Power module and power conversion device
By using diamond thermal expansion plates and metal layer structures in the power module, combined with metal heat dissipation teeth and cooling channels, the problem of insufficient heat dissipation efficiency of copper-clad ceramic layers is solved, and efficient heat dissipation of the power module under high heat flux density is achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HUAWEI DIGITAL POWER TECH CO LTD
- Filing Date
- 2024-10-28
- Publication Date
- 2026-05-01
Smart Images
Figure CN121969142A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of electronic technology, and in particular to a power module and a power conversion device. Background Technology
[0002] To reduce global carbon emissions, new energy vehicles powered by electric motors have flourished in recent years. Onboard power modules are the core components for DC-AC conversion in electric vehicles. As the power consumption of automotive power module chips evolves at an accelerated pace, the heat flux density of future power module chips will gradually increase, potentially reaching 1000 watts per square centimeter.
[0003] Currently, most power modules use copper-clad ceramic layers as substrates. These layers provide thermal conductivity, electrical conductivity, and insulation, serving both as electrical connections to chips and heat dissipation aids. However, the copper-clad ceramic layer still exhibits a significant proportion of thermal resistance in the overall heat dissipation path of the power module. Therefore, improving the heat dissipation efficiency of power modules with high heat flux densities is a pressing issue. Summary of the Invention
[0004] This application provides a power module and a power conversion device to reduce the total thermal resistance of the heat dissipation path of the heat-generating devices in the power module, thereby improving the heat dissipation efficiency of the power module.
[0005] In a first aspect, this application provides a power module. The power module includes a thermally expanded plate, a first device, and a second device. A first metal layer and a second metal layer, spaced apart, are disposed on one side surface of the thermally expanded plate. The first metal layer and the second metal layer are disposed on the same layer. The first device is disposed on the side surface of the first metal layer facing away from the thermally expanded plate. The second device is disposed on the side surface of the second metal layer facing away from the thermally expanded plate. At least one of the first device and the second device is a heat-generating device. The thermally expanded plate includes diamond. The projection of the heat-generating device onto the thermally expanded plate along the thickness direction of the power module at least partially overlaps with the diamond-containing region of the thermally expanded plate.
[0006] In this design, the gap between the first and second metal layers can be formed by etching or other processes. The first device and the first metal layer, as well as the second device and the second metal layer, can be directly connected by sintering or welding, thereby achieving electrical connections between devices and metal layers, and between devices themselves. The thermal expansion plate contains diamond, and utilizing diamond's extremely high thermal conductivity, the thermal expansion plate can diffuse heat from the heat-generating device to the diamond-containing area of the thermal expansion plate. Thus, the thermal expansion plate can transfer heat from the heat-generating device along the thickness direction of the power module, and can also diffuse heat within the thermal expansion plate along a heat dissipation surface perpendicular to the thickness direction of the power module, achieving heat transfer and diffusion in both lateral and longitudinal directions. This reduces the total thermal resistance of the heat dissipation path of the heat-generating device, thereby improving the heat dissipation efficiency of the power module.
[0007] The aforementioned heat-expanding plate may include a pure diamond layer. Heat-expanding plates made of pure diamond are insulating, thus eliminating the need for an additional insulating layer on the other side of the plate, thereby simplifying the thermal path from the heat-generating device to the cooling medium and reducing thermal resistance.
[0008] A third metal layer is provided on the surface of the pure diamond layer facing away from the heating element. In this design, metal layers are provided on both sides of the pure diamond layer. Since the coefficients of thermal expansion of pure diamond and metal differ significantly, sandwiching the pure diamond layer between the metal layers can reduce the thermal deformation of the heat-expanding plate.
[0009] The aforementioned thermally expanded plate can also be a composite plate. Specifically, the thermally expanded plate includes a first hybrid layer and a second hybrid layer disposed on the same layer but spaced apart. Both the first and second hybrid layers are hybrid layers of diamond and metal. The first hybrid layer is disposed on the surface of the first metal layer facing away from the first device, and is spaced apart from the second metal layer. The second hybrid layer is disposed on the surface of the second metal layer facing away from the second device, and is spaced apart from the first metal layer. Because the first and second hybrid layers are conductive, they are spaced apart corresponding to the first and second metal layers to avoid short circuits between the first and second devices. In practical applications, the gap between the first and second metal layers can be connected to the gap between the first and second hybrid layers; that is, these two gaps can be formed together by etching or other processes.
[0010] The aforementioned heat-expanding plate also includes a ceramic layer and a third hybrid layer. The third hybrid layer is a mixture of diamond and metal. The ceramic layer is disposed on the surface of the first hybrid layer facing away from the first metal layer, and also on the surface of the second hybrid layer facing away from the second metal layer. The third hybrid layer is disposed on the surface of the ceramic layer facing away from the heating element. In this design, the ceramic layer can isolate and insulate the first and second hybrid layers from the third hybrid layer, respectively. Thus, both sides of the entire heat-expanding plate are mutually insulated, preventing the first and second devices from being short-circuited to the cooling medium.
[0011] The aforementioned thermal expansion plate has multiple metal heat dissipation fins on the side of its surface facing away from the heat-generating device. These metal heat dissipation fins increase the heat dissipation area, thereby transferring heat from the thermal expansion plate to the outside of the power module and improving heat dissipation efficiency.
[0012] In addition to using a ceramic layer to insulate the two sides of the heat-expanding plate from each other, the surface of the heat-expanding plate facing away from the heat-generating device can be covered with a thermally conductive insulating film.
[0013] In the scheme of this application, the thermal conductivity of the heat-expanding plate can be greater than or equal to 600W / mk, thereby improving the heat transfer and thermal performance of the heat-expanding plate and improving the heat dissipation efficiency.
[0014] The projection of the aforementioned heat-generating device onto the thermal expansion plate along the thickness direction of the power module lies within the region. Furthermore, the area of the diamond-bearing region of the thermal expansion plate perpendicular to the thickness direction of the power module can be greater than or equal to the area of the heat-generating device perpendicular to the thickness direction of the power module. Therefore, the heat-generating area of the heat-generating device can transfer heat entirely through the thermal expansion region of the thermal expansion plate, thereby increasing the heat dissipation area while reducing the amount of diamond used.
[0015] The area of the diamond-bearing region of the aforementioned heat-expanding plate perpendicular to the thickness direction of the power module is less than or equal to the area of the heat-expanding plate perpendicular to the thickness direction of the power module. In this solution, the parts of the heat-expanding plate that do not require heat expansion can be made of metal, while the areas that only require heat expansion use a material including diamond, thereby increasing the heat dissipation area while reducing the amount of diamond used.
[0016] The aforementioned power module also includes a packaging layer. This packaging layer is located on the side of the heat-generating device facing away from the thermal expansion plate, and it is used to encapsulate the thermal expansion plate, the first device, and the second device as a whole. In this design, the power module can be a packaged component, thereby making the overall structure of the power module more robust.
[0017] The aforementioned power module may also include a heat sink. The heat sink is located on the side of the thermal expansion plate away from the heat-generating device. In this design, the thermal expansion plate can transfer heat from the heat-generating device to the heat sink, thereby transferring the internal heat of the power module to the outside for heat dissipation.
[0018] The aforementioned radiator has cooling channels inside, and the cooling plate has openings that connect to the cooling channels. A thermal expansion plate covers the openings and is sealed to the cooling plate. That is, the thermal expansion plate can be used as part of the radiator, so the cooling medium can be in direct contact with the thermal expansion plate to shorten the heat dissipation path and allow the cooling medium to directly carry away the heat from the thermal expansion plate.
[0019] Secondly, this application provides a power conversion device. The power conversion device includes a circuit board and the power module described in the first aspect, with the power module connected to the circuit board. In this solution, the power module can achieve heat transfer and heat diffusion in both the lateral and longitudinal directions, thereby reducing the total thermal resistance of the heat dissipation path of the heat-generating device, thus improving the heat dissipation efficiency of the power module and consequently increasing the efficiency of the power conversion device. Attached Figure Description
[0020] Figure 1 An application scenario diagram of the power module provided in the embodiments of this application;
[0021] Figure 2 A schematic diagram of a power conversion device and a heat sink provided in an embodiment of this application;
[0022] Figure 3This is a schematic diagram of the structure of a power module provided in an embodiment of this application;
[0023] Figure 4 for Figure 3 A cross-sectional view of a medium-power module along the AA direction;
[0024] Figure 5 A schematic diagram of a power module and heat sink provided in an embodiment of this application;
[0025] Figure 6 This is another structural schematic diagram of the power module and heat sink provided in the embodiments of this application;
[0026] Figure 7 This is another structural schematic diagram of the power module and heat sink provided in the embodiments of this application;
[0027] Figure 8 This is another structural schematic diagram of the power module and heat sink provided in the embodiments of this application;
[0028] Figure 9 Another cross-sectional view of the power module provided in the embodiments of this application;
[0029] Figure 10 This is another structural schematic diagram of the power module and heat sink provided in the embodiments of this application;
[0030] Figure 11 This is another structural schematic diagram of the power module and heat sink provided in the embodiments of this application;
[0031] Figure 12 This is another structural schematic diagram of the power module and heat sink provided in the embodiments of this application;
[0032] Figure 13 Another cross-sectional view of the power module provided in the embodiments of this application;
[0033] Figure 14 This is another structural schematic diagram of the power module and heat sink provided in the embodiments of this application;
[0034] Figure 15 This is another structural schematic diagram of the power module and heat sink provided in the embodiments of this application;
[0035] Figure 16 Another cross-sectional view of the power module provided in the embodiments of this application;
[0036] Figure 17 This is another structural schematic diagram of the power module and heat sink provided in the embodiments of this application;
[0037] Figure 18This is another structural schematic diagram of the power module and heat sink provided in the embodiments of this application;
[0038] Figure 19 Another cross-sectional view of the power module provided in the embodiments of this application;
[0039] Figure 20 This is another structural schematic diagram of the power module and heat sink provided in the embodiments of this application;
[0040] Figure 21 This is another structural schematic diagram of the power module and heat sink provided in the embodiments of this application;
[0041] Figure 22 This is another structural schematic diagram of the power module and heat sink provided in the embodiments of this application;
[0042] Figure 23 This is another structural schematic diagram of the power module and heat sink provided in the embodiments of this application;
[0043] Figure 24 This is a schematic diagram of a heating device and a thermal expansion plate provided in an embodiment of this application.
[0044] Figure label:
[0045] 01-Power Conversion Device
[0046] 02-First Circuit Board
[0047] 10-Power Module
[0048] 11-Hot expanded plate
[0049] 12-First Device
[0050] 13-Second Device
[0051] 14-First Metal Layer
[0052] 15-Second Metal Layer
[0053] 16-gap
[0054] 17-Metallic bonding wire
[0055] 18-Radiator
[0056] 19-Cooling flow channel
[0057] 20-Metal heat dissipation fins
[0058] 21-Encapsulation layer
[0059] 22-Shell
[0060] 23-Third Metal Layer
[0061] 24-Thermal bonding material layer
[0062] 25-First Mixing Layer
[0063] 26-Second Mixing Layer
[0064] 27- Thermally conductive insulating film
[0065] 28-Ceramic Layer
[0066] 29-Third Mixed Layer Detailed Implementation
[0067] To make the objectives, technical solutions, and advantages of this application clearer, the application will now be described in further detail with reference to the accompanying drawings.
[0068] To facilitate understanding of the power module and power conversion device provided in the embodiments of this application, their application scenarios are described below. The power module can be applied to power conversion devices in scenarios such as photovoltaic power generation equipment, electric vehicles, and energy storage devices. In electric vehicles, the power module can be used for AC-DC conversion or DC conversion; for example, it can be applied to on-board chargers (OBCs) and motor control units (MCUs). Additionally, in photovoltaic power generation equipment, the power module can be applied to power conversion devices. Power conversion devices can convert the DC power generated by solar panels into AC power for external output. In energy storage devices, the power module can be used to convert external AC power into DC power for storage in the battery pack, or it can be used to convert the DC power output from the battery pack into AC power for output to AC loads.
[0069] Figure 1 This is an application scenario diagram of the power module provided in the embodiments of this application. Figure 2 This is a schematic diagram of a power conversion device and a heat sink provided in an embodiment of this application. Figure 1 and Figure 2As shown, in one embodiment, the MCU's power module can employ a water-cooled circulation. The heat sink 18 can have cooling channels. Specifically, the power conversion device 01 includes a first circuit board 02 and a power module 10, with the power module 10 connected to the first circuit board 02. The power module 10 can be connected to the cooling channels of the heat sink 18 and dissipate heat through the cooling medium within the cooling channels. These cooling channels can also be connected to components such as oil-water heat exchangers and water pumps to form a circulating cooling channel. The power module 10 includes a second circuit board and power devices such as power transistors and chips fixed on the second circuit board. The power devices are electrically connected to conductive lines in the second circuit board. During actual operation, the power devices generate significant heat; therefore, the power module 10 is in contact with the water-cooled heat sink 18 so that the heat sink 18 dissipates heat from the power module 10.
[0070] Current power modules use a copper-clad ceramic layer as the heat dissipation substrate, which is then bonded to a water-cooled heatsink. The copper-clad ceramic layer serves to conduct heat, conduct electricity, and insulate, enabling electrical connections between power devices and transferring heat from the power module's interior to the water-cooled heatsink. However, the copper-clad ceramic layer still exhibits a relatively large proportion of thermal resistance in the overall heat dissipation path of the power module.
[0071] In view of this, this application provides a power module and a power conversion device to reduce the total thermal resistance of the heat dissipation path of the heat-generating device in the power module, thereby improving the heat dissipation efficiency of the power module.
[0072] It should be noted that the terminology used in the following embodiments is for the purpose of describing specific embodiments only and is not intended to be a limitation of this application. As used in the specification and appended claims of this application, the singular expressions “a,” “an,” “the,” “the,” “the,” and “this” are intended to also include expressions such as “one or more,” unless the context clearly indicates otherwise.
[0073] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of 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 "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.
[0074] In this application, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "multiple" means two or more.
[0075] Furthermore, in this article, directional terms such as "top," "bottom," "upper," and "lower" are defined relative to the orientation of the structure as shown in the attached drawings. It should be understood that these directional terms are relative concepts, used for relative description and clarification, and can change accordingly depending on the orientation of the structure.
[0076] Figure 3 This is a schematic diagram of a power module provided in an embodiment of this application. Figure 4 for Figure 3 A cross-sectional view of a medium-power module along the AA direction. (Example) Figure 3 and Figure 4 As shown, the power module 10 of this application includes a thermally expanded plate 11 and multiple devices. Among these, at least a first device 12 and a second device 13 are included. In this embodiment, the power module 10 may include at least one of an IGBT module, a SiC module, and a GaN module. Taking an IGBT module as an example, an IGBT module is a modular semiconductor product packaged by bridging a series of chips, such as an IGBT chip and a freewheeling diode (FWD) chip, through a specific circuit. The packaged IGBT module can be directly applied to equipment such as frequency converters, uninterruptible power supplies (UPS), inverters, and powertrains. When the IGBT module is working, the aforementioned chips may become heat sources and generate heat, i.e., they are heat-generating devices. In the aforementioned power module 10, at least one of the first device 12 and the second device 13 is a heat-generating device.
[0077] The aforementioned components can be directly fabricated on the heat-expanding plate 11. The heat-expanding plate 11 has both electrical and thermal conductivity functions. For example... Figure 4 As shown, specifically, a first metal layer 14 and a second metal layer 15 are disposed on one side surface of the heat-expanded plate 11. The first metal layer 14 and the second metal layer 15 are spaced apart and disposed in the same layer. In this embodiment, the co-positioning of the first metal layer 14 and the second metal layer 15 can be achieved by etching the first metal layer 14 and the second metal layer 15 onto a single metal layer, or it can be achieved by fabricating the first metal layer 14 and the second metal layer 15 separately in the same process step; no specific limitation is imposed here.
[0078] Please continue reading. Figure 4 The first device 12 can be disposed on the surface of the first metal layer 14 facing away from the heat-expanding plate 11. The second device 13 can be disposed on the surface of the second metal layer 15 facing away from the heat-expanding plate 11. In practical applications, the first device 12 and the first metal layer 14 can be directly connected through processes such as sintering or welding, thereby achieving an electrical connection between the first device 12 and the first metal layer 14. Similarly, the second device 13 and the second metal layer 15 can be directly connected through processes such as sintering or welding, thereby achieving an electrical connection between the second device 13 and the second metal layer 15. The spacing between the first metal layer 14 and the second metal layer 15 can prevent short circuits between the first device 12 and the second device 13. That is, there is a gap 16 between the first metal layer 14 and the second metal layer 15, which makes the first metal layer 14 and the second metal layer 15 insulated from each other. In some circuits, the devices located on both sides of the gap 16 may need to be electrically connected. Therefore, a metal bonding wire 17 may be provided on the side of the multiple devices away from the thermal expansion plate 11. The metal bonding wire 17 can electrically connect the devices on both sides of the gap 16.
[0079] In the power module 10 described above, the heat spreader 11 is used to diffuse the heat from the heat-generating device to the side of the heat spreader 11 away from the heat-generating device. The following example uses the first device 12 and the second device 13 as both being heat-generating devices.
[0080] Specifically, the heat-expanding plate 11 includes diamond. The heating element is located on the heat-expanding plate 11 along the thickness direction of the power module 10 (e.g., Figure 4 The projection of the heat spreader (in the vertical direction) at least partially overlaps with the diamond-containing region of the heat spreader 11. Therefore, utilizing the extremely high thermal conductivity of diamond, the heat spreader 11 can diffuse the heat transferred from the heat-generating device to the diamond-containing heat dissipation surface. In this way, the heat spreader 11 can transfer heat from the heat-generating device along the thickness direction of the power module 10, and can also diffuse heat within the heat spreader 11 along the heat dissipation surface perpendicular to the thickness direction of the power module 10, thereby achieving heat transfer and diffusion in both the lateral and longitudinal directions. This reduces the total thermal resistance of the heat dissipation path of the heat-generating device, thereby improving the heat dissipation efficiency of the power module 10.
[0081] In practical applications, the thermal expansion plate 11 is used to transfer heat from the heat-generating device to the heat sink 18. The heat sink 18 can be a water-cooled heat sink, a two-phase heat sink, or a cooling plate, etc. The heat sink 18 has cooling channels 19 inside, which contain a cooling medium. Through the flow of the cooling medium, the cooling medium can carry away the heat from the surface of the thermal expansion plate 11, thereby achieving heat dissipation for the power module 10.
[0082] like Figure 4As shown, in some embodiments, the heat-expanding plate 11 may include a pure diamond layer. The heat-expanding plate 11, made of pure diamond, is insulating; therefore, no additional insulating layer is needed on the other side of the heat-expanding plate 11, thereby simplifying the thermal path from the heating device to the cooling medium and reducing thermal resistance. In practical applications, diamond has extremely high thermal conductivity, and the pure diamond layer can diffuse the heat transferred from the heating device throughout the entire pure diamond layer.
[0083] Figure 5 This is a schematic diagram of a power module and heat sink provided in an embodiment of this application. Figure 4 and Figure 5 As shown, in some embodiments, the pure diamond layer can form a cooling channel 19 together with the housing 22 of the heat sink 18, meaning that the cooling medium can directly contact the surface of the heat expansion plate 11. In this embodiment, since the pure diamond layer is insulating, water or an insulating medium can be used as the cooling medium.
[0084] Figure 6 This is another structural schematic diagram of the power module and heat sink provided in an embodiment of this application. (See attached diagram.) Figure 6 As shown, to improve heat dissipation efficiency, multiple metal heat dissipation teeth 20 can be provided on the surface of the pure diamond layer facing away from the heat-generating device. These metal heat dissipation teeth 20 can increase the contact area between the pure diamond layer and the cooling medium, thereby accelerating the removal of heat by the cooling medium.
[0085] Figure 7 This is another structural schematic diagram of the power module and heat sink provided in an embodiment of this application. (See attached diagram.) Figure 7 As shown, in some embodiments, the housing 22 of the heat sink 18 can independently form a cooling channel 19, with a pure diamond layer bonded to the housing 22 of the heat sink 18. In this embodiment, the power module 10 and the heat sink 18 can be fabricated separately, and then the thermal expansion plate 11 is connected to the housing 22 of the heat sink 18 to form an integrated structure of the power module 10 and the heat sink 18. Alternatively, the heat sink 18 can be fabricated first, and then a pure diamond layer can be fabricated on the housing 22 of the heat sink 18, followed by the fabrication of a first metal layer 14, a second metal layer 15, and multiple components to form an integrated structure of the power module 10 and the heat sink 18. In addition, multiple metal heat dissipation teeth 20 can be provided inside the heat sink 18 to increase the contact area between the inner wall of the cooling channel 19 and the cooling medium, thereby improving the heat dissipation efficiency of the cooling medium. Since the heat sink 18 independently forms the cooling channel 19, water or an insulating medium can be used as the cooling medium.
[0086] like Figure 7As shown in the embodiments of this application, 10 may further include an encapsulation layer 21. The encapsulation layer 21 is located on the side of the plurality of devices facing away from the thermal expansion plate 11. The encapsulation layer 21 is used to encapsulate the plurality of devices and the thermal expansion plate 11 as a whole, thereby making the structure of the entire power module 10 more robust. This application does not limit the encapsulation design and process.
[0087] Figure 8 This is another structural schematic diagram of the power module and heat sink provided in an embodiment of this application. (See attached diagram.) Figure 8 As shown, in another embodiment, the encapsulation layer 21 can also encapsulate a portion of the housing 22 of the heat sink 18 together with the thermal expansion plate 11, thereby making the connection between the power module 10 and the heat sink 18 more secure.
[0088] like Figures 5 to 8 As shown, the cooling medium flows within the cooling channel 19, specifically in a direction parallel to the thermal expansion plate 11 (e.g., Figures 5 to 8 The flow can be horizontal (in the direction of the heat expansion plate 11), or it can flow toward the heat expansion plate 11 in a direction perpendicular to the plane of the heat expansion plate 11 (e.g., horizontal direction). Figures 5 to 8 (The vertical upward direction in the middle), there is no restriction here.
[0089] Figure 9 Another cross-sectional view of the power module provided in an embodiment of this application. (See attached image) Figure 9 As shown, a third metal layer 23 can also be disposed on the surface of the pure diamond layer facing away from the heating device. That is, metal layers are disposed on both sides of the pure diamond layer. Since the coefficients of thermal expansion of pure diamond and metal differ significantly, the deformation of pure diamond differs from that of metal when heated. In this embodiment, the pure diamond layer is sandwiched between the metal layers, which can reduce the thermal deformation of the heat expansion plate 11.
[0090] Figure 10 This is another structural schematic diagram of the power module and heat sink provided in an embodiment of this application. (See attached diagram.) Figure 10 As shown, the aforementioned heat-expanding plate 11 can form a cooling channel 19 together with the housing 22 of the radiator 18. Specifically, the surface of the third metal layer 23 can be welded to multiple metal heat dissipation teeth 20, or multiple metal heat dissipation teeth 20 can be directly grown on the surface of the third metal layer 23, and the third metal layer 23 is welded to the housing 22 of the radiator 18 to form the cooling channel 19. Since the pure diamond layer has insulating properties, water or an insulating medium can be used as the cooling medium.
[0091] Figure 11 This is a schematic diagram of another structure of the power module and heat sink provided in an embodiment of this application. Figure 12 This is another structural schematic diagram of the power module and heat sink provided in an embodiment of this application. (See attached diagram.) Figure 11 and Figure 12As shown, the housing 22 of the radiator 18 can independently form cooling channels 19, and the third metal layer 23 is attached to the housing 22 of the radiator 18. In this embodiment, the surface of the third metal layer 23 can be connected to the housing 22 of the radiator 18 by sintering or welding (a thermal bonding material layer 24 may be formed between the third metal layer 23 and the housing 22) to connect them together. Since the radiator 18 independently forms cooling channels 19, water or an insulating medium can be selected as the cooling medium.
[0092] In the power module 10 of this application, the thermally expanded plate 11 can also be a diamond composite plate. Figure 13 Another cross-sectional view of the power module provided in an embodiment of this application. (See attached image) Figure 13 As shown, the thermal expansion plate 11 includes a first hybrid layer 25 and a second hybrid layer 26. Both the first hybrid layer 25 and the second hybrid layer 26 are hybrid layers of diamond and metal. Since the first hybrid layer 25 and the second hybrid layer 26 are conductive, they are spaced apart from the first metal layer 14 and the second metal layer 15 to avoid short circuits between the first device 12 and the second device 13. Specifically, the first hybrid layer 25 and the second hybrid layer 26 are disposed in the same layer. The first hybrid layer 25 is disposed on the surface of the first metal layer 14 facing away from the first device 12, and the first hybrid layer 25 is spaced apart from the second metal layer 15. The second hybrid layer 26 is disposed on the surface of the second metal layer 15 facing away from the second device 13, and the second hybrid layer 26 is spaced apart from the first metal layer 14. In practical applications, the gap 16 between the first metal layer 14 and the second metal layer 15 can be connected to the gap between the first hybrid layer 25 and the second hybrid layer 26; that is, these two gaps can be formed together by etching or other processes.
[0093] It should be noted that the hybrid layer in this application includes diamond and metal, meaning that the materials used to make the hybrid layer include diamond and metal. In one embodiment, diamond and metal can form a diamond / metal matrix composite material, and the entire hybrid layer is made using this composite material. In another embodiment, a portion of the hybrid layer is made of diamond, and another portion is made of metal. The diamond portion and the metal portion of the hybrid layer can be integrally molded to form the entire hybrid layer; alternatively, the diamond portion and the metal portion of the hybrid layer can be molded separately and then processed into an integral structure to form the entire hybrid layer. In another embodiment, the hybrid layer can also be made using the methods described in the two embodiments above.
[0094] Figure 14 This is a schematic diagram of another structure of the power module and heat sink provided in an embodiment of this application. Figure 15 This is another structural schematic diagram of the power module and heat sink provided in an embodiment of this application. (See attached diagram.) Figure 14 and Figure 15As shown, the aforementioned heat-expanding plate 11 can form a cooling channel 19 together with the housing 22 of the radiator 18. Specifically, the surfaces of the first mixing layer 25 and the second mixing layer 26 can be welded to the housing 22 of the radiator 18 to form the cooling channel 19. Since the first mixing layer 25 and the second mixing layer 26 are conductive, an insulating working medium can be selected as the cooling medium.
[0095] Figure 16 Another cross-sectional view of the power module provided in an embodiment of this application. (See attached image) Figure 16 As shown, to insulate the two sides of the heat-expanding plate 11 from each other, the surface of the heat-expanding plate 11 facing away from the heat-generating device can be covered with a thermally conductive insulating film 27. That is, the thermally conductive insulating film 27 covers the first hybrid layer 25 and the second hybrid layer 26. The thermally conductive insulating film 27 can isolate and insulate the first hybrid layer 25 and the second hybrid layer 26 from the heat sink 18, respectively. In this application, the thermally conductive insulating film 27 may include a ceramic film, a silicone grease film, or an organic material film. Furthermore, the thickness of the thermally conductive insulating film 27 may be less than or equal to 160 micrometers.
[0096] Figure 17 This is a schematic diagram of another structure of the power module and heat sink provided in an embodiment of this application. Figure 18 This is another structural schematic diagram of the power module and heat sink provided in an embodiment of this application. (See attached diagram.) Figure 17 and Figure 18 As shown, the power module 10 can be attached to the housing 22 of the heat sink 18. The housing 22 of the heat sink 18 can independently form a cooling channel 19, and the thermally conductive insulating film 27 is attached to the housing 22 of the heat sink 18. Since the heat sink 18 independently forms a cooling channel 19, water or an insulating medium can be selected as the cooling medium.
[0097] Figure 19 Another cross-sectional view of the power module provided in an embodiment of this application. (See attached image) Figure 19As shown, in addition to using a thermally conductive insulating film 27 to insulate the two sides of the heat-expanding plate 11 from each other, in another embodiment, the heat-expanding plate 11 also includes a ceramic layer 28 and a third hybrid layer 29. The third hybrid layer 29 is a hybrid layer of diamond and metal. The ceramic layer 28 is disposed on the surface of the first hybrid layer 25 facing away from the first metal layer 14, and the ceramic layer 28 is disposed on the surface of the second hybrid layer 26 facing away from the second metal layer 15. The third hybrid layer 29 is disposed on the surface of the ceramic layer 28 facing away from the heating device. Therefore, the first device 12, the first metal layer 14, the ceramic layer 28, and the third hybrid layer 29 are arranged sequentially along the thickness direction of the power module 10, and the second device 13, the second metal layer 15, the ceramic layer 28, and the third hybrid layer 29 are arranged sequentially along the thickness direction of the power module 10. In this embodiment, the ceramic layer 28 can isolate and insulate the first hybrid layer 25 and the second hybrid layer 26 from the third hybrid layer 29, respectively. In this way, both sides of the entire thermal expansion plate 11 are mutually insulated to prevent the first device 12 and the second device 13 from being short-circuited to the cooling medium. Furthermore, the thickness of the ceramic layer 28 can be less than or equal to 350 micrometers.
[0098] Figure 20 This is a schematic diagram of another structure of the power module and heat sink provided in an embodiment of this application. Figure 21 This is another structural schematic diagram of the power module and heat sink provided in an embodiment of this application. (See attached diagram.) Figure 20 and Figure 21 As shown, the aforementioned heat-expanding plate 11 can form a cooling channel 19 together with the housing 22 of the radiator 18. Specifically, the surface of the third mixing layer 29 can be welded to the housing 22 of the radiator 18 to form the cooling channel 19. Since the ceramic layer 28 insulates the first mixing layer 25 and the second mixing layer 26 from the third mixing layer 29 respectively, water or an insulating medium can be used as the cooling medium.
[0099] Figure 22 This is a schematic diagram of another structure of the power module and heat sink provided in an embodiment of this application. Figure 23 This is another structural schematic diagram of the power module and heat sink provided in an embodiment of this application. (See attached diagram.) Figure 22 and Figure 23 As shown, the power module 10 can also be attached to the housing 22 of the heat sink 18. The housing 22 of the heat sink 18 can independently form cooling channels 19, and the third hybrid layer 29 is attached to the housing 22 of the heat sink 18. Specifically, the surface of the third hybrid layer 29 can be connected to the housing 22 of the heat sink 18 by sintering or welding (a thermal bonding material layer 24 may be formed between the third hybrid layer 29 and the housing 22). Since the heat sink 18 independently forms cooling channels 19, water or an insulating medium can be used as the cooling medium.
[0100] like Figure 22As shown, in one embodiment, the encapsulation layer 21 of the power module 10 can encapsulate multiple devices and the thermal expansion plate 11 as a whole, thereby making the structure of the entire power module 10 more robust. Figure 23 As shown, in another embodiment, the encapsulation layer 21 can also encapsulate a portion of the housing 22 of the heat sink 18 together with the thermal expansion plate 11, thereby making the connection between the power module 10 and the heat sink 18 more secure.
[0101] In the embodiments of this application, the thermal conductivity of the heat-expanding plate 11 can be set to be greater than or equal to 600 W / mK, thereby improving the heat transfer and heat expansion performance of the heat-expanding plate 11 and enhancing heat dissipation efficiency. When the heat-expanding plate 11 is a pure diamond layer, since the thermal conductivity of diamond itself is typically between 2000 W / mK and 2200 W / mK, the thermal conductivity of the heat-expanding plate 11 can be much greater than 600 W / mK. When the heat-expanding plate 11 is a hybrid plate, the thermal conductivity of the hybrid layer can be made greater than or equal to 600 W / mK by adjusting the diamond content.
[0102] Figure 24 This is a schematic diagram of a heating device and a thermal expansion plate provided in an embodiment of this application. Figure 24 As shown, the projection of the heat-generating device onto the heat-expanding plate 11 along the thickness direction of the power module 10 lies within the diamond-bearing region of the heat-expanding plate 11. The area S2 of the diamond-bearing region of the heat-expanding plate 11 perpendicular to the thickness direction of the power module 10 can be greater than or equal to the area S1 of the heat-generating device perpendicular to the thickness direction of the power module 10. Therefore, the heat-generating area of the heat-generating device can completely transfer heat through the heat-expanding region of the heat-expanding plate 11, thereby increasing the heat dissipation area while reducing the amount of diamond used.
[0103] Furthermore, the area S2 of the diamond-bearing region of the heat-expanding plate 11 perpendicular to the thickness direction of the power module 10 is less than or equal to the area S3 of the heat-expanding plate 11 perpendicular to the thickness direction of the power module 10. In this embodiment, the portion of the heat-expanding plate 11 that does not require heat expansion can be made of metal, while the portion requiring heat expansion is made of a material including diamond. This increases the heat dissipation area while reducing the amount of diamond used, thereby reducing the manufacturing cost of the heat-expanding plate 11. Specifically, the portion of the heat-expanding plate 11 located in the aforementioned region can be a pure diamond layer, or the portion of the heat-expanding plate 11 located in the aforementioned region can be a hybrid layer.
[0104] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.
Claims
1. A power module, characterized in that, Includes a thermally expanded plate, a first device, and a second device, wherein: One side surface of the heat-expanding plate is provided with a first metal layer and a second metal layer spaced apart, and the first metal layer and the second metal layer are disposed in the same layer. The first device is disposed on the surface of the first metal layer opposite to the heat-expanding plate, and the second device is disposed on the surface of the second metal layer opposite to the heat-expanding plate; at least one of the first device and the second device is a heating device. The heat-expanding plate includes diamond; the projection of the heating device onto the heat-expanding plate along the thickness direction of the power module at least partially overlaps with the area of the heat-expanding plate containing the diamond.
2. The power module as described in claim 1, characterized in that, The heat-expanded plate comprises a pure diamond layer.
3. The power module as described in claim 2, characterized in that, A third metal layer is provided on the side of the pure diamond layer facing away from the heating device.
4. The power module as described in claim 1, characterized in that, The heat-expanding plate includes a first mixed layer and a second mixed layer that are arranged in the same layer but spaced apart. Both the first mixed layer and the second mixed layer are mixed layers of diamond and metal. The first hybrid layer is disposed on the side surface of the first metal layer opposite to the first device, and the first hybrid layer is spaced apart from the second metal layer; the second hybrid layer is disposed on the side surface of the second metal layer opposite to the second device, and the second hybrid layer is spaced apart from the first metal layer.
5. The power module as described in claim 4, characterized in that, The thermally expanded plate further includes a ceramic layer and a third hybrid layer, wherein the third hybrid layer is a mixture of diamond and metal; the ceramic layer is disposed on the side surface of the first hybrid layer opposite to the first metal layer, and the ceramic layer is disposed on the side surface of the second hybrid layer opposite to the second metal layer; The third hybrid layer is disposed on the surface of the ceramic layer opposite to the heating device.
6. The power module as described in any one of claims 2 to 5, characterized in that, The heat-expanding plate has multiple metal heat dissipation teeth on the side surface opposite to the heat-generating device.
7. The power module as described in claim 4, characterized in that, The surface of the heat-expanding plate opposite to the heating device is covered with a thermally conductive insulating film.
8. The power module as described in any one of claims 1 to 7, characterized in that, The thermal conductivity of the heat-expanding plate is greater than or equal to 600 W / mk.
9. The power module as described in any one of claims 1 to 8, characterized in that, The projection of the heating element onto the heat-expanding plate along the thickness direction of the power module is located within the region, and the area of the region perpendicular to the thickness direction of the power module is greater than or equal to the area of the heating element perpendicular to the thickness direction of the power module.
10. The power module as described in claim 9, characterized in that, The area of the region perpendicular to the thickness direction of the power module is less than or equal to the area of the thermally expanded plate perpendicular to the thickness direction of the power module.
11. The power module as described in any one of claims 1 to 10, characterized in that, The power module further includes an encapsulation layer located on the side of the heating device away from the thermal expansion plate. The encapsulation layer is used to encapsulate the thermal expansion plate, the first device, and the second device as a whole.
12. The power module as described in any one of claims 1 to 11, characterized in that, The power module also includes a heat sink, which is located on the side of the thermal expansion plate away from the heat-generating device.
13. The power module as described in claim 12, characterized in that, The radiator has a cooling channel inside, and the cooling plate has an opening that connects to the cooling channel; the heat expansion plate covers the opening and is sealed to the cooling plate.
14. A power conversion device, characterized in that, It includes a circuit board and a power module as described in any one of claims 1 to 13, wherein the power module is connected to the circuit board.