A secondary welding jig for a power module

Abstract

The application discloses a secondary welding jig of a power module and relates to the technical field of power module welding.The secondary welding jig comprises a bottom plate and a limiting assembly.A positioning tool is symmetrically arranged on the top of the bottom plate, and a soldering sheet positioning sheet is arranged in the positioning tool.A fixing assembly is connected to the four ends of the top of the bottom plate, a first pin positioning plate is arranged on the lower part of the outer side of the fixing assembly, a second pin positioning plate is arranged on the upper part of the outer side of the fixing assembly, and a through hole is formed in the inside of the first pin positioning plate and the second pin positioning plate.The positioning tool cooperates with the soldering sheet positioning sheet and the pin positioning plate to realize accurate alignment of the substrate, the DBC and the pin, the quick connection structure between the limiting assembly and the second pin positioning plate improves the efficiency of the pin transplanting, and then the sintering furnace is used for one-time forming welding, which significantly reduces the production steps and manual intervention, improves the power module assembly efficiency, and reduces the process complexity and manufacturing cost.

Description

Technical Field

[0001] This invention relates to the field of power module welding technology, specifically to a secondary welding fixture for power modules. Background Technology

[0002] A power module is an electronic component that integrates power semiconductor devices, drive circuits, protection circuits, and heat dissipation structures. It is used to efficiently realize power conversion and control. Its core function is to convert input power into stable voltage and current forms required by the load, while managing heat and ensuring system reliability.

[0003] Currently, for power modules in Economual and HP1 packages, secondary soldering refers to the soldering between the DBC and the substrate. For power modules in Easy 1B or 2B packages, secondary soldering refers to the soldering between the DBC and the pins. If the power module structure includes both the base plate and the pins, such as HPD or DC6i packages, it is generally necessary to first solder the DBC and the substrate, and then ultrasonically solder the pins to the DBC. This increases production costs and reduces production efficiency due to the increased number of processes. Summary of the Invention

[0004] The purpose of this invention is to provide a secondary welding fixture for power modules to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a secondary welding fixture for a power module, comprising a base plate and a limiting component. A positioning fixture is symmetrically arranged on the top of the base plate, and a welding sheet positioning piece is provided inside the positioning fixture. A fixing component is connected to the four ends of the top of the base plate, and a first pin positioning plate is sleeved on the lower outer side of the fixing component. A second pin positioning plate is sleeved on the upper outer side of the fixing component. Both the first and second pin positioning plates have through holes inside. The limiting component is located on the top of the second pin positioning plate and includes a guide hole. A guide hole is provided at the top outer end of the second pin positioning plate, and a threaded pin is slidably connected inside the guide hole. A support plate is threadedly connected to the upper outer side of the threaded pin, and a pin insertion plate is connected to the bottom of the support plate. A limiting hole is provided inside the pin insertion plate, and the diameter of the limiting hole is slightly smaller than the diameter of the through hole.

[0006] Furthermore, the fixing component includes a bolt, a washer is sleeved on the outer side of the middle part of the bolt, and a nut is threadedly connected to the outer side of the upper end of the bolt.

[0007] Furthermore, a clamping assembly is provided between the first pin positioning plate and the second pin positioning plate, and the clamping assembly includes a positioning groove. A positioning groove is provided on one side of both the first pin positioning plate and the second pin positioning plate, and a positioning block is slidably connected in the positioning groove. A screw is threadedly connected to the inside of the positioning block, and a stop post is rotatably connected to one end of the screw. A driving block is installed at one end of the stop post.

[0008] Furthermore, drive sleeves are fitted on both sides of the drive block, and transmission plates are provided at both ends of the drive sleeves. A clamping plate is connected to one side of the transmission plate, and a positioning hole is provided inside the clamping plate.

[0009] Furthermore, one end of the transmission plate is inclined, and the other end of the transmission plate is V-shaped.

[0010] Furthermore, the positioning hole is rectangular, and the position of the positioning hole corresponds one-to-one with the position of the through hole.

[0011] Furthermore, there are two clamping plates, and the two clamping plates are slidably connected to the first pin positioning plate and the second pin positioning plate, respectively.

[0012] Furthermore, one end of the first pin positioning plate and the second pin positioning plate is provided with a foolproof component, and the foolproof component includes a pressure plate. The pressure plates are symmetrically arranged at the top of one end of the first pin positioning plate and the second pin positioning plate, and a limit block is fixed at the bottom of one end of the pressure plate.

[0013] Furthermore, a sliding groove is provided on one side of the clamping plate, and a sliding strip is slidably connected inside the sliding groove, and the sliding strip is fixedly connected to the transmission plate.

[0014] Furthermore, a guide strip is slidably connected to the middle of one side of the clamping plate, and the guide strip is fixedly connected to the drive sleeve.

[0015] This invention provides a secondary welding fixture for power modules, which has the following advantages:

[0016] 1. This invention achieves precise alignment of the substrate, DBC, and pins by using positioning fixtures in conjunction with welding pads and pin positioning plates. At the same time, the quick-connect structure between the limiting component and the second pin positioning plate improves the efficiency of pin transfer. Then, the pins are formed and welded in one step in a sintering furnace, which significantly reduces production steps and manual intervention, improves the power module assembly efficiency, and reduces process complexity and manufacturing costs.

[0017] 2. When the screw is tightened, the clamping plate can be triggered to press the pins in a misaligned manner. The V-shaped side of the positioning hole guides the pins to automatically center, improving the insertion accuracy. The interlocking connection of the clamping assembly ensures convenient disassembly and assembly. This structure realizes vertical positioning of the pins and prevents them from falling off during transplantation, ensuring the accuracy of welding alignment. It is especially suitable for the high reliability fixing requirements of micro pins.

[0018] 3. During disassembly, loosening the nut will trigger the transmission plate to shift and relax, and the clamping plate will automatically release the pin, so that the pin positioning plate no longer clamps and positions the pin. This design eliminates pin damage caused by human error of forgetting to loosen the clamping components. At the same time, during disassembly, the guide bolt maintains the perpendicularity of the disassembly and assembly path, preventing the pin positioning plate from pushing the pin out of place. The built-in anti-misoperation mechanism improves product yield. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall three-dimensional structure of a secondary welding fixture for a power module according to the present invention;

[0020] Figure 2 This is a three-dimensional structural diagram of a positioning fixture for a secondary welding jig of a power module according to the present invention.

[0021] Figure 3 This is a schematic diagram of the first pin positioning plate of the secondary welding fixture for a power module of the present invention being flipped over and having pins placed in it.

[0022] Figure 4 This is a three-dimensional structural diagram of the limiting component of a secondary welding fixture for a power module according to the present invention.

[0023] Figure 5 This is a three-dimensional structural diagram of the first pin positioning plate of a secondary welding fixture for a power module according to the present invention.

[0024] Figure 6 This is a three-dimensional structural diagram of the clamping assembly of a secondary welding fixture for a power module according to the present invention.

[0025] Figure 7 This is a three-dimensional structural diagram of the limiting block of a secondary welding fixture for a power module according to the present invention.

[0026] Figure 8 This is a three-dimensional structural diagram of the error-proof component of a secondary welding fixture for a power module according to the present invention.

[0027] In the diagram: 1. Base plate; 2. Positioning fixture; 3. Welding sheet positioning piece; 4. Fixing assembly; 401. Bolt; 402. Washer ring; 403. Nut; 5. First pin positioning plate; 6. Second pin positioning plate; 7. Through hole; 8. Limiting assembly; 801. Guide hole; 802. Threaded pin; 803. Support plate; 804. Pin insertion plate; 805. Limiting hole; 9. Clamping assembly; 901. Positioning groove; 902. Positioning block; 903. Screw; 904. Stop post; 905. Drive block; 906. Drive sleeve; 907. Transmission plate; 908. Clamping plate; 909. Positioning hole; 10. Foolproof assembly; 1001. Pressure plate; 1002. Limiting block; 1003. Slide groove; 1004. Slide bar; 1005. Guide bar. Detailed Implementation

[0028] Please see Figures 1 to 4 The present invention provides a technical solution: a secondary welding fixture for a power module, comprising a base plate 1 and a limiting component 8. A positioning fixture 2 is symmetrically arranged on the top of the base plate 1, and a welding plate positioning piece 3 is provided inside the positioning fixture 2. A fixing component 4 is connected to the four ends of the top of the base plate 1, and a first pin positioning plate 5 is sleeved on the lower outer side of the fixing component 4. The fixing component 4 includes a bolt 401, a washer 402 is sleeved on the outer side of the middle part of the bolt 401, and a nut 403 is threadedly connected to the outer side of the upper end of the bolt 401. A second pin positioning plate 6 is sleeved on the outer side of the upper part of the fixing component 4, and the first pin... Both the positioning plate 5 and the second pin positioning plate 6 have through holes 7 inside. The limiting component 8 is located on the top of the second pin positioning plate 6 and includes a guide hole 801. The guide hole 801 is located at the outer top end of the second pin positioning plate 6. A threaded pin 802 is slidably connected inside the guide hole 801. A support plate 803 is threadedly connected to the outer upper end of the threaded pin 802. A pin insertion plate 804 is connected to the bottom of the support plate 803. A limiting hole 805 is located inside the pin insertion plate 804. The diameter of the limiting hole 805 is slightly smaller than the diameter of the through hole 7.

[0029] The specific operation is as follows: the positioning fixture 2 is used to position the substrate and the DBC. The pins are welded using a solder pad method, so the solder pad positioning piece 3 is used to quickly position the solder pad. When assembling the pins, the limiting component 8 can be flipped so that the support plate 803 is at the bottom. The limiting component 8 and the second pin positioning plate 6 are quickly connected through the guide hole 801 and the threaded pin 802, which makes it easy to insert the pin into the through hole 7. The limiting hole 805 on the pin insertion plate 804 will initially position the pin tip. After installation, the first pin positioning plate 5 is flipped and placed on the positioning fixture 2, so that all the pins can contact the solder pad, improving the convenience of insertion. After that, the fixing component 4 is fixed on the positioning fixture 2 with fasteners, and then the welding fixture is placed in the sintering furnace for sintering. This allows the substrate, DBC and pins to be welded at the same time, thereby reducing the number of processes, reducing production costs and improving production efficiency.

[0030] Please see Figures 5 to 6 A clamping assembly 9 is provided between the first pin positioning plate 5 and the second pin positioning plate 6. The clamping assembly 9 includes a positioning groove 901. A positioning groove 901 is provided on one side of both the first pin positioning plate 5 and the second pin positioning plate 6. A positioning block 902 is slidably connected in the positioning groove 901. A screw 903 is threadedly connected inside the positioning block 902. A stop post 904 is rotatably connected to one end of the screw 903. A driving block 905 is installed at one end of the stop post 904. Driving sleeves 905 are sleeved on both sides of the driving block 905. 06, and the two ends of the drive sleeve 906 are provided with transmission plates 907, one side of the transmission plate 907 is connected to a clamping plate 908, and the clamping plate 908 has a positioning hole 909 inside. One end of the transmission plate 907 is inclined, and the other end of the transmission plate 907 is V-shaped. The positioning hole 909 is rectangular, and the position of the positioning hole 909 corresponds one-to-one with the position of the through hole 7. There are two clamping plates 908, and the two clamping plates 908 are slidably connected to the first pin positioning plate 5 and the second pin positioning plate 6 respectively.

[0031] The specific operation is as follows: During the pin insertion process, because the diameter of the through hole 7 is slightly larger than the diameter of the pin, and the width of the positioning hole 909 is larger than the diameter of the through hole 7, the pin insertion is smoother. The diameter of the limiting hole 805 is slightly smaller than the diameter of the pin, and the pin tip is tapered. The limiting hole 805 provides limiting support for the bottom of the pin. Subsequently, because the positioning groove 901 limits the position of the positioning block 902, when the screw 903 is rotated, the clamping plate 908 moves via the stop post 904, drive block 905, drive sleeve 906, and transmission plate 907, causing the positioning hole 909 to engage with the through hole 7. When misalignment occurs between holes 7, clamping plate 908 will press the pin, fixing the pin in the first pin positioning plate 5 and the second pin positioning plate 6. This prevents the pin from falling off when the first pin positioning plate 5 is flipped and placed above the positioning fixture 2, thus improving the stability of the pin during transplantation. In addition, the V-shaped side of the positioning hole 909 will contact the outside of the pin, guiding it to be centered. At the same time, the pin is vertical when clamped, thus improving the accuracy of alignment. Furthermore, the positioning groove 901 and positioning block 902, and the drive block 905 and drive sleeve 906 are all interlocking, making disassembly and assembly very convenient.

[0032] Please see Figures 7 to 8 One end of the first pin positioning plate 5 and the second pin positioning plate 6 is provided with a foolproof component 10, and the foolproof component 10 includes a pressure plate 1001. The pressure plate 1001 is symmetrically provided at the top of one end of the first pin positioning plate 5 and the second pin positioning plate 6, and a limit block 1002 is fixed at the bottom of one end of the pressure plate 1001. A sliding groove 1003 is provided on one side of the clamping plate 908, and a sliding strip 1004 is slidably connected inside the sliding groove 1003. The sliding strip 1004 is fixedly connected to the transmission plate 907. A guide strip 1005 is slidably connected to the middle of one side of the clamping plate 908, and the guide strip 1005 is fixedly connected to the drive sleeve 906.

[0033] The specific operation is as follows: When the first pin positioning plate 5 and the second pin positioning plate 6 are connected and assembled using the fixing component 4, the washer 402 and the nut 403 will press and fix the pressure plate 1001, positioning the position of the limiting block 1002. The limiting block 1002 will then limit and guide one end of the transmission plate 907, causing the other end to clamp the drive sleeve 906. Therefore, when the drive sleeve 906 moves, it will control the clamping plate 908 to move synchronously, realizing the clamping function of the pin. After welding, when the first pin positioning plate 5 and the second pin positioning plate 6 need to be removed, after unscrewing the nut 403, the pressure plate 1001 will have a certain amount of room to move. At this time, under the guidance of the inclined surface of the limiting block 1002, it is impossible to apply stable pressure to the transmission plate 907 for guidance. The transmission plate 907 passes through the groove. 1003 and slide bar 1004 have a certain sliding space, so the transmission plate 907 and drive sleeve 906 will loosen, and the clamping plate 908 will not apply pressure to the pin, automatically releasing the clamping operation of the pin. This avoids the user forgetting to loosen the screw 903 during the process of lifting and disassembling the second pin positioning plate 6, which would cause the clamping plate 908 in the second pin positioning plate 6 to remain in the clamping state and damage the pin. Similarly, the transmission plate 907 in the first pin positioning plate 5 will also loosen the pin, avoiding damage to the welding part. This gives the welding fixture a certain degree of foolproof performance. Furthermore, during the upward movement of the first pin positioning plate 5 and the second pin positioning plate 6, the bolt 401 can guide them vertically to prevent them from tilting and pushing the pin out of place, further improving the product yield.

[0034] In summary, when using this secondary welding fixture for a power module, the first pin positioning plate 5 and the second pin positioning plate 6 are first connected and assembled using the fixing component 4. During this process, the washer 402 and the nut 403 will press and fix the pressure plate 1001 and position the limit block 1002. The limit block 1002 will then limit and guide one end of the transmission plate 907, so that the other end clamps the drive sleeve 906. Therefore, when the drive sleeve 906 moves, it will control the clamping plate 908 to move synchronously.

[0035] Secondly, the limiting component 8 is flipped so that the support plate 803 is at the bottom. The limiting component 8 and the second pin positioning plate 6 are quickly connected through the guide hole 801 and the threaded pin 802, which makes it easy to insert the pin into the through hole 7. During this process, since the diameter of the through hole 7 is slightly larger than the diameter of the pin, and the width of the positioning hole 909 is larger than the diameter of the through hole 7, the insertion of the pin is smoother. The diameter of the limiting hole 805 is slightly smaller than the diameter of the pin, and the end of the pin is tapered. The bottom of the pin can be limited and supported through the limiting hole 805.

[0036] Next, since the positioning groove 901 limits the position of the positioning block 902, when the screw 903 is rotated, the clamping plate 908 is moved through the stop post 904, the drive block 905, the drive sleeve 906, and the transmission plate 907, causing the positioning hole 909 to be misaligned with the through hole 7. The clamping plate 908 will then press the pin and fix the pin in the first pin positioning plate 5 and the second pin positioning plate 6, preventing the pin from falling off when the first pin positioning plate 5 is flipped and placed above the positioning fixture 2. This improves the stability of the pin during transplantation. Moreover, the V-shaped side of the positioning hole 909 will contact the outside of the pin, guiding it to be centered. At the same time, when clamped, the pin is vertical, improving the accuracy after alignment.

[0037] Then, the positioning fixture 2 is used to position the substrate and the DBC, and the solder pad position is quickly positioned by the solder pad positioning piece 3. After that, the second pin positioning plate 6 is lifted up to separate it from the limiting component 8, and the first pin positioning plate 5 is flipped and placed on the positioning fixture 2, so that all the pins can contact the solder pads, improving the convenience of insertion. After the fixing component 4 is fixed on the positioning fixture 2 with fasteners, the welding fixture is placed in the sintering furnace for sintering, so that the substrate, DBC and pins can be welded at the same time, thereby reducing the number of processes, reducing production costs and improving production efficiency.

[0038] Finally, after the welding has cooled, when it is necessary to remove the first pin positioning plate 5 and the second pin positioning plate 6, unscrew the nut 403. The pressure plate 1001 will then have some room to move. At this time, under the guidance of the inclined surface of the limiting block 1002, it cannot apply stable pressure to the transmission plate 907 for guidance. The transmission plate 907 has a certain sliding space through the slide groove 1003 and the slide bar 1004. Therefore, the transmission plate 907 and the drive sleeve 906 will become loose, and the clamping plate 908 will not apply pressure to the pin, automatically releasing the pin clamp. Tighten the operation to prevent the user from forgetting to loosen the screw 903 during the process of lifting and disassembling the second pin positioning plate 6, which would cause the clamping plate 908 inside the second pin positioning plate 6 to remain in a clamping state and damage the pin. Similarly, the transmission plate 907 inside the first pin positioning plate 5 will also loosen the pin to avoid damage to the welding part. In addition, during the upward movement of the first pin positioning plate 5 and the second pin positioning plate 6, the bolt 401 can guide them vertically to prevent them from tilting and pushing the pin out of place. Then remove the fixing component 4, loosen the positioning fixture 2, and remove the product.

[0039] It should be noted that, in this document, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0040] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only for the purpose of helping to understand the method and core ideas of the present invention. The above descriptions are only preferred embodiments of the present invention. It should be noted that due to the limitations of textual expression, while there are objectively infinite specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principles of the present invention, and can also combine the above technical features in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the inventive concept and technical solution to other situations without modification, should all be considered within the scope of protection of the present invention.

Claims

1. A secondary welding fixture for a power module, characterized in that, The device includes a base plate (1) and a limiting component (8). A positioning fixture (2) is symmetrically arranged on the top of the base plate (1), and a welding plate positioning piece (3) is provided inside the positioning fixture (2). A fixing component (4) is connected to the four ends of the top of the base plate (1). A first pin positioning plate (5) is sleeved on the lower outer side of the fixing component (4), and a second pin positioning plate (6) is sleeved on the upper outer side of the fixing component (4). Both the first pin positioning plate (5) and the second pin positioning plate (6) have through holes (7) inside. The limiting component (8) is located on the top of the second pin positioning plate (6). The limiting component (8) includes a guide hole (801), and the top outer end of the second pin positioning plate (6) is provided with a guide hole (801). A threaded pin (802) is slidably connected inside the guide hole (801). A support plate (803) is threadedly connected to the upper outer end of the threaded pin (802). A pin insertion plate (804) is connected to the bottom of the support plate (803). A limiting hole (805) is provided inside the pin insertion plate (804). The diameter of the limiting hole (805) is slightly smaller than the diameter of the through hole (7). The first pin positioning plate (5) and the second pin positioning plate (6) are connected to the guide hole (801). A clamping assembly (9) is provided between the pin positioning plates (6), and the clamping assembly (9) includes a positioning groove (901). The first pin positioning plate (5) and the second pin positioning plate (6) are each provided with a positioning groove (901) on one side, and a positioning block (902) is slidably connected in the positioning groove (901). A screw (903) is threadedly connected inside the positioning block (902), and a stop post (904) is rotatably connected to one end of the screw (903). A driving block (905) is placed at one end of the stop post (904), and driving sleeves (906) are sleeved on both sides of the driving block (905). The drive sleeve (906) has transmission plates (907) at both ends. A clamping plate (908) is connected to one side of the transmission plate (907). A positioning hole (909) is opened inside the clamping plate (908). A sliding groove (1003) is opened on one side of the clamping plate (908). A sliding strip (1004) is slidably connected inside the sliding groove (1003). The sliding strip (1004) is fixedly connected to the transmission plate (907). A guide strip (1005) is slidably connected to the middle of one side of the clamping plate (908). The guide strip (1005) is fixedly connected to the drive sleeve (906).

2. The secondary welding fixture for a power module according to claim 1, characterized in that, The fixing component (4) includes a bolt (401), a washer (402) is sleeved on the outer side of the middle part of the bolt (401), and a nut (403) is threaded on the outer side of the upper end of the bolt (401).

3. The secondary welding fixture for a power module according to claim 1, characterized in that, The upper part of one end of the transmission plate (907) is inclined, and the other end of the transmission plate (907) is V-shaped.

4. The secondary welding fixture for a power module according to claim 1, characterized in that, The positioning hole (909) is rectangular, and the position of the positioning hole (909) corresponds one-to-one with the position of the through hole (7).

5. The secondary welding fixture for a power module according to claim 1, characterized in that, The number of clamps (908) is set to two, and the two clamps (908) are slidably connected to the first pin positioning plate (5) and the second pin positioning plate (6) respectively.

6. The secondary welding fixture for a power module according to claim 1, characterized in that, One end of the first pin positioning plate (5) and the second pin positioning plate (6) is provided with a foolproof component (10), and the foolproof component (10) includes a pressure plate (1001). The pressure plate (1001) is symmetrically provided at the top of one end of the first pin positioning plate (5) and the second pin positioning plate (6), and a limit block (1002) is fixed at the bottom of one end of the pressure plate (1001).

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