Solder Resist is an insulating paint that is used to coat the surface of printed circuit boards.
The resist prevents solder from sticking to the parts when components are mounted on the board and protects the coatings from dust, heat and moisture, as well as insulates the elements from each other, preventing short circuits.
Solder resists are categorized by film formation methods into alkaline etch solution, UV cured, and thermally cured. 1. Alkaline etching solution is a solution composed of copper chloride (CuCl2, 2H2O), hydrochloride (HCl), hydrogen peroxide (H2O2) and water (H2O) 2. UV curable is a type of resist that cures when exposed to ultraviolet light. 3. heat-cured solder is a solder resist that hardens when exposed to heat.