Why are most PCB boards green?

Green color is solder mask ink, which is mainly composed of resin, talc powder and pigment. At present, the most famous ones in the market are Taiyo from Japan, Nanya resin from Taiwan, Changxing chemical industry from Taiwan and yongshengtai ink from Taiwan. The price is generally 60 ~ 120 yuan / kg. Of course, there are other colors, such as red, yellow, black, etc., green is the most widely used.

On this question (why are most circuit boards green?) The answer is as follows:

Point of view 1, generally speaking, the whole electronic board level products have to go through the process of making boards and pasting. In the process of making boards, there are several processes that need to go through the yellow light room. The visual effect of green in the yellow light room is better, but this is not the main one.

In SMT welding, tin and paste and final AOI verification should be carried out. These processes need optical positioning calibration. The green background color is better for the identification effect of the instrument.

Point 2. The common ones are red, yellow, green, blue and black. Due to the technical problems, the inspection of many lines still depends on the workers' eyes (of course, most of them use flying needle test now). It's a very tiring job to keep looking at the board with strong light eyes. Green is relatively the least harmful to the eyes

So most of them are green.

Viewpoint 3. Blue and black are respectively doped with cobalt and carbon, which have certain conductivity, so there is a risk of short circuit. Green PCB is more environmentally friendly and will not release toxic gases when used in high temperature environment.

Viewpoint 4. From about 2007, people began to pay attention to the color of PCB board. The main reason is that ASUS MICROSTAR has adopted the black PCB board color design for high-end boards. Therefore, people gradually think that if the color of PCB is black, it must be high-end. After that, more and more manufacturers began to use black PCB coating - it can be said that there is an inexplicable reason for this phenomenon. No one has ever said that the PCB color is black, which means the quality of the motherboard must be good. This is completely due to the misleading of the first-line brands using black to identify product positioning. It is true that black PCB is able to show its own technical strength, because black PCB is the most difficult to see the wiring, so both design and after-sales will suffer unprecedented cost pressure, and the board manufacturers with strong technical strength do not use black PCB color to improve the performance of motherboard. From the perspective of rational analysis, it is also known that color alone can not It may improve the performance of the board.

Point of view 5. There is no reason, but it has been used all the time