Chip package structure with improved heat dissipation performance

Abstract

The utility model relates to the field of chip packaging structure, concretely relates to a chip packaging structure of improving heat dissipation performance, including chip, base plate, heat dissipation cover, plastic package layer and solder ball array, chip installs on base plate, heat dissipation cover is equipped with mould pressing surface and connecting surface, heat dissipation cover includes main part and sets up in the anti -overflow structure of the outer periphery of main part, the anti -overflow structure includes the limiting portion set up on the main part, is equipped with the annular setting of overflow groove around plastic package layer on the limiting portion, mould pressing mould pushes limiting portion to move to the heat dissipation cover and base plate between and forms the close space of holding, make plastic package layer be located in the holding space. Through the setting of anti -overflow structure, make mould pressing time, the plastic package layer of flowing state not easy along the sidewall of heat dissipation cover climbs to the surface on heat dissipation cover, but is located in the holding space formed between heat dissipation cover and base plate, thereby reduces the condition that the heat dissipation efficiency reduces because of the overflow of plastic package layer to the top surface on heat dissipation cover, improves heat dissipation efficiency.

Description

Technical Field

[0001] This utility model relates to the field of chip packaging structure, and specifically to a chip packaging structure that improves heat dissipation performance. Background Technology

[0002] Ball Grid Array (BGA) packaging is a surface-mount packaging technology that replaces traditional pins with spherical contacts arranged at the bottom of the package. These spherical contacts connect to pads on the printed circuit board. BGA packaging offers high density, high-speed transmission, and excellent heat dissipation, making it widely used in high-performance electronic devices. Heat dissipation in BGA packages typically relies on a heat sink. This heat sink is usually designed with recesses in the packaging mold. During injection molding, the top surface of the heat sink contacts the mold and, driven by the mold, adheres to the molding compound, awaiting curing of the molding compound to complete the injection molding process.

[0003] However, the above-mentioned chip packaging structure has the following problems: When the heat sink is molded onto the molding compound, the molding compound is in an unsolidified state and has strong fluidity under pressure. When the heat sink is molded, the molding compound is prone to climbing up the side wall of the heat sink to the surface of the top of the heat sink. The surface of the top of the heat sink is in contact with the outside air, and the contact area between the surface of the top of the heat sink and the outside air has a great influence on the effective heat dissipation area of ​​the heat sink. In the above-mentioned chip packaging structure, the molding compound climbing up the side wall of the heat sink to the surface of the top of the heat sink reduces the effective heat dissipation area of ​​the heat sink, which may affect the heat dissipation efficiency of the heat sink. Utility Model Content

[0004] The technical solution adopted by this utility model to solve its technical problem is: to provide a chip packaging structure with improved heat dissipation performance, including a chip, a substrate, a heat sink, a molding compound, and a solder ball array disposed on the bottom of the substrate. The chip is mounted on the substrate, the molding compound is disposed on the substrate and the molding compound completely covers the outer surface of the chip, the heat sink is disposed on the molding compound, the heat sink has a molding surface and a connecting surface, the molding surface corresponds to the molding die, after molding, the molding surface is in contact with the outside air, the connecting surface and the molding compound are bonded to each other, and the substrate is connected to the PCB board through the solder ball array;

[0005] The heat dissipation cover includes a main body and an anti-overflow structure disposed on the outer periphery of the main body. The anti-overflow structure includes a limiting part disposed on the main body. The limiting part is provided with an overflow groove arranged in annularly around the outer periphery of the plastic seal layer. During molding, the molding die pushes the limiting part to move between the heat dissipation cover and the substrate to form a sealed accommodating space, so that the plastic seal layer is located in the accommodating space.

[0006] Furthermore, multiple overflow grooves are arranged side by side along the radial direction of the heat dissipation cover, and all of the multiple overflow grooves are interconnected.

[0007] Furthermore, the cross-sectional area of ​​the plurality of overflow grooves decreases sequentially along the radial direction of the heat dissipation cover, and the cross-sectional area of ​​the overflow groove closer to the center of the heat dissipation cover is greater than that of the overflow groove farther from the center of the heat dissipation cover.

[0008] Furthermore, the area of ​​the main body is larger than the area of ​​the chip.

[0009] Furthermore, both the molding surface and the connecting surface are located on the main body.

[0010] Furthermore, a conical groove is formed at the center of the molding surface, the maximum cross-sectional area of ​​the conical groove is smaller than the cross-sectional area of ​​the molding surface, and the maximum cross-sectional area of ​​the conical groove is adapted to the outer surface of the chip.

[0011] Furthermore, the connecting surface is provided with multiple heat dissipation protrusions, which penetrate the plastic sealing layer.

[0012] Furthermore, the end of the heat dissipation protrusion has a hemispherical structure.

[0013] The beneficial effects of this utility model are: by setting the anti-overflow structure, the plastic sealant in the flow state is not easy to climb up the side wall of the heat sink cover to the surface of the heat sink cover during molding, but is located in the accommodating space formed between the heat sink cover and the substrate, thereby reducing the reduction of heat dissipation efficiency caused by the plastic sealant overflowing to the top surface of the heat sink cover, and improving heat dissipation efficiency. Attached Figure Description

[0014] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0015] In the picture: Figure 1 An overall structural diagram of a chip packaging structure for improving heat dissipation performance provided by this utility model;

[0016] Figure 2 for Figure 1 The three-dimensional structure diagram of the chip packaging structure for improving heat dissipation performance is shown from another perspective.

[0017] Figure 3 for Figure 1 An exploded view of a chip packaging structure designed to improve heat dissipation.

[0018] Figure 4 for Figure 1 A cross-sectional view of a chip packaging structure designed to improve heat dissipation performance;

[0019] Figure 5 for Figure 4 Enlarged view of point A in the middle.

[0020] Explanation of reference numerals in the attached figures: 100, chip packaging structure for improved heat dissipation; 10, chip; 20, substrate; 30, heat sink cover; 31, molding surface; 311, conical groove; 32, connecting surface; 321, heat dissipation protrusion; 33, main body; 34, limiting part; 341, overflow groove; 342, skirt part; 40, solder ball array. Detailed Implementation

[0021] To make the technical problem to be solved, the technical solution, and the beneficial effects of this utility model clearer, the present utility model will now be described in detail with reference to the accompanying drawings. This drawing is a simplified schematic diagram, illustrating only the basic aspects of the present utility model, and therefore only shows the components relevant to the present utility model. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0022] Please refer to Figure 1 and Figure 2 This invention provides a chip packaging structure 100 for improving heat dissipation performance, including a chip 10, a substrate 20, a heat sink 30, a molding compound, and a solder ball array 40 disposed on the bottom of the substrate 20 (the molding compound is not shown in the figure). The chip 10 is mounted on the substrate 20, the molding compound is disposed on the substrate 20 and completely covers the outer surface of the chip 10, the heat sink 30 is disposed on the molding compound, and the heat sink 30 has a molding surface 31 and a connecting surface 32. The molding surface 31 corresponds to the molding die. After molding, the molding surface 31 is in contact with the outside air, and the connecting surface 32 is bonded to the molding compound. The substrate 20 is connected to the PCB board through the solder ball array 40. Specifically, the chip 10 is connected to the substrate 20 by gold wire bonding, the molding compound is pre-coated with thermally conductive adhesive, and the connecting surface 32 of the heat sink 30 is bonded to the molding compound through the thermally conductive adhesive.

[0023] Please refer to Figure 4 and Figure 5The heat sink 30 includes a main body 33 and an anti-overflow structure disposed on the outer periphery of the main body 33. The anti-overflow structure includes a limiting part 34 disposed on the main body 33, and an overflow groove 341 annularly disposed around the outer periphery of the molding compound. During molding, the molding die pushes the end of the limiting part 34 to move to form a sealed accommodating space between the heat sink 30 and the substrate 20, so that the molding compound is located within the accommodating space. During molding, the molding compound is squeezed and deformed, and the edge of the molding compound gradually moves away from the center of the chip 10, and is eventually blocked by the overflow groove 341 on the limiting part 34. By setting the anti-overflow structure, during molding, the flowing molding compound is less likely to climb up the side wall of the heat sink 30 to the surface of the heat sink 30, but is located within the accommodating space formed between the heat sink 30 and the substrate 20, thereby reducing the reduction in heat dissipation efficiency caused by the molding compound overflowing to the top surface of the heat sink 30, and improving heat dissipation efficiency.

[0024] To ensure sufficient contact area between the main body 33 and the chip 10, thereby guaranteeing efficient heat dissipation from the main body 33 to the chip 10, the area of ​​the main body 33 is larger than the area of ​​the chip 10. Specifically, in this embodiment, the entire heat sink 30 is made of a metal or metal alloy with good heat dissipation performance, such as copper and aluminum alloy. The cross-section of the heat sink 30 is circular, and the square structure formed by the cross-section of the chip 10 is located within the circular trajectory formed by the cross-section of the main body 33.

[0025] Multiple overflow grooves 341 are arranged side by side along the radial direction of the heat dissipation cover 30, and all the overflow grooves 341 are interconnected. The arrangement of multiple overflow grooves 341 increases the amount of overflowing plastic sealant that can be retained.

[0026] For details, please refer to Figure 4 and Figure 5 The cross-sectional area of ​​the multiple overflow grooves 341 decreases sequentially along the radial direction of the heat sink 30, with the cross-sectional area of ​​the overflow groove 341 closer to the center of the heat sink 30 being larger than that of the overflow groove 341 farther from the center of the heat sink 30. Specifically, in this embodiment, the limiting part 34 is an annular structure surrounding the outer periphery of the plastic seal layer, and a skirt part 342 extends outward from the outer periphery of the limiting part 34. The height of the skirt part 342 along the thickness direction of the chip 10 is less than the height of the limiting part 34 along the thickness direction of the chip 10, and the overall cross-section of the limiting part 34 and the skirt part 342 presents an L-shaped structure. The multiple overflow grooves 341 extend from the inner wall of the limiting part 34 to the inner wall of the skirt part 342. The skirt part 342 can facilitate the reservation of sufficient space for opening the overflow grooves 341 in the radial direction of the heat sink 30 while reducing the waste of space in the thickness direction of the chip 10, thereby reducing the overall volume occupied by the chip 10 packaging structure.

[0027] Since the amount of overflow of the molding compound gradually decreases from the center of the heat sink 30 to the surrounding area, the cross-sectional area of ​​the corresponding overflow groove 341 also gradually decreases from the center of the heat sink 30 to the surrounding area, thereby reducing space waste, reducing the overall volume of the chip 10 package structure, and optimizing space design.

[0028] Please refer to Figure 4 Both the molding surface 31 and the connecting surface 32 are located on the main body 33. A conical groove 311 is formed at the center of the molding surface 31. To ensure the contact area between the molding die and the heat sink 30, so that the molding die can apply force to the heat sink 30, the maximum cross-sectional area of ​​the conical groove 311 is smaller than the cross-sectional area of ​​the molding surface 31. It can be understood that the cross-sectional area of ​​the molding surface 31 mentioned here is indirectly equivalent to the effective heat dissipation area of ​​the heat sink 30, and the maximum cross-sectional area of ​​the conical groove 311 is the cross-sectional area at the opening of the conical groove 311. Specifically, the maximum cross-sectional area of ​​the conical groove 311 is adapted to the outer surface of the chip 10. By setting the conical groove 311, the heat dissipation path between the chip 10 and the outside air is shortened, thereby facilitating the heat sink 30 to dissipate heat from the chip 10 and further improving the heat dissipation efficiency.

[0029] Please refer to Figure 3 and Figure 4 The connection surface 32 is provided with multiple heat dissipation protrusions 321, which penetrate into the molding compound. By setting multiple heat dissipation protrusions 321, the distance between the outer surface of the chip 10 and the outside air is shortened, thereby further improving the heat dissipation efficiency of the chip 10.

[0030] For details, please refer to Figure 4 The end of the heat dissipation protrusion 321 is a hemispherical structure. The hemispherical structure reduces the cross-sectional area of ​​the end of the heat dissipation protrusion 321, making it easier for the heat dissipation protrusion 321 to penetrate the molding layer and approach the outer surface of the chip 10.

Claims

1. A chip packaging structure for improving heat dissipation performance, characterized in that, The device includes a chip, a substrate, a heat sink, a molding compound, and a solder ball array disposed on the bottom of the substrate. The chip is mounted on the substrate, the molding compound is disposed on the substrate and completely covers the outer surface of the chip, the heat sink is disposed on the molding compound, and the heat sink has a molding surface and a connecting surface. The molding surface corresponds to a molding die. After molding, the molding surface is in contact with the outside air, the connecting surface is bonded to the molding compound, and the substrate is connected to a PCB board through the solder ball array. The heat dissipation cover includes a main body and an anti-overflow structure disposed on the outer periphery of the main body. The anti-overflow structure includes a limiting part disposed on the main body. The limiting part is provided with an overflow groove arranged in annularly around the outer periphery of the plastic seal layer. During molding, the molding die pushes the limiting part to move between the heat dissipation cover and the substrate to form a sealed accommodating space, so that the plastic seal layer is located in the accommodating space.

2. The chip packaging structure for improving heat dissipation performance according to claim 1, characterized in that: Multiple overflow slots are arranged side by side along the radial direction of the heat dissipation cover, and all of the multiple overflow slots are interconnected.

3. The chip packaging structure for improving heat dissipation performance according to claim 2, characterized in that: The cross-sectional area of ​​the multiple overflow slots decreases sequentially along the radial direction of the heat sink cover, and the cross-sectional area of ​​the overflow slots closer to the center of the heat sink cover is greater than that of the overflow slots farther away from the center of the heat sink cover.

4. The chip packaging structure for improving heat dissipation performance according to claim 1, characterized in that: The area of ​​the main body is larger than the area of ​​the chip.

5. The chip packaging structure for improving heat dissipation performance according to claim 1, characterized in that: Both the molding surface and the connecting surface are located on the main body.

6. The chip packaging structure for improving heat dissipation performance according to claim 1, characterized in that: A conical groove is formed at the center of the molding surface. The maximum cross-sectional area of ​​the conical groove is smaller than the cross-sectional area of ​​the molding surface. The maximum cross-sectional area of ​​the conical groove is adapted to the outer surface of the chip.

7. The chip packaging structure for improving heat dissipation performance according to claim 1, characterized in that: The connecting surface is provided with multiple heat dissipation protrusions, which penetrate into the plastic sealing layer.

8. The chip packaging structure for improving heat dissipation performance according to claim 7, characterized in that: The end of the heat dissipation protrusion has a hemispherical structure.

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