In fact, fans have been learning circuit may all have this question, and that is why we use the vast majority of the board is green? Actually, PCB is not necessarily green, depending on the designer wants to make it What color is that it is what color.
Usually we use the green, because green eye irritation, production and maintenance personnel in a long time staring at the PCB industry is not easy to do damage to the eyes small eye fatigue. There are common color, yellow, black, red. Various colors are manufactured on the surface after a good spray paint.
There is a reason, because we used color is green, so green paint factory spare is the largest, so the relatively low cost of oil. And because of the maintenance of the PCB when different wiring easier to tell the difference between white and black and white is relatively difficult to see. Each plant in order to differentiate their products grade, is to use two colors to distinguish between high-end and low-end series series. Such as making the computer motherboard companies Asustek, yellow plate is low-end, high-end board. Biostar backboard is high-end, low-end green board.
At present, only black PCB costs will be higher than other colors PCB, but not to say that black PCB electrical performance better, but in production, the black hole of the PCB highest degree of difficulty, and therefore yield relatively than other colors PCB board to be lower.