The Printed Circuit Board (PCB) is one of the main parts of all electronic products. The application fields of PCB are quite extensive. Wherever electronic components are used, PCBs are almost always used. Currently, they are mainly used in the fields of information, communication, consumer products, automobiles, aerospace and military, precision instruments and industrial products. They are an indispensable basic part of all electronic products. This article will be divided into several aspects to discuss PCBs, namely type, material, process, installation and welding. Let us have a good understanding of the "mother of the electronics industry" – the PCB.