As is known to all, printed circuit board plays a very important role in People's Daily life, and has been widely used in industrial production, national defense security and medical and health fields. The traditional PCB preparation process is very complicated, which needs to go through more than a dozen processes. In recent years, flexible electronics has become increasingly popular. Unlike traditional rigid circuit boards, flexible circuit boards can be bent, folded or even stretched at will, which makes them of great value in wearable devices, portable medical devices, skin electronics and other fields.