Thermal Fatigue Life of Solder Bumps in BGA

抄録

Fatigue life estimation of solder bumps is one of the most critical technologies for the development of ball grid array packages(BGA). In this study, strain singularity was examined based on the analytical results for the primary solder bump model. The result suggested that it was desirable to employ the equivalent creep strain range occurring at a distance of 0.05 mm from the singularity point. The fatigue life estimation of the actual solder bumps was performed based on this consideration. The estimation result for the crack initiation was in good agreement with the experimental results. A simple estimation of the crack propagation based on the linear damage law was also proposed for convenience' sake. The trend of the simple estimation results corresponded well with the experimental results of crack propagation. Therefore, the fatigue life estimation of solder bumps based on the present method is satisfactory for engineering purposes.