Chip heat dissipation structure and preparation method thereof

Abstract

The application discloses a chip heat dissipation structure and a preparation method thereof, and comprises: a shielding cover arranged on a substrate, the shielding cover is composed of a side wall and a top plate, the side wall surrounds the outside of a chip to form a frame structure, the bottom of the side wall is connected with the substrate, and the top plate closes the opening of the side wall; and the application further comprises a diffusion piece arranged on the top surface of the top plate. The application can be applied to the multilayer chip shielding structure designed by the inventor, the shielding structure comprises an inhibition layer, an absorption layer and a reflection layer from inside to outside, the reflection layer is located at the outermost side of the shielding cover, and the reflection layer is made of high-conductivity metal, so that the reflection layer has a large processing space. Taking FIG. 2 as an example, the diffusion piece is arranged on the top plate of the shielding cover, so that the heat dissipation area is effectively increased, and the heat dissipation efficiency is improved; and the top plate and the side wall are both designed in a multilayer shielding structure, so that the shielding effect is ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of shielding covers, and more particularly to a chip heat dissipation structure and a preparation method thereof. BACKGROUND

[0002] With the popularity of 5G communication, Internet of Things and high-frequency electronic devices, electromagnetic interference (EMI) problems are becoming increasingly prominent. In the prior art, the shielding structure of the chip mainly includes: a single-layer metal shielding cover: the electromagnetic shielding structure mentioned in the patent with the patent number 202210635054.X. A plastic sealing shielding layer: the chip packaging structure mentioned in the patent with the patent number 202323168414.9 of Weijiechuangxin. A composite shielding material: the composite material mentioned in the patent with the patent number 201810004138.7 of Shandong Lutaichushi Group Co., Ltd. Graphene polymer composite material research center.

[0003] However, the above three shielding structures all have defects, for example: the single-layer shielding structure has limited shielding efficiency for high-frequency signals and cannot cope with multi-band electromagnetic interference; the multi-layer interconnection structure of the plastic sealing shielding layer complicates the processing technology, has low heat dissipation efficiency, is prone to cause heat accumulation, and is difficult to cope with multi-band interference; the shielding effect of the composite material is excellent, but the shielding waveband range is narrow. In order to combine the shielding advantages of the above three and overcome their respective defects, the inventors provide a multi-layer chip shielding structure, which covers the chip with a three-layer structure of a suppression layer, an absorption layer and a reflection layer, thereby realizing the effect of multi-band shielding. However, in actual use, because a multi-layer structure is adopted, the heat dissipation efficiency is similar to that of the plastic sealing shielding layer, and heat accumulation phenomenon still occurs during long-term use, so how to solve the heat dissipation problem is a technical problem to be solved by the present application. SUMMARY

[0004] A series of simplified concepts are introduced in the summary section, which will be further described in detail in the specific embodiment section. The summary section of the present application does not mean to attempt to limit the key features and necessary technical features of the claimed technical solution, and even less to determine the protection scope of the claimed technical solution.

[0005] To at least partially solve the above problems, the present application provides a chip heat dissipation structure, comprising: a shielding cover arranged on a substrate, the shielding cover being composed of a side wall and a top plate, the side wall surrounding the outside of the chip to form a frame-shaped structure, the bottom of the side wall being connected with the substrate, and the top plate closing the opening of the side wall, and further comprising a diffusion member arranged on the top surface of the top plate.

[0006] Preferably, the bottom surface of the top plate covers the top surface of the side wall, the bottom surface of the top plate is provided with a heat-conducting member, and extends into the opening of the side wall, the bottom of the heat-conducting member is connected to or abuts against the top of the chip, the top of the heat-conducting member is connected to the bottom surface of the top plate, and the diffusion member is arranged on the top surface of the top plate.

[0007] Preferably, the diffusion member is composed of a plurality of heat dissipation blocks, each of the heat dissipation blocks has a connecting surface, a heat dissipation surface, and at least three side wall surfaces, the connecting surface and the heat dissipation surface are located on two opposite surfaces, the connecting surface and the heat dissipation surface are connected by the side wall surfaces, the side wall surfaces are arranged in a vertical direction, the connecting surface is a bottom surface and is arranged in a horizontal direction, the heat dissipation block is connected to the top surface of the top plate by the connecting surface, and the connecting surface and the heat dissipation surface have a non-zero included angle a.

[0008] Preferably, the non-zero included angles a of the heat dissipation blocks arranged on the top surface of the top plate are in the same direction.

[0009] Preferably, two limiting tables are symmetrically arranged in the opening of the side wall, a first distance is reserved between the two limiting tables, the first distance is adapted to the size of the chip, the heat-conducting member is arranged in the opening of the side wall, the bottom surface of the heat-conducting member is connected to the top surface of the limiting table, the top plate is arranged in the opening of the side wall, the shape of the top plate is adapted to the shape of the opening of the side wall, and the bottom surface of the top plate is connected to the top surface of the heat-conducting member.

[0010] Preferably, a through hole is arranged on the heat-conducting member, the opening area of the through hole is not greater than the surface area of the chip, and the through hole is filled with magnetic nanofluid.

[0011] Preferably, the top surface of the limiting table is provided with a limiting groove, the bottom surface of the heat-conducting member is provided with a limiting member, and the heat-conducting member is connected to the limiting table by cooperation between the limiting member and the limiting groove.

[0012] Preferably, a second distance is reserved between the bottom surface of the heat-conducting member and the top surface of the chip, and the bottom surface of the heat-conducting member and the top surface of the chip are filled with magnetic nanofluid.

[0013] Preferably, a threaded groove is arranged in the opening of the side wall, the top surface of the top plate is provided with an exchanger in communication with a circulating device, and the exchanger is threadedly connected to the threaded groove.

[0014] A preparation method of the chip heat dissipation structure, steps are as follows,

[0015] S1: a top plate with shielding effect is manufactured by using the same process as the side wall;

[0016] S2: a stamping die is prepared;

[0017] S3: the diffusion member is manufactured on the top surface of the top plate by hot pressing of the stamping die.

[0018] Compared with the prior art, the present application at least includes the following beneficial effects:

[0019] The present application can be applied to the multi-layer chip shielding structure designed by the inventor, as shown in Figure 2 , Figure 2 is a cross-sectional view of the multi-layer chip shielding structure, which can be covered on the chip as a cover, and the shielding structure is composed of a suppression layer, an absorption layer and a reflection layer from inside to outside. Because the reflection layer is located at the outermost side of the shielding cover, and the reflection layer is made of high-conductive metal, it has a larger processing space. For example, Figure 2 , the diffusion member is arranged on the top plate of the shielding cover, which can effectively increase the heat dissipation area and improve the heat dissipation efficiency. However, because the reflection layer is a metal deposited by magnetron sputtering process, it is usually integrally formed with the top plate and the side wall. If the diffusion member is processed on the top plate, the process is difficult. Therefore, according to the design idea in the patent No. 202210635054.X of Huawei, a structure design as shown in Figure 1 is adopted to form a fence around the outside of the chip with the side wall, and then the top plate is produced and processed separately. The processing of the diffusion member on the top plate is simpler than the direct processing on the shielding cover. The top plate and the side wall are both designed with multi-layer shielding structure to ensure the shielding effect.

[0020] The chip heat dissipation structure and the preparation method thereof, other advantages, objects and features of the present application will be embodied in part through the following description, and part will be understood by those skilled in the art through research and practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0021] The accompanying drawings are included to provide a further understanding of the present application, and constitute a part of the specification, which together with the embodiments of the present application, is used to explain the present application, and does not constitute a limitation on the present application. In the drawings:

[0022] Figure 1 is an exploded view of the shielding structure mentioned in the background art.

[0023] Figure 2 is a position diagram of the diffusion member.

[0024] Figure 3 is a schematic diagram of the diffusion member applied to the prior art.

[0025] Figure 4 is a structure diagram of the heat dissipation block (three side wall surfaces).

[0026] Figure 5 is a front view of the heat dissipation block (three side wall surfaces).

[0027] Figure 6 This is a schematic diagram of the heat sink (five side walls).

[0028] Figure 7 This is a schematic diagram of a diffuser (the heat sink has five sidewalls).

[0029] Figure 8 A schematic diagram of the chip heat dissipation structure of the present invention with a switch (the substrate and diffuser are not shown).

[0030] Figure 9 for Figure 8 Sectional view of AA.

[0031] Figure 10 for Figure 8 A cross-sectional view of BB.

[0032] Figure 11 for Figure 8 Exploded view.

[0033] In the figure: 1 substrate, 2 shielding cover, 21 side wall, 22 top plate, 3 chip, 4 diffuser, 5 heat conduction component, 51 through hole, 52 limiting component, 6 heat sink, 61 connecting surface, 62 heat dissipation surface, 63 side wall surface, 7 limiting stage, 71 limiting groove, 8 exchanger. Detailed Implementation

[0034] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments, so that those skilled in the art can implement it based on the description.

[0035] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0036] like Figures 1-11 As shown, this invention provides a chip heat dissipation structure, including: a shielding cover 2 disposed on a substrate 1, the shielding cover 2 consisting of sidewalls 21 and a top plate 22, the sidewalls 21 surrounding the outside of a chip 3 to form a frame structure, the bottom of the sidewalls 21 being connected to the substrate 1, and the top plate 22 sealing the opening of the sidewalls 21; and a diffuser 4 disposed on the top surface of the top plate 22. This allows the invention to be applied to multi-layer chip shielding structures designed by the inventors, such as... Figure 2 As shown, Figure 2 This is a cross-sectional view of a multi-layer chip shielding structure. The shielding structure, acting as a cover, can enclose the chip. From the inside out, the shielding structure consists of an inhibition layer, an absorption layer, and a reflective layer. Because the reflective layer is located on the outermost side of the shielding cover 2 and is made of a highly conductive metal, it has a large processing space. Figure 2For example, the diffusion member 4 is arranged on the top plate 22 of the shielding cover 2, which can effectively increase the heat dissipation area and improve the heat dissipation efficiency. However, because the reflection layer is a metal deposited by a magnetron sputtering process, it is usually integrated with the top plate 22 and the side wall 21. If the diffusion member 4 is to be processed on the top plate 22, the process is difficult.

[0037] Therefore, according to the design idea of Huawei in the patent with the patent number 202210635054.X, a structure design as shown in Figure 1 is adopted. The bottom surface of the top plate 22 covers the top surface of the side wall 21. The bottom surface of the top plate 22 is provided with a heat conduction member 5, which extends into the opening of the side wall 21. The bottom of the heat conduction member 5 is connected or abuts against the top of the chip 3. The top of the heat conduction member 5 is connected with the bottom surface of the top plate 22. The diffusion member 4 is arranged on the top surface of the top plate 22. The side wall 21 forms a fence surrounding the outside of the chip 3. Then, the top plate 22 is produced and processed separately. The top plate 22 is processed with the diffusion member 4 separately. The processing technology is simpler than directly processing on the shielding cover 2. The top plate 22 and the side wall 21 both adopt a multi-layer shielding structure design to ensure the shielding effect.

[0038] The diffusion member 4 is composed of a plurality of heat dissipation blocks 6, as shown in Figure 7 The heat dissipation block 6 has a connecting surface 61, a heat dissipation surface 62, and at least three side wall surfaces 63. The connecting surface 61 (bottom surface) and the heat dissipation surface 62 (top surface) are located on two opposite surfaces. The connecting surface 61 and the heat dissipation surface 62 are connected through the side wall surface 63. The side wall surface 63 is arranged in the vertical direction. The connecting surface 61 is the bottom surface and is arranged in the horizontal direction. The heat dissipation block 6 is connected with the top surface of the top plate 22 through the connecting surface 61. The connecting surface 61 and the heat dissipation surface 62 have a non-zero included angle a. The opening direction of the non-zero included angle a of the heat dissipation block 6 arranged on the top surface of the top plate 22 is consistent.

[0039] When the number of side wall surfaces 63 is three, as shown in Figure 4 , the top view of the heat dissipation block 6 is rectangular, and the front view is triangular. At this time, the diffusion member 4 is composed of a plurality of heat dissipation blocks 6 arranged in parallel. Because the opening direction of the non-zero included angle a is consistent, when the number of side wall surfaces 63 is three, only the heat dissipation surface 62 and one side wall surface 63 are actually involved in heat dissipation. The side wall surface 63 is the side wall surface opposite to the non-zero included angle a, as shown in Figure 4 and Figure 5 .

[0040] Since the number of side wall surfaces 63 also affects the heat dissipation area, as the most preferred, the number of side wall surfaces 63 is five. At this time, the top view of the heat dissipation block 6 is hexagonal, as shown in Figure 6 At this time, when the heat dissipation block 6 forms the diffusion member 4, the five side wall surfaces 63 can all participate in heat dissipation, as shown inFigure 7 Further, the heat dissipation efficiency can be greatly improved.

[0041] A preparation method of a chip heat dissipation structure, comprising the following steps,

[0042] S1: using the same process as the side wall 21 to manufacture the top plate 22 with shielding effect;

[0043] S2: preparing the imprinting template;

[0044] S3: the imprinting template is used to manufacture the diffusion member 4 on the top surface of the top plate 22 by hot pressing.

[0045] Further, we found that although the design idea of patent number 202210635054.X can optimize the processing technology of the diffusion member 4 and reduce the processing difficulty, because of the existence of the heat conduction member 5, it is still not convenient to process the top surface of the top plate 22, therefore, we provide another embodiment to optimize the structure of the top plate 22 and the heat conduction member 5.

[0046] In this embodiment, two limiting tables 7 are symmetrically arranged in the opening of the side wall 21, and a first distance is reserved between the two limiting tables 7, the first distance is the distance between the two opposite surfaces of the two limiting tables 7, and the first distance is adapted to the size of the chip 3, as shown in Figure 11 When the side wall 21 is installed on the substrate, the four side surfaces of the chip are respectively attached to the two opposite surfaces of the two limiting tables 7 and the inner side surface of the side wall 21, as shown in Figure 9 and Figure 10 The heat conduction member 5 is arranged in the opening of the side wall 21, the heat conduction member 5 is sheet-shaped, and the bottom surface of the heat conduction member 5 is connected to the top surface of the limiting table 7, the top plate 22 is located in the opening of the side wall 21, and the shape of the top plate 22 is adapted to the shape of the opening of the side wall 21, so that the top plate 22 can be embedded in the opening of the side wall 21, the top plate 22 is pressed on the heat conduction member 5, and the bottom surface of the top plate 22 is connected to the top surface of the heat conduction member 5. Thus, the volume of the heat conduction member 5 can be greatly reduced compared with patent number 202210635054.X, so that the volume of the shielding cover 2 can be further optimized. The top plate 22 can be plate-shaped, which facilitates the preparation of the layered shielding structure of the top plate 22, and the diffusion member 4 is processed on the reflecting layer of the top plate 22, so that the mold for placing the top plate 22 is no longer needed.

[0047] Further, when preparing the multi-layer shielding structure, we tried to increase the micro-channel in the absorption layer and fill the magnetic nanofluid to improve the heat dissipation efficiency. However, the processing technology for making the micro-channel is complex, which will increase the cost of the multi-layer shielding structure, so it is abandoned. When designing the heat dissipation structure of the present application, the heat conduction piece 5 needs to be in full contact with the chip 3 to ensure the efficiency of heat transfer. Therefore, the contact surface of the heat conduction piece 5 and the chip 3 needs to have high flatness to reduce the gap between them. In order to optimize the processing requirements for the flatness of the surface of the heat conduction piece 5 and the chip 3, a through hole 51 is arranged on the heat conduction piece 5, the opening area of the through hole 51 is not greater than the surface area of the chip 3, the through hole 51 is filled with magnetic nanofluid, and the magnetic nanofluid is used to contact the top plate 22 and the chip 3 through the through hole 51, thereby improving the efficiency of heat transfer. The magnetic nanofluid can be Fe3O4@SiO2-perfluoropolyether. The top surface of the limiting table 7 is provided with a limiting groove 71, and the bottom surface of the heat conduction piece 5 is provided with a limiting piece 52. The heat conduction piece 5 is connected with the limiting table 7 through the cooperation between the limiting piece 52 and the limiting groove 71.

[0048] In the foregoing embodiment, by filling the magnetic nanofluid in the through hole 51, the gap between the heat conduction piece 5 and the chip 3 can be filled, and the key heating parts of the chip 3 can be covered, with less magnetic nanofluid. Further, as one of the many embodiments, a second distance is reserved between the bottom surface of the heat conduction piece 5 and the top surface of the chip 3, and the magnetic nanofluid is filled between the bottom surface of the heat conduction piece 5 and the top surface of the chip 3. In this embodiment, the magnetic nanofluid is used as the medium for heat conduction between the chip 3 and the heat conduction piece 5, which can reduce the aperture of the through hole 51, reduce the risk of leakage of the magnetic nanofluid out of the shielding cover 2, and has no requirement for the opening area of the side wall 21. The inner wall of the side wall 21 can have a gap with the chip 3. It should be noted that, because this embodiment uses the magnetic nanofluid "immersion type" heat transfer, there are certain requirements for the selection of the packaging material of the chip 3 and the magnetic nanofluid, for example, the magnetic nanofluid should be a chemically inert fluid (such as perfluoropolyether), and the packaging material of the chip 3 should be resistant to chemical corrosion (such as epoxy resin) to avoid chemical corrosion.

[0049] Further, while using the diffusion piece 4 to increase the heat dissipation area, a threaded groove is arranged in the opening of the side wall 21, the top surface of the top plate 22 is provided with an exchanger 8 which is in communication with a circulating device, the exchanger 8 is threadedly connected with the threaded groove, and the circulating device is connected with the exchanger 8 through a pipeline. Figure 8 and Figure 11The circulating device and the exchanger 8 can be commercial products or prior art. By adding the exchanger 8, the shield 2 can be actively cooled while being passively cooled by the diffuser 4, thereby improving the cooling efficiency.

[0050] In the description of the present application, it is to be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0051] In the present application, unless otherwise clearly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or detachably connected, or integrated; it can be mechanically connected, or electrically connected or communicable with each other; it can be directly connected, or indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise clearly specified and limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0052] Although the embodiments of the present application have been disclosed as above, it is not limited to the application listed in the specification and the embodiments, it can be fully applied to various fields suitable for the present application, and those skilled in the art can easily realize additional modifications, therefore the present application is not limited to specific details and the figures shown and described herein, without departing from the general concept defined by the claims and the equivalent scope.

Claims

1. A chip heat dissipation structure, comprising: A shielding cover (2) is disposed on a substrate (1). The shielding cover (2) consists of a sidewall (21) and a top plate (22). The sidewall (21) surrounds the outside of the chip (3) to form a frame structure. The bottom of the sidewall (21) is connected to the substrate (1). The top plate (22) closes the opening of the sidewall (21). The shielding cover (2) is characterized in that... Two limiting platforms (7) are symmetrically arranged inside the opening of the side wall (21). A first distance is reserved between the two limiting platforms (7), which is adapted to the size of the chip (3). A heat-conducting component (5) is arranged inside the opening of the side wall (21), and the bottom surface of the heat-conducting component (5) is connected to the top surface of the limiting platform (7). The top plate (22) is located inside the opening of the side wall (21), and the shape of the top plate (22) is adapted to the shape of the opening of the side wall (21). The bottom surface of the top plate (22) is connected to the top surface of the heat-conducting component (5).

2. The chip heat dissipation structure according to claim 1, characterized in that, The heat-conducting component (5) is provided with a through hole (51), the opening area of ​​the through hole (51) is not greater than the surface area of ​​the chip (3), and the through hole (51) is filled with magnetic nanofluid.

3. The chip heat dissipation structure according to claim 2, characterized in that, The top surface of the limiting platform (7) is provided with a limiting groove (71), and the bottom surface of the heat-conducting component (5) is provided with a limiting component (52). The heat-conducting component (5) is connected to the limiting platform (7) through the cooperation between the limiting component (52) and the limiting groove (71).

4. The chip heat dissipation structure according to claim 2, characterized in that, A second distance is reserved between the bottom surface of the heat-conducting component (5) and the top surface of the chip (3), and magnetic nanofluid is filled between the bottom surface of the heat-conducting component (5) and the top surface of the chip (3).

5. The chip heat dissipation structure according to any one of claims 1-4, characterized in that, The side wall (21) has a threaded groove in the opening, and the top surface of the top plate (22) has an exchanger (8) that communicates with the circulation device. The exchanger (8) is threadedly connected to the threaded groove.

Images