Why Are Printed Circuit Boards Green?
The most common colour used on PCBs is green. This is the cheapest colour to produce and the default colour for 21st century printed circuit boards. It was also the regulation colour for US military PCBs as it withstood harsh conditions best. As a result, green was a popular choice among manufacturers who primarily supplied the military. This colour also proved to be the cheapest option for non-military customers.
Solder mask protects traces from oxidation
A solder mask protects traces from oxidation, creating a strong electrical bond between components and boards. Its adhesive features help PCB designers firmly hold components on the board. Its role is to prevent oxidation of copper traces and to prevent the formation of solder bridges.
Solder masks can be applied during hand soldering or automatically using an automatic assembly system. Regardless of the method of assembly, a solder mask is an essential part of PCB fabrication. It helps prevent oxidation of copper traces, hinders unexpected connections and keeps dirt and dust from contaminating the board.
The manufacture of solder masks is a highly sophisticated process that requires advanced technology and up-to-date equipment. Because of the high precision and high-quality equipment involved, it is not possible to produce solder masks at home. A typical manufacturing process involves several steps, with the final step being thermal curing.
There are many types of solder masks available for PCB manufacturing. It is important to choose the right one for your project and needs. A PCB manufacturing expert will be able to advise you on the most suitable one. Copper is often difficult to connect if it is oxidized or smooth, so a solder mask is needed to protect it from oxidation.
A solder mask also protects traces from oxidation by preventing traces from bridging. This is particularly important for BGAs and fine-pitch traces. By defining a small gap between exposed pads and solder mask, a dam is created preventing molten solder from flowing onto neighboring pads. It also helps hold solder droplets in place during soldering.
One of the benefits of a green PCB is that it makes it easier to inspect it visually. When the PCB is green, employees can easily see all the parts and can perform manual screening more effectively. The green color is the most comfortable for the human eye, and it also creates noticeable contrast.
Previously, workers would use their bare eyes to check a board’s quality, but that was a tiring task. Researchers say the color green is calming to the brain. Human eyes are incredibly sensitive to green light. This means that a green PCB can clearly show any flaws on the external layers.
Green solder masks are another benefit. Using these masks can make PCB inspection less tiring. Human eye sensors are particularly sensitive to green light wavelengths, so a green solder mask will make it easier to see traces and residues on the board. Another reason for using green solder masks is that they are stronger and easier to mass-produce. PCB assembly services often use these masks in the manufacturing process to reduce worker fatigue.
Another reason why green PCBs are preferable is that green light has an anti-fatigue effect. Green light reduces eye strain and provides contrast, making it easier for workers to inspect a PCB visually. It also provides a soothing effect, which can reduce fatigue caused by prolonged manual inspections.
Improves human legibility
A green board makes it easier to distinguish individual circuit traces and pads. This color has the highest contrast of all the colors, making it easier for humans to inspect the boards. It is also the easiest colour for the human eye to perceive, so this colour is useful when working with small, intricate objects.
When printed circuit boards are green, it is easier for employees to examine the boards. The color’s contrast helps them to see all the parts of the board and conduct effective manual screening. Because green has a high contrast, it also reduces eye strain. This allows employees inspecting the boards to see all the circuitry.
Because of its contrast, green PCBs are easier for people to read, especially when paired with white text. Green PCBs are also easier to inspect by hand, which is a key benefit for manufacturers. As green is more easily visible than any other color, it can reduce the risk of eye strain and increase efficiency. As a result, green is a preferred color in many factories.
Green PCBs are much easier to read than those with white silkscreened identities. The colour is the best complement to human legible font. In the 1960s, Peter Skipping, founder of Artech Devices, created a PCB with green solder resistance that he soldered to the copper pads of the panel. This solder resistor protected the copper traces from the high temperatures of machine tinning.