PCB (printed circuit board) is a printed circuit board, referred to as a printed circuit board, and is one of the important components of the electronics industry. Almost every electronic device, ranging from electronic watches and calculators to computers, communication electronic equipment, and military weapon systems, as long as there are electronic components such as integrated circuits, in order to make the electrical interconnection between various components, use printed circuit boards. plate. The printed circuit board consists of an insulating base plate, connecting wires, and pads for assembling and soldering electronic components, and has the dual functions of a conductive circuit and an insulating base plate. It can replace complex wiring and realize the electrical connection between components in the circuit, which not only simplifies the assembly and welding of electronic products, reduces the workload of wiring in the traditional way, and greatly reduces the labor intensity of workers; it also reduces the size of the whole machine. volume, reduce product costs and improve the quality and reliability of electronic equipment.