An embedded power module with double-sided oil cooling

Abstract

This utility model relates to an embedded power module with double-sided oil cooling, including a PCB board. A power chip and copper busbars are mounted on the PCB board. Heat sinks are installed on both the top and bottom sides of the PCB board, and the installation positions of the heat sinks are matched with the power chip. An oil-cooling base is installed outside the heat sink, and the oil-cooling base and the heat sink form an oil-cooling channel. This double-sided oil cooling solution allows for independent heat dissipation from both the top and bottom sides, ensuring that the oil medium can effectively remove heat.

Description

Technical Field

[0001] This utility model relates to the field of power module technology, and in particular to an embedded power module with a double-sided oil-cooled heat dissipation stray symmetry design. Background Technology

[0002] As power electronic systems evolve towards higher power density, higher integration, and higher frequency, traditional power modules (such as molded modules and frame modules) face severe challenges in terms of heat dissipation efficiency, electrical performance, packaging reliability, and production costs. In key areas such as new energy vehicles, industrial frequency converters, and renewable energy converters, modules need to withstand higher currents and switching frequencies, but existing technologies cannot simultaneously meet the requirements for efficient heat dissipation, low stray parameters, high-reliability packaging, and low-cost manufacturing, thus restricting system performance and large-scale application.

[0003] Currently, traditional power modules have shortcomings in terms of heat dissipation and stray parameters. These shortcomings are mainly reflected in the following aspects: 1. Traditional plastic-encapsulated modules rely solely on natural surface convection or limited auxiliary heat dissipation. In high-power-density applications, this makes it difficult to dissipate heat quickly and effectively, easily leading to overheating of the chip and affecting the module's performance and lifespan. For example, in the motor controller of electric vehicles, as power demands increase, the insufficient heat dissipation capacity of the plastic-encapsulated module causes the module to frequently operate at a derating rate, reducing the vehicle's power performance.

[0004] Although the frame module has relatively good heat dissipation capabilities, the difference in heat conduction paths between the chip and the heat dissipation substrate can easily lead to uneven temperature distribution in different areas of the chip, which in turn affects the chip's consistency and reliability.

[0005] 2. The presence of bonding wires in the molded module and the complex electrical connection structure in the frame module introduces significant stray inductance and stray resistance / capacitance. Under high-frequency operating conditions, these stray parameters can lead to voltage spikes and current oscillations, affecting circuit stability and efficiency. For example, in switching power supply applications, stray inductance can cause high voltage spikes in the switching transistor during turn-on and turn-off, increasing transistor losses and the risk of damage. Bonding wires are prone to fatigue fracture under long-term temperature changes and mechanical vibrations, leading to electrical connection failure. Welded or crimped connections in the frame module may also experience poor contact due to thermal expansion and contraction, corrosion, etc., affecting the normal operation of the module.

[0006] 3. Molded packaging materials have relatively low mechanical strength, making them prone to cracking and delamination when subjected to external impacts or vibrations. This affects the module's internal electrical structure and insulation performance. Traditional modules require a separately designed insulation layer to ensure electrical insulation performance, which increases the module's size and cost. Furthermore, in some special application scenarios, the performance of the insulation layer may be affected by environmental factors such as temperature and humidity, reducing the module's reliability.

[0007] 4. The packaging processes for plastic-molded and frame modules are relatively complex, involving multiple materials and process steps, resulting in higher packaging costs and hindering large-scale applications. In traditional packaging processes, processes such as bonding and potting have low production efficiency, making it difficult to meet rapidly growing market demands. At the same time, controlling the yield rate during the production process also faces certain challenges, further increasing production costs.

[0008] Therefore, there is an urgent need for a heat dissipation structure for power modules that can solve the above problems. Utility Model Content

[0009] The present invention aims to provide an embedded power module with a double-sided oil-cooled heat dissipation stray symmetrical design to overcome the shortcomings of the prior art. The technical problem to be solved by the present invention is achieved through the following technical solution.

[0010] According to a first aspect of this application, an embedded power module with double-sided oil cooling is provided, including a PCB board, on which a power chip and a copper busbar are disposed, and heat sinks are installed on both the upper and lower sides of the PCB board. The installation positions of the heat sinks are matched with the power chip, and an oil cooling base is installed outside the heat sinks, the oil cooling base and the heat sinks forming an oil cooling channel.

[0011] Preferably, the radiator is provided with heat dissipation pins, which are arranged in a matrix and located in the oil cooling channel.

[0012] Preferably, the cross-section of the heat dissipation pin is one or more composite structures selected from cylindrical, elliptical, rhomboid, teardrop-shaped, and micro-turbulence fins.

[0013] Preferably, the matrix formed by the heat dissipation pins is consistent with the width of the oil cooling channel, and the height of the heat dissipation pins is consistent with the depth of the oil cooling channel.

[0014] Preferably, the oil-cooled bottom shell located on the same side of the PCB board has an annular structure.

[0015] Preferably, the PCB board is ring-shaped, and the power chips are evenly arranged on the PCB board.

[0016] Preferably, the PCB board is evenly divided into three 120° sector areas, and the three-phase power chips of U, V and W are respectively installed in the sector areas.

[0017] Preferably, the oil cooling base shell has a hexagonal structure, and the oil cooling base shell is provided with a liquid inlet and a liquid outlet, the liquid inlet and the liquid outlet are arranged adjacent to each other and separated by a partition.

[0018] Preferably, the copper busbar includes a positive copper busbar, a negative copper busbar, and a three-phase copper busbar. The positive copper busbar and the negative copper busbar are disposed on the upper and lower sides of the inner ring of the PCB board, and the three-phase copper busbar is disposed on the outer ring of the PCB board.

[0019] Preferably, the surface of the heat sink is provided with a nickel plating layer, the thickness of which is 5-10 μm.

[0020] The embodiments of this utility model have the following advantages: The system employs a double-sided oil cooling solution, with independent heat dissipation at the top and bottom to ensure that the oil medium can fully remove heat. The three-phase symmetrical layout of the circular PCB (UVW at a 120° angle) ensures a high degree of symmetry in the interconnect structure and electromagnetic environment. Compared to traditional layouts of the same power rating, the symmetrical structure significantly improves parameter consistency between different branches, ensuring completely uniform parasitic inductance and zero overall imbalance. Circuit analysis using simulation software shows that the current imbalance is only about 2% after adopting symmetrical packaging, far less than that of traditional power modules. Attached Figure Description

[0021] Figure 1 This is a top view of an embedded power module with double-sided oil cooling according to the present invention. Figure 2 yes Figure 1 An exploded view of the embedded power module with double-sided oil cooling. Figure 3 yes Figure 1 A cross-sectional schematic diagram of an embedded power module with double-sided oil cooling. Figure 4 yes Figure 1 Schematic diagram of the structure of the cold bottom shell of CNPC; Figure 5 yes Figure 1 A top view of the PCB board. Detailed Implementation

[0022] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0023] It should be noted that the above detailed descriptions are exemplary and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0024] like Figures 1 to 5 As shown in one embodiment of this application, the embedded power module with double-sided oil cooling addresses the problems of inefficient heat dissipation, stray parameters affecting electrical performance, complex insulation layer design, and high cost of traditional power modules. This solution focuses on "replacing traditional insulation layers with oil dielectric + double-sided oil cooling + symmetrical design of stray parameters" to construct a novel CIPB (Chip Inlay Power Board). Through innovative application of material properties, optimized structural design, and coordinated parameter control, it achieves a comprehensive improvement in heat dissipation capacity, electrical performance, and system integration, adapting to complex scenario requirements.

[0025] Specifically, this embedded power module includes a PCB board 100, on which a power chip 300 and a copper busbar 400 are mounted. Heat sinks 210 are installed on both the top and bottom sides of the PCB board 100. The installation positions of the heat sinks 210 are matched with those of the power chip 300. An oil-cooled base shell 220 is installed outside the heat sink 210. The oil-cooled base shell 220 and the heat sink 210 form an oil-cooling channel 221.

[0026] In this embodiment, the heat sink 210 is provided with heat dissipation pins 211 arranged in a matrix and located in the oil cooling channel 221. The cross-section of the heat dissipation pins 211 is one or more composite structures selected from cylindrical, elliptical, rhomboid, teardrop, and micro-turbulence fins. The matrix formed by the heat dissipation pins 211 has the same width as the oil cooling channel 221, and the height of the heat dissipation pins 211 has the same depth as the oil cooling channel 221.

[0027] The heat sink 210 is made of high thermal conductivity materials (such as oxygen-free copper, copper T2 / T3, copper-tungsten alloy, aluminum-silicon composite material) to make the upper and lower heat sinks 210. The surface that is in direct contact with the chip needs to be flattened. The spacing and diameter of the heat sink pins 211 of the upper and lower heat sinks 210 need to be consistent to facilitate the fit with the oil cooling channel 221 structure at the bottom of the PCB after embedding.

[0028] The surface of the copper radiator 210 is nickel-plated with a thickness of 5-10μm to enhance its oxidation resistance and wettability with bonding materials (such as silver paste, solder pads, solder paste, copper paste, TLPS, sintered silver film, conductive adhesive).

[0029] In this embodiment, the PCB board 100 is ring-shaped, and the power chips 300 are evenly arranged on the PCB board 100. The PCB board 100 is evenly divided into three 120° sector regions 101, and the three-phase power chips 300 of U, V and W are respectively installed in the sector region 101. The distance from the geometric center of the three-phase module to the center of the circle is strictly equal to ensure physical symmetry and achieve ESL balance among the three phases.

[0030] Embedded cavities adapted to the integrated circuit are machined within three fan-shaped areas 101 of the PCB using laser etching or precision milling. A multi-layer PCB design is employed, with interconnect lines and heat dissipation / conductive paths layered around the cavities. The PCB substrate with the chip integrated circuit to be embedded is placed in a vacuum chamber, and the cavities are plasma-cleaned to remove contaminants and oxide layers, improving the adhesion between the integrated circuit and the PCB. Under vacuum conditions, a thermoforming head applies pressure and temperature to the integrated circuit, slowly pressing it into the PCB cavity. During the thermoforming process, micro-bumps on the chip surface establish electrical connections with the internal wiring of the PCB.

[0031] The oil-cooled base shell 220 has a hexagonal annular structure, with an inlet and an outlet. The inlet and outlet are arranged adjacent to each other and separated by a partition. The oil-cooling channel 221 adopts a diversion channel design, with independent upper and lower heat dissipation, ensuring that the oil medium can flow fully through the gaps of the heat dissipation pins 211 to carry away heat. The inlet and outlet are connected to an external oil-cooling circulation system.

[0032] In oil cooling channel 221, synthetic esters or silicone oils with high insulation strength, high thermal conductivity, and low viscosity are selected as the insulating cooling medium. The oil undergoes vacuum dehydration and impurity removal pretreatment to ensure stable dielectric properties.

[0033] In this embodiment, the copper busbar 400 includes a positive copper busbar 410, a negative copper busbar 420, and a three-phase copper busbar 430. The positive copper busbar 410 and the negative copper busbar 420 are disposed on the upper and lower sides of the inner ring of the PCB board 100, and the three-phase copper busbar 430 is disposed on the outer ring of the PCB board 100.

[0034] The fabrication method of the above-mentioned double-sided oil-cooled embedded power module is as follows: 1. Heat sink design and fabrication: Oxygen-free copper is selected as the material for the upper and lower heat sinks because it has an extremely high thermal conductivity and can efficiently conduct the heat generated by the chip during operation. For the heat sink surface that is in direct contact with the chip, a precision grinding process is used to treat its flatness, ensuring that the surface flatness error is controlled within an extremely low range (usually no more than 0.01mm), so as to reduce the contact thermal resistance between the chip and the heat sink and improve the heat conduction efficiency. The heat dissipation pins of the upper and lower heat sinks must be manufactured strictly according to the design parameters, with the spacing and diameter of the upper and lower heat dissipation pins remaining consistent. Precision CNC machining can be used, employing specialized tools to cut the material, forming heat dissipation pin structures of different shapes and neat arrangements (such as cylindrical, elliptical, rhomboid, teardrop shapes, etc.) or a composite structure of a main heat dissipation column and micro-turbulence fins. This structural design must also consider the subsequent compatibility with the oil-cooling channels at the bottom of the PCB, ensuring that the heat dissipation pins can be smoothly embedded into the PCB and fit tightly against the channel structure, guaranteeing smooth flow of the oil medium. The surface of the heat sink is nickel-plated using an electroplating process. First, the heat sink surface undergoes pretreatment, including degreasing, rust removal, and activation, to improve the adhesion between the plating layer and the substrate. Then, the heat sink is immersed in a nickel plating solution, where electrolysis causes nickel ions to deposit on the surface, forming a uniform nickel layer. The thickness of the nickel plating layer needs to be controlled within a suitable range (generally 5-10 μm) to enhance the heat sink's oxidation resistance, preventing oxidation during subsequent processing and use, and to improve wettability with the silver paste, ensuring uniform spread and good bonding during sintering.

[0035] 2. Sintering of chip and heat sink: Chip pretreatment: The IGBT / SiC chips are cleaned and surface-treated to remove contaminants and oxide layers from the chip surface. Ultrasonic cleaning technology can be used, followed by drying to ensure a clean chip surface. Silver paste application: Using high-precision dispensing equipment or stencil printing technology, a certain thickness of silver paste is evenly applied to the designated locations on the lower heatsink. The amount and thickness of the silver paste application must be strictly controlled to ensure a good metallurgical bond between the chip and the heatsink, while avoiding excessive or insufficient silver paste that could lead to poor bonding. Chip placement: Using a high-precision vision positioning system, the pre-treated chip is precisely placed on the lower heatsink coated with silver paste, ensuring that the chip's positional deviation is within the design tolerance range (usually no more than 0.05mm). Upper heatsink placement: Similarly, silver paste is applied to the corresponding locations on the upper heatsink using dispensing or printing technology, and then precisely aligned with the upper surface of the chip, ensuring the alignment accuracy between the upper and lower heatsinks and the chip. Sintering Process: The assembled unit is placed in a sintering furnace, and an inert gas (such as nitrogen) is introduced into the furnace to purge air and prevent oxidation of the chip and heat sink at high temperatures. Heating is performed according to a preset temperature rise curve, with the heating rate strictly controlled to avoid thermal stress caused by rapid temperature changes. During heating, a certain pressure is simultaneously applied to the entire assembly, and this pressure must be evenly distributed. Once the set sintering temperature is reached (determined based on the characteristics of the silver paste, generally 250-300℃), this temperature is maintained for a period of time to allow the silver paste to melt and diffuse with the chip and heat sink surfaces, forming a strong metallurgical bond. Finally, the assembly is slowly cooled to room temperature according to a preset cooling curve, with the cooling rate also controlled to reduce internal stress.

[0036] 3. PCB Board Design: A circular PCB substrate with high thermal conductivity should be selected. If a metal-based PCB (such as aluminum-based or copper-based) or high thermal conductivity copper-clad laminate is used, its thermal conductivity needs to be determined based on the heat dissipation requirements of the power module (generally not less than 2W / (m・K)). The diameter of the substrate should be selected based on the installation dimensions and layout requirements of the three-phase power module. Using the center of the circular PCB substrate as the center of symmetry, EDA software was used to design and divide the substrate into three 120° sector regions, which serve as the mounting areas for the U, V, and W three-phase power modules, respectively. During the division process, it was necessary to ensure that the angular error of the three regions was controlled within a minimal range to guarantee symmetry. During the design process, the distance from the geometric center of the three-phase module to the center of the circle is precisely calculated to ensure that the three are strictly equal. The installation coordinates of each phase module can be clearly defined in the PCB design file through coordinate positioning to achieve physical symmetry, thereby ensuring that the ESL (Equivalent Series Inductance) of the three is balanced.

[0037] Based on the dimensions of the chip-double-sided heatsink integrated assembly, suitable cavity structures are designed within the three sector-shaped areas of the circular PCB. The fabrication process employs either laser etching or precision mechanical milling. If laser etching is used, appropriate laser power and etching speed must be selected to ensure the dimensional accuracy and surface quality of the cavity, avoiding excessive damage to the PCB substrate. If precision mechanical milling is used, high-precision milling cutters and CNC milling machines are required, with precise programming to control the milling path and depth, ensuring a good fit between the cavity and the integrated assembly. A multilayer PCB design is employed, with interconnects and heat dissipation conductive paths laid out on different layers around the cavity. The interconnects must be designed according to the electrical connection requirements of the power module to ensure smooth current transmission and low impedance. Heat dissipation conductive paths should be as thick and short as possible to improve heat dissipation efficiency. Electrical connections and heat conduction between layers are achieved through vias; the number and distribution of vias must be rationally designed. The PCB substrate into which the chip integration is to be embedded is placed in a vacuum chamber, the chamber is closed, and a vacuum is evacuated to a certain degree. Then, an appropriate amount of inert gas (such as argon) or reactive gas (such as oxygen) is introduced, and plasma is generated by a plasma generator. The plasma physically bombards and chemically reacts with contaminants and oxide layers within the chamber, decomposing and removing them. The cleaning time is determined based on the degree of contamination. After cleaning, the vacuum state is maintained for subsequent operations to avoid secondary contamination. In a vacuum environment, align the chip-double-sided heatsink integrated assembly with the cavity on the PCB. Apply pressure and temperature (determined based on the PCB material and silver paste properties) to the integrated assembly using a thermoforming head. During thermoforming, control the rate of pressure and temperature application, slowly pressing the integrated assembly into the PCB cavity. During this process, the micro-bumps on the chip surface and the internal wiring of the PCB achieve close contact through pressure and temperature, resulting in plastic deformation and a reliable electrical connection. After thermoforming, slowly cool and depressurize to ensure connection stability.

[0038] 4. Design of the oil-cooled base: Design a suitable cover plate based on the location and size of the upper and lower heat sinks. The cover plate material can be a high thermal conductivity, high strength metal material (such as aluminum alloy or copper alloy). The connection surface between the cover plate and the PCB needs to be sealed, using oil-resistant rubber sealing rings or sealant to ensure that the oil medium does not leak. Install the cover plate on the PCB at the corresponding positions of the upper and lower heat sinks using screws or clips to form upper and lower oil cooling channels. A flow distribution channel structure is designed inside the cover plate. The shape and size of the flow distribution channel need to be designed according to the layout of the heat dissipation pins and the flow rate requirements of the oil medium. The flow distribution channel should be able to evenly distribute the oil medium into the gaps between the heat dissipation pins, ensuring that each heat dissipation pin is fully surrounded by the oil medium, thereby improving heat dissipation efficiency. The upper and lower oil cooling channels adopt an independent design, with their respective flow distribution channels being independent of each other, to avoid the mixing or interference of the oil medium between the upper and lower channels; Design inlet and outlet interfaces at appropriate locations on the cover plate, ensuring the interface type matches the piping of the external oil cooling circulation system (e.g., using standard threaded interfaces). Connect the inlet and outlet of the channel to the external oil cooling circulation system via piping, ensuring a tight, leak-free connection. After connection, a pressure test must be performed to ensure that the oil medium does not leak under a certain pressure.

[0039] 5. Selection and Treatment of Cooling Medium: Based on the operating environment and performance requirements of the power module, a suitable oil medium is selected. Candidate oil media include synthetic esters and silicone oils. The following key performance indicators must be considered during selection: insulation strength, thermal conductivity, and viscosity. Simultaneously, factors such as the oil medium's temperature resistance, chemical stability, and compatibility with materials must also be considered to ensure long-term stable operation under the power module's operating conditions. The screened oil is placed in a vacuum dehydration device, where a certain vacuum level is drawn, and the oil is heated to a specific temperature. Under vacuum and heating conditions, the water in the oil evaporates and is extracted, achieving dehydration. The dehydration time is determined based on the water content of the oil, continuing until the water content drops to a specified value.

[0040] Precision filtration equipment is used to remove impurities from the dehydrated oil. The filter element of the equipment needs to have a micron-level precision to effectively remove solid particulate impurities from the oil. The oil flow rate must be controlled during filtration to ensure filtration effectiveness. After impurity removal, the oil is sampled and tested to ensure that the impurity content meets requirements, thus guaranteeing the stability of the dielectric properties of the oil medium.

[0041] The embodiments of this utility model have the following advantages: The technology adopts a double-sided oil cooling solution with independent heat dissipation on the top and bottom to ensure that the oil medium can fully remove heat. Compared with the traditional water-cooled frame module, the overall thermal resistance is significantly reduced through a variety of integration solutions such as sintering instead of bonding, PCB embedded integration, bidirectional balanced heat dissipation, and shortening of the equivalent thermal resistance path. The three-phase symmetrical layout of the circular PCB (UVW at a 120° angle) ensures a high degree of symmetry in the interconnect structure and electromagnetic environment. Compared to traditional layouts of the same power rating, the symmetrical structure significantly improves the parameter consistency between different branches, ensuring completely uniform parasitic inductance and an overall imbalance of zero. Circuit analysis using simulation software shows that with symmetrical packaging, the current imbalance is only about 2%, far less than that of traditional power modules. Traditional frame module production requires at least eight independent processes, including chip mounting, wire bonding, and insulation potting. This complexity results in a yield rate of approximately 92%. The novel embedded module involved in this technical solution utilizes an integrated process encompassing chip sintering, heat sink integration, and PCB embedding, significantly reducing the number of processes. Furthermore, by employing precise technologies such as visual positioning and vacuum sintering, the yield rate is increased to 98%. Based on an annual production of 100,000 modules, traditional modules, due to their complex processes and low yield rate, increase production costs by approximately 15% (including rework and scrap costs). The module of this invention can reduce production costs by approximately 12%, significantly improving production efficiency.

[0042] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0043] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments of this application described herein can be implemented in sequences other than those illustrated or described herein.

[0044] Furthermore, the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or apparatus.

[0045] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways, such as rotated 90 degrees or in other orientations, and the spatial relative descriptions used herein will be interpreted accordingly.

[0046] In the detailed description above, reference has been made to the accompanying drawings, which form part of this document. In the drawings, similar symbols typically identify similar parts unless the context otherwise indicates otherwise. The illustrated embodiments described in the detailed specification, drawings, and claims are not intended to be limiting. Other embodiments may be used and other changes may be made without departing from the spirit or scope of the subject matter presented herein.

[0047] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A double-sided oil-cooled heat-dissipation embedded power module, comprising a PCB board, wherein a power chip and a copper bar are arranged on the PCB board, characterized in that, Heat sinks are installed on both the top and bottom sides of the PCB board. The installation positions of the heat sinks are matched with the power chip. An oil-cooled base is installed outside the heat sink, and the oil-cooled base and the heat sink form an oil-cooling channel.

2. The embedded power module with double-sided oil cooling according to claim 1, characterized in that, The radiator is provided with heat dissipation pins, which are arranged in a matrix and located in the oil cooling channel.

3. The embedded power module with double-sided oil cooling according to claim 2, characterized in that, The cross-section of the heat dissipation pin is one or more composite structures selected from cylindrical, elliptical, rhomboid, teardrop, and micro-turbulence fins.

4. The embedded power module with double-sided oil cooling according to claim 2, characterized in that, The matrix formed by the heat dissipation pins has the same width as the oil cooling channel, and the height of the heat dissipation pins has the same depth as the oil cooling channel.

5. The embedded power module with double-sided oil cooling according to claim 1, characterized in that, The oil-cooled bottom shell located on the same side of the PCB board has a ring structure.

6. The embedded power module with double-sided oil cooling according to claim 5, characterized in that, The PCB board is ring-shaped, and the power chips are evenly arranged on the PCB board.

7. The embedded power module with double-sided oil cooling according to claim 6, characterized in that, The PCB board is evenly divided into three 120° sector areas, and the three-phase power chips of U, V and W are respectively installed in the sector areas.

8. The embedded power module with double-sided oil cooling according to claim 7, characterized in that, The oil-cooled bottom shell has a hexagonal structure and is provided with an inlet and an outlet. The inlet and outlet are arranged adjacent to each other and separated by a partition.

9. The embedded power module with double-sided oil cooling according to claim 6, characterized in that, The copper busbar includes a positive copper busbar, a negative copper busbar, and a three-phase copper busbar. The positive copper busbar and the negative copper busbar are disposed on the upper and lower sides of the inner ring of the PCB board, and the three-phase copper busbar is disposed on the outer ring of the PCB board.

10. The embedded power module with double-sided oil cooling according to claim 1, characterized in that, The surface of the heat sink is provided with a nickel plating layer, the thickness of which is 5-10 μm.

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