Lead free solder material compatibility and technological factors

Implementation of lead free soldering process needs new experience based on plenty of investigation in the way of effects and interactions during soldering. Material selection of solder alloy composition, type of flux, substrate surface treatments, temperature profile including influence of controlled/noncontrolled soldering atmosphere in optimized soldering process have to be compatible to reach the best results in wetting characteristics, solder joint formation, and final solder joint reliability. This paper is focused on wetting and spreading phenomena including investigation of effects and interactions during lead free solder process. There were compared SA and SAC solders with SnPb. Design of experiments (DOE) was used as very useful tool to help in this characteristic study