TIN-ZINC LEAD-FREE SOLDER AND SOLDER-JOINED PART

摘要

A tin-zinc lead-free solder contains tin as a main component, at least 6-10 weight% of zinc essentially, 0.0015 to 0.03 weight% of magnesium, and 0.0010 to 0.006 weight% of aluminum. When a paste of the solder is stored in a cool ed state or even at temperatures above the room temperature, the oxide protecti ve film formed from magnesium and aluminum on solder particles protects the inside, the shelf life is prolonged by suppressing the reaction between the zinc and an activator, a favorable wettability can be maintained because the oxide protective film is subject to breakage when the solder is heated and melted.