Power module and power equipment

Abstract

The invention relates to the technical field of electronic equipment, and provides a power module and power device.The power module comprises a power device, a radiator and a thermal interface material layer, the thermal interface material layer comprises a directional heat conduction layer, and the directional heat conduction layer is arranged between the power device and the radiator and is in heat conduction connection with the power device and the radiator; the directional heat conduction layer comprises a first surface and a second surface, the first surface faces the power device, and the second surface deviates from the power device; the directional heat-conducting layer is provided with a plurality of heat-conducting fins, the plurality of heat-conducting fins are arranged at intervals along the first direction, and each heat-conducting fin extends from the first surface to the second surface; the first direction is parallel to the first surface; and the thermal resistance of the directional heat conduction layer is lower than that of the silicone grease. According to the power module and the power equipment, the heat dissipation efficiency of the power device can be higher, and the power module can better meet the requirements of integrated, miniaturized and high-power power equipment.

Description

Technical Field

[0001] The present application relates to the technical field of electronic equipment, and in particular to a power module and a power device. Background Art

[0002] With the development of science and technology, power devices are moving towards integration, miniaturization and high power, which leads to a significant increase in the heat generated per unit area of ​​power modules in power devices. This makes the heat dissipation requirements of power modules higher and higher, while the heat dissipation architecture of power modules in the existing technology can no longer meet the increasingly high heat dissipation requirements of power modules. Summary of the invention

[0003] The embodiments of the present application provide a power module and a power device to meet the increasingly improved heat dissipation requirements of the power module.

[0004] In the first aspect, the present application provides a power module including a power device, a heat sink and a thermal interface material layer, wherein the thermal interface material layer includes a directional heat conduction layer, which is arranged between the power device and the heat sink and is thermally connected to both the power device and the heat sink. The directional heat conduction layer includes a first surface and a second surface, the first surface faces the power device, and the second surface faces away from the power device. The directional heat conduction layer has a plurality of heat conduction sheets, which are arranged at intervals along a first direction, and each heat conduction sheet extends from the first surface to the second surface. The first direction is parallel to the first surface. The thermal resistance of the directional heat conduction layer is lower than the thermal resistance of silicone grease. In this solution, the plurality of heat conduction sheets of the directional heat conduction layer can form a plurality of continuous heat conduction paths between the power device and the heat sink, strengthen the conduction of heat from the power device to the heat sink, and thus help improve the heat dissipation efficiency of the power module. At the same time, the thermal resistance of the directional heat conduction layer is less than the thermal resistance of silicone grease, so compared with the case where silicone grease is used as the thermal interface material layer, the heat dissipation efficiency of the power device can be higher, so that the power module provided by the present application can be more suitable for integrated, miniaturized and high-power power devices.

[0005] In a possible embodiment, the directional heat conducting layer includes a vertical graphene heat conducting film. The directional heat conducting layer including the vertical graphene heat conducting film is beneficial to improving the rapid transfer of heat from the power device to the heat sink. In addition, each heat conducting sheet of the vertical graphene heat conducting film extends from the first surface to the second surface and is in a compressed state in the power module, and the shape of the longitudinal section of each heat conducting sheet is a curved structure, such as: "bow" type, "Z" type or "S" type. This makes the vertical graphene heat conducting film have a high rebound rate and a high compression rate, which can absorb the deformation of the power device and the heat sink caused by temperature change, and has a more stable thermal resistance and better high and low temperature stability.

[0006] In another possible embodiment, the directional heat conducting layer includes a vertical boron nitride thermal conductive insulating film. Each heat conducting sheet of the vertical boron nitride thermal conductive film extends from the first surface to the second surface and is in a compressed state in the power module. The shape of the longitudinal section of each heat conducting sheet is a curved structure, such as a "bow" type, a "Z" type or an "S" type, etc. This enables the vertical boron nitride thermal conductive film to have a high resilience and high compression rate, and can absorb the deformation of power devices and heat sinks caused by temperature changes, and has more stable thermal resistance and better high and low temperature stability. In addition, the vertical boron nitride thermal conductive film has insulating properties, so there is no need to set an insulating layer on the periphery of the vertical boron nitride thermal conductive film, which is conducive to simplifying the structure of the power module and improving the assembly efficiency of the power module.

[0007] In a possible embodiment, the power module includes a covering layer, and the thermal resistance of the covering layer is less than or equal to the thermal resistance of the silicone grease. The covering layer has a certain wettability, which can further reduce the interface contact thermal resistance between the vertical graphene thermal conductive film and the adjacent components. Furthermore, the power module satisfies at least one of the following conditions:

[0008] The power module includes a covering layer, which is arranged on a surface of the graphene thermal conductive film perpendicular to the power device. Or,

[0009] The power module includes a covering layer, which is arranged on a surface of the vertical graphene thermal conductive film away from the power device. Or,

[0010] The power module comprises two covering layers, one of the two covering layers is arranged on a surface of the vertical graphene heat conductive film facing the power device, and the other of the two covering layers is arranged on a surface of the vertical graphene heat conductive film facing away from the power device.

[0011] In a possible embodiment, the covering layer includes at least one of a first liquid metal layer, a phase-change thermal conductive material layer, a thermal conductive silicone grease layer, a thermal conductive silver paste layer, and a welding material layer.

[0012] Another power module provided by the present application includes a power device, a heat sink and a thermal interface material layer, wherein the thermal interface material layer is disposed between the power device and the heat sink and is thermally connected to both the power device and the heat sink; the thermal interface material layer includes a second liquid metal layer, and the thermal resistance of the second liquid metal layer is lower than the thermal resistance of silicone grease. In this solution, the thermal resistance of the second liquid metal layer is lower than the thermal resistance of silicone grease, so compared with the case where silicone grease is used as the thermal interface material layer, the heat dissipation efficiency of the power device can be higher, thereby making the power module provided by the present application more suitable for integrated, miniaturized and high-power power devices.

[0013] In a possible embodiment, the orthographic projection of the power device on the heat sink covers the orthographic projection of the thermal interface material layer on the heat sink, so that the entire thermal interface material layer can be used for heat dissipation of the power device, thereby improving the utilization rate of the thermal interface material layer.

[0014] In a possible embodiment, the power device includes a power chip and a plastic package, and the power chip is plastic-sealed in the plastic package. The orthographic projection of the thermal interface material layer on the heat sink covers the orthographic projection of the power chip on the heat sink. The power chip is the main heat-generating part of the power device, and the orthographic projection of the thermal interface material layer on the heat sink covers the orthographic projection of the power chip on the heat sink, so that the contact area between the thermal interface material layer and the power chip is larger, which is more conducive to efficient heat dissipation of the power chip.

[0015] In a possible embodiment, the power module includes an insulating member, which is ring-shaped. The thermal interface material layer is located in the middle of the ring formed by the insulating member to prevent debris falling from the edge of the vertical graphene thermal conductive film from causing a short circuit in surrounding electronic components, thereby playing a role of insulation protection.

[0016] In a possible embodiment, the insulating member includes at least one of an insulating adhesive, a sealing insulating foam, a sealing insulating curing adhesive, a thermally conductive insulating sheet, and an insulating silicone pad. It is worth noting that when the insulating member is an insulating adhesive, the insulating adhesive is used to provide both insulation protection and a fixed connection between two adjacent parts.

[0017] In a possible embodiment, the power device includes a main body and a terminal, the main body includes a top surface, a bottom surface and a side surface, the top surface and the bottom surface are parallel to the thermal interface material layer, and the side surface connects the top surface and the bottom surface. The terminal is located on the side of the main body and is electrically connected to the main body. The power module includes an insulating ring, which is located on the periphery of the insulating member and surrounds the insulating member. The orthographic projection of the terminal on the heat sink at least partially overlaps with the orthographic projection of the insulating ring on the heat sink. The heat sink is usually a metal structure with conductivity. The terminal of the power device is separated from the heat sink by the insulating ring, which can ensure good insulation between the terminal and the heat sink.

[0018] In a possible embodiment, the power module includes a housing having a housing cavity, the power device is located in the housing cavity, and the heat sink is located outside the housing cavity. The housing includes a plate body, which is arranged on a side of the thermal interface material layer facing the power device, or on a side of the thermal interface material layer facing away from the power device.

[0019] In a possible embodiment, the heat sink includes a first heat sink and a second heat sink, and the thermal interface material layer includes a first thermal interface material layer and a second thermal interface material layer. The first thermal interface material layer and the second thermal interface material layer are respectively arranged on opposite sides of the power device, the first heat sink is arranged on the side of the first thermal interface material layer away from the power device, and the second heat sink is arranged on the side of the second thermal interface material layer away from the power device. In other words, the power module has a double-sided heat dissipation structure. In this solution, heat dissipation structures are arranged on both sides of the power device, so the heat dissipation effect of the power device is better.

[0020] In a possible embodiment, the power module further includes a cover plate, which is arranged on a side of the power device away from the heat sink. The cover plate includes a fixing device, the orthographic projection of the fixing device on the heat sink does not intersect with the orthographic projection of the thermal interface material layer on the heat sink, and the cover plate is fixedly connected to the heat sink through the fixing device.

[0021] In a second aspect, an embodiment of the present application provides a power device, which includes a circuit board and a power module provided by the technical solution of the first aspect, and the power module is electrically connected to the circuit board. The power device can at least achieve the technical effect that can be achieved by the power module provided by the technical solution of the first aspect, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of the structure of a power module provided in this application;

[0023] Figure 2 A schematic diagram of the structure of another power module provided in this application;

[0024] Figure 3 A schematic diagram of the structure of a directional heat conduction layer in a power module provided in the present application;

[0025] Figure 4 A schematic diagram of the structure of another power module provided in this application;

[0026] Figure 5 A schematic diagram of the structure of another power module provided in this application;

[0027] Figure 6 A schematic diagram of the structure of another power module provided in this application;

[0028] Figure 7 A schematic diagram of the structure of another power module provided in this application;

[0029] Figure 8 A schematic diagram of the structure of another power module provided in this application;

[0030] Fig. 9A schematic diagram of the structure of another power module provided in this application;

[0031] Fig.10 A schematic diagram of the structure of another power module provided in this application;

[0032] Fig.11 A schematic diagram of the structure of another power module provided in this application;

[0033] Fig.12 for Fig.11 Exploded view of the power module shown. DETAILED DESCRIPTION

[0034] Power modules are widely used in servo motors, frequency converters, inverters and other fields. Specifically, power modules include heat sinks and power devices. A silicone grease layer is fixed between the power device and the heat sink to improve the heat dissipation efficiency of the power device. However, as power devices develop towards integration, miniaturization and high power, the current heat dissipation architecture of power modules is difficult to meet the heat dissipation requirements of power modules due to the thermal resistance of silicone grease itself and the stability of thermal resistance after long-term use.

[0035] Based on this, the embodiment of the present application provides a power module and a power device to solve the above problems. In order to make the purpose, technical solution and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings.

[0036] The terms used in the following embodiments are only for the purpose of describing specific embodiments and are not intended to be limiting of the present application. As used in the specification and appended claims of the present application, the singular expressions "a", "an", "said", "above", "the" and "this" are intended to also include expressions such as "one or more", unless there is a clear contrary indication in the context.

[0037] References to "one embodiment" or "some embodiments" etc. described in this specification mean that a particular feature, structure or characteristic described in conjunction with the embodiment is included in one or more embodiments of the present application. Thus, the phrases "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear at different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0038] Figure 1 A schematic diagram of the structure of a power module provided in an embodiment of the present application. Figure 1As shown, the power module includes a power device 1, a heat sink 2 and a thermal interface material layer. The power device 1 is opposite to the heat sink 2. The thermal interface material layer is arranged between the power device 1 and the heat sink 2, and is thermally connected to both the power device 1 and the heat sink 2. That is to say, one surface of the thermal interface material layer faces the power device 1, and the other surface of the thermal interface material layer faces away from the power device 1, and the thermal interface material layer can conduct heat to the heat sink 2 and the power device 1. It should be understood that in a specific implementation, the number of power devices 1 in the power module is set according to actual needs. Exemplarily, the power device 1 can be one or more, for example: two, three or four. It is worth noting that when the number of power devices 1 is multiple, multiple power devices 1 can correspond to the same thermal interface material layer, that is, the multiple power devices 1 are thermally connected to the heat sink 2 through the same thermal interface material layer. As Figure 2 As shown, when there are multiple power devices 1, each power device 1 may also correspond to a thermal interface material layer, that is, the power module includes multiple pairs of power devices 1 and thermal interface material layers, and each power device 1 is thermally connected to the heat sink 2 through the corresponding thermal interface material layer. Of course, in some embodiments, when there are multiple power devices 1, a part of the power devices 1 may correspond to the same thermal interface material layer, and the part of the power devices 1 may be thermally connected to the heat sink 2 through the same thermal interface material layer. The remaining power devices 1 each correspond to a thermal interface material layer, and each power device 1 is thermally connected to the heat sink 2 through the corresponding thermal interface material layer. Next, this application mainly takes the case where one power device 1 corresponds to one thermal interface material layer as an example. Specifically, please continue to refer to Figure 1 , the thermal interface material layer includes a directional heat conducting layer 3 having a thermal resistance lower than that of silicone grease, and the directional heat conducting layer 3 includes a first surface 3a and a second surface 3b, the first surface 3a faces the power device 1, and the second surface 3b faces away from the power device 1. Further, the directional heat conducting layer 3 has a plurality of heat conducting sheets 31, which are arranged at intervals along a first direction A parallel to the first surface 3a, and each heat conducting sheet 31 extends from the first surface 3a to the second surface 3b. In this scheme, the plurality of heat conducting sheets 31 of the directional heat conducting layer 3 can form a plurality of continuous heat conducting paths between the power device 1 and the heat sink 2, strengthen the conduction of heat from the power device 1 to the heat sink 2, and thus help to improve the heat dissipation efficiency of the power module. At the same time, the thermal resistance of the directional heat conducting layer 3 is less than that of the silicone grease, so compared with the case where the silicone grease is used as the thermal interface material layer, the heat dissipation efficiency of the power device 1 can be made higher, so that the power module provided in this application can be more suitable for integrated, miniaturized and high-power power equipment.

[0039] For ease of description, a cross section of the heat conducting sheet 31 on a plane parallel to the first direction A and perpendicular to the first surface 3a (ie, Figure 1The cross section shown in ( ) is the longitudinal cross section of the heat conducting sheet 31. The shape of the longitudinal cross section of each heat conducting sheet 31 is not limited in the present application. For example, the longitudinal cross section of each heat conducting sheet 31 may be wavy or may be a structure composed of a plurality of V-shaped structures connected in sequence. Figure 3 The structural schematic diagram of the directional heat conducting layer 3 shown in the figure, in a specific embodiment, the directional heat conducting layer 3 includes an organic polymer adhesive layer 32 and a plurality of heat conducting sheets 31, each heat conducting sheet 31 extends in a direction perpendicular to the above longitudinal section, adjacent heat conducting sheets 31 are bonded by the organic polymer adhesive layer 32, and the heat conducting sheets 31 located on both sides are bonded with the organic polymer adhesive layer 32 on both sides in the first direction A. In this solution, the directional heat conducting layer 3 has high flexibility, high compressibility and high resilience, and can absorb the deformation of the power device 1 and the heat sink 2 caused by temperature change.

[0040] It is worth noting that the power device 1 mentioned in the present application may be a power chip, an inductor or a capacitor, etc. The heat sink 2 in the accompanying drawings is for illustration only, and the present application does not limit the specific type of the heat sink 2. For example, the heat sink 2 mentioned in the present application includes but is not limited to a fin-type heat sink or a liquid-cooled heat sink, etc.

[0041] When the above-mentioned directional heat-conducting layer 3 is specifically set, in some embodiments, the directional heat-conducting layer 3 includes a vertical graphene heat-conducting film. The vertical graphene heat-conducting film can provide a continuous heat conduction path for the power device 1 and the heat sink 2 between its first surface 3a and the second surface 3b, and the vertical graphene heat-conducting film has a high thermal conductivity and a low thermal resistance. Therefore, the directional heat-conducting layer 3 including the vertical graphene heat-conducting film is conducive to improving the rapid transfer of heat from the power device 1 to the heat sink 2. In addition, the vertical graphene heat-conducting film has a high resilience rate, can absorb the deformation of the power device 1 and the heat sink 2 caused by temperature change, and has a more stable thermal resistance and better high and low temperature stability.

[0042] Figure 4 This is a schematic diagram of the structure of a power module provided in this application. Figure 4As shown, in some embodiments, the power module includes a covering layer 4 whose thermal resistance is less than or equal to the thermal resistance of silicone grease. Specifically, the power module includes a covering layer 4, which is arranged on the surface of the vertical graphene thermal conductive film facing the power device 1; or, the power module includes a covering layer 4, which is arranged on the surface of the vertical graphene thermal conductive film facing away from the power device 1; or, the power module includes two covering layers 4, one of the two covering layers 4 is arranged on the surface of the vertical graphene thermal conductive film facing the power device 1, and the other of the two covering layers 4 is arranged on the surface of the vertical graphene thermal conductive film facing away from the power device 1. It is worth noting that when the covering layer 4 is arranged on the surface of the vertical graphene thermal conductive film facing the power device 1, in the process of preparing the power module, the vertical graphene thermal conductive film can be prepared on the surface of the vertical graphene thermal conductive film facing the power device 1, and the covering layer 4 can also be prepared on the surface of the component adjacent to the vertical graphene thermal conductive film on the side of the vertical graphene thermal conductive film facing the power device 1. When the covering layer 4 is arranged on the surface of the vertical graphene thermal conductive film facing away from the power device 1, in the process of preparing the power module, the vertical graphene thermal conductive film can be prepared on the surface of the vertical graphene thermal conductive film facing away from the power device 1, and the covering layer 4 can also be prepared on the surface of the component adjacent to the vertical graphene thermal conductive film on the side of the vertical graphene thermal conductive film facing away from the power device 1.

[0043] In some embodiments, the covering layer 4 has a certain wettability, which can further reduce the interfacial contact thermal resistance between the vertical graphene thermal conductive film and the adjacent components. Exemplarily, the covering layer 4 includes at least one of a first liquid metal layer, a phase change thermal conductive material layer, a thermal conductive silicone grease layer, a thermal conductive silver paste layer and a welding material layer. It is worth noting that when the covering layer 4 is a welding material layer, the covering layer 4 has welding characteristics, which can improve the bonding force of the interface and avoid interface delamination. Exemplarily, the first liquid metal layer can be a gallium-based, bismuth-based or indium-based liquid metal layer, or the first liquid metal layer can be a composite liquid metal layer including at least two of the three of gallium-based liquid metal, bismuth-based liquid metal and indium-based liquid metal.

[0044] Please continue to refer to Figure 4 When the cover layer 4 is a welding material layer, an assembly process of a power module is as follows:

[0045] Step 1: a layer of 1-10 um solder is prepared on the surface of the heat sink 2 facing the power device 1 and the surface of the power device 1 facing the heat sink 2 by one or more processes such as electroplating, spraying, vapor deposition and brushing; or, a layer of 1-10 um solder is prepared on the surface of the vertical graphene thermal conductive film facing the heat sink 2 and the surface facing the power device 1 by one or more processes such as electroplating, spraying, vapor deposition and brushing;

[0046] Step 2: Place the vertical graphene thermal conductive film on the heat sink 2, then place the power device 1 on the vertical graphene thermal conductive film, and then fix the power device 1 to the heat sink 2 by multiple screws;

[0047] Step 3, controlling the compression rate of the graphene thermal conductive film to be 3% to 80%;

[0048] Step 4: High temperature to the melting point of the welding material;

[0049] Step 5: Cooling, thereby achieving welding between the welding material layer and the structures on both sides thereof.

[0050] When the cover layer 4 is a solder tin layer, an assembly process of a power module is as follows:

[0051] Step 1: electroplating a 2-10 um tin layer on both sides of the vertical graphene thermal conductive film, or electroplating a 2-10 um tin layer on both the surface of the heat sink 2 facing the power device 1 and the surface of the power device 1 facing the heat sink;

[0052] Step 2: Place the vertical graphene thermal conductive film on the heat sink 2, then place the power device 1 on the vertical graphene thermal conductive film, and then fix the power device 1 to the heat sink 2 by multiple screws;

[0053] Step 3, controlling the compression rate of the graphene thermal conductive film to 30% to 50%;

[0054] Step 4: Place the entire device in step 3 in an oven at 215-225°C and heat for 10 minutes;

[0055] Step 5: Cooling, thereby achieving welding between the soldering tin layer and the structures on both sides thereof;

[0056] In some embodiments, the power module includes a ring-shaped insulating member, and the vertical graphene thermal conductive film is located in the middle of the ring formed by the insulating member to prevent debris falling from the edge of the vertical graphene thermal conductive film from causing a short circuit in the surrounding electronic components, thereby playing an insulating and protective role. Figure 5 and Figure 6 The component adjacent to the vertical graphene thermal conductive film on the side of the vertical graphene thermal conductive film facing the power device 1 is the first component B, the component adjacent to the vertical graphene thermal conductive film on the side of the vertical graphene thermal conductive film away from the power device 1 is the second component C, the insulating member is located between the first component B and the second component C, and is fixedly connected to both the first component B and the second component C. The insulating member, the first component B and the second component C are collectively enclosed to form a sealed first accommodating cavity, and the vertical graphene thermal conductive film is located in the first accommodating cavity.

[0057] In a specific implementation, the insulating member includes an insulating adhesive 7, a sealing insulating foam 6, a sealing insulating curing adhesive, and at least one of a thermally conductive insulating sheet and an insulating silicone pad. It is worth noting that when the insulating member is the insulating adhesive 7, the insulating adhesive 7 is used to both play the role of insulating protection and to fix the connection between the first component B and the second component C.

[0058] Please continue to refer to Figure 6 In specific implementation, an assembly process of a power module is as follows:

[0059] Step 1: electroplating a 2-10 um tin layer on both sides of the vertical graphene thermal conductive film, or electroplating a 2-10 um tin layer on both the surface of the heat sink 2 facing the power device 1 and the surface of the power device 1 facing the heat sink;

[0060] Step 2: Apply the insulating adhesive 7 to the area of ​​the power device 1 that is not in contact with the vertical graphene thermal conductive film, and use the insulating adhesive 7 as the above-mentioned insulating member;

[0061] Step 3: Place the vertical graphene thermal conductive film on the heat sink 2, and then connect the power device to the heat sink through the above-mentioned insulating adhesive 7;

[0062] Step 4: external processing and compression, controlling the compression rate of the graphene thermal conductive film to 30% to 50%;

[0063] Step 5: Place the entire device of step 4 in an oven at 215-225°C and heat for 10 minutes;

[0064] Step 6: Cooling, thereby achieving bonding between the insulating adhesive 7 and the structures on both sides thereof;

[0065] Step 7: Remove the external compression tooling.

[0066] It should be understood that the power device 1 can be fixedly connected to the heat sink 2 by adhesive or by multiple screws; the power module can also include a cover plate, and the cover plate and the heat sink 2 work together to clamp the power device between the cover plate and the heat sink 2. The thermal interface material layer is fixed between the power device 1 and the heat sink 2 by the clamping force between the power device 1 and the heat sink 2, or the thermal interface material layer includes an adhesive layer, and the thermal interface material layer is bonded to at least one of the power device 1 and the heat sink 2.

[0067] based on Figure 1 and Figure 2In the structure of the power module shown, in some embodiments, the directional heat conducting layer 3 includes a vertical boron nitride thermal conductive insulating film. Specifically, in a specific implementation, only a vertical boron nitride thermal conductive film is provided between the power device 1 and the heat sink 2, but no vertical graphene thermal conductive film is provided. The vertical boron nitride thermal conductive film not only has a low thermal resistance, but also has an insulating property. Therefore, there is no need to provide an insulating layer on the periphery of the vertical boron nitride thermal conductive film, which is beneficial to simplify the structure of the power module and improve the assembly efficiency of the power module. According to actual needs, in another specific implementation, there is both a vertical graphene thermal conductive film and a vertical boron nitride thermal conductive film between the power device 1 and the heat sink 2, that is, the power module adds a vertical boron nitride thermal conductive film on the basis of the vertical graphene thermal conductive film. In both cases, the power device 1 can be fixedly connected to the heat sink 2 by adhesive or by multiple screws; the power module can also include a cover plate, and the cover plate and the heat sink work together to clamp the power device between the two. Specifically, the power module also includes a cover plate, which is arranged on the side of the power device away from the heat sink. The cover plate includes a fixing device, and the orthographic projection of the fixing device on the heat sink does not intersect with the orthographic projection of the thermal interface material layer on the heat sink. The cover plate is fixedly connected to the heat sink through the fixing device.

[0068] In a specific embodiment, only a vertical boron nitride thermal conductive film is arranged between the power device 1 and the heat sink 2, but no vertical graphene thermal conductive film. The power module includes a covering layer 4, which is arranged on the surface of the vertical boron nitride thermal conductive film facing the power device 1; or, the power module includes a covering layer 4, which is arranged on the surface of the vertical boron nitride thermal conductive film away from the power device 1; or, the power module includes two covering layers 4, one of the two covering layers 4 is arranged on the surface of the vertical boron nitride thermal conductive film facing the power device 1, and the other of the two covering layers 4 is arranged on the surface of the vertical boron nitride thermal conductive film away from the power device 1. It is worth noting that when the covering layer 4 is arranged on the surface of the vertical boron nitride thermal conductive film facing the power device 1, in the process of preparing the power module, the vertical boron nitride thermal conductive film can be prepared on the surface of the vertical boron nitride thermal conductive film facing the power device 1, and the covering layer 4 can also be prepared on the surface of the component adjacent to the vertical boron nitride thermal conductive film on the side of the vertical boron nitride thermal conductive film facing the power device 1. When the covering layer 4 is arranged on the surface of the vertical boron nitride thermal conductive film facing away from the power device 1, in the process of preparing the power module, the vertical boron nitride thermal conductive film can be prepared on the surface of the vertical boron nitride thermal conductive film facing away from the power device 1, and the covering layer 4 can also be prepared on the surface of the component adjacent to the vertical boron nitride thermal conductive film on the side of the vertical boron nitride thermal conductive film facing away from the power device 1.

[0069] In another specific embodiment, there is both a vertical graphene thermal conductive film and a vertical boron nitride thermal conductive film between the power device 1 and the heat sink 2, that is, the directional thermal conductive film is a laminated structure including the vertical graphene thermal conductive film and the vertical boron nitride thermal conductive film. Further, the power module includes a covering layer 4, which is arranged on the surface of the laminated structure facing the power device 1; or, the power module includes a covering layer 4, which is arranged on the surface of the laminated structure away from the power device 1; or, the power module includes two covering layers 4, one of the two covering layers 4 is arranged on the surface of the laminated structure facing the power device 1, and the other of the two covering layers 4 is arranged on the surface of the laminated structure away from the power device 1. It is worth noting that when the covering layer 4 is arranged on the surface of the laminated structure facing the power device 1, in the process of preparing the power module, the laminated structure can be prepared on the surface of the laminated structure facing the power device 1, or the covering layer 4 can be prepared on the surface of the component adjacent to the laminated structure on the side of the laminated structure facing the power device 1. When the covering layer 4 is arranged on the surface of the stacked structure away from the power device 1, during the process of preparing the power module, the stacked structure can be prepared on the surface of the stacked structure away from the power device 1, or the covering layer 4 can be prepared on the surface of the component adjacent to the stacked structure on the side of the stacked structure away from the power device 1.

[0070] Figure 7 A schematic diagram of the structure of a power module provided in this application. Figure 1 and Figure 2 The structure of the power module shown in FIG. 1 may be, in some embodiments, Figure 7 As shown, the thermal interface material layer includes a second liquid metal layer 5 having a thermal resistance lower than that of silicone grease, and the second liquid metal layer 5 replaces the directional heat conduction layer 3 in the power module. That is to say, the power module includes a power device 1, a heat sink 2 and a thermal interface material layer, wherein the thermal interface material layer is arranged between the power device and the heat sink, and is thermally connected to both the power device and the heat sink, and the thermal interface material layer includes a second liquid metal layer 5 having a thermal resistance lower than that of silicone grease. In this solution, the thermal resistance of the second liquid metal layer 5 is less than that of silicone grease, so compared with the case where silicone grease is used as the thermal interface material layer, the heat dissipation efficiency of the power device 1 can be higher, thereby making the power module provided in the present application more suitable for integrated, miniaturized and high-power power equipment. It should be understood that the composition of the second liquid metal layer 5 may be the same as or different from that of the first liquid metal layer. For example, the second liquid metal layer 5 may be a gallium-based, bismuth-based or indium-based liquid metal layer, or the second liquid metal layer 5 may be a composite liquid metal layer including at least two of gallium-based liquid metal, bismuth-based liquid metal and indium-based liquid metal. This application does not specifically limit this, and any liquid metal layer with a thermal resistance less than that of silicone grease may be used as the second liquid metal layer 5 in this application.

[0071] Figure 8 A schematic diagram of the structure of a power module provided in this application, Fig. 9 This is a schematic diagram of the structure of another power module provided for this application. Figure 7 Based on the combination Figure 8 and Fig. 9 , the power module includes a ring-shaped insulating member, and the second liquid metal layer 5 is located in the middle of the ring surrounded by the insulating member. Exemplarily, the insulating member is located between the first component B and the second component C, and is fixedly connected to both the first component B and the second component C. The insulating member, the first component B and the second component C together form a sealed first accommodating cavity, and the second liquid metal layer 5 is located in the first accommodating cavity. In this way, it is possible to prevent the liquid metal in the second liquid metal layer 5 from flowing out and causing a short circuit of the surrounding power devices 1, thereby playing a role in insulation protection. In this case, the power device 1 can also be fixedly connected to the radiator 2 by an adhesive, or by a plurality of screws; the power module can also include a cover plate, and the cover plate and the radiator work together to clamp the power device between the two.

[0072] In a specific implementation, the insulating member includes an insulating adhesive 7, a sealing insulating foam 6, a sealing insulating curing adhesive, and at least one of a thermally conductive insulating sheet and an insulating silicone pad. It is worth noting that when the insulating member is the insulating adhesive 7, the insulating adhesive 7 is used to both play the role of insulating protection and to fix the connection between the first component B and the second component C.

[0073] In a specific implementation, the orthographic projection of the power device 1 on the heat sink 2 covers the orthographic projection of the thermal interface material layer on the heat sink 2, so that the entire thermal interface material layer can be used for heat dissipation of the power device 1, thereby improving the utilization rate of the thermal interface material layer. In another specific implementation, the power device includes a power chip and a plastic package. It is not difficult to understand that the power chip is plastic-encapsulated in the plastic package. In this case, the orthographic projection of the thermal interface material layer on the heat sink 2 covers the orthographic projection of the power chip on the heat sink 2. The power chip is the main heat-generating part of the power device 1. The orthographic projection of the thermal interface material layer on the heat sink 2 covers the orthographic projection of the power chip on the heat sink 2, so that the contact area between the thermal interface material layer and the power chip is larger, which is more conducive to efficient heat dissipation of the power chip.

[0074] In another specific implementation, the orthographic projection of the power device 1 on the heat sink 2 covers the orthographic projection of the thermal interface material layer on the heat sink 2, and the orthographic projection of the thermal interface material layer on the heat sink 2 covers the orthographic projection of the power chip on the heat sink 2, thereby improving the utilization rate of the thermal interface material layer and saving costs while ensuring the heat dissipation effect of the power chip.

[0075] Fig.10 This is a schematic diagram of the structure of another power module provided in this application. Fig.10 As shown, in some embodiments, the heat sink 2 includes a first heat sink 2a and a second heat sink 2b, the thermal interface material layer includes a first thermal interface material layer 301 and a second thermal interface material layer 302, the first thermal interface material layer 301 and the second thermal interface material layer 302 are respectively arranged on opposite sides of the power device 1, the first heat sink 2a is arranged on the side of the first thermal interface material layer 301 away from the power device 1, and the second heat sink 2b is arranged on the side of the second thermal interface material layer 302 away from the power device 1. That is, the power module 1 is a double-sided structure. Specifically, the two surfaces of each thermal interface material layer are fixed with a cover layer 4, and the surrounding side of each thermal interface material layer is fixed with an insulating member (for example: sealing insulating foam 6), and the insulating member, the power device 1 and the corresponding heat sink 2 together seal the corresponding thermal interface material layer and the cover layer 4 in the accommodating cavity.

[0076] Fig.11 A schematic diagram of the structure of a power module provided in this application, Fig.12 for Fig.11 Exploded view of the power module shown. Based on Figure 5 , Figure 8 and Fig.10 The power module shown is Fig.11 and Fig.12 As shown, in some embodiments, the power device 1 includes a main body 11 and a terminal 12, the main body 11 includes a top surface, a bottom surface and a side surface, the top surface and the bottom surface are parallel to the thermal interface material layer, and the side surface connects the top surface and the bottom surface. The terminal 12 is located on the side of the main body 11 and is electrically connected to the main body 11. Further, the power module includes an insulating ring 8, the insulating ring 8 is located on the periphery of the insulating member (for example: the sealing insulating foam 6) and surrounds the insulating member. The positive projection of the terminal 12 on the heat sink 2 overlaps with the positive projection of the insulating ring 8 on the heat sink 2 at least partially. The heat sink 2 is usually a metal structure with conductivity. The terminal 12 of the power device 1 is separated from the heat sink 2 by the insulating ring 8, which can ensure good insulation between the terminal 12 and the heat sink 2. Exemplarily, the positive projection of the terminal 12 on the heat sink 2 does not exceed the positive projection of the insulating ring 8 on the heat sink 2; the insulating ring 8 and the insulating member can be separate structures or integrally formed structures. In specific implementation, they can be set according to actual needs. It is not difficult to understand that this solution is also applicable to other power modules mentioned in this application.

[0077] In a specific implementation, the first component B is a power device 1, and the second component C is a heat sink 2. That is, the power module is a topless structure, the first surface 3a of the thermal interface material layer is directly connected to the power device 1, the second surface 3b of the thermal interface material layer is directly connected to the heat sink 2, and the thermal interface material layer is TIM1.5.

[0078] In another specific implementation, the power module includes a shell having a housing cavity, the power device 1 is located in the housing cavity of the shell, and the heat sink 2 is located outside the housing cavity of the shell. The shell includes a plate body, and the plate body is arranged on the side of the thermal interface material layer away from the power device 1. That is, the first component B is the power device 1, and the second component C is the plate body. The thermal interface material layer is located between the power device 1 and the plate body, the first surface 3a is directly connected to the power device 1, and the second surface 3b is directly connected to the plate body, and the thermal interface material layer is TIM1.

[0079] In another specific implementation, the power module includes a shell having a housing cavity, the power device 1 is located in the housing cavity of the shell, and the heat sink 2 is located outside the housing cavity. The shell includes a plate body, the plate body is located on the side of the thermal interface material layer facing the power device 1, the first component B is the plate body, and the second component C is the heat sink 2. That is, the thermal interface material layer is located between the plate body and the heat sink 2, the first surface 3a is directly connected to the plate body, the second surface 3b is directly connected to the heat sink 2, and the thermal interface material layer is TIM2.

[0080] Of course, the power module mentioned in this application is not limited to the above three forms, and can also be in other forms, which are not listed here one by one.

[0081] A power device provided in the present application includes a circuit board and the above-mentioned power module, and the power module is electrically connected to the circuit board to achieve corresponding functions. In this scheme, when the thermal interface material layer includes a directional heat conduction layer 3, a plurality of heat conducting sheets 31 in the directional heat conduction layer 3 of the power module can form a plurality of continuous heat conduction paths between the power device 1 and the heat sink 2, thereby strengthening the conduction of heat from the power device 1 to the heat sink 2, and thus helping to improve the heat dissipation efficiency of the power module. At the same time, the thermal resistance of the directional heat conduction layer 3 is less than the thermal resistance of silicone grease, so compared with the case where silicone grease is used as the thermal interface material layer, the heat dissipation efficiency of the power device 1 can be higher. When the thermal interface material layer includes a second liquid metal layer 5 whose thermal resistance is lower than the thermal resistance of silicone grease, compared with the case where silicone grease is used as the thermal interface material layer, the heat dissipation efficiency of the power device 1 can also be higher.

[0082] It is worth noting that the power module and power device provided in this application can also be used in heat conduction scenarios such as 5G.

[0083] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A power module, It is characterized in that It includes a power device, a heat sink and a thermal interface material layer, wherein the thermal interface material layer includes a directional heat conduction layer, the directional heat conduction layer is arranged between the power device and the heat sink, and is thermally connected to the power device and the heat sink; The directional heat conducting layer includes a first surface and a second surface, the first surface faces the power device, and the second surface faces away from the power device; the directional heat conducting layer has a plurality of heat conducting plates, the plurality of heat conducting plates are arranged at intervals along a first direction, and each of the heat conducting plates extends from the first surface to the second surface; the first direction is parallel to the first surface; the thermal resistance of the directional heat conducting layer is lower than the thermal resistance of the silicone grease.

2. The power module according to claim 1, It is characterized in that The directional heat-conducting layer includes a vertical graphene heat-conducting film.

3. The power module according to claim 1 or 2, It is characterized in that The directional heat conduction layer includes a vertical boron nitride heat conduction insulation film.

4. The power module according to claim 2, It is characterized in that The power module comprises a covering layer, wherein the thermal resistance of the covering layer is less than or equal to the thermal resistance of the silicone grease; and the power module satisfies at least one of the following conditions: The power module comprises a cover layer, and the cover layer is arranged on the surface of the vertical graphene thermal conductive film facing the power device; or, The power module comprises a cover layer, and the cover layer is arranged on the surface of the vertical graphene thermal conductive film away from the power device; or, The power module comprises two covering layers, one of the two covering layers is arranged on a surface of the vertical graphene thermal conductive film facing the power device, and the other of the two covering layers is arranged on a surface of the vertical graphene thermal conductive film facing away from the power device.

5. The power module according to claim 4, It is characterized in that The covering layer includes at least one of a first liquid metal layer, a phase-change thermal conductive material layer, a thermal conductive silicone grease layer, a thermal conductive silver paste layer, and a welding material layer.

6. A power module, It is characterized in that It includes a power device, a heat sink and a thermal interface material layer, wherein the thermal interface material layer is arranged between the power device and the heat sink and is thermally connected to the power device and the heat sink; the thermal interface material layer includes a second liquid metal layer, and the thermal resistance of the second liquid metal layer is lower than the thermal resistance of silicone grease.

7. The power module according to any one of claims 1 to 6, It is characterized in that The orthographic projection of the power device on the heat sink covers the orthographic projection of the thermal interface material layer on the heat sink.

8. The power module according to any one of claims 1 to 7, It is characterized in that The power device comprises a power chip and a plastic package, wherein the power chip is plastic-packaged in the plastic package; The orthographic projection of the thermal interface material layer on the heat sink covers the orthographic projection of the power chip on the heat sink.

9. The power module according to claim 2, 4, 5 or 6, It is characterized in that The power module comprises an insulating member, which is in a ring shape. The thermal interface material layer is located in the middle of the ring formed by the insulating member.

10. The power module according to claim 9, It is characterized in that The insulating component includes at least one of an insulating adhesive, a sealing insulating foam, a sealing insulating curing adhesive, a thermally conductive insulating sheet, and an insulating silicone pad.

11. The power module according to claim 9 or 10, It is characterized in that The power device comprises a main body and a terminal, the main body comprises a top surface, a bottom surface and a side surface, the top surface and the bottom surface are both parallel to the thermal interface material layer, and the side surface connects the top surface and the bottom surface; The terminal is located on the side of the main body and is electrically connected to the main body; The power module comprises an insulating ring, which is located at the periphery of the insulating member and surrounds the insulating member; The orthographic projection of the terminal on the heat sink at least partially overlaps with the orthographic projection of the insulating ring on the heat sink.

12. The power module according to any one of claims 1 to 11, It is characterized in that It comprises a housing having a housing cavity, wherein the power device is located in the housing cavity, and the heat sink is located outside the housing cavity; The shell includes a plate body, and the plate body is arranged on a side of the thermal interface material layer facing the power device, or the plate body is arranged on a side of the thermal interface material layer facing away from the power device.

13. The power module according to any one of claims 1 to 11, It is characterized in that The heat sink comprises a first heat sink and a second heat sink, and the thermal interface material layer comprises a first thermal interface material layer and a second thermal interface material layer; The first thermal interface material layer and the second thermal interface material layer are respectively arranged on opposite sides of the power device, the first heat sink is arranged on the side of the first thermal interface material layer away from the power device, and the second heat sink is arranged on the side of the second thermal interface material layer away from the power device.

14. The power module according to any one of claims 1 to 11, It is characterized in that The power module further comprises a cover plate, which is arranged on a side of the power device away from the heat sink; The cover plate comprises a fixing device, the orthographic projection of the fixing device on the heat sink does not intersect with the orthographic projection of the thermal interface material layer on the heat sink, and the cover plate is fixedly connected to the heat sink via the fixing device.

15. A power device, It is characterized in that It comprises a circuit board and a power module as claimed in any one of claims 1 to 14, wherein the power module is electrically connected to the circuit board.

Images