An FPC flexible circuit board

Abstract

The utility model discloses a kind of FPC flexible circuit board, including the board main body for accommodating fixed line, the board main body one side is equipped with pin end, the board main body with the pin end between is equipped with the bending part for protecting board piece.Bending part can reduce the bending stress of flat cable, can protect line when online flat cable bending, simultaneously avoid stress pulling and lead to anisotropic conductive adhesive film peeling failure, provide guarantee for the safe use and service life of product.

Description

[Technical Field]

[0001] This utility model relates to the field of printed circuit technology, and in particular to an FPC flexible circuit board. [Background Technology]

[0002] Flexible printed circuit boards (FPCs), using polyimide (PI) or polyester (PET) films as substrates, have become a key solution for the miniaturization and integration of modern electronic devices due to their high flexibility, thinness, and bendability. Compared to traditional rigid circuit boards, FPCs can be freely bent, rolled, or folded in three-dimensional space, significantly optimizing space utilization. They are particularly suitable for applications requiring dynamic deformation, such as smartphone hinges, wearable devices, and medical electronics.

[0003] However, under dynamic bending conditions, the outer copper foil of the FPC is prone to fatigue cracks due to tensile stress, while the inner copper foil suffers from substrate delamination due to compressive stress. This uneven stress distribution directly affects the anisotropic conductive film (ACF). When the peel force exceeds the adhesive layer's tolerance threshold, the bonding interface will rapidly crack and propagate, causing contact failure between conductive particles and the solder pads. Therefore, a flexible circuit board capable of reducing bending stress is needed. [Utility Model Content]

[0004] To solve the above-mentioned technical problems, this utility model proposes an FPC flexible circuit board.

[0005] This utility model is achieved by the following technical solution:

[0006] An FPC flexible circuit board includes a board body for accommodating fixed circuits, a pin terminal on one side of the board body, and a bending portion for protecting the board between the board body and the pin terminal.

[0007] The bending section can reduce the bending stress of the cable, protect the circuit when the cable is bent, and prevent the anisotropic conductive film from peeling off due to stress tension, thus ensuring the safe use and service life of the product.

[0008] As described above, the bending portion of the FPC flexible circuit board includes a single-layer area that has been softened and a composite area adjacent to the single-layer area for improving structural strength. The single-layer area and the composite area are located on the same side as the board body.

[0009] As described above, the FPC flexible circuit board has a coating layer covered with solder resist ink on the same side of the pin end corresponding to the bending part.

[0010] As described above, in the FPC flexible circuit board, the pin terminal is located on one side of the board body, and the pin terminal includes a first pin terminal and a second pin terminal, with a first electromagnetic film area provided between the first pin terminal and the second pin terminal.

[0011] As described above, the FPC flexible circuit board has an IC area for mounting circuits on the other side of the board body.

[0012] As described above, in the FPC flexible circuit board, a second electromagnetic film region is provided between the IC region and the single-layer region.

[0013] The FPC flexible circuit board described above uses polyimide or polyester material as its main body.

[0014] As described above, the FPC flexible circuit board has a window area on one side of the board body and multiple window holes on the other side of the board body to improve heat dissipation.

[0015] In the FPC flexible circuit board as described above, the window area is close to the IC area and the window area is far away from the bending portion.

[0016] The FPC flexible circuit board as described above includes an exposed copper area disposed on one side of the window area.

[0017] Compared with the prior art, the FPC flexible circuit board proposed in this utility model has the following beneficial effects:

[0018] 1. The bending section can reduce the bending stress of the cable, protect the line when the cable is bent, and prevent the anisotropic conductive film from peeling off due to stress tension, thus ensuring the safe use and service life of the product.

[0019] 2. By providing a softened single-layer region and a composite region adjacent to the single-layer region for improving structural strength at the bending portion, the single-layer region and the composite region can form a structure that is easy to bend. At the same time, the softened single-layer region can further optimize the stress at the bending portion and avoid stress tension causing the anisotropic conductive adhesive film to peel off and fail. [Attached Image Description]

[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0021] Figure 1 This is a schematic diagram of one perspective of the present invention;

[0022] Figure 2 This is a schematic diagram from another perspective of the present invention.

[0023] The corresponding reference numerals in the attached figures are as follows:

[0024] 1. Board body; 11. Pin terminal; 111. First pin terminal; 112. Second pin terminal; 12. Bending section; 121. Single-layer area; 122. Composite area; 13. First electromagnetic film area; 14. IC area; 15. Second electromagnetic film area; 16. Coating layer; 17. Window area; 18. Exposed copper area.

Detailed Implementation Methods

[0025] To make the technical problems solved, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0026] Specific embodiments, combined with Figures 1 to 2 As shown, the technical solution of this utility model is further illustrated. An FPC flexible circuit board includes a board body 1 for accommodating and fixing circuitry. A pin terminal 11 is provided on one side of the board body 1, and a bending portion 12 for protecting the board is provided between the board body 1 and the pin terminal 11. The bending portion 12 can reduce the bending stress of the wiring, protect the circuitry when the wiring is bent, and prevent stress pulling from causing the anisotropic conductive adhesive film to peel off and fail, thus ensuring the safe use and service life of the product.

[0027] In this embodiment, the pin terminal 11 is located on one side of the board body 1. The pin terminal 11 includes a first pin terminal 111 and a second pin terminal 112. A first electromagnetic film region 13 is provided between the first pin terminal 111 and the second pin terminal 112. The first electromagnetic film region 13 can prevent electromagnetic signals from interfering with the normal operation of electrical components and ensure the normal operation of the circuit board circuit.

[0028] Furthermore, as a preferred embodiment of this solution and not a limitation, the other side of the main board 1 is provided with an IC area 14 for mounting circuitry. Devices are mounted to the IC area 14 by adhesive bonding. This area, used for mounting integrated circuit chips, is responsible for core functions such as signal processing and control.

[0029] Furthermore, as a preferred embodiment of this solution and not a limitation, the bending portion 12 includes a softened single-layer region 121 and a composite region 122 adjacent to the single-layer region 121 for improving structural strength. The single-layer region 121 and the composite region 122 are located on the other side of the main body 1. Optionally, the thickness of the composite region 122 is greater than the thickness of the single-layer region 121. The single-layer region 121 and the composite region 122 can form a structure that is easy to bend. At the same time, the softening treatment of the single-layer region 121 can further optimize the stress at the bending portion 12 and avoid stress tension causing the anisotropic conductive adhesive film to peel off and fail.

[0030] Furthermore, as a preferred embodiment of this solution and not a limitation, a second electromagnetic film region 15 is provided between the IC region 14 and the single-layer region 121. The second electromagnetic film region 15 can prevent electromagnetic signals from interfering with the normal operation of electrical components and ensure the normal operation of the circuit board circuit.

[0031] Furthermore, as a preferred embodiment of this solution and not a limitation, a coating layer 16 covered with solder resist ink is provided on the board body 1 at the same side as the pin end 112 and corresponding to the position of the bent portion 12. The coating layer 16 can enhance the mechanical strength of the bent portion 12, provide additional protection, prevent the circuit from breaking due to stress, and improve the bending resistance and lifespan of the FPC flexible circuit board; in addition, the coating layer 16 can isolate the circuit from contact with air and moisture, prevent the circuit from oxidizing, and prevent short circuits between circuits caused by bending.

[0032] Furthermore, as a preferred embodiment of this solution and not a limitation, the main body 1 of the board is made of polyimide or polyester material. Polyimide material can provide structural support for the product and has high heat resistance, enabling it to withstand the high temperatures of welding; polyester material has good flexibility, which can protect the circuit board from bending.

[0033] Furthermore, as a preferred embodiment of this solution and not a limitation, the main board 1 has a window area 17 on one side. The window area 17 provides an exposed copper foil area for soldering, heat dissipation, or electrical connection, which can improve heat conduction efficiency and facilitate the rapid dissipation of heat generated by the devices in the IC area 14 during operation.

[0034] Furthermore, as a preferred embodiment of this solution and not a limitation, the window area 17 is close to the IC area 14 and far away from the bend 12. The window area 17 provides a solderable area for the pins or connectors of the IC area 14, reducing interference and signal attenuation and ensuring the reliability of electrical connections. At the same time, the window area 17 being far away from the bend 12 can prevent copper foil breakage or cover film warping when the bend 12 is bent, and avoid product damage due to stress tension.

[0035] Furthermore, as a preferred embodiment of this solution and not a limitation, the other side of the main board 1 is provided with multiple openings for improving heat dissipation. These openings can further improve heat conduction efficiency, ensuring the normal operation of the IC area 14.

[0036] Furthermore, as a preferred embodiment of this solution and not a limitation, the board body 1 includes an exposed copper area 18 disposed on one side of the window area 17. By providing an exposed copper area 18 in the window area 17, the electrical performance, manufacturing feasibility, and functional expandability of the circuit can be optimized by exposing the copper foil traces, while also enhancing heat dissipation performance.

[0037] The working principle of this embodiment is as follows:

[0038] This utility model proposes an FPC flexible circuit board, which reduces the bending stress of the ribbon cable by providing a bending portion 12 between the main body 1 and the pin end 11 for protecting the board. This protects the circuit when the ribbon cable is bent and avoids the anisotropic conductive adhesive film from peeling off due to stress tension. Its specific working principle is as follows:

[0039] The bending portion 12 includes a softened single-layer region 121 and a composite region 122 adjacent to the single-layer region 121 for improving structural strength. A coating layer 16 covered with solder resist ink is provided on the board body 1 on the same side as the pin end 112, corresponding to the position of the bending portion 12. The single-layer region 121 and the composite region 122 can form a structure that is easy to bend. At the same time, the single-layer region 121 is softened, which can further optimize the stress at the bending portion 12 and avoid stress pulling that causes the anisotropic conductive adhesive film to peel off and fail. In addition, the coating layer 16 can enhance the mechanical strength of the bending portion 12, provide additional protection, prevent the circuit from breaking due to stress, and improve the bending resistance and life of the FPC flexible circuit board.

Claims

1. A flexible printed circuit board (FPC), characterized in that, It includes a board body (1) for accommodating fixed circuits, a pin end (11) is provided on one side of the board body (1), and a bent portion (12) for protecting the board is provided between the board body (1) and the pin end (11).

2. The FPC flexible circuit board according to claim 1, characterized in that, The bending portion (12) includes a single-layer area (121) that has been softened and a composite area (122) adjacent to the single-layer area (121) for improving structural strength. The single-layer area (121) and the composite area (122) are located on the same side as the main body of the plate (1).

3. The FPC flexible circuit board according to claim 1, characterized in that, The plate body (1) is provided with a coating layer (16) covered with solder resist ink at the position corresponding to the position of the bent part (12) on the same side of the pin end (11).

4. The FPC flexible circuit board according to claim 3, characterized in that, The pin terminal (11) is located on one side of the plate body (1). The pin terminal (11) includes a first pin terminal (111) and a second pin terminal (112). A first electromagnetic membrane region (13) is provided between the first pin terminal (111) and the second pin terminal (112).

5. The FPC flexible circuit board according to claim 2, characterized in that, The other side of the main body (1) of the board has an IC area (14) for installing circuits.

6. The FPC flexible circuit board according to claim 5, characterized in that, A second electromagnetic film region (15) is provided between the IC region (14) and the single-layer region (121).

7. The FPC flexible circuit board according to claim 1, characterized in that, The main body of the plate (1) is made of polyimide or polyester material.

8. The FPC flexible circuit board according to claim 5, characterized in that, The main body of the plate (1) has a window area (17) on one side and multiple window openings for improving heat dissipation on the other side.

9. The FPC flexible circuit board according to claim 8, characterized in that, The window area (17) is close to the IC area (14), and the window area (17) is far away from the bend (12).

10. The FPC flexible circuit board according to claim 8, characterized in that, The main body of the board (1) includes an exposed copper area (18) disposed on one side of the window area (17).

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