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, which comprises the following steps: providing a substrate and fixing a plurality of first chips on the first surface of the substrate; providing a patterned metal frame, forming a plurality of second chips stacked in sequence in the central region of the metal frame, and forming a plurality of conductive support structures in the edge region of the metal frame; fixing the second surface of the substrate to the side of the second chip away from the metal frame and the metal frame respectively, and the substrate is electrically connected to the metal frame through the plurality of conductive support structures; forming a plastic package on the first surface and the second surface of the substrate by a one-time plastic packaging process. When the second chip is attached to the second surface of the substrate, the metal frame and the conductive support structure play a supporting role for the substrate, realizing the chip attachment on the second surface of the substrate; when the substrate is cut after the double-sided attachment is completed, the metal frame and the conductive support structure play a supporting role for the substrate, the cutting difficulty is reduced, and the chips will not be damaged.

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, the strip-shaped adapter plate / molding layer mounted 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 mounting difficult. 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 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 is provided, and a plurality of first chips are fixed to a first surface of the substrate;

[0007] A graphical metal frame is provided, in which a plurality of second chips are formed in sequence in the central region of the metal frame, and a plurality of conductive support structures are formed in the edge region of the metal frame.

[0008] The second surface of the substrate is fixed to the side of the second chip away from the metal frame and the metal frame, respectively, wherein the substrate is electrically connected to the metal frame through the plurality of conductive support structures;

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

[0010] Optionally, the formation of multiple conductive support structures in the edge region of the metal frame includes:

[0011] Multiple fixing plates are formed in the edge region of the metal frame;

[0012] A groove is formed on the fixing plate;

[0013] A corresponding conductive support structure is formed within the groove.

[0014] Optionally, fixing the second surface of the substrate to the side of the second chip facing away from the metal frame includes:

[0015] The second surface of the substrate is fixed to the side of the second chip away from the metal frame by conductive bumps.

[0016] Optionally, fixing the second surface of the substrate to the metal frame includes:

[0017] The conductive support structure is fixed to the second surface of the substrate by a hot-press reflow process, thereby fixing the second surface of the substrate to the metal frame.

[0018] Optionally, after forming the encapsulated body on the first and second surfaces of the substrate through a single encapsulation process, the method further includes:

[0019] If the edge region of the graphical metal frame is the metal frame, then a shielding layer is formed around the first chip.

[0020] Optionally, after forming the encapsulated body on the first and second surfaces of the substrate through a single encapsulation process, the method further includes:

[0021] If the edge region of the graphical metal frame is the encapsulated body, then a shielding layer is formed around the encapsulated body.

[0022] Optionally, after forming the encapsulated body on the first and second surfaces of the substrate through a single encapsulation process, the method further includes:

[0023] A signal output layer is formed on the side of the metal frame opposite to the substrate.

[0024] Optionally, the conductive support structure is a metal conductive pillar or a solder ball.

[0025] Optionally, the metal frame is made of copper.

[0026] 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.

[0027] The present disclosure discloses a system-level packaging method and packaging structure for double-sided molding. In the packaging method, multiple first chips are fixed to the first surface of a substrate, and multiple second chips are formed in the central region of a metal frame and stacked sequentially. Then, the second surface of the substrate is fixed to the side of the second chips away from the metal frame and the metal frame, respectively. The substrate is electrically connected to the metal frame through multiple conductive support structures. After the second chips are fixed to the metal frame, the second chips are then mounted on the second surface of the substrate. In this way, when multiple second chips are mounted on the second surface of the substrate, the metal frame and multiple conductive support structures provide good support for the substrate, and the chip mounting on the second surface of the substrate can be well realized.

[0028] In addition, when the substrate is cut after double-sided mounting, the metal frame and multiple conductive support structures provide excellent support for the substrate, which reduces the difficulty of cutting and does not damage the chip.

[0029] 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.

[0030] In addition, during the molding process, the metal frame and multiple conductive support structures support the substrate, ensuring its stability during molding. The multiple conductive support structures strengthen the connection between the substrate and the metal frame, thereby preventing the first and second chips from being damaged by the molding compound and improving the yield of the molded product.

[0031] The packaging method of this disclosure involves forming a plurality of second chips stacked sequentially in the central region of a metal frame, and the metal frame can dissipate heat from the plurality of second chips. Attached Figure Description

[0032] 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;

[0033] Figures 2-9 This is a schematic diagram of the packaging process for a double-sided plastic encapsulated system-in-package according to another embodiment of this disclosure;

[0034] 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;

[0035] 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

[0036] 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.

[0037] like Figure 1 As shown, one aspect of this disclosure provides a system-in-package (SI) method S100 with double-sided molding compound, the method S100 including:

[0038] S110. Provide a substrate and fix a plurality of first chips to a first surface of the substrate.

[0039] like Figures 1 to 3 As shown, a substrate 110 is provided, and a plurality of first chips 120 are fixed to the first surface of the substrate 110.

[0040] It should be noted that the height and size of the first chip 120 are not specifically limited in this embodiment, but can be limited according to actual needs.

[0041] 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 front surface of the substrate 110, and the second surface of the substrate 110 is used as the back surface of the substrate 110 for illustrative purposes. That is, a plurality of first chips 120 are fixed to the front surface of the substrate 110.

[0042] S120. A graphical metal frame is provided, in which a plurality of second chips are formed in sequence in the central region of the metal frame, and a plurality of conductive support structures are formed in the edge region of the metal frame.

[0043] like Figure 4 As shown, a graphical metal frame 130 is provided, with a plurality of second chips 140 stacked sequentially in the central region of the metal frame 130, and a plurality of conductive support structures 150 formed in the edge region of the metal frame 130. The number of second chips 140 is not specifically limited in this embodiment and can be selected according to actual needs.

[0044] It should be noted that the metal plate is pre-etched using an etching process to form a patterned metal frame 130. This embodiment does not specifically limit the shape of the patterned metal frame 130; it can be selected according to actual needs. For example, the metal frame 130 can be as follows: Figure 10 The shape shown can also be like... Figure 11 The shape shown.

[0045] It should be further noted that, in this embodiment, the metal frame 130 is preferably made of copper, but other metal materials may also be used; this embodiment does not impose any specific limitations.

[0046] It should be noted that the conductive support structure 150 can be made of copper pillars or solder balls; preferably, the conductive support structure 150 can be made of copper pillars or solder balls. Figure 4 As shown, in this embodiment, the conductive support structure 150 preferably uses solder balls.

[0047] For example, multiple conductive support structures are formed in the edge region of the metal frame, including:

[0048] like Figure 5 As shown, firstly, multiple fixing plates 131 are formed in the edge region of the metal frame 130.

[0049] A groove is formed on the fixing plate 131 (not shown in the figure).

[0050] A corresponding conductive support structure 150 is formed within the groove. In this embodiment, that is, a corresponding solder ball is formed within the groove.

[0051] In the above embodiments, a corresponding conductive support structure 150 is formed in the groove, which can better fix and position the conductive support structure 150, so that the conductive support structure 150 is more firmly fixed to the metal frame 130.

[0052] S130. The second surface of the substrate is fixed to the side of the second chip away from the metal frame and the metal frame, respectively, wherein the substrate is electrically connected to the metal frame through the plurality of conductive support structures.

[0053] like Figure 6 As shown, the back side of the substrate 110 is fixed to the side of the second chip 140 opposite to the metal frame 130, and the back side of the substrate 110 is fixed to the metal frame 130. The substrate 110 is electrically connected to the metal frame 130 through multiple conductive support structures 150.

[0054] Specifically, fixing the second surface of the substrate 110 to the side of the second chip 140 opposite to the metal frame 130 includes:

[0055] The back side of the substrate 110 is fixed to the side of the second chip 140 away from the metal frame 130 by conductive bumps 141. That is, the second chip 140 is mounted on the back side of the substrate 110 by flip-chip bonding. Of course, this embodiment does not specifically limit the method of mounting and fixing the second chip 140 to the back side of the substrate 110, and other methods besides flip-chip bonding can be used for chip mounting.

[0056] More specifically, fixing the second surface of the substrate 110 to the metal frame 130 includes:

[0057] The conductive support structure 150 is fixed to the back side of the substrate 110 through a hot-press reflow process, thereby fixing the back side of the substrate 110 to the metal frame 130. The multiple conductive support structures 150 serve two purposes: providing support and electrically connecting the metal frame 130 to the substrate 110.

[0058] In the above embodiments, multiple first chips are fixed to the first surface of the substrate, and multiple second chips are formed in a central region of the metal frame and stacked sequentially. Then, the second surface of the substrate is fixed to the side of the second chips away from the metal frame and to the metal frame, respectively. That is, the second chips are first fixed to the metal frame and then mounted on the second surface of the substrate. In this way, when multiple second chips are mounted on the second surface of the substrate, the metal frame and multiple conductive support structures provide good support for the substrate, which can effectively achieve chip mounting on the second surface of the substrate.

[0059] S140. Through a single molding process, a molding compound is formed on the first surface and the second surface of the substrate, respectively, and the molding compound encapsulates the first chip and the metal frame.

[0060] like Figure 7 As shown, after mounting the substrate 110 on both sides, a molding process is performed to form a molding compound 160 on the first and second surfaces of the substrate 110, respectively. The molding compound 160 encapsulates the first chip 120 and the metal frame 130.

[0061] Specifically, the chip-mounted substrate is placed into a molding die, with the metal frame 130 positioned as the bottom. Molding material is then injected, and through a single molding process, a molding compound 160 is formed on both the back and front sides of the substrate 110. The molding compound 160 encapsulates the first chip 120 and the metal frame 130. The molding compound 160 protects the substrate 110, the first chip 120, the second chip 140, the metal frame 130, and the multiple conductive support structures 150.

[0062] The encapsulation body 160 is formed only on the side of the metal frame 130 facing the substrate 110 and in the multiple openings formed after patterning; there is no encapsulation body 160 on the side of the metal frame 130 away from the substrate 110.

[0063] After molding the object to be molded to form a molded object 160, the entire substrate 110 is cut to form an independent encapsulation structure.

[0064] In the above embodiments, the metal frame 130 and multiple conductive support structures 150 can play a good role in supporting 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.

[0065] In the above embodiments, a single molding process is used to form a molding compound 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 frame 130 and multiple conductive support structures 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 frame 130, thereby avoiding damage to the first chip 120 and the second chip 140 caused by the impact of the molding compound, and improving the yield of the molded product.

[0066] For example, after forming the encapsulated body on the first and second surfaces of the substrate through a single encapsulation process, the method further includes:

[0067] like Figure 8 As shown, if the edge region of the patterned metal frame 130 is the metal frame 130, then a shielding layer 170 is formed around the first chip 120. The shielding layer 170 can prevent the first chip 120 from being subjected to electromagnetic interference.

[0068] Because the bottom edge of the package structure is a metal frame 130, that is, the bottom edge of the package structure is a metal layer, if a shielding layer 170 is formed around the entire package structure, the shielding layer 170 will cause a short circuit when it comes into contact with the metal frame 130 at the bottom edge of the package structure. Therefore, a shielding layer 170 is formed around each first chip 120.

[0069] The steps for forming the shielding layer 170 in the system-in-package structure can be as follows:

[0070] A through-groove is formed on the plastic package 160 surrounding the first chip 120 using a plastic encapsulation process. A metal layer is deposited in the through-groove using processes such as sputtering, thereby forming a shielding layer 170 surrounding the first chip 120.

[0071] For example, after forming the encapsulated body on the first and second surfaces of the substrate through a single encapsulation process, the method further includes:

[0072] like Figure 9As shown, if the edge region of the patterned metal frame 130 is a molding compound 160, a shielding layer 170 is formed around the molding compound. Only one side of the patterned metal frame 130 is left open for signal output. The shielding layer 170 can prevent the entire system-on-package structure from being subjected to electromagnetic interference.

[0073] Because the bottom edge of the package structure is a molding compound 160, which means that the bottom edge of the package structure is a molding material and not a metal material, a shielding layer 170 is formed around the molding compound 160. The contact between the shielding layer 170 and the bottom edge of the package structure is the molding compound 160 will not cause a short circuit.

[0074] The specific steps for forming a shielding layer 170 around the system-in-package structure can be as follows:

[0075] A through-groove is formed around the molded body 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 molded body 160. In other words, a shielding layer 170 is formed around the entire package structure, leaving only one side with the patterned metal frame 130 exposed for signal output.

[0076] For example, after forming the encapsulated body on the first and second surfaces of the substrate through a single encapsulation process, the method further includes:

[0077] A signal output layer (not shown) is formed on the side of the metal frame 130 opposite to the substrate 110.

[0078] A signal output layer (not shown) is formed on the side of the metal frame 130 facing away from the substrate 110 to bring out the signals of the system-in-package structure. Specifically, in this embodiment, a tin layer may be applied to the side of the metal frame 130 facing away from the substrate 110 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 disposed on the metal frame 130, etc.

[0079] In this embodiment, after the signal output layer is formed on the metal frame 130, 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.

[0080] In the above embodiments, since a molding compound 160 is formed in the multiple openings of the patterned metal frame 130, when a signal output layer is formed on the side of the metal frame 130 away from the substrate 110, the metal frame 130 on both sides of the opening can be prevented from short-circuiting due to the connection of the signal output layer, thus ensuring the performance of the packaging structure.

[0081] The system-level packaging method for double-sided molding of this embodiment fixes multiple first chips to the first surface of a substrate, forms multiple second chips stacked sequentially in the central region of a metal frame, and then fixes the second surface of the substrate to the side of the second chips away from the metal frame and the metal frame. The substrate is electrically connected to the metal frame through multiple conductive support structures. After fixing the second chips to the metal frame, the second chips are then mounted on the second surface of the substrate. Thus, when multiple second chips are mounted on the second surface of the substrate, the metal frame and the multiple conductive support structures provide excellent support for the substrate, enabling efficient chip mounting on the second surface. Furthermore, when cutting the substrate after double-sided mounting, the metal frame and the multiple conductive support structures provide excellent support, reducing cutting difficulty and preventing chip damage. The packaging method of this embodiment uses a single molding process to form a molding compound on both the first and second surfaces of the substrate, reducing warpage of the packaging structure and increasing its yield. The multiple second chips stacked sequentially in the central region of the metal frame provide heat dissipation for the multiple second chips.

[0082] 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.

[0083] 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 140 disposed on a second surface of the substrate 110, and a patterned metal frame 130 disposed on the side of the second chip 140 facing away from the substrate 110. The edge region of the metal frame 130 is provided with multiple conductive support structures 150. These multiple conductive support structures 150 serve both a supporting function and an electrical connection function.

[0084] It should be noted that the shape of the graphic metal frame 130 is not specifically limited in this embodiment, and can be selected according to actual needs. For example, the metal frame 130 can be the shape shown in the figure, or it can be the shape shown in the figure.

[0085] It should be further noted that, in this embodiment, the metal frame 130 is preferably made of copper, but other metal materials may also be used; this embodiment does not impose any specific limitations.

[0086] It should be noted that the conductive support structure 150 can be made of copper pillars or solder balls. Preferably, the conductive support structure 150 can be made of copper pillars or solder balls. As shown in the figure, in this embodiment, the conductive support structure 150 preferably uses solder balls.

[0087] 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 front surface of the substrate 110, and the second surface of the substrate 110 is used as the back surface of the substrate 110 for illustrative purposes. That is, a plurality of first chips 120 are fixed to the front surface of the substrate 110.

[0088] like Figure 10 and Figure 11 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 first chip 120 and the metal frame 130. The molding compound 160 encapsulates the first chip 120 and the metal frame 130 respectively. The molding compound 160 protects the substrate 110, the first chip 120, the second chip 140, the metal frame 130 and the multiple conductive support structures 150.

[0089] The encapsulation body 160 is formed only on the side of the metal frame 130 facing the substrate 110 and in the multiple openings formed after patterning; there is no encapsulation body 160 on the side of the metal frame 130 away from the substrate 110.

[0090] A single molding process is used to form a molding compound 160 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] For example, such as Figure 10 and Figure 11 As shown in this embodiment, the second chip 140 is flip-chip mounted on the second surface of the substrate 110 via conductive bumps 141. Of course, this embodiment does not specifically limit the method by which the second chip 140 is mounted and fixed on the back side of the substrate 110, and chip mounting can be performed using methods other than flip-chip mounting.

[0092] like Figure 10 and Figure 11 As shown, the encapsulation structure 100 also includes a shielding layer 170, such as... Figure 10 As shown, if the edge region of the patterned metal frame 130 is the metal frame 130, then the shielding layer 170 surrounds the first chip 120. The shielding layer 170 can prevent the first chip 120 from being subjected to electromagnetic interference.

[0093] like Figure 11As shown, if the edge region of the patterned metal frame 130 is the molding compound 160, then the shielding layer 170 is formed around the periphery of the molding compound 160. Only one side of the patterned metal frame 130 is left open for signal output. The shielding layer 170 can prevent the entire system-in-package structure from being subjected to electromagnetic interference.

[0094] The double-sided plastic-encapsulated system-in-package structure of this disclosure provides excellent support for the substrate when the patterned metal frame and multiple conductive support structures are mounted on the second surface of the substrate to mount the second chip. This allows for efficient 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 components provide excellent support for the substrate, reducing the difficulty of cutting and preventing damage to the chip. By using a single plastic encapsulation process to form the encapsulation body on both the first and second surfaces of the substrate, warpage of the package structure is reduced, and the yield of the package structure is increased. Placing the metal frame on the side of the second chip away from the substrate also helps to dissipate heat from the multiple second chips.

[0095] 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 is provided, and a plurality of first chips are fixed to a first surface of the substrate; A graphical metal frame is provided, in which a plurality of second chips are formed in sequence in the central region of the metal frame, and a plurality of conductive support structures are formed in the edge region of the metal frame; wherein, forming a plurality of conductive support structures in the edge region of the metal frame specifically includes: forming a plurality of fixing plates in the edge region of the metal frame; forming grooves in the fixing plates; and forming the corresponding conductive support structures in the grooves. The second surface of the substrate is fixed to the side of the second chip away from the metal frame and the metal frame, respectively, wherein the substrate is electrically connected to the metal frame through the plurality of conductive support structures; A molding process is used to form molding compounds on the first and second surfaces of the substrate, respectively, and the molding compounds encapsulate the first chip and the metal frame.

2. The method according to claim 1, characterized in that, The step of fixing the second surface of the substrate to the side of the second chip away from the metal frame includes: The second surface of the substrate is fixed to the side of the second chip away from the metal frame by conductive bumps.

3. The method according to claim 1, characterized in that, The step of fixing the second surface of the substrate to the metal frame includes: The conductive support structure is fixed to the second surface of the substrate by a hot-press reflow process, thereby fixing the second surface of the substrate to the metal frame.

4. The method according to any one of claims 1 to 3, characterized in that, After forming encapsulated bodies on the first and second surfaces of the substrate through a single encapsulation process, the method further includes: If the edge region of the graphical metal frame is the metal frame, then a shielding layer is formed around the first chip.

5. The method according to any one of claims 1 to 3, characterized in that, After forming encapsulated bodies on the first and second surfaces of the substrate through a single encapsulation process, the method further includes: If the edge region of the graphical metal frame is the encapsulated body, then a shielding layer is formed around the encapsulated body.

6. The method according to any one of claims 1 to 3, characterized in that, After forming encapsulated bodies on the first and second surfaces of the substrate through a single encapsulation process, the method further includes: A signal output layer is formed on the side of the metal frame opposite to the substrate.

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

8. The method according to any one of claims 1 to 3, characterized in that, The metal frame is made of copper.

9. A double-sided plastic-encapsulated system-in-package structure, formed by encapsulation using the encapsulation method described in any one of claims 1 to 8.

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