Flexible printed circuit (FPC) is a technology developed by theUnited Statesto develop aerospace rocket technology in the 1970s. It is high reliability, excellent deflection made by polyester film or polyimide as a substrate material. A flexible circuit is formed by embedding a circuit design in a thin, flexible plastic sheet that is flexible, allowing a large number of precision components to be stacked in a narrow and limited space. This circuit can be bent and folded at will. Flexible has the characteristics like light weight, small size, good heat dissipation, easy installation, etc, it breaks through the traditional interconnection technology in the structure of the flexible circuit, the material is composed of insulating film conductor and adhesive