A PCB (Printed Circuit Board) mainly consists of a substrate, copper foil, circuit patterns, and solder mask. The substrate is the basic structure of the PCB; common materials include FR-4 fiberglass board, aluminum substrate, and flexible PI material. Different materials affect the PCB's heat resistance, mechanical strength, and electrical performance. Copper foil is responsible for current and signal transmission, forming various conductors, power lines, and grounding networks through etching processes, and is the core for interconnecting electronic components. For high-frequency and high-speed products, higher requirements are placed on copper thickness, line width, and dielectric constant to ensure signal stability and anti-interference capabilities.
The solder mask and silkscreen layer on the PCB surface are equally important. The solder mask is usually green ink, but can also be black, white, red, etc. Its function is to prevent short circuits, oxidation, and environmental corrosion during soldering, while also improving the insulation performance of the circuit board. The silkscreen layer is mainly used to identify component numbers, polarity, interface locations, and production information, facilitating later assembly, testing, and repair. In addition to surface treatments, PCBs undergo surface treatments such as tin plating, immersion gold plating, and OSP (Optical Separation Process) to improve soldering reliability and oxidation resistance. Different processes directly impact product lifespan and manufacturing costs.
Within the internal structure of PCBs, multilayer board design is also a crucial component of modern electronic products. As electronic devices continue to evolve towards miniaturization and high performance, single-layer boards are no longer sufficient to meet the demands of complex circuits. Therefore, many products utilize 4-layer, 6-layer, or even higher-layer PCB structures. Multilayer PCBs, through the rational stacking of inner power, ground, and signal layers, not only increase wiring density but also effectively reduce electromagnetic interference, improving signal integrity and system stability. Especially in fields such as communication equipment, industrial control, automotive electronics, and servers, high-layer PCBs have become a key foundation for enhancing product performance and reliability.
