Optimisation of Lead Free Solders Reflow Profile

The solder reflow profile is one of the key variables in the manufacturing process that significantly impacts product yield. In this paper we discuss the details of developing solder profiles for IR and vapor phase soldering (VPS). This paper reviews the background of smaller process windows, along with specific comparisons to common practice with tin/lead and SAC alloys. The impacts on oven set-up and operation were investigated for significant differences between these profiles. Optimal reflow profile was determined based on the number of experiments realized for tin/lead and SAC solder pastes: mechanical properties, analyze of structures and electrical properties of solder joints.