Epoxy plastic package structure for flip chip

Abstract

The utility model discloses an epoxy plastic package structure for a flip chip, which comprises a substrate, the top of the substrate is connected with the flip chip, and the flip chip is sealed on the substrate through an epoxy resin layer; wherein a first heat conduction layer is arranged between the flip chip and the epoxy resin layer, and a transition layer is arranged between the first heat conduction layer and the epoxy resin layer; a clamping part is arranged on the substrate, and the epoxy resin layer is connected to the clamping part; according to the epoxy plastic package structure of the flip chip, the heat dissipation efficiency of the epoxy resin layer can be effectively improved, heat accumulation in the chip can be reduced, the stability of the chip can be effectively maintained, and the service life of the chip can be prolonged.

Description

Technical Field

[0001] This utility model relates to the field of flip chip technology, specifically to an epoxy encapsulation structure for flip chips. Background Technology

[0002] In today's semiconductor industry, flip-chip packaging technology is widely used in various electronic devices, from smartphones and tablets to high-performance computers and automotive electronic systems, due to its advantages such as chip miniaturization and improved electrical performance. However, with the continuous increase in chip integration, the dramatic increase in the number of transistors per unit area, and the continuous increase in chip operating frequency, heat dissipation has become a key factor restricting the performance, reliability, and lifespan of flip-chips.

[0003] Chinese patent publication number CN213878077U discloses an epoxy encapsulation structure for flip chips, including a substrate, a chip on top of the substrate, solder balls on the bottom of the substrate, and an epoxy resin layer sealing the top of the substrate.

[0004] The aforementioned patents can solve the corresponding technical problems, but there are still drawbacks in actual use. In the use of the epoxy encapsulation structure for flip chips, the heat generated by the chip is dissipated to the outside through the epoxy resin layer. However, the epoxy resin itself has low thermal conductivity, which makes it difficult for the heat generated by the chip to be dissipated quickly through the epoxy resin layer. The heat accumulates inside the chip, which can easily cause the chip's operating temperature to rise sharply, reducing the chip's stability and lifespan. Utility Model Content

[0005] The purpose of this invention is to provide an epoxy encapsulation structure for flip chips, which solves the problem that in the existing epoxy encapsulation structure for flip chips, the heat generated by the chip is difficult to dissipate quickly through the epoxy resin layer, causing heat to accumulate inside the chip, which can lead to a sharp rise in the chip's operating temperature and reduce the chip's stability and lifespan.

[0006] To achieve the above objectives, the main technical solution adopted by this utility model includes: an epoxy encapsulation structure for flip chips, comprising: a substrate, a flip chip connected to the top of the substrate, the flip chip being sealed on the substrate by an epoxy resin layer; wherein, a first thermally conductive layer is provided between the flip chip and the epoxy resin layer, and a transition layer is provided between the first thermally conductive layer and the epoxy resin layer; a snap-fit ​​portion is provided on the substrate, the epoxy resin layer being connected to the snap-fit ​​portion; and multiple heat dissipation grooves are formed on the epoxy resin layer.

[0007] As a preferred technical solution, the first thermal conductive layer is a graphene thermal conductive coating, which is applied to the surface of the flip chip, and the thickness of the first thermal conductive layer is 20~30nm.

[0008] As a preferred technical solution, the transition layer is a silicon nitride coating, the transition layer is coated on the surface of the first thermally conductive layer, the transition layer is in direct contact with the epoxy resin layer, and the thickness of the transition layer is 15~30nm.

[0009] As a preferred technical solution, a solder pad is fixedly mounted on the top of the substrate, and a bump is fixedly mounted on the bottom of the flip chip, with the bump being soldered to the solder pad.

[0010] As a preferred technical solution, the snap-fit ​​portion includes a snap-fit ​​groove formed on the substrate, and a connecting pin is integrally formed on the epoxy resin layer, the connecting pin being fitted and installed inside the snap-fit ​​groove.

[0011] As a preferred technical solution, the substrate has multiple mounting holes, and a heat dissipation column is fixedly installed inside the mounting holes, with the upper end of the heat dissipation column in contact with the epoxy resin layer.

[0012] As a preferred technical solution, a second thermally conductive layer is provided between the upper end face of the heat dissipation column and the epoxy resin layer. The second thermally conductive layer is a graphene thermally conductive coating, and the thickness of the second thermally conductive layer is 20~30nm.

[0013] As a preferred technical solution, the heat dissipation column has a structure that is narrow at the top and wide at the bottom, and the heat dissipation column is made of copper.

[0014] As a preferred technical solution, the bottom of the substrate is integrally formed with a protrusion, and a heat dissipation channel is formed between the protrusion and the bottom of the substrate.

[0015] As a preferred technical solution, the substrate has injection molding holes.

[0016] This utility model has at least the following beneficial effects:

[0017] This invention provides an epoxy encapsulation structure for flip chips. The heat generated by the flip chip is first transferred to a first thermally conductive layer coated on the flip chip surface. This graphene-based first thermally conductive layer quickly transfers the heat generated by the flip chip to the epoxy resin layer via a transition layer. The silicon nitride transition layer reduces the thermal resistance at the interface, allowing heat to be smoothly transferred from the first thermally conductive layer to the epoxy resin layer. Upon receiving the heat from the first thermally conductive layer through the transition layer, the epoxy resin layer begins to diffuse the heat internally. Simultaneously, the epoxy resin layer... Multiple heat dissipation grooves are provided, which increase the contact area between the epoxy resin layer and the external environment. Heat is dissipated to the external environment through the surface of the heat dissipation grooves via thermal convection and thermal radiation. In addition, heat is efficiently conducted from the epoxy resin layer to the heat sink through the second thermally conductive layer made of graphene. The copper heat sink can quickly conduct heat downwards and dissipate heat into the surrounding air through thermal convection. This effectively improves the heat dissipation efficiency of the epoxy resin layer, reduces heat accumulation inside the chip, effectively maintains the stability of the chip, and increases its service life.

[0018] By uniformly filling the interior of the snap-fit ​​groove with epoxy resin, the snap-fit ​​groove on the substrate and the integrally molded epoxy resin connecting clip are sealed and snapped together, which can achieve a stable connection between the epoxy resin layer and the substrate, enhance the overall stability of the packaging structure, and prevent the epoxy resin layer from shifting or falling off. Attached Figure Description

[0019] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0020] Figure 1 This is a cross-sectional view of the epoxy encapsulation structure for flip chips according to this utility model;

[0021] Figure 2 For this utility model Figure 1 Enlarged schematic diagram of section A in the middle;

[0022] Figure 3 For this utility model Figure 1 Enlarged schematic diagram of section B in the middle.

[0023] Explanation of icon numbers:

[0024] 1. Substrate; 101. Soldering tab; 102. Mounting hole; 103. Snap-in groove; 104. Protrusion; 2. Flip chip; 3. Epoxy resin layer; 301. Connecting pin; 4. Bump; 5. First thermal conductive layer; 6. Transition layer; 7. Heat dissipation groove; 8. Heat dissipation pillar; 801. Second thermal conductive layer; 9. Injection hole. Detailed Implementation

[0025] The following will describe in detail the implementation of this application with reference to the accompanying drawings and embodiments, so that the implementation process of how this application uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0026] Example

[0027] Please refer to Figures 1 to 3 As shown, this embodiment provides an epoxy encapsulation structure for flip chips, including: a substrate 1, a flip chip 2 connected to the top of the substrate 1, the flip chip 2 being sealed on the substrate 1 by an epoxy resin layer 3; wherein, a first thermally conductive layer 5 is provided between the flip chip 2 and the epoxy resin layer 3, and a transition layer 6 is provided between the first thermally conductive layer 5 and the epoxy resin layer 3; a snap-fit ​​portion is provided on the substrate 1, and the epoxy resin layer 3 is connected to the snap-fit ​​portion; multiple heat dissipation grooves 7 are formed on the epoxy resin layer 3, which can effectively improve the heat dissipation efficiency of the epoxy resin layer, reduce heat accumulation inside the chip, effectively maintain the stability of the chip, and increase its service life.

[0028] The first thermally conductive layer 5 is a graphene thermally conductive coating. The first thermally conductive layer 5 is coated on the surface of the flip chip 2. The thickness of the first thermally conductive layer 5 is 20~30nm, preferably 25nm. By setting the graphene thermally conductive coating as the first thermally conductive layer 5 between the flip chip 2 and the epoxy resin layer 3, the high thermal conductivity of graphene is used to quickly dissipate the heat of the flip chip 2, thereby improving the heat dissipation performance of the flip chip 2, effectively reducing the operating temperature of the flip chip 2, avoiding problems such as performance degradation, unstable operation or even damage caused by overheating, and improving the reliability and service life of the flip chip 2.

[0029] The transition layer 6 is a silicon nitride coating. The transition layer 6 is coated on the surface of the first thermally conductive layer 5 and is in direct contact with the epoxy resin layer 3. The thickness of the transition layer 6 is 15~30nm, and the thickness of the transition layer 6 is preferably 20nm. By setting the transition layer 6 between the first thermally conductive layer 5 and the epoxy resin layer 3, the interfacial thermal resistance can be effectively reduced, and heat can be efficiently transferred to the epoxy resin layer 3.

[0030] The substrate 1 has a solder pad 101 fixedly mounted on its top, and the flip chip 2 has a bump 4 fixedly mounted on its bottom. The bump 4 is soldered to the solder pad 101. By soldering the solder pad 101 on the top of the substrate 1 to the bump 4 on the bottom of the flip chip 2, the electrical and mechanical connection between the flip chip 2 and the substrate 1 can be ensured to be stable and reliable.

[0031] The snap-fit ​​portion includes a snap-fit ​​groove 103 formed on the substrate 1, and a connecting snap-fit ​​foot 301 integrally formed on the epoxy resin layer 3. The connecting snap-fit ​​foot 301 is fitted into the inside of the snap-fit ​​groove 103. By setting the snap-fit ​​groove 103 on the substrate 1 and fitting the connecting snap-fit ​​foot 301 of the epoxy resin layer 3, a stable connection between the epoxy resin layer 3 and the substrate 1 can be achieved, enhancing the overall stability of the packaging structure and preventing the epoxy resin layer 3 from shifting or falling off.

[0032] The substrate 1 has multiple mounting holes 102, and heat sinks 8 are fixedly installed inside the mounting holes 102. The upper end of the heat sink 8 is in contact with the epoxy resin layer 3. By having the heat sink 8 in contact with the epoxy resin layer 3, the heat dissipation efficiency of the flip chip 2 can be further improved.

[0033] A second thermally conductive layer 801 is provided between the upper end face of the heat dissipation column 8 and the epoxy resin layer 3. The second thermally conductive layer 801 is a graphene thermally conductive coating. The thickness of the second thermally conductive layer 801 is 20~30nm, preferably 25nm, which can effectively enhance the heat conduction between the heat dissipation column 8 and the epoxy resin layer 3.

[0034] Among them, the heat dissipation column 8 has a structure that is narrow at the top and wide at the bottom, and the heat dissipation column 8 is made of copper. By adopting the design of copper material that is narrow at the top and wide at the bottom, the heat dissipation column 8 can accelerate heat conduction, and the structure that is narrow at the top and wide at the bottom increases the contact area with the air and improves heat dissipation efficiency.

[0035] The bottom of the substrate 1 is integrally formed with a protrusion 104, and a heat dissipation channel is formed between the protrusion 104 and the bottom of the substrate 1. By forming a heat dissipation channel between the protrusion 104 and the bottom of the substrate 1, air convection heat dissipation is promoted.

[0036] The substrate 1 has injection holes 9. By opening injection holes 9 on the substrate 1, it is convenient to inject epoxy resin during the packaging process, ensuring uniform filling of epoxy resin, and improving packaging quality and production efficiency.

[0037] Working principle:

[0038] When the flip chip 2 is working, the heat generated is first transferred to the first thermally conductive layer 5 coated on the surface of the flip chip 2. The graphene-based first thermally conductive layer 5 can quickly transfer the heat generated by the flip chip 2 to the epoxy resin layer 3 via the transition layer 6. The silicon nitride-based transition layer 6 can reduce the thermal resistance at the interface, allowing the heat to be smoothly transferred from the first thermally conductive layer 5 to the epoxy resin layer 3. After receiving the heat from the first thermally conductive layer 5 through the transition layer 6, the epoxy resin layer 3 begins to diffuse the heat within itself. At the same time, multiple heat dissipation grooves 7 are formed on the epoxy resin layer 3. These heat dissipation grooves 7 increase the contact area between the epoxy resin layer 3 and the external environment. The heat will be dissipated to the external environment through the surface of the heat dissipation grooves 7 in the form of thermal convection and thermal radiation. In addition, the heat is efficiently conducted from the epoxy resin layer 3 to the heat dissipation column 8 through the graphene-based second thermally conductive layer 801. The copper-based heat dissipation column 8 can quickly conduct the heat downward and dissipate the heat into the surrounding air through thermal convection.

[0039] During the flip chip 2 packaging process, epoxy resin is injected through the injection hole 9, so that the injected epoxy resin is evenly filled into the interior of the snap-fit ​​groove 103, so that the snap-fit ​​groove 103 on the substrate 1 and the integrally molded epoxy resin connecting clip 301 are sealed and snapped together, which can realize the stable connection between the epoxy resin layer 3 and the substrate 1, enhance the overall stability of the packaging structure, and prevent the epoxy resin layer 3 from shifting or falling off.

[0040] The foregoing description illustrates and describes several preferred embodiments of the present invention. However, as previously stated, it should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the inventive concept described herein through the foregoing teachings or techniques or knowledge in related fields. Any modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. An epoxy encapsulation structure for flip chips, characterized in that, include: A substrate (1) has a flip chip (2) connected to its top, and the flip chip (2) is sealed on the substrate (1) by an epoxy resin layer (3). A first thermally conductive layer (5) is provided between the flip chip (2) and the epoxy resin layer (3), and a transition layer (6) is provided between the first thermally conductive layer (5) and the epoxy resin layer (3). The substrate (1) is provided with a snap-fit ​​part, and the epoxy resin layer (3) is connected to the snap-fit ​​part; Multiple heat dissipation grooves (7) are provided on the epoxy resin layer (3).

2. The epoxy encapsulation structure for flip chips according to claim 1, characterized in that: The first thermal conductive layer (5) is a graphene thermal conductive coating. The first thermal conductive layer (5) is coated on the surface of the flip chip (2). The thickness of the first thermal conductive layer (5) is 20~30nm.

3. The epoxy encapsulation structure for flip chips according to claim 2, characterized in that: The transition layer (6) is a silicon nitride coating. The transition layer (6) is coated on the surface of the first thermally conductive layer (5). The transition layer (6) is in direct contact with the epoxy resin layer (3). The thickness of the transition layer (6) is 15~30nm.

4. The epoxy encapsulation structure for flip chips according to claim 1, characterized in that: A solder pad (101) is fixedly mounted on the top of the substrate (1), and a bump (4) is fixedly mounted on the bottom of the flip chip (2). The bump (4) is soldered to the solder pad (101).

5. The epoxy encapsulation structure for flip chips according to claim 1, characterized in that: The snap-fit ​​portion includes a snap-fit ​​groove (103) formed on the substrate (1), and a connecting pin (301) integrally formed on the epoxy resin layer (3), and the connecting pin (301) is fitted into the inside of the snap-fit ​​groove (103).

6. An epoxy encapsulation structure for flip chips according to claim 5, characterized in that: The substrate (1) has multiple mounting holes (102), and heat dissipation columns (8) are fixedly installed inside the mounting holes (102). The upper end of the heat dissipation column (8) is in contact with the epoxy resin layer (3).

7. An epoxy encapsulation structure for flip chips according to claim 6, characterized in that: A second thermally conductive layer (801) is provided between the upper end face of the heat dissipation column (8) and the epoxy resin layer (3). The second thermally conductive layer (801) is a graphene thermally conductive coating, and the thickness of the second thermally conductive layer (801) is 20~30nm.

8. An epoxy encapsulation structure for flip chips according to claim 7, characterized in that: The heat dissipation column (8) has a structure that is narrow at the top and wide at the bottom, and the heat dissipation column (8) is made of copper.

9. An epoxy encapsulation structure for flip chips according to claim 1, characterized in that: The bottom of the substrate (1) is integrally formed with a protrusion (104), and a heat dissipation channel is formed between the protrusion (104) and the bottom of the substrate (1).

10. An epoxy encapsulation structure for flip chips according to claim 7, characterized in that: The substrate (1) has injection holes (9).

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