FPC flex, also known as flexible circuit boards or flexible printed circuit boards, is favored for its excellent characteristics such as light weight, thin thickness, and the ability to bend and fold freely... However, domestic quality inspection of FPC still mainly relies on manual visual inspection, which is costly and inefficient. With the rapid development of the electronics industry, circuit board designs are becoming increasingly high-precision and high-density, and traditional manual inspection methods can no longer meet production demands. Automated defect detection of FPC has become an inevitable trend in industry development.

Flexible Printed Circuit (FPC) is a technology developed in the United States in the 1970s for the advancement of aerospace rocket technology. It is a highly reliable, flexible printed circuit made of polyester film or polyimide as the substrate. By embedding circuit designs on thin, bendable plastic sheets, it allows a large number of precise components to be stacked in narrow and limited spaces, forming a flexible circuit. This type of circuit can be bent and folded freely, is lightweight, compact, has good heat dissipation, and is easy to install, breaking through traditional interconnection technology. In the structure of a flexible circuit, the materials that make it up are insulating film, conductor, and adhesive.