Abstract
In this paper, we suggest a practical simulation method for estimating the fatigue life of a solder joint on a chip component, which is the most severe component of lead-free solder-joint reliability in automotive electronic components. The complicated behavior of crack propagation in the solder joint was revealed using the proposed method. The shape of the solder joints affects the crack propagation mode of the joint. In particular, the crack of the solder joint propagated along the side of the chip component or through the solder fillet. In the case of the crack through the solder fillet, the fatigue life of the solder joint decreases significantly. Also, a high reliability design method for solder joints on chip components was indicated using the relation between the shapes of the solder joints and the crack propagation modes. Furthermore, the availability and applicability of this method for other chip components was validated by experiment.
