PCB (printed circuit board) is printed circuit board, or printed circuit board for short, which is one of the important components in the electronics industry. Almost every kind of electronic equipment, 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, we must use printed board. The printed circuit board is composed of an insulating bottom plate, connecting wires and pads for assembling and soldering electronic components, and has the dual functions of a conductive line and an insulating bottom plate. It can replace the complicated 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 wiring workload in the traditional way, greatly reduces the labor intensity of workers; and reduces the overall machine Volume, reduce product cost, improve the quality and reliability of electronic equipment. The printed circuit board has good product consistency, it can adopt standardized design, which is conducive to mechanization and automation in the production process. At the same time, the entire printed circuit board after assembly and debugging can be used as an independent spare part, which is convenient for the exchange and maintenance of the whole product. At present, printed circuit boards have been extremely widely used in the manufacture of electronic products.

Printed circuit boards were first used on 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 make the volume of electronic equipment smaller and smaller, and the circuit wiring density and difficulty more and more difficult, which requires the printed board to be constantly updated. At present, the variety of printed boards has developed from single-sided to double-sided, multi-layered and flexible boards; the structure and quality have also been developed to ultra-high density, miniaturization and high reliability; new design methods, design supplies and Plate-making materials and plate-making technology are constantly emerging. In recent years, various computer-aided design (CAD) printed circuit board application software has been popularized and promoted in the industry. Among the specialized printed board manufacturers, mechanized and automated production have completely replaced manual operations.