Hot Air Solder Leveling (HASL)

Hot Air Solder Leveling is a popular surface finish used on printed circuit boards with a long successful history.

To create the HASL finish, the printed circuit board will be submersed in molten solder (tin / lead). This solder will cover all the exposed copper surfaces. Upon retraction from the solder, high pressure hot air is blown over the surface through air knives, this levels the solder deposit and removes the excess solder from the board surface.

HASL provides a very reliable solder joint and shelf life. HASL makes component soldering very effective, but due to the thickness of HASL coating, the planarity of the surface may be unsuitable for fine-pitch components. The HASL deposit is made from a eutectic blend of tin and lead.

This finish is available on all Sunstone PCBs and at no additional cost.

HASL finish PCB