Fracture mechanics study of fatigue crack growth in solder joints under drop impact

This paper describes the use of a fracture mechanics-based modeling approach to explain two interesting experimental observations in solder joints subjected to high speed cyclic bending, namely 1) the evolution of the crack front from a positive to a negative curvature; and 2) the initial acceleration and the subsequent retardation of the crack growth rate. Two- dimensional crack fronts in the solder joint were modeled, and J-integral along the crack front was computed. The modeling results have provided physical insights into the experimentally observed crack growth phenomena.