Flexible circuit board and integrated busbar

Abstract

The utility model discloses a flexible circuit board and an integrated busbar. The flexible circuit board comprises a base material layer, a circuit layer, a nickel sheet, a first protective layer and a second protective layer, the circuit layer is arranged on the surface of the base material layer, and the circuit layer is provided with a first bonding pad; the first protection layer covers the circuit layer, and a first windowing position is arranged at the position, matched with the first bonding pad, of the first protection layer; the nickel sheet is welded and connected with the first bonding pad through the first windowing position; the second protection layer covers the first protection layer and the nickel sheet, the second protection layer is provided with an epitaxial part, and the position of the epitaxial part is matched with the position of the nickel sheet and extends towards the outer side of the side line of the base material layer. After the nickel sheet is welded on the first bonding pad of the circuit layer, the second protection layer is processed on the basis of the first protection layer, and the extension part matched with the nickel sheet in position is arranged on the second protection layer, so that the binding force between the nickel sheet and the flexible circuit board can be improved, and the use reliability of the flexible circuit board can be improved.

Description

Technical Field

[0001] This utility model relates to the field of circuit board processing technology, and in particular to a flexible circuit board and integrated busbar. Background Technology

[0002] The integrated busbar, or CCS for short, is a signal acquisition component of the battery management system. It consists of a flexible circuit board and nickel strips soldered onto the board. The operating environment of the integrated busbar requires high shear force between the nickel strips and the flexible circuit board; during operation, the nickel strips are prone to peeling off from the flexible circuit board due to stress. Utility Model Content

[0003] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a flexible circuit board and an integrated busbar, which can improve the bonding force between the nickel sheet and the flexible circuit board.

[0004] On one hand, this utility model embodiment provides a flexible circuit board, including:

[0005] Substrate layer;

[0006] A circuit layer is disposed on the surface of the substrate layer, and the circuit layer is provided with a first pad.

[0007] A first protective layer covers the circuit layer, and the first protective layer is provided with a first opening at the position of the first pad;

[0008] The nickel sheet is soldered to the first pad through the first window opening;

[0009] A second protective layer covers the first protective layer and the nickel sheet. The second protective layer has an extension portion, the position of which is adapted to the position of the nickel sheet and extends outward from the edge of the substrate layer.

[0010] According to some embodiments of the present invention, the extension length of the outer portion is 2.0 ± 0.2 mm.

[0011] According to some embodiments of the present invention, the width of one side of the epitaxial portion is greater than the width of one side of the nickel sheet.

[0012] According to some embodiments of the present invention, the difference between the width of one side of the epitaxial portion and the width of one side of the nickel sheet is greater than or equal to 1.0 mm.

[0013] According to some embodiments of the present invention, the number of nickel sheets is multiple, and the number of epitaxial portions is equal to or less than the number of nickel sheets.

[0014] According to some embodiments of the present invention, the difference between the single-sided width of the first pad and the single-sided width of the nickel sheet is greater than or equal to 0.2 mm.

[0015] According to some embodiments of the present invention, the nickel sheet is provided with an exhaust groove.

[0016] According to some embodiments of the present invention, the width of the exhaust groove is 1.0±0.1mm, and the width of the exhaust groove is equal to half the width of the nickel sheet.

[0017] According to some embodiments of the present invention, the surface of the first pad is provided with a surface treatment protective layer.

[0018] On the other hand, this utility model embodiment provides an integrated busbar, including the aforementioned flexible circuit board.

[0019] The embodiments of this utility model have at least the following beneficial effects:

[0020] After the nickel sheet is soldered onto the first pad of the circuit layer, a second protective layer is processed on the basis of the first protective layer, and an extension portion adapted to the nickel sheet is provided on the second protective layer. This can improve the bonding force between the nickel sheet and the flexible circuit board, which is beneficial to improving the reliability of the flexible circuit board.

[0021] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0022] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0023] Figure 1 This is a schematic diagram of the stacked structure of the flexible circuit board according to an embodiment of the present utility model;

[0024] Figure 2 This is a top view of the flexible circuit board according to an embodiment of the present utility model.

[0025] Figure 3 for Figure 2 The center circle shows a magnified view of position A.

[0026] Figure label:

[0027] Substrate layer 100, circuit layer 200, first pad 210, first protective layer 300, nickel sheet 400, venting groove 410, second protective layer 500, epitaxial portion 510, third protective layer 600. Detailed Implementation

[0028] 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 elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0029] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0030] In the description of this utility model, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. If "first," "second," etc., are used in the description, they are only for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the sequential relationship of the indicated technical features.

[0031] In the description of this utility model, unless otherwise explicitly defined, the terms "setting", "installation", "connection", etc. should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in combination with the specific content of the technical solution.

[0032] This embodiment discloses an integrated busbar, including a flexible circuit board. Please refer to... Figure 1 The flexible circuit board includes a substrate layer 100, a circuit layer 200, a first protective layer 300, a nickel sheet 400, and a second protective layer 500. The circuit layer 200 is disposed on the surface of the substrate layer 100. Please refer to [reference needed]. Figure 2 and Figure 3The circuit layer 200 is provided with a first pad 210; a first protective layer 300 covers the circuit layer 200, and the first protective layer 300 is provided with a first window position adapted to the position of the first pad 210. The nickel sheet 400 is soldered to the first pad 210 through the first window position. The first window position is used to avoid obstructing the first pad 210, so as to facilitate the soldering of the nickel sheet 400 to the first pad 210. A second protective layer 500 covers the first protective layer 300 and the nickel sheet 400. The second protective layer 500 is provided with an extension portion 510, which is adapted to the position of the nickel sheet 400 and extends outward from the edge of the substrate layer 100. In addition, a third protective layer 600 is also provided on the other side of the substrate layer 100. The first protective layer 300, the second protective layer 500, and the third protective layer 600 are all made of PI film (polyimide film). The first protective layer 300, the second protective layer 500, and the third protective layer 600 are all connected to the previous layer by adhesive. For example, the first protective layer 300 is connected to the circuit layer 200 and the substrate layer 100 by adhesive, and the second protective layer 500 is connected to the first protective layer 300 and the nickel sheet 400 by adhesive.

[0033] After the nickel sheet 400 is soldered onto the first pad 210 of the circuit layer 200, a second protective layer 500 is processed on the basis of the first protective layer 300, and an extension portion 510 adapted to the nickel sheet 400 is provided on the second protective layer 500. This can improve the bonding force between the nickel sheet 400 and the flexible circuit board, which is beneficial to improving the reliability of the flexible circuit board.

[0034] The extension length of the epitaxial portion 510 is 2.0 ± 0.2 mm. For example, the extension length of the epitaxial portion 510 is 1.8 mm, 1.9 mm, 2.0 mm, 2.1 mm, or 2.2 mm. In conventional solutions, the nickel sheet 400 is soldered to the first pad 210. Due to poor soldering quality (such as cold solder joints or false solder joints), the nickel sheet 400 is easily peeled off from the first pad 210. Alternatively, the nickel sheet 400 is easily peeled off from the first pad 210 due to forces generated by the environment. In this embodiment, the second protective layer 500 is connected to the surface of the nickel sheet 400, which enhances the bonding force between the upper and lower surfaces of the nickel sheet 400, thereby increasing the difficulty of peeling off the nickel sheet 400. Furthermore, the epitaxial portion 510 of the second protective layer 500 extends outward from the edge of the substrate layer 100, which increases the coverage area of ​​the second protective layer 500 over the nickel sheet 400, effectively preventing the nickel sheet 400 from lifting upwards. In addition, the epitaxial portion 510 can also make the edge line of the second protective layer 500 and the edge line of the substrate layer 100 misaligned with each other. When the force generated by the usage environment is applied to the nickel sheet 400, it can prevent the stress of bending the nickel sheet 400 up and down from concentrating on the same straight line (for example, bending along the edge line of the substrate layer 100), effectively avoiding metal fatigue and improving the reliability of the nickel sheet 400.

[0035] The width of one side of the epitaxial portion 510 is greater than the width of one side of the nickel sheet 400. For example, the top view of the epitaxial portion 510 is rectangular. Assuming the centerline of the epitaxial portion 510 is collinear with the centerline of the nickel sheet 400, and the distance between the centerline of the epitaxial portion 510 and one side edge is L1, and the distance between the centerline of the nickel sheet 400 and one side edge of the nickel sheet 400 is L2, then L1 > L2. This allows the epitaxial portion 510 to cover the nickel sheet 400, increasing the difficulty of peeling off the nickel sheet 400. The difference between the width of one side of the epitaxial portion 510 and the width of one side of the nickel sheet 400 is greater than or equal to 1.0 mm. For example, if ΔL = L1 - L2, then ΔL ≥ 1.0 mm.

[0036] It is worth mentioning that there are multiple nickel sheets 400, and the number of epitaxial portions 510 is equal to or less than the number of nickel sheets 400. For example, there are 10 nickel sheets 400. Depending on the actual application requirements, for example, some positions (such as 3) of the nickel sheets 400 are prone to peeling, so it is necessary to improve the bonding strength. Epitaxial portions 510 can be provided at the corresponding positions, while the remaining positions (7) of the nickel sheets 400 are less prone to peeling and do not need to be provided with epitaxial portions 510.

[0037] Furthermore, to improve the bonding strength between the nickel sheet 400 and the first pad 210, the difference between the width of one side of the first pad 210 and the width of one side of the nickel sheet 400 is greater than or equal to 0.2 mm. This ensures that the first pad 210 has sufficient area to accommodate solder paste, thereby improving the soldering reliability between the nickel sheet 400 and the first pad 210. Additionally, please refer to... Figure 3 The nickel sheet 400 is provided with venting grooves 410, which allow solder paste to enter the upper surface of the nickel sheet 400 from the bottom through the venting grooves 410 during the soldering process, thereby enhancing the soldering reliability between the nickel sheet 400 and the first pad 210. Specifically, the width of the venting groove 410 is 1.0±0.1mm, which is equal to half the width of the nickel sheet 400. By reasonably setting the width of the venting groove 410, solder can enter the upper surface of the nickel sheet 400 from the bottom through the venting grooves 410, thereby strengthening the soldering strength of the nickel sheet 400. The surface of the first pad 210 is provided with a surface treatment protective layer, which can prevent oxidation of the surface of the first pad 210, thereby improving the soldering quality and enhancing the bonding force between the nickel sheet 400 and the first pad 210.

[0038] The embodiments of the present utility model have been described in detail above with reference to the accompanying drawings. However, the present utility model is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present utility model.

Claims

1. A flexible wiring board, characterized by, include: Substrate layer (100); A circuit layer (200) is disposed on the surface of the substrate layer (100), and the circuit layer (200) is provided with a first pad (210). A first protective layer (300) covers the circuit layer (200), and the first protective layer (300) is provided with a first opening at the position adapted to the first pad (210); The nickel sheet (400) is welded to the first pad (210) through the first window; A second protective layer (500) covers the first protective layer (300) and the nickel sheet (400). The second protective layer (500) is provided with an epitaxial portion (510), the position of which is adapted to the position of the nickel sheet (400) and extends outward from the edge of the substrate layer (100).

2. The flexible wiring board according to claim 1, characterized by The extension length of the extension portion (510) is 2.0 ± 0.2 mm.

3. The flexible wiring board according to claim 1, characterized by The width of one side of the epitaxial portion (510) is greater than the width of one side of the nickel sheet (400).

4. The flexible wiring board according to claim 3, characterized by The difference between the width of one side of the epitaxial portion (510) and the width of one side of the nickel sheet (400) is greater than or equal to 1.0 mm.

5. The flexible wiring board according to any one of claims 1 to 4, characterized by, The number of nickel sheets (400) is multiple, and the number of epitaxial portions (510) is equal to or less than the number of nickel sheets (400).

6. The flexible wiring board according to claim 1, wherein The difference between the width of one side of the first pad (210) and the width of one side of the nickel sheet (400) is greater than or equal to 0.2 mm.

7. The flexible wiring board according to claim 1 or 6, wherein The nickel sheet (400) is provided with an exhaust groove (410).

8. The flexible wiring board according to claim 7, characterized by The width of the venting groove (410) is 1.0±0.1mm, and the width of the venting groove (410) is equal to half the width of the nickel sheet (400).

9. The flexible wiring board according to claim 1, characterized by The surface of the first pad (210) is provided with a surface treatment protective layer.

10. An integrated busbar, characterized by, Including the flexible circuit board as described in any one of claims 1 to 9.

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