Power modules, inverters and vehicles

Abstract

The present application provides a power module, an inverter and a vehicle. The power module includes a chip, a heat-conducting layer and a heat dissipation component. The thermal conductivity of the heat-conducting layer is greater than or equal to 200W / mK. The heat dissipation component includes a heat dissipation shell, which is arranged to form a receiving space. The chip and the heat-conducting layer are arranged in the receiving space. At least part of the heat dissipation shell is a hollow shell, and at least one side of the chip is in contact with the hollow shell through the heat-conducting layer. The hollow shell is filled with a cooling medium for cooling the heat-conducting layer, and the cooling medium is an insulating fluid medium. The power module of the present application utilizes a heat dissipation shell and a cooling medium with insulating properties to achieve insulation and sealing of the chip. There is no need to set up an additional ceramic layer as an insulating layer. This can significantly reduce the thermal resistance of the power module and improve the heat dissipation performance and reliability of the power module.

Description

Technical Field

[0001] The present application relates to power devices, and in particular to a power module, an inverter and a vehicle. Background Art

[0002] Insulated gate bipolar transistor (IGBT) power modules are core components for DC / AC conversion in electric vehicles. The rapid development of electric vehicles in recent years has placed higher demands on the performance of IGBT power modules, such as higher power conversion efficiency, smaller size and weight, and higher reliability that can meet the stringent requirements of automotive regulations.

[0003] In order to ensure the reliability of power devices, the existing packaging solution is to use a ceramic layer to achieve insulation between the chip and the outside world, and then use a heat dissipation component arranged outside the ceramic layer to dissipate heat from the chip. In this packaging solution, the ceramic layer provides an insulated packaging space for the chip, and the heat dissipation component dissipates heat from the chip. The ceramic layer and the heat dissipation component can be connected through a silicone material. In this way, the heat generated by the chip needs to be conducted to the heat dissipation component through the ceramic layer and the silicone layer for dissipation. Since the thermal conductivity of the ceramic layer is poor, and the power component often requires instantaneous high-voltage-low-voltage conversion, the heat generated is relatively high. It is often impossible to transfer the heat generated by the chip to the outside in time, which can easily lead to damage to the chip, thereby reducing the reliability of the power module. Summary of the Invention

[0004] The present application provides a power module, an inverter and a vehicle to improve the reliability of the power module.

[0005] In a first aspect, the present application provides a power module, which includes a chip, a heat-conducting layer and a heat dissipation component, wherein the thermal conductivity of the heat-conducting layer is greater than or equal to 200 W / mK; the heat dissipation component includes a heat dissipation shell, which is arranged to form a accommodating space, and the chip and the heat-conducting layer are arranged in the accommodating space; wherein at least a portion of the heat dissipation shell is a hollow shell, and at least one side of the chip is in contact with the hollow shell through the heat-conducting layer; the hollow shell is filled with a cooling medium for cooling the heat-conducting layer, and the cooling medium is an insulating fluid medium.

[0006] In the power module of the present application, the chip and the heat-conducting layer are arranged in the accommodation space formed by the heat-dissipating housing. Since a heat-conducting layer with a thermal conductivity greater than or equal to 200W / mK is used, the heat-conducting layer can have a super-high heat transfer efficiency compared to the ceramic layer, and the heat generated by the chip can be quickly transferred to the heat-dissipating component through the heat-conducting layer. At the same time, in the power module of the present application, the heat-dissipating housing of the heat-dissipating component is at least partially a hollow housing, and the hollow housing is filled with an insulating fluid medium as a cooling medium. In addition to promptly absorbing the heat transferred from the heat-conducting layer to the heat-dissipating housing, the cooling medium can also provide an insulating packaging environment for the chip, increase the insulation between the chip and the external environment components, and thus improve the reliability of the power component. Therefore, the power module of the present application utilizes the heat-dissipating housing and the cooling medium with insulating properties to achieve the insulation and sealing of the chip, without the need to additionally set up a ceramic layer as an insulating layer, thereby eliminating the thermal resistance of the ceramic layer traditionally used as an insulating layer, and thus significantly reducing the thermal resistance of the power module and improving the heat dissipation performance of the power module.

[0007] In addition, the cooling medium used in the power module of the present application can be an oil-cooling medium, which can share a cooling system with the oil-cooled motor, thereby solving the problem that the water-cooling system and the oil-cooled motor cannot be deeply integrated.

[0008] In an optional implementation, the hollow shell is provided with an inlet and an outlet, and the cooling medium can flow into the hollow shell from the inlet and flow out from the outlet. The cooling medium can be a flowing medium and can be recycled.

[0009] In an optional implementation, heat dissipation teeth are provided in the hollow shell, and the cooling medium can flow through the gaps between the heat dissipation teeth. By providing the heat dissipation teeth, the heat dissipation area can be increased and the heat dissipation efficiency can be improved.

[0010] In an optional implementation, heat dissipation teeth are provided on the outside of the hollow shell. By providing the heat dissipation teeth, the heat dissipation area can be increased and the heat dissipation efficiency can be improved.

[0011] In one optional implementation, the hollow housing includes a packaging plate and a cover plate. The packaging plate is disposed proximate to the chip, and the cover plate is disposed on a side of the packaging plate facing away from the chip. In one optional implementation, a groove is provided on a side of the cover plate facing the packaging plate. In another optional implementation, a groove is provided on a side of the packaging plate facing the cover plate.

[0012] In one optional implementation, the difference between the thermal expansion coefficient of the chip and the thermal expansion coefficient of the heat-conducting layer is less than or equal to 50%. Using a heat-conducting layer with a thermal expansion coefficient similar to that of the chip can reduce thermal stress between the chip and the heat-conducting layer, further improving the reliability of the connection between the chip and the heat-conducting layer.

[0013] In one optional implementation, the thickness of the thermal conductive layer is greater than or equal to 2 mm and less than or equal to 5 mm. For transient operating conditions of the power module, such as during high-voltage to low-voltage conversion, using a thicker thermal conductive layer can effectively equalize the temperature, increase the thermal capacity of the entire module, and reduce the junction temperature of the power module under transient conditions.

[0014] In an optional implementation, the material of the heat conducting layer is selected from at least one of copper, aluminum or diamond.

[0015] In an optional implementation, the fluid medium includes cooling oil.

[0016] In a second aspect, the present application also provides an inverter, which may include auxiliary components and the power module of the present application.

[0017] The auxiliary components include but are not limited to switches, capacitors, current sensors, and AC wiring sockets.

[0018] In a third aspect, the present application further provides a vehicle, which may include the inverter of the present application. The vehicle may be a new energy vehicle.

[0019] The technical effects that can be achieved in the second and third aspects mentioned above can be described with reference to the corresponding effects in the first aspect mentioned above, and will not be repeated here.

[0020] Among them, the data in the above-mentioned possible implementation methods of the present application, such as the thermal conductivity coefficient of the heat-conducting layer, the thickness of the heat-conducting layer and other data, when measured, the values ​​within the engineering measurement error range should be understood to be within the range specified in the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the structure of an existing IGBT power module;

[0022] Figure 2 Schematic diagram of the structure of a power module according to an embodiment;

[0023] Figure 3 This is a schematic diagram of the exploded structure of a power module according to an embodiment;

[0024] Figure 4 A schematic diagram of the cross-sectional structure of a power module according to an embodiment;

[0025] Figure 5 This is a schematic structural diagram of a power module according to another embodiment of the present application;

[0026] Figure 6 This is a schematic diagram of the connection structure of a vehicle according to an embodiment of the present application.

[0027] Reference numerals:

[0028] 10-power module; 11-chip; 12-heat dissipation assembly; 121-heat dissipation housing; 122-hollow housing; 1221-packaging board;

[0029] 1222 - cover plate; 123 - heat dissipation teeth; 13 - insulation layer; 14 - thermal conductive layer; 15 - power terminal; 16 - signal terminal;

[0030] 17-support layer; 18-solder; 19-adhesive layer; 20-seal;

[0031] 100-Vehicle; 101-Power battery; 102-Inverter; 103-Engine; 104-Power assembly. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of this application clearer, this application will be further described in detail below with reference to the accompanying drawings.

[0033] The terms used in the following embodiments are only for the purpose of describing specific embodiments and are not intended to limit the present application. As used in the specification and appended claims of this application, the singular expressions "a", "an", "said", "above", "the", and "this" are intended to also include expressions such as "one or more", unless the context clearly indicates otherwise.

[0034] References to "one embodiment" or "some embodiments" in this specification mean that a particular feature, structure, or characteristic described in conjunction with that embodiment is included in one or more embodiments of the present application. Thus, phrases such as "in one embodiment," "in some embodiments," "in other embodiments," and "in yet other embodiments" appearing in various places in this specification do not necessarily refer to the same embodiment, but rather mean "one or more but not all embodiments," unless otherwise specifically emphasized. The terms "including," "comprising," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0035] Figure 1This is a schematic diagram of the structure of an existing IGBT power module. In its packaging structure, an insulating layer 13, such as a ceramic layer, is generally provided between the chip 11 and the heat dissipation component 12 to achieve insulation between the chip 11 and the outside. The insulating layer 13 and the heat dissipation component 12 are usually connected by an adhesive layer 19. The adhesive layer 19 can be a silicone material layer to achieve sufficient contact between the insulating layer 13 and the heat dissipation component 12. Among them, a support layer 17 can also be provided between the chip 11 and the insulating layer 13 to prevent the insulating layer 13 from directly contacting the chip 11 and affecting the connection of the chip. During the operation of the IGBT power module, the heat generated by the chip 11 can be transferred to the heat dissipation component 12 in sequence through the support layer 17, the insulating layer 13 and the adhesive layer 19. In this packaging structure, due to the low thermal conductivity of the insulating layer 13, the thermal resistance from the chip 11 to the heat dissipation component 12 is high, and the heat generated by the chip 11 cannot be discharged in time, thereby affecting the reliability of the operation of the chip 11.

[0036] In order to solve the above problems, the present application provides a power module 10. Figure 2 FIG. 1 is a schematic structural diagram of a power module 10 according to an embodiment of the present invention. Figure 3 FIG. 1 is a schematic diagram of an exploded structure of a power module 10 according to an embodiment of the present invention. Figure 2 and Figure 3 As shown, the power module 10 includes a chip 11, a heat-conducting layer 14 and a heat-dissipating component 12, and the heat-dissipating component 12 is used to package the chip 11 and the heat-conducting layer 14. Figure 3 As shown, a power module 10 may include multiple chips 11 , which may be interconnected. The chips 11 may implement signal input and output through power terminals 15 and signal terminals 16 .

[0037] Figure 4 FIG. 1 is a schematic diagram of a cross-sectional structure of a power module 10 according to an embodiment of the present invention. Figure 4 As shown, in the power module 10 of the embodiment of the present application, a heat-conducting layer 14 is provided on at least one side of the chip 11, wherein a support layer 17 can be provided between the heat-conducting layer 14 and the chip 11, with one end of the support layer 17 connected to the chip 11 and the other end connected to the heat-conducting layer 14. The support layer 17 and the chip 11 can be soldered together using solder 18, and the area of ​​the support layer 17 is smaller than the surface area of ​​the chip 11. The provision of the support layer 17 can provide a protective space for the chip 11 in the thickness direction of the chip 11, preventing the heat-conducting layer 14 from directly contacting the chip 11 and causing compression of the chip 11. In addition, the protective space can also facilitate the connection between the chips 11, making it easier to install a connecting circuit board or wires.

[0038] Continue to refer to Figure 4 ,by Figure 4Taking the direction shown as an example, in one embodiment of the present application, a heat-conducting layer 14 can be provided above the chip 11. The heat-conducting layer 14 can be connected to the chip 11 through a supporting layer 17, and the surface of the heat-conducting layer 14 on the side away from the chip 11 is in direct contact with the heat dissipation component 12. In this way, the heat generated during the operation of the chip 11 can first be conducted to the heat-conducting layer 14 through the supporting layer 17, and then conducted to the heat dissipation component 12 through the heat-conducting layer 14, and then transmitted outward through the heat dissipation component 12. In the embodiment of the present application, the thermal conductivity of the heat-conducting layer 14 is greater than or equal to 200W / mK. In this way, the heat-conducting layer 14 can be used to achieve rapid heat transfer, so as to conduct the heat generated by the chip 11 to the heat dissipation component 12 in a timely manner.

[0039] Figure 5 This is a structural diagram of a power module 10 according to another embodiment of the present application. Figure 5 As shown, the thermal conductive layer 14 can be disposed above the chip 11 or below the chip 11. Furthermore, the thermal conductive layer 14 can be disposed both above and below the chip 11. This application does not limit the specific location of the thermal conductive layer 14, and the thermal conductive layer 14 can be adjusted based on the installation location of the power module and the heat dissipation environment.

[0040] The difference between the thermal expansion coefficient of the heat-conducting layer 14 and the thermal expansion coefficient of the heat-conducting layer 14 can be less than or equal to 50%. This can reduce the thermal stress between the chip 11 and the heat-conducting layer 14, avoid cracking of the connection between the chip 11 and the heat-conducting layer 14 due to a large difference in thermal expansion coefficients, and further improve the reliability of the connection between the chip 11 and the heat-conducting layer 14. For example, the material used for the heat-conducting layer 14 can be selected from at least one of copper, aluminum, or diamond.

[0041] In one embodiment, the thickness of the thermal conductive layer 14 is greater than or equal to 2 mm and less than or equal to 5 mm. For transient operating conditions of the power module 10, such as during high-voltage to low-voltage conversion, a thicker thermal conductive layer 14 can effectively equalize the temperature, increase the thermal capacity of the entire module, and reduce the junction temperature of the power module 10 under transient operating conditions.

[0042] Refer to Figures 2 to 5 In the power module 10 of the embodiment of the present application, the heat dissipation assembly 12 includes a heat dissipation housing 121. The heat dissipation housing 121 can enclose a space for accommodating the chip 11 and the heat conducting layer 14 ( Figure 4 and Figure 5 Only a portion of the heat dissipation housing 121 is shown, not the entire housing 121. The chip 11 and the thermally conductive layer 14 are located within this housing. The heat dissipation assembly 12 provides packaging and protection for the chip 11 and the thermally conductive layer 14. The power terminals 15 and signal terminals 16 connected to the chip 11 can extend outside the heat dissipation housing 121 to connect to external circuits.

[0043] Refer to Figure 4 and Figure 5 In one embodiment of the present application, at least a portion of the heat dissipation housing 121 is a hollow housing 122, wherein the hollow housing 122 can be filled with a cooling medium to cool the heat conductive layer 14. The cooling medium can be a circulatory cooling medium. For example, a cooling medium inlet and outlet can be provided at different locations in the hollow housing 122 to facilitate the inflow and outflow of the cooling medium. After flowing out of the hollow housing 122, the cooling medium can enter an external cooler to cool the cooling medium.

[0044] When setting the position of the hollow shell 122, it can be set according to the heat dissipation position of the power module 10. Figure 4 As shown, a hollow shell 122 can be provided at both the upper and lower parts of the chip 11. When the heat generated by the chip 11 is transferred upward, it can be transferred to the hollow shell 122 through the support layer 17 and the heat-conducting layer 14 for heat dissipation; when the heat generated by the chip 11 is transferred downward, the heat can be directly transferred to the hollow shell 122 for heat dissipation. The provision of the heat-conducting layer 14 can achieve a rapid temperature equalization effect. Therefore, compared with the heat dissipation path below, the heat dissipation path above can effectively prevent heat accumulation in a certain part. In addition, as Figure 5 As shown, the hollow housing 122 can also be separately provided below the chip 11. The heat generated by the chip 11 is transferred to the heat dissipation assembly 12 through the heat conductive layer 14 provided below. The specific location of the hollow housing 122 is not particularly limited in this application, as long as it can effectively dissipate heat for the chip 11.

[0045] like Figure 4 and Figure 5 As shown, the heat dissipation assembly 12 may further include heat dissipation teeth 123 disposed within the hollow housing 122. When the cooling medium circulates within the hollow housing 122, the heat dissipation teeth 123 can increase the contact area between the cooling medium and the hollow housing 122, thereby improving the heat dissipation effect. Furthermore, the heat dissipation teeth 123 can also be disposed on the outside of the hollow housing 122. When the heat dissipation teeth 123 are disposed on the outside of the hollow housing 122, the contact area between the hollow housing 122 and the external environment can be increased, thereby improving the heat dissipation effect.

[0046] Continue to refer to Figure 4 and Figure 5In one embodiment of the present application, the hollow shell 122 may be an integrally formed structure or a split structure. When the hollow shell 122 is a split structure, it may include a packaging plate 1221 and a cover plate 1222, wherein the packaging plate 1221 is used to contact the heat-conducting layer 14, and the cover plate 1222 is covered on the surface of the packaging plate 1221. A groove is provided on the side of the cover plate 1222 facing the packaging plate 1221, so that when the cover plate 1222 is covered on the packaging plate 1221, a hollow cavity can be formed between the packaging plate 1221 and the cover plate 1222 for filling with a cooling medium. Among them, when the hollow shell 122 is composed of a packaging plate 1221 and a cover plate 1222, a sealing member 20, such as a sealing strip, may be provided between the packaging plate 1221 and the cover plate 1222 to achieve a sealed connection between the packaging plate 1221 and the cover plate 1222 to prevent leakage of the cooling medium.

[0047] Among them, in the power module 10 of the embodiment of the present application, the cooling medium passed into the hollow shell 122 is an insulating fluid medium. As an exemplary illustration, the cooling medium can be selected as oil, for example. The insulating cooling medium passed into the hollow shell 122 can be used as an insulating layer of the heat dissipation component to achieve the insulation effect of the power module. In this packaging method, there is no need to set up an insulating layer separately, thereby achieving the effect of simplifying the power module structure. At the same time, oil is selected as the cooling medium. When the power module is used in an electric vehicle, for example, the cooling oil of the motor can be used as the cooling medium, thereby achieving deep integration with the motor system of the electric vehicle.

[0048] and Figure 1 Compared with the structure of the power module with water cooling structure shown in FIG, the power module of the present application has the following advantages:

[0049] 1) Low thermal resistance and high heat capacity: The test results show that when the cooling medium inlet flow rate is 5lpm, Figure 4 The thermal resistance of the double-sided cooling power module is 0.083℃ / W, which is comparable to Figure 1 Compared with the double-sided silicone grease water-cooled power module shown in the figure, the thermal resistance is reduced by 1 / 3. For the working condition under transient fluctuation loss input, the simulation results show that under relatively low frequency input loss, compared with Figure 1 For the water-cooled power module with double-sided silicone grease of the structure shown, the maximum junction temperature of the power module of the present application is reduced by nearly 30°C. This result shows that the thermal capacity of the power module of the present application is significantly improved.

[0050] 2) The cooling medium used in this application is an insulating medium. Using an insulating medium with excellent heat dissipation performance as a cooling medium not only improves the heat dissipation performance of the entire power module, but also provides insulation for the entire power module. Testing has shown that the power module in this application operates safely and reliably, creating the potential for deep integration with the motor system of electric vehicles.

[0051] Based on the same technical concept, the present application provides an inverter, which may include a power module of an embodiment of the present application. The number of power modules may be multiple, and multiple power modules can be connected in parallel through a synchronization signal interface. In addition, the inverter of the present application may also include a connection component, wherein the connection component includes but is not limited to at least one of a switch, a capacitor, a current sensor, and an AC terminal block. The components such as the switch, capacitor, current sensor, and AC terminal block can be electrically connected to the terminal blocks of the power module respectively.

[0052] Based on the same technical concept, the present application provides a vehicle, Figure 6 This is a schematic diagram of the connection structure of a vehicle in this application, such as Figure 6 As shown, the vehicle 100 may include an inverter 102 according to an embodiment of the present application, and may also include a power battery 101, an engine 103, and a power assembly 104. The power battery 101 is connected to the engine 103 via the inverter 102. The inverter 102 is used to convert the direct current (DC) power of the power battery 101 into alternating current (AC) power and supply it to the engine 103. The engine 103 is connected to the power assembly 104 to drive the power assembly 104.

[0053] The above are only specific embodiments of the present application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A power module, characterized in that: The chip comprises a heat-conducting layer and a heat-dissipating component, wherein the heat-conducting layer has a thermal conductivity greater than or equal to 200W / mK; The heat dissipation assembly includes a heat dissipation housing, which is surrounded by a receiving space, and the chip and the heat conductive layer are arranged in the receiving space; the heat dissipation housing is an insulating housing without a ceramic layer; The top and bottom of the heat dissipation housing are both provided with hollow housings, the top of the chip contacts the hollow housings through the heat conductive layer, and the bottom of the chip contacts the hollow housings directly; A support layer is provided between the chip and the heat-conducting layer, and the area of ​​the support layer is smaller than the area of ​​the chip; the thickness of the heat-conducting layer is greater than or equal to 2 mm and less than or equal to 5 mm; The hollow shell is filled with a cooling medium for cooling the heat-conducting layer, and the cooling medium is an insulating fluid medium.

2. The power module according to claim 1, characterized in that: The difference between the thermal expansion coefficient of the chip and the thermal expansion coefficient of the heat conducting layer is less than or equal to 50%.

3. The power module according to claim 1 or 2, characterized in that: The material of the heat conducting layer is selected from at least one of copper, aluminum or diamond.

4. The power module according to any one of claims 1 to 3, characterized in that: The fluid medium includes cooling oil.

5. The power module according to any one of claims 1 to 4, characterized in that: The hollow shell is provided with an inlet and an outlet. The cooling medium flows into the interior of the hollow shell from the inlet and flows out from the outlet.

6. The power module according to claim 5, characterized in that: Heat dissipation teeth are provided in the hollow shell, and the cooling medium can flow through the gaps between the heat dissipation teeth.

7. The power module according to any one of claims 1 to 6, characterized in that: Heat dissipation teeth are provided on the outside of the hollow shell.

8. The power module according to any one of claims 1 to 7, characterized in that: The hollow shell includes a packaging plate and a cover plate. The packaging plate is arranged close to the chip, and the cover plate is arranged on a side of the packaging plate away from the chip.

9. The power module according to claim 8, characterized in that: A groove is provided on one side of the cover plate facing the packaging plate.

10. The power module according to claim 8, wherein: A groove is provided on one side of the packaging plate facing the cover plate.

11. An inverter, characterized in that: The inverter includes an auxiliary component and a power module according to any one of claims 1 to 10, wherein the auxiliary component is connected to the power module.

12. A vehicle, characterized in that: The invention comprises a power battery, an engine and the inverter according to claim 11, wherein the inverter is arranged between the power battery and the engine.

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