Flexible and Reliable Design of Flexible Circuit Board During Factory Processing (Part 2)

Although it is expected that flexible printed circuits can meet all applications that require bending, bending and some special circuits, in these applications, a large part of bending or bending fails. Flexible materials are used in the manufacture of printed circuit boards, but the flexible materials themselves cannot guarantee the reliability of the circuit function when being bent or bent, especially in dynamic applications. Many factors can improve the reliability of the molding or repeated bending of the printed flexible printed circuit board. In order to ensure the reliable operation of the finished circuit, all these factors must be considered during the design process. Here are some tips for increasing flexibility:

1) In order to improve dynamic flexibility, circuits with two or more layers should choose electroplated boards. 　　

2) It is recommended to keep the number of bends to a minimum. 　　

3) The wires should be arranged staggered to avoid the I-type micro-beam effect, and the wire paths should be orthogonal to facilitate bending. 　　

4) In the bent area, do not place pads or through holes. 　　

5) Do not place ceramic devices near any bending area to avoid discontinuous coating, discontinuous plating or other stress concentrations. It should be ensured that there are no distortions in the finished assembly. Twisting may cause undesirable stress on the outer edge of the circuit. Any burrs or irregularities in the blanking process may cause the circuit board to crack. 　　

6) Factory forming processing should be the first choice. 　　

7) In the bending area, the thickness and width of the conductor should remain unchanged. There should be changes in plating or other coatings to avoid neck-like shrinkage of the wires.

8) Make a long and narrow cut in the flexible printed circuit, allowing different wooden brackets to bend in different directions. Although this is an effective means to maximize efficiency, it is easy to cause tearing and extension of the slit at the incision. This problem can be prevented by making a hole at the end of the incision, using a rigid plate or a thick flexible material or PTFE Ethylene is used to reinforce these areas (Finstad, 2001). Another method is to make the incision as wide as possible and make a complete semicircle at the end of the incision. If it cannot be reinforced, the circuit cannot be bent at a distance of 1I2in from the end of the cut.