A fixture for preventing incomplete soldering

Abstract

This utility model relates to the field of power semiconductor module manufacturing technology, specifically disclosing an anti-cold solder joint fixture, including a base plate with a positioning groove on its upper surface; a welding positioning plate positioned directly above the base plate, with multiple strip-shaped and rectangularly arrayed limiting slots through its upper surface; and a cover plate with multiple sets of evenly distributed mounting holes on its upper surface, each mounting hole containing a push rod. A limiting ring is fixedly connected to the outer wall of each push rod, and a spring is sleeved on the outer wall of the push rod at the upper end of the limiting ring. This three-stage positioning structure achieves precise alignment between the substrate and the terminals. The spring-driven push rod group provides dynamic downward pressure, overcoming terminal suspension caused by solder surface tension. The pressure plate works in concert to ensure uniform welding pressure across multiple terminals, and the design of the paddle and groove enhances the substrate's resistance to displacement, significantly reducing the cold solder joint rate and improving welding consistency and product yield.

Description

Technical Field

[0001] This utility model relates to the field of power semiconductor module manufacturing technology, and specifically discloses a fixture for preventing cold solder joints. Background Technology

[0002] In the field of power semiconductor module manufacturing, the welding quality of DBC (Direct Copper Bonding) substrates and terminals directly affects the electrical performance and reliability of the module. During the welding process, the solder melts at high temperature to form a liquid state, relying on surface tension to wet the connection surface. Due to the light weight of the terminals and the effect of the liquid surface tension of the solder, the terminals tend to float on the surface of the molten solder layer and have difficulty overcoming the surface tension to sink to the preset position, resulting in insufficient contact area at the welding interface or local non-bonding.

[0003] Traditional processes rely on manual adjustment or simple positioning fixtures, which makes it difficult to accurately control the bonding state between the terminals and the DBC substrate, easily leading to poor soldering defects, reducing product yield and long-term service stability. Utility Model Content

[0004] This invention proposes an anti-cold solder joint fixture, which achieves precise alignment between the substrate and the terminal through a three-level positioning structure. The spring-driven push rod group provides dynamic downward pressure to overcome the terminal suspension caused by the surface tension of the solder, significantly reducing the cold solder joint rate and improving welding consistency and product yield.

[0005] This utility model is implemented as follows: a fixture for preventing incomplete soldering includes:

[0006] The base plate has a positioning groove on its upper end surface;

[0007] A welding positioning plate is disposed directly above the base plate, and the upper surface of the welding positioning plate is provided with multiple strip-shaped and rectangularly arrayed limiting slots.

[0008] The cover plate has multiple sets of evenly distributed mounting holes on its upper surface. The mounting holes are equidistant from each other in the left and right directions. Each mounting hole has a push rod inside it. A limit ring is fixedly connected to the outer wall of the push rod, and a spring located at the upper end of the limit ring is sleeved on the outer wall of the push rod.

[0009] As a preferred embodiment of the anti-cold soldering fixture of this utility model, each set of mounting holes is provided with a pressure plate at the upper end, and the outer wall of the pressure plate is provided with multiple through holes, the number, size and layout of the through holes being the same as those of the mounting holes.

[0010] As a preferred embodiment of the anti-cold welding fixture of this utility model, two connecting holes are provided on both the left and right sides of the base plate, and connecting posts are threaded into the interior of each of the multiple connecting holes. The cover plate is slidably sleeved on the outer wall of the multiple connecting posts, and locking nuts are threaded into the top of each of the multiple connecting posts.

[0011] As a preferred embodiment of the anti-false welding fixture of this utility model, a fixing post is provided through the four corners of the upper end face of the welding positioning plate, and a fixing hole is provided at the four corners of the upper end face of the base plate, and the four fixing posts are respectively inserted into the four fixing holes.

[0012] As a preferred embodiment of the anti-false welding fixture of this utility model, the upper end of the base plate is rotatably connected to multiple paddles on both the front and rear sides, and the multiple paddles extend to the inner side and above the positioning groove.

[0013] As a preferred embodiment of the anti-false welding fixture of this utility model, the upper end of the base plate has two grooves on both the front and rear sides that communicate with the inner side of the positioning groove.

[0014] As a preferred embodiment of the anti-false welding fixture of this utility model, the outer walls of the welding positioning plate and the cover plate are provided with a hollow structure arranged in an array with rectangular units.

[0015] The beneficial effects of this utility model are:

[0016] This fixture achieves precise alignment of the substrate and terminals through a three-level positioning structure. The spring-driven push rod group provides dynamic downward pressure to overcome the terminal suspension caused by the surface tension of the solder. The pressure plate works together to ensure the uniformity of welding pressure for multiple terminals. The design of the paddle and groove enhances the substrate's resistance to displacement, significantly reducing the rate of poor solder joints and improving welding consistency and product yield. Attached Figure Description

[0017] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0018] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0019] Figure 2 This is a top view of the base plate structure of this utility model;

[0020] Figure 3 This is a structural diagram of the welding positioning plate of this utility model;

[0021] Figure 4 This is a top view of the cover plate of this utility model;

[0022] Figure 5 This is a partially enlarged cross-sectional view of the present invention.

[0023] The markings in the diagram are: 1. Base plate; 2. Positioning groove; 3. Welding positioning plate; 4. Limiting groove; 5. Cover plate; 6. Mounting hole; 7. Top rod; 8. Limiting ring; 9. Spring; 10. Pressure plate; 11. Connecting hole; 12. Connecting column; 13. Locking nut; 14. Fixing column; 15. Fixing hole; 16. Paddle; 17. Groove; 18. Hollow structure. Detailed Implementation

[0024] The present invention will be further described below with reference to the accompanying drawings and specific embodiments to aid in understanding its content. Unless otherwise specified, the methods used in this invention are conventional methods; the raw materials and apparatus used, unless otherwise specified, are conventional commercially available products.

[0025] Please see Figure 1-5 A fixture for preventing incomplete soldering, comprising:

[0026] The base plate 1 has a positioning groove 2 on its upper surface;

[0027] The welding positioning plate 3 is set directly above the base plate 1. The upper end surface of the welding positioning plate 3 has multiple strip-shaped and rectangularly arrayed limiting slots 4.

[0028] The cover plate 5 has multiple sets of evenly distributed mounting holes 6 on its upper surface. The mounting holes 6 are equidistant from each other in the left and right directions. Each mounting hole 6 has a push rod 7 inside it. The outer wall of the push rod 7 is fixedly connected to a limit ring 8. A spring 9 located at the upper end of the limit ring 8 is sleeved on the outer wall of the push rod 7.

[0029] In this embodiment: the DBC substrate is initially fixed in the positioning groove 2 of the base plate 1. The welding positioning plate 3 is vertically installed above the base plate 1 through the fixing post 14, and its limiting groove 4 is aligned with the welding position of the substrate. After the terminal is inserted into the limiting groove 4, the cover plate 5 is added. The push rod 7 passes through the mounting hole 6 and abuts against the top of the terminal. The spring 9 is pressed and pushes the limiting ring 8 to make the push rod continuously press down on the terminal, eliminating the suspension caused by the solder tension. The pressure plate 10 covers multiple sets of push rods to achieve uniform pressure. The connecting post 12 and the locking nut 13 lock the cover plate. The paddle 16 fixes the DBC substrate. The groove 17 facilitates the removal and placement of the substrate. The hollow structure 18 reduces weight and improves heat dissipation efficiency, ultimately ensuring that the terminal and the DBC substrate fit together with zero gap.

[0030] As a technical optimization of this utility model, a pressure plate 10 is provided at the upper end of each set of mounting holes 6. The outer wall of the pressure plate 10 is provided with multiple through holes, and the number, size and layout of the through holes are the same as those of the mounting holes 6.

[0031] In this embodiment: the through hole of the pressure plate 10 is aligned with the mounting hole 6, covering all the push rods 7 in the same group, so as to realize that a single pressure plate can simultaneously press down multiple push rods 7, eliminating pressure deviation of multiple terminals.

[0032] As a technical optimization of this utility model, two connecting holes 11 are opened on both the left and right sides of the base plate 1, and connecting posts 12 are threadedly connected inside the multiple connecting holes 11. The cover plate 5 is slidably sleeved on the outer wall of the multiple connecting posts 12, and locking nuts 13 are threadedly connected to the top of the multiple connecting posts 12.

[0033] In this embodiment: the connecting column 12 passes through the base plate 1 and the cover plate 5, and the locking nut 13 is tightened to fix the overall structure, providing detachable rigid support.

[0034] As a technical optimization of this utility model, a fixing post 14 is provided through the four corners of the upper end face of the welding positioning plate 3, and a fixing hole 15 is provided at the four corners of the upper end face of the base plate 1. The four fixing posts 14 are respectively inserted into the four fixing holes 15.

[0035] In this embodiment: the fixing post 14 is inserted into the fixing hole 15 of the base plate 1 to ensure the vertical alignment accuracy between the welding positioning plate 3 and the base plate 1.

[0036] As a technical optimization of this utility model, multiple paddles 16 are rotatably connected to both the front and rear sides of the upper end of the base plate 1, and the multiple paddles 16 extend to the upper inner side of the positioning groove 2.

[0037] In this embodiment: the paddle 16 rotates to the position groove 2 to limit the edge of the DBC substrate and prevent it from shifting due to welding heat deformation.

[0038] As a technical optimization of this utility model, two grooves 17 communicating with the inner side of the positioning groove 2 are opened on both the front and rear sides of the upper end of the base plate 1.

[0039] In this embodiment: the groove 17 connects to the side wall of the positioning groove 2, which facilitates the insertion of tools to pry the substrate and solves the problem of high-temperature adhesion and material removal.

[0040] As a technical optimization of this utility model, the outer walls of both the welding positioning plate 3 and the cover plate 5 are provided with hollow structures 18 arranged in an array with rectangular units.

[0041] In this embodiment, the hollow structure 18 is distributed in a rectangular array on the welding positioning plate 3 and the cover plate 5, which reduces the overall weight of the fixture and accelerates heat dissipation.

[0042] The working principle and usage process of this utility model are as follows: During operation, the DBC substrate is first inserted into the positioning groove 2 of the base plate 1, and the paddle 16 is rotated to press the edge of the substrate; the fixing post 14 is inserted into the fixing hole 15 of the base plate 1 to fix and weld the positioning plate 3; the terminal is vertically inserted into the limiting groove 4 to align the substrate solder joint; after the cover plate 5 is covered, the top rod 7 is inserted into the mounting hole 6 so that its bottom end contacts the top of the terminal; the pressure plate 10 is placed on the upper end of the top rod 7 in the same group, and the cover plate 5 is pressed down to compress the spring 9 and store force. The locking nut 13 at the top of the connecting post 12 is tightened to lock the cover plate, and the spring 9 releases its elastic force to push the limiting ring 8, so that the top rod 7 continues to press the terminal downward until the solder solidifies.

[0043] In the description of this utility model, it should be understood that the terms "left", "right", "up", "down", "top", "bottom", "front", "back", "inner", "outer", "back", "middle", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and 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.

[0044] However, the above description is only a specific embodiment of this utility model and should not be construed as limiting the scope of implementation of this utility model. Therefore, any substitution of equivalent components or equivalent changes and modifications made in accordance with the scope of protection of this utility model should still fall within the scope of the claims of this utility model.

Claims

1. A false solder prevention jig, characterized by: include: The base plate (1) has a positioning groove (2) on its upper end surface. A welding positioning plate (3) is set directly above the base plate (1). The upper surface of the welding positioning plate (3) is provided with multiple limiting slots (4) that are strip-shaped and arranged in a rectangular array. The cover plate (5) has multiple sets of mounting holes (6) evenly distributed in the front and back on its upper surface. The multiple sets of mounting holes (6) are equidistant in the left and right directions. Each of the multiple mounting holes (6) is provided with a push rod (7). The outer wall of the push rod (7) is fixedly connected to a limit ring (8). The outer wall of the push rod (7) is sleeved with a spring (9) located at the upper end of the limit ring (8).

2. The false solder prevention jig according to claim 1, characterized by: Each set of mounting holes (6) is provided with a pressure plate (10) at the upper end. The outer wall of the pressure plate (10) is provided with multiple through holes. The number, size and layout of the through holes are the same as those of the mounting holes (6).

3. The false solder prevention jig according to claim 1, characterized by: Two connecting holes (11) are opened on both the left and right sides of the base plate (1). Connecting posts (12) are threaded inside the multiple connecting holes (11). The cover plate (5) is slidably sleeved on the outer wall of the multiple connecting posts (12). Locking nuts (13) are threaded to the top of the multiple connecting posts (12).

4. The false solder prevention jig according to claim 1, characterized by: The upper end face of the welding positioning plate (3) is provided with a fixing post (14) through the four corners, and the upper end face of the base plate (1) is provided with a fixing hole (15) through the four corners. The four fixing posts (14) are respectively inserted into the four fixing holes (15).

5. The anti-pseudo soldering jig according to claim 1, wherein: The upper end of the base plate (1) is rotatably connected to multiple paddles (16) on both the front and rear sides, and the multiple paddles (16) extend to the upper inner side of the positioning groove (2).

6. The anti-pseudo soldering jig according to claim 1, wherein: The upper end of the base plate (1) has two grooves (17) on both the front and rear sides that communicate with the inner side of the positioning groove (2).

7. The anti-pseudo soldering jig according to claim 1, characterized in that: The outer walls of the welding positioning plate (3) and the cover plate (5) are provided with hollow structures (18) arranged in a rectangular array.

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