You might have seen black PCBs these days. The PCBs are not actually black but the solder mask of such PCBs are black because of numerous reasons. One of the main reason why solder mask is kept black is because the reflection of the light is not desired in such circuits.
The Solder Mask
The solder mask is the most vital component or material required for the production of Printed Circuit Boards. The solder mask is also known as the solder resist and its main purpose is to lacquer or varnish the entire surface of the PCB on both top and bottom for the formation of the protection layer which is permanent and the traces of copper are to be printed over it. The solder mask is the main agent to prevent the solder from coming in between the conductors and is also responsible for the creation of short in the circuit. The layer is also responsible for offering protection against the environment as well.
Different Colors of Solder Mask
The solder mask is often applied in different colors, such as it is often applied in greenish color. However, sometimes blue color is also applied. The less used colors are red, white, yellow, and black etc. But the applications where light reflection is required the black PCB is used. The applications where light is not needed to be transparent, the black solder mask is used for the best possible use of the light.
Qualities of Black PCB
The black solder mask is very helpful in the absorption of heat during the reflow. It depends on the user whether scaling up or down of the temperature is required to make the sensors used in the circuit safe. The silkscreen of black PCB are also prone for the turning light in to other colors such as brown for the heat absorption.