Soldering method using a Cu-containing lead-free alloy

摘要

Members to be soldered, such as printed circuit boards having electronic parts mounted thereon, are subjected to flow soldering in a solder bath with a Cu-containing lead-free solder. When the molten solder in the solder bath falls below a prescribed level, the molten solder is replenished with a material having a lower Cu content than the initial composition of the solder bath. Flow soldering can be continued for long periods with the Cu content of the solder bath being maintained substantially constant.