Power module heat dissipation structure and manufacturing method thereof

Abstract

The invention discloses a power module heat dissipation structure and a manufacturing method thereof, and belongs to the field of semiconductor devices. The method comprises the following steps: firstly, preparing fiber-reinforced phase change layers through a gradient calendering process, compounding a low-thermal-resistance interface material with a liquid cooling plate main body, compounding a uniform-temperature film with the low-thermal-resistance interface material by using film coating equipment, obtaining a uniform-temperature liquid cooling plate through a gradient hot pressing process, and then mounting the fiber-reinforced phase change layers on two sides of a chip. And alternately stacking the uniform-temperature liquid cooling plates and the chip layers to obtain a stacked structure (n is greater than or equal to 1, and n is an integer) with n layers of power chips and n + 1 layers of uniform-temperature liquid cooling plates, integrally pressurizing the device, installing a fastening structure, and finally installing and applying a liquid cooling pipeline. The heat dissipation structure prepared by the method has the characteristics of high space utilization rate and high heat dissipation efficiency. The method is simple to operate, high in production efficiency and suitable for industrial production.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor devices, specifically relating to a power module heat dissipation structure and its manufacturing method. Background Technology

[0002] The increasing integration of electronic devices has led to a significant increase in the volumetric power density or area power density of electronic components and devices. If internal heat cannot be effectively dissipated, the junction temperature of the components will rise sharply. When the maximum allowable junction temperature is exceeded, the performance of the components will degrade or even fail. Therefore, efficient heat dissipation technology is needed to ensure the stable operation of the equipment. High-power electronic components have traditionally used heat pipes, heat spreaders, and heat sinks for heat dissipation, usually mounted directly above the components. However, when there are multiple heat sources in the system, the heat dissipation modules become scattered, the number of system fans increases, the heat dissipation efficiency is low and the effect is poor, local hot spots are created, space is wasted, and the requirements of miniaturization and high efficiency of modern electronic devices cannot be met.

[0003] This invention designs a power module structure that integrates multiple high-power chips on both sides using liquid cooling, which improves heat dissipation efficiency and saves space compared to traditional single-sided heat dissipation structures. This invention introduces thermally conductive fibers into a thermally conductive phase change material with high latent heat of phase change through a unique process, improving the mechanical properties and temperature shock resistance of the thermally conductive phase change material, reducing its thermal resistance, and effectively mitigating phase change material leakage. This invention also uses a unique process to fabricate a low thermal resistance, temperature-uniform liquid-cooled plate, allowing heat to be quickly and evenly distributed and dissipated from the heating elements. The method provided by this invention also features simple processing, low cost, and suitability for industrial production. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and to achieve efficient heat dissipation of the chip by adopting a double-sided heat dissipation structure.

[0005] A method for manufacturing a heat dissipation structure for a power module, characterized in that the structure comprises: a first homogeneous liquid cooling plate... an nth homogeneous liquid cooling plate, an (n+1)th homogeneous liquid cooling plate, a fiber-reinforced phase change layer, a first power chip layer... an (n-1)th power chip layer, an nth power chip layer, a fastening structure, and liquid cooling pipes (n≥1, and n is an integer), and the manufacturing steps include: S01, Preparation of fiber-reinforced phase change layer: A pad-shaped thermally conductive phase change material is obtained by mechanical stirring, centrifugal degassing and calendering process. The thermally conductive fiber cloth is placed horizontally between the two pad-shaped thermally conductive phase change material sheets, and the fiber-reinforced phase change layer is obtained by gradient calendering process. S02, Preparation of a homogeneous liquid cooling plate: A low thermal resistance interface material is composited with a liquid cooling plate using a mounting process, screen printing process, or dispensing process. Then, a roll-to-roll lamination device is used to connect the homogeneous film and the low thermal resistance interface material. The resulting structure is placed in a press for gradient hot pressing. After holding the pressure for a period of time, a homogeneous liquid cooling plate is obtained. The material used before hot pressing is a low thermal resistance interface material. After hot pressing, the low thermal resistance interface material forms a low thermal resistance interface layer structure. The in-plane thermal conductivity of the film material used is greater than 200 W / (m·K), the thickness is less than 100 µm, and it contains one or more of the following: metal, silicon carbide, diamond, carbon nanotubes, graphene, graphite nanosheets, graphite, carbon fiber, and ceramic fiber. The thermal resistance of the low thermal resistance interface layer is less than 0.1 °C·cm. 2 / W (under 50Psi pressure), the low thermal resistance interface material is one or more of the following: thermally conductive gel, thermally conductive phase change material, thermally conductive grease, and thermally conductive pad. S03, First power chip layer installation: The fiber-reinforced phase change layer obtained in S01 is attached to both sides of the first power chip layer, and then the resulting structure is installed at the designed position on one side surface of the first homogeneous liquid cooling plate homogeneous film obtained in S02. S04, Second homogeneous liquid cooling plate installation: The second homogeneous liquid cooling plate prepared in S02 is installed on one side of the exposed fiber-reinforced phase change layer on the first power chip layer in the structure obtained in S03. S05, Layer-by-layer stacking: Repeat steps S03 and S04 to obtain a stacked structure with n layers of power chips and n+1 layers of homogeneous liquid cooling plates; S06, Fastening structure installation: Heat the structure obtained in S05 and apply pressure in a direction perpendicular to the chip surface, maintain for a period of time, mechanically fasten at the reserved position on the liquid cooling plate surface, and then release the pressure. S07, Flow channel connection: Connect the liquid cooling pipe to each layer of liquid cooling plate in the structure obtained in S06, and introduce coolant to start operation.

[0006] Furthermore, the gasket-shaped thermally conductive phase change material in step S01 has a thermal conductivity greater than 6 W / (m·K) and a thermal resistance less than 0.1 °C·cm. 2The thermally conductive fiber cloth in step S01 is made of thermally conductive fibers with a thermal conductivity greater than 20 W / (m·K) and a fiber diameter range of 6–20 μm. The thermally conductive fiber cloth has an insulation strength greater than 240–600 mesh and a thickness range of 20–40 μm. The thermally conductive fibers contain one or more of the following: carbon fiber, carbon nanotubes, graphene, alumina, boron nitride, silicon carbide, silver, copper, and aluminum. The thermally conductive fiber has an insulation strength greater than 20 kV / mm and a thickness range of 20–40 μm. The thermally conductive fiber contains one or more of the following: carbon fiber, carbon nanotubes, graphene, alumina, boron nitride, silicon carbide, silver, copper, and aluminum. The thermally conductive fiber has an insulation strength greater than 20 kV / mm and a thickness range of 20–40 μm. The thermally conductive fiber contains one or more of the following: carbon fiber, carbon nanotubes, graphene, alumina, boron nitride, silicon carbide, silver, copper, and aluminum.

[0007] Furthermore, the gradient calendering process in step S01 is characterized by being divided into two, three, or four stages. The calendering spacing in the first stage is 200–400 μm, the calendering spacing in the last stage is 60–140 μm, and the calendering spacing in the middle stage is located between the first and last stages and gradually decreases. The rolling temperature range for all stages is 70–120°C.

[0008] Further, the liquid cooling plate in step S02 comprises a first liquid cooling plate...an nth liquid cooling plate and an (n+1)th liquid cooling plate, wherein the first liquid cooling plate and the (n+1)th liquid cooling plate are both composited with a temperature-equalizing film on one side, and the liquid cooling plates between the first liquid cooling plate and the (n+1)th liquid cooling plate are both composited with a temperature-equalizing film on both sides, n≥1, and the liquid cooling plate is one or more of a blown liquid cooling plate, a stamped liquid cooling plate, and an assembled liquid cooling plate. The connection method between the inlet and outlet of the liquid cooling plate and the main body of the liquid cooling plate is one or more of welding, snap-fit ​​connection, sealing ring gasket, threaded connection, interference fit, and sealing glue. The preferred welding method is friction stir welding and brazing. The thermal conductivity of the material used for the main body of the liquid cooling plate is greater than 20W / (m·K), and it contains one or more of copper alloy, aluminum alloy, copper-based composite material, aluminum-based composite material, graphite, thermally conductive plastic, alumina ceramic, aluminum nitride ceramic, silicon nitride ceramic, zirconium oxide ceramic, and boron nitride ceramic, and its thickness ranges from 0.1mm to 50mm.

[0009] Furthermore, the gradient hot pressing process in step S02 is characterized by being divided into two stages. The hot pressing pressure in the first stage is 10~40Psi, and the hot pressing pressure in the second stage is greater than 50Psi. The temperature range of both stages is 70~120℃.

[0010] Furthermore, the power chip in steps S03, S04, and S05 is one or more of a field-effect transistor, an insulated-gate bipolar transistor, a transistor, a thyristor, and a diode, and the heat dissipation power of the chip is greater than 4W, with a side length of 0.5mm to 50mm.

[0011] Furthermore, the characteristic is that the final temperature of the heating in step S06 depends on the melting point of the phase change material and the maximum temperature resistance of the chip, and the temperature range is 60~140℃. The pressure of step S06 is 10~110Psi, and the pressure time is 1~20min.

[0012] Furthermore, the fastening structure in step S07 is characterized by being made of one or more of metal, resin, ceramic fiber, and composite materials, with a tensile strength greater than 100 MPa and a temperature resistance greater than 150°C.

[0013] A power module heat dissipation structure is characterized in that the heat dissipation structure is prepared by any of the methods described above, and can meet the heat dissipation requirements of a total chip heat dissipation power greater than 60W, and has the function of simultaneously performing double-sided liquid cooling heat dissipation on a multi-layer chip stacked structure. Compared with the prior art, the advantages of the present invention are: (1) The heat dissipation structure prepared by this method can stack multi-layer chips and perform double-sided liquid cooling at the same time, which has the advantages of high space utilization and high heat dissipation efficiency. (2) The heat dissipation structure prepared by this method introduces thermally conductive fiber cloth into the thermally conductive phase change material through a unique gradient calendering process, which improves the thermal conductivity and mechanical properties of the thermally conductive phase change material and effectively reduces the thickness of the phase change material and prevents leakage of the phase change material. (3) The heat dissipation structure prepared by this method combines the liquid cooling plate and the temperature homogenizing film through industrial equipment and a unique gradient hot pressing process. While introducing the temperature homogenizing film on the surface of the liquid cooling plate, the interfacial thermal resistance between the two is reduced. The prepared temperature homogenizing liquid cooling plate has good temperature homogenization effect and high heat dissipation efficiency. Attached Figure Description

[0014] Appendix Figure 1 This is a flowchart of the overall manufacturing process of the present invention.

[0015] Appendix Figure 2 This is a three-dimensional structural diagram of the present invention.

[0016] Appendix Figure 3 This is a side view of the present invention, with a partial enlarged view in the lower left corner.

[0017] Appendix Figure 4 This is a schematic diagram showing the chip numbers of the first and second chip layers in this embodiment.

[0018] Appendix Figure 5This is a schematic diagram showing the chip numbers of the first chip layer in the comparative model.

[0019] Appendix Figure 6 The graphs show the temperature changes over time for the chips with the highest and lowest junction temperatures in the first chip layer of the embodiments and comparative examples. Detailed Implementation

[0020] In the following description, only certain exemplary embodiments are depicted simply. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0021] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0022] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0023] The following disclosure provides many different embodiments or examples for implementing the invention. To simplify the disclosure, specific examples are described below. Of course, these are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0024] Example

[0025] The embodiments specifically illustrate the application of a manufacturing method for a power module heat dissipation structure in MOSFET chip heat dissipation.

[0026] When n=2, the heat dissipation structure has 2 layers of power chips and 3 layers of vapor chamber liquid cooling plates, such as Figure 2 and Figure 3 As shown, the power module heat dissipation structure mainly includes the following parts: liquid cooling plate 101, low thermal resistance interface layer 102, temperature homogenizing film 103, fiber reinforced phase change layer 104, first power chip layer 105, second power chip layer 106, liquid cooling pipe 107, and fastening structure 108; the liquid cooling plate 101, low thermal resistance interface layer 102, and temperature homogenizing film 103 together constitute a temperature homogenizing liquid cooling plate, which, from bottom to top, are the first temperature homogenizing liquid cooling plate, the second temperature homogenizing liquid cooling plate, and the third temperature homogenizing liquid cooling plate.

[0027] S01, Preparation of fiber-reinforced phase change layer: Silver-coated copper powder, diamond powder, phase change material, and other components are mixed through mechanical stirring, centrifugal degassing, and calendering processes to obtain a pad-shaped thermally conductive phase change material. The resulting pad-shaped thermally conductive phase change material has a thermal conductivity of 14 W / (m·K) and a thermal resistance of 0.06℃·cm. 2 The structure features a thickness of 180µm and an insulation strength of 2.4kV / mm. The silver-coated copper powder has a particle size distribution of 1~12μm and a D50 of 7μm. The diamond powder has a particle size distribution of 0.01~2μm and a D50 of 1μm. The phase change material is high-purity paraffin wax with a latent heat of phase change of 256J / g. A thermally conductive fiber cloth is horizontally placed between two sheets of pad-shaped thermally conductive phase change material, and fiber-reinforced phase change material is obtained through a gradient calendering process. Layer 104, the thermally conductive fiber used in the thermally conductive fiber cloth is silver wire with a purity of 99.9% and a thermal conductivity greater than 400W / (m·K). The fiber diameter is 10µm. The fiber web has a mesh count of 200 mesh and a thickness of 20µm. The calendering process is divided into two stages. In the first stage of calendering, the roller spacing before calendering is 220μm and the heating temperature is 80℃. In the second stage of calendering, the roller spacing before calendering is 70μm and the heating temperature is 80℃. The calender is a twin-roll calender. S02, Preparation of the homogeneous liquid cooling plate: A low thermal resistance interface material is composited with the liquid cooling plate 101 using a screen printing process. Then, a roll-to-roll lamination device is used to connect the homogeneous film to the low thermal resistance interface material. Finally, the resulting structure is placed in a press for gradient hot pressing. After standing for a period of time, the homogeneous liquid cooling plate is obtained. The material used before hot pressing is a low thermal resistance interface material. After hot pressing, the low thermal resistance interface material forms a low thermal resistance interface layer 102. The low thermal resistance interface material is the thermally conductive phase change material prepared in step S01. The thermal resistance of the low thermal resistance interface layer 102 is 0.06℃·cm. 2 / W (at 50Psi pressure), the homogeneous film 103 is a pyrolytic graphite film with a transverse thermal conductivity of 1200W / (m·K) and a thickness of 50µm. At this time, n=2. The first and third homogeneous liquid cooling plates are both composite graphite films on one side, and the second homogeneous liquid cooling plate is composite graphite films on both sides. The liquid cooling plates used are assembled liquid cooling plates. The inlet and outlet are connected to the main body of the liquid cooling plate by snaps and sealed with sealing rings. The material used for the liquid cooling plate is 3003 aluminum alloy with a thermal conductivity of 193W / (m·K) and a thickness of 30mm. The gradient hot pressing process is divided into two stages. The hot pressing pressure of the first stage is 30Psi and the hot pressing temperature is 90℃. The hot pressing pressure of the second stage is 80Psi and the hot pressing temperature is 90℃. S03, First power chip layer installation: The fiber-reinforced phase change layer 104 obtained in S01 is attached to the first power chip layer 105 on both sides, and then the resulting structure is installed on the designed position on one side surface of the first homogeneous liquid cooling plate homogeneous film 103 obtained in S02. The first power chip layer 105 is a MOSFET power chip, and the average heat dissipation power of each chip is 28W, and the size is 20×28mm. S04, Second heat-equalizing liquid cooling plate installation: The second heat-equalizing liquid cooling plate obtained in S02 is installed on the exposed fiber-reinforced phase change layer 104 side of the first power chip layer 105 in the structure obtained in S03. The second power chip layer 106 is a MOSFET power chip with an average heat dissipation power of 28W and a size of 20×28mm. There are 6 chips per layer. S05, stack layer by layer; repeat steps S03 and S04 to obtain a stacked structure of chip layers and liquid cooling plates with 2 power chip layers and 3 homogeneous liquid cooling plates. S06, Fastening structure installation: The structure obtained in S05 is heated and pressurized in a direction perpendicular to the chip surface. After holding for a period of time, the pressure is released after mechanical fastening at the reserved position on the liquid cooling plate surface. The heating temperature is 90℃, the pressurization pressure is 40Psi, and the pressurization time is 3min. The fastening structure 108 is fastened with bolts and nuts, with a tensile strength of 110MPa and a temperature resistance of 160℃. S07, Flow channel connection: Connect the external liquid cooling pipe 107 to each layer of liquid cooling plate in the structure obtained in S06, and introduce coolant to start operation.

[0028] Comparative Example Using a liquid cooling plate without composite temperature-equalizing film, a single-layer chip is connected to and dissipates heat from the single-layer liquid cooling plate (first liquid cooling plate) via a commercial thermal pad with a strength of 4 W / (m·K).

[0029] S01, First power chip layer installation: A commercial thermal pad with a thermal conductivity of 4 W / (m·K) is mounted on one side of the first power chip layer 105. The resulting structure is then installed on the designed position on the surface of the first liquid cooling plate. The thermal pad is connected to the main body of the liquid cooling plate. The first power chip layer 105 is a MOSFET power chip with an average heat dissipation power of 28W and a size of 20×28mm. The liquid cooling plate used is an assembled liquid cooling plate. The inlet and outlet are connected to the main body of the liquid cooling plate by snap-fit ​​and sealed with a sealing ring. The material used for the liquid cooling plate is 3003 aluminum alloy with a thermal conductivity of 193 W / (m·K) and a thickness of 30mm. S02, Fastening structure installation: The structure obtained in S01 is heated and pressure is applied in a direction perpendicular to the chip surface. After holding for a period of time, the pressure is released after mechanical fastening at the reserved position on the liquid cooling plate surface. The heating temperature is 90℃, the pressure is 40Psi, and the pressure time is 3min. The fastening structure 108 is fastened with bolts and nuts, with a tensile strength of 110MPa and a temperature resistance of 160℃. S03, Flow channel connection: Connect the external liquid cooling pipe 107 to the liquid cooling plate in the structure obtained in S02, and introduce coolant to start operation.

[0030] Table 1. Key parameters and test results in the examples and comparative examples.

[0031] The above embodiments and comparative examples were tested, and the test parameters and results are shown in Table 1. When the average heat dissipation of the chip was 28W, the same type of liquid cooling plate was used for liquid cooling, and the coolant flow rate was 1m / s. The chip numbers in the first power chip layer and the second power chip layer in the embodiments are as follows: Figure 4 As shown, the chip numbers in the first power chip layer of the comparative example are as follows: Figure 5 As shown in the figure. In the power module heat dissipation structure manufactured in this embodiment, the junction temperature of each chip in the first chip layer is reduced by an average of 21.0℃ compared to the comparative example. The temperature change curves over time for the chips with the highest and lowest junction temperatures in the first chip layer of the embodiment and the comparative example are shown in the figure. Figure 6 As shown.

[0032] A comparative analysis of the embodiments and comparative examples reveals the following: In the comparative example, the heat generated by the first power chip layer 105 is only longitudinally transferred to the first liquid cooling plate body through a commercially available thermally conductive pad with a strength of 4 W / (m·K) and is carried away by the coolant in a localized area. In the embodiment, the heat generated by the first power chip layer 105 is longitudinally transferred to the first and second homogeneous liquid cooling plates through a low thermal resistance fiber-reinforced phase change layer and is rapidly evenly distributed by the homogeneous film, ultimately being carried away by the coolant from both liquid cooling plates. Furthermore, the embodiment can simultaneously perform double-sided liquid cooling for the multi-layer chip stacked structure. Clearly, the embodiment has more heat dissipation paths than the comparative example, resulting in better heat dissipation capabilities. In summary, the manufacturing method provided by this invention can be used to prepare a heat dissipation structure with high-efficiency heat dissipation capabilities.

[0033] Although the invention has been described with reference to exemplary embodiments, it should be understood that the terminology used is descriptive and exemplary, and not restrictive. Since the invention can be embodied in many forms without departing from the spirit or essence of the invention, it should be understood that the above embodiments are not limited to any of the foregoing details, but should be interpreted broadly within the spirit and scope defined by the appended claims. Therefore, all variations and modifications falling within the scope of the claims or their equivalents should be covered by the appended claims.

Claims

1. A method for manufacturing a heat dissipation structure for a power module, characterized in that, Its structure includes: a first homogenized liquid cooling plate... an nth homogenized liquid cooling plate, an (n+1)th homogenized liquid cooling plate, a fiber-reinforced phase change layer, a first power chip layer... an (n-1)th power chip layer, an nth power chip layer, a fastening structure, and liquid cooling pipes (n≥1, and n is an integer). Its manufacturing steps include: S01, Preparation of fiber-reinforced phase change layer: A pad-shaped thermally conductive phase change material is obtained by mechanical stirring, centrifugal degassing and calendering process. The thermally conductive fiber cloth is placed horizontally between the two pad-shaped thermally conductive phase change material sheets, and the fiber-reinforced phase change layer is obtained by gradient calendering process. S02, Preparation of a homogeneous liquid cooling plate: A low thermal resistance interface material is composited with a liquid cooling plate using a mounting process, screen printing process, or dispensing process. Then, a roll-to-roll lamination device is used to connect the homogeneous film and the low thermal resistance interface material. The resulting structure is placed in a press for gradient hot pressing. After holding the pressure for a period of time, a homogeneous liquid cooling plate is obtained. The material used before hot pressing is a low thermal resistance interface material. After hot pressing, the low thermal resistance interface material forms a low thermal resistance interface layer structure. The in-plane thermal conductivity of the film material used is greater than 200 W / (m·K), the thickness is less than 100 µm, and it contains one or more of the following: metal, silicon carbide, diamond, carbon nanotubes, graphene, graphite nanosheets, graphite, carbon fiber, and ceramic fiber. The thermal resistance of the low thermal resistance interface layer is less than 0.1 °C·cm. 2 / W (under 50Psi pressure), the low thermal resistance interface material is one or more of the following: thermally conductive gel, thermally conductive phase change material, thermally conductive grease, and thermally conductive pad. S03, First power chip layer installation: The fiber-reinforced phase change layer obtained in S01 is attached to both sides of the first power chip layer, and then the resulting structure is installed at the designed position on one side surface of the first homogeneous liquid cooling plate homogeneous film obtained in S02. S04, Second homogeneous liquid cooling plate installation: The second homogeneous liquid cooling plate prepared in S02 is installed on one side of the exposed fiber-reinforced phase change layer on the first power chip layer in the structure obtained in S03. S05, Layer-by-layer stacking: Repeat steps S03 and S04 to obtain a stacked structure with n layers of power chips and n+1 layers of homogeneous liquid cooling plates; S06, Fastening structure installation: Heat the structure obtained in S05 and apply pressure in a direction perpendicular to the chip surface, maintain for a period of time, mechanically fasten at the reserved position on the liquid cooling plate surface, and then release the pressure. S07, Flow channel connection: Connect the liquid cooling pipe to each layer of liquid cooling plate in the structure obtained in S06, and introduce coolant to start operation.

2. The manufacturing method according to claim 1, characterized in that, The gasket-shaped thermally conductive phase change material in step S01 has a thermal conductivity greater than 6 W / (m·K) and a thermal resistance less than 0.1 °C·cm. 2 The thermally conductive fiber cloth in step S01 is made of thermally conductive fibers with a thermal conductivity greater than 20 W / (m·K) and a fiber diameter range of 6–20 μm. The thermally conductive fiber cloth has an insulation strength greater than 240–600 mesh and a thickness range of 20–40 μm. The thermally conductive fibers contain one or more of the following: carbon fiber, carbon nanotubes, graphene, alumina, boron nitride, silicon carbide, silver, copper, and aluminum. The thermally conductive fiber has an insulation strength greater than 20 kV / mm and a thickness range of 20–40 μm. The thermally conductive fiber contains one or more of the following: carbon fiber, carbon nanotubes, graphene, alumina, boron nitride, silicon carbide, silver, copper, and aluminum. The thermally conductive fiber has an insulation strength greater than 20 kV / mm and a thickness range of 20–40 μm. The thermally conductive fiber contains one or more of the following: carbon fiber, carbon nanotubes, graphene, alumina, boron nitride, silicon carbide, silver, copper, and aluminum.

3. The manufacturing method according to claim 1, characterized in that, The gradient calendering process in step S01 is divided into two, three, or four stages. The calendering spacing in the first stage is 200–400 μm, the calendering spacing in the last stage is 60–140 μm, and the calendering spacing in the middle stage is between the first and last stages and gradually decreases. The rolling temperature range for all stages is 70–120°C.

4. The manufacturing method according to claim 1, characterized in that, The liquid cooling plate in step S02 includes a first liquid cooling plate, ... an nth liquid cooling plate, and an (n+1)th liquid cooling plate. The first liquid cooling plate and the (n+1)th liquid cooling plate are both composited with a temperature-equalizing film on one side, and the liquid cooling plates between the first liquid cooling plate and the (n+1)th liquid cooling plate are both composited with a temperature-equalizing film on both sides, where n ≥ 1. The liquid cooling plate is one or more of the following: blown liquid cooling plate, stamped liquid cooling plate, and assembled liquid cooling plate. The connection method between the inlet and outlet of the liquid cooling plate and the main body of the liquid cooling plate is one or more of the following: welding, snap-fit ​​connection, gasket sealing ring, threaded connection, interference fit, and sealant filling. The preferred welding method is friction stir welding or brazing. The thermal conductivity of the material used for the main body of the liquid cooling plate is greater than 20 W / (m·K), and it contains one or more of the following: copper alloy, aluminum alloy, copper-based composite material, aluminum-based composite material, graphite, thermally conductive plastic, alumina ceramic, aluminum nitride ceramic, silicon nitride ceramic, zirconium oxide ceramic, and boron nitride ceramic, with a thickness ranging from 0.1 mm to 50 mm.

5. The manufacturing method according to claim 1, characterized in that, The gradient hot pressing process in step S02 is divided into two stages. The hot pressing pressure in the first stage is 10~40Psi, and the hot pressing pressure in the second stage is greater than 50Psi. The temperature range of both stages is 70~120℃.

6. The manufacturing method according to claim 1, characterized in that, The power chip in steps S03, S04, and S05 is one or more of the following: field-effect transistor, insulated-gate bipolar transistor, transistor, thyristor, and diode. The heat dissipation power of the chip is greater than 4W, and the side length is 0.5mm to 50mm.

7. The manufacturing method according to claim 1, characterized in that, The final temperature of step S06 depends on the melting point of the phase change material and the maximum temperature resistance of the chip, and the temperature range is 60~140℃. The pressure of step S06 is 10~110Psi, and the pressurization time is 1~20min.

8. The manufacturing method according to claim 1, characterized in that, The fastening structure in step S07 is made of one or more of metal, resin, ceramic fiber, and composite materials, with a tensile strength greater than 100 MPa and a temperature resistance greater than 150°C.

9. A heat dissipation structure for a power module, characterized in that, The heat dissipation structure is prepared by the method of any one of claims 1 to 8, and can meet the heat dissipation requirements of a total chip heat dissipation power greater than 60W, and has the function of simultaneously performing double-sided liquid cooling heat dissipation on a multi-layer chip stack structure.

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