Power tube fixing device

Abstract

The utility model discloses a power tube fixing device which comprises an upper cover, a lower cover and an elastic piece. The upper cover and the lower cover are connected in a matched manner, and the lower cover is suitable for being in contact with a power tube; and the elastic piece is arranged between the upper cover and the lower cover and applies elastic force to the lower cover, so that the power tube is elastically pressed by the lower cover. The power tube fixing device has the beneficial effects that compared with an existing power tube fixing device, the power tube fixing device has the advantages that the power tube is stably and effectively fixed through an innovative combined design; when the upper cover and the lower cover generate a thermal shrinkage phenomenon in a high-temperature environment, the pressure on the power tube is not reduced due to the elastic deformation of the elastic sheet; when the equipment is transported and runs for a long time, the torque attenuation of the screw is caused by vibration, and the elastic deformation of the elastic sheet can well offset the torque attenuation of the screw, so that enough pre-tightening force is ensured to compress the power tube.

Description

Technical Field

[0001] This application relates to the field of power transistor mounting, and more specifically to a power transistor mounting device. Background Technology

[0002] The primary function of a power transistor mounting device is to secure and protect the power transistor. Existing power transistor mounting devices are mainly one-on-one or one-on-two. A one-on-one mounting device consists of a mounting base, a positioning mounting hole, and a cantilever, with the cantilever having a boss that presses against the power transistor. A one-on-two mounting device is typically a flat plate with a central mounting hole and an opening or groove corresponding to the power transistor for positioning and initial securing. Current mounting methods primarily rely on the tightening force of screws to maintain the power transistor's position on the heatsink. Screws penetrate the positioning mounting hole in the mounting block to fix the power transistor to the ceramic substrate.

[0003] However, existing power transistor clamping blocks primarily use plastic and metal components. Plastic components are significantly affected by ambient temperature; when the temperature is too high, the plastic components shrink and deform, leading to a decrease in clamping force and loosening of the power transistor. Metal components are conductive in high-voltage environments, potentially causing short circuits, device burnout, or leakage. Furthermore, due to factors such as vibration and temperature changes during long-term operation, the tightening force of the screws gradually weakens, and the installation torque decreases, causing electronic components to loosen and affecting the performance and reliability of the equipment.

[0004] Meanwhile, existing power boards integrate various clamping blocks, such as one clamping two transistors and one clamping four transistors. Due to the different structures of these clamping blocks, the installation torque will differ if the force applied to each power transistor is to be the same, leading to torque misuse during installation. Existing power transistor clamping blocks lack protective structures. When the installation torque is too high, the excess clamping force will directly act on the power transistor and the insulating heat sink, potentially causing the insulating heat sink to crack and the power transistor to fail.

[0005] Therefore, improvements are needed to the existing power transistor mounting system. Utility Model Content

[0006] The purpose of this application is to provide a power transistor fixing device that can solve at least one of the defects in the above-mentioned background art.

[0007] To achieve at least one of the above objectives, the technical solution adopted in this application is as follows: a power transistor fixing device, comprising an upper cover, a lower cover, and an elastic element; the upper cover and the lower cover are connected in a mating manner, and the lower cover is adapted to contact the power transistor; the elastic element is installed between the upper cover and the lower cover and applies elastic force to the lower cover, thereby causing the lower cover to elastically press the power transistor.

[0008] Preferably, the power fixing device is mounted on the radiator; the elastic element is a spring, and the upper cover is fixedly mounted on the base plate of the radiator by fasteners, so that the upper cover compresses the spring to apply elastic force to the lower cover.

[0009] Preferably, the power tube fixing device is mounted on the heat sink; the elastic element is a spring sheet, which is connected to the base plate of the heat sink by fasteners, so that the spring sheet applies elastic force to the lower cover through deformation.

[0010] Preferably, the fastener is a bolt; the upper cover, the lower cover, and the spring sheet are respectively provided with coaxial mounting and positioning holes; the bolt passes through the mounting and positioning holes on the spring sheet and the lower cover in sequence to connect with the base plate of the heat sink; the size of the mounting and positioning hole corresponding to the upper cover is larger than the size of the bolt nut.

[0011] Preferably, the lower cover is provided with a pressing part that presses against the power tube, and the pressing part contacts the power tube through a provided boss.

[0012] Preferably, at least one of the pressing portions is provided on one side of the lower cover, and the plurality of pressing portions are spaced apart; a base is provided on the opposite side of the lower cover, and the lower cover abuts against the substrate of the heat sink through the base; the spring sheet includes a deformable portion, a connecting portion, and a supporting portion; the number and position of the deformable portions correspond to the pressing portions, the deformable portions and the supporting portions are respectively provided on opposite sides of the connecting portions, the supporting portions are limited to the lower cover, and the connecting portions are connected to the substrate of the heat sink through the fasteners, so that the deformable portions elastically abut against the corresponding pressing portions.

[0013] Preferably, the upper cover is provided with a positioning sleeve for mounting the PCB board, and the outer side of the positioning sleeve is provided with multiple positioning fins, which are arranged in an anti-reverse configuration.

[0014] Preferably, at least one extrusion part is provided on each of the opposite sides of the lower cover, and the multiple extrusion parts on one side are spaced apart; the spring sheet includes a deformation part and a connecting part; the deformation part is provided on the opposite sides of the connecting part, and the number and position of the deformation part on one side correspond to the extrusion part on the same side; the connecting part is connected to the substrate of the heat sink through the fastener, so that the deformation part elastically abuts against the corresponding extrusion part.

[0015] Preferably, a base is provided in the middle of the lower cover, and the base is adapted to abut against the substrate of the heat sink.

[0016] Preferably, a single power transistor has multiple pins; a separator is provided on the side of the upper cover, the separator being adapted to separate adjacent pins on the power transistor.

[0017] Compared with the prior art, the beneficial effects of this application are as follows:

[0018] Compared to existing power transistor fixing devices, this application uses an innovative combined design to stably and effectively fix the power transistor. When the upper and lower covers shrink due to high temperature, the elastic deformation of the spring ensures that the pressure on the power transistor does not decrease. During transportation and long-term operation, the torque of the screw decreases due to vibration. The elastic deformation of the spring can effectively offset the torque decrease of the screw, thereby ensuring sufficient preload to press the power transistor. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of Embodiment 1 of this utility model.

[0020] Figure 2 This is a flowchart illustrating the installation process of the upper cover, spring clip, and lower cover in Embodiment 1 of this utility model.

[0021] Figure 3 This is a schematic diagram of the structure of the upper cover in Embodiment 1 of this utility model.

[0022] Figure 4 This is a schematic diagram of the structure of the lower cover in Embodiment 1 of this utility model.

[0023] Figure 5 This is a cross-sectional structural diagram of Embodiment 1 of the present utility model.

[0024] Figure 6 This is a schematic diagram of the structure of the separator in Embodiment 1 of this utility model.

[0025] Figure 7 This is a schematic diagram of the overall structure of Embodiment 2 of this utility model.

[0026] Figure 8 This is a flowchart illustrating the installation process of the upper cover, spring clip, and lower cover in Embodiment 2 of this utility model.

[0027] Figure 9 This is a schematic diagram of the structure of the upper cover in Embodiment 2 of this utility model.

[0028] Figure 10 This is a schematic diagram of the lower cover in Embodiment 2 of this utility model.

[0029] Figure 11 This is a cross-sectional structural diagram of Embodiment 2 of the present invention.

[0030] Figure 12This is a cross-sectional structural diagram of Embodiment 3 of the present invention.

[0031] Figure 13 This is a schematic diagram of the mounting component in Embodiment 1 of this utility model.

[0032] Figure 14 This is a frontal view of the mounting components in the first embodiment of this invention.

[0033] In the diagram: 1. Upper cover, 10. Engaging groove, 11. First mounting positioning hole, 12. Separator, 2. Lower cover, 20. Extrusion part, 200. Limiting groove, 21. Second mounting positioning hole, 22. Protrusion, 23. Base, 24. Spring, 3. Connecting part, 30. Deformation part, 31. Support part, 32. Third mounting positioning hole, 33. Positioning sleeve, 40. Positioning fin, 5. Power tube, 50. Pin, 6. Insulating heat dissipation base, 7. Spring, 8. Mounting part, 80. Extension part, 9. PCB board. Detailed Implementation

[0034] The present application will be further described below with reference to specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0035] In the description of this application, it should be noted that the directional terms such as "center", "lateral", "longitudinal", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", and "counterclockwise" indicate the orientation and positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application 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. They should not be construed as limiting the specific protection scope of this application.

[0036] It should be noted that the terms "first," "second," etc., in the specification and claims of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0037] The terms “comprising” and “having”, and any variations thereof, in the specification and claims of this application are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or device.

[0038] One preferred embodiment of this application, such as Figure 1 , Figure 2and Figure 5 As shown, a power transistor fixing device is installed on a heat sink to press a power transistor 5 against the heat sink. The power transistor fixing device includes an upper cover 1, a lower cover 2, and an elastic element; the upper cover 1 and the lower cover 2 are fitted together, and the lower cover 2 can contact the power transistor 5. The elastic element is installed between the upper cover 1 and the lower cover 2 and applies a spring force to the lower cover 2, thereby causing the lower cover 2 to elastically press the power transistor 5 against the insulating heat dissipation substrate 6 of the heat sink.

[0039] It should be understood that after the elastic element is installed, it will come into contact with the lower cover 2, and there is a certain deformation space between the upper cover 1 and the lower cover 2. When the elastic element is subjected to external force, it will deform in the deformation space. Because the elastic element is in contact with the lower cover 2, it will apply elastic force to the lower cover 2 after deformation, so that the lower cover 2 will elastically press the power tube 5.

[0040] Therefore, the advantage of this solution compared to the traditional solution is that the elastic element can drive the lower cover 2 to elastically press the power tube 5; when the upper cover 1 and the lower cover 2 experience thermal shrinkage due to high temperature, the pressure on the power tube 5 will not decrease due to the elastic deformation of the elastic element; at the same time, because of the setting of the elastic element, when the equipment is transported, the torque of the fasteners is reduced due to vibration, and the elastic deformation of the elastic element can effectively offset the torque reduction of the fasteners, thereby ensuring that there is sufficient preload to press the power tube 5.

[0041] It should be understood that there are many ways to implement the upper cover 1, the lower cover 2, and the elastic element, and the specific structure of each method is different; for ease of understanding, three embodiments are described below.

[0042] Example 1:

[0043] In this embodiment, as Figure 2 and Figure 5 As shown, the elastic element is a spring sheet 3, which is connected to the substrate of the heat sink by fasteners so that the spring sheet 3 can apply elastic force to the lower cover 2 through deformation.

[0044] It is understandable that the fastener can be connected to the substrate of the heat sink. At the same time that the fastener and the substrate of the heat sink are connected, the spring 3 is also connected to the substrate of the heat sink through the fastener. At the same time that the fastener and the substrate of the heat sink are connected, the fastener will also exert force on the spring 3 to drive the spring 3 to deform. Then the spring 3 will apply elastic force to the lower cover 2 through deformation.

[0045] It should be understood that there are many types of fasteners that can achieve the above objectives, and bolts are preferred as fasteners in this embodiment.

[0046] In this embodiment, to facilitate the connection of bolts, mounting holes can be made on the lower cover 2 and the spring piece 3; alternatively, mounting holes can be made on the upper cover 1, the lower cover 2, and the spring piece 3. The specific structures are different in different ways. For ease of understanding, two examples are given below.

[0047] Example 1: such as Figure 2 As shown, a second mounting positioning hole 22 and a third mounting positioning hole 33 are respectively provided on the lower cover 2 and the spring piece 3; the bolt passes through the spring piece 3 and the third mounting positioning hole 33 and the second mounting positioning hole 22 of the lower cover 2 in sequence to connect with the base plate of the heat sink; after the connection is completed, the upper cover 1 is then connected to the lower cover 2.

[0048] Example 2: such as Figure 2 and Figure 3 As shown, the upper cover 1, lower cover 2, and spring plate 3 are respectively provided with a coaxial first mounting positioning hole 11, a second mounting positioning hole 22, and a third mounting positioning hole 33. The size of the first mounting positioning hole 11 on the upper cover 1 is larger than the size of the bolt nut. The bolt extends into the upper cover 1 through the first mounting positioning hole 11 and then passes through the spring plate 3 and the third mounting positioning hole 33 and the second mounting positioning hole 22 on the lower cover 2 in sequence to connect with the base plate of the heat sink.

[0049] It is understandable that the size of the bolt nut is larger than the size of the bolt. When the bottom end of the bolt is connected to the nut and contacts the surface of the spring 3, if the bolt continues to be connected to the base plate of the heat sink, the bolt nut will squeeze the spring 3, thereby causing the spring 3 to deform and thus causing the spring 3 to apply elastic force to the lower cover 2.

[0050] It is also understandable that when the bolt is connected to a certain extent, the bolt nut can abut against the spring piece 3 and drive the spring piece 3 to deform; that is, the remaining surface area of ​​the bottom end of the nut after removing the screw is exerting a force on the spring piece 3. Therefore, the dimensional relationship between the third mounting positioning hole 33 and the second mounting positioning hole 22 is also particularly important. There are multiple ways to set the dimensional relationship between the third mounting positioning hole 33 and the second mounting positioning hole 22. For ease of understanding, two specific examples will be used to explain in detail below.

[0051] Example 1: The size of the third mounting positioning hole 33 on the spring 3 is equal to the size of the second mounting positioning hole 22 on the lower cover 2.

[0052] Example 2: The size of the third mounting positioning hole 33 on the spring 3 is smaller than the size of the second mounting positioning hole 22 on the lower cover 2.

[0053] It should be understood that if the size of the third mounting positioning hole 33 is the same as the size of the second mounting positioning hole 22, and the thickness of the spring piece 3 is relatively thin, then when the nut applies force to the spring piece 3, the lower cover 2 serves as support below the point where the force is applied. Even if the spring piece 3 is squeezed for a long time, the spring piece 3 will not be dented around the third mounting positioning hole 33.

[0054] However, if the size of the third mounting positioning hole 33 is smaller than the size of the second mounting positioning hole 22, when the nut applies force to the spring piece 3, the area below the spring piece 3 where the force is applied will be suspended without the lower cover 2 for support. Over time, the spring piece 3 will develop a depression around the third mounting positioning hole 33. However, this does not affect the requirements of this application; it simply means that when the size of the third mounting positioning hole 33 is the same as the size of the second mounting positioning hole 22, the compression of the spring piece 3 by the nut is more stable. Therefore, in this embodiment, Example 1 is preferred; those skilled in the art can choose according to actual needs.

[0055] In this embodiment, as Figure 2 and Figure 5 As shown, the lower cover 2 is provided with a pressing part 20 that is pressed together with the power tube 5. The pressing part 20 contacts the power tube 5 through a provided boss 200.

[0056] It is understandable that the extrusion part 20 may not have the boss 200, allowing the extrusion part 20 to directly press against the power tube 5. However, under the same pressing force, if the extrusion part 20 has the boss 200, the contact area between the extrusion part 20 and the power tube 5 can be reduced. By reducing the contact area, the pressure can be increased, so that the extrusion part 20 can increase the pressure through the boss 200 to improve the pressing effect of the lower cover 2 on the power tube 5.

[0057] In this embodiment, as Figure 2 As shown, at least one extrusion part 20 is provided on one side of the lower cover 2. If multiple extrusion parts 20 are provided, they are spaced apart on the same side of the lower cover 2. The spring piece 3 includes a deformation part 31, a connecting part 30, and a supporting part 32. The number and position of the deformation parts 31 correspond to the extrusion parts 20. The deformation parts 31 and the supporting parts 32 are respectively provided on opposite sides of the connecting part 30. The supporting part 32 is in a limiting fit with the lower cover 2. The connecting part 30 is connected to the base plate of the heat sink by bolts, so that the deformation parts 31 elastically abut against the corresponding extrusion parts 20.

[0058] It is understood that the number of extrusion parts 20 should correspond to the number of power tubes 5 that need to be compressed. The deformation part 31 is used to deform and extrude the extrusion parts 20, and its installation position and number should also correspond to the position and number of extrusion parts 20 provided on the lower cover 2. The third mounting positioning hole 33 provided on the spring piece 3 is located on the connecting part 30, and the nut of the bolt extrudes the connecting part 30. As for the support part 32, the support part 32 and the connecting part 30 are arranged in a perpendicular relationship. The lower cover 2 is provided with a limiting groove 21, and the support part 32 can extend into the limiting groove 21 to perform a limiting engagement with the limiting groove 21, so that the spring piece 3 can be limited to the lower cover 2 through the support part 32. The specific number of extrusion parts 20 can be selected by those skilled in the art according to actual needs. In this embodiment, such as Figure 2 As shown, the number of extrusion parts 20 is preferably two, and correspondingly, the number of deformation parts 31 is also two, thereby forming a power tube fixing device with one extrusion and two deformations.

[0059] In this embodiment, as Figure 5 As shown, after the bolt is connected to the substrate of the heat sink to a certain extent, the bolt nut will apply pressure to the connection part 30, and the spring piece 3 will deform as a whole after being subjected to the pressure applied by the nut, so that multiple deformed parts 31 will press the corresponding extrusion part 20, thereby causing the extrusion part 20 to elastically press the power tube 5 through the boss 200.

[0060] In this embodiment, the spring 3 is deformed by applying downward pressure to it through the nut, thereby applying force to the compression part 20. However, the preload applied by the nut to the spring 3 may not reach the required preload, and may be slightly less or more. For slightly less preload, simply continue to connect the bolt to the heat sink substrate. However, for preload applied by the nut to the spring 3 that is more than the required preload, the lever arm needs to be adjusted to avoid damaging the power transistor 5 and the insulating heat sink substrate 6.

[0061] Therefore, in this embodiment, as Figure 2 , Figure 4 and Figure 5 As shown, the lower cover 2 has a base 24 on the side opposite to where the pressing part 20 is provided, and the base 24 abuts against the base plate of the heat sink; at the same time, the size of the lever arm is adjusted by controlling the position of the third mounting positioning hole 33.

[0062] It is understandable that the base 24 is in direct contact with the substrate of the heat sink, and the extrusion part 20 is in direct contact with the power tube 5 through the boss 200. The base 24 and the extrusion part 20 can form a lever by being connected by bolts. The position of the third mounting positioning hole 33 determines whether this lever is a force-saving lever or a force-consuming lever. That is, if the opening position of the third mounting positioning hole 33 is moved towards the base 24, the base 24 will be able to withstand more preload. Therefore, the extrusion force of the extrusion part 20 on the power tube 5 can be controlled by adjusting the opening position of the third mounting positioning hole 33 according to the preload requirement of the power tube 5.

[0063] In this embodiment, as Figure 2 As shown, the upper cover 1 is provided with a positioning sleeve 4 for installing the PCB board 9. Multiple positioning fins 40 are provided on the outer side of the positioning sleeve 4, and the multiple positioning fins 40 are arranged to prevent reverse rotation.

[0064] It is understandable that there are various ways to determine the number and specific arrangement of the positioning fins 40, including but not limited to the two described below.

[0065] Method 1: There are two positioning fins 40; the angle between the two positioning fins 40 along the circumference of the positioning sleeve 4 is not equal to 180°.

[0066] Method 2: For example Figure 2 As shown, there are three positioning fins 40; the three positioning fins 40 are distributed at intervals along the circumference of the positioning sleeve 4; at the same time, along the clockwise direction of the circumference of the positioning sleeve 4, the angle between the first positioning fin 40 and the third positioning fin 40 is less than or equal to 180°, and the second positioning fin 40 is located at any point between the first positioning fin 40 and the third positioning fin 40.

[0067] It should be understood that both of the above methods can meet the needs of this application, and those skilled in the art can choose according to actual needs; in this embodiment, the second method is preferred.

[0068] In this embodiment, as Figure 1 As shown, a single power transistor 5 has multiple pins 50. During assembly and transportation, the power transistor 5 will vibrate. If adjacent pins 50 on the power transistor 5 come into contact during the vibration, the power transistor 5 will burn out.

[0069] Therefore, in this embodiment, as Figure 6 As shown, a separator 12 is provided on the side of the upper cover 1. The separator 12 can separate adjacent pins 50 on the power transistor 5 so that even if the power transistor 5 is vibrated during assembly and transportation, the adjacent pins 50 on the power transistor 5 will not come into contact, which saves a lot of trouble for the assembly and transportation of the power transistor 5.

[0070] In this embodiment, to reduce installation errors and prevent the power transistor 5 from shifting during soldering, thus ensuring the power transistor 5 maintains the correct height tolerance with the mounting device and causing stress on the PCB board 9 and displacement of the power transistor 5, this embodiment... Figure 13 and Figure 14 As shown, the power tube fixing device is also provided with a mounting part 8; the mounting part 8 is block-shaped; extension parts 80 are provided at both ends of the mounting part 8 along the length direction perpendicular to the mounting part 8.

[0071] The specific installation method is as follows: When installing the power transistor 5, first place the power transistor 5 on the boss 200, and then use the mounting part 8 to fix the power transistor fixing device with the power transistor 5 to the PCB board 9; use fasteners to fix the power transistor fixing device to the mounting part 8, and the PCB board 9 and the extension part 80 are connected by multiple fasteners. The pins 50 of the power transistor 5 extend out of the PCB board 9 for soldering. After soldering is completed, remove the multiple fasteners, remove the mounting part 8, and fix the PCB board 9 with the power transistor 5 onto the heat sink with the insulating heat sink 6, thus completing the assembly.

[0072] In this embodiment, there are several ways to connect the upper cover 1 and the lower cover 2. The upper cover 1 can be fixedly mounted on the substrate of the heat sink, with the lower cover 2 and the upper cover 1 engaging in a limiting fit. Alternatively, the upper cover 1 can be not connected to the substrate of the heat sink, but only connected to the lower cover 2. In this embodiment, the latter method is preferred for connecting the upper cover 1 and the lower cover 2. For ease of understanding, the specific fitting structure will be described in detail below.

[0073] Specifically, such as Figure 3 and Figure 4 As shown, the upper cover 1 is provided with multiple engaging grooves 10, and the lower cover 2 is provided with multiple protrusions 23; the protrusions 23 can engage with the engaging grooves 10 to make the upper cover 1 and the lower cover 2 engage with each other.

[0074] Example 2:

[0075] Compared to Example 1, Example 2 differs in that: Figure 7 , Figure 8 and Figure 11 As shown, at least one extrusion part 20 is provided on each of the opposite sides of the lower cover 2, and the multiple extrusion parts 20 on one side are spaced apart. The spring sheet 3 includes a deformable part 31 and a connecting part 30. The deformable parts 31 are provided on opposite sides of the connecting parts 30, and the number and position of the deformable parts 31 on one side correspond to the extrusion parts 20 on the same side. The connecting part 30 is connected to the substrate of the heat sink by fasteners so that the deformable parts 31 elastically abut against the corresponding extrusion parts 20.

[0076] It is understood that the pressing parts 20 are respectively provided at intervals on each of the opposite sides of the lower cover 2, and the number of pressing parts 20 should correspond to the number of power tubes 5 that need to be pressed. The deformation part 31 is used to deform to press the pressing parts 20, and its installation position and number should also correspond to the position and number of the pressing parts 20 provided on the lower cover 2; the third mounting positioning hole 33 provided on the spring piece 3 is located on the connecting part 30, and the nut of the bolt is used to press the connecting part 30. As for the specific number of pressing parts 20, those skilled in the art can choose according to actual needs; in this embodiment, such as Figure 8 As shown, the number of extrusion parts 20 is preferably four, and correspondingly, the number of deformation parts 31 is also four, thereby forming a power tube fixing device with one extrusion and four deformation parts.

[0077] In this embodiment, the specific method for setting the base 24 and adjusting the excess preload of the extrusion section 20 on the power tube 5 is as follows.

[0078] like Figure 8 and Figure 10 As shown, the lower cover 2 has a base 24 in the middle of the side closest to the heat sink substrate, and the base 24 can abut against the heat sink substrate. Specifically, when the preload applied by the extrusion section 20 to the power tube 5 does not exceed the upper limit of the preload that can be withstood, there is a gap between the base 24 and the heat sink substrate; when the preload applied by the extrusion section 20 to the power tube 5 exceeds the upper limit that can be withstood, the base 24 will contact the heat sink substrate; at this time, no matter how large the preload applied by the extrusion section 20 to the power tube 5 is, the part exceeding the upper limit will be conducted to the heat sink substrate.

[0079] It should be understood that the differences between this embodiment and Embodiment 1 are as described above; the rest of the settings and structures are the same as in Embodiment 1.

[0080] Example 3:

[0081] Compared to Embodiment 1 and Embodiment 2, Embodiment 3 differs in that: Figure 12 As shown, the elastic element is spring 7, and the upper cover 1 is fixedly installed on the base plate of the radiator by fasteners so that the upper cover 1 compresses the spring 7 to apply elastic force to the lower cover 2.

[0082] It should be understood that if the upper cover 1 is fixedly installed on the substrate of the heat sink by fasteners, then when the lower cover 2 and the upper cover 1 are installed together, the upper cover 1 will definitely squeeze the spring 7. Since the upper cover 1 is fixedly installed, the spring 7 will apply elastic force to the lower cover 2 so that the lower cover 2 can elastically press the power tube 5.

[0083] It should also be noted that the number and installation position of the springs 7 correspond to the number and position of the compression parts 20.

[0084] The basic principles, main features, and advantages of this application have been described above. Those skilled in the art should understand that this application is not limited to the above embodiments. The embodiments and descriptions in the specification are merely the principles of this application. Various changes and modifications can be made to this application without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection claimed by this application is defined by the appended claims and their equivalents.

Claims

1. A power transistor fixing device, characterized in that, It includes an upper cover, a lower cover, and an elastic element; the upper cover and the lower cover are connected in a mating manner, and the lower cover is adapted to contact the power transistor; the elastic element is installed between the upper cover and the lower cover and applies elastic force to the lower cover, thereby causing the lower cover to elastically press the power transistor.

2. The power transistor fixing device as described in claim 1, characterized in that, The power tube fixing device is installed on the heat sink; the elastic element is a spring, and the upper cover is fixedly installed on the base plate of the heat sink by fasteners, so that the upper cover compresses the spring to apply elastic force to the lower cover.

3. The power transistor fixing device as described in claim 1, characterized in that, The power tube fixing device is installed on the heat sink; the elastic element is a spring sheet, which is connected to the base plate of the heat sink by fasteners so that the spring sheet applies elastic force to the lower cover through deformation.

4. The power transistor fixing device as described in claim 3, characterized in that, The fastener is a bolt; the upper cover, the lower cover, and the spring are respectively provided with coaxial mounting and positioning holes; the bolt passes through the mounting and positioning holes on the spring and the lower cover in sequence to connect with the base plate of the heat sink; the size of the mounting and positioning hole corresponding to the upper cover is larger than the size of the bolt nut.

5. The power transistor fixing device as described in claim 4, characterized in that, The lower cover is provided with a pressing part that presses against the power tube, and the pressing part contacts the power tube through a provided boss.

6. The power transistor fixing device as described in claim 5, characterized in that, At least one of the pressing portions is provided on one side of the lower cover, and the pressing portions are spaced apart. A base is provided on the opposite side of the lower cover, and the lower cover abuts against the substrate of the heat sink through the base. The spring sheet includes a deformable portion, a connecting portion, and a supporting portion. The number and position of the deformable portions correspond to the pressing portions. The deformable portions and the supporting portions are respectively provided on opposite sides of the connecting portions. The supporting portions are limited to the lower cover. The connecting portions are connected to the substrate of the heat sink through the fasteners, so that the deformable portions elastically abut against the corresponding pressing portions.

7. The power transistor fixing device as described in claim 6, characterized in that, The upper cover is provided with a positioning sleeve for installing the PCB board. Multiple positioning fins are provided on the outer side of the positioning sleeve, and the multiple positioning fins are arranged to prevent reverse rotation.

8. The power transistor fixing device as described in claim 5, characterized in that, At least one extrusion part is provided on each of the opposite sides of the lower cover, and the multiple extrusion parts on one side are spaced apart; the spring sheet includes a deformation part and a connecting part; the deformation part is provided on the opposite sides of the connecting part, and the number and position of the deformation part on one side correspond to the extrusion part on the same side; the connecting part is connected to the substrate of the heat sink through the fastener, so that the deformation part elastically abuts against the corresponding extrusion part.

9. A power transistor fixing device as described in claim 8, characterized in that, A base is provided in the middle of the lower cover, and the base is adapted to abut against the substrate of the heat sink.

10. A power transistor fixing device as described in any one of claims 1-9, characterized in that, The power transistor has multiple pins; the side of the top cover has a separator adapted to separate adjacent pins on the power transistor.

Images