Study on high reliable design method for lead-free solder joints on electronic components

This paper presents the high reliability design method for lead-free solder joints on chip components, and that is able to evaluate effect of soldering process for solder joint shape. Coupled analysis of structure analysis and flow analysis was proposed for replication of solder wetting and behavior of electric components at the same time. The analysis methods enable to evaluate complex mechanism of solder joint shape formation caused by soldering process fluctuation including the interaction between factors. Then, the estimated model of solder joint was evaluated the fatigue life using crack propagation analysis based on finite element method. The crack propagation method was provided the improvement for the complex behavior elucidation of crack propagation mode. Also, this paper indicated the importance of the analysis method for reliability design of solder joint in products required small-size and high reliability like automotive electronic components.