Insulated gate bipolar transistor (IGBT) pin capable of preventing tin climbing

Abstract

The utility model discloses an anti-tin-climbing IGBT pin, which comprises a pin rod and a base, and is characterized in that the base comprises a bottom plate and a mounting rod coaxially arranged on the top surface of the bottom plate, the middle part of the mounting rod is provided with a coaxially arranged mounting hole, the top of the mounting hole is communicated with the top surface of the mounting rod, and the pin rod is arranged on the bottom plate. The bottom of the mounting hole is not communicated with the bottom surface of the bottom plate, and the bottom of the needle rod is mounted in the mounting hole. According to the utility model, the aesthetic property of the IGBT pin is improved, the tin climbing phenomenon is prevented, and the tin soldering cost is lower.

Description

Technical Field

[0001] The utility model relates to an IGBT plug pin, in particular to an IGBT plug pin capable of preventing tin creeping. Background Art

[0002] IGBT, insulated gate bipolar transistor, is a composite fully controlled voltage-driven power semiconductor device composed of BJT (bipolar transistor) and MOS (insulated gate field effect transistor), which has the advantages of high input impedance of MOSFET and low on-state voltage drop of GTR. Among them, IGBT pin (pin pin) is a quick-plug structure used to realize IGBT modular connection. Generally, one end of the IGBT pin is soldered to the circuit board through solder, and the other end is used to plug and match with the connection mechanism.

[0003] In the prior art, in order to prevent tin creeping, such as application number: 202222537181.4, patent name: an anti-tin creeping IGBT pin, which is provided with a clamping seal at the connection between the pin and the base to prevent tin creeping. The original soldering method is to use wave soldering, and the soldering temperature is 245°C. In this way, under normal circumstances, the solder will not creep out of the gap. However, now the soldering method has been changed to reflow soldering, and the soldering temperature is 260°C. The effect of the original sealing method is not very ideal, and tin creeping will occur.

[0004] In order to deal with the tin creeping situation and ensure the firmness of the solder, for example, 1g of tin was enough for a firm soldering before, but due to the tin creeping problem, 2g of tin is needed for soldering, 1g of tin for welding, and another 1g of tin for tin creeping. In this way, the tin creeping may climb to the top of the pin, which not only affects the appearance, but also causes the product to be unqualified. At the same time, the amount of tin used is high and the cost is even higher. Therefore, how to solve the above technical problems is the direction that technicians in this field need to work hard on. Summary of the invention

[0005] The utility model aims to provide an IGBT pin with anti-tin creeping function. By using the structure, the pin is suitable for the reflow soldering process, and the tin creeping phenomenon will not occur. The pin is more beautiful, the amount of tin used during soldering is reduced, and the soldering cost is reduced.

[0006] In order to achieve the above-mentioned purpose, the technical solution adopted by the utility model is: an anti-tin creeping IGBT pin, including a pin rod and a base, the base including a bottom plate and a mounting rod coaxially arranged on the top surface of the bottom plate, a coaxially arranged mounting hole is provided in the middle of the mounting rod, the top of the mounting hole is connected to the top surface of the mounting rod, the bottom of the mounting hole is not connected to the bottom surface of the bottom plate, and the bottom of the pin rod is installed in the mounting hole.

[0007] In the above technical solution, the bottom surface of the bottom plate is a plane.

[0008] In the above technical solution, a tapered hole which is larger at the top and smaller at the bottom is provided at the bottom of the mounting hole, and the tapered hole is coaxially arranged with the mounting hole.

[0009] In the above technical solution, the bottom of the tapered hole is arranged close to the top surface of the bottom plate.

[0010] In the above technical solution, the bottom of the tapered hole is inserted into the bottom plate, and there is a vertical distance between the bottom of the tapered hole and the bottom surface of the bottom plate.

[0011] In the above technical solution, a guide head with a small outside and a large inside is respectively provided at both ends of the needle rod, one end of the needle rod is inserted into the mounting hole, and the guide head at the bottom of the needle rod is inserted into the tapered hole, and the guide head is tightly fitted with the tapered hole.

[0012] In the above technical solution, the needle rod is tightly matched with the mounting hole.

[0013] In the above technical solution, the cross-sections of the needle rod and the guide head are square.

[0014] In the above technical solution, the outer edge of the bottom of the mounting rod is connected to the top surface of the bottom plate via an arc surface.

[0015] Due to the application of the above technical solution, the utility model has the following advantages compared with the prior art:

[0016] 1. The bottom of the bottom plate of the utility model is not connected to the mounting hole. In this way, in the process of high-temperature reflow soldering, compared with the previous method of using holes, it can effectively prevent the phenomenon of tin climbing, which not only improves the aesthetics, but also reduces the amount of tin and reduces the cost;

[0017] 2. Compared with the solder structure with holes, the utility model has better welding firmness and stability, and stronger tensile strength;

[0018] 3. In the utility model, a tapered hole is provided at the bottom of the mounting hole, so that when the pin is plugged into the mounting hole, the tapered hole is used to press against the bottom of the needle rod, thereby increasing the connection strength between the two and ensuring the overall firmness and stability of the pin. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the structure of the first embodiment of the present utility model;

[0020] Figure 2 yes Figure 1 A top view of

[0021] Figure 3 It is a schematic cross-sectional structural diagram of the base in the first embodiment of the utility model.

[0022] Among them: 1. needle rod; 2. base; 3. bottom plate; 4. mounting rod; 5. mounting hole; 6. tapered hole; 7. guide head; 8. curved surface. DETAILED DESCRIPTION

[0023] The utility model is further described below in conjunction with the accompanying drawings and embodiments:

[0024] Example 1: See Figures 1 to 3 As shown, an anti-tin creeping IGBT pin includes a pin rod 1 and a base 2, wherein the base 2 includes a bottom plate 3 and a mounting rod 4 coaxially arranged on the top surface of the bottom plate 3, a coaxially arranged mounting hole 5 is provided in the middle of the mounting rod 4, the top of the mounting hole 5 is connected to the top surface of the mounting rod 4, the bottom of the mounting hole 5 is not connected to the bottom surface of the bottom plate 3, and the bottom of the pin rod 1 is installed in the mounting hole 5.

[0025] The bottom surface of the bottom plate is a plane.

[0026] In this embodiment, when the pins are soldered, the bottom of the bottom plate and the circuit board are reflowed with solder, and the bottom of the bottom plate is fixed to the circuit board by soldering. In this embodiment, the mounting hole is a blind hole, which is only connected to the top of the mounting rod and not to the bottom surface of the bottom plate. In this way, when soldering, there is no channel for the solder to climb upwards, which can effectively prevent the occurrence of tin climbing. This is more aesthetically pleasing, and there is no problem of tin climbing. There is no need to reserve the amount of tin for tin climbing, which reduces costs. In addition, the stability and firmness of the welding are better, and the tensile strength is stronger.

[0027] See also Figure 1 , 3 As shown, a tapered hole 6 which is larger at the top and smaller at the bottom is provided at the bottom of the mounting hole 5, and the tapered hole is coaxially arranged with the mounting hole.

[0028] The needle bar 1 is tightly fitted with the mounting hole 5. A guide head 7 with a small outside and a large inside is respectively provided at both ends of the needle bar 1. One end of the needle bar is inserted into the mounting hole, and the guide head at the bottom of the needle bar is inserted into the tapered hole. The guide head is tightly fitted with the tapered hole. The top width of the guide head at the top of the needle bar is smaller than the bottom width. The bottom width of the guide head at the bottom of the needle bar is smaller than the top width.

[0029] In the previous structure, the mounting hole is a through hole, which provides space for solder to climb up. The gap between the mounting hole and the needle rod can be filled and welded with solder to ensure the connection strength between the two. In this embodiment, the needle rod and the mounting hole are tightly matched to ensure the connection strength between the two. Furthermore, a tapered hole is set at the bottom of the mounting hole, and the guide head is also inserted into the tapered hole. The guide head and the tapered hole are also tightly matched, which can effectively ensure the connection strength between the two, which is stronger than the strength of the gap filled with solder in the past. The guide head at the top of the needle rod is used for guidance when plugging with other components.

[0030] There are two types of positions of the conical hole in the area: the first type: the bottom of the conical hole is arranged close to the top surface of the bottom plate. The second type: the bottom of the conical hole is inserted into the bottom plate, and there is a vertical spacing between the bottom of the conical hole and the bottom surface of the bottom plate.

[0031] In this embodiment, the position of the tapered hole adopts the second method, so that the length of the mounting hole is longer, the contact area between the needle rod and the mounting hole is larger, and the connection strength between the two is stronger.

[0032] See also Figure 1 , 2 As shown, the cross-section of the needle bar and the guide head is square. Among them, the mounting hole is a cylindrical structure, the cross-section of the needle bar and the guide head is square, and the top and bottom of the guide head are both square, which is convenient for processing the needle bar. The outer diameter of the needle bar will be slightly larger than the outer diameter of the mounting hole. Then, when installing, the needle bar is directly inserted into the mounting hole through the guide head, and the two are squeezed and deformed to achieve a tight fit.

[0033] See also Figure 1 , 3 As shown, the outer edge of the bottom of the mounting rod 4 is connected to the top surface of the bottom plate 3 via an arc surface 8. This prevents cracking at the connection between the mounting rod and the bottom plate during processing, facilitates processing, and is more aesthetically pleasing. In this embodiment, the mounting rod and the bottom plate are an integrated structure.

Claims

1. An anti-tin creeping IGBT pin, comprising a pin bar and a base, characterized in that: The base includes a bottom plate and a mounting rod coaxially arranged on the top surface of the bottom plate, a coaxial mounting hole is provided in the middle of the mounting rod, the top of the mounting hole is connected to the top surface of the mounting rod, the bottom of the mounting hole is not connected to the bottom surface of the bottom plate, and the bottom of the needle rod is installed in the mounting hole.

2. The anti-tin creeping IGBT pin according to claim 1, characterized in that: The bottom surface of the bottom plate is a plane.

3. The anti-tin creeping IGBT pin according to claim 1, characterized in that: A tapered hole that is larger at the top and smaller at the bottom is provided at the bottom of the mounting hole, and the tapered hole is coaxially arranged with the mounting hole.

4. The anti-tin creeping IGBT pin according to claim 3, characterized in that: The bottom of the tapered hole is arranged close to the top surface of the bottom plate.

5. The anti-tin creeping IGBT pin according to claim 3, characterized in that: The bottom of the tapered hole is inserted into the bottom plate, and a vertical distance is provided between the bottom of the tapered hole and the bottom surface of the bottom plate.

6. The anti-tin creeping IGBT pin according to claim 3, characterized in that: A guide head with a small outside and a large inside is respectively provided at both ends of the needle rod, one end of the needle rod is inserted into the mounting hole, and the guide head at the bottom of the needle rod is inserted into the tapered hole, and the guide head is tightly fitted with the tapered hole.

7. The anti-tin creeping IGBT pin according to claim 1 or 6, characterized in that: The needle rod is tightly matched with the mounting hole.

8. The anti-tin creeping IGBT pin according to claim 6, characterized in that: The cross sections of the needle bar and the guide head are square.

9. The anti-tin creeping IGBT pin according to claim 1, characterized in that: The outer edge of the bottom of the mounting rod is connected to the top surface of the bottom plate via an arc surface.

Images