Flexible circuit board with sampling branch structure and manufacturing method

Abstract

The invention discloses a flexible circuit board with sampling branch structures and a manufacturing method. The flexible circuit board with the sampling branch structures comprises a flexible circuit board 1, a plurality of branch structures 2 arranged on the 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 method has the beneficial effects that the low cost of backing material straight welding FPC and the low process cost and stability of FPC laser welding are integrated, the working time and efficiency are better, and the whole working procedure is shortened.

Description

Technical Field

[0001] The present invention relates to the field of electronic technology, and in particular to a flexible circuit board with a sampling branch structure and a manufacturing method thereof. Background Art

[0002] New energy vehicles are rapidly developing, and power batteries are essential for their use. The safety of power batteries is a critical issue. Currently, the sampling branch connecting the battery pack to the power battery requires separate processing and then soldering to a flexible printed circuit (FPC). The FPC is soldered to the battery pack using a direct soldering process. However, the applicant has identified significant deficiencies in the existing technology: 1. It requires a production line for the sampling branch and another line for soldering the sampling branch, resulting in high production costs. 2. The FPC direct soldering process currently suffers from high production line construction costs, a lengthy process flow, and poor overall process stability. This makes online automated visual inspection (AVI) prone to false positives, a significant industry challenge.

[0003] Therefore, there is an urgent need to develop a flexible circuit board with a sampling branch structure and a manufacturing method that is easy to produce, has high production stability and low cost. Summary of the Invention

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

[0005] To this end, a first object of the present invention is to provide a flexible circuit board with a sampling branch structure, which is easy to produce, has high production stability and low cost.

[0006] The second object of the present invention is to provide a method for producing a flexible circuit board with a sampling branch structure.

[0007] To achieve the above-mentioned objectives, an embodiment of the present invention discloses a flexible circuit board with a sampling branch structure, comprising a flexible circuit board 1, a plurality of branch structures 2 arranged on both sides of the flexible circuit board 1, and a hollow portion 3 arranged 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, and 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 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.

[0008] In addition, the flexible circuit board with a sampling branch structure according to the above technical solution of the present application may also have the following additional technical features: Optionally, a micro-connection portion 4 is provided at the end of the branch structure 2 , and the branch structure 2 is connected to the flexible circuit board 1 via the micro-connection portion 4 .

[0009] Optionally, a plurality of inwardly recessed buffer arms 24 are provided at the root of the branch structure 2 .

[0010] Optionally, the electrical connection portion 212 is a solder paste layer; and the metal sheet 23 is a steel sheet or a nickel sheet.

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

[0012] To achieve the above-mentioned purpose, the second embodiment of the present invention proposes a method for manufacturing a flexible circuit board with a sampling branch structure, comprising the following steps: S010: a sampling branch is formed in the flexible circuit board through a cutting process, wherein the cut portion of the flexible circuit board is a hollow portion; S020: the sampling branch is opened on one side in the film to form a window portion and expose the internal conductor; S030: a layer of conductive paste or slurry is applied to the window portion to form an electrical connection portion; S040: the conductor in the window portion is connected to a metal sheet through the electrical connection portion; thereby, a flexible circuit board with a sampling branch structure as described in claim 1 is manufactured.

[0013] Optionally, step S010 further includes step S011: when cutting the flexible circuit board, a section is retained between the flexible circuit board and the end of the sampling branch, and the adhesion section is a micro-connection portion; thereby, a flexible circuit board with a sampling branch structure as described in claim 2 is manufactured.

[0014] Optionally, it is characterized in that: in step S010, it also includes step S012: when cutting the flexible circuit board, a plurality of inward depressions are formed at the root position of the branch structure, and the position of the depression is the buffer arm; thereby, a flexible circuit board with a sampling branch structure as described in claim 3 is produced.

[0015] Optionally, step S030 is step S031: applying a layer of solder paste on the window portion to form a solder paste layer electrical connection portion; the metal sheet in step S040 is a steel sheet or a nickel sheet; thereby producing a flexible circuit board with a sampling branch structure as described in claim 4.

[0016] Optionally, step S030 is step S032: applying a layer of conductive silver paste on the window portion to form a silver paste layer electrical connection portion; the metal sheet in step S040 is a steel sheet or a nickel sheet; thereby producing a flexible circuit board with a sampling branch structure as described in claim 5.

[0017] The beneficial effects of the present invention are: combining the low cost of direct soldering of FPC with base material and the low process cost and stability of FPC laser welding, the working time efficiency will be better, and the overall process will be shortened. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a structural diagram of a flexible circuit board with a sampling branch structure provided by an embodiment of the present application; Figure 2 This is a partial diagram of a sampling branch of a flexible circuit board with a sampling branch structure provided by an embodiment of the present application; Figure 3 This is a schematic AA cross-sectional view of the structure of a flexible circuit board with a sampling branch structure provided by another embodiment of the present application; Figure 4 This is a flow chart of a method for manufacturing a flexible circuit board with a sampling branch structure provided by one embodiment of the present application; Figure 5 This is a flow chart of a method for manufacturing a flexible circuit board with a sampling branch structure provided by another embodiment of the present application; Figure 6 This is a flow chart of a method for manufacturing a flexible circuit board with a sampling branch structure provided by another embodiment of the present application; Figure 7 This is a flow chart of a method for manufacturing a flexible circuit board with a sampling branch structure provided in another embodiment of the present application.

[0019] Reference numerals: 1-flexible circuit board, 2-branch structure, 21-welding area, 211-window portion, 22-conductor, 212-electrical connection portion, 23-metal sheet, 24-buffer arm, 3-hollow portion, 4-micro connection portion. DETAILED DESCRIPTION

[0020] Embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or components / elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

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

[0022] Figure 1 FIG. 1 is a structural diagram of a flexible circuit board with a sampling branch structure provided by an embodiment of the present application. Figure 1As shown: The flexible circuit board with a sampling branch structure includes a flexible circuit board 1, a plurality of branch structures 2 arranged on both sides of the flexible circuit board 1, and a hollow portion 3 arranged between the flexible circuit board 1 and the branch structure 2; wherein, the root of the branch structure 2 is connected to the flexible circuit board 1, the top is a welding area 21, and a window portion 211 is provided in the middle of one side of the welding area 21, the inside of the window portion 211 is a conductor 22, and the outside 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 an embodiment of the present application, the electrical connection portion 212 is a solder paste layer; and the metal sheet 23 is a steel sheet or a nickel sheet. Embodiment 1:

[0024] In this embodiment, a sampling branch 2 is formed by cutting the flexible printed circuit board (FPC). A window 211 is then opened on one side of the FPC film, exposing an internal conductor 22. For FPCs, this is typically copper foil. Solder paste is then applied to the window 211 to form an electrical connection 212. A metal sheet 23, such as stainless steel or nickel, is then attached using surface mounting technology (SMT).

[0025] It should be noted that the welding area reinforced with steel or nickel sheets in this application can be laser welded. Therefore, in addition to the strength of the welding area itself being strengthened, the overall strength after welding is also significantly enhanced. Compared with the FPC direct welding process in the prior art, this solution reduces the FPC width and uses a smaller metal sheet as the welding intermediate medium. The metal sheet can be directly welded to the aluminum bar through the laser welding process. The laser welding process is more mature than the ultrasonic welding process in the industry, and the quality of the finished product is more stable, which makes the entire process stable, the welding strength is high, avoids AVI detection false alarms, has a high yield rate, and high production efficiency, solving a series of industry problems.

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

[0027] According to the flexible circuit board with a sampling branch structure of the present application, the sampling branch is directly processed into the flexible circuit board without the need for additional welding, and the sampling branch serves as an intermediate medium for welding the aluminum bar in the battery pack by connecting the metal sheet. The sampling branch also has a certain rigidity to avoid deformation of the product and can be directly welded using a mature laser welding process, thereby shortening and simplifying the product production process, reducing production costs, and improving product strength and yield.

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

[0029] In this embodiment: a sampling branch 2 is made in a flexible printed circuit board through a cutting process, and then a window is opened on one side of the film of the sampling branch to form a window portion 211 and expose the internal conductor 22. Then, a conductive silver paste is applied on the window portion 211 to form an electrical connection portion 212 of the conductive paste layer, and 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 welding areas reinforced with steel sheets or nickel sheets in this application can be welded by laser welding. This solution combines the process stability and yield advantages of FPC metal sheets (such as nickel sheets and steel sheets) through laser CCS as well as the welding strength, while avoiding the problems of poor stability of FPC direct welding and false positives in AVI visual inspection, 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 the present application, a micro-connection portion 4 is provided at the end of the branch structure 2 , 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 avoid the welding point from breaking and causing system failure, a micro-connection 4 can be set at the branch structure 2 to connect the flexible circuit board 1. This micro-connection 4 will be disconnected first when subjected to a large external force, thereby protecting the welding point.

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

[0034] Specifically, the buffer arm 24 extends the stretching length of the branch structure 2, and does not directly extend the branch structure 2. Therefore, when the welding point is excessively stretched, 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 embodiment, the present invention further proposes a method for manufacturing a flexible circuit board with a sampling branch structure. Figure 4 FIG. 1 is a flow chart of a method for manufacturing a flexible circuit board with a sampling branch structure provided by an embodiment of the present application. Figure 4 As shown, the method comprises the following steps: S010: forming a sampling branch in a flexible circuit board through a cutting process, wherein the cut portion of the flexible circuit board is a hollow portion; S020: opening a window on one side of the film of the sampling branch to form a window portion and expose the internal conductor; S030: applying a layer of conductive paste or slurry on the window portion to form an electrical connection portion; S040: connecting the conductor in the window portion to a metal sheet through the electrical connection portion; thereby forming a flexible circuit board with a sampling branch structure as described in claim 1.

[0036] Figure 5 This is a flow chart of a method for manufacturing a flexible circuit board with a sampling branch structure provided by another embodiment of the present application. Figure 5 As shown, at step S010, step S011 is also included: when cutting the flexible circuit board, a section is retained between the flexible circuit board and the end of the sampling branch, and the adhesion section is a micro-connection portion; thereby, a flexible circuit board with a sampling branch structure as described in claim 2 is manufactured.

[0037] According to one embodiment of the present application, step S010 further includes step S012: when cutting the flexible circuit board, a plurality of inward depressions are formed at the root position of the branch structure, and the positions of the depressions serve as buffer arms; thereby producing a flexible circuit board with a sampling branch structure as described in claim 3.

[0038] Figure 6 This is a flow chart of a method for manufacturing a flexible circuit board with a sampling branch structure provided by another embodiment of the present application. Figure 6 As shown, step S030 is step S031: applying a layer of solder paste on the window portion to form a solder paste layer electrical connection portion; the metal sheet at step S040 is a steel sheet or a nickel sheet; thereby making a flexible circuit board with a sampling branch structure as described in claim 4.

[0039] It should be noted that when the solder paste layer is used as the electrical connection part, the SMT process can be used for patching, the steel sheet or nickel sheet can be electrically connected to the conductor and bonded to the sampling branch.

[0040] Figure 7 This is a flow chart of a method for manufacturing a flexible circuit board with a sampling branch structure provided by another embodiment of the present application. Figure 7As shown, step S030 is step S032: a layer of conductive silver paste is applied to the window portion to form a silver paste layer electrical connection portion; the metal sheet at step S040 is a steel sheet or a nickel sheet; thereby, a flexible circuit board with a sampling branch structure as described in claim 5 is manufactured.

[0041] It should be noted that in the solution of using conductive silver paste for connection, the patch operation can be performed using a dispensing coating process, a spraying process or a die bonding process, or the SMT process can be used for patch operation.

[0042] According to a manufacturing method of a flexible circuit board with a sampling branch structure of the present invention, a sampling branch is directly processed in the flexible circuit board without the need for additional welding, and the sampling branch serves as an intermediate medium for welding the aluminum bar in the battery pack by connecting the metal sheet. The sampling branch has a certain rigidity to avoid deformation of the product and can be directly welded using a mature laser welding process, thereby shortening and simplifying the product production process, reducing production costs, and improving the strength and yield rate of the product.

[0043] The above embodiments are preferred implementation schemes of the present invention. In addition, the present invention can also be implemented in other ways. Any obvious replacement without departing from the concept of the present invention is within the scope of protection of the present invention.

Claims

1. A flexible circuit board with a sampling branch structure, characterized in that: include: A flexible circuit board (1), a plurality of branch structures (2) arranged on both sides of the flexible circuit board (1), and a hollow portion (3) arranged 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 portion (211) is provided in the middle of one side of the welding area (21). The inside of the window portion (211) is a conductor (22). An electrical connection portion (212) is provided on the outside of the window portion (211), and the electrical connection portion (212) is connected to a metal sheet (23).

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

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

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

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

6. A method for manufacturing a flexible circuit board with a sampling branch structure, characterized in that: The following steps are involved: S010: forming a sampling branch in the flexible circuit board through a cutting process, wherein the cut portion of the flexible circuit board is a hollow portion; S020: The sampling branch is opened on one side of the membrane to form a window portion and expose the internal conductor; S030: Apply a layer of conductive paste or slurry on the window portion to form an electrical connection portion; S040: Connecting the conductor in the window portion to a metal sheet through an electrical connection portion; Thus, a flexible circuit board with a sampling branch structure as claimed in claim 1 is manufactured.

7. The method for manufacturing a flexible circuit board with a sampling branch structure according to claim 6, characterized in that: In step S010, the method further includes step S011: when cutting the flexible circuit board, leaving a section between the flexible circuit board and the end of the sampling branch bonded together, the bonded section being a micro-connection; Thus, a flexible circuit board with a sampling branch structure as claimed in claim 2 is manufactured.

8. The method for manufacturing a flexible circuit board with a sampling branch structure according to claim 6, characterized in that: In step S010, the method further includes step S012: when cutting the flexible circuit board, forming a plurality of inward depressions at the root of the branch structure, where the depressions serve as buffer arms; Thus, a flexible circuit board with a sampling branch structure as described in claim 3 is manufactured.

9. The method for manufacturing a flexible circuit board with a sampling branch structure according to claim 6, characterized in that: Step S030 is step S031: applying a layer of solder paste on the window portion to form a solder paste layer electrical connection portion; The metal sheet in step S040 is a steel sheet or a nickel sheet; Thus, a flexible circuit board with a sampling branch structure as claimed in claim 4 is manufactured.

10. The method for manufacturing a flexible circuit board with a sampling branch structure according to claim 6, characterized in that: Step S030 is step S032: applying a layer of conductive silver paste on the window portion to form a silver paste layer electrical connection portion; The metal sheet in step S040 is a steel sheet or a nickel sheet; Thus, a flexible circuit board with a sampling branch structure as described in claim 5 is manufactured.

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