PCB (printed circuit board) is a printed circuit board, abbreviated as printed circuit board, which is one of the important parts of the electronics industry. Almost every kind of electronic equipment, from electronic watches, calculators, to computers, communication electronic equipment, military weapon systems, as long as there are electronic components such as integrated circuits, in order to make the electrical interconnection between the various components must be printed board. The printed circuit board is composed of an insulating bottom plate, connecting wires and pads for assembling and welding electronic components, and has the dual functions of conductive lines and insulating bottom plates. It can replace complex wiring and realize the electrical connection between the components in the circuit, which not only simplifies the assembly and welding of electronic products, reduces the workload of traditional wiring, and greatly reduces the labor intensity of workers; it also reduces the overall machine Volume, reduce product cost, and improve the quality and reliability of electronic equipment. The printed circuit board has good product consistency, and it can adopt standardized design, which is conducive to the realization of mechanization and automation in the production process. At the same time, the entire printed circuit board that has been assembled and debugged can be used as an independent spare part to facilitate the interchange and maintenance of the entire product. At present, printed circuit boards have been extremely widely used in the manufacturing of electronic products.

The earliest printed circuit boards used paper-based copper-clad printed boards. Since the emergence of Semiconductor transistors in the 1950s, the demand for printed boards has risen sharply. In particular, the rapid development and wide application of integrated circuits have made the volume of electronic equipment smaller and smaller, and the density and difficulty of circuit wiring have become greater and greater, which requires continuous updating of printed boards. At present, the variety of printed boards has developed from single-sided boards to double-sided boards, multilayer boards and flexible boards; structure and quality have also developed to ultra-high density, miniaturization and high reliability; new design methods, design supplies and Board-making materials and board-making techniques continue to emerge. In recent years, various computer-aided design (CAD) printed circuit board application software has been popularized and promoted in the industry. Among specialized printed board manufacturers, mechanized and automated production has completely replaced manual operations.