A flexible circuit board structure

Abstract

The utility model discloses a flexible circuit board structure, including flexible circuit board main part, the flexible circuit board main part is set gradually from below to above as flexible base layer, conductive circuit layer, insulating layer and protection layer, the conductive circuit layer sets up at the upper surface of flexible base layer, the insulating layer covers the upper surface of conductive circuit layer, be provided with the reinforcing rib that adopts polyimide composite material and has added glass fiber reinforcing agent inside in the lower surface of flexible base layer, and the reinforcing rib can play the effective supporting effect to flexible base layer, and the structural strength of reinforcing base layer is strengthened to improve the bending -resistant performance of flexible circuit board, avoid the fracture phenomenon that circuit layer appears after long -term repeated bending, prolong the service life of flexible circuit board, set up graphene heat conduction coating through the heat dissipation channel of setting up inside insulating layer and on the channel inner wall, can fast conduct the heat that circuit layer produces to the outside, and the heat dissipation channel of matrix type distribution ensures that heat evenly radiates.

Description

Technical Field

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

[0002] Flexible circuit boards, with their thinness and flexibility, are widely used in electronic products such as smartphones, laptops, and smart wearable devices. As the integration level of electronic products continues to increase, the power density of electronic components on flexible circuit boards is gradually increasing, and the heat generated is also increasing accordingly.

[0003] However, the heat of existing flexible circuit boards cannot be dissipated in time, which can easily lead to damage to electronic components due to overheating, affecting the normal operation of electronic products. After repeated bending over a long period of time, the circuit layer of the flexible circuit board is prone to breakage, resulting in circuit continuity failure and shortening the service life of the flexible circuit board. In addition, the surface protective layer of existing flexible circuit boards usually uses a single insulating material, which is easily damaged when subjected to external impact, friction or chemical corrosion, thus affecting the safety and stability of the circuit layer. Therefore, we propose a flexible circuit board structure. Summary of the Invention

[0004] To overcome the shortcomings of existing technologies, this utility model provides a flexible circuit board structure. Reinforcing ribs made of polyimide composite material with added glass fiber reinforcement are set on the lower surface of the flexible base layer. These ribs effectively support the flexible base layer, enhancing its structural strength and improving the flexible circuit board's bending resistance. This prevents the circuit layer from breaking after repeated bending over a long period, extending the lifespan of the flexible circuit board. By creating heat dissipation channels within the insulation layer and applying a graphene thermally conductive coating to the inner walls of these channels, heat generated by the circuit layer can be quickly conducted to the outside. The matrix-distributed heat dissipation channels ensure uniform heat distribution, effectively solving the problem of poor heat dissipation in existing flexible circuit boards. A wear-resistant layer improves the wear resistance of the flexible circuit board surface, preventing surface scratches. An anti-corrosion layer resists the erosion of external chemicals, protecting the circuit layer from damage. A buffer layer cushions impacts, reducing their effect on the circuit layer, comprehensively improving the protective performance of the flexible circuit board.

[0005] To solve the above technical problems, this utility model provides the following technical solution: a flexible circuit board structure, comprising a flexible circuit board body, wherein the flexible circuit board body is configured from bottom to top as a flexible base layer, a conductive circuit layer, an insulating layer, and a protective layer, the conductive circuit layer is disposed on the upper surface of the flexible base layer, the insulating layer covers the upper surface of the conductive circuit layer, the insulating layer is made of epoxy resin material, the insulating layer is tightly bonded to the conductive circuit layer by a thermosetting process, the protective layer is disposed on the upper surface of the insulating layer, and a plurality of reinforcing ribs are spaced apart on the lower surface of the flexible base layer, the reinforcing ribs being arranged along the length of the flexible base layer. Extending in the degree direction, the reinforcing rib and the flexible base layer are integrally formed. The insulation layer has several heat dissipation channels inside, which penetrate the insulation layer along its thickness direction. The heat dissipation channels are distributed in a matrix within the insulation layer, with equal spacing between adjacent heat dissipation channels. A thermally conductive coating is provided on the inner wall of the heat dissipation channel. The thermally conductive coating is made of graphene material. The protective layer consists of a wear-resistant layer, an anti-corrosion layer, and a buffer layer from top to bottom. The wear-resistant layer is made of alumina ceramic material, the anti-corrosion layer is made of polytetrafluoroethylene material, and the buffer layer is made of silicone material.

[0006] As a preferred technical solution of this utility model, a conductive circuit layer is formed on the flexible substrate by photolithography and etching processes. The conductive circuit layer is made of copper foil material and is fixed to the upper surface of the flexible substrate by lamination. The conductive circuit layer includes signal lines for transmitting signals and grounding lines for grounding. The conductive circuit layer is configured as arc-shaped traces in the preset bending area of ​​the flexible circuit board. The main surface of the flexible circuit board is covered with a cover film, and a metal shielding layer is provided on the outer surface of the cover film. The metal shielding layer is electrically connected to the grounding lines in the conductive circuit layer through conductive vias penetrating the flexible substrate and the cover film. The metal shielding layer is a copper layer formed by electroplating.

[0007] As a preferred embodiment of this utility model, the cross-section of the reinforcing rib is trapezoidal, the upper base of the trapezoid of the reinforcing rib is connected to the lower surface of the flexible base layer, and the width of the lower base of the trapezoid of the reinforcing rib is greater than the width of the upper base.

[0008] As a preferred technical solution of this utility model, the flexible base layer and the covering film are both made of polyimide flexible material, the reinforcing ribs are made of polyimide composite material, and glass fiber reinforcing agent is added inside the reinforcing ribs.

[0009] As a preferred technical solution of this utility model, the upper surface of the wear-resistant layer is provided with a plurality of anti-slip protrusions, the anti-slip protrusions are hemispherical in shape, and the anti-slip protrusions and the wear-resistant layer are integrally formed.

[0010] As a preferred embodiment of this utility model, the covering film has multiple hollowed-out grooves at the locations corresponding to the preset bending areas.

[0011] Compared with the prior art, the beneficial effects of this utility model are as follows: 1. By setting reinforcing ribs made of polyimide composite material with added glass fiber reinforcement on the lower surface of the flexible base layer, the reinforcing ribs can effectively support the flexible base layer, enhance the structural strength of the base layer, thereby improving the bending resistance of the flexible circuit board, avoiding the breakage of the circuit layer after long-term repeated bending, and extending the service life of the flexible circuit board. By opening heat dissipation channels inside the insulation layer and setting graphene thermal conductive coating on the inner wall of the channels, the heat generated by the circuit layer can be quickly conducted to the outside. The matrix-distributed heat dissipation channels ensure uniform heat dissipation, effectively solving the problem of poor heat dissipation of existing flexible circuit boards. The wear-resistant layer can improve the wear resistance of the flexible circuit board surface and prevent surface scratches. The anti-corrosion layer can resist the erosion of external chemicals and protect the circuit layer from damage. The buffer layer can buffer when subjected to external impact, reducing the impact on the circuit layer, and comprehensively improving the protective performance of the flexible circuit board.

[0012] 2. A metal shielding layer is formed directly on the cover film through electroplating, resulting in a compact structure, strong adhesion, and high shielding consistency. It is connected to the grounding line through conductive vias, forming a complete grounding shielding cavity, which effectively suppresses electromagnetic interference. By opening hollow grooves on the surface of the cover film, the rigidity of the cover film during bending is further reduced, allowing the stress to be distributed more evenly, effectively preventing fatigue fracture of the conductive line layer, and significantly improving the dynamic bending life of the flexible circuit board. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the cross-sectional structure of the circuit board of this utility model.

[0014] Figure 2 This is a schematic diagram of the heat dissipation channel distribution structure of the insulating layer of this utility model.

[0015] Figure 3 This is a schematic diagram of the cross-sectional structure of the protective layer of this utility model.

[0016] Figure 4 This is a top view of the partial bend of this utility model.

[0017] The components include: 1. Flexible base layer; 2. Conductive circuit layer; 3. Insulation layer; 4. Protective layer; 5. Reinforcing rib; 6. Heat dissipation channel; 7. Thermally conductive coating; 8. Wear-resistant layer; 9. Anti-corrosion layer; 10. Buffer layer; 11. Anti-slip protrusion; 12. Covering film; 13. Conductive through hole; 14. Hollowed-out groove. Detailed Implementation

[0018] To make the technical means, creative features, and achieved objectives and effects of this utility model easier to understand, the present utility model is further described below with reference to specific embodiments. However, the following embodiments are merely preferred embodiments of this utility model and not all of them. Other embodiments obtained by those skilled in the art based on the embodiments described in the implementation are all within the protection scope of this utility model without creative effort.

[0019] For an example, please refer to... Figure 1 , Figure 2 , Figure 3 As shown, this utility model provides a flexible circuit board structure, including a flexible circuit board body. The flexible circuit board body is arranged from bottom to top as a flexible base layer 1, a conductive circuit layer 2, an insulating layer 3, and a protective layer 4. The conductive circuit layer 2 is disposed on the upper surface of the flexible base layer 1. The insulating layer 3 covers the upper surface of the conductive circuit layer 2 and is made of epoxy resin. The insulating layer 3 is tightly bonded to the conductive circuit layer 2 through a thermosetting process. The protective layer 4 is disposed on the upper surface of the insulating layer 3. A plurality of reinforcing ribs 5 are spaced apart on the lower surface of the flexible base layer 1. The reinforcing ribs 5 extend along the flexible base layer 1... The base layer 1 extends along its length, and the reinforcing ribs 5 and the flexible base layer 1 are integrally formed. Several heat dissipation channels 6 are formed inside the insulation layer 3, penetrating the insulation layer 3 along its thickness. The heat dissipation channels 6 are distributed in a matrix within the insulation layer 3, with equal spacing between adjacent channels. A thermally conductive coating 7, made of graphene material, is applied to the inner wall of the heat dissipation channels 6. The protective layer 4 consists of, from top to bottom, a wear-resistant layer 8, an anti-corrosion layer 9, and a buffer layer 10. The wear-resistant layer 8 is made of alumina ceramic material, and the anti-corrosion layer 9 is made of... Made of polytetrafluoroethylene, the buffer layer 10 is made of silicone. Reinforcing ribs 5, made of polyimide composite material and reinforced with glass fiber, are provided on the lower surface of the flexible base layer 1. These ribs effectively support the flexible base layer 1, enhancing its structural strength and improving its bending resistance. This prevents the circuit layer from breaking after repeated bending and extends the lifespan of the flexible circuit board. Heat dissipation channels 6 are created inside the insulating layer 3, and a graphene thermally conductive coating 7 is applied to the inner wall of these channels. This allows for rapid heat transfer from the circuit layer to the outside. The matrix-distributed heat dissipation channels 6 ensure uniform heat distribution, effectively solving the problem of poor heat dissipation in existing flexible circuit boards. The protective layer 4 consists of a wear-resistant layer 8, an anti-corrosion layer 9, and a buffer layer 10. The wear-resistant layer 8 improves the wear resistance of the flexible circuit board surface, preventing scratches. The anti-corrosion layer 9 resists external chemical corrosion, protecting the circuit layer from damage. The buffer layer 10 cushions impacts, reducing their effect on the circuit layer and comprehensively improving the protective performance of the flexible circuit board.

[0020] like Figure 1 , Figure 4 As shown, a conductive circuit layer 2 is formed on the flexible substrate 1 through photolithography and etching processes. The conductive circuit layer 2 is made of copper foil material and is fixed to the upper surface of the flexible substrate 1 by a lamination process. The conductive circuit layer 2 includes signal lines for transmitting signals and grounding lines for grounding. The conductive circuit layer 2 is configured as arc-shaped traces in the preset bending area of ​​the flexible circuit board. The main surface of the flexible circuit board is covered with a cover film 12, and a metal shielding layer is provided on the outer surface of the cover film 12. The metal shielding layer is electrically connected to the grounding line in the conductive circuit layer 2 through conductive vias 13 that penetrate the flexible substrate 1 and the cover film 12. The metal shielding layer is a copper layer formed by electroplating. The metal shielding layer is formed directly on the cover film 12 by electroplating, resulting in a compact structure, strong adhesion, and high shielding consistency. It is connected to the grounding line through the conductive vias 13, forming a complete grounding shielding cavity, which effectively suppresses electromagnetic interference.

[0021] like Figure 1 As shown, the cross-section of the reinforcing rib 5 is trapezoidal, and the upper base of the trapezoid of the reinforcing rib 5 is connected to the lower surface of the flexible base layer 1. The width of the lower base of the trapezoid of the reinforcing rib 5 is greater than the width of the upper base.

[0022] like Figure 1 , Figure 4 As shown, the flexible base layer 1 and the covering film 12 are both made of polyimide flexible material, and the reinforcing rib 5 is made of polyimide composite material. Glass fiber reinforcement is added inside the reinforcing rib 5.

[0023] like Figure 3 As shown, the upper surface of the wear-resistant layer 8 is provided with several anti-slip protrusions 11. The anti-slip protrusions 11 have a hemispherical structure and are integrally formed with the wear-resistant layer 8.

[0024] like Figure 4 As shown, the cover film 12 has multiple hollow grooves 14 at the locations corresponding to the preset bending areas; by opening hollow grooves 14 on the surface of the cover film 12, the rigidity of the cover film 12 during bending is further reduced, so that the stress can be distributed more evenly, effectively preventing fatigue fracture of the conductive circuit layer 2, and significantly improving the dynamic bending life of the flexible circuit board.

[0025] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A flexible circuit board structure, comprising a flexible circuit board body, characterized in that: The flexible circuit board body is arranged from bottom to top as follows: a flexible base layer (1), a conductive circuit layer (2), an insulating layer (3), and a protective layer (4). The conductive circuit layer (2) is disposed on the upper surface of the flexible base layer (1), and the insulating layer (3) covers the upper surface of the conductive circuit layer (2). The insulating layer (3) is made of epoxy resin and is tightly bonded to the conductive circuit layer (2) by a thermosetting process. The protective layer (4) is disposed on the upper surface of the insulating layer (3). Several reinforcing ribs (5) are spaced apart on the lower surface of the flexible base layer (1). The reinforcing ribs (5) extend along the length of the flexible base layer (1) and are integrally formed with the flexible base layer (1). The structure includes several heat dissipation channels (6) inside the insulating layer (3). The heat dissipation channels (6) penetrate the insulating layer (3) along the thickness direction. The heat dissipation channels (6) are distributed in a matrix in the insulating layer (3). The spacing between two adjacent heat dissipation channels (6) is equal. A thermally conductive coating (7) is provided on the inner wall of the heat dissipation channel (6). The thermally conductive coating (7) is made of graphene material. The protective layer (4) consists of a wear-resistant layer (8), an anti-corrosion layer (9), and a buffer layer (10) from top to bottom. The wear-resistant layer (8) is made of alumina ceramic material. The anti-corrosion layer (9) is made of polytetrafluoroethylene material. The buffer layer (10) is made of silicone material.

2. The flexible circuit board structure according to claim 1, characterized in that: A conductive circuit layer (2) is formed on the flexible substrate (1) by photolithography and etching. The conductive circuit layer (2) is made of copper foil material. The conductive circuit layer (2) is fixed on the upper surface of the flexible substrate (1) by lamination. The conductive circuit layer (2) includes signal lines for transmitting signals and grounding lines for grounding. The conductive circuit layer (2) is configured as arc-shaped traces in the preset bending area of ​​the flexible circuit board. The main surface of the flexible circuit board is covered with a cover film (12). A metal shielding layer is provided on the outer surface of the cover film (12). The metal shielding layer is electrically connected to the grounding line in the conductive circuit layer (2) through conductive vias (13) that penetrate the flexible substrate (1) and the cover film (12). The metal shielding layer is a copper layer formed by electroplating.

3. The flexible circuit board structure according to claim 1, characterized in that: The cross-section of the reinforcing rib (5) is trapezoidal, the upper base of the trapezoid of the reinforcing rib (5) is connected to the lower surface of the flexible base layer (1), and the width of the lower base of the trapezoid of the reinforcing rib (5) is greater than the width of the upper base.

4. The flexible circuit board structure according to claim 1, characterized in that: The flexible base layer (1) and the covering film (12) are both made of polyimide flexible material.

5. A flexible circuit board structure according to claim 1, characterized in that: The upper surface of the wear-resistant layer (8) is provided with a number of anti-slip protrusions (11). The anti-slip protrusions (11) are hemispherical in shape and are integrally formed with the wear-resistant layer (8).

6. A flexible circuit board structure according to claim 2, characterized in that: The covering film (12) has multiple hollowed-out grooves (14) at the locations corresponding to the preset bending areas.

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