Heat dissipation structure of MOS tube at bottom of PCB

Abstract

The utility model discloses a heat dissipation structure for MOS tubes at the bottom of a PCB, which comprises the PCB, MOS tubes are fixedly connected to two sides of the bottom of the PCB, the heat dissipation structure further comprises a heat dissipation bottom plate attached to the PCB, and a heat dissipation structure is arranged between the PCB and the heat dissipation bottom plate. After the PCB is installed and fixed, the MOS tube at the bottom of the PCB enters the groove of the heat dissipation bottom plate and extrudes the heat conduction joint mixture, meanwhile, the patch copper bar makes full contact with the heat conduction silica gel, part of heat emitted by the MOS tube in the working process is transmitted to the patch copper bar through the copper foil of the PCB, and then the patch copper bar transmits the heat to the heat dissipation bottom plate through the heat conduction silica gel pad. The other part of heat is transmitted to the heat dissipation bottom plate through the MOS tube plastic shell and the heat conduction joint mixture, the two heat dissipation ways are used for heat dissipation at the same time to achieve a good heat dissipation effect, and therefore the heat dissipation efficiency of the device is improved, the device is simple in structure and convenient to install, and the installation efficiency can be improved while the excellent heat dissipation effect is achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of AAA, especially a heat dissipation structure of MOS tube of PCB bottom. BACKGROUND

[0002] MOS tube, namely metal oxide semiconductor field effect transistor, plays a pivotal role in modern electronic equipment, especially in vehicle power supply products, the application of MOS tube is particularly key. The working principle of MOS tube is based on electric field effect, and the core part is a sandwich structure composed of a metal gate, an oxide insulating layer and a semiconductor channel. When a certain voltage is applied to the gate, an electric field will be formed at the interface between the semiconductor and the oxide, which will attract or repel free electrons in the channel, changing the conductivity of the channel. According to the different gate voltage, MOS tube can be in cut-off state, linear amplification zone or saturation conduction state. In vehicle power supply products, the heat dissipation structure of MOS tube is usually that the MOS tube is directly attached to the bottom surface of the shell or the MOS tube is attached to the side wall of the shell, and a heat-conducting insulating sheet or a ceramic sheet is placed between the MOS tube and the shell to achieve the effect of insulation and heat conduction. Both of these two heat dissipation structures need to fix the MOS tube with screws, or use screws to fix the MOS tube with MOS tube pressing strip, or use a clasp spring pressing plate to fix the MOS tube.

[0003] The conventional heat dissipation structure of the two MOS tubes needs to fix the MOS tube with screws or a clasp spring pressing plate, and the installation efficiency of such heat dissipation structure is low and the installation is cumbersome.

[0004] In the Chinese patent document with publication number CN117998819A, a controller MOS tube heat dissipation structure is disclosed, which includes a heat dissipation base, a shell and a circuit board. The heat dissipation base is provided with a plurality of first extrusion pieces on the side facing the shell. The shell is provided with a plurality of second extrusion pieces on the side facing the heat dissipation base. The first extrusion pieces are provided with elastic heat-conducting gaskets on the side facing the MOS tube. When the shell and the heat dissipation base are assembled in place, the elastic heat-conducting gaskets and the second extrusion pieces are respectively located on the two sides of the MOS tube in the horizontal direction and the second extrusion pieces extrude the MOS tube to tightly contact the elastic heat-conducting gaskets. The shell adopts a heat-conducting shell, the second extrusion pieces are in heat-conducting connection with the shell, the side of the MOS tube contacting the second extrusion pieces is provided with heat-conducting grease, and the MOS tube and the heat dissipation base are connected through the compressed heat-conducting silica gel gasket to form an effective and reliable heat-conducting channel, thereby ensuring the heat dissipation effect of the MOS tube. The heat dissipation structure is assembled in place with the shell and the heat dissipation base, but the volume of the controller MOS tube heat dissipation structure is large and occupies more installation space.

[0005] The existing heat dissipation structure of MOS tube needs to fix the MOS tube with screws or a clasp spring pressing plate, and the installation efficiency of such heat dissipation structure is low and the installation is cumbersome.

[0006] In order to solve the above problems existing in the prior art, it is a problem worth studying to provide a heat dissipation structure of a MOS tube at the bottom of a PCB. Content of the utility model

[0007] The utility model discloses a heat dissipation structure of a MOS tube at the bottom of a PCB, which realizes the technical effects of efficient installation and rapid heat dissipation.

[0008] The utility model discloses a heat dissipation structure of a MOS tube at the bottom of a PCB, which realizes the technical effects of efficient installation and rapid heat dissipation.

[0009] A heat dissipation structure of a MOS tube at the bottom of a PCB, comprising a PCB board, both sides of the bottom of the PCB board are fixedly connected with MOS tubes, further comprising a heat dissipation bottom plate arranged in close contact with the PCB board, and a heat dissipation structure is arranged between the PCB board and the heat dissipation bottom plate.

[0010] The heat dissipation structure comprises grooves arranged at the top of both sides of the heat dissipation bottom plate, the positions and shapes of the grooves are matched with the positions and shapes of the MOS tubes, so that the heat dissipation device and the PCB board can be stably arranged in close contact, and the stability of the device is improved.

[0011] The heat dissipation structure further comprises a patch copper strip fixedly connected to the surface of the PCB board, the patch copper strip is located at the outer side of the MOS tube, the surface of the patch copper strip is provided with a heat-conducting silica gel pad, the other side of the heat-conducting silica gel pad is in contact with the surface of the heat dissipation bottom plate, the patch copper strip absorbs part of the heat generated by the MOS tube, and the heat is transferred to the heat dissipation bottom plate through the heat-conducting silica gel pad, so that the heat dissipation bottom plate can assist in rapid heat dissipation.

[0012] The MOS tube and the patch copper strip are both welded and fixed to the surface of the PCB board.

[0013] The heat dissipation structure further comprises a heat-conducting caulking agent filled in the grooves, the heat-conducting caulking agent is located in the gap between the MOS tube and the groove, the device has a simple structure and is convenient to install, can have excellent heat dissipation effect, and can improve the installation efficiency.

[0014] BOSS columns are arranged at the four corners and the center of the heat dissipation bottom plate, round holes are arranged at the four corners and the center of the PCB board, the positions of the BOSS columns and the round holes are matched, and screws are screwed into the BOSS columns and the round holes, so that the PCB board and the MOS tube are fixedly connected through the screws, the MOS tube does not need to be additionally fixed, and before the PCB board is installed, the heat-conducting caulking agent needs to be coated in the grooves of the heat dissipation bottom plate, and the heat-conducting silica gel pad needs to be placed at the position corresponding to the MOS tube on the bottom plate, so that the installation and fixation of the MOS tube can be completed after the PCB board is screwed tightly.

[0015] 1. The heat dissipation structure of the MOSFET at the bottom of the PCB: The MOSFET in this technical solution does not require additional fixing. Before the PCB is installed, thermally conductive sealant is applied to the groove of the heat dissipation base plate, and thermally conductive silicone pads are placed at the corresponding positions of the MOSFETs on the base plate. After the PCBA is tightened with screws, the installation and fixing of the MOSFETs can be completed. The installation efficiency of the product is significantly improved, and the structure and operation steps are simpler.

[0016] 2. The heat dissipation structure of the MOSFET at the bottom of the PCB: During operation, the heat generated by the MOSFET is partially transferred to the surface-mount copper strip through the copper foil of the PCB, and then transferred to the heat dissipation base plate through the thermally conductive silicone pad. The other part of the heat is transferred to the heat dissipation base plate through the MOSFET's plastic shell and the thermally conductive sealant. The two heat dissipation paths are used simultaneously to achieve better heat dissipation effect, thereby improving the heat dissipation efficiency of the device. Moreover, the device has a simple structure and is easy to install. While having excellent heat dissipation effect, it can also improve installation efficiency.

[0017] 3. The heat dissipation structure of the MOSFET at the bottom of the PCB has a groove on the heat dissipation base plate. When the PCB board and the heat dissipation base plate are attached, the MOSFET can be retracted into the groove, avoiding interference from the MOSFET that would prevent the PCB board and the heat dissipation base plate from being fully attached. The cooperation between the groove and the MOSFET ensures that the surfaces of the PCB board and the heat dissipation base plate can be fully attached. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the PCB board structure of this utility model;

[0019] Figure 2 This is a schematic diagram of the structure of the heat dissipation base plate of this utility model;

[0020] Figure 3 This is a cross-sectional structural diagram of the present invention in its assembled state;

[0021] Figure 4 This utility model Figure 3 A magnified structural diagram of point A in the middle.

[0022] In the diagram: 1-PCB board, 2-MOSFET, 3-heat sink base plate, 4-groove, 5-surface copper strip, 6-thermal conductive silicone pad, 7-thermal conductive sealant, 8-BOSS pillar, 9-round hole, 10-screw. Detailed Implementation

[0023] The embodiments of this utility model are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model. Example 1

[0024] like Figures 1 to 4 As shown, a heat dissipation structure for a MOSFET at the bottom of a PCB includes a PCB board 1, with MOSFETs 2 fixedly connected to both sides of the bottom of the PCB board 1, and a heat dissipation base plate 3 that is attached to the PCB board 1. A heat dissipation structure is provided between the PCB board 1 and the heat dissipation base plate 3.

[0025] like Figure 1 As shown, the heat dissipation structure includes grooves 4 on both sides of the top of the heat dissipation base plate 3. The position and shape of the grooves 4 are adapted to the position and shape of the MOSFET 2. By opening grooves 4 on the heat dissipation base plate 3, the MOSFET can be retracted into the grooves 4 when the PCB board 1 is attached to the heat dissipation base plate 3, avoiding interference from the MOSFET that would cause the PCB board 1 and the heat dissipation base plate 3 to not be fully attached. The matching relationship between the grooves 4 and the MOSFET 2 allows the surfaces of the PCB board 1 and the heat dissipation base plate 3 to be fully attached. The PCB board 1 directly transfers some of the heat generated during operation to the heat dissipation base plate 3, improving the heat dissipation efficiency of the device and ensuring that the heat dissipation device and the PCB board are stably attached, thus improving the stability of the device.

[0026] like Figures 1 to 4 As shown, the heat dissipation structure also includes a surface-mount copper strip 5 fixedly connected to the surface of the PCB board 1. The surface-mount copper strip 5 is located on the outside of the MOSFET 2. A thermally conductive silicone pad 6 is provided on the surface of the surface-mount copper strip 5. The other side of the thermally conductive silicone pad 6 is in contact with the surface of the heat dissipation base plate 3. By setting the surface-mount copper strip 5 and the thermally conductive silicone pad 6 between the PCB board 1 and the heat dissipation base plate 3, the surface-mount copper strip 5 absorbs part of the heat generated by the MOSFET 2, and the thermally conductive silicone pad 6 conducts heat to the heat dissipation base plate 3, which assists in rapid heat dissipation.

[0027] Both the MOSFET 2 and the surface-mount copper strip 5 are soldered and fixed to the surface of the PCB board 1.

[0028] like Figures 1 to 4As shown, the heat dissipation structure also includes thermally conductive sealant 7 filled inside the groove 4. The thermally conductive sealant 7 is located in the gap between the MOSFET 2 and the groove 4. Before the PCB board 1 is installed and fixed, the thermally conductive sealant 7 is filled into the groove 4 of the heat dissipation base plate 3, and thermally conductive silicone pads 6 are placed at corresponding positions on the surface mount copper strips 5. After the PCB board 1 is installed and fixed, the MOSFET 2 at the bottom of the PCB board 1 enters the groove 4 of the heat dissipation base plate 3 and compresses the thermally conductive sealant 7. The thermally conductive sealant 7 is paste-like inside the groove 4, allowing the top surface of the MOSFET 2's plastic shell to fully contact the thermally conductive sealant 7. Simultaneously, the surface mount copper strips 5... Strip 5 compresses the thermally conductive silicone pad 6 (which is relatively soft and compressible), allowing for full contact with the thermally conductive silicone pad 6. During operation, the heat generated by the MOSFET 2 is partially transferred through the copper foil of the PCB board 1 to the surface-mount copper strip 5, which then transfers the heat through the thermally conductive silicone pad 6 to the heat sink base plate 3. The other part of the heat is transferred through the MOSFET's plastic shell to the thermally conductive sealant 7 and then to the heat sink base plate 3. The simultaneous dissipation of heat through these two pathways achieves a better heat dissipation effect, thereby improving the heat dissipation efficiency of the device. Furthermore, this device has a simple structure and is easy to install, improving installation efficiency while providing excellent heat dissipation. Example 2

[0029] like Figures 1 to 3 As shown, BOSS posts 8 are provided at the four corners and center of the heat sink base plate 3, and round holes 9 are provided at the four corners and center of the PCB board 1. The positions of the BOSS posts 8 and round holes 9 are matched, and screws 10 are threaded into the BOSS posts 8 and round holes 9. The PCB board 1 and MOSFET 2 are fixedly connected by screws 10. By setting round holes 9 and BOSS posts 8 on the PCB board 1 and the heat sink base plate 3 respectively, and using screws 10 to thread into the round holes 9 and BOSS posts 8, the PCB board 1 can be fixed to the heat sink base plate 3, thus completing the PCB board 1... Compared to existing MOSFET heat dissipation structures that require screws to fix the MOSFET, or the use of screws with MOSFET clamps, or the use of spring clips to fix the MOSFET, this technical solution eliminates the need for additional fixing of the MOSFET. Before installation on the PCB1, simply apply thermally conductive sealant to the groove of the heat dissipation base plate, place a thermally conductive silicone pad at the corresponding position of the MOSFET on the base plate, and tighten the screws on the PCBA to complete the installation and fixation of the MOSFET. This significantly improves the installation efficiency of the product, and simplifies the structure and operation steps.

[0030] The working principle of this utility model is as follows:

[0031] S1. Before the PCB board 1 is installed and fixed, fill the groove 4 of the heat sink base plate 3 with thermally conductive sealant 7 and place the thermally conductive silicone pad 6 at the corresponding position of the patch copper strip 5.

[0032] S2, the MOS tube is aligned with the position of the groove, and is screwed with the round hole 9 and the BOSS column 8, that is, the PCB board 1 is fixed on the heat dissipation bottom plate 3, and the cooperation and installation of the PCB board 1 and the heat dissipation structure are completed;

[0033] S3, after the PCB board 1 is installed and fixed, the MOS tube 2 at the bottom of the PCB board 1 enters the groove 4 of the heat dissipation bottom plate 3 and extrudes the heat-conducting filling agent 7, the heat-conducting filling agent 7 is paste-like in the groove 4, the plastic shell top surface of the MOS tube 2 can be in full contact with the heat-conducting filling agent 7, at the same time, the patch copper strip 5 extrudes the heat-conducting silica gel pad 6 (relatively soft and compressible) and can be in full contact with the heat-conducting silica gel 6, the heat generated by the MOS tube 2 in the working process is partly transmitted to the patch copper strip 5 through the copper foil of the PCB board 1, the patch copper strip 5 further transmits the heat to the heat dissipation bottom plate 3 through the heat-conducting silica gel pad 6, and the other part of the heat is transmitted to the heat dissipation bottom plate 3 through the MOS tube plastic shell to the heat-conducting filling agent 7, two heat dissipation ways simultaneously dissipate heat to achieve better heat dissipation effect, thereby improving the heat dissipation efficiency of the device, and the device has simple structure and convenient installation, can improve the installation efficiency while having excellent heat dissipation effect.

Claims

1. A heat dissipation structure of a PCB bottom MOS tube, comprising a PCB plate (1), the bottom of the PCB plate (1) is fixedly connected with MOS tubes (2) on both sides, characterized in that: It also includes a heat dissipation base plate (3) which is attached to the PCB plate (1), and a heat dissipation structure is arranged between the PCB plate (1) and the heat dissipation base plate (3).

2. The heat dissipation structure of a PCB bottom MOS transistor according to claim 1, wherein: The heat dissipation structure includes grooves (4) which are opened on both sides of the top of the heat dissipation base plate (3), and the position and shape of the grooves (4) are matched with the position and shape of the MOS tube (2).

3. The heat dissipation structure of a PCB bottom MOS transistor according to claim 2, characterized in that: The heat dissipation structure also includes a patch copper strip (5) which is fixedly connected to the surface of the PCB plate (1), and the patch copper strip (5) is located outside the MOS tube (2), and the surface of the patch copper strip (5) is provided with a heat-conducting silica gel pad (6), and the other side of the heat-conducting silica gel pad (6) is in contact with the surface of the heat dissipation base plate (3).

4. The heat dissipation structure of a PCB bottom MOS transistor according to claim 3, characterized in that: The MOS tube (2) and the patch copper strip (5) are both welded and fixed to the surface of the PCB plate (1).

5. The heat dissipation structure of a PCB bottom MOS transistor according to claim 2, wherein: The heat dissipation structure also includes a heat-conducting filling agent (7) which is filled in the grooves (4), and the heat-conducting filling agent (7) is located in the gap between the MOS tube (2) and the grooves (4).

6. The heat dissipation structure of a PCB bottom MOS transistor according to claim 1, wherein: BOSS columns (8) are arranged at the four corners and the center of the heat dissipation base plate (3), circular holes (9) are opened at the four corners and the center of the PCB plate (1), the positions of the BOSS columns (8) and the circular holes (9) are matched, screws (10) are threadedly connected in the BOSS columns (8) and the circular holes (9), and the PCB plate (1) and the MOS tube (2) are fixedly connected through the screws (10).

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