Effect of Pr and Nd on microstructures and properties of lead-free solders

The research status on the development of lead-free solders bearing Pr and Nd were reviewed and the effects of Pr and Nd on the microstructure and properties of Sn-Ag-Cu, Sn-Cu(-Ni) and Sn-Zn solders were summarized systematically. Moreover, the reliability and tin whisker problems by adding Pr and Nd also were analyzed. Synchronously, the developing trends of rare earth elements modified solders were prospected, which provides a base support for the developing of new lead-free solders.