Power tube heat dissipation structure, power supply device and processing and assembling method

Abstract

The invention provides a power tube heat dissipation structure, a power supply device and a processing and assembling method.The heat dissipation structure comprises a PCB, a power tube attached to the PCB and a radiator corresponding to the heat dissipation face of the power tube, and one face, attached to the heat dissipation face of the power tube, of the radiator is provided with one or more cofferdam structures; a heat conduction interface material is arranged in an area defined by the cofferdam structure, and the heat dissipation face 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 invention relates to the technical field of new energy vehicles, and in particular to a power tube heat dissipation structure, a power supply device and a processing and assembly method. Background Art

[0002] With the continuous upgrading of new energy vehicle technology and the acceleration of product iteration, on-board power products such as on-board chargers are rapidly developing towards high power density, miniaturization and low cost. At present, power tubes in on-board power products mostly adopt the design of bottom heat dissipation packaging, which realizes effective heat conduction and dissipation by fitting the three-dimensional waterway surface.

[0003] The heat dissipation surface of the power tube and the three-dimensional water channel surface are not absolutely flat, so a deformable thermal conductive material needs to be arranged between them, which can be tightly fitted with the heat dissipation surface of the power tube and the three-dimensional water channel surface through extrusion. However, under the influence of temperature changes and vibration factors, the thermal conductive material is prone to horizontal slippage, vertical flow and other problems, which affect the heat dissipation reliability of the power supply device. Summary of the invention

[0004] In order to solve the technical problem of the complicated and high cost of the power tube heat dissipation structure in the above-mentioned prior art, the present invention provides a power tube heat dissipation structure, a power supply device and a processing and assembly method.

[0005] The technical solution adopted by the present invention is:

[0006] The present invention proposes a 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 side of the heat sink that is in contact with the heat dissipation surface of the power tube is provided with one or more cofferdam structures, a thermal interface material is arranged in the area enclosed by the cofferdam structure, and the heat dissipation surface of the power tube is in contact with the thermal interface material.

[0007] Preferably, the projection area B of the area enclosed by the cofferdam structure is ≥ the area A of the power tube pin area, and the depth of the area enclosed by the cofferdam structure is ≥ 50 mm.

[0008] Furthermore, a heat-conducting insulating layer is provided on the surface of the cofferdam structure.

[0009] Preferably, the thickness of the thermally conductive insulating layer is in the range of 50-250 um.

[0010] Preferably, the material of the thermally conductive insulating layer is any one of Al2O3, AlN, Si3N4, PI, PEI, and epoxy resin composite materials.

[0011] Preferably, the thermally conductive insulating layer disposed on the surface of the cofferdam structure is integrated with the heat sink by any one of a processing technique including spraying, gluing, welding, hot pressing and micro-arc oxidation.

[0012] Preferably, the thermally conductive interface material is any one of a thermally conductive gel, a thermally conductive gasket or a thermally conductive phase change material.

[0013] Preferably, the thickness of the thermal interface material is in the range of 150-500 mm.

[0014] Furthermore, the cofferdam structure is a groove arranged on the surface of the radiator, and the angle between the side walls around the groove and the bottom surface is a right angle or an oblique angle.

[0015] Preferably, the cofferdam structure is formed by integral die-casting, machining, setting a cofferdam support frame or cofferdam glue.

[0016] In the first embodiment, the cofferdam structures are arranged in one-to-one correspondence with the power tubes.

[0017] In the second embodiment, the plurality of power tubes are bonded to a thermal interface material disposed in an area enclosed by a cofferdam structure.

[0018] Furthermore, the PCB board is pressed by a support column arranged on the inner side of the cover plate of the power supply device housing, and the support column is directly opposite to the position where the power tube is arranged on the PCB board.

[0019] The present invention also provides a power supply device, comprising the above-mentioned power tube heat dissipation structure.

[0020] The present invention also provides a processing and assembly method for a power tube heat dissipation structure, comprising the steps of:

[0021] Processing the surface of the radiator structure to form a cofferdam structure;

[0022] Spray a thermally conductive insulating layer on the surface of the cofferdam structure;

[0023] Applying thermal interface material at the location of the cofferdam structure with the thermally conductive insulating layer;

[0024] Assemble the PCB circuit board on which the power tube is assembled and the heat sink so that the heat dissipation surface of the power tube is in full contact with the thermal interface material.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] 1. By integrating the thermal insulation layer and the heat sink, there is no need to install additional insulation parts, which simplifies the manufacturing process and improves production efficiency.

[0027] 2. The cofferdam structure set on the radiator confines the thermal conductive material inside the cofferdam to prevent horizontal slippage and vertical flow of the thermal conductive material under the influence of temperature changes and vibration factors, thereby improving the thermal reliability of the power supply device. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0029] Figure 1 It is a structural schematic diagram of a specific embodiment of the present invention;

[0030] Figure 2 is a schematic structural diagram of a groove formed by a protrusion in a specific embodiment of the present invention;

[0031] Figure 3 It is a schematic diagram of a structure in which a right-angle groove is formed by indenting the surface in a specific embodiment of the present invention;

[0032] Figure 4 It is a schematic diagram of the structure in which the surface is sunken to form an oblique angle groove in a specific embodiment of the present invention;

[0033] Figure 5 is a schematic diagram of a cofferdam structure corresponding to multiple power tubes in a specific embodiment of the present invention;

[0034] Figure 6 It is a schematic diagram of the structure in which a support column is added in a specific embodiment of the present invention;

[0035] Figure 7 is a flow chart in a specific embodiment of the present invention;

[0036] Figure 8 is a schematic structural diagram of other embodiments of the present invention;

[0037] 101. radiator; 102. cofferdam structure; 103. thermal insulation layer; 2. thermal interface material; 301. power tube; 4. PCB circuit board; 501. threaded connector; 601. housing cover; 602. support column. DETAILED DESCRIPTION

[0038] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0039] The principle and structure of the present invention are described in detail below with reference to the accompanying drawings and embodiments.

[0040] In the prior art, since the heat dissipation surface of the power tube and the three-dimensional water channel surface cannot be processed to be completely flat, there may be a gap when they are directly fitted together, so a flexible thermal conductive material needs to be arranged between the two. The thermal conductive material is filled between the heat dissipation surface of the power tube and the three-dimensional water channel surface to achieve a close fit between the two, thereby improving the heat conduction efficiency. However, in actual use, affected by factors such as temperature changes and vibrations, the thermal conductive material may slip horizontally or flow vertically. These problems not only affect the heat dissipation effect, but also weaken the overall thermal reliability of the power supply device, thereby posing a hidden danger to the long-term stable operation of the equipment.

[0041] In this regard, Figure 1 As shown, the present invention proposes a power tube heat dissipation structure, which is applied to power products such as vehicle chargers, and specifically includes: a PCB circuit board 4, a power tube 301 and a heat sink 101. A plurality of power tubes 301 are mounted on the PCB circuit board 4, and the side of the power tube 301 facing away from the PCB circuit board 4 is a heat dissipation surface, that is, the top heat dissipation form is adopted for packaging, and the pins of the power tube 301 and the PCB circuit board 4 are welded to realize electrical connection; the heat sink 101 is fixedly connected to the PCB circuit board 4, and one or more cofferdam structures 102 are provided on the side of the heat sink 101 opposite to the heat dissipation surface of the power tube 301, and the bottom surface of the area surrounded by the cofferdam structure 102 is provided with a thermal interface material 2, and the thermal interface material 2 is used to fit with the heat dissipation surface of the power tube 301. After the heat sink 101 is fixedly connected to the PCB circuit board 4, the cofferdam structure 102 limits the thermal interface material 2 within the heat dissipation area of ​​the power tube 301, and at the same time, the thermal interface material 2 fits tightly with the heat dissipation surface of the power tube 301.

[0042] The power tube heat dissipation structure provided by the present invention, through the cofferdam structure 102 set on the radiator, confines the thermal conductive material inside the cofferdam, prevents the thermal conductive material from horizontal slippage and vertical flow under the influence of temperature changes and vibration factors, and improves the thermal reliability of the power supply device.

[0043] Specifically, the PCB circuit board 4 can be fixedly connected to the heat sink through the threaded connector 501, so that the power tube 301, the thermal interface material 2 and the heat sink are tightly fitted, and the cofferdam structure 102 confines the thermal interface material 2 within the area enclosed by it.

[0044] In a further embodiment, a heat-conducting insulating layer 103 is provided on the surface of the cofferdam structure 102, and the heat-conducting interface material 2 is provided outside the heat-conducting insulating layer 103, so that the power tube 301 is insulated from the heat sink body when it is attached to the heat sink for heat dissipation. By integrating the heat-conducting insulating layer 103 and the heat sink, there is no need to install additional insulating parts, which can simplify the manufacturing process and improve production efficiency.

[0045] In other embodiments, Figure 8 As shown, a thermally conductive insulating layer 103 may also be provided inside the heat sink, and formed into an integrated structure with the heat sink material by pressing or the like, with the exterior being a metal heat dissipation layer such as aluminum and aluminum alloy, copper and copper alloy, and the core being the thermally conductive insulating layer 103.

[0046] In a specific embodiment, Figures 2 to 4 As shown, the projection area B of the area enclosed by the cofferdam structure 102 is greater than or equal to the area A of the pin area of ​​the power tube 301, that is, the area enclosed by the cofferdam structure 102 is projected onto the mainboard, including the power tube 301 and the extended range of the power board tube pins, and the depth of the area enclosed by the cofferdam structure 102 is greater than or equal to 50 mm.

[0047] The thermally conductive insulating layer 103 disposed on the bottom surface of the cofferdam structure 102, that is, the thermally conductive insulating layer 103 disposed on the surface of the cofferdam structure 102, has a thickness ranging from 50 to 250 um, which can be selected according to actual conditions, and is preferably greater than or equal to 80 um.

[0048] In a further embodiment, the material of the thermally conductive insulating layer 103 is any one of Al2O3, AlN, Si3N4, PI, PEI, and epoxy resin composite materials.

[0049] In a further embodiment, the thermally conductive insulating layer 103 disposed on the surface of the cofferdam structure 102 is integrated with the heat sink by any one of the processing techniques of spraying, gluing, welding, hot pressing, and micro-arc oxidation.

[0050] In a further embodiment, the thermal interface material 2 is any one of a thermally conductive gel, a thermally conductive pad or a thermally conductive phase change material. The thickness of the thermal interface material 2 ranges from 150 to 500 mm, preferably from 150 to 350 mm. Too large a filling thickness of the thermally conductive material will increase the interface thermal resistance and affect the actual heat dissipation effect of the power supply device.

[0051] In a specific embodiment, the cofferdam structure 102 is specifically a groove provided on the lower surface of the heat sink 101, such as Figure 3 , 4 As shown, the groove can be formed by directly recessing the lower surface inwards, such as Figure 2 As shown, a circle of protrusions may also be provided, and the areas between the protrusions form a groove.

[0052] The angle between the side wall and the bottom surface around the groove is a right angle or an oblique angle, and there is no specific restriction. The side wall other than the bottom of the groove and the surface of other positions of the heat sink may or may not be provided with a thermal insulation layer 103, depending on the actual electrical insulation and structural processing requirements. In addition, there is no requirement for the number of cofferdam structures 102, which depends on the number of power tubes 301 that need to dissipate heat and the structural space and layout space.

[0053] The specific processing method of the cofferdam structure 102 is applicable to various embodiments, and can be formed by die-casting, machining, setting a cofferdam support frame (i.e., forming a protrusion) or dam glue (i.e., forming a protrusion).

[0054] There are two specific embodiments of the number of cofferdam structures 102 and power tubes 301, as follows:

[0055] In the first embodiment, if Figures 1 to 4 As shown, a cofferdam structure 102 is provided corresponding to each power tube 301 , that is, the power tube 301 corresponds to the cofferdam structure 102 one by one, and each power tube 301 can be adapted for installation.

[0056] In the second embodiment, if Figure 5 , 6 As shown, in order to improve the processing and production efficiency of the heat sink 101, multiple power tubes 301 share a cofferdam structure 102 as a whole, and the thermal interface material 2 is arranged on the surface of the thermal insulating coating of the cofferdam structure 102, and the multiple power tubes 301 are bonded to the thermal interface material 2 in a cofferdam structure 102.

[0057] In a further embodiment, Figure 6 As shown, considering the tolerance and PCB deformation problems when assembling multiple power tubes 301, it is necessary to assemble through threaded connectors 501 to ensure the thickness of the thermal conductive material and sufficient contact for heat dissipation. However, in some scenarios, due to the limitations of the waterway structure and the layout of the PCB circuit board 4, there is no extra space to set the threaded connector 501 mounting hole. In order to solve this problem, a support column 602 can be set at the position of the shell cover 601 corresponding to the power tube 301. When the shell cover 601 is installed (the shell cover 601 is connected to the shell or the edge of the heat exchanger through the threaded connector 501), the support column 602 presses down on the PCB circuit board 4, reduces the deformation and assembly gap of the PCB circuit board 4, controls the thickness of the thermal conductive material within a smaller range, and reduces the interface thermal resistance.

[0058] The present invention also provides a power supply device, comprising the above-mentioned power tube heat dissipation structure.

[0059] In a specific embodiment, the power supply device is an on-board charger, and the radiator is a shell water channel arranged in the shell of the on-board charger.

[0060] like Figure 7 As shown, for the heat dissipation structure described in the present invention, a mounting process manufacturing method is also proposed, including the steps of:

[0061] S101, firstly process the surface of the radiator structure to form a cofferdam structure;

[0062] S102, spraying a thermally conductive insulating layer on the surface of the cofferdam structure;

[0063] S103, applying a thermally conductive interface material at a position of the cofferdam structure with a thermally conductive insulating layer;

[0064] S104, assembling the PCB circuit board on which the power tube is assembled and the heat sink, so that the heat dissipation surface of the power tube is in full contact with the thermal interface material.

[0065] The specific embodiment of the installation process manufacturing method is as follows:

[0066] S101, a cofferdam structure is processed on the heat dissipation surface of the incoming structural parts of the radiator (including the shell water channel);

[0067] S102, spraying one or more layers of epoxy resin heat-conducting material on the surface of the cofferdam structure, and quickly curing it by UV to form a heat-conducting insulating layer on the surface of the radiator cofferdam structure;

[0068] S103, applying a thermally conductive gel material (i.e., a thermally conductive interface material) at the position of the cofferdam structure with the thermally conductive insulating layer, the material application process is not limited, dispensing is preferred, and steel screen printing can be selected;

[0069] S104, assembling the PCB circuit board assembled with the power tube and the housing such as the heat sink, so that the top heat dissipation surface of the power tube 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 tube through the cofferdam structure, and the interface thickness is ensured.

[0070] It should be noted that the terms used above are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0071] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0072] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the devices or elements referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention. The directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0073] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

Claims

1. A 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, characterized in that one side of the heat sink that is in contact with the heat dissipation surface of the power tube is provided with one or more cofferdam structures, a thermal interface material is arranged in the area enclosed by the cofferdam structure, and the heat dissipation surface of the power tube is in contact with the thermal interface material.

2. The power tube heat dissipation structure according to claim 1, characterized in that: The projection area B of the area enclosed by the cofferdam structure is ≥ the area A of the power tube pin area, and the depth of the area enclosed by the cofferdam structure is ≥ 50 mm.

3. The power tube heat dissipation structure according to claim 1, characterized in that: A heat-conducting insulating layer is arranged on the surface of the cofferdam structure.

4. The power tube heat dissipation structure according to claim 3, characterized in that: The thickness of the thermally conductive insulating layer is in the range of 50-250 um.

5. The power tube heat dissipation structure according to claim 3, characterized in that: The material of the thermally conductive insulating layer is any one of Al2O3, AlN, Si3N4, PI, PEI, and epoxy resin composite materials.

6. The power tube heat dissipation structure according to claim 3, characterized in that: The heat-conducting insulating layer arranged on the surface of the cofferdam structure is integrated with the heat sink through any one of the processing techniques of spraying, gluing, welding, hot pressing and micro-arc oxidation.

7. The power tube heat dissipation structure according to claim 1, characterized in that: The thermally conductive interface material is any one of a thermally conductive gel, a thermally conductive pad or a thermally conductive phase change material.

8. The power tube heat dissipation structure according to claim 1, characterized in that: The thickness of the thermal conductive interface material ranges from 150 to 500 mm.

9. The power tube heat dissipation structure according to claim 1, characterized in that: The cofferdam structure is a groove arranged on the surface of the radiator, and the angle between the side walls around the groove and the bottom surface is a right angle or an oblique angle.

10. The power tube heat dissipation structure according to claim 9, characterized in that: The cofferdam structure is formed by integral die-casting, machining, and setting a cofferdam support frame or cofferdam glue.

11. The power tube heat dissipation structure according to any one of claims 1 to 10, characterized in that: The cofferdam structures are arranged in one-to-one correspondence with the power tubes.

12. The power tube heat dissipation structure according to any one of claims 1 to 10, characterized in that: The plurality of power tubes are bonded to a thermally conductive interface material disposed in an area enclosed by a cofferdam structure.

13. The power tube heat dissipation structure according to claim 1, characterized in that: The PCB board is pressed by a support column arranged on the inner side of the cover plate of the power supply device housing, and the support column is directly opposite to the position where the power tube is arranged on the PCB board.

14. A power supply device, characterized in that: It comprises a power tube heat dissipation structure as described in any one of claims 1 to 13.

15. A processing and assembly method for a power tube heat dissipation structure, characterized in that: Includes steps: Processing the surface of the radiator structure to form a cofferdam structure; Spray a thermally conductive insulating layer on the surface of the cofferdam structure; Applying thermal interface material at the location of the cofferdam structure with the thermally conductive insulating layer; Assemble the PCB circuit board on which the power tube is assembled and the heat sink so that the heat dissipation surface of the power tube is in full contact with the thermal interface material.

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