The minimum radius of the inner corner on the flexible profile is 1.6 mm. The larger the radius, the higher the reliability and the stronger the tear resistance. In the corners of the shape, you can add a line near the edge of the board to prevent the flexible PCB from being torn.
The cracks or grooves on the flexible PCB must end with a round hole with a diameter of not less than 1.5 mm, which is also necessary when two adjacent parts of the FPC need to be moved separately.
In order to obtain better flexibility, it is necessary to select the bending area in a uniform width area, and as far as possible the flexible PCB width change and the uneven trace density in the bending area.
Stiffener is mainly used to obtain external support. The materials used include PI, polyester, glass fiber, polymer materials, aluminum, steel, etc. Reasonable design of the position, area and material of the reinforcement board has a great effect on avoiding flexible PCB tearing.
In the multi-layer flexible PCB design, the air gap layered design needs to be carried out in the area that is often bent during the use of the product. Try to use thin PI material to increase the softness of the flexible PCB and prevent the flexible PCB from cracking during repeated bending.
When space permits, a double-sided tape fixing area should be designed at the joint between the golden finger and the connector to prevent the golden finger and the connector from falling off during the bending process.
The flexible PCB positioning screen should be designed at the connection between the flexible PCB and the connector to prevent the flexible PCB from skewing during the assembly process.