Flexible circuit board and manufacturing method thereof

Abstract

The invention discloses a flexible circuit board and a manufacturing method thereof. The flexible circuit board comprises a circuit substrate and a covering film, the covering films are arranged on a first surface and a second surface, which are opposite to each other, of the circuit substrate; the circuit substrate comprises a valid circuit area and an invalid circuit area; a copper layer is arranged between the invalid circuit area and the covering film; the copper layer is provided with a glue guide groove used for communicating the effective circuit area with the external environment. According to the invention, through structure optimization, high-efficiency exhaust and gummosis in the circuit board pressing process can be completed without drilling.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit board design, and in particular to a flexible circuit board and a manufacturing method thereof. Background Art

[0002] In the manufacturing process of rigid-flexible printed circuits (RFPCs), the coverlay lamination process is a critical step in ensuring product quality. Existing industry-standard lamination solutions typically require the creation of vent holes with a diameter of 1.0-2.0mm in the waste area. This drilling process facilitates air venting and the smooth removal of adhesive during lamination. However, this traditional approach has the following drawbacks: 1. Process complexity: This traditional approach requires an additional drilling step, which not only prolongs the production process but also increases reliance on consumables such as drill bits and phenolic board, making the production process more cumbersome. 2. High cost: The drilling process not only consumes drilling equipment but also increases labor costs. Furthermore, the waste generated during the drilling process requires specialized handling, further increasing environmental costs and leading to higher overall production costs. 3. Limited production efficiency: The drilling process significantly extends the production cycle, making it difficult to meet the efficiency and speed requirements of large-scale automated production, thus limiting production efficiency improvements. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a flexible circuit board and a manufacturing method thereof, which can achieve efficient exhaust and glue flow during the circuit board pressing process without drilling through structural optimization.

[0004] In order to solve the above technical problems, a technical solution adopted by the present invention is: A flexible circuit board comprises a circuit substrate and a cover film; The covering film is provided on both the first and second opposite surfaces of the circuit substrate; The circuit substrate includes an effective circuit area and an ineffective circuit area; A copper layer is provided between the ineffective circuit area and the cover film; The copper layer is provided with a glue guide groove for connecting the effective circuit area with the external environment.

[0005] In order to solve the above technical problems, another technical solution adopted by the present invention is: A method for manufacturing a flexible circuit board, comprising the steps of: Providing a circuit substrate, and determining an effective circuit area and an ineffective circuit area of ​​the circuit substrate; Copper layers are respectively covered on the first surface and the second surface opposite to the ineffective circuit area; forming a glue guide groove on the copper layer for connecting the effective circuit area with the external environment; Cover films are respectively attached to the first and second opposite surfaces of the circuit substrate and pressed together.

[0006] The beneficial effects of the present invention are as follows: covering films are provided on both sides of the circuit substrate to ensure protection of the effective circuit area during the lamination process; by dividing the effective circuit area into an ineffective circuit area, a copper layer is added between the ineffective circuit area and the covering film, and a glue guide groove is provided on the copper layer. The glue guide groove is used to directly connect the effective circuit area with the external environment, thereby achieving smooth flow of colloid and gas discharge during the lamination process, thereby eliminating the need for a drilling process. By optimizing the structural design of the ineffective circuit area in the circuit substrate, the present invention utilizes the structural rigidity of the copper layer to realize the glue guide channel. This allows efficient gas exhaust and glue flow during the circuit board lamination process without drilling, thereby simplifying the production process, reducing the consumption cost caused by the drilling process, and improving the lamination efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 A side stacking pattern of a circuit substrate provided by an embodiment of the present invention; Figure 2 A side stacking pattern of a flexible circuit board without a glue guide groove provided in an embodiment of the present invention; Figure 3 A schematic diagram of an effective circuit area and an ineffective circuit area provided by an embodiment of the present invention; Figure 4 A side stacking pattern of a flexible circuit board with a glue guide groove provided in an embodiment of the present invention; Figure 5 A side stacking pattern of a copper layer provided by an embodiment of the present invention; Figure 6 A schematic cross-sectional view of a glue guide groove provided in an embodiment of the present invention; Figure 7 A schematic cross-sectional view of another glue guide groove provided by an embodiment of the present invention; Figure 8 A schematic plan view of a flexible circuit board provided with a glue guide groove according to an embodiment of the present invention; Figure 9 for Figure 8 A schematic plan view of the first unit area in the lower left corner; Figure 10 A flowchart of a method for manufacturing a flexible circuit board provided in an embodiment of the present invention; Description of labels: 1. Circuit board; 11. Polyimide base film layer; 12. Base conductor layer; 13. Polypropylene material layer; 14. Secondary base material layer; 15. Copper plating layer; 16. Mask layer; 17. Conductive adhesive layer; 18. Steel sheet layer; 101. Active circuit area; 102. Inactive circuit area; 1011. First unit area; 1012. Second unit area. 2. Covering film; 21. Thin film layer; 22. Glue layer; 3. Copper layer; 31. Glue guide groove; 301. First sub-copper layer; 302. Second sub-copper layer; 311. First gluon guide groove; 312. Second gluon guide groove; 313. Third gluon guide groove. DETAILED DESCRIPTION

[0008] To illustrate the technical content, achieved objectives and effects of the present invention in detail, the following description is given in conjunction with the embodiments and accompanying drawings.

[0009] An embodiment of the present invention provides a flexible circuit board, comprising a circuit substrate and a cover film; The covering film is provided on both the first and second opposite surfaces of the circuit substrate; The circuit substrate includes an effective circuit area and an ineffective circuit area; A copper layer is provided between the ineffective circuit area and the cover film; The copper layer is provided with a glue guide groove for connecting the effective circuit area with the external environment.

[0010] From the above description, it can be seen that the beneficial effects of the present invention are: providing a covering film on both sides of the circuit substrate to ensure protection of the effective circuit area during the lamination process; by dividing the effective circuit area and the invalid circuit area, adding a copper layer between the invalid circuit area and the covering film, providing a glue guide groove on the copper layer, and using the glue guide groove to directly connect the effective circuit area with the external environment, thereby achieving smooth flow of colloid and gas discharge during the lamination process, thereby eliminating the need to rely on the drilling process. The present invention optimizes the structural design of the invalid circuit area in the circuit substrate, thereby utilizing the structural rigidity of the copper layer to realize the glue guide channel, and can complete efficient exhaust and glue flow during the circuit board lamination process without drilling, thereby simplifying the production process, reducing the consumption cost caused by the drilling process, and improving the lamination efficiency.

[0011] Furthermore, the effective circuit area includes a plurality of first unit areas provided with combined circuit patterns; The first unit area includes a plurality of second unit areas provided with basic circuit patterns; The glue guiding groove includes a first glue guiding sub-groove; In the same first unit region, a first gluon conducting groove is provided on the copper layer between two adjacent second unit regions, and the first gluon conducting groove is used to connect the two adjacent second unit regions of the first unit region.

[0012] As can be seen from the above description, the effective circuit area is decomposed into multiple first unit areas containing combined circuit patterns, and each first unit area is further subdivided into second unit areas containing basic circuit patterns, forming a hierarchical circuit layout. By setting a first glue guide groove on the copper layer between adjacent second unit areas in the same first unit area, a glue guide channel is established between adjacent basic circuit units, so that the colloid can flow along the preset glue guide path during the pressing process, which not only ensures the uniform distribution of colloid between adjacent basic circuit units, but also replaces traditional drilling with the directional glue guide groove on the copper layer, avoiding the equipment investment and waste disposal problems caused by the additional drilling process. The hierarchical unit area division and the distribution setting of the glue guide groove realize the directional glue control in the local area, ensuring the effective circuit area to form a controllable connection with the external environment, while maintaining the integrity of the circuit structure.

[0013] Furthermore, the glue guiding groove further includes a second glue guiding sub-groove; In two different first unit regions, a second gluon conducting groove is provided on the copper layer between two adjacent second unit regions, and the second gluon conducting groove is used to connect two adjacent second unit regions of the two first unit regions.

[0014] As can be seen from the above description, by setting a second glue-conducting sub-groove between adjacent second unit areas across the first unit area, a glue-conducting channel across the unit area is constructed. The addition of the second glue-conducting sub-groove allows a connecting path to be formed between the second unit areas that originally belonged to different first unit areas, breaking through the physical isolation limitations between the unit areas. This design not only replaces the traditional drilling process with a preset glue-conducting groove on the copper layer, but also realizes the flow of glue across the unit area, allowing the glue to diffuse outward from the effective circuit area along a predetermined path. By optimizing the spatial distribution structure of the glue-conducting groove, the glue-conducting function is extended from the inside of a single unit to the interface area of ​​multiple units, thereby solving the problem of exhaust and glue discharge during the pressing of large-size or complex layout circuit boards without the need for additional drilling.

[0015] Furthermore, the glue guiding groove further includes a third glue guiding sub-groove; The third gluon-conducting groove is provided on the copper layer between the second unit area and the edge of the circuit substrate, and the third gluon-conducting groove is used to connect the second unit area with the external environment.

[0016] As can be seen from the above description, by providing a third glue guide groove on the copper layer between the second unit area and the edge of the circuit substrate, direct connection between the second unit area and the external environment is achieved. As part of the glue guide groove, the third glue guide groove is located between the second unit area and the edge of the circuit substrate, which can effectively guide the glue to flow from the second unit area to the external environment. This design avoids the need to drill holes in the waste area in the traditional method, simplifies the process flow and reduces the cost of the drilling process. The connecting function of the third glue guide groove allows the gas and excess colloid generated during the pressing process to be naturally discharged through the structure without relying on additional drilling processes, thereby reducing production costs and improving production efficiency.

[0017] Furthermore, the copper layer includes a first sub-copper layer and a second sub-copper layer; The first sub-copper layer is provided between the first surface of the ineffective circuit area and the cover film; The second sub-copper layer is provided between the second surface of the ineffective circuit area and the covering film; The glue guiding grooves on the first sub-copper layer and the second sub-copper layer are staggered.

[0018] As can be seen from the above description, the copper layer comprises two independently arranged sub-copper layers, and the glue guide slots on both sub-copper layers are staggered, optimizing the spatial distribution of the glue flow path and exhaust channel. The first and second sub-copper layers correspond to the lamination requirements of the double-sided cover film of the circuit substrate, achieving double-sided glue flow. The staggered arrangement of the glue guide slots enhances the structural rigidity of the inactive circuit area, preventing deformation of the inactive circuit area during lamination due to the lack of rigid support from the copper layer, thereby avoiding the problem of glue guide slot clogging due to deformation, effectively improving lamination reliability and product quality.

[0019] Furthermore, the glue guiding groove is tilted so that the glue guiding groove forms a preset angle relative to a horizontal plane.

[0020] As can be seen from the above description, by designing the glue guide groove with an inclined structure and forming it at a specific angle with the horizontal plane, the glue flow path and exhaust efficiency are optimized. The inclined glue guide groove can increase the groove capacity, allowing the glue to flow more smoothly through the glue guide groove during the process, reducing glue accumulation and retention in the groove, thereby optimizing the glue flow path.

[0021] Furthermore, the thickness of the copper layer is greater than or equal to 12 micrometers and less than or equal to 35 micrometers.

[0022] As can be seen from the above description, limiting the copper layer thickness to a range of 12 to 35 microns strikes a balance between structural strength and process cost. When the copper layer thickness is less than 12 microns, its mechanical strength is insufficient to support the adhesive guide grooves in the stress generated by the colloid flow during the lamination process, potentially causing deformation or fracture of the copper layer, which in turn affects the adhesive conduction and venting functions. When the thickness exceeds 35 microns, while the structural strength is improved, the material cost increases significantly and the processing becomes more difficult. Furthermore, an excessively thick copper layer can affect the lamination quality of the circuit board. This thickness range ensures that the adhesive guide grooves effectively guide the colloid flow and exhaust gas during lamination, while also avoiding process defects caused by excessively thick copper layers. This replaces traditional drilling and venting solutions and simplifies the production process.

[0023] Furthermore, the width of the glue guiding groove is greater than or equal to 1.5 mm and less than or equal to 2 mm.

[0024] As can be seen from the above description, the 1.5mm minimum width of the adhesive guide slot ensures sufficient cross-sectional area for the adhesive during the lamination process, avoiding flow obstruction or poor venting caused by an overly narrow slot. The 2mm maximum width prevents structural strength loss and material waste caused by an overly wide slot. This size range balances process requirements with structural reliability, meeting the physical requirements of adhesive and gas discharge during lamination while avoiding damage to the PCB's structural integrity.

[0025] Furthermore, the covering film includes a film layer and an adhesive layer; The adhesive layer is respectively covered on the first and second opposite surfaces of the circuit substrate; The film layer is attached to one side of the adhesive layer away from the circuit substrate.

[0026] From the above description, it can be seen that the covering film is composed of a thin film layer and an adhesive layer. The adhesive layer directly covers the upper and lower surfaces of the circuit substrate to ensure effective contact between the colloid and the substrate, so that the colloid flows based on the glue guide groove on the copper layer during pressing, and exhaust and glue flow control can be completed without additional drilling.

[0027] Another embodiment of the present invention provides a method for manufacturing a flexible circuit board, comprising the steps of: Providing a circuit substrate, and determining an effective circuit area and an ineffective circuit area of ​​the circuit substrate; Copper layers are respectively covered on the first surface and the second surface opposite to the ineffective circuit area; forming a glue guide groove on the copper layer for connecting the effective circuit area with the external environment; Cover films are respectively attached to the first and second opposite surfaces of the circuit substrate and pressed together.

[0028] From the above description, it can be seen that the beneficial effects of the present invention are: providing a covering film on both sides of the circuit substrate to ensure protection of the effective circuit area during the lamination process; by dividing the effective circuit area and the invalid circuit area, adding a copper layer between the invalid circuit area and the covering film, providing a glue guide groove on the copper layer, and using the glue guide groove to directly connect the effective circuit area with the external environment, thereby achieving smooth flow of colloid and gas discharge during the lamination process, thereby eliminating the need to rely on the drilling process. The present invention optimizes the structural design of the invalid circuit area in the circuit substrate, thereby utilizing the structural rigidity of the copper layer to realize the glue guide channel, and can complete efficient exhaust and glue flow during the circuit board lamination process without drilling, thereby simplifying the production process, reducing the consumption cost caused by the drilling process, and improving the lamination efficiency.

[0029] The flexible circuit board and its manufacturing method described above can be applied to the scenario where the flexible circuit board undergoes a cover film lamination process. By optimizing the structure, efficient exhaust and glue flow can be achieved during the circuit board lamination process without drilling. The following is an explanation of the specific implementation method: Please refer to Figures 1 to 9 , embodiment 1 of the present invention is: like Figure 1 As shown, a flexible circuit board includes a circuit substrate 1 and a cover film 2. Cover films 2 are provided on both the first and second opposing surfaces of the circuit substrate 1. The first and second opposing surfaces of the circuit substrate 1 are the upper and lower surfaces, respectively. Cover film 2 includes a film layer 21 and an adhesive layer 22. The adhesive layer 22 covers both the first and second opposing surfaces of the circuit substrate 1, and the film layer 21 is attached to the side of the adhesive layer 22 facing away from the circuit substrate 1.

[0030] In some embodiments, the circuit substrate 1 includes a polyimide-based film layer 11 and a basic conductor layer 12 , and the basic conductor layer 12 is provided on both the upper and lower surfaces of the polyimide-based film layer 11 , wherein the basic conductor layer 12 is a copper layer for setting a specific circuit pattern.

[0031] In addition, the flexible circuit board can also include a polypropylene material layer 13, a secondary base material layer 14, a copper plating layer 15, a mask layer 16, a conductive adhesive layer 17 and a steel sheet layer 18. The polypropylene material layer 13, the secondary base material layer 14, the copper plating layer 15, the mask layer 16, the conductive adhesive layer 17 and the steel sheet layer 18 are stacked in order from the inside to the outside on the side of the cover film 2 away from the circuit substrate 1. Figure 2 The polypropylene material layer 13 is high glass transition temperature polypropylene, the secondary substrate layer 14 is an electroplated conductor layer, the mask layer 16 is solder paste mask oil for photosensitive imaging, and the steel sheet layer 18 is stainless steel.

[0032] The circuit substrate 1 includes an effective circuit area 101 and an ineffective circuit area 102, wherein the effective circuit area 101 refers to an area on the circuit substrate 1 covered with a circuit pattern, and the ineffective circuit area 102 refers to an area on the circuit substrate 1 not covered with a circuit pattern. Figure 3 As shown, since the basic conductor layer 12 in the circuit substrate 1 is a copper layer and is used to set a specific circuit pattern, the effective circuit area 101 refers to the area where the polyimide base film layer 11 is covered with a copper layer circuit pattern, and the invalid circuit area 102 refers to the area where the polyimide base film layer 11 is not covered with a copper layer circuit pattern.

[0033] like Figure 4 As shown, a copper layer 3 is provided between the ineffective circuit area 102 and the cover film 2 , and a glue guide groove 31 is provided on the copper layer 3 for connecting the effective circuit area 101 with the external environment.

[0034] like Figure 5 As shown, the copper layer 3 includes a first sub-copper layer 30101 and a second sub-copper layer 302. The first sub-copper layer 301 is disposed between the first surface of the inactive circuit region 102 and the cover film 2, and the second sub-copper layer 302 is disposed between the second surface of the inactive circuit region 102 and the cover film 2. In some embodiments, the first sub-copper layer 301 and the second sub-copper layer 302 are disposed on the upper and lower surfaces of the polyimide-based film layer 11, respectively. That is, the copper layer 3 used to provide the glue guide groove 31 is on the same horizontal plane as the base conductor layer 12 used to provide the circuit pattern.

[0035] like Figure 6 As shown, the glue guiding grooves 31 on the first copper sub-layer 301 and the second copper sub-layer 302 are staggered. In an optional embodiment, the staggered distance between the glue guiding grooves 31 on the first copper sub-layer 301 and the second copper sub-layer 302 is 2 mm.

[0036] In an optional embodiment, the adhesive conductive grooves 31 on the first sub-copper layer 301 and the second sub-copper layer 302 can be staggered according to spatial distribution. Specifically, the adhesive conductive layer 22 on the first sub-copper layer 301 is disposed on a side close to the active circuit area 101, and the adhesive conductive layer 22 on the second sub-copper layer 302 is disposed on a side away from the active circuit area 101.

[0037] In an optional embodiment, as Figure 7 As shown, the glue guide groove 31 is tilted, forming a predetermined angle relative to the horizontal plane. In this embodiment, the glue guide grooves 31 on the first sub-copper layer 301 and the second sub-copper layer 302 are located on the same straight line. However, due to the tilt of the glue guide grooves 31, the top of the glue guide groove 31 on the first sub-copper layer 301 and the bottom of the glue guide groove 31 on the second sub-copper layer 302 are not aligned, which can also achieve the same effect as the staggered arrangement.

[0038] In an optional embodiment, the thickness of the copper layer 3 is greater than or equal to 12 micrometers and less than or equal to 35 micrometers.

[0039] like Figure 8 and Figure 9 As shown, the effective circuit area 101 includes multiple first unit areas 1011 provided with combined circuit patterns, and the first unit areas 1011 include multiple second unit areas 1012 provided with basic circuit patterns. Specifically, a large flexible circuit board PNL may include multiple combined circuit boards SET, each provided with a combined circuit pattern, and a combined circuit board SET may include multiple basic circuit boards PCS, each provided with a basic circuit pattern. In other words, the first unit area 1011 is the combined circuit board SET, and the second unit area 1012 is the basic circuit board PCS. It should be noted that Figure 8 and Figure 9 Only the glue guide groove 31 of the first sub-copper layer 301 on the upper surface of the circuit substrate 11 is shown. The glue guide groove 31 of the second sub-copper layer 302 on the lower surface of the circuit board 11 is similar to the first sub-copper layer 301 and will not be described again here.

[0040] Among them, the glue guiding groove 31 includes a first glue guiding sub-groove 311. In the same first unit area 1011, the first glue guiding sub-groove 311 is set on the copper layer 3 between two adjacent second unit areas 1012. The first glue guiding sub-groove 311 is used to connect two second unit areas 1012 adjacent to a first unit area 1011.

[0041] Among them, the glue guiding groove 31 also includes a second glue guiding sub-groove 312. In two different first unit areas 1011, a second glue guiding sub-groove 312 is provided on the copper layer 3 between two adjacent second unit areas 1012. The second glue guiding sub-groove 312 is used to connect the two adjacent second unit areas 1012 of the two first unit areas 1011.

[0042] Among them, the glue guiding groove 31 also includes a third glue guiding groove 313. The third glue guiding groove 313 is provided on the copper layer 3 between the second unit area 1012 and the edge of the circuit substrate 1. The third glue guiding groove 313 is used to connect the second unit area 1012 with the external environment.

[0043] It should be noted that the glue guide groove 31 can achieve the exhaust effect because the glue flows in the glue guide groove 31 and the air between the circuit substrate 1 and the cover film 2 is discharged from the glue guide groove 31 based on the pressure difference formed when the glue flows.

[0044] In some embodiments, the glue guide grooves 31 are all straight grooves to avoid bending, thereby ensuring that the glue and gas in the glue guide grooves 31 can flow smoothly. In this case, when connecting different areas, the glue guide grooves 31 are not set according to the shortest straight-line distance between the two, but are set according to a diagonal line to increase the length of the glue guide grooves 31 as much as possible. This is because when designing circuit boards, in order to ensure the utilization rate of materials, the layout of the circuit graphics in the circuit boards is generally very tight. For example, when ensuring that there is no over-process capability during product molding, the spacing between graphics is generally only 3-5mm. Therefore, if it is set according to the shortest straight-line distance, the capacity of the glue guide grooves 31 will be small, and the glue flow path will be very short, and the gas between the circuit board and the covering film 2 cannot be discharged.

[0045] In an optional embodiment, the width of the glue guiding groove 31 is greater than or equal to 1.5 mm and less than or equal to 2 mm.

[0046] Please refer to Figure 10 , the second embodiment of the present invention is: A method for manufacturing a flexible circuit board, for providing the flexible circuit board described in the first embodiment, specifically comprises the steps of: S1. Provide a circuit substrate, and determine an effective circuit area and an ineffective circuit area of ​​the circuit substrate.

[0047] S2. Copper layers are respectively covered on the first surface and the second surface opposite to the inactive circuit area.

[0048] S3. Forming a glue conducting groove on the copper layer for connecting the effective circuit area with the external environment.

[0049] In some embodiments, a copper layer is first covered on the upper and lower surfaces of a polyimide-based film layer by electrolysis or calendering, and then the base conductor layer is exposed and developed using a film containing a circuit pattern and a glue guide groove. Finally, a base conductor layer containing a circuit pattern and a copper layer containing a glue guide groove are simultaneously formed on the polyimide-based film layer by etching.

[0050] S4, attaching cover films to the first and second opposite surfaces of the circuit substrate respectively and performing a lamination process.

[0051] In some embodiments, the cover film can be made of high-temperature resistant, low-viscosity epoxy resin or acrylic material. The cover film is attached to the circuit substrate with the adhesive guide groove and pressed according to the preset pressing process parameters. The pressing process parameters include a temperature range of 120-180°C, a pressure of 100kg / cm 2 , the holding time is 2-3 minutes.

[0052] In summary, the present invention provides a flexible circuit board and a method for manufacturing the same. By arranging a copper layer between the ineffective circuit area of ​​the flexible circuit board and the covering film, and cleverly designing glue guide grooves of different levels and directions on the copper layer, smooth flow of the colloid and efficient discharge of gas during the lamination process are achieved, completely replacing the traditional drilling process. This design not only simplifies the production process, reduces equipment investment, material waste and waste disposal costs caused by the drilling process, but also improves the lamination efficiency and product quality. At the same time, the thickness of the copper layer, the staggered layout of the glue guide grooves on the double-sided copper layer, the inclined setting of the glue guide grooves and the reasonable width further enhance the structural rigidity, optimize the colloid flow path, and ensure the reliability of the lamination process. In addition, the thin film layer and glue layer structure design of the covering film further ensure the effective contact between the colloid and the substrate, making the entire lamination process more efficient and stable, and significantly improving the production efficiency and performance of the flexible circuit board.

[0053] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent transformations made using the contents of the present invention's description and drawings, or directly or indirectly applied in related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A flexible circuit board, characterized in that: including a circuit substrate and a cover film; The covering film is provided on both the first and second opposite surfaces of the circuit substrate; The circuit substrate includes an effective circuit area and an ineffective circuit area; A copper layer is provided between the ineffective circuit area and the cover film; The copper layer is provided with a glue guide groove for connecting the effective circuit area with the external environment.

2. The flexible circuit board according to claim 1, wherein: The effective circuit area includes a plurality of first unit areas provided with combination circuit patterns; The first unit area includes a plurality of second unit areas provided with basic circuit patterns; The glue guiding groove includes a first glue guiding sub-groove; In the same first unit region, a first gluon conducting groove is provided on the copper layer between two adjacent second unit regions, and the first gluon conducting groove is used to connect the two adjacent second unit regions of the first unit region.

3. The flexible circuit board according to claim 2, characterized in that: The glue guiding groove further includes a second glue guiding sub-groove; In two different first unit regions, a second gluon conducting groove is provided on the copper layer between two adjacent second unit regions, and the second gluon conducting groove is used to connect two adjacent second unit regions of the two first unit regions.

4. The flexible circuit board according to claim 2, characterized in that: The glue guiding groove further includes a third glue guiding sub-groove; The third gluon-conducting groove is provided on the copper layer between the second unit area and the edge of the circuit substrate, and the third gluon-conducting groove is used to connect the second unit area with the external environment.

5. The flexible circuit board according to claim 1, wherein: The copper layer includes a first copper sub-layer and a second copper sub-layer; The first sub-copper layer is provided between the first surface of the ineffective circuit area and the cover film; The second sub-copper layer is provided between the second surface of the ineffective circuit area and the covering film; The glue guiding grooves on the first sub-copper layer and the second sub-copper layer are staggered.

6. The flexible circuit board according to claim 1, characterized in that: The glue guiding groove is tilted so that the glue guiding groove forms a preset angle relative to the horizontal plane.

7. The flexible circuit board according to claim 1, characterized in that: The copper layer has a thickness greater than or equal to 12 micrometers and less than or equal to 35 micrometers.

8. The flexible circuit board according to claim 1, wherein: The width of the glue guiding groove is greater than or equal to 1.5 mm and less than or equal to 2 mm.

9. The flexible circuit board according to claim 1, characterized in that: The covering film includes a film layer and an adhesive layer; The adhesive layer is respectively covered on the first and second opposite surfaces of the circuit substrate; The film layer is attached to one side of the adhesive layer away from the circuit substrate.

10. A method for manufacturing a flexible circuit board, characterized in that: Including steps: Providing a circuit substrate, and determining an effective circuit area and an ineffective circuit area of ​​the circuit substrate; Copper layers are respectively covered on the first surface and the second surface opposite to the ineffective circuit area; forming a glue guide groove on the copper layer for connecting the effective circuit area with the external environment; Cover films are respectively attached to the first and second opposite surfaces of the circuit substrate and pressed together.

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