Take out the screws of electronics devices in your home and you will notice that most of them have a common feature. You are likely to notice that most electronic devices have green colored printed circuit boards (PCBs). Sure, nowadays there are other color options also available for PCBs such as red, blue, black, white, etc. However, if you consider the majority, printed circuit boards are still largely green in color. It makes us wonder if this is deliberate or just something that evolved in that manner. To better understand the topic, here are some key reasons why circuit boards (PCBs) are mostly green in color.
Origins in military – Green is one of the colors used in camouflaging military uniforms, equipment, weapons, etc. Some experts say that it was the military that chose green as the color for their circuit boards and electronic devices, as it matched with their camouflaged clothing and equipment. From there, it became normal for circuit boards to be green in color.
Solder mask – The original color of a circuit board is usually a dull yellow shade. It’s the green colored solder mask that gives the green tone to the circuit board. Solder mask is applied to protect the golden colored copper traces that run throughout the circuit board. It protects the electronic traces from dust, moisture and corrosion. While nowadays various colors are available as solder mask, green colored units are still in majority. Solder mask in red, blue, black, yellow, white, etc. are usually seen on motherboards that are meant to be used with a transparent casing.
Less fatigue – For repair technicians who have to work on circuit boards for several hours at a stretch, green color is a lot less tiring on the eyes. It has been noted in research studies that green has a relaxing effect on the mind. Try staring at yellow or red color for few minutes and you can easily see how it can start to stress your eyes. On the other hand, green colored circuit boards can be easily dealt with.
Easy to spot issues – Green color works to provide an appropriate contrast against the golden colored copper traces and connectors. The green-golden contrast is just right and does not stress the eyes. This makes it easier to spot issues on the circuit board such as corrosion, bridged connections, etc. Repairing also becomes easier with the green-golden combo.
Physical superiority – Technically, green colored solder mask has superior qualities. Over the years, a lot of research has gone into creating the perfect solder mask. As most of this research utilized green colored solder mask, it currently has superior physical properties. For example, green colored solder mask can be used to create solder mask dams of 0.1mm, which is the lowest possible. Other colors like yellow, red and blue have solder mask dams of 0.12 mm.
Most affordable – As most manufacturing units are currently programmed to use green colored solder mask, it works out cheaper to produce circuit boards. In case you want a different color, the manufacturer will need to use separate equipment for the same. This will naturally increase production cost.