The PCB industry continues to develop, mainly due to the strength of two aspects. First, the market space of the circuit board industry application industry continues to expand, the communication industry and the automotive industry, and the application of the industrial control industry have been improved, making the high-end multi-layer PCB market grow very rapidly, and the current application ratio reaches 50%. At the same time, the proportion of digital circuit boards in color televisions, mobile phones and automotive electronics has also increased significantly, thus expanding the space of the circuit board industry.
A multi-layer PCB board is a circuit board composed of three or more layers of conductive graphics and insulating material intervals, and the conductive graphics between them are connected to each other as required. Multilayer PCB circuit board is the product of the development of electronic information technology to high-speed, multi-function, large capacity, small volume, thin and light direction. According to the characteristics, the circuit board can be divided into metal circuit board, FR-4 glass fiber board and soft and hard combined board.
China's research on circuit board automatic detection system also began in the early 1990s, there are few research institutions engaged in this research, due to the influence of various factors, the research on PCB defects automatic optical detection system also stays at a relatively primary level. It is precisely because the PCB automatic inspection system is too expensive in foreign countries, the real PCB automatic inspection equipment has not been developed in China, so most of the domestic PCB manufacturers still use magnifying glass or projector manual inspection method. Due to the labor intensity of manual inspection, eyes are easy to fatigue, and the rate of missed detection is high. Moreover, with the development of electronic products in the direction of miniaturization and digitalization, printed circuit boards are also developing in the direction of high density and high precision, which is difficult to achieve by manual detection. For boards with higher density and higher precision (0.12~0.10mm), it is completely impossible to check. Due to backward detection methods, the pass rate of domestic multi-layer boards (8-12 layers) is only 50-60%. It also increases a lot of costs. Especially some difficult boards.
The PCB circuit board determines the process difficulty and processing price according to the number of wiring surfaces. Ordinary PCB circuit boards are divided into single-sided wiring and double-sided wiring, commonly known as single panel and double panel. However, for high-end electronic products, due to the limitations of product space design factors, in addition to the surface wiring, the internal can also be stacked multi-layer circuits, thus giving birth to the multi-layer PCB board, in the production process, each layer of the line is completed, through the optical device positioning and pressing, so that the multi-layer line can be stacked on a PCB board. Commonly known as multi-layer PCB circuit board. Any circuit board that is greater than or equal to 2 layers can be called a multilayer circuit board. Multi-layer PCB board can be divided into multi-layer hard board board, multi-layer soft board and multi-layer hard and soft combined circuit board.