underfill layer 122 can better fix the first chip 120 to the back side of the substrate 110.

[0042] For example, after fixing the first chip to the first surface of the substrate, the method further includes:

[0043] like Figure 4 As shown, a solder metal layer 123 is formed on the side of the first chip 120 facing away from the substrate 110. In this embodiment, the solder metal layer 123 is made of a thermal interface material; preferably, it is made of indium. The solder metal layer 123 can prepare the first chip 120 for subsequent reflow soldering.

[0044] S120. Fix a metal carrier plate to the side of the first chip away from the substrate, wherein the edge area of ​​the metal carrier plate is provided with multiple conductive connection structures, and the metal carrier plate is fixedly connected to the substrate through the conductive connection structures.

[0045] like Figure 4As shown, a metal carrier plate 130 is fixed to the side of the first chip 120 facing away from the substrate 110. Multiple conductive connection structures 140 are pre-formed on the edge region of the metal carrier plate 130. The metal carrier plate 130 is fixedly connected to the substrate 110 through the conductive connection structures 140.

[0046] For example, fixing the metal carrier plate to the side of the first chip away from the substrate specifically includes:

[0047] Through a hot-press reflow process, a metal carrier plate 130 is fixed to the side of the first chip 120 facing away from the substrate 110 by welding a metal layer 123, and multiple conductive connection structures 140 are fixed to the back side of the substrate 110 by conductive bumps 121. The multiple conductive connection structures 140 serve both as supports and as electrical connections between the metal carrier plate 130 and the substrate 110.

[0048] It should be noted that in this embodiment, the metal bearing plate 130 is made of copper, but other metal materials can also be used. This embodiment does not make any specific limitations.

[0049] It should be further noted that the conductive connection structure 140 can be made of copper pillars or solder balls; preferably, the conductive connection structure 140 can be made of copper pillars or solder balls. For example... Figure 4 As shown, in this embodiment, the conductive connection structure 140 uses solder balls, that is, the metal carrier plate 130 is fixedly connected to the substrate 110 through multiple solder balls.

[0050] In the above embodiments, the metal carrier plate 130 and the conductive connection structure 140 can provide excellent support for the substrate 110 when the chip is mounted on the second surface of the substrate 110. In addition, when the substrate 110 is cut after double-sided mounting, the metal carrier plate 130 and the multiple conductive connection structures 140 provide excellent support for the substrate 110, which reduces the difficulty of cutting and does not damage the chip.

[0051] S130, Fix the second chip to the second surface of the substrate.

[0052] like Figure 5 As shown, the second chip 150 is fixed to the second surface of the substrate 110, that is, the second chip 150 is fixed to the front side of the substrate 110, thus completing the double-sided chip mounting of the substrate 110.

[0053] Specifically, such as Figure 5 As shown, after fixing the metal carrier plate 130 to the first chip 120, the metal carrier plate 130 is flipped over, with the metal carrier plate 130 serving as a support at the bottom, and then multiple second chips 150 are fixed to the front side of the substrate 110.

[0054] In this embodiment, the height of the multiple second chips 150 is not specifically limited; the heights of the multiple second chips 150 can be the same or different, and this embodiment does not impose a specific limitation. Furthermore, the number of second chips 150 is not specifically limited in this embodiment and can be selected according to actual needs.

[0055] In the above embodiments, the metal carrier plate 130 and the conductive connection structure 140 can provide good support for the substrate 110 when the second chip 150 is mounted on the second surface of the substrate 110, without being affected by the height of the second chip 150.

[0056] S140. Through a single molding process, molding layers are formed on the first and second surfaces of the substrate, respectively, and the molding layers encapsulate the second chip and the metal carrier plate.

[0057] Specifically, such as Figure 6 As shown, after mounting the substrate 110 on both sides, a molding process is performed to form molding layers 160 on the first and second surfaces of the substrate 110, respectively. The molding layers 160 encapsulate the second chip 150 and the metal carrier plate 130.

[0058] Specifically, the structure to be molded after the chip is mounted is placed into the molding die, that is, the metal carrier plate 130 is placed in the molding die as the bottom, molding material is injected, and through a single molding process, molding layers 160 are formed on the back and front sides of the substrate 110, respectively. The molding layers 160 encapsulate the second chip 150 and the metal carrier plate 130. The molding layers 160 protect the substrate 110, the first chip 120, the second chip 150, the metal carrier plate 130, and the multiple conductive connection structures 140.

[0059] After molding the structure to be molded to form a molding layer 160, the entire substrate 110 is cut to form an independent encapsulation structure.

[0060] In the above embodiments, the metal carrier plate 130 and the conductive connection structure 140 can play a good supporting role for the substrate 110 during the double-sided mounting and cutting process after molding, which can reduce the cutting difficulty and prevent damage to the chip.

[0061] In the above embodiments, a single molding process is used to form molding layers 160 on the first and second surfaces of the substrate 110, which can reduce the warpage of the packaging structure and increase the yield of the packaging structure. In addition, during the molding process, the substrate 110 needs to withstand the impact of the molding compound. The metal carrier plate 130 and multiple conductive connection structures 140 support the substrate 110, ensuring the stability of the substrate 110 during the molding process. At the same time, the multiple conductive connection structures 140 strengthen the connection between the metal carrier plate 130 and the substrate 110, thereby preventing the first chip 120 and the second chip 150 from being damaged by the impact of the molding compound, and improving the yield of the molded product.

[0062] S150. Remove the metal carrier plate to expose the conductive connection structure and form an encapsulation.

[0063] Specifically, such as Figure 7 As shown, the metal support plate 130 is ground using a grinding process to remove the metal support plate 130, so as to expose the conductive connection structure 140 and the welding metal layer 123 respectively.

[0064] For example, after removing the metal carrier plate to expose the conductive connection structure and forming the package, the method further includes:

[0065] like Figure 8 As shown, a shielding layer 170 is formed around the molding compound 160. The shielding layer 170 covers the package, leaving only one side exposed to allow signal output, which exposes the conductive connection structure 140 and the solder metal layer 123. The shielding layer 170 can prevent the entire package structure from being subjected to electromagnetic interference.

[0066] Because the bottom edge of the package is a molding layer 160, which means that the bottom edge of the package is a molding material and not a metal material, a shielding layer 170 is formed around the molding layer 160. The contact between the shielding layer 170 and the bottom edge of the package, which is the molding layer 160, will not cause a short circuit.

[0067] The specific steps for forming the shielding layer 170 around the package can be as follows:

[0068] A through-groove is formed around the entire periphery of the molding compound 160 using a molding compound perforation process. A metal layer is deposited in the through-groove using processes such as sputtering, thereby forming a shielding layer 170 around the periphery of the molding compound 160. In other words, a shielding layer 170 is formed around the entire periphery of the package, with only one side exposed to expose the conductive connection structure 140 and the solder metal layer 123 for signal output.

[0069] For example, after removing the metal carrier plate to expose the conductive connection structure and forming the package, the method further includes:

[0070] A signal output layer (not shown) is formed on the side of the conductive connection structure 140 opposite to the substrate 110.

[0071] like Figure 8 As shown, in this embodiment, the conductive connection structure 140 uses solder balls. Therefore, additional solder balls can be added to the exposed solder ball locations to bring out the signal from the package structure. Alternatively, additional solder can be added to the exposed solder ball locations to bring out the signal from the package structure. This embodiment does not specifically limit the specific structure of the signal output layer; it can be selected according to the actual situation.

[0072] In this embodiment, after a signal output layer is formed on the side of the conductive connection structure 140 away from the substrate 110, the entire package structure can be mounted on a square flat leadless package or on a PCB circuit board, and the signal of the package structure can be led out through the signal output layer.

[0073] like Figure 9 As shown, another aspect of this disclosure provides a double-sided plastic-encapsulated packaging structure 100, which is formed using the packaging method S100 described above. The specific steps of the packaging method S100 have been described in detail above and will not be repeated here.

[0074] like Figure 9 As shown, the double-sided plastic encapsulation structure 100 includes a substrate 110, a first chip 120 disposed on a first surface of the substrate 110, a second chip 150 disposed on a second surface of the substrate 110, and a plastic encapsulation layer 160, wherein a plurality of conductive connection structures 140 are disposed on the edge region of the first surface of the substrate 110.

[0075] like Figure 9 As shown, a molding compound 160 is disposed on the first and second surfaces of the substrate 110, and the molding compound 160 encapsulates the substrate 110, the first chip 120, the second chip 150, and a plurality of conductive connection structures 140. The molding compound 160 protects the substrate 110, the first chip 120, the second chip 150, and the plurality of conductive connection structures 140.

[0076] Specifically, a molding process is used to form molding layers 160 on the first and second surfaces of the substrate 110, which reduces the warpage of the packaging structure 100 and increases the yield of the packaging structure 100.

[0077] It should be noted that the conductive connection structure 140 can be made of copper pillars or solder balls. Preferably, the conductive connection structure 140 can be made of copper pillars or solder balls. In this embodiment, the conductive connection structure 140 uses solder balls.

[0078] It should be understood that the first surface of the substrate 110 can be either the front or the back surface of the substrate 110, and can be selected according to actual needs. In this embodiment, the first surface of the substrate 110 is used as the back surface of the substrate 110, and the second surface of the substrate 110 is used as the front surface of the substrate 110 for illustrative purposes. That is, the first chip 120 is fixed to the back surface of the substrate 110.

[0079] For example, such as Figure 9 As shown, the packaging structure 100 further includes a solder metal layer 123, which is disposed on the side of the first chip 120 facing away from the substrate 110. In this embodiment, the solder metal layer 123 is made of a thermal interface material, preferably, it is made of indium.

[0080] For example, such as Figure 9 As shown, in this embodiment, the first chip 120 is flip-chip mounted on the back side of the substrate 110 via conductive bumps 121. An underfill layer 122 is provided between the first chip 120 and the substrate 110. The underfill layer 122 can better fix the first chip 120 to the back side of the substrate 110.

[0081] like Figure 9 As shown, the encapsulation structure 100 also includes a shielding layer 170, which surrounds the molding compound 160. The shielding layer 170 is a metal layer and can prevent the entire encapsulation structure from being subjected to electromagnetic interference.

[0082] The double-sided molding encapsulation structure of this disclosure uses a single molding process to form molding layers on the first and second surfaces of the substrate, reducing warpage and increasing the yield of the encapsulation structure. The conductive connection structure can support the substrate during the molding process, ensuring the stability of the substrate during molding. This can prevent the first and second chips from being damaged by the impact of the molding material, thus improving the yield of the molded product.

[0083] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the embodiments of this disclosure, and the embodiments of this disclosure are not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the embodiments of this disclosure, and these modifications and improvements are also considered to be within the protection scope of the embodiments of this disclosure.

Claims

1. A double-sided plastic encapsulation method, characterized in that, The method includes: The first chip is fixed to the first surface of the substrate; A metal carrier plate is fixed to the side of the first chip away from the substrate. The edge area of ​​the metal carrier plate is provided with multiple conductive connection structures, and the metal carrier plate is fixedly connected to the substrate through the conductive connection structures. The second chip is fixed to the second surface of the substrate; wherein, when the second chip is mounted on the second surface of the substrate and when the substrate is cut after double-sided mounting, the metal carrier plate and the plurality of conductive connection structures support the substrate. A molding process is used to form molding layers on the first and second surfaces of the substrate, respectively, and the molding layers encapsulate the second chip and the metal carrier plate. Remove the metal carrier plate to expose the conductive connection structure, forming an encapsulation.

2. The method according to claim 1, characterized in that, The step of fixing the metal carrier plate to the side of the first chip away from the substrate includes: The metal carrier plate is fixed to the side of the first chip away from the substrate by hot pressing and reflowing process, and the plurality of conductive connection structures are fixed to the first surface of the substrate.

3. The method according to claim 1, characterized in that, The step of fixing the first chip to the first surface of the substrate includes: The first chip is flip-chip mounted on the first surface of the substrate; An underfill layer is formed between the first chip and the first surface of the substrate.

4. The method according to any one of claims 1 to 3, characterized in that, After fixing the first chip to the first surface of the substrate, the method further includes: A solder metal layer is formed on the side of the first chip that is away from the substrate.

5. The method according to claim 4, characterized in that, Removing the metal support plate to expose the conductive connection structure includes: The metal support plate is removed by a grinding process to expose the conductive connection structure and the weld metal layer.

6. The method according to any one of claims 1 to 3, characterized in that, After removing the metal carrier plate to expose the conductive connection structure and forming the package, the method further includes: A shielding layer is formed around the plastic encapsulation layer, and the shielding layer covers the package.

7. The method according to any one of claims 1 to 3, characterized in that, After removing the metal carrier plate to expose the conductive connection structure and forming the package, the method further includes: A signal output layer is formed on the side of the conductive connection structure opposite to the substrate.

8. The method according to any one of claims 1 to 3, characterized in that, The material of the metal support plate is copper.

9. The method according to any one of claims 1 to 3, characterized in that, The conductive connection structure is a metal conductive pillar or a solder ball.

10. A double-sided plastic-encapsulated packaging structure, formed by packaging using the packaging method described in any one of claims 1 to 9.

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