Experimental and modelling study on the effects of refinishing lead-free microelectronic components

Hot Solder Dip (HSD) of electronic components originally manufactured with lead-free solder finishes is seen as a potential solution for making these components available and used in high reliability and critical safety equipment. In this process, also referred as “refinishing”, tin and tin-reach alloy coatings on package terminations are replaced with tin-lead solder thus reducing the risk of failures caused by tin whisker growth. Characterising the effect of HSD process on refinished components from thermo-mechanical point of view is critical. This paper details the findings of an integrated experimental and modelling study that aimed at assessing the impact of the thermal shock induced from HSD on several different Quad Flat Package (QFP) variants and in relation to their subsequent long-term reliability.