Lead-free solder alloys have been around for as long as people have done soldering, with sources dating back about 5,000 years. Most of these alloys were combinations like copper-silver or silver ...

At the eutectic temperature of 183 C, three phases exist in equilibrium: (Pb) with the composition Pb-19 wt % Sn, (Sn) with the composition Pb-97.5 wt% Sn, and the liquid with the eutectic composition ...