Microstructure and properties of Sn-Ag and Sn-Sb lead-free solders in electronics packaging: a review

Electronic devices need to work at high temperature in some fields for a long time, peculiarly step soldering technology, primary packaging and flip-chip connections, etc., along with the application of electronic products more and more widely. These phenomena promote the further development of high-temperature solders. Because of the high melting temperatures of Sn-Ag and Sn-Sb, they are suitable for high-temperature fields such as automotive electronics and avionics. In this review, the influences of trace elements and nanoparticles on microstructure, intermetallic components (IMC) growth, mechanical properties, wettability, melting behavior, and creep behavior of Sn-Ag and Sn-Sb solders have been summarized systematically. It was found that the addition of trace elements or nanoparticles into solders to be beneficial in improving the performance of Sn-Ag and Sn-Sb solders. Besides, the melting behavior of the solder at high temperatures can be further improved if Sn-Ag and Sn-Sb are used better as high-temperature solders.