Welding jig for power module system

Abstract

The invention discloses a welding jig for a power module system. The welding jig comprises a pressing block, a hanging column, a DCB signal pin positioning plate and a heat dissipation bottom plate positioning plate. A pressing block positioning hole is formed in the pressing block, and the pressing block positioning hole is used for a signal pin and is used for ensuring that the pin seat does not drift in the welding process; the hanging column is formed on the lower surface of the pressing block and used for assembling the pressing block to the DCB signal pin positioning plate. The DCB signal pin positioning plate is provided with a DCB positioning column which is used for ensuring that the DCB does not drift in the welding process; the heat dissipation bottom plate positioning plate is provided with a positioning column and a positioning block, and the positioning column penetrates through the third positioning hole of the DCB signal pin positioning plate and the heat dissipation bottom plate positioning hole; the positioning blocks are used for ensuring that the Z direction of the assembled heat dissipation bottom plate does not deviate, and the positioning columns are used for ensuring that the heat dissipation bottom plate does not deviate in the XY plane.

Description

Technical Field

[0001] This invention relates to the field of semiconductors, and in particular to a welding fixture for power module systems. Background Technology

[0002] The booming development of the electric vehicle industry has promoted the rapid development of the electric vehicle component field. As a key component of the three-electric system, IGBT power modules have also developed rapidly. The packaging and output power of power modules have made great progress. In terms of improving power density, in addition to further improving the chip, packaging innovation is also an important improvement measure. Among them, the innovation of heat dissipation base plate has made a major contribution to the improvement of output power.

[0003] The power module soldering process is a critical production step in the power module manufacturing process, where the Substrate subassemblies are soldered to the heat sink base plate. After the system soldering is completed, the Substrate subassemblies are connected and fixed to the base plate. The solder layer void ratio and signal pin position accuracy are important indicators for evaluating the quality of the system soldering. The fixtures used for system soldering are an important guarantee for the stability and reliability of the system soldering and play a crucial role in the soldering process.

[0004] The existing technical solution first restricts the position of the heat sink base plate by using a fixture, then adds a limiting mechanism in the fixture to restrict the position of the solder pads and the substrate, and finally achieves the requirements of void ratio and signal pin position accuracy after welding by limiting the relative positions of the substrate, solder pads and heat sink base plate before system welding.

[0005] Existing technologies achieve the requirements for void ratio and signal pin position accuracy after welding by ensuring the relative positions of the Substrate, solder pad, and heat sink before welding. However, due to the different thermal expansion coefficients of the Substrate, solder pad, and heat sink, warping deformation inevitably occurs during the welding process. After warping deformation, the position of the signal pin shifts and the thickness consistency of the solder layer under the Substrate deteriorates, leading to increased difficulty in controlling the void ratio.

[0006] Warping deformation has a significant impact on the weld void rate and signal pin position accuracy, and has the most significant impact on the most widely used three-phase full-bridge module. Summary of the Invention

[0007] The summary of this invention introduces a series of simplified concepts, all of which are simplifications of existing technologies in the field, and will be further explained in detail in the detailed description section. This summary is not intended to limit the key features and essential technical features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.

[0008] The technical problem to be solved by the present invention is to provide a power module system welding fixture that can accurately position the substrate, solder pads and heat sink base plate.

[0009] To solve the above-mentioned technical problems, the present invention provides a power module system welding fixture, including: a pressure block 41, a hanging post 42, a DCB signal pin positioning plate 43, and a heat dissipation base plate positioning plate 44; The pressure block 41 has a pressure block positioning hole 411, which provides a signal needle 31 to ensure that the needle seat 32 does not drift during the welding process. Hanging post 42 is formed on the lower surface of pressure block 41 and is used to assemble pressure block 41 to DCB signal needle positioning plate 43. DCB signal pin positioning plate 43, which is provided with DCB positioning post 433, is used to ensure that DCB33 does not drift during the welding process; The heat dissipation base plate positioning plate 44 is provided with positioning post 441 and positioning block 442. Positioning post 441 passes through the third positioning hole 434 of DCB signal pin positioning plate 43 and the heat dissipation base plate positioning hole 11. The positioning block 442 is used to ensure that the heat dissipation base plate 1 does not shift in the Z direction after assembly, and each positioning post 441 is used to ensure that the heat dissipation base plate 1 does not shift in the XY plane.

[0010] Preferably, the power module system welding fixture is further improved by including: a connecting positioning block 45, which is inserted into the fourth positioning hole 443 on the heat sink base plate positioning plate 44, and is used to connect the positioning DCB signal pin positioning plate 43 and the heat sink base plate positioning plate 44.

[0011] Preferably, the welding fixture for the power module system is further improved, with a trapezoidal chamfer formed on the edge of the positioning hole 411 of the pressure block.

[0012] Preferably, in a further improved power module system welding fixture, the DCB signal pin positioning plate 43 is further provided with a first positioning hole 431 and a second positioning hole 432. The first positioning hole 431 and the second positioning hole 432 have different dimensions.

[0013] Preferably, the welding fixture for the power module system is further improved, and the positions of the first positioning hole 431 and the second positioning hole 432 are used to compensate for the warping deformation of the base plate after the system is welded.

[0014] Preferably, the welding fixture for the power module system is further improved, and the material of the welding fixture for the power module system is aluminum alloy.

[0015] This invention can achieve at least the following technical effects; 1. By using the positioning method of this invention, the Substrate, solder pad, and heat sink base plate can all be limited by the same positioning post, resulting in a smaller cumulative positional tolerance and helping to improve the positional accuracy of the signal pin.

[0016] 2. Substrate signal needle position accuracy can be achieved quickly: The pressure block of this invention presses down on the needle seat, and the positioning plate restricts the offset of the signal needle. The pressure block and the positioning plate work together to achieve the correct position.

[0017] 3. The first and second positioning holes of the present invention take into account warping deformation and have undergone position compensation, enabling more accurate positioning. 4. This invention reduces the void ratio by applying pressure to the Substrate through a pressing block. Attached Figure Description

[0018] The accompanying drawings are intended to illustrate the general characteristics of the methods, structures, and / or materials used in specific exemplary embodiments of the invention, supplementing the description in the specification. However, the drawings are schematic diagrams not drawn to scale and may not accurately reflect the precise structural or performance characteristics of any of the given embodiments. The drawings should not be construed as limiting or restricting the range of numerical values ​​or properties covered by exemplary embodiments of the invention. The invention will now be described in further detail with reference to the accompanying drawings and specific embodiments: Figure 1 This is a schematic diagram of the Substrate assembly.

[0019] Figure 2 This is a schematic diagram of the structure of an embodiment of the present invention. Figure 1 .

[0020] Figure 3 This is a schematic diagram of the structure of an embodiment of the present invention. Figure 2 .

[0021] Figure 4 This is a schematic diagram of the structure of an embodiment of the present invention. Figure 3 .

[0022] Figure 5 This is a schematic diagram of the structure of an embodiment of the present invention. Figure 4 .

[0023] Figure 6 This is a schematic diagram of the structure of an embodiment of the present invention. Figure 5 .

[0024] Explanation of reference numerals in the attached figures 1 is the heat dissipation base plate 2 is a solder pad 3 is the Substrate subassembly. 4 is the welding fixture for the power module system of the present invention. 31 is the signal pin. 32 is the needle hub 33 is DCB 41 is a pressing block 42 is a hanging column 43 is the DCB signal pin positioning plate. 44 is the heat dissipation base plate positioning plate. 411 is the positioning hole for the pressure block. 431 is the first positioning hole 432 is the second positioning hole. 433 is the DCB positioning post. 434 is the third positioning hole. 441 is a positioning post. 442 is a positioning block 443 is the fourth positioning hole. Detailed Implementation

[0025] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can fully understand other advantages and technical effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through different specific embodiments, and various details in this specification can also be applied based on different viewpoints, with various modifications or changes made without departing from the overall design concept of the invention. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. The following exemplary embodiments of the present invention can be implemented in many different forms and should not be construed as being limited to the specific embodiments set forth herein. It should be understood that these embodiments are provided to make the disclosure of the present invention thorough and complete, and to fully convey the technical solutions of these exemplary embodiments to those skilled in the art. It should be understood that when an element is referred to as "connected" or "combined" to another element, the element can be directly connected or combined to the other element, or there may be intermediate elements. The difference is that when an element is referred to as "directly connected" or "directly combined" to another element, there are no intermediate elements. Throughout the drawings, the same reference numerals always denote the same elements.

[0026] First embodiment; refer to Figures 2 to 6 As shown, the present invention provides a power module system welding fixture for welding and fixing a heat sink base plate 1, a welding sheet and a Substrate subassembly 3, comprising: a pressure block 41, a hanging post 42, a DCB signal pin positioning plate 43 and a heat sink base plate positioning plate 44. The pressure block 41 has a pressure block positioning hole 411, which provides a signal needle 31 to ensure that the needle seat 32 does not drift during the welding process. Hanging post 42 is formed on the lower surface of pressure block 41 and is used to assemble pressure block 41 to DCB signal needle positioning plate 43. DCB signal pin positioning plate 43, which is provided with DCB positioning post 433, is used to ensure that DCB33 does not drift during the welding process; The heat dissipation base plate positioning plate 44 is provided with positioning post 441 and positioning block 442. Positioning post 441 passes through the third positioning hole 434 of DCB signal pin positioning plate 43 and the heat dissipation base plate positioning hole 11. The positioning block 442 is used to ensure that the heat dissipation base plate 1 does not shift in the Z direction after assembly, and each positioning post 441 is used to ensure that the heat dissipation base plate 1 does not shift in the XY plane.

[0027] Furthermore, it should be understood that although the terms "first," "second," etc., may be used herein to describe different elements, components, regions, layers, and / or portions, these elements, components, regions, layers, and / or portions should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer, or portion from another element, component, region, layer, or portion. Therefore, without departing from the teachings of exemplary embodiments according to the present invention, the first element, component, region, layer, or portion discussed below may also be referred to as the second element, component, region, layer, or portion.

[0028] Second embodiment; Continue to refer to Figures 2 to 6 As shown, the present invention provides a power module system welding fixture for welding and fixing a heat sink base plate 1, a welding sheet and a Substrate subassembly 3, comprising: a pressure block 41, a hanging post 42, a DCB signal pin positioning plate 43 and a heat sink base plate positioning plate 44. The pressure block 41 has a pressure block positioning hole 411, which provides a signal needle 31 to ensure that the needle seat 32 does not drift during the welding process. Hanging post 42 is formed on the lower surface of pressure block 41 and is used to assemble pressure block 41 to DCB signal needle positioning plate 43. DCB signal pin positioning plate 43, which is provided with DCB positioning post 433, is used to ensure that DCB33 does not drift during the welding process; The heat dissipation base plate positioning plate 44 is provided with positioning post 441 and positioning block 442. Positioning post 441 passes through the third positioning hole 434 of DCB signal pin positioning plate 43 and the heat dissipation base plate positioning hole 11. The positioning block 442 is used to ensure that the heat dissipation base plate 1 does not shift in the Z direction after assembly, and each positioning post 441 is used to ensure that the heat dissipation base plate 1 does not shift in the XY plane. The connecting positioning block 45 is inserted into the fourth positioning hole 443 on the heat sink base plate positioning plate 44, and is used to connect the positioning DCB signal pin positioning plate 43 and the heat sink base plate positioning plate 44.

[0029] Optionally, the edge of the positioning hole 411 of the pressure block in the first or second embodiment may be further improved by forming a trapezoidal chamfer.

[0030] Optionally, the first or second embodiment can be further improved by forming a first positioning hole 431 and a second positioning hole 432 on the DCB signal needle positioning plate 43. The first positioning hole 431 and the second positioning hole 432 have different dimensions; The positions of the first positioning hole 431 and the second positioning hole 432 are used to compensate for the warping deformation of the base plate after welding, based on the position reference system.

[0031] Alternatively, the first or second embodiment can be further improved by using aluminum alloy as the material for the welding fixture of the power module system.

[0032] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It will also be understood that, unless explicitly defined herein, terms such as those defined in a general dictionary shall be interpreted as having the meaning consistent with their meaning in the relevant field context, and not as having an idealized or overly formal meaning.

[0033] The present invention has been described in detail above through specific embodiments and examples, but these are not intended to limit the invention. Many modifications and improvements can be made by those skilled in the art without departing from the principles of the invention, and these should also be considered within the scope of protection of the present invention.

Claims

1. A power module system welding fixture, characterized by, Comprise: Briquetting (41), hanging column (42), DCB signal needle positioning plate (43) and heat dissipation bottom plate positioning plate (44); Briquetting (41) is formed with briquetting positioning hole (411), and the briquetting positioning hole (411) is used for signal needle (31), which is used to ensure that the needle seat (32) does not drift during welding process; Hanging column (42) is formed in the lower surface of briquetting (41), which is used to assemble briquetting (41) to DCB signal needle positioning plate (43); DCB signal needle positioning plate (43) is provided with DCB positioning column (433), which is used to ensure that DCB (33) does not drift during welding process; Heat dissipation bottom plate positioning plate (44) is provided with positioning column (441) and positioning block (442), positioning column (441) passes through the third positioning hole (434) of DCB signal needle positioning plate (43) and heat dissipation bottom plate positioning hole (11); Positioning block (442) is used to ensure that the Z direction of the assembled heat dissipation bottom plate (1) does not deviate, and each positioning column (441) is used to ensure that the heat dissipation bottom plate (1) does not deviate in XY plane.

2. The power module system welding fixture of claim 1, wherein, Also include: Connecting positioning block (45) is inserted into the fourth positioning hole (443) on the heat dissipation bottom plate positioning plate (44), which is used to connect and position DCB signal needle positioning plate (43) and heat dissipation bottom plate positioning plate (44).

3. The power module system welding fixture of claim 1, wherein: The edge of briquetting positioning hole (411) is formed with trapezoidal chamfer.

4. The power module system welding fixture of claim 1, wherein: DCB signal needle positioning plate (43) is also formed with first positioning hole (431) and second positioning hole (432); The size of first positioning hole (431) and second positioning hole (432) is different.

5. The power module system welding fixture of claim 4, wherein: The first positioning hole (431) and the second positioning hole (432) are used for position compensation of the amount of bottom plate warping deformation after position reference system welding.

6. The power module system welding fixture of claim 1, wherein: The material of power module system welding fixture is aluminum alloy.

Images