US-12620635-B2 - Printed circuit board, battery module, battery pack, and electrical device

Abstract

This application discloses a printed circuit board, a battery module, a battery pack, and an electrical device. The printed circuit board may include: a substrate, a pad, a solder paste layer, a component body, and a support assembly. The pad may be disposed above the substrate. The solder paste layer may be disposed above the pad. The component body may be disposed above the solder paste layer. The support assembly may be disposed between the pad and the component body to form a degassing space between the component body and the solder paste layer.

Inventors

• Xin Li
• Zhaohang SHI

Assignees

• CONTEMPORARY AMPEREX TECHNOLOGY (HONG KONG) LIMITED

Dates

Publication Date

20260505

Application Date

20220915

Priority Date

20211229

Claims (13)

1. 1 . A printed circuit board, comprising: a substrate; a pad above the substrate; a solder paste layer above the pad; a component body above the solder paste layer; and a support assembly between the pad and the component body to form a degassing space between the component body and the solder paste layer, wherein one end of the support assembly is connected to the component body, and another end of the support assembly extends into the solder paste layer to directly connect to the pad, the support assembly is soldering lug, which has a higher melting point than solder paste in the solder paste layer, the printed circuit board further comprises a fixing assembly for preventing an offset in a case of connecting the component body to the pad between the component body and the pad, the fixing assembly comprises a solder paste zone and a limiting post, the solder paste zone is disposed on the pad, one end of the limiting post is connected to the component body, and another end of the limiting post is connected to the solder paste zone, the limiting post is disposed at a flank of the component body, and a thickness of the solder paste zone is greater than a thickness of the solder paste layer.
2. 2 . The printed circuit board according to claim 1 , wherein the support assembly comprises at least two pillars.
3. 3 . The printed circuit board according to claim 2 , wherein the pillars are tin slugs.
4. 4 . The printed circuit board according to claim 2 , wherein the solder paste layer comprises solder paste which is composed of a mixture of tin solder powders, a flux, a surfactant, and a thixotropic agent.
5. 5 . The printed circuit board according to claim 2 , wherein a height of each of the at least two pillars is greater than a thickness of the solder paste layer.
6. 6 . The printed circuit board according to claim 1 , wherein the support assembly is axially symmetrically arranged along a vertical centerline of the component body.
7. 7 . The printed circuit board according to claim 1 , wherein the limiting post is a pin, and the pin is an inherent component pin of the component body.
8. 8 . The printed circuit board according to claim 1 , wherein the fixing assembly comprises at least two pins as limiting posts.
9. 9 . The printed circuit board according to claim 1 , wherein the limiting post is in an inverted L shape.
10. 10 . A battery module, wherein the battery module comprises the printed circuit board according to claim 1 , and the printed circuit board is located in the battery module.
11. 11 . A battery pack, wherein the battery pack comprises the battery module according to claim 10 .
12. 12 . An electrical device, wherein the electrical device comprises the battery pack according to claim 11 , and the battery pack is configured to provide electrical energy.
13. 13 . A battery module, wherein the battery module comprises the printed circuit board according to claim 1 , and the printed circuit board is located in the battery module.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS The present application is a continuation of International Application No. PCT/CN2022/088389, filed Apr. 22, 2022, which claims priority to Chinese Patent Application No. 202123382798.5, filed on Dec. 29, 2021 and entitled “PRINTED CIRCUIT BOARD, BATTERY MODULE, BATTERY PACK, AND ELECTRICAL DEVICE”, each of which is incorporated herein by reference in its entirety. TECHNICAL FIELD This application relates to the technical field of batteries, and in particular, to a printed circuit board, a battery module, a battery pack, and an electrical device. BACKGROUND Energy conservation and emission reduction is key to sustainable development of the automobile industry. Electric vehicles have become an important part of the sustainable development of the automobile industry by virtue of energy saving and environmental friendliness. Battery technology is crucial to development of the electric vehicles. A printed circuit board is a circuit board commonly used in a battery module. Commonly used electronic parts need to be welded onto a pad of a substrate of the PCB (Printed Circuit Board, printed circuit board). However, the welding effect is affected by many factors, and the welding effect of finished electronic parts is usually inferior and tends to affect normal use of the PCB. SUMMARY In view of the problems above, this application provides a printed circuit board, a battery module, a battery pack, and an electrical device to reduce a void rate at the bottom of a component body by 30% to 40% and reduce an offset of the component body (MOS transistor) in the related art. According to a first aspect, this application provides a printed circuit board, including: a substrate, a pad, a solder paste layer, a component body, and a support assembly. The pad is disposed above the substrate. The solder paste layer is disposed above the pad. The component body is disposed above the solder paste layer. The support assembly is disposed between the pad and the component body to form a degassing space between the component body and the solder paste layer. In the technical solutions of embodiments of this application, soldering lugs are placed symmetrically at the bottom of the electronic part to steadily hold the electronic part and form an off-contact structure as a gas escape space at the bottom of the electronic part. By using a difference of melting points between the solder paste and the soldering lugs, gas generated by the solder paste during melting can be evacuated through the off-contact structure, thereby preventing the gas from forming a void at the position of the solder paste. The soldering lugs begin to melt only after the solder paste has melted, thereby reasonably ensuring that most of the gas can be volatilized in all directions. At a flank of the electronic part, the position of the electronic part is limited by a position limiter. By changing the thickness of the solder paste at the bottom of the position limiter, the position limiter is enabled to implement position limitation, thereby preventing an offset of the electronic part during melting and welding. In some embodiments, one end of the support assembly is connected to the component body, and the other end of the support assembly extends into the solder paste layer to connect to the pad. By melting the solder paste layer and the support assembly in a soldering oven at a high temperature, the component body and the limiting post thereof are efficiently fixed to the pad on the substrate. In some embodiments, the support assembly includes at least two pillars. This facilitates supporting of the component body. In addition, the support assembly facilitates lifting of the component body, and helps to ensure the volatilization of gas and a relatively high welding speed. In some embodiments, the support assembly is axially symmetrically arranged along a vertical centerline of the component body. The axially symmetrically arranged support assembly ensures that balanced supporting of the component body, and minimizes a horizontal offset in a process of melting the support assembly and lowering the component body. In some embodiments, the pillars are tin slugs. A melting point of the tin slugs is higher than a melting point of the solder paste, effectively ensuring the effect of the degassing space. In some embodiments, a melting point of the support assembly is greater than or equal to a melting point of the solder paste layer. This effectively ensures that the solder paste layer is melted before the support assembly. In this way, time is enough for exhausting the gas from the degassing space before the process of melting the support assembly. In some embodiments, a height of a pillar is greater than a thickness of the solder paste layer, thereby effectively ensuring that the pillar can lift the component body to form the degassing space. In some embodiments, a fixing assembly for preventing an offset in a case of connecting