Heat dissipation structure of MOS (Metal Oxide Semiconductor) tube

Abstract

The utility model relates to an MOS tube heat radiation structure. An MOS tube heat dissipation structure comprises a shell and an elastic piece, the shell is provided with a heat dissipation contact face used for making contact with MOS tubes, the shell is provided with a first fixing hole used for fixing a circuit board, the elastic piece comprises a connecting part and a plurality of elastic piece bodies which are located on the same side of the connecting part and arranged side by side, and one MOS tube corresponds to one elastic piece body. A fixing block is fixed on one side, provided with the heat dissipation contact surface, of the shell through a fastener, the fixing block and the shell are fixed so that the elastic sheet can be limited between the MOS tube and the fixing block, the fixing block is provided with a fixing block matching surface, and the fixing block and the shell are both provided with second fixing holes used for being matched with the fastener. And the circuit board is provided with an abdicating space corresponding to the second fixing hole. The utility model has the advantages that the MOS tube can be welded first and then pressed, and the heat dissipation effect of the MOS tube can be ensured.

Description

Technical Field

[0001] The utility model relates to a MOS tube heat dissipation structure. Background Art

[0002] The MOS tube of a conventional controller is welded and fixed on the circuit board. Since power devices such as MOS tubes generate a lot of heat, a heat sink such as an aluminum block is set up to achieve heat transfer by making the MOS tube close to the heat sink. To ensure the efficiency of heat transfer, a spring strip is used to press the MOS tube against the heat sink to ensure effective contact and heat transfer efficiency.

[0003] In the on-board charger, in order to further improve the heat dissipation effect, an aluminum shell is provided with a water-cooling cavity inside the shell; in order to facilitate assembly, the MOS tube is first welded to the circuit board, and then the circuit board is fixed to the aluminum shell, which makes it inconvenient to achieve a tight contact between the MOS tube and the heat dissipation part of the aluminum shell. Utility Model Content

[0004] The utility model aims to provide a MOS tube heat dissipation structure which is convenient for welding the MOS tube first and then pressing the MOS tube and can ensure the heat dissipation effect of the MOS tube.

[0005] To achieve the above-mentioned purpose, the utility model adopts the following technical scheme: a MOS tube heat dissipation structure, comprising a shell and a spring sheet, the shell being provided with a heat dissipation contact surface for contacting the MOS tube, the shell being provided with a first fixing hole for fixing a circuit board, the spring sheet comprising a connecting portion and a plurality of spring sheet bodies arranged side by side and located on the same side of the connecting portion, one MOS tube corresponding to one spring sheet body, a fixing block being fixed by a fastener on one side of the shell being provided with the heat dissipation contact surface, the fixing block being fixed to the shell so that the spring sheet is restricted between the MOS tube and the fixing block, the fixing block being provided with a fixing block mating surface, the fixing block mating surface gradually extending from one end to the other end along the installation direction of the fastener away from the heat dissipation contact surface side, the fixing block and the shell being provided with a second fixing hole for mating with the fastener, and a clearance space being provided at the circuit board corresponding to the second fixing hole.

[0006] First, weld the MOS transistor to the circuit board, and place the fixing block and the elastic piece on the housing, making the elastic piece lean against the fixing block. Then, successively insert the fastener bolt into the second fixing holes of the fixing block and the housing (without tightening the fastener). Next, align and install the circuit board with the housing so that the MOS transistor on the circuit board is inserted between the elastic piece body of the elastic piece and the heat dissipation contact surface of the housing. Pass the screwdriver through the relief space of the circuit board, extend the screwdriver into the space formed by the housing and the circuit board and align it with the fastener bolt, and tighten the fastener. As the fastener is screwed in, the fixing block is pressed downward, and the mating surface of the fixing block will gradually move downward, causing the elastic piece to move toward the MOS transistor side and deform, thereby realizing the pressing of the MOS transistor.

[0007] The utility model facilitates the fixing of the fixing block and the elastic piece after the installation of the circuit board is completed, so that the MOS transistor can be welded to the circuit board first and then the elastic piece can be pressed, which is applicable to the heat dissipation of MOS transistors in products such as in-vehicle chargers that are not easy to assemble.

[0008] Preferably, a bending portion is provided at a position where the elastic piece body deviates from the connecting portion, and a bending portion mating surface for mating with the mating surface of the fixing block is formed at the bending portion. The bending portion mating surface gradually extends away from the heat dissipation contact surface side from the end of the elastic piece body to the root of the elastic piece body.

[0009] As the fastener is tightened, the fixing block will be pressed down by the head of the fastener bolt, and the mating surface of the fixing block will exert a force on the bending portion mating surface of the elastic piece, causing the elastic piece body to deform and move toward the heat dissipation contact surface side. In the above way, the fixing of the fixing block and the elastic piece can be made more convenient.

[0010] Preferably, a positioning groove and a positioning portion extending into the positioning groove are provided between the housing and the fixing block, and the elastic piece is located between the heat dissipation contact surface and the positioning groove or the positioning portion. By providing the mutually cooperating positioning portion and positioning groove, the relative position between the heat dissipation contact surfaces of the fixing block and the housing is determined, ensuring the pressing effect of the fixing block on the elastic piece.

[0011] Preferably, the fixing block has a downward-extending limiting protrusion, and when the fixing block is fixed to the housing, the limiting protrusion is located between adjacent elastic piece monomers. The position of the elastic piece is further limited by the limiting protrusion to prevent the elastic piece from being misaligned and ensure the pressing effect of the elastic piece body of the elastic piece on the MOS transistor.

[0012] Preferably, a first mating groove is provided on the housing, and the connecting portion of the elastic piece is located in the first mating groove. The first mating groove can be used for positioning the connecting portion of the elastic piece, facilitating the placement and erection of the elastic piece.

[0013] Preferably, the width of the first fitting groove is greater than the thickness of the connecting portion. The above setting enables the connecting portion of the elastic sheet to be inclined or bent in the first fitting groove, thereby reducing the assembly difficulty of the elastic sheet and being more adaptable to different assembly conditions.

[0014] Preferably, the connecting portion has a plurality of extending portions extending to the same side. When the connecting portion of the elastic sheet is located in the fitting groove, the end portions of the extending portions are supported on the lateral groove wall of the fitting groove and are close to the MOS transistor.

[0015] The extending portions are supported on the groove wall of the fitting groove during assembly, enabling the elastic sheet to have a rebounding effect, which helps to improve the contact stability between the elastic sheet body and the MOS transistor.

[0016] Preferably, the housing is provided with a second fitting groove for positioning the MOS transistor. When the MOS transistor is located in the second fitting groove, the MOS transistor is located between the groove walls on the opposite sides of the second fitting groove.

[0017] By providing the second fitting groove to position the MOS transistor, the relative position between the elastic sheet body and the MOS transistor can be ensured.

[0018] Preferably, the elastic sheet body is provided with a slotted opening extending along its own length direction. By providing the slotted opening, the flexibility of the elastic sheet during use can be improved, which is applicable to different assembly conditions and avoids excessive pressing of the MOS transistor.

[0019] Preferably, the end portion of the elastic sheet body extends towards the side away from the heat dissipation contact surface. Through the above setting, when aligning and assembling the circuit board and the housing, it is convenient for the MOS transistor to be squeezed between the elastic sheet and the heat dissipation contact surface.

[0020] The utility model has the advantages of facilitating the soldering and then pressing of the MOS transistor and ensuring the heat dissipation effect of the MOS transistor. Description of the Drawings

[0021] Figure 1 It is a schematic structural diagram of the utility model.

[0022] Figure 2 It is a schematic structural diagram when the fixing block, the housing and the elastic sheet of the utility model are matched.

[0023] Figure 3 It is a schematic structural diagram of the first fitting groove of the housing of the utility model.

[0024] Figure 4 It is a schematic structural diagram of the fixing block of the utility model.

[0025] Figure 5 It is a schematic structural diagram of the elastic sheet of the utility model. Detailed Description of the Invention

[0026] The utility model is further described below based on the accompanying drawings and specific embodiments.

[0027] Depend on Figures 1 to 5 As shown, this embodiment discloses a MOS tube heat dissipation structure, including a housing 100 and a spring 2, the housing 100 is provided with a heat dissipation contact surface 11 for contacting the MOS tube 31, the housing 100 is provided with a first fixing hole for fixing the circuit board 3, the spring 2 includes a connecting portion 21 and three spring bodies 22 arranged side by side on the same side of the connecting portion 21, in this embodiment, each spring 2 corresponds to three MOS tubes 31, and each MOS tube 31 corresponds to one spring body 22. Among them, a heat dissipation ceramic sheet is provided at the heat dissipation contact surface 11, and when the MOS tube 31 is pressed against the heat dissipation contact surface 11, the surface of the MOS tube 31 is in contact with the ceramic sheet.

[0028] The housing 100 is provided with a first matching groove 102 for accommodating the connecting portion 21 of the spring 2, and the width of the matching groove 102 is greater than the thickness of the connecting portion 21. The connecting portion 21 has a convex extension portion 211 extending to the same side. When the connecting portion 21 of the spring 2 is located in the matching groove 102, the end of the extension portion 211 is supported on the lateral groove wall of the matching groove 102 and close to the MOS tube 31.

[0029] The housing 100 is provided with a second matching groove 103 for positioning the MOS tube 31. The cross-sectional shape of the second matching groove 103 is the same as the cross-sectional outer edge shape of the MOS tube 31. When the MOS tube 31 is located in the second matching groove 103, the MOS tube 31 is located between the groove walls on the opposite sides of the second matching groove 103. The second matching groove 103 of this embodiment is arranged on the assembly block 104, and the assembly block 104 is fixed on the housing 100.

[0030] The housing 100 is provided with a fixing block 4 fixed to one side of the heat dissipation contact surface 11 through a fastener 40. The fastener 40 in this embodiment is a bolt. The fixing block 4 is fixed to the housing 100 so that the spring piece 2 is confined between the MOS tube 31 and the fixing block 4. The fixing block 4 and the housing 100 are both provided with a second fixing hole 401 for matching the fastener 40, and a clearance space 30 is provided at the circuit board 3 corresponding to the second fixing hole 40.

[0031] The fixing block 4 has a fixing block mating surface 41, which gradually extends from bottom to top and from one end to the other end toward the side close to the heat dissipation contact surface 11. The spring body 22 has a bent portion 20 at a position deviating from the connection portion. The upper side of the bent portion 20 constitutes a bent portion mating surface 221 for mating with the fixing block mating surface 41. The bent portion mating surface 221 gradually extends away from the heat dissipation contact surface 11 from the end (upper end) of the spring body 22 to the root (lower end) of the spring body 22. The spring body 22 is provided with a slot 221 extending along its length direction, and the slots 221 are provided on both the upper and lower sides of the bent portion 20. The upper end of the spring body 22 extends away from the heat dissipation contact surface 11.

[0032] The fastener 40 is passed through the fixing block 4 and extended into the second fixing hole of the housing 100, and the fastener 40 is spirally rotated. The fixing block mating surface 41 contacts the bending portion mating surface 221. As the fastener 40 is tightened, the fixing block 4 continues to move downward and causes the spring body 22 to be forced to move toward the MOS tube side, thereby clamping the MOS tube 31 between the heat dissipation contact surface 11 and the spring body 22.

[0033] The housing 100 has a positioning portion 101 extending upward, and the fixing block 4 is provided with a positioning groove for cooperating with the positioning portion 101 on the side away from the heat dissipation contact surface 11, so that the fixing block 4 only needs one fastener 40 to determine the fixed position; the fixing block 4 has a limiting protrusion 43 extending downward. After the assembly of the spring sheet 2 and the fixing block 4 is completed, the spring sheet 2 is located between the heat dissipation contact surface 11 and the positioning portion 101, the limiting protrusion 43 is located between two adjacent spring sheet monomers 22, and the lower end of the limiting protrusion 43 is close to the connecting portion 21.

[0034] Place the fixing block 4 and the spring sheet 2 on the shell 100, extend the fastener bolts into the fixing block 4 and the second fixing holes of the shell 100 in turn (do not tighten the fasteners), and place the spring sheet 2 in the first matching groove 102. Since the spring sheet 2 is not elastically deformed at this time, the fixing block 4 will be supported on the spring sheet 2, and the fixing block matching surface 41 of the fixing block 4 will be supported on the matching surface 221 of the bent portion of the spring sheet 2.

[0035] Then, the circuit board 3 and the housing 100 are aligned and installed so that the MOS tube 31 on the circuit board 3 is inserted between the spring body 22 of the spring 2 and the ceramic plate at the heat dissipation contact surface 11 of the housing 100, and the screwdriver is passed through the clearance space 30 of the circuit board 3. The fastener 40 is rotated by the screwdriver. As the fastener 40 is screwed in, the fixing block 4 is pressed downward, the spring body 22 is compressed and bent, and the end of the spring body 22 moves toward the MOS tube 31 and deforms, thereby achieving the pressing of the MOS tube 31.

Claims

1. A MOS tube heat dissipation structure, comprising a shell and a spring, wherein the shell is provided with a heat dissipation contact surface for contacting the MOS tube, and the shell is provided with a first fixing hole for fixing a circuit board, characterized in that: The spring sheet includes a connecting portion and a plurality of spring sheet bodies arranged side by side on the same side of the connecting portion, one MOS tube corresponds to one spring sheet body, a fixing block is fixed to one side of the shell provided with a heat dissipation contact surface through a fastener, the fixing block is fixed to the shell so that the spring sheet is restricted between the MOS tube and the fixing block, the fixing block has a fixing block mating surface, the fixing block mating surface gradually extends away from the heat dissipation contact surface from one end to the other end along the installation direction of the fastener, the fixing block and the shell are both provided with a second fixing hole for mating with the fastener, and a clearance space is provided on the circuit board corresponding to the second fixing hole.

2. The MOS tube heat dissipation structure according to claim 1, characterized in that: The spring sheet body has a bent portion at a position deviating from the connection portion, and the bent portion constitutes a bent portion mating surface for mating with the mating surface of the fixing block, and the bent portion mating surface gradually extends from the end of the spring sheet body to the root of the spring sheet body away from the heat dissipation contact surface.

3. The MOS tube heat dissipation structure according to claim 1, characterized in that: A positioning groove and a positioning portion extending into the positioning groove that cooperate with each other are provided between the shell and the fixing block, and the spring sheet is located between the heat dissipation contact surface and the positioning groove or the positioning portion.

4. The MOS tube heat dissipation structure according to claim 1, characterized in that: The fixing block has a limiting protrusion extending downwards. When the fixing block is fixed to the housing, the limiting protrusion is located between two adjacent elastic sheet monomers.

5. The MOS tube heat dissipation structure according to claim 1 or 4, characterized in that: The housing is provided with a first matching groove, and the connecting portion of the spring sheet is located in the first matching groove.

6. The MOS tube heat dissipation structure according to claim 5, characterized in that: The width of the matching groove is greater than the thickness of the connecting portion.

7. The MOS tube heat dissipation structure according to claim 5, characterized in that: The connecting portion has a plurality of extension portions extending toward the same side. When the connecting portion of the spring sheet is located in the matching groove, the end of the extension portion is supported on the lateral groove wall of the matching groove and is close to the MOS tube.

8. The MOS tube heat dissipation structure according to claim 1, characterized in that: The housing is provided with a second matching groove for positioning the MOS tube. When the MOS tube is located in the second matching groove, the MOS tube is located between groove walls on two opposite sides of the second matching groove.

9. The MOS tube heat dissipation structure according to claim 1, characterized in that: The spring sheet body is provided with a slot extending along its length direction.

10. The MOS tube heat dissipation structure according to claim 1, characterized in that: The end of the spring body extends away from the heat dissipation contact surface.

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