Most of the Aluminum PCB are Green. Except Green, we can also see the PCB with Red, Blue, White or even Black color. Why there are multiple colors?
1. The green color is the only one which be used widely on the market till today. It is with long history. And also it is the cheapest one. So many PCB manufacturers used Green as the main color of its products.
2. Generally speaking, the entire PCB product must go through the boarding and SMT process during manufacturing. There are several processes that PCB must pass through the yellow light room. In that room, green board’s effect is better than other colors. But it is not the main reason. When soldering components during SMT process, the PCB must go through the processes of Tin paste, Chip mount and final AOI calibration. All of these need to make optical positioning calibration. If using green color, the equipment’s recognition effect will be better.
3. The common colors for PCB are red, yellow, green, blue and black. However, due to the production process and other issues, many lines’ quality inspection procedures must rely on the workers’ naked eye to observe and identify (Although most of them used flying probe testing technology). Under strong light, the eyes must keep staring at the board. This was a very old work process. Since green is the most eye-friendly color, most manufacturers used it as the main PCB color.
4. The principle for blue and black color is that they are doped with cobalt and carbon lamp elements respectively, which have certain conductive properties. If make the unit Power ON, it is possible to occur the short cut problem. And also because the green ink is environmentally - friendly relatively. There is no toxic gases are released in the high temperature environment for the green ink generally.
There are also less manufacturers will use black PCB on the market. There are two main reasons: Firstly, it looks high-end. Secondly, it is not easy to see the wiring on the black board, which brings certain difficulty for copying the board. As we know, most Android embedded boards are using black PCBs.
5. Many LED panels used white PCB. Because white can reflect light and with low absorption of heat.
According to the different usage and customer’s requirements, there are multiple colors for PCB.