Vehicle-mounted power tube heat dissipation structure

Abstract

The invention provides a vehicle-mounted power tube heat dissipation structure which comprises a PCB, a power tube attached to the PCB and a radiator corresponding to the heat dissipation face of the power tube, one face, attached to the heat dissipation face of the power tube, of the radiator is provided with one or more cofferdam structures, and a heat conduction interface material is arranged in an area defined by the cofferdam structures. The heat dissipation surface of the power tube is attached to the heat conduction interface material. The heat conduction insulating layer and the radiator are integrated, no extra insulating part needs to be installed, the manufacturing process is simplified, and the production efficiency is improved. And through the cofferdam structure arranged on the radiator, the heat conduction material is limited in the cofferdam, so that the problems of horizontal slippage, vertical flow and the like of the heat conduction material under the influence of temperature change and vibration factors are prevented, and the thermal reliability of the power supply device is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of new energy vehicles, in particular to a vehicle-mounted power tube heat dissipation structure. BACKGROUND

[0002] With the continuous upgrading of new energy vehicle technology and the acceleration of product iteration speed, vehicle-mounted power supply products such as vehicle-mounted chargers are rapidly developing towards high power density, miniaturization and low cost. At present, in vehicle-mounted power supply products, the power tube is designed with bottom heat dissipation packaging, which realizes effective conduction and dissipation of heat through the fitting of three-dimensional waterway surface. However, due to the more intense vibration of the power tube in the vehicle-mounted environment than in the general environment, the reliability of the existing vehicle-mounted power supply product power tube heat dissipation structure is low. SUMMARY

[0003] The present application relates to the technical field of new energy vehicles, in particular to a vehicle-mounted power tube heat dissipation structure.

[0004] The technical scheme adopted by the present application is: The present application provides a vehicle-mounted power tube heat dissipation structure, comprising: a PCB circuit board, a power tube mounted on the PCB circuit board, and a heat sink corresponding to the heat dissipation surface of the power tube, one or more cofferdam structures are arranged on one side of the heat sink fitted with the heat dissipation surface of the power tube, a heat-conducting interface material is arranged in the area surrounded by the cofferdam structure, and the heat dissipation surface of the power tube is fitted with the heat-conducting interface material.

[0005] Preferably, the projection area B of the area surrounded by the cofferdam structure is greater than or equal to the pin area A of the power tube, and the depth of the area surrounded by the cofferdam structure is greater than or equal to 50 um.

[0006] Further, a heat-conducting insulating layer is arranged on the surface of the cofferdam structure.

[0007] Preferably, the thickness of the heat-conducting insulating layer is in the range of 50-250 um.

[0008] Preferably, the material of the heat-conducting insulating layer is any one or a combination of Al2O3, AlN, Si3N4, PI, PEI and epoxy resin composite.

[0009] Preferably, the heat-conducting insulating layer arranged on the surface of the cofferdam structure is formed in an integrated manner with the heat sink through any one of the processing technologies of spraying, gluing, welding, hot pressing and micro-arc oxidation.

[0010] Preferably, the thickness of the heat-conducting interface material is in the range of 150-500 um.

[0011] Further, the cofferdam structure is a groove provided on the surface of the heat sink, and an included angle between a side wall around the groove and a bottom surface is a right angle or an oblique angle.

[0012] Further, a thickness of the heat-conducting insulation layer is h1, a thickness of the heat-conducting interface material is h2, a distance between the cofferdam structure and a top edge of the power tube package is L, a creepage distance from a pin of the power tube to a top of the power tube body is L1, and L+h1+h2+L1≥3.7 mm.

[0013] In the first embodiment, the cofferdam structure is provided in one-to-one correspondence with the power tube.

[0014] In the second embodiment, the heat-conducting interface material is arranged in an area surrounded by the plurality of power tubes and the cofferdam structure.

[0015] In the third embodiment, the heat-conducting interface material is arranged in an area surrounded by the plurality of power tubes and the cofferdam structure.

[0016] Further, the PCB circuit board is pressed by a support column arranged on an inner side of a cover plate of the power device housing, and the support column is opposite to a position where the power tube is arranged on the PCB circuit board.

[0017] Compared with the prior art, the present application has the following advantages: 1. The heat-conducting insulation layer and the heat sink are integrated, and no additional insulation member is needed, so that the manufacturing process is simplified, and the production efficiency is improved.

[0018] 2. The heat-conducting interface material is arranged to facilitate close adhesion of the heat sink and the power tube, so that the heat conduction efficiency is improved, and part of vibration is buffered; and the cofferdam structure limits the heat-conducting interface material on the heat sink, so that horizontal sliding and vertical flow of the heat-conducting interface material caused by temperature change and strong vibration in a vehicle-mounted environment are prevented, and the heat dissipation reliability of the power device such as a vehicle-mounted charger is improved.

[0019] 3. The cofferdam structure increases an electrical insulation distance between a pin of the power tube, a heat dissipation surface, and a water channel heat dissipation surface, and improves the electrical reliability of the power supply product.

[0020] 4. Compared with a structure without the cofferdam structure, a wall thickness of a water channel surface in the cofferdam structure is reduced, so that the thermal resistance is further reduced, and the heat dissipation capacity of the power device is increased. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description only constitute some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort.

[0022] Figure 1 is a structural schematic diagram of a specific embodiment of the present application; Figure 2 is a structural schematic diagram of a single cofferdam structure corresponding to a power tube in a specific embodiment of the present application; Figure 3 is a structural schematic diagram of a surface inwardly recessed to form a right-angle groove in a specific embodiment of the present application; Figure 4 is a structural schematic diagram of a surface inwardly recessed to form an oblique-angle groove in a specific embodiment of the present application; Figure 5 is a schematic diagram of a plurality of power tubes corresponding to one cofferdam structure in a specific embodiment of the present application; Figure 6 is a structural schematic diagram of a specific embodiment of the present application in which a support column is added; Figure 7 is a flowchart of a specific embodiment of the present application; Figure 8 is a structural schematic diagram of another embodiment of the present application; 101, heat sink; 102, cofferdam structure; 103, heat-conducting insulation layer; 2, heat-conducting interface material; 301, power tube; 4, PCB circuit board; 501, threaded connecting piece; 601, shell cover plate; 602, support column. DETAILED DESCRIPTION

[0023] In order to make the technical problems to be solved by the present application, the technical solutions and beneficial effects more clear and explicit, the present application will be further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0024] The principles and structures of the present application will be described in detail below in combination with the drawings and embodiments.

[0025] In the prior art, the existing vehicle-mounted power supply products such as vehicle-mounted chargers have low reliability, mainly due to the great influence of power tube vibration in a vehicle-mounted environment, which results in that in the actual use process, the power tube heat dissipation surface cannot be effectively attached due to the influence of temperature changes and vibration and other factors, affecting the heat conduction efficiency.

[0026] To this end, as Figure 1As shown, the application provides a vehicle-mounted power tube heat dissipation structure, which is applied to power supply products such as vehicle-mounted chargers, and specifically comprises: a PCB circuit board 4, a power tube 301, and a heat sink 101. The PCB circuit board 4 is attached with a plurality of power tubes 301, and the side of the power tube 301 opposite to the PCB circuit board 4 is a heat dissipation surface, that is, the power tube 301 is packaged in a top heat dissipation form, and the pins of the power tube 301 are welded to the PCB circuit board 4 to realize electrical connection; the heat sink 101 is fixedly connected with the PCB circuit board 4, and the side of the heat sink 101 opposite to the heat dissipation surface of the power tube 301 is provided with one or more cofferdam structures 102, the bottom surface of the area surrounded by the cofferdam structure 102 is provided with a heat-conducting interface material 2, and the heat-conducting interface material 2 is used to be attached to the heat dissipation surface of the power tube 301. After the heat sink 101 is fixedly connected with the PCB circuit board 4, the cofferdam structure 102 limits the heat-conducting interface material 2 within the heat dissipation area of the power tube 301, and the heat-conducting interface material 2 is tightly attached to the heat dissipation surface of the power tube 301.

[0027] The vehicle-mounted power tube heat dissipation structure provided by the application considers that the attachment surface of the heat dissipation surface of the power tube and the heat sink 101 is not absolutely flat, so the deformable heat-conducting interface material 2 is arranged between them, which can be tightly attached to the heat dissipation surface of the power tube 301 and the heat sink 101 through extrusion, so as to improve the heat conduction efficiency. Further, the cofferdam structure 102 arranged on the heat sink limits the heat-conducting interface material 2 within the cofferdam, so as to prevent the heat-conducting interface material 2 from horizontally sliding, vertically flowing and other problems under the influence of temperature changes and strong vibration factors in the vehicle-mounted environment, and improve the thermal reliability of the power supply device.

[0028] In addition, the attachment surface of the heat sink 101 can be specifically provided with a three-dimensional water channel and other heat dissipation structures, or other radiation type heat dissipation structures.

[0029] Specifically, the PCB circuit board 4 can be fixedly connected with the heat sink through a threaded connecting piece 501, so that the power tube 301, the heat-conducting interface material 2 and the heat sink are tightly attached, and the cofferdam structure 102 limits the heat-conducting interface material 2 within the area surrounded by the cofferdam structure 102.

[0030] In further embodiments, the surface of the cofferdam structure 102 is provided with a heat-conducting insulating layer 103, and the heat-conducting interface material 2 is arranged outside the heat-conducting insulating layer 103, so that the power tube 301 is kept in an insulating state with the heat sink body when being attached to the heat sink. Through the integration of the heat-conducting insulating layer 103 and the heat sink, it is not necessary to additionally install an insulating piece, so that the manufacturing process can be simplified, and the production efficiency is improved.

[0031] In other embodiments, as Figure 8As shown, the heat-conducting insulating layer 103 can also be arranged inside the heat sink, and integrated with the heat sink by pressing or other methods. The outer layer is a metal heat dissipation layer such as aluminum or aluminum alloy, copper or copper alloy, and the core is the heat-conducting insulating layer 103.

[0032] In specific embodiments, as shown in Figures 2 to 4 The projection area B of the area surrounded by the cofferdam structure 102 is greater than or equal to the pin area A of the power tube 301, that is, the projection of the area surrounded by the cofferdam structure 102 on the mainboard includes the range of the power tube 301 and the power tube pins, and the depth of the area surrounded by the cofferdam structure 102 is greater than or equal to 50 um.

[0033] The heat-conducting insulating layer 103 arranged on the bottom surface of the area of the cofferdam structure 102, that is, the heat-conducting insulating layer 103 arranged on the surface of the cofferdam structure 102, has a thickness in the range of 50-250 um, which can be selected according to actual conditions, and is preferably greater than or equal to 80 um.

[0034] In further embodiments, the material of the heat-conducting insulating layer 103 is any one or a combination of Al2O3, AlN, Si3N4, PI, PEI, and epoxy resin composite material.

[0035] In further embodiments, the heat-conducting insulating layer 103 arranged on the surface of the cofferdam structure 102 is formed into an integrated material with the heat sink by any one of spraying, gluing, welding, hot pressing, and micro-arc oxidation.

[0036] In further embodiments, the heat-conducting interface material 2 is any one of heat-conducting gel, heat-conducting pad, or heat-conducting phase change material, that is, the heat-conducting interface material is a heat-conducting layer arranged in the area of the cofferdam structure 102 of the heat sink 101, and is used for heat conduction between the power tube 301 and the heat sink 101. The thickness of the heat-conducting interface material 2 is in the range of 150-500 um, and is preferably in the range of 150-350 um. Excessive thickness of the heat-conducting material will increase the interface thermal resistance and affect the actual heat dissipation effect of the power supply device. Moreover, the thickness of the heat-conducting interface material 2 is selected not only considering the heat conductivity, but also considering the electrical insulation distance between the power tube pins, the heat dissipation surface, and the water channel heat dissipation surface, to improve the electrical reliability of the power supply product.

[0037] In specific embodiments, the cofferdam structure 102 is a groove arranged on the lower surface of the heat sink 101, as shown in Figure 3 , 4 The groove can be a direct inward recess on the lower surface, or a circle of protruding parts surrounding the groove.

[0038] In the case of multiple cofferdam structures, the lower surface of the heat sink 101 has multiple grooves, and the positions between the grooves are convex, so that the surface of the heat sink 101 as a whole presents a concave-convex structure. Or make the surface of the heat sink 101 as a whole present a concave-convex pattern.

[0039] The angle between the side wall around the groove and the bottom surface is a right angle or an oblique angle, which is not limited. The side wall except the bottom of the groove and the surface of the heat sink at other positions can be provided with or without a heat-conducting insulation layer 103, which is determined according to the actual electrical insulation and structural processing requirements. In addition, the number of cofferdam structures 102 is not required, and is determined according to the number of power tubes 301 to be cooled and the structural space and layout space.

[0040] As shown in Figure 2 , the thickness h1 of the heat-conducting insulation layer 103, the thickness h2 of the heat-conducting interface material 2, the distance L between the cofferdam structure and the top edge of the power tube 301 (in the third embodiment, it refers to the outermost cofferdam structure), and the creepage distance L1 from the pin of the power tube 301 to the top of the power tube 301 body satisfy the following relationship: L+h1+h2+L1≥3.7mm. That is, by increasing the electrical insulation distance between the power tube pin, the heat dissipation surface and the water channel heat dissipation surface through the cofferdam structure, the electrical reliability of the power supply product is improved.

[0041] The specific processing method of the cofferdam structure 102 is suitable for various embodiments, and can be formed by pressure casting, mechanical processing, setting a cofferdam support frame (i.e. forming a convex part) or a cofferdam glue (i.e. forming a convex part).

[0042] The number of cofferdam structures 102 arranged opposite to the power tube 301 has two embodiments, which are as follows: In the first embodiment, as shown in Figures 1 to 4 , one cofferdam structure 102 is arranged corresponding to each power tube 301, that is, the power tube 301 and the cofferdam structure 102 are one-to-one corresponding, which can be adapted to install each power tube 301.

[0043] In the second embodiment, as shown in Figure 5 , 6 , in order to improve the processing and production efficiency of the heat sink 101, multiple power tubes 301 share one cofferdam structure 102 as a whole, the heat-conducting interface material 2 is arranged on the surface of the heat-conducting insulation coating of the cofferdam structure 102, and multiple power tubes 301 are attached to the heat-conducting interface material 2 in the cofferdam structure 102.

[0044] In the third embodiment, the power tube 301 can also correspond to multiple cofferdam structures 102, that is, the heat-conducting interface material 2 is arranged on the heat-conducting insulating coating surface of each cofferdam structure 102, and one power tube 301 is attached to the heat-conducting interface material 2 in the multiple cofferdam structures 102.

[0045] In a further embodiment, as shown in Figure 6 In order to solve this problem, a support column 602 can be arranged at the position of the power tube 301 on the shell cover plate 601. When the shell cover plate 601 is installed (the shell cover plate 601 is connected to the shell or the edge of the heat exchanger through the threaded connection 501), the support column 602 presses the PCB circuit board 4 downward, reduces the deformation and assembly gap of the PCB circuit board 4, controls the thickness of the heat-conducting material in a smaller range, and reduces the interface thermal resistance.

[0046] The application further provides a power supply device comprising the vehicle-mounted power tube heat dissipation structure.

[0047] In a specific embodiment, the power supply device is a vehicle-mounted charger, and the heat sink is a shell water channel arranged in the shell of the vehicle-mounted charger.

[0048] As shown in Figure 7 For the heat dissipation structure described in the application, a manufacturing method is further provided, which comprises the following steps: S101, a cofferdam structure is formed on the surface of the heat sink structure; S102, a heat-conducting insulating layer is sprayed on the surface of the cofferdam structure; S103, a heat-conducting interface material is applied to the position of the cofferdam structure with the heat-conducting insulating layer; S104, the PCB circuit board of the assembled power tube is assembled with the heat sink, so that the heat dissipation surface of the power tube is in full contact with the heat-conducting interface material.

[0049] The specific implementation of the manufacturing method is as follows: S101, a cofferdam structure is formed on the surface of the heat sink structure; S102, a heat-conducting insulating layer is sprayed on the surface of the cofferdam structure; S103, a heat-conducting interface material is applied to the position of the cofferdam structure with the heat-conducting insulating layer; S104 assembles the PCB circuit board of the power transistor with the heat sink and other housings, so that the heat dissipation surface of the top of the power transistor is in full contact with the thermal conductive gel material, and the thermal conductive gel material is confined to the heat dissipation surface of the power transistor by the dike structure, and the interface thickness is guaranteed.

[0050] It should be noted that the terminology used above is for describing particular embodiments only and is not intended to limit the exemplary embodiments of the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form as well. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0051] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0052] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0053] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

Claims

1. A heat dissipation structure for automotive power transistors, comprising: A PCB circuit board, a power transistor mounted on the PCB circuit board, and a heat sink corresponding to the heat dissipation surface of the power transistor, characterized in that one or more dam structures are provided on the side of the heat sink that is in contact with the heat dissipation surface of the power transistor, and a thermally conductive interface material is provided in the area enclosed by the dam structure, and the heat dissipation surface of the power transistor is in contact with the thermally conductive interface material.

2. The vehicle-mounted power tube heat dissipation structure as described in claim 1, characterized in that, The projected area B of the region enclosed by the cofferdam structure is greater than or equal to the area A of the power transistor pin region, and the depth of the region enclosed by the cofferdam structure is greater than or equal to 50 μm.

3. The vehicle-mounted power tube heat dissipation structure as described in claim 1, characterized in that, The surface of the cofferdam structure is provided with a thermally conductive and insulating layer.

4. The vehicle-mounted power tube heat dissipation structure as described in claim 3, characterized in that, The thickness of the thermally conductive insulating layer ranges from 50 to 250 μm.

5. The vehicle-mounted power tube heat dissipation structure as described in claim 3, characterized in that, The material of the thermally conductive insulating layer is any one or a combination of Al2O3, AlN, Si3N4, PI, PEI, and epoxy resin composite materials.

6. The vehicle-mounted power tube heat dissipation structure as described in claim 3, characterized in that, The thermally conductive and insulating layer on the surface of the cofferdam structure is integrated with the radiator through any one of the following processing techniques: spraying, gluing, welding, hot pressing, or micro-arc oxidation.

7. The vehicle-mounted power tube heat dissipation structure as described in claim 1, characterized in that, The thickness of the thermally conductive interface material ranges from 150 to 500 μm.

8. The vehicle-mounted power transistor heat dissipation structure as described in claim 1, characterized in that, The cofferdam structure is a groove provided on the surface of the radiator, and the angle between the side walls of the groove and the bottom surface is a right angle or an oblique angle.

9. The vehicle-mounted power tube heat dissipation structure as described in claim 3, characterized in that, The thickness of the thermally conductive insulating layer is h1, the thickness of the thermally conductive interface material is h2, the distance between the cofferdam structure and the top edge of the power transistor package is L, the creepage distance from the pin of the power transistor to the top of the power transistor body is L1, and L+h1+h2+L1≥3.7mm.

10. The vehicle-mounted power transistor heat dissipation structure as described in any one of claims 1 to 9, characterized in that, The cofferdam structure is configured in a one-to-one correspondence with the power tube; or one power tube is configured to correspond to multiple cofferdam structures; or multiple power tubes are configured to be bonded to a heat-conducting interface material within the area enclosed by one cofferdam structure.

11. The vehicle-mounted power transistor heat dissipation structure as described in claim 1, characterized in that, The PCB circuit board is pressed together by a support column provided inside the cover plate of the power supply unit housing, and the support column is directly opposite the position of the power transistor on the PCB circuit board.

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