Pb-FREE THERMAL CYCLE ACCELERATION FACTORS

Society is demanding tougher legislation to minimize or even eliminate perceived health risks to people. Since the European Union began drafting requirements in support of RoHS (Restriction of Hazardous Substances), companies have been scrambling to address the critical transition from eutectic SnPb to Pb-free solder for electronic assemblies. Activities have focused heavily on understanding fundamental material properties and their changes during higher temperature processing. The most important question that must be answered is how these new materials will perform in the equivalent customer environment. This paper will discuss the calculation of acceleration factors for different Pb-free solders, comparing results with those for eutectic SnPb, while also evaluating several approaches and their ability to predict field reliability.