What are the effects of copper thickness on PCB circuit boards?

　　In the PCB manufacturing process, errors are inevitable, but their tolerance range must strictly follow industry standards. Once it exceeds the standard tolerance range, it will directly affect the performance and reliability of the product. According to the IPC standard, the error range of PCB production mainly includes line width/line spacing tolerance, drilling position accuracy, interlayer alignment deviation, and surface treatment thickness. This article will analyze in detail the standard range, influencing factors, and control methods of these types of errors.

　　1、 Standard error range:

　　Firstly, there is the line width/line spacing tolerance. The line width error of ordinary boards is usually around ± 20%, and the minimum line width will also be controlled at ≥ 0.1mm. However, the line width/line spacing tolerance range of high-precision boards is around ± 10%, and the minimum line width can reach 0.05mm.

The second is the accuracy error of drilling position. The error range corresponding to different drilling methods is also different. The error range of mechanical drilling is ± 0.05mm, while the accuracy error range of laser drilling (HDI board) is ± 0.025mm;

　　In addition, there is also interlayer alignment deviation. Generally speaking, the alignment deviation range for 4-layer boards is ± 0.075mm, while for 8-layer and multi-layer boards it is ± 0.05mm. The error in surface treatment thickness also varies depending on the process, with the standard thickness error for gold deposition ranging from 0.05 to 0.15 μ m and the standard thickness error for tin plating ranging from 3 to 8 μ m.

　　2、 Reasons for errors and control methods:

　　The main reasons for errors include board characteristics, equipment accuracy, and human factors. When producing PCBs, if the selected board is not suitable, the equipment accuracy is insufficient, or the operator does not accurately calculate when calibrating the equipment, it will lead to the expansion of errors and cause quality problems. The range of errors can be effectively controlled through material selection optimization, equipment upgrading, and personnel training.