Low-cycle Thermal Fatigue of a Surface-mount Electronics Assembly

The solder joints of surface-mount electronic devices may fail because of low-cycle fatigue. Combined with differences in thermal expansion properties for the various components of the assembly, cyclic thermal loading induces stress reversals and the potential accumulation of inelastic strain in the joints. Predicting solder joint fatigue life requires a thorough understanding of the deformation and failure mechanisms of the solder alloy and an accurate

calculation of the stresses and strains in the joint. In this Technology Brief, a thermal fatigue analysis of a surface mount electronic assembly is conducted using the Abaqus/Standard low-cycle fatigue capability. With a cost efficient direct cyclic procedure, material models for

the creep of regular and lead-free solder, and the ability to model the initiation and evolution of material damage, Abaqus/Standard can provide an accurate prediction of solder joint fatigue failure.