Review of microstructure and properties of low temperature lead-free solder in electronic packaging.

Low temperature solder (In-based, Sn-Bi, Sn-Zn) has great advantages in aerospace and through-hole technology assemblies in IBM mainframe due to its unique low temperature characteristics. The review evaluates the effects of alloying elements, rare earth elements and nanoparticles on the wettability, microstructure, mechanical properties and oxidation resistance of the low-temperature solders.