PCB is the abbreviation of Printed Circuit Board, translated into Chinese is called printed circuit board, because it is made by electronic printing, it is called "printed circuit board". PCB is an important electronic component in the electronics industry, a support for electronic components, and a carrier for electrical connection of electronic components. PCB has been extremely widely used in the manufacturing of electronic products. The unique characteristics of PCBs are summarized as follows: 　　1. High wiring density, small size and light weight, which is conducive to the miniaturization of electronic equipment.　　2. Because the graphics are repeatable and consistent, errors in wiring and assembly are reduced, and equipment maintenance, debugging and inspection time are saved.　　3. It is conducive to mechanization and automated production, which improves labor productivity and reduces the cost of electronic equipment.　　 4. The design can be standardized, which facilitates interchangeability.