Printed circuit boards are one of the important electronic components in the electronic industry. Almost every electronic device, from electronic watches, calculators, computers, communication electronic devices, military weapon systems, as long as there are integrated circuits and other electronic components, in order to interconnect them, printed circuit boards are used. The most basic success factor is the design of PCB and the PCB production of documents. The manufacturing quality of PCB design directly affects the cost of the whole product quality, and even leads to the success or failure of a company.

The ratio of output value of PCB to output value of electronic equipment is called input coefficient of PCB. It was 2-3% in the 1970s and increased to 6-7% in the 1990s. This also shows the position of PCB in electronic equipment.

Printed circuit has the following functions in electronic equipment:

Provide mechanical support for fixing and assembling various electronic components such as integrated circuits.

Realize wiring and electrical connection or electrical insulation between various electronic components such as integrated circuits. Provide required electrical characteristics, such as characteristic impedance.

Provide solder resistance graphics for automatic soldering and recognition characters and graphics for component assembly, inspection and maintenance.

Because of the consistency of the same kind of PCB used in electronic equipment, the error of manual wiring can be avoided, and electronic components can be automatically inserted or mounted, tin-welded and inspected. The quality of electronic equipment can be guaranteed, labor productivity can be improved, cost can be reduced, and maintenance can be facilitated.

PCB develops from one-sided to two-sided, multi-layer and flexible, and maintains its own development trend. As PCB develops towards high precision, high density and high reliability, it reduces volume, reduces cost and improves performance continuously, which makes PCB still maintain strong vitality in the development of electronic equipment in the future.