Flexible circuit board with sampling branch structure and battery pack

Abstract

The utility model discloses a flexible circuit board with sampling branch structures and a battery pack. The flexible circuit board with the sampling branch structures comprises a flexible circuit board 1, a plurality of branch structures 2 arranged on two sides of the flexible circuit board 1, and hollow parts 3 arranged between the flexible circuit board 1 and the branch structures 2, wherein the root part of the branch structure 2 is connected with the flexible circuit board 1, the top part of the branch structure 2 is a welding area 21, the middle part of one surface of the welding area 21 is provided with a windowing part 211, the inner side of the windowing part 211 is provided with a conductor 22, the outer side of the windowing part 211 is provided with an electric connection part 212, and the electric connection part 212 is connected with a metal sheet 23. The beneficial effects of the utility model lie in that low cost of a backing material straight welding FPC and low process cost and stability of FPC laser welding are integrated, working hours and efficiency are better, and the whole process is also shortened.

Description

Technical Field

[0001] This utility model relates to the field of electronic technology, specifically to a flexible circuit board and battery pack with a sampling branch structure. Background Technology

[0002] With the rapid development of new energy vehicles, power batteries are essential components, and their safety remains a critical issue. Currently, the sampling branches connecting to the battery pack in power batteries need to be individually fabricated and then soldered onto a flexible printed circuit (FPC). FPC soldering to the battery pack is achieved through a direct soldering process. However, the applicant has identified serious shortcomings in existing technologies: 1. A separate production line is required to manufacture the sampling branches, and another line is needed to solder them, resulting in high production costs; 2. The current FPC direct soldering process has high production line setup costs, a long process flow, poor overall process stability, and is prone to false alarms during online automated visual inspection (AVI), a persistent industry challenge.

[0003] Therefore, there is an urgent need to develop a flexible circuit board and battery pack with a sampling branch structure that is easy to manufacture, has high production stability, and low cost. Utility Model Content

[0004] The present invention aims to solve the above-mentioned technical problems.

[0005] Therefore, the first objective of this utility model is to propose a flexible circuit board with a sampling branch structure that is easy to manufacture, has high production stability, and low cost.

[0006] The second objective of this invention is to provide a battery pack.

[0007] To achieve the above objectives, this utility model discloses a flexible circuit board with a sampling branch structure, comprising: a flexible circuit board 1, a plurality of branch structures 2 disposed on both sides of the flexible circuit board 1, and a cutout portion 3 disposed between the flexible circuit board 1 and the branch structures 2; wherein, the root of the branch structure 2 is connected to the flexible circuit board 1, the top is a welding area 21, a window portion 211 is provided in the middle of one side of the welding area 21, the inner side of the window portion 211 is a conductor 22, and an electrical connection portion 212 is provided on the outer side of the window portion 211, the electrical connection portion 212 is connected to a metal sheet 23.

[0008] In addition, the flexible circuit board with sampling branch structure according to the above-mentioned technical solution of this application may also have the following additional technical features:

[0009] Optionally, the end of the branch structure 2 is provided with a micro-connection 4, and the branch structure 2 is connected to the flexible circuit board 1 through the micro-connection 4.

[0010] Optionally, the root of the branch structure 2 is provided with a plurality of inwardly recessed buffer arms 24.

[0011] Optionally, the electrical connection 212 is a solder paste layer; the metal sheet 23 is a steel sheet or a nickel sheet.

[0012] Optionally, the electrical connection 212 is a conductive paste layer; the metal sheet 23 is a steel sheet or a nickel sheet.

[0013] To achieve the above objectives, a second aspect of the present invention provides a battery pack comprising: a flexible circuit board with a sampling branch structure as described in the first aspect of the present invention.

[0014] The advantages of this invention are: it combines the low cost of direct welding of FPC with the low process cost and stability of FPC laser welding, resulting in better working efficiency and a shorter overall process. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of a flexible circuit board with a sampling branch structure provided in one embodiment of this application;

[0016] Figure 2 This is a partial view of the sampling branch of a flexible circuit board with a sampling branch structure provided in one embodiment of this application;

[0017] Figure 3 This is a schematic cross-sectional view (AA) of a flexible circuit board with a sampling branch structure provided in another embodiment of this application.

[0018] Figure label:

[0019] 1-Flexible circuit board, 2-Branch structure, 21-Soldering area, 211-Window opening, 22-Conductor, 212-Electrical connection, 23-Metal sheet, 24-Buffer arm, 3-Koilout, 4-Micro connection. Detailed Implementation

[0020] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or components / elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0021] The following describes a flexible circuit board with a sampling branch structure according to an embodiment of the present invention, in conjunction with the accompanying drawings.

[0022] Figure 1 This is a schematic diagram of a flexible circuit board with a sampling branch structure provided in one embodiment of this application, as shown below. Figure 1 As shown: The flexible circuit board with sampling branch structure includes a flexible circuit board 1, several branch structures 2 disposed on both sides of the flexible circuit board 1, and a cutout portion 3 disposed between the flexible circuit board 1 and the branch structures 2; wherein, the root of the branch structure 2 is connected to the flexible circuit board 1, the top is a soldering area 21, the middle of one side of the soldering area 21 is provided with a window portion 211, the inner side of the window portion 211 is a conductor 22, the outer side of the window portion 211 is provided with an electrical connection portion 212, and the electrical connection portion 212 is connected to a metal sheet 23.

[0023] According to one embodiment of this application, the electrical connection 212 is a solder paste layer; the metal sheet 23 is a steel sheet or a nickel sheet. Example 1:

[0024] In this embodiment: Sampling branches 2 are formed in the flexible circuit board through a cutting process. Then, a window is opened on one side of the sampling branch in the film to form a window portion 211, exposing the internal conductor 22, which is usually copper foil for FPC. Then, solder paste is applied to the window portion 211 to form an electrical connection portion 212. Then, a metal sheet 23, which can be a stainless steel sheet or a nickel sheet, is mounted on it using surface mount technology (SMT).

[0025] It should be noted that the weld area reinforced with steel or nickel sheets in this application can be laser welded. Therefore, in addition to the enhanced strength of the weld area itself, the overall strength after welding is also significantly improved. Compared to the existing FPC direct welding process, this solution reduces the FPC width and uses a smaller metal sheet as the welding intermediate. The metal sheet can be directly welded to the aluminum bar using laser welding. Laser welding is a more mature process than ultrasonic welding in the industry, and the finished product quality is more stable. This results in a stable process, high welding strength, avoids false alarms in AVI detection, high yield, high production efficiency, and solves a series of industry problems.

[0026] It should be noted that the welding area 21 is located around the conductor 22, and the covering material can be polyimide (PI). The PI surface and the conductor 22 can be connected by an adhesive (ADH).

[0027] According to the flexible circuit board with sampling branch structure of this application, the sampling branch is directly processed in the flexible circuit board without additional welding. The sampling branch is connected to the metal sheet as an intermediate medium for welding the aluminum bar in the battery pack. Moreover, the sampling branch has a certain rigidity to prevent product deformation. It can be directly welded using mature laser welding technology, thereby shortening and simplifying the product manufacturing process, reducing production costs, and improving product strength and yield.

[0028] According to one embodiment of this application, the electrical connection 212 is a conductive paste layer; the metal sheet 23 is a steel sheet or a nickel sheet. Example 2:

[0029] In this embodiment: Sampling branch 2 is made in the flexible circuit board by cutting process. Then, the sampling branch has a window on one side in the film to form a window 211 and expose the internal conductor 22. Then, conductive silver paste is applied to the window 211 to form the electrical connection part 212 of the conductive paste layer. Then, a metal sheet 23 is attached, which can be a stainless steel sheet or a nickel sheet.

[0030] It should be noted that the weld area reinforced with steel or nickel sheets in this application can be laser welded. This solution combines the advantages of process stability and yield of FPC metal sheets (such as nickel or steel sheets) through laser CCS with welding strength, while avoiding the problems of poor stability and false alarms in AVI visual inspection of FPC direct welding, low production efficiency, easy oxidation of FPC direct welding pads requiring vacuum packaging, and low welding strength requiring glue reinforcement.

[0031] According to one embodiment of this application, the end of the branch structure 2 is provided with a micro-connection portion 4, and the branch structure 2 is connected to the flexible circuit board 1 through the micro-connection portion 4.

[0032] Specifically, when the battery pack is subjected to a large external force, in order to prevent the welding point from breaking and causing the system to fail, a micro-connection 4 can be set at the branch structure 2 to connect the flexible circuit board 1. This micro-connection 4 will break first when subjected to a large external force, thereby protecting the welding point.

[0033] According to one embodiment of this application, the root of the branch structure 2 is provided with a plurality of inwardly recessed buffer arms 24.

[0034] Specifically, the buffer arm 24 extends the stretching length of the branch structure 2, but does not directly extend the branch structure 2. Thus, when the welding point is overstretched, the buffer arm 24 can be stretched first to prevent the flexible circuit board 1, the branch structure 2, or the welding point from being pulled, thereby protecting the flexible circuit board 1, the branch structure 2, and the welding point.

[0035] Based on the above embodiments, this utility model also proposes a battery pack, including: a flexible circuit board with a sampling branch structure as described in the above embodiments.

[0036] According to the present invention, a battery pack includes a flexible circuit board with a sampling branch structure. The sampling branch is directly processed in the flexible circuit board without additional welding. The sampling branch is connected to a metal sheet as an intermediate medium for welding the aluminum bar in the battery pack. The sampling branch has a certain rigidity to prevent product deformation. It can be directly welded using mature laser welding technology, thereby shortening and simplifying the product manufacturing process, reducing production costs, and improving product strength and yield.

[0037] The above embodiments are preferred implementations of this utility model. In addition, this utility model can also be implemented in other ways. Any obvious substitutions without departing from the concept of this utility model are within the protection scope of this utility model.

Claims

1. A flexible circuit board with a sampling branch structure, characterized in that, include: Flexible circuit board (1), several branch structures (2) disposed on both sides of the flexible circuit board (1), and a cutout portion (3) disposed between the flexible circuit board (1) and the branch structures (2). The root of the branch structure (2) is connected to the flexible circuit board (1), and the top is a welding area (21). A window (211) is provided in the middle of one side of the welding area (21). The inner side of the window (211) is a conductor (22), and an electrical connection (212) is provided on the outer side of the window (211). The electrical connection (212) is connected to a metal sheet (23).

2. The flexible circuit board with sampling branch structure according to claim 1, characterized in that: The branch structure (2) is provided with a micro-connection (4) at its end, and the branch structure (2) is connected to the flexible circuit board (1) through the micro-connection (4).

3. The flexible circuit board with sampling branch structure according to claim 1, characterized in that: The root of the branch structure (2) is provided with several inwardly recessed buffer arms (24).

4. A flexible circuit board with a sampling branch structure according to claim 1, characterized in that: The electrical connection part (212) is a solder paste layer; the metal sheet (23) is a steel sheet or a nickel sheet.

5. A flexible circuit board with a sampling branch structure according to claim 1, characterized in that: The electrical connection part (212) is a conductive paste layer; the metal sheet (23) is a steel sheet or a nickel sheet.

6. A battery pack, characterized in that: Including a flexible circuit board with a sampling branch structure as described in any one of claims 1-5.

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