Welding jig for power module

Abstract

The utility model discloses a welding jig for a power module. The welding jig comprises a bottom plate and a pressure mechanism arranged on the bottom plate. The pressure mechanism comprises a base mounted on the bottom plate and further comprises a handle and a connecting rod, the handle is rotationally connected with a first rotating shaft arranged on the base, a second rotating shaft is arranged on the handle, and one end of the connecting rod is rotationally connected with the second rotating shaft; a sliding groove is formed in the connecting rod, a third rotating shaft is arranged on the base, and the third rotating shaft is matched with the sliding groove; and the other end of the connecting rod is used for applying pressure to a heat dissipation substrate of the power module. According to the utility model, pressure is applied to the heat dissipation substrate through the pressure mechanism, so that the deformation of the heat dissipation substrate can be ensured to be within a controllable range, the thickness of a welding layer of the power module is uniform, and the service life of the power module is prolonged; pressure is applied to the plastic package body through the pressing block mechanism, welding cavities can be reduced, and the heat conduction efficiency of a welding layer is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of power module manufacturing, in particular to a welding jig for a power module. Background Art

[0002] In the prior art, the soldering of power modules involves combining the heat dissipation substrate, solder, and plastic encapsulation in a self-superimposed and superimposed combination. During the cooling process of reflow soldering, the product is prone to bending due to the large difference in linear thermal expansion coefficients between the heat dissipation substrate and the plastic encapsulation. This also causes the soldering layer to have an uneven thickness, with a larger thickness in the center and a smaller thickness at the edges. This results in uneven heat conduction during product heat dissipation, reduced reliability, and warping of the appearance. Specifically, if the soldering layer thickness is uneven, thermal stress will be generated inside the module during use due to long-term high-power operation. Under special operating conditions, the module will also be subjected to large temperature changes, causing creep in weak areas of the soldering layer, leading to delamination, thereby reducing heat dissipation capacity and forming a vicious cycle that accelerates module failure. If the appearance warping is not within the control range, coolant will easily leak after installation, resulting in the risk of damage to the entire vehicle. Utility Model Content

[0003] Purpose of the utility model: The purpose of the utility model is to provide a welding jig for power modules, which can solve the problems of uneven thickness of the welding layer and severe deformation of the heat dissipation substrate in the prior art.

[0004] Technical solution: The welding jig for power modules described in the present invention includes a base plate and a pressure mechanism provided on the base plate;

[0005] The pressure mechanism includes a base mounted on the bottom plate, and also includes a handle and a connecting rod. The handle is rotatably connected to a first rotating shaft arranged on the base. The handle is provided with a second rotating shaft, and one end of the connecting rod is rotatably connected to the second rotating shaft; a slide groove is provided on the connecting rod, and a third rotating shaft is provided on the base, and the third rotating shaft cooperates with the slide groove; the other end of the connecting rod is used to apply pressure to the heat dissipation substrate of the power module.

[0006] Furthermore, the pressure mechanism also includes a roller. A fourth shaft is provided at the other end of the connecting rod. The roller is rotatably connected to the fourth shaft and is used to apply pressure to the heat sink substrate of the power module. The roller shifts the friction from sliding to rolling when pressing down on the heat sink substrate, effectively reducing friction and preventing scratches on the heat sink substrate.

[0007] Furthermore, there are four pressure mechanisms, which are located on the four sides of the heat dissipation substrate respectively. This can simultaneously apply pressure to the four sides of the heat dissipation substrate, so that the entire heat dissipation substrate is evenly stressed, thereby improving the effect of alleviating deformation of the heat dissipation substrate.

[0008] Furthermore, the device also includes a pressing mechanism, which includes a fixed plate and a pressing block. The fixed plate is mounted on the bottom plate and has a pin hole. The pressing mechanism also includes a pin, one end of which is fixedly connected to the pressing block, and the other end of which passes through the pin hole and applies pressure to the plastic package of the power module. This can apply pressure to the plastic package, thereby reducing the occurrence of weld voids and improving the thermal conductivity of the weld layer.

[0009] Furthermore, the pin is fitted into the pin hole with a clearance, so that the pressing block can be slightly restricted in position, but still have a certain space for free movement, which is convenient for fine-tuning the force application.

[0010] Furthermore, the pressing block is provided with a plurality of protrusions, which makes it easy to place some counterweights, thereby adjusting the force application.

[0011] Furthermore, the pressing block is provided with a plurality of recesses, which can facilitate the placement of some counterweights, thereby adjusting the force application.

[0012] Furthermore, a limiting frame is included to realize the mutual positioning of the plastic package of the power module and the heat dissipation substrate.

[0013] Beneficial effects: The utility model discloses a welding jig for a power module, which has the following beneficial effects compared with the prior art:

[0014] 1. Applying pressure to the heat dissipation substrate through the pressure mechanism can ensure that the deformation of the heat dissipation substrate is within a controllable range, making the thickness of the welding layer of the power module uniform, thereby increasing the life of the power module;

[0015] 2. Applying pressure to the plastic package body through the pressing mechanism can reduce the occurrence of welding voids and improve the thermal conductivity of the welding layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a structural diagram of a power module using a welding jig in a specific embodiment of the present invention;

[0017] Figure 2 for Figure 1 A front cross-sectional view of the transverse middle part of the

[0018] Figure 3 This is a three-dimensional diagram of the pressure mechanism in a specific embodiment of the present utility model;

[0019] Figure 4 This is a front view of the pressure mechanism in a specific embodiment of the present utility model;

[0020] Figure 5 This is a working state diagram of the connecting rod of the pressure mechanism moving to the horizontal position in a specific embodiment of the present utility model. DETAILED DESCRIPTION

[0021] This embodiment discloses a welding jig for power modules, such as Figure 1 As shown, it includes a base plate 1 and a pressure mechanism 5 arranged on the base plate 1. Figure 1 and Figure 2 The structure of the power module using the welding fixture is shown. The heat dissipation substrate 8 of the power module is arranged on the bottom plate 1, and solder 7 is provided between the heat dissipation substrate 8 and the plastic package 6. A limit frame 4 is also included to realize the mutual positioning of the plastic package 6 of the power module and the heat dissipation substrate 8, as shown in FIG. Figure 1 shown.

[0022] like Figure 2-4 As shown, the pressure mechanism 5 includes a base 53 mounted on the bottom plate 1, a handle 54 and a connecting rod 52. The handle 54 is rotatably connected to a first rotating shaft 541 provided on the base 53. The handle 54 is provided with a second rotating shaft 521. One end of the connecting rod 52 is rotatably connected to the second rotating shaft 521. A sliding groove 522 is provided on the connecting rod 52, and a third rotating shaft 523 is provided on the base 53. The third rotating shaft 523 cooperates with the sliding groove 522. The other end of the connecting rod 52 is used to apply pressure to the heat dissipation substrate 8 of the power module. In one embodiment, as Figure 2-4 As shown, the pressure mechanism 5 further includes a roller 51, and the other end of the connecting rod 52 is provided with a fourth shaft 511, the roller 51 is rotatably connected to the fourth shaft 511, and the roller 51 is used to apply pressure to the heat dissipation substrate 8 of the power module. Figure 1 As shown, the base 53 and the bottom plate 1 can be fixedly connected by pins and pin holes or other equivalent methods.

[0023] The working process of the pressure mechanism 5 is as follows:

[0024] The process of applying pressure: Push the handle 54 in the vertical direction to rotate the connecting rod 52 and press the roller 51 downward. Figure 2 and Figure 4 As shown, the roller 51 presses the heat dissipation substrate 8 to apply pressure thereto.

[0025] Release process: Press the handle 54 in the horizontal direction to rotate the connecting rod 52 and lift the roller 51. When the handle 54 is pressed to the horizontal position, Figure 5 As shown, the roller 51 is completely released and out of contact with the heat dissipation substrate 8.

[0026] In order to apply pressure to the four sides of the heat dissipation substrate 8 at the same time, so that the entire heat dissipation substrate 8 is evenly stressed and the deformation of the heat dissipation substrate 8 is alleviated, four pressure mechanisms 5 can be provided, which are respectively located on the four sides of the heat dissipation substrate 8, such as Figure 1 shown.

[0027] In order to apply pressure to the plastic package 6, thereby reducing the occurrence of welding voids and improving the thermal conductivity of the welding layer, the welding fixture in this embodiment also includes a pressing block mechanism 3. Figure 1 As shown, the pressing mechanism 3 includes a fixed plate 2 and a pressing block 9. The fixed plate 2 is fixed to the base plate 1 by a pin 22. The fixed plate 2 is provided with a pin hole 21. The pressing mechanism 3 also includes a pin 91. One end of the pin 91 is fixedly connected to the pressing block 9. The other end of the pin 91 passes through the pin hole 21 and applies pressure to the plastic package 6 of the power module. Figure 2 As shown. The pin 91 and the pin hole 21 can be loosely matched, so that the pressure block 9 can be slightly restricted in position, but still have a certain amount of space for free movement, which is convenient for fine-tuning the force application. In this specific embodiment, three pressure blocks 9 are used, which are arranged in parallel above the fixed plate 2, as shown in FIG. Figure 1 The pressing block 9 is provided with a number of protrusions 92 and depressions 93, which can facilitate the placement of some counterweights to adjust the force application.

[0028] The soldering jig in this embodiment applies pressure to the heat sink substrate 8 via the pressure mechanism 5, ensuring that the deformation of the heat sink substrate 8 is within a controllable range, making the solder layer thickness of the power module uniform, thereby improving the life of the power module. The pressure mechanism 3 applies pressure to the plastic package 6, reducing the occurrence of solder voids and improving the thermal conductivity of the solder layer.

[0029] The above is only a preferred specific implementation method of the present invention, but the protection scope of the present invention is not limited to this. Any changes or replacements that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed in the present invention should be covered by the protection scope of the present invention.

Claims

1. A welding jig for a power module, characterized by: It comprises a bottom plate (1) and a pressure mechanism (5) arranged on the bottom plate (1); The pressure mechanism (5) includes a base (53) mounted on the bottom plate (1), a handle (54) and a connecting rod (52), wherein the handle (54) is rotatably connected to a first rotating shaft (541) provided on the base (53), a second rotating shaft (521) is provided on the handle (54), and one end of the connecting rod (52) is rotatably connected to the second rotating shaft (521); a sliding groove (522) is provided on the connecting rod (52), and a third rotating shaft (523) is provided on the base (53), and the third rotating shaft (523) cooperates with the sliding groove (522); and the other end of the connecting rod (52) is used to apply pressure to the heat dissipation substrate (8) of the power module.

2. The welding jig for power module according to claim 1, characterized in that: The pressure mechanism (5) further comprises a roller (51), a fourth rotating shaft (511) is provided at the other end of the connecting rod (52), the roller (51) is rotatably connected to the fourth rotating shaft (511), and the roller (51) is used to apply pressure to the heat dissipation substrate (8) of the power module.

3. The welding jig for power module according to claim 1, characterized in that: There are four pressure mechanisms (5), which are respectively located on the four sides of the heat dissipation substrate (8).

4. The welding jig for power module according to claim 1, characterized in that: The device also includes a pressing block mechanism (3), which includes a fixed plate (2) and a pressing block (9). The fixed plate (2) is arranged on the bottom plate (1), and a pin hole (21) is provided on the fixed plate (2). The pressing block mechanism (3) also includes a pin (91), one end of the pin (91) is fixedly connected to the pressing block (9), and the other end of the pin (91) passes through the pin hole (21) and applies pressure to the plastic package (6) of the power module.

5. The welding jig for power module according to claim 4, characterized in that: The pin (91) is clearance-matched with the pin hole (21).

6. The welding jig for power module according to claim 4, characterized in that: The pressing block (9) is provided with a plurality of protrusions (92).

7. The welding jig for power module according to claim 4, characterized in that: The pressing block (9) is provided with a plurality of recesses (93).

8. The welding jig for power module according to claim 1, characterized in that: It also includes a limiting frame (4) for realizing the mutual positioning of the plastic package (6) of the power module and the heat dissipation substrate (8).

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