We often see PCB circuit boards, and we will find that there are many colors. In fact, these colors are made by printing different PCB solder mask inks. Whether it is a circuit board on an electrical appliance, a mobile phone motherboard or a computer motherboard, PCB circuit boards are used.

Common colors in PCB solder mask inks are green, black, red, blue, white, yellow, etc. Many people are curious, what is the difference between these different colored circuit boards?

01Green solder mask ink has the longest history, the cheapest and the most popular.

02 Generally speaking, the entire electronic board-level products have to go through the board making and patching process. There are several processes in the board making process that have to pass through the yellow light room. The visual effect of green in the yellow light room is better, but this Not the main one. During SMT welding, it is necessary to pass the tinning and patching and the final AOI verification. These processes all need to be calibrated by optical positioning. The green background color is better for the identification of the instrument.

03 The common ones are red, yellow, green, blue and black. Because of process problems, the inspection of many lines still relies on workers to see with their eyes (of course, most of them are now tested by flying probes). Constantly looking at the board with bright eyes, this is a very tiring job, and green is relatively harmless to the eyes. So most of them choose green.

PCB circuit board

04 The blue and black colors are because they are doped with cobalt and carbon, respectively, and have a certain degree of conductivity, so there is a risk of short circuit. The green PCB is more environmentally friendly and will not release toxic gases when used in a high temperature environment.

05 All the above are talking about the advantages of green solder mask ink. In fact, other color inks are not useless.