FPC bending structure
By dislocating the copper laying areas of the first and second surface layers in the FPC bending structure, the thickness of the bending area is reduced and the bending protection is increased, the problem of stress concentration during bending causes the wiring channel to break, and smaller bending stress and higher bending performance are achieved.
Patent Information
- Application Number
- CN202421680750.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-16
- Publication Date
- 2025-06-17
- Estimated Expiration
- 2034-07-16
AI Technical Summary
When bending, the existing FPC bending structure increases stress at the junction of the two layers of copper foil, which leads to the risk of breaking the wiring channel.
By dislocating the copper-laying areas of the first and second surface layers, the thickness of the bending zone is reduced by one layer and an extension is added at the lower copper-laying area to provide additional bending protection, thereby avoiding stress concentration at the direct junction.
It effectively reduces bending stress, avoids the risk of breaking the trace channel, and improves the bending performance of FPC.
Smart Images
Figure CN222996740U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of flexible printed circuit boards, and particularly relates to an FPC bending structure. Background Art
[0002] Flexible printed circuit boards (FPCs) are also known as flexible circuit boards, flexible flat cables, etc. It is a printed circuit board with high flexibility that can be freely bent and folded, mainly made of an insulating substrate (such as polyimide or polyester film) and copper foil through processes such as pressing, bonding, and copper foil etching. Printed components and printed circuits with conductive paths can be formed on the FPC to achieve the connection between electronic components.
[0003] In order to reduce the interference of external signals on the FPC and improve the performance of the FPC, we usually perform copper plating operations on the FPC. As Figure 1 shown, due to the presence of a reinforcing plate in the component area, solid copper plating is usually used. To avoid excessive bending of the FPC in the non-component area, grid copper is usually used.
[0004] As Figure 3 shown, in conventional copper plating, solid copper plating is used in the reinforcing area for both the upper and lower layer copper plating. Since the upper and lower layer copper plating is flush, at the junction of the solid copper plating and the grid copper plating, it is equivalent to increasing the height of two layers of copper foil, and the stress generated during the bending of the FPC is relatively large. There is a risk of breakage in the routing channel. Therefore, how to solve the risk of breakage in the bending area has become an urgent technical problem to be solved. Content of the Utility Model
[0005] The purpose of the utility model is to address the problems in the background art by proposing an FPC bending structure. By misaligning the copper plating areas of the first surface layer and the second surface layer, the thickness is reduced by one layer compared to before during bending, and the lower layer copper plating extends a little to increase bending protection, so that the junction at the bending part is not directly the junction of two layers of grid and solid copper. In this way, the bending stress is relatively small, and the routing channel will not break.
[0006] The technical solution of the utility model is an FPC bending structure, which includes a first surface layer and a second surface layer. Both the first surface layer and the second surface layer include a component area and a non-component area;
[0007] The component area on the first surface layer shrinks inward, and the component area on the second surface layer extends outward;
[0008] The connection between the component area and the non-component area is the bending area; after the first surface layer and the second surface layer are attached together, the bending area maintains a misaligned structure;
[0009] The first surface layer and the second surface layer are attached together, and multiple routing channels are reserved in the middle.
[0010] Preferably, the FPC is bent along the bending area in the direction from the component area towards the non-component area.
[0011] Preferably, a solid copper structure is laid on the component area.
[0012] Preferably, a grid copper structure is laid on the non-component area.
[0013] Preferably, after the first surface layer and the second surface layer are bonded together, the misalignment distance in the bending area is 1 - 2 mm.
[0014] Preferably, after the first surface layer and the second surface layer are bonded together, the misalignment distance in the bending area is 1.5 mm.
[0015] Preferably, the grid copper structure laid on the non-component area is a diamond grid.
[0016] Preferably, the grid copper structure laid on the non-component area is a circular grid.
[0017] Preferably, the grid copper structure laid on the non-component area is a honeycomb grid.
[0018] Preferably, the grid copper structure laid on the non-component area is a rectangular grid.
[0019] Compared with the prior art, the utility model has the following beneficial technical effects:
[0020] In the utility model, the solid copper structure in the component area on the first surface layer is contracted inward, and the solid copper structure in the component area on the second surface layer extends outward, so that the grid copper structure in the bending area at the junction after the first surface layer and the second surface layer are bonded together is a misaligned structure; when the FPC is bent along the bending area in the direction from the component area towards the non-component area, due to the misalignment of the copper laying on the upper first surface layer and the second surface layer, the thickness is reduced by one layer compared with before during bending, and the copper laying on the second surface layer extends a little to increase bending protection, and at the bending area, it is not directly the junction of two layers of grid copper structure and the solid copper structure. In this way, the bending stress is relatively small and the wiring channel will not break. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 is a schematic structural diagram of the first surface layer of the FPC bending structure in the prior art;
[0022] Figure 2 is a schematic structural diagram of the second surface layer of the FPC bending structure in the prior art;
[0023] Figure 3 is a schematic structural diagram of the combined state of the first surface layer and the second surface layer of the FPC bending structure in the prior art;
[0024] Figure 4Schematic diagram of the first surface layer of the improved FPC bending structure in the embodiment of the present utility model;
[0025] Figure 5 Schematic diagram of the second surface layer of the improved FPC bending structure in the embodiment of the present utility model;
[0026] Figure 6 Schematic diagram of the combined state structure of the first surface layer and the second surface layer of the improved FPC bending structure in the embodiment of the present utility model.
[0027] Reference numerals: 1, first surface layer; 2, second surface layer; 3, component area; 31, solid copper structure; 4, non-component area; 41, grid copper structure; 5, routing channel; 6, bending area. Detailed implementation manners
[0028] In the prior art, as Figure 1 and 2 shown, the structures of the first surface layer 1 and the second surface layer 2 are the same, both including a component area 3 and a non-component area 4; a solid copper structure 31 is laid on the component area 3, and a grid copper structure 41 is laid on the non-component area 4; as Figure 3 shown, when the first surface layer 1 and the second surface layer 2 are attached, their solid copper structures 31 and grid copper structures 41 are flush. Therefore, at the junction of the solid copper structure 31 and the grid copper structure 41, that is, the bending area 6, the stress generated during bending is relatively large, resulting in a risk of breakage of the routing channel 5. The present utility model improves the existing structure based on this risk.
[0029] Embodiment 1
[0030] As Figures 4-5 shown, an FPC bending structure proposed by the present utility model includes a first surface layer 1 and a second surface layer 2. Both the first surface layer 1 and the second surface layer 2 include a component area 3 and a non-component area 4; a solid copper structure 31 is laid on the component area 3, and a grid copper structure 41 is laid on the non-component area 4;
[0031] As Figure 6 shown, the component area 3 on the first surface layer 1 shrinks inward, and the component area 3 on the second surface layer 2 extends outward;
[0032] The connection between the component area 3 and the non-component area 4 is the bending area 6; after the first surface layer 1 and the second surface layer 2 are attached together, the bending area 6 maintains a misaligned structure; after the first surface layer 1 and the second surface layer 2 are attached together, the misalignment distance of the bending area 6 is 1 - 2 mm; more preferably, the misalignment distance of the bending area 6 is 1.5 mm; the first surface layer 1 and the second surface layer 2 are attached together, and multiple routing channels 5 are reserved in the middle thereof.
[0033] In this embodiment, when the FPC is bent along the bending area 6 from the component area 3 towards the non-component area 4, due to the misalignment of the copper plating on the upper first surface layer 1 and the second surface layer 2, the thickness is reduced by one layer compared to before during bending. Moreover, the copper plating on the second surface layer extends a little to increase bending protection, so that at the bending area 6, it is not directly the junction of the two-layer grid copper structure 41 and the solid copper structure 31. In this way, the bending stress is relatively small and the wiring channel 5 will not break.
[0034] In this embodiment, the grid copper structure 41 laid on the non-component area 4 is one or a combination of more than one of a diamond grid, a circular grid, a honeycomb grid or a rectangular grid;
[0035] In the present utility model, due to the misaligned structure of the upper and lower surface layers, the thickness of the bending area 6 is reduced by one layer compared to before during bending. Moreover, the copper plating on the lower layer extends a little to increase bending protection, so that at the bending area 6, it is not directly the junction of the two-layer grid and the solid copper. In this way, the bending stress is relatively small and the wiring channel 5 will not break.
[0036] The above has described in detail the embodiments of the present utility model with reference to the accompanying drawings. However, the present utility model is not limited thereto. Various changes can be made without departing from the spirit of the present utility model within the scope of knowledge possessed by those skilled in the art to which the present utility model pertains.
Claims
1. A FPC bending structure, comprising a first surface layer (1) and a second surface layer (2), characterized in that: The first surface layer (1) and the second surface layer (2) both include a component area (3) and a non-component area (4); The component area (3) on the first surface layer (1) shrinks inwards, and the component area (3) on the second surface layer (2) extends outwards; The connection between the component area (3) and the non-component area (4) is a bending area (6); after the first surface layer (1) and the second surface layer (2) are bonded together, the bending area (6) maintains a staggered structure; The first surface layer (1) and the second surface layer (2) are bonded together, with a plurality of wiring channels (5) reserved in the middle.
2. The FPC bending structure according to claim 1, characterized in that: The FPC is bent along the bending area (6) from the component area (3) toward the non-component area (4).
3. The FPC bending structure according to claim 1, characterized in that: A solid copper structure (31) is laid on the component area (3).
4. The FPC bending structure according to claim 1, characterized in that: A grid copper structure (41) is laid on the non-component area (4).
5. The FPC bending structure according to claim 1, characterized in that: After the first surface layer (1) and the second surface layer (2) are bonded together, the offset spacing of the bending area (6) is 1-2 mm.
6. The FPC bending structure according to claim 1, characterized in that: After the first surface layer (1) and the second surface layer (2) are bonded together, the offset spacing of the bending area (6) is 1.5 mm.
7. The FPC bending structure according to claim 1, characterized in that: The grid copper structure (41) laid on the non-component area (4) is a diamond grid.
8. The FPC bending structure according to claim 1, characterized in that: The grid copper structure (41) laid on the non-component area (4) is a circular grid.
9. The FPC bending structure according to claim 1, characterized in that: The mesh copper structure (41) laid on the non-component area (4) is a honeycomb mesh.
10. The FPC bending structure according to claim 1, characterized in that: The grid copper structure (41) laid on the non-component area (4) is a rectangular grid.