Smt fixture for power module

Abstract

This utility model discloses an SMT fixture for power supply modules, comprising a fixture body consisting of a pressure plate, a tray, a locking mechanism, and a spring module. The spring module is disposed below the pressure plate and includes a pressure rod and a pressure block disposed at the bottom of the pressure rod. A spring is sleeved on the pressure rod, and the top of the pressure rod is embedded in the pressure plate. The bottom of the pressure block contacts the top of the SIP module. The pressure block, through the downward pressure of the pressure plate and the cooperation of the pressure rod and the spring, presses the SIP module tightly. The tray is disposed at the bottom of the SIP module, and the locking mechanism is disposed between the pressure plate and the tray. The locking mechanism locks the spring module, thus resetting and limiting its movement. This utility model solves the problems of solder joint failure, misalignment, and difficulty in soldering the pins due to deformation during SMT soldering of power supply modules in the prior art.

Description

Technical Field

[0001] This utility model relates to the field of fixture structures, and in particular to an SMT fixture for power modules. Background Technology

[0002] In the prior art, when processing power module devices (SIP), due to the large-area ENIG (chemical nickel immersion gold) treatment on the surface, the surface tension of the molten solder varies greatly at different parts of the module during reflow soldering, which causes device misalignment. Especially during SMT soldering, frequent open solder joints and misalignment abnormalities occur. In addition, because the side functional pins are half-moon hole pads, the module is deformed by heat during soldering, causing the bottom of some pins to rise, which makes it difficult to apply solder.

[0003] In view of this, this technical solution proposes an SMT fixture for power modules, which uses a combination of pressure plate, spring module and locking mechanism to achieve continuous clamping of power modules, prevent displacement caused by uneven force on components during soldering, and at the same time make the device in close contact with the PCB, improve the soldering effect of the pins, and further improve product quality. Utility Model Content

[0004] The present invention aims to at least partially solve one of the technical problems in the related art. Therefore, the main objective of this invention is to provide an SMT fixture for power modules, which aims to solve the problems of solder joint failure, misalignment, and difficulty in soldering the pins due to deformation during the SMT soldering process of power modules in the prior art.

[0005] To achieve the above objectives, this utility model provides an SMT fixture for power supply modules, comprising a fixture body consisting of a pressure plate, a tray, a locking mechanism, and a spring module.

[0006] The spring module is disposed below the pressure plate. The spring module includes a pressure rod and a pressure block disposed at the bottom of the pressure rod. A spring is sleeved on the pressure rod. The top of the pressure rod is embedded in the pressure plate. The bottom of the pressure block contacts the top of the SIP module. The pressure block, through the downward pressure of the pressure plate and the cooperation of the pressure rod and the spring, presses the SIP module tightly.

[0007] The tray is located at the bottom of the SIP module, and the locking mechanism is located between the pressure plate and the tray. The pressure plate and the tray are locked together by the locking mechanism to reset and limit the spring module.

[0008] As a further embodiment of this utility model, both the pressure plate and the tray are rectangular structures, and the locking mechanism is distributed at each corner of the pressure plate and the tray.

[0009] As a further improvement of this utility model, the locking mechanism is a rotary buckle structure.

[0010] As a further embodiment of this utility model, both the pressure plate and the tray are integrally formed metal plate structures.

[0011] As a further improvement of this utility model, the tray is provided with a positioning groove, and the pressure plate achieves accurate positioning and assembly through the cooperation of the positioning post and the positioning groove.

[0012] As a further embodiment of this utility model, the spring modules are arranged on opposite sides of the pressure plate, and the number of spring modules arranged in a single row is at least 4.

[0013] The beneficial effects of this utility model are as follows:

[0014] This technical solution addresses issues such as solder joint failure, misalignment, and difficulty in soldering leads due to differences in molten solder surface tension and thermal deformation during SMT soldering of existing power module modules. Through structural optimization, it significantly improves soldering quality. In traditional processes, modules are prone to deformation after heating, and uneven soldering occurs due to poor contact of the half-moon hole pad leads. This solution employs a design combining a pressure plate and tray with spring modules. The spring modules apply continuous and uniform downward pressure to the module via pressure blocks at the bottom of the pressure rod, ensuring a tight fit between the module and the PCB and counteracting thermal expansion deformation. Rotary snap-locking mechanisms at the four corners quickly lock the pressure plate and tray, ensuring stable compression of the spring modules and preventing interference from external soldering forces. The pressure plate and tray utilize a one-piece rectangular metal structure, with precise alignment of positioning slots and positioning posts, enhancing overall rigidity and avoiding assembly deviations. The spring modules are symmetrically arranged on both sides of the pressure plate, with at least four groups per row, forming multi-point balanced pressure and further reducing localized stress concentration. The above improvements ensure that the module is subjected to uniform force and has a fixed position during the welding process, effectively solving problems such as offset, deformation and pin lifting, improving the pin tinning effect and welding yield, while simplifying the assembly process and adapting to the needs of high-efficiency production. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the technical solutions of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram showing the front view (including perspective) of the clamp body and the setting of the pressure plate and locking mechanism in this utility model.

[0017] Figure 2 This is a side view of the clamp body and a schematic diagram showing the spring module, locking mechanism and positioning components of the present invention.

[0018] Figure 3 This is a partially enlarged schematic diagram of the spring module pressing the SIP module in this utility model.

[0019] [Explanation of Markings on Main Components / Assemblies]

[0020] label name label name 1 Fixture body 122 Press block 10 pressure plate 13 tray 11 Locking mechanism 130 Positioning Post 12 Spring Module 131 positioning groove 120 Compression bar 2 SIP module 121 spring Detailed Implementation

[0021] as follows:

[0022] Please see the appendix Figure 1-3 ,

[0023] The main structure includes a clamp body 1 consisting of a pressure plate 10, a tray 13, a locking mechanism 11, and a spring module 12. The spring module 12 is located below the pressure plate 10 and includes a pressure rod 120 and a pressure block 122 located at the bottom of the pressure rod 120. A spring 121 is sleeved on the pressure rod 120. The top of the pressure rod 120 is embedded in the pressure plate 10. The bottom of the pressure block 122 contacts the top of the SIP module 2. The pressure block 122 presses the SIP module 2 tightly through the downward pressure of the pressure plate 10 and the cooperation of the pressure rod 120 and the spring 121. The tray 13 is located at the bottom of the SIP module 2. The locking mechanism 11 is located between the pressure plate 10 and the tray 13. The pressure plate 10 and the tray 13 are locked by the locking mechanism 11 to reset and limit the spring module 12.

[0024] The working principle is as follows:

[0025] This technical solution significantly improves the stability and soldering quality of power modules in SMT soldering by optimizing the fixture structure design. In traditional processes, due to the chemical nickel immersion gold treatment on the surface of the power module, there are significant differences in the surface tension of the molten solder during reflow soldering. In addition, the module is prone to deformation after heating, leading to component misalignment, solder joint failure, and lifting of the pin bottom of the side crescent-shaped pads, causing difficulties in soldering. To address these issues, this solution designs a fixture structure consisting of a pressure plate 10, a tray 13, a spring module 12, and a locking mechanism 11. The spring module 12 is located below the pressure plate 10, and the pressure block 122 at the bottom of its pressure rod 120 directly contacts the top of the module. The elastic deformation of the spring 121 provides continuous and uniform downward pressure, ensuring a tight fit between the module and the PCB, effectively counteracting displacement caused by thermal expansion or solder tension during soldering. Locking mechanisms 11 are distributed at the four corners of the pressure plate 10 and the tray 13, employing a rotating snap-fit ​​structure for quick locking and releasing. After the pressure plate 10 is pressed down, it secures the spring modules 12 in a compressed state, preventing loosening caused by pressure rebound. The bottom of the tray 13 has a positioning groove 131 that cooperates with the positioning post 130 of the pressure plate 10 to achieve precise alignment, ensuring balanced force on the modules. The spring modules 12 are arranged on opposite sides of the pressure plate 10, with at least four groups per row, further improving the uniformity of pressure distribution. Through this structure, this solution solves the problems of misalignment, deformation, and poor pin contact caused by insufficient or uneven pressure in traditional welding, significantly improving welding yield and product reliability.

[0026] The assembly and disassembly process of this scheme's structure can be as follows:

[0027] During assembly, first place the tray 13 on the workbench, ensuring its positioning groove 131 aligns with the bottom of the SIP module 2. Then, place the SIP module 2 on the tray 13, ensuring its bottom is flush against the tray 13. Next, align the pressure plate 10 with the positioning groove 131 of the tray 13 via the positioning pin 130 and press it down, causing the pressure block 122 at the bottom of the pressure plate 10 to contact the top of the SIP module 2. At this time, the pressure rod 120 of the spring module 12 contracts under pressure, the spring 121 enters a compressed state, and the pressure block 122 applies uniform downward pressure to the module. After the pressure plate 10 is fully pressed down, rotate the rotating snap-lock mechanism 11 at the four corners of the pressure plate 10 and the tray 13 to lock and fix them, ensuring that the spring module 12 remains compressed, thereby continuously pressing the module. Finally, check whether the components are accurately aligned and whether the pressure distribution is uniform.

[0028] During disassembly, first release the rotating latches of the four corner locking mechanisms 11 between the pressure plate 10 and the tray 13, releasing the compressed state of the spring module 12. The spring 121 rebounds, and the pressure plate 10 automatically rises and disengages from the SIP module 2. Then, separate the pressure plate 10 from the tray 13 and remove the welded SIP module 2. If it is necessary to disassemble the spring module 12, the pressure rod 120 and spring 121 assembly can be further removed from the pressure plate 10 to complete the disassembly of the fixture. Throughout the process, care must be taken to avoid excessive external force impact on the spring module 12 or the locking mechanism 11 to ensure the reusability of the fixture.

[0029] Reference Appendix Figure 1 , 2 In a preferred embodiment of this utility model, both the pressure plate 10 and the tray 13 are rectangular structures, and the locking mechanism 11 is distributed at each corner of the pressure plate 10 and the tray 13.

[0030] In this technical solution, the pressure plate 10 and the tray 13 adopt a rectangular design, and locking mechanisms 11 are set at the four corners. This allows the pressure to be evenly distributed on the module surface, avoiding deformation or displacement caused by uneven local force. The four corner locking also enhances the overall structural rigidity, prevents loosening caused by thermal expansion during welding, and facilitates quick alignment and fixation, improving operational efficiency.

[0031] Reference Appendix Figure 1 , 2 In a preferred embodiment of this utility model, the locking mechanism 11 is a rotating buckle structure.

[0032] The rotary buckle structure of this technical solution can quickly lock or release the pressure plate 10 and the tray 13 by manual rotation, which is simple and time-saving to operate. At the same time, the mechanical interlocking characteristics of the buckle ensure a stable pressing state and avoid accidental loosening caused by external force or thermal deformation during the welding process.

[0033] Reference Appendix Figure 1 In a preferred embodiment of this utility model, both the pressure plate 10 and the tray 13 are integrally formed metal plate structures.

[0034] The pressure plate 10 and the tray 13 adopt an integral metal structure, which has high overall strength and is not easily deformed, ensuring stable pressure bearing during welding. The seamless design reduces the risk of loosening, and the improved processing precision makes the pressing more uniform, simplifying the manufacturing process and enhancing durability.

[0035] Reference Appendix Figure 2 In a preferred embodiment of this utility model, a positioning groove 131 is provided on the tray 13, and the pressure plate 10 achieves accurate positioning and assembly through the cooperation of the positioning post 130 and the positioning groove 131.

[0036] The positioning groove 131 on the tray 13 and the positioning post 130 on the pressure plate 10 can be quickly aligned during assembly through mechanical cooperation, ensuring that the pressure plate 10 is pressed down accurately, avoiding uneven pressure caused by manual adjustment deviation, simplifying operation steps, reducing assembly time, making the pressure block 122 contact the module more tightly, and improving welding stability and consistency.

[0037] Reference Appendix Figure 1 , 2 In a preferred embodiment of this utility model, the spring modules 12 are arranged on opposite sides of the pressure plate 10, and the number of spring modules 12 arranged in a single row is at least 4.

[0038] This technical solution symmetrically distributes the spring modules 12 on both sides of the pressure plate 10, with at least 4 sets in a single row, so that the downward pressure evenly covers the surface of the module, avoiding excessive or insufficient local pressure. The multi-point symmetrical pressure can not only offset the thermal deformation stress during welding, but also ensure that the module and PCB are tightly attached, reducing the risk of displacement.

[0039] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made based on the present utility model's technical concept and the contents of the present utility model's technical solution specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. An SMT fixture for power supply modules, characterized in that, include The main body of the clamp consists of a pressure plate, a tray, a locking mechanism, and a spring module. The spring module is disposed below the pressure plate. The spring module includes a pressure rod and a pressure block disposed at the bottom of the pressure rod. A spring is sleeved on the pressure rod. The top of the pressure rod is embedded in the pressure plate. The bottom of the pressure block contacts the top of the SIP module. The pressure block, through the downward pressure of the pressure plate and the cooperation of the pressure rod and the spring, presses the SIP module tightly. The tray is located at the bottom of the SIP module, and the locking mechanism is located between the pressure plate and the tray. The pressure plate and the tray are locked together by the locking mechanism to reset and limit the spring module.

2. The SMT fixture for power modules according to claim 1, characterized in that, Both the pressure plate and the tray are rectangular structures, and the locking mechanism is located at each corner of the pressure plate and the tray.

3. The SMT fixture for power modules according to claim 1, characterized in that, The locking mechanism is a rotary latch structure.

4. The SMT fixture for power modules according to claim 1, characterized in that, Both the pressure plate and the tray are integrally formed metal plate structures.

5. The SMT fixture for power supply modules according to claim 1, characterized in that, The tray has a positioning groove, and the pressure plate achieves accurate positioning and assembly through the cooperation of the positioning pin and the positioning groove.

6. The SMT fixture for power modules according to claim 1, characterized in that, The spring modules are arranged on opposite sides of the pressure plate, and the number of spring modules arranged in a single row is at least 4.

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