Routing layout method and wiring layout structure in bending area of ​​flexible printed circuit board

Abstract

The invention discloses a trace layout method for a bending area of a flexible printed circuit board and a trace layout structure. The trace layout method comprises the steps as follows: a substrate of the flexible printed circuit board is provided and the bending area is defined on the substrate of the flexible printed circuit board; the bending area has a layout width threshold; traces are laid on the substrate; whether the widths of the traces are greater than the layout width threshold or not is judged; and the parts, in the bending area, of the traces of which the widths are greater than the layout width threshold are separated into a plurality of branch lines for layout. The layout width of the traces in the bending area are defined by setting the layout width threshold of the traces in the bending area of the substrate of the flexible printed circuit board, so that the problem that bending is relatively difficult since the layout width of the traces in the bending area is relatively large is solved; the improved flexible printed circuit board is convenient to bend; the operation is simplified; and the production efficiency of the flexible printed circuit board is improved.

Description

technical field [0001] The invention relates to flexible printed circuit board technology, in particular to a routing method and routing structure for a bending area of ​​a flexible printed circuit board that needs to be bent. Background technique [0002] Flexible printed circuit board (FPC, Flexible Printed Circuit) is a kind of flexible circuit board using polyimide (PI) or polyester film as the base material. Compared with ordinary printed circuit boards (PCB, Printed Circuit Board), FPC has the characteristics of high wiring density, light weight, thin thickness, good bendability, easy three-dimensional assembly after folding, and can withstand multiple dynamic bending movements. Due to the advantages of FPC itself, it has been widely used in consumer electronic products such as mobile phones, notebook computers, and PADs in the past ten years. FPC is generally connected with PCB to realize electrical functions. [0003] At present, in mobile phones, most of them use ...

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Problems solved by technology

[0004] Due to the limitation of installation space, the bending area of ​​FPC is very short. If the design of the bending area is unreasonable, the stress will be large, and it will easily rebound, which will lift up the PCB of the module, affecting the compactness of the LCM structure, and it is not easy to operate. It may even lead to difficulty in assembly due to the unevenness of the bending area, affecting the use function and manufacturing yield

[0005] refer to figure 1 As shown, in the bending area 21 of the FPC, there are power lines 22 with a larger width and signal lines 23 with a smaller width passing through at the same time. Due to the copper width of the line part with a larger width, the hardness of the power line 22 is relatively high. large, it is difficult to bend; and the copper in the line part with a smaller width is thinner, so the signal line 23 is softer and easier to bend, which is not only inconvenient to bend the FPC, but also leads to The overall line is bent unevenly, which affects the assembly of FPC

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