Printed Circuit Board (PCB) refers to an assembly board that selectively processes mounting holes, connecting wires, and solder pads for assembling electronic components on an insulating substrate to achieve electrical interconnection between electronic components. Due to its ability to achieve electrical connections between various components in a circuit, almost any electronic device cannot do without it. It plays an important role in the electrical performance, mechanical strength, and reliability of the circuit, and is therefore known as the "mother of electronic products".

According to Prismark data, the global PCB output value in 2023 decreased by 14.9% year-on-year, reaching a scale of 69.5 billion US dollars. Prismark predicts that the global PCB output value will return to growth in 2024, reaching 73.026 billion US dollars, a year-on-year increase of 5%.

Upstream and downstream of PCB and product classification

The upstream of the PCB industry chain includes electronic fiberglass yarn, copper, wood pulp, epoxy resin, etc. The direct cost accounts for nearly 60% of the cost structure of PCB, so it is greatly affected by fluctuations in raw material prices. The downstream of the PCB industry chain covers many fields, including computers, communication equipment, consumer electronics, automotive electronics, industrial control, medical instruments, military aerospace, etc. There are many types of printed circuit boards, which can be divided into rigid boards, flexible boards, rigid flex combination boards, and packaging substrates based on product structure and characteristics. And special products such as metal substrates and high-frequency high-speed boards.

Line width/spacing, HDI and SLP

HDI (High Density Interconnect), also known as high-density interconnect board, has the advantages of being lightweight, having high line density, facilitating the use of advanced construction technologies, better electrical characteristics and signals, improving radio frequency interference/electromagnetic wave interference/electrostatic discharge, and having short transmission paths. Therefore, it has been widely used in fields such as 3C, medical equipment, and communication equipment. It utilizes laser drilling technology, breaking the limitations of traditional mechanical drilling, which is a major feature of HDI technology. The mechanical drilling of traditional PCBs is affected by the drilling tool, and when the aperture reaches 0.15mm, the cost significantly increases and it is difficult to further improve. The minimum line width/spacing of HDI board is 75/75 µ m or less, the minimum via hole diameter is 150 µ m or less, it contains blind holes or buried holes, the minimum pad size is 400 µ m or less, and the pad density is greater than 20/cm2.