Tin-welding-free power terminal and power module

Abstract

The invention provides a tin-welding-free power terminal, which relates to the technical field of power electronics and comprises a tin-welding-free head and a tin-welding-free base which are connected through a middle connecting rod. The tin-soldering-free head is a connecting plug, and the tin-soldering-free base is made of pure copper materials. The power terminal has the beneficial effects that the tin-soldering-free head of the power terminal is designed to be the connecting plug, and the tin-soldering-free base is designed to be made of the pure copper material, so that the power terminal can be connected with a PCB (Printed Circuit Board) in a plugging manner through the connecting plug, and ultrasonic welding with a direct copper-clad ceramic substrate is realized through the tin-soldering-free base; the technical scheme that a traditional power module must adopt a tin welding terminal is thoroughly abandoned, and meanwhile, the design of the middle connecting rod solves the contradiction that the terminal and the direct copper-clad ceramic substrate need a pure copper material for ultrasonic welding, and the terminal and the PCB need a high-strength metal material for plugging. And therefore, the problem of weak soldering reliability of the existing power module is thoroughly solved.

Description

Technical Field

[0001] The invention relates to the technical field of power electronics, and in particular to a tin-free welding power terminal and a power module. Background Art

[0002] At present, power modules are increasingly used in new energy vehicles, rail transit, wind power, solar power generation and other fields. However, due to the complexity of the operating environment and high expectations for system stability, the reliability requirements for the circuits and structural connections of power modules are becoming more and more stringent.

[0003] Traditional power modules use tin soldering technology to connect components. However, with the continuous expansion of power module application areas, especially in high-intensity and high-temperature environments, the limitations of traditional tin soldering technology have become increasingly prominent. Although tin soldering is a mature connection technology, its reliability performance in high-temperature environments is weak and is easily affected by thermal cycles, mechanical stress and environmental factors, leading to solder joint fatigue, cracks and even failure. This reliability problem is particularly evident in high-demand applications such as new energy vehicles and rail transit. Therefore, it is urgent to improve the component connection method of power modules. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides a tin-free soldering power terminal, comprising a tin-free soldering head and a tin-free soldering base connected by a connecting rod in the middle; the tin-free soldering head is a plug connector, and the tin-free soldering base is made of pure copper material.

[0005] Preferably, the solder-free head is made of a copper alloy material having a hardness greater than 120 HV.

[0006] Preferably, the surface layer of the pure copper material is bare copper or electroplated with one or more metal materials such as gold, nickel, tin, etc.

[0007] Preferably, the connecting rod is plug-connected to the solder-free base, a mounting column is provided on the solder-free base, and a plug-in hole matching the shape of one end of the connecting rod is provided in the mounting column.

[0008] Preferably, the cross section of one end of the connecting rod connected to the solder-free base is circular or polygonal.

[0009] Preferably, the solder-free head comprises a head body, and arc-shaped ears protruding outward are provided on both sides of a middle portion of the head body.

[0010] Preferably, the head body is flat.

[0011] Preferably, the connecting rod is plug-connected to the solder-free head, and a plug-in hole matching the shape of the connecting rod is formed at one end of the solder-free head facing the solder-free bottom.

[0012] The present invention also provides a power module, comprising a PCB board and a direct copper-clad ceramic substrate, the tin-free soldering head of the above-mentioned tin-free soldering power terminal is plug-connected to the PCB board, and the tin-free soldering base is connected to the copper layer of the direct copper-clad ceramic substrate by ultrasonic welding.

[0013] The above technical solution has the following advantages or beneficial effects: by designing the solder-free head of the power terminal as a plug connector and the solder-free base to be made of pure copper material, the power terminal can be plug-connected to the PCB board through the plug connector, and ultrasonic welding with the direct copper-clad ceramic substrate can be achieved through the solder-free base, completely abandoning the technical solution that the traditional power module must use tin-welded terminals. At the same time, the design of the middle connecting rod solves the contradiction that the ultrasonic welding of the terminal and the direct copper-clad ceramic substrate requires pure copper material, while the connection with the PCB board requires high-strength metal material, thereby completely solving the problem of weak soldering reliability of the existing power module. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 and Figure 2 This is a schematic structural diagram of a tin-free welding power terminal in a preferred embodiment of the present invention; Figure 3 and Figure 4 This is a schematic diagram of the connection between the tin-free soldering power terminal and the PCB board and the direct copper-clad ceramic substrate in a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0015] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. The present invention is not limited to this embodiment, and other embodiments may also fall within the scope of the present invention as long as they conform to the gist of the present invention.

[0016] In a preferred embodiment of the present invention, based on the above problems existing in the prior art, a tin-free welding power terminal is provided. Figure 1 and Figure 2 As shown, it includes a solder-free head 2 and a solder-free base 3 connected by a connecting rod 1 in the middle; the solder-free head 2 is a plug connector, and the solder-free base 3 is made of pure copper material.

[0017] Specifically, in this embodiment, the specific shape and structure of the solder-free head 2 are not limited, as long as it can be inserted into the plug hole on the PCB board and tightly connected. In order to ensure reliable plug-in connection between the power terminal and the PCB board, in a preferred embodiment of the present invention, the solder-free head 2 is made of a copper alloy material with a hardness greater than 120HV.

[0018] More preferably, the solder-free head 2 comprises a head body 21 , and arc-shaped ears 22 protruding outward are provided on both sides of the middle portion of the head body 1 .

[0019] In a preferred embodiment of the present invention, the head body 21 is flat.

[0020] Specifically, in this embodiment, by designing the arc-shaped ear portion 22, the solder-free head 2 can be more conveniently inserted into the socket provided on the PCB board, and can be tightly clamped in the socket to achieve reliable connection.

[0021] In a preferred embodiment of the present invention, in order to adopt ultrasonic welding technology for the power terminal, based on the high-frequency and high-energy welding process of ultrasonic welding, the solder-free base 3 can only be made of pure copper material, wherein the surface layer of the pure copper material is bare copper or one or more of electroplated gold, nickel, tin and other metal materials.

[0022] In a preferred embodiment of the present invention, the connecting rod 1 is plug-connected with the solder-free base 3 , and a mounting column 31 is provided on the solder-free base 3 . A plug-in hole matching the shape of one end of the connecting rod 1 is provided in the mounting column 31 .

[0023] In a preferred embodiment of the present invention, the cross section of one end of the connecting rod 1 connected to the solder-free base 3 is circular or polygonal.

[0024] In a preferred embodiment of the present invention, the connecting rod 1 is plug-connected to the solder-free head 2 , and a plug-in hole matching the shape of the connecting rod 1 is formed at one end of the solder-free head 2 facing the solder-free bottom 3 .

[0025] Specifically, in the present embodiment, since the solder-free head 2 is made of copper alloy and the solder-free base 3 is made of pure copper, in order to realize the integration of components of two different materials, the two ends of the connecting rod 1 are respectively plugged into the solder-free base 3 and the solder-free head 2, so that the solder-free power terminal forms an integrated pin, which solves the contradiction between the pure copper required for ultrasonic welding of the power terminal and the direct copper-clad ceramic substrate DBC, and the high-strength copper alloy required for the power terminal and the PCB socket. Through technological innovation, the problem of weak soldering reliability in the use technology of the power terminal of the power module is completely solved.

[0026] The present invention also provides a power module, such as Figure 3 and Figure 4 As shown, it includes a PCB board 4 and a direct copper-clad ceramic substrate 5, the tin-free soldering head 2 of the above-mentioned tin-free soldering power terminal is plug-connected with the PCB board 4, and the tin-free soldering base 3 is connected to the copper layer of the direct copper-clad ceramic substrate 5 by ultrasonic welding.

[0027] The above description is only a preferred embodiment of the present invention, and does not limit the implementation mode and protection scope of the present invention. For those skilled in the art, it should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the contents of this specification and illustrations should be included in the protection scope of the present invention.

Claims

1. A tin-free soldering power terminal, characterized in that: It comprises a solder-free head and a solder-free base connected by a connecting rod in the middle; the solder-free head is a plug connector, and the solder-free base is made of pure copper material.

2. The tin-free soldering power terminal according to claim 1, characterized in that: The solder-free head is made of a copper alloy material with a hardness greater than 120 HV.

3. The tin-free soldering power terminal according to claim 1, characterized in that: The surface layer of the pure copper material may be bare copper or electroplated with one or more metal materials such as gold, nickel, tin, etc.

4. The tin-free soldering power terminal according to claim 1, characterized in that: The connecting rod is plug-connected with the solder-free base, a mounting column is provided on the solder-free base, and a plug-in hole matching the shape of one end of the connecting rod is provided in the mounting column.

5. The tin-free soldering power terminal according to claim 1, characterized in that: The cross section of one end of the connecting rod connected to the solder-free base is circular or polygonal.

6. The tin-free soldering power terminal according to claim 1, characterized in that: The solder-free head comprises a head body, and arc-shaped ears protruding outward are arranged on both sides of the middle part of the head body.

7. The tin-free soldering power terminal according to claim 6, characterized in that: The head body is flat.

8. The tin-free soldering power terminal according to claim 1, characterized in that: The connecting rod is plug-connected with the solder-free head, and a plug-in hole matching the shape of the connecting rod is formed at one end of the solder-free head facing the solder-free bottom.

9. A power module, characterized in that: It comprises a PCB board and a direct copper-clad ceramic substrate, wherein the tin-free soldering head of the tin-free soldering power terminal as described in any one of claims 1 to 8 is plug-connected to the PCB board, and the tin-free soldering base is connected to the copper layer of the direct copper-clad ceramic substrate by ultrasonic welding.

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