A photoresist (also known as a photoresist) is a light-sensitive substance that is based on ultraviolet light and undergoes deformation and solidification when exposed to it.

This process is very important in the electronics industry and usually very complex circuits with small tracks and one or two layers are used by this method, as you can see in the image below, MSP also makes some circuits using this method.

Note: Because in this process, ultraviolet rays and various chemical substances are used. If you do not have enough knowledge, it is very dangerous to be right.

pcb photoresist