MOS transistor single tube fixing structure and fixing method

Abstract

The application discloses a MOS tube single tube fixing structure and a fixing method, relates to the technical field of MOS tube single tube fixing structure, and comprises a PCB board, a fixing assembly, a MOS tube and a radiator, wherein the fixing assembly comprises a first connecting part, a second connecting part and a fixing member, the first connecting part is arranged on the side of the fixing member adhering to the PCB board, the first connecting part is connected with the PCB board through clamping, one end of the second connecting part is arranged on the side of the fixing member facing the radiator, the other end of the side of the fixing member facing the radiator is further provided with a positioning groove, the first connecting part is located between the second connecting part and the positioning groove, the MOS tube is clamped in the positioning groove and adheres to the radiator, the pin of the MOS tube is fixedly connected with the PCB board, and the fixing assembly, the MOS tube and the radiator are connected and fixed through fasteners, compared with the prior art, the use of fasteners is reduced, the relevant structure is optimized, the MOS tube is prevented from being damaged during installation, meanwhile, installation is more convenient, and production efficiency is effectively improved.

Description

Technical Field

[0001] This invention relates to the field of single-tube fixing structure technology for MOS transistors, and particularly to a single-tube fixing structure and fixing method for MOS transistors. Background Technology

[0002] Mounting MOSFETs on the PCB board inside the inverter requires a high-precision mounting structure. Existing methods for mounting MOSFETs on the PCB board include: directly fixing the MOSFETs with screws or fixing a pressure plate with screws, and then securing the MOSFETs to the pressure plate. Currently, screw mounting is widely used, but it suffers from problems such as unreliable MOSFET mounting and low strength, affecting product lifespan. While some methods use pressure plates or other mounting structures, the number of screws increases installation costs. Furthermore, the use of multiple bolts makes installation cumbersome and hinders rapid PCB board assembly. Moreover, if the screw depth is not effectively controlled, it can easily damage the MOSFETs. Summary of the Invention

[0003] The present invention aims to at least partially solve one of the aforementioned technical problems in the prior art. To this end, embodiments of the present invention provide a single-tube fixing structure for a MOSFET, reducing the use of fasteners, optimizing the related structure, avoiding damage to the MOSFET during installation, and simultaneously making installation more convenient and effectively improving production efficiency.

[0004] This invention also provides a method for fixing a single MOS transistor using the above-described single-transistor fixing structure.

[0005] According to an embodiment of the first aspect of the present invention, a single-transistor fixing structure for a MOSFET is provided, comprising a PCB board, a fixing assembly, a MOSFET, and a heat sink arranged sequentially, wherein...

[0006] The fixing component includes a first connecting part, a second connecting part, and a fixing member capable of deformation. The first connecting part is disposed on the side of the fixing member that is in contact with the PCB board and is snapped into the PCB board. The second connecting part is disposed at one end of the fixing member facing the heat sink, and the other end of the fixing member facing the heat sink is also provided with a positioning groove. The first connecting part is located between the second connecting part and the positioning groove.

[0007] The MOS transistor is inserted into the positioning slot and fits against the heat sink, and the pins of the MOS transistor are fixedly connected to the PCB board.

[0008] It also includes fasteners, which pass through the first connecting part and the fixing member in sequence. One end of the fastener presses against the fixing member, and the other end is threaded to the heat sink. When the end of the fastener is screwed into the heat sink, the middle part of the fixing member deforms towards the heat sink under the action of the fastener, so that the second connecting part abuts against the heat sink, and the fixing member presses the MOS transistor against the heat sink.

[0009] The aforementioned single-tube fixing structure for MOSFETs has at least the following advantages: During assembly, the MOSFET is pressed into the positioning groove and adjusted to be flush with the second connecting part. After the first connecting part is snapped onto the PCB board, the fixing component is pressed to make the fixing component fit against the PCB board. At this time, because the first connecting part is snapped onto the PCB board, the entire fixing component cannot rotate. Simultaneously, due to the presence of the positioning groove, the MOSFET is well positioned and fixed. When the fixing component fits against the PCB board, the pins of the MOSFET are accurately positioned at the corresponding soldering positions on the PCB board, facilitating subsequent batch soldering of the MOSFET pins onto the PCB board without additional position adjustments. After the above operations are completed, the fastener is passed through the first connecting part and the fixing component in sequence. One end of the fastener presses against the fixing component, and the other end is threaded to the heat sink. When the end of the fastener is screwed into the heat sink, the middle part of the fixing component deforms towards the heat sink under the action of the fastener, so that the second connecting part abuts against the heat sink. The end of the fixing component away from the second connecting part presses the MOSFET against the heat sink under the force generated by the deformation. Regardless of the tightness of the fastener, it can ensure that the MOSFET and the heat sink are completely in contact, effectively improving the heat dissipation efficiency. At the same time, because the fixing component can produce elastic deformation, even if the fastener is over-tightened, there will be no excessive clamping force that could damage the MOSFET. Compared with the existing technology, while ensuring a stable connection, it reduces the use of fasteners, optimizes the clamping and installation methods, makes installation simpler, eliminates the positioning and adjustment steps, effectively improves the installation efficiency of the MOSFET, extends the service life of the product, and facilitates subsequent disassembly and maintenance.

[0010] According to the first aspect embodiment of the present invention, the fixing member first extends horizontally to form a straight section, then extends downward at an incline to form a first incline section, and then extends upward at an incline to form a second incline section. The protruding end formed by the first incline section and the second incline section becomes the bottom of the positioning groove. The straight section is attached to the PCB board. The first connecting part is disposed on one side of the straight section, and the second connecting part is disposed on the other side of the straight section.

[0011] According to the MOS transistor single-tube fixing structure of the first aspect embodiment of the present invention, the first inclined section has first stops extending on both sides in a direction perpendicular to the straight section, and a plurality of stops are spaced apart on the opposite side of the two first stops. The straight section is provided with two second stops near the first inclined section. The two second stops are respectively located on both sides of the straight section and perpendicular to the first stops. The second stops, the stops, and the protrusion form the positioning groove.

[0012] According to the first aspect embodiment of the present invention, the second stop portion is at a certain distance from the heat sink.

[0013] According to the MOS transistor single-tube fixing structure of the first aspect embodiment of the present invention, the straight section extends downward from the end away from the first inclined section to form the second connection portion.

[0014] According to the first aspect embodiment of the present invention, the first connecting part is a cylindrical structure, a pair of reinforcing strips are provided on the outer side of the cylindrical structure, and the PCB board is provided with a limiting hole for the cylindrical structure and the reinforcing strips to pass through, the limiting hole being clearance-fitted with the cylindrical structure.

[0015] According to the first aspect of the present invention, the MOS transistor single-tube fixing structure is wherein the first connecting part (340), the second connecting part, and the fixing member are integrally formed by polyoxymethylene injection molding.

[0016] According to the first aspect embodiment of the present invention, the single-tube fixing structure of the MOS transistor is provided with an elastic element inside the fixing member. The elastic element has a through hole for the fastener to pass through at the position opposite to the first connecting part. One end of the fastener presses against the elastic element, and the other end is threaded to the heat sink. The elastic element is made of carbon steel.

[0017] According to the MOS transistor single-tube fixing structure of the first aspect embodiment of the present invention, the fixing member is further provided with a third connecting part on the side facing the heat sink, the third connecting part is directly opposite the first connecting part, and the third connecting part is further provided with a guide hole for the fastener to pass through.

[0018] According to a second aspect of the present invention, a method for fixing a single MOS transistor is provided, employing the above-described single MOS transistor fixing structure, comprising the following steps:

[0019] S1. Insert the MOSFET into the positioning groove and make the MOSFET flush with the end of the second connection part;

[0020] S2. Snap the first connecting part onto the PCB board and press the fixing component continuously to make the fixing component fit seamlessly with the PCB board;

[0021] S3. After passing the fastener through the first connecting part and the fixing member in sequence, one end of the fastener presses against the fixing member, and the other end is threaded to the heat sink, so that the fixing member presses the MOSFET against the heat sink.

[0022] S4. Solder the pins of the fixed MOSFET to the PCB board.

[0023] The above-mentioned single-tube fixing method for MOSFETs has at least the following effects: compared with the existing technology, it reduces the use of fasteners while ensuring a stable connection, optimizes the clamping and installation methods, making installation simpler, eliminating the positioning and adjustment steps, effectively improving the installation efficiency of MOSFETs, extending the service life of the product, and facilitating subsequent disassembly and maintenance.

[0024] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0025] The present invention will be further described below with reference to the accompanying drawings and embodiments;

[0026] Figure 1 This is a structural schematic diagram of an embodiment of the present invention. Figure 1 ;

[0027] Figure 2 This is a schematic diagram of the structure of the fixing component in an embodiment of the present invention. Figure 1 ;

[0028] Figure 3 This is a schematic diagram of the structure of the fixing component in an embodiment of the present invention. Figure 2 ;

[0029] Figure 4 This is a schematic diagram of the structure of the fixing component in an embodiment of the present invention. Figure 3 ;

[0030] Figure 5 This is a structural schematic diagram of an embodiment of the present invention. Figure 2 . Detailed Implementation

[0031] This section will describe in detail specific embodiments of the present invention. Preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the drawings is to supplement the textual description with graphics, so that people can intuitively and vividly understand each technical feature and overall technical solution of the present invention, but they should not be construed as limiting the scope of protection of the present invention.

[0032] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and 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. Therefore, they should not be construed as limiting this invention.

[0033] In the description of this invention, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0034] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0035] Reference Figure 1 This invention provides a single-tube fixing structure for a MOSFET 200, comprising a PCB board 400, a fixing component 300, a MOSFET 200, and a heat sink 100 arranged sequentially.

[0036] The fixing component 300 includes a first connecting part 340, a second connecting part 330, and a deformable fixing member 310. The first connecting part 340 is disposed on the side of the fixing member 310 that is in contact with the PCB board 400, and the first connecting part 340 is snap-fitted to the PCB board 400. The second connecting part 330 is disposed at one end of the fixing member 310 facing the heat sink 100, and the other end of the fixing member 310 facing the heat sink 100 is also provided with a positioning groove 320. The first connecting part 340 is located between the second connecting part 330 and the positioning groove 320. The MOSFET 200 is snapped into the positioning groove 320 and in contact with the heat sink 100, and the pins 210 of the MOSFET 200 are fixedly connected to the PCB board 400.

[0037] In addition, the single-tube fixing structure of MOSFET 200 also includes a fastener 500. After the fastener 500 passes through the first connecting part 340 and the fixing member 310 in sequence, one end of the fastener 500 presses against the fixing member 310, and the other end is threaded to the heat sink 100. When the end of the fastener 500 is screwed into the heat sink 100, the middle part of the fixing member 310 deforms towards the heat sink 100 under the action of the fastener 500, so that the second connecting part 330 abuts against the heat sink 100, and the fixing member 310 presses the MOSFET 200 against the heat sink 100.

[0038] During assembly, the MOSFET 200 is pressed into the positioning groove 320 and adjusted to be flush with the second connecting part 330. After the first connecting part 340 is snapped into the PCB board 400, the fixing component 300 is pressed so that the fixing member 310 is in contact with the PCB board 400. At this time, the snapping of the first connecting part 340 into the PCB board 400 prevents the entire fixing component 300 from rotating. At the same time, due to the presence of the positioning groove 320, the MOSFET 200 is well positioned and fixed. When the fixing member 310 is in contact with the PCB board 400, as... Figure 5 As shown, at this time, the pin 210 of the MOSFET 200 is accurately positioned at the corresponding soldering position on the PCB board 400, which facilitates the subsequent batch soldering of the pin 210 of the MOSFET 200 onto the PCB board 400 without additional position adjustments. After completing the above operations, the fastener 500 is passed through the first connecting part 340 and the fixing member 310 in sequence. One end of the fastener 500 presses against the fixing member 310, and the other end is threaded to the heat sink 100. When the end of the fastener 500 is screwed into the heat sink 100, the middle part of the fixing member 310 is at the fastener 500. Under the action of the fastener 500, the MOSFET 200 deforms towards the heat sink 100, causing the second connecting part 330 to abut against the heat sink 100. The end of the fixing member 310 away from the second connecting part 330, under the force generated by the deformation, presses the MOSFET 200 against the heat sink 100. Regardless of the tightness of the fastener 500, it ensures complete contact between the MOSFET 200 and the heat sink 100, effectively improving heat dissipation efficiency. Simultaneously, because the fixing member 310 can undergo elastic deformation, even if the fastener 500 is excessively tightened, there will be no excessive clamping force that could damage the MOSFET 200. Compared to existing technologies, this method ensures a stable connection while reducing the use of fasteners 500, optimizing the clamping and installation methods, making installation simpler, eliminating the need for positioning and adjustment steps, effectively improving the installation efficiency of the MOSFET 200, extending the product's lifespan, and facilitating subsequent disassembly and maintenance.

[0039] It should be noted that the fastener in this embodiment is preferably a screw.

[0040] Furthermore, such as Figure 1 and Figure 2As shown, the fixing member 310 first extends horizontally to form a straight section, then extends downwards at an angle to form a first inclined section, and then extends upwards at an angle to form a second inclined section. The protruding end formed by the first and second inclined sections becomes the bottom of the positioning groove 320. It should be noted that the side of the protruding end that contacts the MOSFET is an arc surface. The straight section is attached to the PCB board 400. The first connecting part 340 is located on one side of the straight section, and the second connecting part 330 is located on the other side of the straight section. When the fastener 500 is screwed, the fastener 500 presses against the straight section, causing the straight section to move closer to the heat sink 100. Because the second connecting part 330 supports one end of the straight section, and the other end of the straight section is connected to the first inclined section, and the protruding end formed by the first and second inclined sections presses against the MOSFET, the second connecting part 330 abuts against the heat sink 100, because the protruding part 330... The contact area between the end and the MOSFET is smaller than the contact area between the second connection 330 and the heat sink 100. The static friction between the convex end and the MOSFET is smaller than the static friction between the MOSFET 200 and the heat sink 100. The static friction between the convex end and the MOSFET 200 is also smaller than the static friction between the second connection 330 and the heat sink 100. As the straight section continues to move downward, the angle between the first inclined section and the straight section continuously increases, that is, the fixing member 310 deforms, so that the convex end slides away from the second connection 330 while pressing against the MOSFET. Even if the installer over-tightens the fastener 500 without knowing how much to screw it in, the MOSFET 200 will not be damaged. The setting of the straight section and the first inclined section effectively converts the excessive force applied to the MOSFET 200 into elastic potential energy.

[0041] In other embodiments, such as Figure 2 and Figure 4As shown, first stop portions 360 extend from both sides of the first inclined section in a direction perpendicular to the straight section. Several baffles 362 are spaced apart on the opposite side of the two first stop portions 360. Two second stop portions 361 are positioned on the straight section near the first inclined section, located on opposite sides of the straight section and perpendicular to the first stop portions 360. The second stop portions 361, baffles 362, and protruding ends form a positioning groove 320. The two first stop portions 360 are arranged parallel to each other, and at least two baffles 362 are provided, with the distance between the two baffles 362 equal to or less than that of the MOS transistor 200. The width of the second stop 361 is used to intercept one end of the MOS transistor 200 in the length direction. The second stop 361 and the stop bar 362 form the groove wall of the positioning groove 320. When the MOS transistor 200 is placed in the positioning groove 320, one end of the MOS transistor 200 is first pressed against the second stop 361 to complete the initial positioning. Then, the MOS transistor 200 is slowly pressed into the positioning groove 320. The MOS transistor 200 is adjusted to be flush with the second connecting part 330 through the cooperation of the second stop 361 and the protruding end. Then, the positioned MOS transistor 200 is clamped and limited by the stop bar 362. It should be noted that the two second stops 361 are positioned near the first inclined section on the straight section. Even if the fixing member 310 is deformed by the subsequent screwing fastener 500, the straight section will not be horizontally moved towards the heat sink 100, so the second stops 361 will not push against the MOSFET 200. In other words, no matter how the fixing member 310 is deformed, the MOSFET 200 will not be displaced.

[0042] Furthermore, the second stop 361 is a certain distance away from the radiator 100, which allows for some adjustment space for the deformation of the fixing member 310.

[0043] In this embodiment, the end of the straight section away from the first inclined section extends downward to form the second connecting portion 330.

[0044] like Figure 2 and Figure 3 As shown, the first connecting part 340 is a cylindrical structure. A pair of reinforcing strips 342 are provided on the outer side of the cylindrical structure. The PCB board 400 is provided with limiting holes for the cylindrical structure and the reinforcing strips 342 to pass through. The limiting holes are clearance-fitted with the cylindrical structure, which facilitates the snap-fit ​​positioning of the fixing component 300 containing the MOSFET 200 onto the PCB board 400. While completing the positioning, it can also prevent the fixing component 300 from rotating, and also prevent the misalignment when soldering the pins 210 of the MOSFET 200 onto the PCB board 400. This improves the installation and soldering efficiency of the MOSFET 200, and allows the fixing component 300 containing the MOSFET 200 to be snap-fit ​​positioned onto the PCB board 400 in one go before soldering the pins 210 of the MOSFET 200.

[0045] In some embodiments, the first connecting portion 340, the second connecting portion 330, and the fixing member 310 are injection molded into a single structure using polyoxymethylene (POM). POM is a tough and elastic material that retains excellent creep resistance, geometric stability, and impact resistance even at low temperatures. Furthermore, POM possesses metal-like hardness, strength, and rigidity, exhibits excellent self-lubricating properties and fatigue resistance over a wide range of temperature and humidity, and is highly elastic, making it ideally suited for molding the fixing component 300 of this invention.

[0046] Furthermore, the fixed member 310 is provided with an elastic member 311 inside. The shape of the elastic member 311 is consistent with the bending shape of the fixed member 310 and extends from the straight section to the second inclined section. The elastic member 311 is provided with a through hole for the fastener 500 to pass through at the position opposite to the first connecting part 340. One end of the fastener 500 presses against the elastic member 311, and the other end is threaded to the radiator 100. The elastic member 311 is made of carbon steel and has elasticity. The elastic element 311 inside the fixing member 310 increases the stability of the fixing member 310 and the overall strength of the pressure block structure, which can also effectively extend the product's life. Compared with the fastener 500 acting directly on the fixing member 310, setting the elastic element 311 and making the locking force of the fastener 500 act on the elastic element 311 can avoid the fixing member 310 being crushed due to excessive tightening of the fastener 500. It can also extend the time for the fastener 500 to loosen and detach by slowly releasing the elastic potential energy when the fastener 500 loosens.

[0047] Preferably, the fixing member 310 is further provided with a third connecting part 350 on the side facing the radiator 100. The third connecting part 350 is directly opposite the first connecting part 340. The third connecting part 350 is also provided with a guide hole 341 for the fastener 500 to pass through. The threaded end of the fastener 500 is accurately guided into the threaded hole of the radiator 100 through the guide hole 341, which facilitates the subsequent tightening of the fastener 500. At the same time, the setting of the third connecting part 350 can also enhance the structural strength of the straight section. It should be noted that the third connecting part 350 is a certain distance away from the radiator 100, so that the fixing member 310 has a certain deformation space.

[0048] This invention also provides a method for fixing a MOS transistor 200 using the above-described single-transistor fixing structure, comprising the following steps:

[0049] S1. Insert the MOS transistor 200 into the positioning groove 320 and make the MOS transistor 200 flush with the end of the second connecting part 330;

[0050] S2. Snap the first connecting part 340 onto the PCB board 400 and press the fixing member 310 continuously to make the fixing member 310 fit seamlessly with the PCB board 400.

[0051] S3. After passing the fastener 500 through the first connecting part 340 and the fixing member 310 in sequence, one end of the fastener 500 presses against the fixing member 310, and the other end is threaded to the heat sink 100, so that the fixing member 310 presses the MOS tube 200 against the heat sink 100.

[0052] S4. Solder the pins 210 of the fixed MOSFET 200 to the PCB board 400.

[0053] During assembly, the MOSFET 200 is pressed into the positioning groove 320 and adjusted to be flush with the second connecting part 330. After the first connecting part 340 is snapped into the PCB board 400, the fixing component 300 is pressed so that the fixing member 310 is in contact with the PCB board 400. At this time, the snapping of the first connecting part 340 into the PCB board 400 prevents the entire fixing component 300 from rotating. At the same time, due to the presence of the positioning groove 320, the MOSFET 200 is well positioned and fixed. When the fixing member 310 is in contact with the PCB board 400, as... Figure 5 As shown, at this time, the pin 210 of the MOSFET 200 is accurately positioned at the corresponding soldering position on the PCB board 400, which facilitates the subsequent batch soldering of the pin 210 of the MOSFET 200 onto the PCB board 400 without additional position adjustments. After completing the above operations, the fastener 500 is passed through the first connecting part 340 and the fixing member 310 in sequence. One end of the fastener 500 presses against the fixing member 310, and the other end is threaded to the heat sink 100. When the end of the fastener 500 is screwed into the heat sink 100, the middle part of the fixing member 310 is at the fastener 500. Under the action of the fastener 500, the MOSFET 200 deforms towards the heat sink 100, causing the second connecting part 330 to abut against the heat sink 100. The end of the fixing member 310 away from the second connecting part 330, under the force generated by the deformation, presses the MOSFET 200 against the heat sink 100. Regardless of the tightness of the fastener 500, it ensures complete contact between the MOSFET 200 and the heat sink 100, effectively improving heat dissipation efficiency. Simultaneously, because the fixing member 310 can undergo elastic deformation, even if the fastener 500 is excessively tightened, there will be no excessive clamping force that could damage the MOSFET 200. Compared to existing technologies, this method ensures a stable connection while reducing the use of fasteners 500, optimizing the clamping and installation methods, making installation simpler, eliminating the need for positioning and adjustment steps, effectively improving the installation efficiency of the MOSFET 200, extending the product's lifespan, and facilitating subsequent disassembly and maintenance.

[0054] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A single-transistor fixed structure for a MOS transistor, characterized in that: It includes a PCB board (400), a fixing assembly (300), a MOSFET (200), and a heat sink (100) arranged sequentially, wherein The fixing component (300) includes a first connecting part (340), a second connecting part (330), and a fixing member (310) capable of deformation. The first connecting part (340) is disposed on the side of the fixing member (310) that is in contact with the PCB board (400), and the first connecting part (340) is snap-fitted to the PCB board (400). The second connecting part (330) is disposed at one end of the fixing member (310) facing the heat sink (100), and the other end of the fixing member (310) facing the heat sink (100) is also provided with a positioning groove (320). The first connecting part (340) is located between the second connecting part (330) and the positioning groove (320). The MOS transistor (200) is inserted into the positioning slot (320) and fits against the heat sink (100), and the pins (210) of the MOS transistor (200) are fixedly connected to the PCB board (400); It also includes a fastener (500), which passes through the first connecting part (340) and the fixing member (310) in sequence. One end of the fastener (500) presses against the fixing member (310), and the other end is threaded to the heat sink (100). When the end of the fastener (500) is screwed into the heat sink (100), the middle part of the fixing member (310) deforms towards the heat sink (100) under the action of the fastener (500), so that the second connecting part (330) abuts against the heat sink (100), and the fixing member (310) presses the MOS tube (200) against the heat sink (100). The fixing member (310) first extends horizontally to form a straight section, then extends downwards at an angle to form a first inclined section, and then extends upwards at an angle to form a second inclined section. The protruding end formed by the first inclined section and the second inclined section becomes the bottom of the positioning groove (320). The straight section is attached to the PCB board (400). The first connecting part (340) is disposed on one side of the straight section, and the second connecting part (330) is disposed on the other side of the straight section. First stops (360) extend from both sides of the first inclined section in a direction perpendicular to the straight section. Several baffles (362) are spaced apart on the opposite side of the two first stops (360). Two second stops (361) are provided on the straight section near the first inclined section. The two second stops (361) are located on both sides of the straight section and are perpendicular to the first stops (360). The second stops (361), the baffles (362), and the protrusion form the positioning groove (320). The second stops (361) are located on the straight section near the first inclined section. The straight section extends downward from the end away from the first inclined section to form the second connecting portion (330).

2. The MOS transistor single-tube fixed structure according to claim 1, characterized in that: The straight section extends downward from the end away from the first inclined section to form the second connecting portion (330).

3. The MOS transistor single-transistor fixed structure according to claim 1, characterized in that: The first connecting part (340) is a cylindrical structure. A pair of reinforcing strips (342) are provided on the outer side of the cylindrical structure. The PCB board (400) is provided with a limiting hole for the cylindrical structure and the reinforcing strips (342) to pass through. The limiting hole is clearance-fitted with the cylindrical structure.

4. The MOS transistor single-transistor fixed structure according to any one of claims 1 to 3, characterized in that: The first connecting part (340), the second connecting part (330), and the fixing member (310) are integrally molded from polyoxymethylene.

5. The MOS transistor single-transistor fixed structure according to claim 4, characterized in that: The fixing member (310) has an elastic element (311) inside. The elastic element (311) has a through hole for the fastener (500) to pass through at the position opposite to the first connecting part (340). One end of the fastener (500) presses against the elastic element (311), and the other end is threaded to the radiator (100). The elastic element (311) is made of carbon steel.

6. The MOS transistor single-transistor fixed structure according to claim 4, characterized in that: The fixing member (310) is further provided with a third connecting part (350) on the side facing the heat sink (100), the third connecting part (350) is directly opposite the first connecting part (340), and the third connecting part (350) is also provided with a guide hole (341) for the fastener (500) to pass through.

7. A method for fixing a single MOS transistor, characterized in that, The single-tube fixed structure of the MOS transistor according to any one of claims 1 to 6 includes the following steps: S1. Insert the MOS transistor (200) into the positioning groove (320) and make the MOS transistor (200) flush with the end of the second connection part (330); S2. Snap the first connecting part (340) onto the PCB board (400) and press the fixing member (310) continuously to make the fixing member (310) fit seamlessly with the PCB board (400); S3. After passing the fastener (500) through the first connecting part (340) and the fixing member (310) in sequence, one end of the fastener (500) presses against the fixing member (310), and the other end is threaded to the heat sink (100) so that the fixing member (310) presses the MOS tube (200) against the heat sink (100). S4. Solder the pins (210) of the fixed MOSFET (200) to the PCB board (400).

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