Metal needle for connecting drive circuit board and stamping die thereof

Abstract

This invention belongs to the field of power semiconductor manufacturing technology, and particularly relates to a metal pin for connecting a driver circuit board. The pin includes a pin body and a snap-fit ​​structure. The snap-fit ​​structure includes an upper spring and a lower spring. A receiving cavity is formed on the middle side of the pin body, and the upper and lower springs are disposed within the receiving cavity. The distance between the upper and lower springs is less than the thickness of the driver circuit board. Beneficial effects: The metal pin for connecting a driver circuit board of this invention is snapped onto the driver circuit board through a snap-fit ​​structure, reducing soldering or bonding with the driver circuit board, improving product yield, reducing labor time and improving efficiency, facilitating assembly with the driver circuit board, and promoting the integration of intelligent power modules, in line with the trend of miniaturization of intelligent power modules.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of power semiconductor manufacturing, and particularly relates to a metal needle for connecting a drive circuit board and a stamping die thereof. BACKGROUND

[0002] The intelligent power module (IPM) is widely used in the fields of AC motor variable frequency speed regulation, DC motor chopper speed regulation, various high-performance power supplies such as UPS, induction heating, electric welding machine, active compensation, DC-DC, industrial electrical automation, etc., and has a broad market. The IPM is mainly composed of a shell, a main circuit board and a drive circuit board. The semiconductor power chip and other devices are welded on the metal-clad ceramic substrate, and are connected by bonding aluminum wires or other metals to form the main circuit board. The printed circuit board on which the integrated circuit chip and various devices are welded forms the drive circuit board.

[0003] The drive circuit board needs the electrical signal output by the main circuit board and also needs to send a drive signal to the main circuit board. The existing scheme (I) welds the metal needle on the main circuit board with solder, and then welds the metal needle with the drive circuit board to realize the communication between the main circuit board and the drive circuit board; or scheme (II) encapsulates the electrode terminal into the shell, and performs aluminum wire bonding between the main circuit board and the shell terminal and between the drive circuit board and the shell terminal, respectively, to communicate through the electrode terminal on the shell.

[0004] Scheme (I) needs to weld multiple metal needles at the same input / output terminal when manufacturing an intelligent power module with large power, in order to meet the current capacity requirement, and the welding operation is complicated, and only one of the metal needles is used for communication with the drive circuit board, which has no requirement on current flow. Scheme (II) needs to perform upper and lower bonding, and the process is complicated, and the PCB used for bonding requires high surface cleanliness, and needs to be cleaned after the drive circuit board is manufactured, and there is a risk of aluminum wire falling off even after cleaning. SUMMARY

[0005] To solve the problem of complicated operation of the signal connection structure between the drive circuit board and the main circuit board in the prior art, the present application provides a metal needle for connecting a drive circuit board and a stamping die thereof.

[0006] To solve the above technical problems, the technical scheme adopted by the present application is as follows: a metal needle for connecting a drive circuit board, comprising a needle body and a clamping structure, the clamping structure comprising an upper spring piece and a lower spring piece, a receiving cavity being formed in the side edge of the middle part of the needle body, the upper spring piece and the lower spring piece being arranged in the receiving cavity, and the distance between the upper spring piece and the lower spring piece being less than the thickness of the drive circuit board.

[0007] Preferably, there is an elastic space between the upper spring and the needle body, and there is also an elastic space between the lower spring and the needle body. This increases the deformation of the upper and lower springs and improves the reliability of their engagement with the drive circuit board.

[0008] Preferably, the working surfaces of the upper and lower spring contacts are arc surfaces that are close to each other. This ensures that the drive circuit board can make full contact with the upper and lower spring contacts after insertion and has a certain degree of reliability.

[0009] Preferably, both the upper and lower spring contacts have chamfered edges facing the insertion direction of the drive circuit board. This facilitates the insertion of the drive circuit board between the upper and lower spring contacts, effectively prevents stress concentration on the upper and lower spring contacts, and improves their service life.

[0010] Furthermore, the metal needle is made of copper or a copper alloy.

[0011] Furthermore, the snap-fit ​​structure is formed by stamping, which facilitates the processing and manufacturing of the metal needle.

[0012] Furthermore, the side of the drive circuit board is located within the receiving cavity, and several metal pins are secured to three adjacent sides of the drive circuit board via the snap-fit ​​structure. This ensures that the drive circuit board forms a drawer-shaped structure after being inserted into the snap-fit ​​structure, facilitating the assembly of the drive circuit board and effectively limiting its position.

[0013] A stamping die for manufacturing a metal needle as described above includes a first stamp and a second stamp. The first stamp includes a first punch, a second punch, and a third punch arranged sequentially. The first punch is I-shaped and mates with a receiving cavity. The second punch is located between an upper spring sheet and a lower spring sheet, both of which are located between the first and third punches. The second stamp includes a connecting block with a fourth punch, a fifth punch, and a sixth punch arranged sequentially on it. The fourth punch mates with the elastic space between the upper spring sheet and the needle body. The sixth punch mates with the elastic space between the lower spring sheet and the needle body. The fifth punch is located between the upper and lower spring sheets.

[0014] Preferably, an arc-shaped chamfer is provided between the third punch and the second punch; arc-shaped grooves are provided on both the top and bottom of the fifth punch. This facilitates the simultaneous formation of guide chamfers on the outer sides of the upper and lower spring sheets facing the insertion direction of the drive circuit board during the stamping of the first punch; and facilitates the simultaneous formation of arc surfaces where the working surfaces of the upper and lower spring sheets approach each other, as well as guide chamfers on both sides of the upper and lower spring sheets facing the insertion direction of the drive circuit board during the stamping of the second punch.

[0015] Beneficial effects: the metal needle of the application for connecting the drive circuit board, firstly, several metal needles are welded on the metal ceramic substrate of the existing main circuit board, then the drive circuit board is inserted into the clamping structure along the lead-in chamfer, at this time, the drive circuit board is located between the upper spring plate and the lower spring plate, the side edge of the drive circuit board is located in the accommodating cavity, and the several metal needles are clamped on the adjacent three edges of the drive circuit board through the clamping structure, so that the drive circuit board forms a drawer-shaped structure after being inserted into the clamping structure, which is convenient for the assembly of the drive circuit board and the position is well limited; the metal needle of the application for connecting the drive circuit board reduces welding or bonding with the drive circuit board, improves product yield, reduces working hours and improves efficiency; the metal needle of the application for connecting the drive circuit board is convenient for assembly with the drive circuit board, is conducive to the integration of the intelligent power module, conforms to the trend of miniaturization of the intelligent power module; the stamping die for manufacturing the metal needle has simple structure, ingenious design and low cost, and is convenient for stamping forming of the metal needle. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the application, and for those skilled in the art, other drawings can also be obtained without creative labor based on these drawings.

[0017] Figure 1 is a schematic diagram of the metal needle for connecting the drive circuit board of the application;

[0018] Figure 2 is Figure 1 is a partial enlarged schematic diagram of A in

[0019] Figure 3 is a schematic diagram of the metal needle for connecting the drive circuit board of the application and the assembly of the drive circuit board;

[0020] Figure 4 is a schematic diagram of the punch of the stamping die for manufacturing the metal needle of the application;

[0021] Figure 5 is a schematic diagram of the punch of the stamping die for manufacturing the metal needle of the application;

[0022] Figure 6 is a schematic diagram of the punch of the stamping die for manufacturing the metal needle of the application;

[0023] Figure 7 is a schematic diagram of the punch of the stamping die for manufacturing the metal needle of the application;

[0024] In the diagram: 1. Needle body; 11. Receiving cavity; 2. Snap-fit ​​structure; 21. Upper spring; 22. Lower spring; 23. Elastic space; 24. Guide chamfer; 3. Punch part one; 31. First punch block; 32. Second punch block; 33. Third punch block; 34. Arc chamfer; 4. Punch part two; 41. Connecting block; 42. Fourth punch block; 43. Fifth punch block; 44. Sixth punch block; 45. Arc groove; 5. Drive circuit board. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] Example 1

[0027] like Figures 1-3 As shown, a metal pin for connecting a drive circuit board includes a pin body 1 and a snap-fit ​​structure 2. The snap-fit ​​structure 2 includes an upper spring piece 21 and a lower spring piece 22. A receiving cavity 11 is formed on the middle side of the pin body 1. The upper spring piece 21 and the lower spring piece 22 are disposed in the receiving cavity 11. The distance between the upper spring piece 21 and the lower spring piece 22 is less than the thickness of the drive circuit board 5. In this embodiment, the side of the drive circuit board 5 is located in the receiving cavity 11. Several of the metal pins are snapped onto three adjacent sides of the drive circuit board 5 by the snap-fit ​​structure 2 to ensure that the drive circuit board 5 forms a drawer-shaped structure after being inserted into the snap-fit ​​structure 2, which facilitates the assembly of the drive circuit board 5 and effectively restricts its position.

[0028] To improve the reliability of the engagement between the snap-fit ​​structure 2 and the drive circuit board 5, in this embodiment, as follows: Figure 2 As shown, there is an elastic space 23 between the upper spring sheet 21 and the needle body 1, and there is also an elastic space 23 between the lower spring sheet 22 and the needle body 1; the working surfaces of the upper spring sheet 21 and the lower spring sheet 22 are arc surfaces that are close to each other; both the upper spring sheet 21 and the lower spring sheet 22 are provided with an inlet chamfer 24 in the insertion direction towards the drive circuit board 5.

[0029] The metal needle in this embodiment is made of copper or copper alloy; in order to facilitate the processing and manufacturing of the metal needle, the snap-fit ​​structure 2 is formed by stamping.

[0030] like Figures 4-7As shown, a stamping die for manufacturing the aforementioned metal needle includes a first stamp 3 and a second stamp 4, as follows: Figure 4 and Figure 6 As shown, the punch 3 includes a first punch 31, a second punch 32, and a third punch 33 arranged sequentially. The first punch 31 is I-shaped and mates with the receiving cavity 11. The second punch 32 is located between the upper spring sheet 21 and the lower spring sheet 22, both of which are located between the first punch 31 and the third punch 33. Figure 5 and Figure 7 As shown, the second punch 4 includes a connecting block 41, on which a fourth punch 42, a fifth punch 43, and a sixth punch 44 are sequentially arranged. The fourth punch 42 engages with the elastic space 23 between the upper spring sheet 21 and the needle body 1, and the sixth punch 44 engages with the elastic space 23 between the lower spring sheet 22 and the needle body 1. The fifth punch 43 is located between the upper spring sheet 21 and the lower spring sheet 22. In this embodiment, as... Figure 4 and Figure 5 As shown, an arc-shaped chamfer 34 is provided between the third punch block 33 and the second punch block 32, which facilitates the simultaneous formation of guide chamfers 24 on the outer sides of the upper spring sheet 21 and the lower spring sheet 22 facing the insertion direction of the drive circuit board 5 during the stamping of the first punch 3; the fifth punch block 43 has arc-shaped grooves 45 on both the top and bottom, which facilitates the simultaneous formation of arc surfaces where the working surfaces of the upper spring sheet 21 and the lower spring sheet 22 approach each other during the stamping of the second punch 4, as well as guide chamfers 24 on both sides of the upper spring sheet 21 and the lower spring sheet 22 facing the insertion direction of the drive circuit board 5 during the stamping of the second punch 4.

[0031] The working principle of this metal needle is as follows:

[0032] This metal pin is suitable for high-power intelligent power modules (generally with voltage levels above 650V and current levels above 25A); firstly, several of these metal pins are soldered onto the metal-clad ceramic substrate of the existing main circuit board, and then the drive circuit board 5 is inserted into the snap-fit ​​structure 2 along the chamfer 24, as shown. Figure 3 As shown, at this time, the drive circuit board 5 is located between the upper spring 21 and the lower spring 22, and the side of the drive circuit board 5 is located in the receiving cavity 11. Several metal pins are secured to the three adjacent sides of the drive circuit board 5 by the snap-fit ​​structure 2, ensuring that the drive circuit board 5 forms a drawer-shaped structure after being inserted into the snap-fit ​​structure 2, which facilitates the assembly of the drive circuit board 5 and ensures that its position is well restricted.

[0033] The working principle of this stamping die in producing the metal needle is as follows:

[0034] like Figure 6 and Figure 7As shown, the middle side edges of the needle body 1 are punched by puncher one 3 and puncher two 4 in turn, and the punching directions of puncher two 4 and puncher one 3 are perpendicular to each other, wherein the first punch block 31 is matched with the accommodating cavity 11, the second punch block 32 is located between the upper spring plate 21 and the lower spring plate 22, the upper spring plate 21 and the lower spring plate 22 are both located between the first punch block 31 and the third punch block 33, the fourth punch block 42 is matched with the elastic space 23 between the upper spring plate 21 and the needle body 1, the sixth punch block 44 is matched with the elastic space 23 between the lower spring plate 22 and the needle body 1, and the fifth punch block 43 is located between the upper spring plate 21 and the lower spring plate 22.

[0035] The above merely describes the preferred embodiments of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can make equivalent replacements or changes according to the technical scheme and the inventive concept of the present application within the technical range disclosed by the present application, and all of them should be covered within the protection scope of the present application.

Claims

1. A metal pin for connecting a drive circuit board, characterized by: The device includes a needle body (1) and a snap-fit ​​structure (2). The snap-fit ​​structure (2) includes an upper spring piece (21) and a lower spring piece (22). A receiving cavity (11) is provided on the middle side of the needle body (1). The upper spring piece (21) and the lower spring piece (22) are disposed in the receiving cavity (11). There is an elastic space (23) between the upper spring piece (21) and the needle body (1), and there is also an elastic space (23) between the lower spring piece (22) and the needle body (1). The distance between the upper spring piece (21) and the lower spring piece (22) is less than the thickness of the drive circuit board (5). The side of the drive circuit board (5) is located in the receiving cavity (11). Several metal needles are snapped onto three adjacent sides of the drive circuit board (5) by the snap-fit ​​structure (2). The snap-fit ​​structure (2) is formed by stamping with a stamping die. The stamping die includes a first stamp (3) and a second stamp (4). The first stamp (3) includes a first punch (31), a second punch (32), and a third punch (33) arranged sequentially. The first punch (31) is I-shaped and fits into the receiving cavity (11). The second punch (32) is located between the upper spring sheet (21) and the lower spring sheet (22). The upper spring sheet (21) and the lower spring sheet (22) are both located between the first punch (31) and the lower spring sheet (22). Between the third punch block (33); the second punch (4) includes a connecting block (41), on which a fourth punch block (42), a fifth punch block (43) and a sixth punch block (44) are arranged in sequence. The fourth punch block (42) cooperates with the elastic space (23) between the upper spring sheet (21) and the needle body (1). The sixth punch block (44) cooperates with the elastic space (23) between the lower spring sheet (22) and the needle body (1). The fifth punch block (43) is located between the upper spring sheet (21) and the lower spring sheet (22).

2. The metal pin connecting the drive circuit board according to claim 1, characterized by: The working surfaces of the upper spring (21) and the lower spring (22) are arc surfaces that are close to each other.

3. The metal pin connecting the drive circuit board according to claim 2, characterized by: Both the upper spring (21) and the lower spring (22) have an inlet chamfer (24) in the insertion direction toward the drive circuit board (5).

4. The metal pin for connecting a drive circuit board according to any one of claims 1 to 3, characterized by: The metal needle is made of copper or a copper alloy.

5. The metal pin connecting drive circuit boards according to claim 1, wherein: An arc-shaped chamfer (34) is provided between the third punch (33) and the second punch (32); an arc-shaped groove (45) is provided on both the top and bottom of the fifth punch (43).

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