PCB board surface color, is actually the color of solder. First, the solder inhibitor can prevent the occurrence of component miswelding. Second, it can delay the service life of the device and prevent the oxidation and corrosion of the device circuit. If you know more about electronic products, you will find that PCB color is generally green. This is mainly because the green resistance welding process is the most mature, simple, green board is more environmentally friendly. In addition to green, PCB board and white, yellow, red, blue, sub-light, and even chrysanthemum, purple, black, bright green. White exists because it is the color material that must be used for making lamps and lanterns, and the use of other colors is more so as to distinguish different product samples. The company from R & D to product landing throughout the stage, according to the different uses of PCB board, the experimental board may be purple, the key board will have red, the computer interior board will use black, through the color to distinguish mark.
As for green oil, its solder resist ink is the oldest, cheapest and most popular. There are many advantages:
1. In pcb processing, the production of electronic products includes board making and patch making, during which several processes have to go through the yellow room, and the green PCB board has the best visual effect in the yellow room;
2. In SMT chip processing, the steps of soldering, chip mounting and AOI calibration all need optical positioning calibration, and the green backplane instrument is more friendly in identification;
3. Some inspection procedures rely on workers' observation (but now most of them use flying needle test instead of manual work), keep staring at the board under strong light, and green is friendly to eyes;
4. The green PCB is relatively environmentally friendly, and when the waste board is recycled at high temperature, it will not release toxic gas. Other PCB colors, such as blue and black, are doped with cobalt and carbon, respectively. Because of weak conductivity, there is a risk of short circuit. In addition, like black, purple and blue lights, the PCB substrate is too dark, which will increase the difficulty of inspection and maintenance of the motherboard, and the process is not easy to control. Take the black board as an example, the black board is most likely to suffer from the problems of process and raw material ratio in production, and a little carelessness will cause obvious color difference, which will lead to high defective rate of PCB. The wiring of black PCB is not easy to distinguish, which will increase the difficulty for later maintenance and debugging. Many PCB factories don't use black PCB very much. Even in the field of military industry and industrial control, products with extremely high quality requirements are mainly made of green PCB substrates. PCB color does not affect its performance at all.
