Evaluation of Pb-free solders for adaptability to various soldering processes

In this paper, the authors evaluated the efficiency and productivity of an SMT and iron-machine soldering process using Sn-Ag-Cu type solders. This solder is superior to conventional ones in terms of strength, heat fatigue resistance and toughness. The results obtained are as follows: (1) in SMT processes using Sn-Ag-Cu type solders, the quality of products and efficiency obtained are similar to conventional solders, when small electric parts are selected; and (2) in iron-machine soldering processes, Sn-Ag-Cu solder is similar to conventional solders when the iron temperature is high.