Abstract
When we estimate the fatigue life, we have to conduct FE analysis using a constitutive model which can exhibit the mechanical properties of lead-free solder alloy. As such mechanical properties of lead-free solder joints under cyclic thermal loading, the stress strain curves, stress strain hysteresis loops and stress relaxation curves with these temperature dependencies and these rate dependencies are regarded. In addition, these solder joints under cyclic temperature load are stressed mainly in shear and the solder alloys have scale effect. Thus in this study, for FE analysis of solder joints under cyclic temperature load, we carried out tensile tests, tension-compressive tests and the stress-relaxation tests of lead-free solder alloy using the small sized shear specimen.
