PCB Technical - The visual effect of the green PCB chip substrate

PCB patch processing is more popular and common in the electronics industry. PCB boards have a certain color. The color is actually the color of solder resist. Solder resist is more important in PCB patch processing. It can prevent components. Incorrect soldering can also delay the service life of the device and make the device and the circuit less prone to oxidation or corrosion. But generally speaking, the color of PCB board is mainly green. Why are most of them green? What are the advantages?

This is mainly because the green solder mask process is the most mature and simple, and the green board is also more environmentally friendly. In addition to green, PCB boards have white, yellow, red, blue, matte colors, and even chrysanthemum, purple, black, bright green,

etc. White exists because it is a color that must be used to make lamps and lanterns, and the use of other colors is mostly to distinguish different product samples. During the entire stage of the company from R&D to product landing, depending on the different uses of the PCB, the experiment board may be purple, the key board will be red, and the internal boards of the computer will be black, and they are distinguished and marked by color. As for green oil, its solder mask ink has a long history, is cheap and popular, and has many advantages:

1. In PCB processing, the production of electronic products includes board making and post filming. During the process, there are several processes to go through the yellow light room, and the visual effect of the green PCB board in the yellow light room is better;

2. Secondly, during SMT patch processing, the steps of tinning, patching and AOI verification all require optical positioning calibration, and the green bottom plate is more friendly when it is recognized by the instrument;

3. Part of the inspection process relies on worker observation (but now most of them use flying probe testing instead of labor), staring at the board under strong light, green is friendly to eyes;

4. Green PCBs are also relatively environmentally friendly. When the waste boards are recycled at high temperature, they will not release toxic gases. Other PCB colors, such as blue and black, are doped with cobalt and carbon, respectively, because they have weak electrical conductivity, and there is a risk of short circuit. In addition, like black, purple, and blue lights, the color of the PCB substrate is too dark, which will increase the difficulty of the inspection and maintenance of the motherboard, and the process is not easy to control.

Taking the black board as an example, the black board is easier to produce due to process and raw material ratio problems. A little carelessness will cause obvious chromatic aberration and result in a high PCB defect rate. The traces of the black circuit board are not easy to distinguish, which will increase the difficulty of post-maintenance and debugging. Many PCB factories do not use black PCB very much. Even in the fields of military industry and industrial control, products with extremely high quality requirements are mainly made of green PCB substrates. The color of the PCB board does not affect its performance in the slightest.

The green color of the PCB board of the PCB patch can indeed bring a lot of benefits, but in fact, the color of the PCB board has no direct effect on its performance. The use of green is only because the color of green is better in the yellow room during processing. Secondly, when performing optical positioning and calibration, green is also more friendly to the recognition of the instrument. Moreover, green is eye-friendly and marked as environmentally friendly. Green PCB boards can bring a lot of convenience to processing. Over time, green PCB boards occupy the market. Most of them have become more common colors.