Why do PCB boards have multiple colors? Are there any rules

Why do PCB boards have multiple colors? Are there any rules

Most of the PCBs we can see every day are green, but in addition to green, we can occasionally see blue, even black PCBs. Why do PCB boards choose different colors? Why is green the most common color? This article will reveal the secret behind the "colorful" PCB.

Green ink is by far the most widely used, the longest history, and the cheapest in the current market, so green is used by a large number of manufacturers as the main color of their products.

In general, the whole PCB product must go through the process of board making, SMT, etc. in the manufacturing process. When making boards, there are several processes that must go through the yellow light room, and the effect of green in the yellow light room is better than that of other colors. But this is not the main reason. When SMT is welding components, PCB needs to go through the process of solder paste and paste and the final AOI calibration lamp. These processes all need optical positioning calibration. The green background has a better recognition effect on the instrument.

Common PCB colors are red, yellow, green, blue and black. However, due to the manufacturing process and other problems, the quality inspection process of many lines must still rely on the visual observation and identification of workers or the use of flying probe testing technology. In the case of strong light, green is relatively harmless to the eyes, so most manufacturers on the market use green PCB.

The principle of blue and black is that they are doped with cobalt, carbon and other elements respectively, which have certain conductivity, and the problem of short circuit is likely to occur when the power is on. In addition, green PCBs are relatively environmentally friendly, and generally do not release toxic gases when used in high temperature environments.

On the other hand, a small number of manufacturers in the market will use black PCB boards. The main reason may be that black boards look more "tall", but it is not easy to see the wiring in black boards, which brings some difficulties to copy boards. Most of the embedded Android boards now use black PCBs.

In fact, since the middle and late last century, the industry has begun to pay attention to the color of PCB. This is mainly because many high-end board types of first-line large factories have adopted the green PCB color design, so people gradually believe that green is the "default" color of PCB.

The choice of PCB color is the epitome of the rise, development and choice of a new technology in the development of modern science and technology. While the birth and development of PCB has promoted the process of countless electronic industries, it is also constantly evolving and changing. In the near future, PCB of other colors may replace the current trend of green, let's wait and see!

PCB manufacturers, PCB designers and PCBA manufacturers explain why PCB boards have multiple colors.