What is ETCH Resist
ETCH resist is a protective material used during the PCB fabrication process to safeguard specific areas of the PCB from being chemically removed or etched while allowing other sections to be etched as intended.
During the etching process, where copper and other materials are selectively removed from the PCB, the ETCH resist material acts as a mask or barrier. It is applied to cover the portions of the PCB that need to be protected from the etching solution. This resist material must possess two key characteristics: resistance to the etchant and ease of application and removal.
By applying the ETCH resist material, the desired copper traces and features are shielded from the etching solution, ensuring their preservation. Once the etching process is complete, the ETCH Resist material is removed, and the protected areas remain intact. The removal of the resist material may result in a reduction in the height of the copper traces, known as undercut.