HASL Line (Lead and Lead Free)

Hot air leveling HASL, hot air solder leveling.It is a process of applying molten tin-lead solder to the PCB surface and leveling (blowing flat) with heated compressed air to form a coating that is both resistant to copper oxidation and provides good solderability. Hot air leveling flat solder and copper at the junction of copper tin metal compounds, the thickness of about 1 ~ 2mil.

The PCB should be immersed in molten solder when hot air is leveled and the air knife blows the liquid solder before the solder solidifies and minimizes the meniscus of the solder on the copper side and prevents solder bridging