What is HASL Finish
HASL Finish, short for Hot Air Solder Leveling Finish, is a commonly used surface finish that involves immersing the circuit boards in a bath of molten solder, which covers the exposed copper surfaces. The excess solder is then removed, and the PCB is leveled using a hot air knife. The primary purpose of HASL Finish is to provide a solderable surface for the PCB’s components.