Microstructural and physical characteristics of Sn-Ag-Cu-Mg Lead-free Solders

摘要

Sn-Ag-Cu-Mg lead-free solders based on a eutectic Sn-Ag-Cu alloy were prepared by means of orthogonal experimental design. The melting temperature and the wettability of Sn-Ag-Cu-Mg solders were tested by differential thermal analysis (DTA) method and SAT solder checker respectively. Combined with the microstructure analysis, the influence of trace addition of Mg on the melting points and wettability was investigated. The results indicate that Mg, combined with the other alloying elements Ag and Cu, plays a key role in modifying the melting characteristics of the alloy solders. And with the added Mg, the wettability of solders is depressed.