PCB Blog - What is the reason why most PCB boards are green

I wonder if you have noticed a situation where most PCB board are green, while circuit boards with other colors are relatively rare. Why is this? Others say that black PCB boards represent high-end products. Is this really the case? Printed circuit boards are usually composed of solder pads, vias, solder resist layers, silk screen layers, copper wires, various components, and other components. The solder resist layer refers to the part of the printed circuit board that needs to be coated with green oil. In fact, solder resist inks are not only green, but also red, yellow, blue, purple, black, etc., but green is the most common.

black pcb board

The function of the solder mask layer:

1) Prevent physical disconnection of conductor circuits;

2) During the welding process, prevent short circuits caused by bridge connection;

3) Only weld the parts that must be welded to avoid waste of solder;

4) Reduce copper pollution to the welding material tank;

5) Prevent insulation deterioration and corrosion caused by external environmental factors such as dust and moisture;

6) High insulation makes it possible to achieve high density of circuits.

Why are most PCB board green? The main reasons are as follows:

1. Green has little irritation to the eyes. Since childhood, our teacher has told us that green is good for our eyes, protects them, and resists fatigue. Production and maintenance personnel are not prone to eye fatigue when staring at PCB boards for a long time, causing less eye damage.

2. Low cost. As green is the mainstream in the production process, the procurement volume of natural green paint will be larger, and the procurement cost of green paint will be lower compared to other colors. At the same time, using the same color paint for mass production can also reduce the cost of changing lines.

Is the black pcb board more high-end?

From around 2007, people began to pay attention to the color of PCB board. This is mainly because high-end versions of large factories such as Asustek and Microstar have adopted black PCB color designs, so people gradually believe that black PCB boards must be high-end. But in reality, this perception is not correct. The difference between black PCBs and other color PCBs such as green PCBs, blue PCBs, and yellow PCBs is the color of the final solder resist paint applied. If the PCB design and manufacturing processes are identical, color will not have any impact on performance or heat dissipation. As for black PCBs, the surface wiring is almost completely covered, causing great difficulties for later maintenance. Therefore, black PCBs are a color that is not very convenient to manufacture and use. Moreover, black PCBs have the highest difficulty in matching holes, so the yield rate is relatively lower than other color PCBs, so the price of black PCBs is relatively expensive. The reason for the statement "color represents high-end or low-end products" is that manufacturers prefer to use black PCBs to manufacture high-end products, while using red, blue, green, and yellow to manufacture low-end products. To sum up, products give color meaning, not color. Whether it's a black pcb board or a green PCB board, a good board has good performance and heat dissipation.