Plastic package power module assembly and manufacturing method thereof

Abstract

The invention discloses a plastic package power module assembly and a manufacturing method thereof, and relates to the technical field of power modules.The plastic package power module assembly comprises a shell, a power device and a main control panel, a plurality of heat dissipation grooves are formed in the shell, the heat dissipation grooves are communicated with an external water path through heat dissipation water channels, and the power device is connected with the main control panel; the power device is provided with an installation surface and a heat dissipation surface which are oppositely arranged, the heat dissipation surface is arranged towards the heat dissipation groove, a chip is installed on the installation surface, the installation surface is provided with pins extending back to the heat dissipation groove, the heat dissipation surface is provided with a plurality of heat dissipation pieces, at least part of the structure of each heat dissipation piece is located in the heat dissipation groove, and the main control board is arranged in the shell. The power device is electrically connected with the main control board through a pin; according to the technical scheme provided by the invention, a conventional copper substrate is canceled, and the power device provided with the chip is cooled by direct water cooling, so that the heat dissipation effect is prevented from being influenced due to certain thermal resistance in the presence of the copper substrate and the solder.

Description

Technical Field

[0001] The present invention relates to the technical field of power modules, and in particular to a plastic-encapsulated power module component and a manufacturing method thereof. Background Art

[0002] With the rapid development of electric drive technology for new energy vehicles, electric drive systems tend to be more powerful and smaller in size, and motor controllers need to be highly integrated and miniaturized. At the same time, in order to meet the needs of different powers, modular and platform products need to be launched to shorten the development cycle and reduce development costs.

[0003] The power module component in the motor controller is the core part of the controller, which is responsible for converting the input DC or AC power into the current and voltage required by the motor to drive the operation of the motor. It is usually composed of multiple power semiconductor devices (such as insulated gate bipolar transistors IGBT or metal oxide semiconductor field effect transistors MOSFET), which adjust the motor speed, torque and direction through precise switching control. The power module needs to have high efficiency, high reliability and good heat dissipation performance to meet the needs of the motor under different working conditions. It is widely used in electric vehicles, industrial robots, wind power generation and other fields. It is a key component for achieving precise motor control and efficient energy conversion.

[0004] The main reason why power modules generate serious heat is that the power electronic devices inside them generate a lot of heat during high-frequency switching, which causes the module temperature to rise. If the heat dissipation measures are not appropriate, the heat cannot be dissipated in time, which will cause the module temperature to be too high, affecting its performance and life. Therefore, copper substrates with pins are usually used to achieve cooling through coolant, but due to the presence of copper substrates and solder, there is still a certain thermal resistance and complex process, which affects the heat dissipation performance. Summary of the invention

[0005] The main purpose of the present invention is to provide a plastic-encapsulated power module assembly and a manufacturing method thereof, aiming to improve the heat dissipation structure of the power module, thereby optimizing its heat dissipation performance.

[0006] To achieve the above-mentioned purpose, the present invention provides a plastic-encapsulated power module assembly, which comprises:

[0007] A shell body, wherein the shell body is formed with a plurality of heat dissipation slots, and the plurality of heat dissipation slots are connected with an external water channel through a heat dissipation water channel;

[0008] A power device, the power device having a mounting surface and a heat dissipation surface arranged opposite to each other, the heat dissipation surface being arranged toward the heat dissipation slot, a chip being mounted on the mounting surface, the mounting surface being provided with pins extending away from the heat dissipation slot, the heat dissipation surface being provided with a plurality of heat dissipating elements, at least a portion of the structure of each of the heat dissipating elements being located in the heat dissipation slot; and

[0009] A main control board is arranged on the shell, and the power device is electrically connected to the main control board through the pins.

[0010] In one embodiment, the power device includes a composite substrate, the composite substrate is disposed on the heat dissipation surface, and a plurality of heat dissipating elements are bonded to the composite substrate.

[0011] In one embodiment, the composite substrate includes a first metal layer, a ceramic layer, and a second metal layer stacked in sequence from one end close to the heat sink to an end away from the heat sink, and a plurality of the heat sinks are bonded to the first metal layer.

[0012] In one embodiment, the material of the first metal layer and / or the second metal layer is oxygen-free copper; and / or

[0013] The material of the ceramic layer is silicon nitride.

[0014] In one embodiment, the heat sink is a strip-shaped heat dissipation structure, which includes two connecting parts and a bending part. The two connecting parts are respectively arranged at two ends of the bending part, and the two connecting parts are arranged on the heat dissipation surface. The bending part is bent toward the heat dissipation groove.

[0015] In one embodiment, the heat sink is a columnar heat sink structure and extends toward the heat sink.

[0016] In one embodiment, a notch of each heat dissipation slot is provided with an annular seal, and the annular seal is respectively in contact with the housing and the power device.

[0017] In one embodiment, the plastic-encapsulated power module assembly further includes a pressing block, the pressing block is provided with a limiting groove toward the power device, and a partial structure of the power device abuts against the limiting groove for limiting.

[0018] In one embodiment, connecting plates are respectively provided on both sides of the power device, one of the connecting plates is electrically connected to the capacitor copper busbar, and the other connecting plate is electrically connected to the three-phase copper busbar.

[0019] The present invention also provides a method for manufacturing a plastic-encapsulated power module assembly, which is applied to the manufacture of a composite substrate in the above-mentioned plastic-encapsulated power module assembly, and comprises the following steps:

[0020] Obtaining copper material and forming a first copper sheet and a second copper sheet having different thicknesses;

[0021] Printing silver paste on the first copper sheet and the second copper sheet;

[0022] welding the first copper sheet and the second copper sheet;

[0023] A plurality of heat dissipation elements are etched on a side of the first copper sheet facing away from the second copper sheet.

[0024] The technical solution of the present invention proposes a plastic-encapsulated power module component and a manufacturing method thereof, wherein the plastic-encapsulated power module component includes a shell, a power device and a main control board, the shell is formed with a plurality of heat dissipation grooves, the plurality of heat dissipation grooves are connected with an external water channel through a heat dissipation water channel, the power device has a mounting surface and a heat dissipation surface arranged relatively, the mounting surface is provided with a control chip, and the heat dissipation surface is provided with a plurality of heat dissipating parts, at least part of the structure of each heat dissipating part is located in the heat dissipation groove and contacts the coolant in the heat dissipation groove, the main control board is arranged in the shell and is electrically connected to the power device, in this technical solution, the conventional copper substrate is eliminated, and direct water cooling is adopted to cool the power device with the chip installed, thereby avoiding the existence of a certain thermal resistance due to the presence of the copper substrate and solder, which affects the heat dissipation effect.

[0025] Moreover, by optimizing the design and manufacturing methods of key power devices, the manufacturing process is simplified and the convenience of installation and maintenance is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0027] Figure 1 A schematic diagram of the exploded structure of an embodiment of a plastic-encapsulated power module assembly provided by the present invention;

[0028] Figure 2 for Figure 1 Schematic diagram of the exploded structure of the plastic-encapsulated power module assembly from another angle;

[0029] Figure 3 for Figure 2 A partial enlarged view of the middle A;

[0030] Figure 4 A structural schematic diagram of an embodiment of a plastic-encapsulated power module assembly provided by the present invention;

[0031] Figure 5 It is a schematic diagram of the structure of the composite substrate in the plastic-encapsulated power module assembly;

[0032] Figure 6 A schematic structural diagram of a first embodiment of a heat sink provided by the present invention;

[0033] Figure 7A schematic structural diagram of a second embodiment of a heat sink provided by the present invention;

[0034] Figure 8 A schematic structural diagram of a third embodiment of the heat sink provided by the present invention;

[0035] Fig. 9 for Figure 8 A partial enlarged view of the heat sink.

[0036] Description of Figure Numbers:

[0037] 100. Plastic-encapsulated power module assembly; 1. Shell; 11. Heat sink; 12. Heat dissipation channel; 2. Power device; 21. Mounting surface; 22. Heat dissipation surface; 23. Composite substrate; 231. First metal layer; 232. Ceramic layer; 233. Second metal layer; 24. Heat sink; 241. Strip heat dissipation structure; 241a. Connecting part; 241b. Bending part; 242. Columnar heat dissipation structure; 243. Mesh heat dissipation structure; 243a. Water hole; 25. Pin; 26. Connecting piece; 3. Main control board; 4. Press block; 41. Press block bolt; 42. Limiting groove; 5. Capacitor copper busbar; 51. Capacitor copper busbar bolt; 6. Three-phase copper busbar; 61. Three-phase copper busbar bolt; 7. Ring seal.

[0038] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0041] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0042] The present invention proposes a plastic-encapsulated power module assembly and a manufacturing method thereof, aiming to improve the heat dissipation structure of the power module, thereby optimizing its heat dissipation performance. Figures 1 to 9 A schematic structural diagram of an embodiment of a plastic-encapsulated power module assembly provided by the present invention.

[0043] Please refer to Figures 1 to 9 The present invention proposes a plastic-encapsulated power module assembly 100, including a shell 1, a power device 2 and a main control board 3. The shell 1 is formed with a plurality of heat dissipation slots 11, and the plurality of heat dissipation slots 11 are connected with an external water channel through a heat dissipation water channel 12. The power device 2 has a mounting surface 21 and a heat dissipation surface 22 that are relatively arranged. The heat dissipation surface 22 is arranged toward the heat dissipation slot 11. A chip is mounted on the mounting surface 21. The mounting surface 21 is provided with pins 25 extending back to the heat dissipation slot 11. The heat dissipation surface 22 is provided with a plurality of heat dissipating elements 24. At least part of the structure of each heat dissipating element 24 is located in the heat dissipation slot 11. The main control board 3 is arranged in the shell 1, and the power device 2 is electrically connected to the main control board 3 through the pins 25.

[0044] Since the copper substrate in the traditional power module often has a certain resistance, resulting in low heat dissipation efficiency, in view of this, in the technical solution of the present invention, the copper substrate structure is abandoned to achieve direct water cooling. The technical solution adopts a plastic-encapsulated power single tube with dual IGBTs in parallel or a plastic-encapsulated power half-bridge with multiple chips in parallel, and directly sets a heat sink 24 in contact with cooling water under the power device 2, so that the heat generated by the power device 2 is directly transferred to the cooling water, avoiding the thermal resistance caused by the presence of the copper substrate and improving the heat dissipation performance.

[0045] The technical solution of the present invention proposes a plastic-encapsulated power module assembly 100 and a manufacturing method thereof, wherein the plastic-encapsulated power module assembly 100 includes a shell 1, a power device 2 and a main control board 3, the shell 1 is formed with a plurality of heat dissipation grooves 11, and the plurality of heat dissipation grooves 11 are connected with an external water channel through a heat dissipation water channel 12, the power device 2 has a mounting surface 21 and a heat dissipation surface 22 arranged oppositely, the mounting surface 21 is provided with a control chip, and the heat dissipation surface 22 is provided with a plurality of heat dissipating elements 24, at least part of the structure of each heat dissipating element 24 is located in the heat dissipation groove 11 and contacts the coolant in the heat dissipation groove 11, the main control board 3 is arranged in the shell 1 and is electrically connected to the power device 2, in the present technical solution, the conventional copper substrate is cancelled, and direct water cooling is adopted to cool the power device 2 with the chip installed, thereby avoiding the existence of a certain thermal resistance due to the presence of the copper substrate and solder, which affects the heat dissipation effect.

[0046] Moreover, by optimizing the design and manufacturing method of the key power device 2, its manufacturing process is simplified and the convenience of installation and maintenance is improved.

[0047] It should be noted that the heat dissipation slots 11 on the housing 1 can be connected to each other or independent of each other, and the present invention does not limit this. In one embodiment of the present invention, the housing 1 is provided with three heat dissipation slots 11 in total, and the three heat dissipation slots 11 are connected to each other. A heat dissipation water channel 12 for passing water is arranged inside the housing 1. The heat dissipation water channel 12 connects the three heat dissipation slots 11 and is led out from one side of the housing 1 to communicate with the external coolant water supply water channel. The coolant enters each heat dissipation slot 11 from the heat dissipation water channel 12 and contacts with the multiple heat dissipating elements 24 in the heat dissipation slot 11 to exchange heat. After absorbing the heat emitted from the heat dissipating elements 24, the coolant flows out of the housing 1 through the heat dissipation water channel 12 to form a cooling cycle. The circulating cooling water system can improve the heat transfer efficiency of the equipment and reduce the operating temperature of the equipment, thereby ensuring that the power device 2 is at the most suitable operating temperature.

[0048] Furthermore, the coolant may be cooling water or other cooling liquids with a higher specific heat capacity, which is not limited in the present invention. In one embodiment of the present invention, the coolant of the power device 2 is cooling water. Water has a higher specific heat capacity and thermal conductivity, and can effectively absorb and transfer heat, thereby quickly reducing the temperature of the power device 2. In addition, a water cooling system generally has lower energy consumption and noise levels because a large number of fans are not required. The maintenance of the water cooling system is relatively simple and the cost is low.

[0049] Since the bottom of the power device 2 in this case is in direct contact with the cooling water, in order to prevent the cooling water from causing a short circuit and structural corrosion of the power device 2, a composite substrate 23 is provided on the heat dissipation surface 22 of the power device 2. For details, please refer to Figure 1 and Figure 5The composite substrate 23 is made of a plurality of materials, and the plurality of materials include metal heat dissipation materials with good heat dissipation effect and insulating materials with good insulation performance. Specifically, the composite substrate 23 includes a first metal layer 231, a ceramic layer 232 and a second metal layer 233 which are stacked in sequence from one end close to the heat sink 24 to the end away from the heat sink 24. A plurality of heat sinks 24 are installed on the first metal layer 231 by a bonding process. The bonding process is mainly used to closely combine different materials or components to achieve the required functions and performances. The bonding process can not only achieve close bonding of materials, but also ensure the airtightness and long-term stability of the bonding interface, thereby improving the performance and reliability of the device, thereby improving the structural reliability of the heat sink 24 and the composite substrate 23.

[0050] In one embodiment of the present invention, the first metal layer 231 and the second metal layer 233 are both made of oxygen-free copper. Oxygen-free copper has extremely high thermal conductivity and can effectively transfer heat from the heat source to the coolant, thereby quickly reducing the temperature of the device. Secondly, the high purity and low oxygen content of oxygen-free copper make it have good corrosion resistance and can maintain stable performance in various harsh environments. In addition, oxygen-free copper also has good mechanical properties and ductility, which is easy to process into various complex shapes to meet different cooling needs. Further, in order to prevent the first metal layer 231 disposed toward the heat sink 11 from rusting on its surface due to long-term contact with the coolant, the surface of the first metal layer 231 is provided with an electroplating layer, and the material of the electroplating layer is not limited by the present invention. In one embodiment of the present invention, the electroplating layer is a nickel-plating layer, which has excellent corrosion resistance and can form a dense protective layer in the coolant environment, effectively preventing the metal layer from rusting due to contact with the coolant. Secondly, the hardness of the nickel-plating layer is high, which can improve the wear resistance and mechanical strength of the cooling plate and extend its service life. In addition, the nickel plating layer has good adhesion and uniformity, which can ensure the stability and reliability of the coating.

[0051] In the manufacturing process of the composite substrate 23, if the difference in thickness between the first metal layer 231 and the second metal layer 233 exceeds 0.2mm, the intermediate ceramic sheet will be greatly warped during the cooling process of the welding of the two metal layers, and even worse, the ceramic sheet will be broken. In view of this, in order to avoid the breakage of the intermediate ceramic layer 232, the second metal layer 233 adopts a copper layer with a thickness of 0.8mm to provide sufficient cross-sectional area for flow and a small etching insulation distance, and the first metal layer 231 adopts a copper layer with a thickness of 2mm, and is etched to ensure that the weight deviation of the copper layer on the front and back is within 20%. In this embodiment, the second metal layer 233 weighs 22.25g, the first metal layer 231 substrate thickness is 2mm, and a 1.5mm heat dissipation pin column is formed by etching, and a 0.5mm support layer is retained, which weighs 17.9g and has a deviation of 19.55%, thereby ensuring better structural stability.

[0052] It is understandable that the present invention does not limit the specific shape, quantity and location of the heat sink 24. In the first embodiment of the heat sink 24 proposed by the present invention, the heat sink 24 is a strip heat sink structure 241. For details, please refer to Figure 6 The strip heat dissipation structure 241 includes two connecting parts 241a and a bending part 241b. The two connecting parts 241a are respectively arranged at the two ends of the bending part 241b. The two connecting parts 241a are arranged on the heat dissipation surface 22. The bending part 241b is bent toward the heat dissipation groove 11. It can be bent in an arc shape or in a straight section. The present application does not limit this. In this embodiment, the bending part 241b is bent in an arc shape as a whole, and the two connecting parts 241a and the bending part 241b are an integrated structure. The strip heat dissipation structure 241 is made of aluminum. Aluminum has good thermal conductivity. Its thermal conductivity is about 238W / (m·K), which is second only to copper. It can effectively conduct heat away quickly and maintain the stable operating temperature of the equipment. Secondly, aluminum is light and its density is only one-third of that of copper, which can effectively realize the lightweight of the power module. In addition, aluminum has good corrosion resistance. After anodizing, a protective film will be formed on the surface, which can effectively resist oxidation and corrosion and extend the service life. Finally, aluminum has strong processability and can be easily extruded into various shapes to meet different heat dissipation requirements, while also having a relatively low cost.

[0053] In the second embodiment of the heat sink 24 proposed by the present invention, the heat sink 24 is a columnar heat sink structure 242. For details, please refer to Figure 7 , the columnar heat dissipation structure 242 is extended toward one end of the heat dissipation slot 11. In this embodiment, a plurality of columnar heat dissipation structures 242 are provided on the heat dissipation surface 22, and the plurality of columnar heat dissipation structures 242 are arranged in an array. The columnar heat dissipation structure 242 is obtained by etching the first metal layer 231, and has good structural consistency with the support layer. This embodiment does not limit the specific shape of the columnar heat dissipation structure 242, which can be cylindrical, prism-shaped, or irregularly columnar. In one embodiment of the present invention, the columnar heat dissipation structure 242 is an elliptical column, which is easy to etch.

[0054] In the third embodiment of the heat sink 24 proposed by the present invention, the heat sink 24 is a mesh heat sink structure 243. For details, please refer to Figure 8 and Fig. 9 The mesh heat dissipation structure 243 is formed with a plurality of crisscross water holes 243a, through which cooling water flows, thereby contacting the side wall of the mesh heat dissipation structure 243 to achieve heat exchange. The mesh heat dissipation structure 243 is made by stamping as a whole, and is fixed to the heat dissipation surface 22 and connected to the composite cover plate by welding.

[0055] In one embodiment of the present invention, each heat dissipation slot 11 is provided with an annular seal 7. For details, please refer to Figure 1 and Figure 2 The annular seal 7 is respectively in contact with the housing 1 and the power device 2, so that the heat dissipation groove 11 of the housing 1, the heat dissipation surface 22 of the power device 2 and the annular seal 7 enclose a closed space, and the coolant flows in the closed space, thereby preventing the coolant from overflowing and causing the power module to contact the liquid and cause a short circuit.

[0056] In order to fix and install the power device 2, the plastic-encapsulated power module assembly 100 also includes a pressing block. For details, please refer to Figure 1 and Figure 2 The pressing block is divided into an end pressing block and an intermediate pressing block. The end pressing block is also a pressing block fixed at both ends of the plastic-encapsulated power module assembly 100. The end pressing block has a limiting groove 42, and an edge of the power device 2 located at the end is fixed in the limiting groove 42; the intermediate pressing block has two limiting grooves 42, and the two limiting grooves 42 are respectively clamped and fixed with two adjacent edges of two adjacent power devices 2, thereby realizing the fixed limit of the three power modules. The design of the end pressing block and the intermediate pressing block can effectively fix the power device 2 and improve the stability and reliability of the module. The end pressing block fixes the edge of the power device 2 through the limiting groove 42, and the intermediate pressing block clamps the edge of the adjacent power device 2 through the two limiting grooves 42. This structural design can ensure that the power module will not be displaced or vibrated during installation and operation. This fixing method not only enhances the mechanical stability of the module, but also effectively reduces the electrical contact problems and thermal fatigue problems caused by the movement of the device, thereby extending the service life of the power module.

[0057] In order to realize the electrical connection between the power device 2 and the control elements such as the motor, the two sides of the power device 2 are respectively provided with connecting pieces 26, one of which is electrically connected to the capacitor copper bus, and the other connecting piece 26 is electrically connected to the three-phase copper bus. For details, please refer to Figure 1 , Figure 2 as well as Figure 4 In the electric vehicle motor controller, the capacitor copper busbar is used to connect the power device 2 with the capacitor to ensure that the capacitor can effectively store and release energy, while also playing the role of filtering and stabilizing the voltage. The three-phase copper busbar is used to transmit the three-phase alternating current output by the power module to the motor, ensuring that the motor can receive stable current and voltage, thereby achieving efficient operation of the motor. The design and application of these two copper busbars are crucial to improving the performance and reliability of the motor controller.

[0058] The present invention also proposes a method for manufacturing a plastic-encapsulated power module assembly 100, which is applied to the manufacture of a composite substrate 23 in the plastic-encapsulated power module assembly 100. The method for manufacturing the plastic-encapsulated power module assembly 100 includes the following steps: S1: obtaining copper material and forming a first copper sheet and a second copper sheet with inconsistent thickness; S2: printing silver paste on the first copper sheet and the second copper sheet; S3: welding the first copper sheet and the second copper sheet; S4: etching a plurality of heat sinks 24 on the side of the first copper sheet facing away from the second copper sheet. The specific structure of the plastic-encapsulated power module assembly 100 refers to the above embodiment. Since the present manufacturing method adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described one by one here.

[0059] The above description is only an exemplary embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A plastic-encapsulated power module assembly, characterized in that: The plastic-encapsulated power module assembly comprises: A shell body, wherein the shell body is formed with a plurality of heat dissipation slots, and the plurality of heat dissipation slots are connected with an external water channel through a heat dissipation water channel; A power device, the power device having a mounting surface and a heat dissipation surface arranged opposite to each other, the heat dissipation surface being arranged toward the heat dissipation slot, a chip being mounted on the mounting surface, the mounting surface being provided with pins extending away from the heat dissipation slot, the heat dissipation surface being provided with a plurality of heat dissipating elements, at least a portion of the structure of each of the heat dissipating elements being located in the heat dissipation slot; and A main control board is arranged on the shell, and the power device is electrically connected to the main control board through the pins.

2. The plastic-encapsulated power module assembly according to claim 1, characterized in that: The power device comprises a composite substrate, the composite substrate is arranged on the heat dissipation surface, and a plurality of heat dissipation elements are bonded to the composite substrate.

3. The plastic-encapsulated power module assembly according to claim 2, characterized in that: The composite substrate includes a first metal layer, a ceramic layer and a second metal layer which are stacked in sequence from one end close to the heat sink to an end away from the heat sink, and a plurality of the heat sinks are bonded to the first metal layer.

4. The plastic-encapsulated power module assembly according to claim 3, characterized in that: The material of the first metal layer and / or the second metal layer is oxygen-free copper; and / or The material of the ceramic layer is silicon nitride.

5. The plastic-encapsulated power module assembly according to any one of claims 1 to 4, characterized in that: The heat sink is a strip-shaped heat dissipation structure, which includes two connecting parts and a bending part. The two connecting parts are respectively arranged at two ends of the bending part, and the two connecting parts are arranged on the heat dissipation surface. The bending part is bent toward the heat dissipation groove.

6. The plastic-encapsulated power module assembly according to any one of claims 1 to 4, characterized in that: The heat sink is a columnar heat sink structure and is extended toward the heat sink.

7. The plastic-encapsulated power module assembly according to any one of claims 1 to 4, characterized in that: The notch of each heat dissipation slot is provided with an annular seal, and the annular seal is respectively in contact with the housing and the power device.

8. The plastic-encapsulated power module assembly according to any one of claims 1 to 4, characterized in that: The plastic-encapsulated power module assembly further comprises a pressing block, wherein the pressing block is provided with a limiting groove facing the power device, and a part of the structure of the power device abuts against the limiting groove for limiting position.

9. The plastic-encapsulated power module assembly according to claim 8, characterized in that: Connecting plates are respectively provided on both sides of the power device, one of the connecting plates is electrically connected to the capacitor copper busbar, and the other connecting plate is electrically connected to the three-phase copper busbar.

10. A method for manufacturing a plastic-encapsulated power module assembly, applied to the manufacture of a composite substrate in a plastic-encapsulated power module assembly as claimed in any one of claims 1 to 9, characterized in that: The steps include: Obtaining copper material and forming a first copper sheet and a second copper sheet having different thicknesses; Printing silver paste on the first copper sheet and the second copper sheet; welding the first copper sheet and the second copper sheet; A plurality of heat dissipation elements are etched on a side of the first copper sheet facing away from the second copper sheet.

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