Clamp for welding

Abstract

The utility model discloses a welding clamp which is characterized by comprising a fixing frame, a chip frame, a pressing block frame, a pressing block and a fastening assembly. The two ends of the chip frame are clamped on the fixing frame, the pressing block frame is located on the side, away from the fixing frame, of the chip frame, the fastening assembly sequentially penetrates through the pressing block frame, the chip frame and the fixing frame, the chip frame is provided with a chip hole corresponding to a chip, the pressing block frame is provided with a pressing block hole corresponding to the chip hole, and the pressing block is inserted into the chip hole and the pressing block hole. According to the welding clamp, the chip and the to-be-welded plate are more tightly contacted during welding, more importantly, a tin sheet and the chip do not move to generate offset, so that the problem of abnormal welding caused by offset in the prior art is avoided, the voidage under the chip and on a single-tube frame can be reduced, the welding time is effectively shortened, and the welding efficiency is improved. And the welding yield and the welding efficiency are improved, operation is convenient, and the structure is simple.

Description

TECHNICAL FIELD

[0001] The utility model relates to diffusion welding technical field, concretely relates to a clamp for welding. BACKGROUND

[0002] Instant liquid phase diffusion connection usually adopts the material of lower melting point than the base material as the intermediate layer, when heated to the connection temperature, the intermediate layer melts, forms the instant liquid film on the bonding surface, in the heat preservation process, with the diffusion of low melting point component to the base material, the liquid film thickness decreases until disappears, and then through a certain time of heat preservation to make the composition homogenization, the generation of liquid phase clamps the intermediate diffusion interlayer material between the connected surfaces, and a certain pressure is applied, or the self weight of the workpiece is relied on to make the mutual contact. However, since the chip itself is light in quality, it is insufficient to meet the requirements, and the chip is easy to deviate along with the reflow furnace track, so that the welding effect is poor.

[0003] At present, most of the reflow ovens are not only used for diffusion welding, in order to improve the production efficiency, there is a multi-cavity structure, so that it is easy to deviate in the transmission process, and the manual placement of the pressing block is easy to deviate each time, therefore, it is urgent to design a structure which can solve the above problems. SUMMARY

[0004] In view of the above problems existing in the prior art, the clamp for welding is provided.

[0005] The specific technical scheme is as follows:

[0006] A clamp for welding mainly comprises: a fixed frame, a chip frame, a pressing block frame, a pressing block and a fastening assembly.

[0007] Both ends of the chip frame are clamped in the fixed frame, the pressing block frame is located on the side of the chip frame away from the fixed frame, the fastening assembly is sequentially arranged in the pressing block frame, the chip frame and the fixed frame, the chip frame is provided with a chip hole corresponding to the chip, the pressing block frame is provided with a pressing block hole corresponding to the chip hole, and the pressing block is inserted into the chip hole and the pressing block hole.

[0008] The clamp for welding has the following characteristics: the fixed frame has a single pipe positioning groove.

[0009] The clamp for welding has the following characteristics: both ends of the chip frame are provided with clamping grooves, and the clamping grooves are clamped with both ends of the fixed frame.

[0010] The clamp for welding has the following characteristics: the fixed frame is provided with a first positioning hole, the chip frame is provided with a second positioning hole, the pressing block frame is provided with a third positioning hole, and the first positioning hole, the second positioning hole and the third positioning hole are correspondingly arranged.

[0011] The welding fixture described above also has the feature that the fastening assembly includes a fixing post;

[0012] The fixing post is a stepped post, which includes a first section, a middle section and a third section with different diameters. The diameter of the middle section is larger than the diameters of the first section and the third section. The first section is inserted into the first positioning hole and the second positioning hole, and the third section is inserted into the third positioning hole.

[0013] The welding fixture described above also has the following feature: the third section is provided with an external thread, and the third section is fitted with a locking element.

[0014] The welding fixture described above also has the following feature: the pressure block is a square column.

[0015] The welding fixture described above also has the feature that the cross-sectional dimensions of the pressure block are the same as the dimensions of the chip.

[0016] The welding fixture described above also has the following feature: the single-sided dimensions of the chip hole and the pressure block hole are 0.05mm to 0.15mm larger than the single-sided dimensions of the chip.

[0017] The welding fixture described above also has the feature that the weight of the pressure block is proportional to the size of the chip.

[0018] The positive effects of the above technical solution are:

[0019] This utility model provides a welding fixture that places the board to be welded in a fixed frame, presses the chip frame in the fixed frame, and sequentially inserts the solder sheet and chip into the chip hole of the chip frame. A pressure block passes through the pressure block hole and the chip hole, pressing the chip. The entire fixture is then placed in a reflow oven for welding. During welding, the contact between the chip and the board to be welded is made tighter. More importantly, it prevents the solder sheet and chip from moving and shifting, thus avoiding the welding abnormalities caused by shifting in the prior art. It can reduce the void rate on the chip and the single tube frame, effectively shorten the welding time, improve the welding yield and welding efficiency, and is easy to operate and has a simple structure. Attached Figure Description

[0020] Figure 1 A schematic diagram of the structure of the fixing frame provided by this utility model;

[0021] Figure 2 A schematic diagram of the chip frame provided by this utility model;

[0022] Figure 3 This is a schematic diagram of the structure of the pressure block frame provided by this utility model;

[0023] Figure 4 A schematic diagram of the structure of the fixing column provided by this utility model;

[0024] Figure 5 This is a schematic diagram of the welding fixture provided by this utility model.

[0025] In the attached diagram: 1. Fixing frame; 11. Single tube positioning groove; 101. First positioning hole; 2. Chip frame; 21. Chip hole; 202. Second positioning hole; 22. Card slot; 3. Pressing block frame; 31. Pressing block hole; 303. Third positioning hole; 4. Pressing block; 5. Fixing post; 51. First section; 52. Middle section; 53. Third section; 6. Nut; 10. Single tube frame. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below through embodiments and in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0027] The serial numbers assigned to components in this document, such as "first" and "second," are used only to distinguish the described objects and have no sequential or technical meaning. The terms "connection" and "linkage" used in this application, unless otherwise specified, include both direct and indirect connections (linkages). In the description of this utility model, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and for 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. Therefore, they should not be construed as limitations on this utility model.

[0028] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0029] Please see Figures 1 to 5This utility model discloses a welding fixture, including: a fixing frame 1, a chip frame 2, a pressure block frame 3, a pressure block 4, and a fastening assembly;

[0030] The two ends of the chip frame 2 are secured to the fixing frame 1. The pressure block frame 3 is located on the side of the chip frame 2 away from the fixing frame 1. The fastening components are sequentially inserted through the pressure block frame 3, the chip frame 2, and the fixing frame 1. The chip frame 2 is provided with a chip hole 21 corresponding to the chip (not shown in the figure). The pressure block frame 3 is provided with a pressure block hole 31 corresponding to the chip hole 21. The pressure block 4 is inserted into the chip hole 21 and the pressure block hole 31.

[0031] The fixing frame 1 has a single-tube positioning slot 11. The single-tube positioning slot 11 is used to place the board to be soldered, such as a single-tube frame (a single-tube power module) 10. The internal shape of the single-tube positioning slot 11 is adapted to the external shape of the single-tube frame 10 to limit the single-tube frame 10, with a single-sided limiting margin ≤ 0.3mm. Optionally, in this embodiment, one or two single-tube positioning slots 11 are provided in one fixing frame 1, or even more. One single-tube frame 10 is placed in each single-tube positioning slot 11. Each single-tube frame 10 has a position where a chip needs to be soldered. Each single-tube frame 10 has a row of positions where a chip needs to be soldered, with a total of ten positions in a row. Since the chip needs to be soldered with solder sheets, solder sheets must also be placed below the chip.

[0032] The chip frame 2 has slots 22 at both ends, which engage with the two ends of the fixing frame 1. The slots 22 can engage the two ends of the chip frame 2 with the two sides of the fixing frame 1, so that the chip frame 2 and the fixing frame 1 are tightly connected and do not loosen.

[0033] The fixing frame 1 is provided with a first positioning hole 101, the chip frame 2 is provided with a second positioning hole 202, and the pressing block frame 3 is provided with a third positioning hole 303. The first positioning hole 101, the second positioning hole 202, and the third positioning hole 303 are correspondingly provided. Specifically, the first positioning hole 101, the second positioning hole 202, and the third positioning hole 303 are the same size and corresponding in position to ensure that their positions are the same and that they are firmly fixed. Optionally, in this embodiment, the first positioning hole 101, the second positioning hole 202, and the third positioning hole 303 are designed along the perimeter of the chip frame 2 to position the chip frame 2 and the pressing block frame 3.

[0034] Optionally, in this embodiment, the fastening assembly includes a fixing post 5;

[0035] The fixing post 5 is a stepped post, comprising a first section 51, a middle section 52, and a third section 53 with different diameters. The diameter of the middle section 52 is larger than the diameters of the first section 51 and the third section 53. The first section 51 is inserted into the first positioning hole 101 and the second positioning hole 202, and the third section 53 is inserted into the third positioning hole 303. Specifically, the first section 51 connects and positions the chip frame 2 and the fixing frame 1, and ensures that the chip frame 2 and the fixing frame 1 are tightly fitted together. The third section 53 has external threads and is fitted with a locking element such as a nut 6. The middle section 52 has the largest diameter, therefore its diameter is larger than that of the first section 51, forming a first stepped surface that can hold the chip frame 2 in place. The diameter of the middle section 52 is larger than that of the third section 53, forming a second stepped surface that can hold the pressure block frame 3 in place, thus maintaining a certain distance between the chip frame 2 and the pressure block frame 3. The third segment 53 of the fixing post 5 is inserted into the third positioning hole 303. The diameter of the third segment 53 is slightly smaller than that of the third positioning hole 303 and is locked in place on the second stepped surface to keep the pressure block frame 3 horizontal. Then, a locking device is used to lock the third segment 53 at the point where it exits the third positioning hole 303 to fix it in place. The first segment 51 of the fixing post 5 is inserted into the first positioning hole 101 and the second positioning hole 202. The diameter of the first segment 51 is slightly smaller than that of the second positioning hole 202 and is locked in place on the first stepped surface to keep the chip frame 2 horizontal. The length of the first segment 51 of the fixing post 5 is equal to the sum of the thickness of the fixing frame 1 and the chip frame 2, so it generally will not loosen when placed horizontally. The threaded nut on the third segment 53 of the fixing post 5 is mainly for ease of use without disassembly, allowing the fixing post 5 and the pressure block frame 3 to be integrated. The first section 51 of the fixed column 5 is not equipped with a locking mechanism because a single tube frame 10 needs to be placed each time it is installed. If it is locked, it will be difficult to place. On the other hand, if a nut is installed at the lower end of the first section 51 of the fixed column 5, four nuts will be suspended at the lower end of the fixed frame 1, which is not conducive to reflow oven heating.

[0036] Optionally, in this embodiment, both the chip hole 21 and the pressure block hole 31 are square holes; therefore, the pressure block is a square pillar. The positions of the chip hole 21 and the pressure block hole 31 are designed according to the position of the chip, and the shapes of the chip hole 21 and the pressure block hole 31 are designed according to the shapes of the chip and the solder sheet. The shapes of the chip hole 21 and the pressure block hole 31 are adapted to the shapes of the chip and the solder sheet.

[0037] Optionally, the cross-sectional dimensions of the pressure block 4 are the same as the dimensions of the chip.

[0038] The weight of the pressure block 4 is proportional to the size of the chip. Different chip sizes require different pressures, ranging from 0.01 to 0.5 MPa, therefore, the weight of the pressure block 4 also varies accordingly.

[0039] Optionally, the single-sided dimensions of the chip hole 21 and the pressing block hole 31 are 0.05mm to 0.15mm larger than the single-sided dimensions of the chip. The size of the pressing block 4 is the same as the size of the chip, and the single-sided dimensions of the chip hole 21 and the pressing block hole 31 are 0.05mm to 0.15mm larger than the single-sided dimensions of the pressing block 4.

[0040] Optionally, in this embodiment, the chip positions of the two single-tube frames 10 placed in the two single-tube positioning slots 11 are close to one end. Therefore, placing the chip positions of the two single-tube frames 10 placed in the two single-tube positioning slots 11 close to each other can reduce the width of the chip frame 2 and the pressing block frame 3. The chip hole 21 and the pressing block hole 31 are both provided in two rows, with ten holes in each row. Of course, this is only an example and is not intended to limit the present invention.

[0041] This utility model provides a welding fixture in which the board to be welded is placed in a fixed frame 1, a chip frame 2 is pressed on the fixed frame 1, and solder sheets and chips are sequentially inserted into the chip holes 21 of the chip frame 2. A pressure block 4 passes through the pressure block hole 31 and the chip hole 21 and presses on the chip. Then the entire fixture is placed in a reflow oven for welding. During welding, the contact between the chip and the board to be welded is made tighter. More importantly, it prevents the solder sheets and chips from moving and shifting, thus avoiding the welding abnormalities caused by shifting in the prior art. It can reduce the void rate on the chip and the single tube frame, effectively shorten the welding time, improve the welding yield and welding efficiency, and is easy to operate and has a simple structure.

[0042] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0043] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A welding fixture, characterized in that, include: Fixed frame, chip frame, pressure block frame, pressure block and fastening assembly; The two ends of the chip frame are secured to the fixing frame. The pressure block frame is located on the side of the chip frame away from the fixing frame. The fastening component is sequentially inserted through the pressure block frame, the chip frame, and the fixing frame. The chip frame is provided with a chip hole corresponding to the chip. The pressure block frame is provided with a pressure block hole corresponding to the chip hole. The pressure block is inserted into the chip hole and the pressure block hole.

2. The welding fixture according to claim 1, characterized in that, The fixed frame has a single-tube positioning groove.

3. The welding fixture according to claim 1, characterized in that, The chip frame has slots at both ends, which engage with the two ends of the fixing frame.

4. The welding fixture according to claim 1, characterized in that, The fixing frame is provided with a first positioning hole, the chip frame is provided with a second positioning hole, and the pressure block frame is provided with a third positioning hole, with the first positioning hole, the second positioning hole, and the third positioning hole being provided correspondingly.

5. The welding fixture according to claim 4, characterized in that, The fastening assembly includes a fixing post; The fixing post is a stepped post, which includes a first section, a middle section and a third section with different diameters. The diameter of the middle section is larger than the diameters of the first section and the third section. The first section is inserted into the first positioning hole and the second positioning hole, and the third section is inserted into the third positioning hole.

6. The welding fixture according to claim 5, characterized in that, The third section is provided with external threads, and the third section is fitted with a locking element.

7. The welding fixture according to any one of claims 1 to 6, characterized in that, The pressing block is a square column.

8. The welding fixture according to any one of claims 1 to 6, characterized in that, The cross-sectional dimensions of the pressing block are the same as the dimensions of the chip.

9. The welding fixture according to any one of claims 1 to 6, characterized in that, The single-sided dimension of the chip hole and the pressing block hole is 0.05mm to 0.15mm larger than the single-sided dimension of the chip.

10. The welding fixture according to any one of claims 1 to 6, characterized in that, The weight of the pressure block is proportional to the size of the chip.

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