Dual-sided plastic encapsulated system in package method and structure

Abstract

The embodiment of the present disclosure provides a double-sided plastic packaging system-level packaging method and packaging structure, the method comprises the following steps: providing a substrate, a first chip, a second chip and a metal support plate, the edge region of the metal support plate is provided with a plurality of conductive supports; fixing the first chip on the first surface of the substrate; fixing the metal support plate on the first chip, and the metal support plate is electrically connected with the substrate through the conductive supports; fixing the second chip on the second surface of the substrate; forming a plastic package on the first surface and the second surface of the substrate respectively through a one-time plastic packaging process, and the plastic package wraps the second chip and the metal support plate; patterning the metal support plate to form a preset pattern on the metal support plate. The metal support plate and the conductive support 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 the double-sided attachment is completed; the one-time plastic packaging is used to form the plastic package, the warping is reduced, and the yield is increased.

Description

Technical Field

[0001] This disclosure pertains to the field of semiconductor packaging technology, specifically relating to a double-sided plastic encapsulation system-level packaging method and packaging 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 leads to severe warping of the package structure. Furthermore, mounting a strip-shaped adapter / molding layer on the back side of the substrate results in poor overall heat dissipation. In existing single-stage double-sided molding processes, the difference in chip height on the front side creates a lack of support during back-side mounting, making it difficult. The lack of support during back-side mounting and subsequent cutting after double-sided mounting further complicates the process and easily damages the chips.

[0003] To address the aforementioned issues, it is necessary to propose a well-designed and effective double-sided plastic encapsulation system-level packaging 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 system-level packaging method and packaging structure for double-sided plastic encapsulation.

[0005] One aspect of this disclosure provides a system-level packaging method for double-sided molding, the method comprising:

[0006] A substrate, a first chip, a second chip, and a metal support plate are provided, wherein multiple conductive support members are provided on the edge region of the metal support plate;

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

[0008] The metal support plate is fixed to the first chip, wherein the metal support plate is electrically connected to the substrate through a plurality of conductive support members;

[0009] A molding process is used to form molding bodies on the first and second surfaces of the substrate, respectively, and the molding bodies encapsulate the second chip and the metal support plate.

[0010] The metal support plate is graphically represented, and a preset pattern is formed on the metal support plate.

[0011] Optionally, after fixing the metal support plate to the first chip, the method further includes:

[0012] According to the preset pattern, a metal plating layer is formed on the side of the metal support plate opposite to the first chip.

[0013] Optionally, after fixing the first chip to the first surface of the substrate, the method further includes:

[0014] A solder metal layer is formed on the side of the first chip that is away from the substrate.

[0015] Optionally, fixing the first chip to the first surface of the substrate includes:

[0016] The first chip is flip-chip mounted on the first surface of the substrate;

[0017] An underfill layer is formed between the first chip and the first surface of the substrate.

[0018] Optionally, fixing the metal support plate to the first chip, wherein the first chip is electrically connected to the substrate through a plurality of conductive supports, includes:

[0019] The metal support plate is fixed to the first chip and the plurality of conductive support members are fixed to the first surface of the substrate by means of a hot-press reflow process.

[0020] Optionally, after the metal support plate is graphically formed with a preset pattern, the method further includes:

[0021] If the edge region of the patterned metal support plate is the metal support plate, then a shielding layer is formed around the second chip.

[0022] Optionally, after the metal support plate is graphically formed with a preset pattern, the method further includes:

[0023] If the edge area of ​​the graphically rendered metal support plate is the molding compound, then a shielding layer is formed around the molding compound.

[0024] Optionally, after the metal support plate is graphically formed with a preset pattern, the method further includes:

[0025] A signal output layer is formed on the side of the metal support plate opposite to the substrate.

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

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

[0028] The present disclosure discloses a system-level packaging method and packaging structure for double-sided molding. In the packaging method, a first chip is fixed to the first surface of a substrate, and then a metal support plate is fixed to the first chip. In this way, when a second chip is mounted on the second surface of the substrate, the metal support plate and multiple conductive support members play a good supporting role for the substrate, which can effectively realize the chip mounting on the second surface of the substrate.

[0029] In addition, when cutting the substrate after double-sided mounting, the metal support plate and multiple conductive support components provide excellent support for the substrate, which reduces the difficulty of cutting and does not damage the chip.

[0030] The packaging method of this disclosure uses a single molding process to form a molding compound on the first and second surfaces of the substrate, thereby reducing the warpage of the packaging structure and increasing the yield of the packaging structure.

[0031] In addition, during the molding process, the metal support plate and multiple conductive support components support the substrate, ensuring the stability of the substrate during the molding process. The multiple conductive support structures strengthen the connection between the substrate and the metal support plate, thereby preventing the first chip 120 and the second chip from being damaged by the molding material, and improving the yield of the molded product.

[0032] The packaging method of this embodiment fixes the metal support plate to the first chip and can also dissipate heat from the first chip. Attached Figure Description

[0033] Figure 1 This is a schematic flowchart of a system-level encapsulation method for double-sided molding as described in one embodiment of this disclosure;

[0034] Figures 2-9 This is a schematic diagram of the packaging process for a double-sided plastic encapsulation system-level packaging method according to another embodiment of this disclosure;

[0035] Figure 10 This is a schematic diagram of a double-sided plastic-encapsulated system-in-package structure according to another embodiment of the present disclosure;

[0036] Figure 11 This is a schematic diagram of a double-sided plastic encapsulation system-in-package structure according to another embodiment of this disclosure. Detailed Implementation

[0037] 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.

[0038] like Figure 1As shown, one aspect of this disclosure provides a system-in-package (SI) method S100 with double-sided molding compound, the method S100 including:

[0039] S110. A substrate, a first chip, a second chip, and a metal support plate are provided, wherein a plurality of conductive support members are provided on the edge region of the metal support plate.

[0040] Specifically, such as Figures 2 to 5 As shown, a substrate 110, a first chip 120, a second chip 130, and a metal support plate 140 are provided. Multiple conductive support members 150 are pre-formed on the edge region of the metal support plate 140. These conductive support members 150 serve both a supporting function and an electrical connection function.

[0041] It should be noted that in this embodiment, the metal support plate 140 is made of copper, but other metal materials can also be used. This embodiment does not make any specific limitations.

[0042] It should be further noted that the conductive support 150 can be made of copper pillars or solder balls; preferably, the conductive support 150 can be made of copper pillars or solder balls. Figure 4 As shown, in this embodiment, the conductive support 150 is made of copper pillar.

[0043] S120. Fix the first chip to the first surface of the substrate.

[0044] Specifically, such as Figure 3 The first chip 120 is fixed to the first surface of the substrate 110.

[0045] 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.

[0046] In this embodiment, fixing the first chip 120 to the first surface of the substrate 110 specifically includes:

[0047] 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.

[0048] 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.

[0049] It should be noted that this embodiment does not specifically limit the number of the first chip 120, which can be one, two or more, and can be selected according to actual needs.

[0050] 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.

[0051] For example, after fixing the first chip to the first surface of the substrate, the method further includes:

[0052] 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.

[0053] S130. Fix the metal support plate to the first chip, wherein the metal support plate is electrically connected to the substrate through a plurality of conductive support members.

[0054] like Figure 4 As shown, a metal support plate 140 is fixed to the first chip 120, wherein the metal support plate 140 is electrically connected to the substrate 110 through multiple conductive support members 150. Fixing the metal support plate 140 to the first chip 120 can serve to dissipate heat from the first chip 120.

[0055] Specifically, such as Figure 4 As shown, the metal support plate 140 is fixed to the first chip 120 by welding the metal layer 123 through a hot-press reflow process, and multiple conductive support members 150 are fixed to the back of the substrate 110 by conductive bumps 121. The multiple conductive support members serve two purposes: firstly, to provide support, and secondly, to electrically connect the metal support plate 140 to the substrate.

[0056] For example, after fixing the metal support plate to the first chip, the method further includes:

[0057] like Figure 6 As shown, according to the preset pattern, a metal plating layer 160 is formed on the side of the metal support plate 140 opposite to the first chip 120.

[0058] Specifically, a photoresist layer is formed on the side of the metal support plate 140 opposite to the first chip 120. A mask with a preset pattern is placed on the photoresist layer. Using the mask as a template, the photoresist layer is exposed and developed to transfer the preset pattern from the mask onto the photoresist layer. A metal plating layer 160 is deposited on the preset pattern on the photoresist layer using electroplating or sputtering processes.

[0059] It should be noted that in this embodiment, the metal plating layer 160 is an electroplated gold layer. Of course, the material of the metal plating layer 160 can also be other metal materials, and this embodiment does not make specific limitations.

[0060] In the above embodiments, a metal plating layer 160 is formed on the side of the metal support plate 140 away from the first chip 120, which can prevent the metal support plate 140 from being etched and play a role in protecting the metal support plate 140.

[0061] S140. Fix the second chip to the second surface of the substrate.

[0062] like Figure 5 As shown, after fixing the metal support plate 140 to the first chip 120, the metal support plate 140 is flipped over, and the second chip 130 is fixed to the front side of the substrate 110, completing the double-sided chip mounting of the substrate 110. That is, as... Figure 5 As shown, a metal support plate 140 serves as a support at the bottom, and then multiple second chips 130 are fixed to the front side of the substrate 110. In this embodiment, the height of the multiple second chips 130 is not specifically limited; the heights of the multiple second chips 130 can be the same or different, and this embodiment does not impose a specific limitation. In addition, the number of second chips 130 is not specifically limited in this embodiment and can be selected according to actual needs.

[0063] S150. Through a single molding process, a molding compound is formed on the first and second surfaces of the substrate, respectively, and the molding compound encapsulates the second chip and the metal support plate.

[0064] Specifically, such as Figure 6 As shown, after mounting the substrate 110 on both sides, a molding process is performed to form a molding compound 170 on the first and second surfaces of the substrate 110, respectively. The molding compound 170 encapsulates the second chip 130 and the metal support plate 140.

[0065] Specifically, the chip-mounted substrate is placed into a molding die, with the metal support plate 140 placed as the bottom. Molding material is injected, and through a single molding process, a molding compound 170 is formed on both the back and front sides of the substrate 110. The molding compound 170 encapsulates the second chip 130 and the metal support plate 140. The molding compound 170 protects the substrate 110, the first chip 120, the second chip 130, the metal support plate 140, and the multiple conductive supports 150.

[0066] Of these, only the side of the metal support plate 140 facing the substrate 110 has a molding compound 170 formed, while the side of the metal support plate 140 away from the substrate 110 does not have a molding compound 170 formed.

[0067] After molding the structure to be molded to form a molded body 170, the entire substrate 110 is cut to form an independent encapsulation structure.

[0068] In the above embodiments, the metal support plate 140 and the multiple conductive support members 150 can play a good supporting role for the substrate 110 during the cutting process after the substrate 110 is double-sided mounted and encapsulated, which can reduce the cutting difficulty and prevent damage to the chip.

[0069] In the above embodiments, a single molding process is used to form the molding compound 170 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 support plate 140 and multiple conductive support members 150 play a supporting role for the substrate 110, ensuring the stability of the substrate 110 during the molding process. Among them, the multiple conductive support structures 150 strengthen the connection between the substrate 110 and the metal support plate 140, thereby avoiding damage to the first chip 120 and the second chip 130 caused by the impact of the molding compound, and improving the yield of the molded product.

[0070] S160. Graphicalize the metal support plate and form a preset pattern on the metal support plate.

[0071] Specifically, such as Figure 7 As shown, a chemical etching process is used to pattern the metal support plate 140, forming a preset pattern on the metal support plate 140. The metal plating layer 160 formed on the metal support plate 140 can prevent the non-patterned parts of the metal support plate 140 from being chemically etched during the chemical etching process.

[0072] It should be noted that the process for patterning the metal support plate 140 is not specifically limited in this embodiment, and can be selected according to actual needs, and is not limited to the chemical etching process in this embodiment.

[0073] For example, after the metal support plate is graphically formed with a preset pattern, the method further includes:

[0074] like Figure 8 As shown, if the edge region of the patterned metal support plate 140 is the metal support plate 140, then a shielding layer 180 is formed around each second chip 130. The shielding layer 180 can prevent the second chip 130 from being subjected to electromagnetic interference.

[0075] Because the bottom edge of the package structure is a metal support plate 140, that is, the bottom edge of the package structure is a metal layer, if a shielding layer 180 is formed around the entire package structure, the contact between the shielding layer 180 and the metal layer at the bottom edge of the package structure will cause a short circuit. Therefore, a shielding layer 180 is formed around each second chip 130.

[0076] The steps for forming the shielding layer 180 in a system-in-package structure can be as follows:

[0077] A through-groove is formed on the plastic encapsulation body 170 surrounding the second chip 130 using a plastic encapsulation material perforation process. A metal layer is deposited in the through-groove using processes such as sputtering, thereby forming a shielding layer 180 surrounding the second chip 130.

[0078] For example, after the metal support plate is graphically formed with a preset pattern, the method further includes:

[0079] like Figure 9 As shown, if the edge region of the patterned metal support plate 140 is a molding compound 170, a shielding layer 180 is formed around the molding compound 170, leaving only one side with the patterned metal support plate 140 exposed for signal output. The shielding layer 180 can prevent the entire system-on-a-package structure from being subjected to electromagnetic interference.

[0080] Because the bottom edge of the package structure is a molding compound 170, which means that the bottom edge of the package structure is a molding compound and not a metal material, a shielding layer 180 is formed around the molding compound 170. The contact between the shielding layer 180 and the bottom edge of the package structure is the molding compound 170 will not cause a short circuit.

[0081] The specific steps for forming a shielding layer 180 around the system-in-package structure can be as follows:

[0082] A through-groove is formed around the molded body 170 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 180 around the molded body 170. In other words, a shielding layer 180 is formed around the entire package structure, leaving only one side with the patterned metal support plate 140 exposed for signal output.

[0083] For example, after the metal support plate is graphically formed with a preset pattern, the method further includes:

[0084] A signal output layer (not shown) is formed on the metal support plate 140 to bring out the signals of the system-in-package structure. Specifically, in this embodiment, the signal output layer is formed on the metal plating layer 160. In this embodiment, a tin layer may be applied to the metal plating layer 160 to bring out the signals of the system-in-package structure. The specific structure of the signal output layer is not specifically limited in this embodiment and can be selected according to the actual situation. For example, the signal output layer may be solder balls, etc.

[0085] In this embodiment, after the signal output layer is formed on the metal support plate 140, the entire system-in-package structure can be mounted on a square flat leadless package or on a PCB circuit board, and the signals of the system-in-package structure can be led out through the signal output layer.

[0086] like Figure 10 and Figure 11 As shown, another aspect of this disclosure provides a double-sided molded system-in-package structure 100, which is formed by encapsulation using the encapsulation method S100 described above. The specific steps of the encapsulation method S100 have been described in detail above and will not be repeated here.

[0087] like Figure 10 and Figure 11 As shown, the double-sided plastic-encapsulated system-in-package (SIIP) structure 100 includes a substrate 110, a first chip 120 disposed on a first surface of the substrate 110, a second chip 130 disposed on a second surface of the substrate 110, and a metal support plate 140 disposed on the side of the first chip 120 facing away from the substrate 110. The edge region of the metal support plate 140 is provided with multiple conductive support members 150. These conductive support members 150 serve both a supporting function and an electrical connection function.

[0088] It should be noted that the metal support plate 140 is provided with a preset pattern, that is, the metal support plate 140 is graphically represented according to the preset pattern.

[0089] like Figure 10 and Figure 11As shown, a molding compound 170 is provided on the first and second surfaces of the substrate 110, and the molding compound 170 encapsulates the second chip 130 and the metal support plate 140. The molding compound 170 protects the substrate 110, the first chip 120, the second chip 130, the metal support plate 140, and the multiple conductive support members 150.

[0090] Specifically, a single molding process is used to form a molding compound 170 on the first and second surfaces of the substrate 110, which reduces the warpage of the encapsulation structure 100 and increases the yield of the encapsulation structure 100.

[0091] It should be noted that in this embodiment, the metal support plate 140 is made of copper, but other metal materials can also be used. This embodiment does not make any specific limitations.

[0092] It should be further noted that the conductive support 150 can be made of copper pillars or solder balls; preferably, the conductive support 150 can be made of copper pillars or solder balls. In this embodiment, the conductive support 150 is made of copper pillars.

[0093] 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.

[0094] For example, such as Figure 10 and Figure 11 As shown, the packaging structure 100 further includes a solder metal layer 123, which is sandwiched between the first chip 120 and the metal support plate 140. In this embodiment, the solder metal layer 123 is made of a thermal interface material; preferably, the solder metal layer 123 is made of indium.

[0095] For example, such as Figure 10 and Figure 11 As shown in this embodiment, the first chip 120 is flip-mounted onto the back side of the substrate 110 via conductive bumps 121. An underfill layer 122 is disposed 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.

[0096] For example, such as Figure 10 and Figure 11 As shown, the packaging structure 100 also includes a metal plating layer 160, which is disposed on the side of the metal support plate 140 facing away from the substrate 110. The metal plating layer 160 protects the metal support plate 140.

[0097] like Figure 10 and Figure 11 As shown, the encapsulation structure 100 also includes a shielding layer 180, such as... Figure 10 As shown, if the edge region of the metal support plate 140 is the metal support plate 140, then the shielding layer 180 surrounds the second chip 130. Figure 11 As shown, if the edge area of ​​the metal support plate 140 is a molding compound 170, then the shielding layer 180 is disposed around the entire encapsulation structure 100.

[0098] In the double-sided plastic-encapsulated system-in-package structure of this disclosure, the metal support plate and multiple conductive support members provide excellent support for the substrate when the second chip is mounted on the second surface of the substrate, enabling effective chip mounting on the second surface of the substrate. Furthermore, when the substrate is cut after double-sided mounting, the metal support plate and multiple conductive support members provide excellent support, reducing the difficulty of cutting and preventing damage to the chip. The single-stage plastic encapsulation process forms the encapsulation body on both the first and second surfaces of the substrate, reducing warpage of the package structure and increasing its yield. Placing the metal support plate on the first chip also helps dissipate heat from the first chip.

[0099] 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 system-level encapsulation method with double-sided molding, characterized in that, The method includes: A substrate, a first chip, a second chip, and a metal support plate are provided, wherein multiple conductive support members are provided on the edge region of the metal support plate; The first chip is fixed to the first surface of the substrate; The metal support plate is fixed to the first chip, wherein the metal support plate is electrically connected to the substrate through a plurality of conductive support members; 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 the substrate is cut after double-sided mounting, the metal support plate and the plurality of conductive support members support the substrate. A molding process is used to form molding bodies on the first and second surfaces of the substrate, respectively, and the molding bodies encapsulate the second chip and the metal support plate. The metal support plate is graphically represented, and a preset pattern is formed on the metal support plate.

2. The method according to claim 1, characterized in that, After fixing the metal support plate to the first chip, the method further includes: According to the preset pattern, a metal plating layer is formed on the side of the metal support plate opposite to the first chip.

3. The method according to claim 1, 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.

4. The method according to any one of claims 1 to 3, 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.

5. The method according to any one of claims 1 to 3, characterized in that, The step of fixing the metal support plate to the first chip, wherein the first chip is electrically connected to the substrate through a plurality of conductive support members, includes: The metal support plate is fixed to the first chip and the plurality of conductive support members are fixed to the first surface of the substrate by means of a hot-press reflow process.

6. The method according to any one of claims 1 to 3, characterized in that, After the metal support plate is graphically formed, and a preset pattern is created on the metal support plate, the method further includes: If the edge region of the patterned metal support plate is the metal support plate, then a shielding layer is formed around the second chip.

7. The method according to any one of claims 1 to 3, characterized in that, After the metal support plate is graphically formed, and a preset pattern is created on the metal support plate, the method further includes: If the edge area of ​​the graphically rendered metal support plate is the molding compound, then a shielding layer is formed around the molding compound.

8. The method according to any one of claims 1 to 3, characterized in that, After the metal support plate is graphically formed, and a preset pattern is created on the metal support plate, the method further includes: A signal output layer is formed on the side of the metal support plate opposite to the substrate.

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

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

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