PCBA Tech - Why are most PCB boards green?

Is there such a situation that causes people to be very confused about it? Most of the PCB boards you can see are green, but other color PCB boards are rare. So why is that? Others say that black PCB boards represent high-end visual colors, is that true?

Today, the Shenzhen IPCB will give you a general explanation of the definition of these PCB circuit boards color. Next, SMT technical engineer will take you to understand this green PCB circuit board.

Printed circuit boards (PCBs) usually consist of bonding pads, holes, solder layers, screen printing layers, copper wires, various components, etc. Among them, solder mask refers to the green oil on printed PCB circuit boards. In fact, the solder-resistant ink is not only green, but also red, yellow, blue, purple, black and so on. But green solder-resistant ink is the most common ink.

Function of the welding resistance layer:

(1) Prevent physical disconnection of PCB circuit board conductor circuit;

(2) Prevent short-circuit caused by bridge connection in PCB circuit board welding process;

(3) Only weld part of the PCB circuit board that must be welded to avoid waste of solder;

(4) Reduce the copper pollution to the weld slot of PCB circuit board;

(5) Prevent deterioration and corrosion of PCB circuit board insulation caused by external environmental factors such as dust and moisture;

(6) High insulation makes it possible to densify PCB circuit boards.

Why are PCB circuit boards mostly green? The main reasons are as follows:

1. Green irritates the eyes little. Everyone knows that green is good for eyes, protects them and resists fatigue. It is not easy for production and maintenance personnel to fatigue their eyes and do less damage to them when they focus on PCB circuit boards for a long time.

2. Low cost, because green is the mainstream in the process of PCB circuit board production, the purchase amount of natural green paint will be larger, and the purchase cost of green paint will be lower than other colors; At the same time, using the same color paint in mass production can also reduce the cost of switching lines.

3. When PCB circuit board is welded in SMT technology shop, it needs tin and patch and final AOI check. These processes need optical positioning calibration, and green background color will be better to identify the instrument.

Are black PCB boards more advanced?

Probably since 2007, people began to notice the color of PCB PCB boards. This is mainly because the high-end boards of Asus and Weixin first-line factories all use black PCB board color design, so people slowly think that black PCB boards must be high-end, but in fact, this recognition is incorrect.

The difference between the black PCB board and the green PCB board, the blue PCB board, the Yellow PCB board and other color PCB boards is that the color of the solder resistance ink on the last brush is different. If the PCB circuit board is designed and manufactured in the same way, the color will not have any effect on the performance, nor will it have any effect on the heat loss.

With regard to black PCB boards, because their surface wiring is almost completely obscured, which causes great difficulties for later maintenance operations, it is not a convenient color to manufacture and use, and black PCB boards are the most difficult for holes, so the good product rate is relatively lower than other color PCB boards. So black is relatively expensive.

The reason why the term "color represents high or low grade" appears is that manufacturers like to use black PCB circuit boards to make high-end products, and red, blue, green, yellow and other low-end products. To sum up, a product gives meaning to its color, not to its color.

Whether it is a black PCB board or a green PCB board, the PCB board with good performance and heat dissipation is of high quality.