Lead free solder process development and reliability for handset application

Recent worldwide lead free activity has been driving international and US consumer electronic companies to be lead free. This paper identifies the challenges, critical issues and solutions for implementing lead free soldering process for handset application, and describes the studies conducted on Sn/Ag/Cu and Sn/Ag/Bi solder, process development and reliability results for handset manufacturing. The paper described wettability, printability and reflow results, electrical characterization, drop shock, thermal cycling test, humidity test and mechanical reliability results. Process DOE results are also discussed in the paper. Traditional eutectic solder is used as the baseline for comparison.