Creep Crack Growth Prediction of Solder Joints During Temperature Cycling—An Engineering Approach

Abstract

A model is developed which predicts the creep damage accumulation in solder joints during temperature cycling. The model relates the crack growth rate to the rate of creep energy density dissipated using the C* parameter of nonlinear fracture mechanics for extensive creep damage. For a eutectic tin-lead solder joint, the damage due to both grain boundary sliding and matrix creep is considered. The validity of the model is proved by correlating the predicted fatigue life of solder joints for 84 I/O leadless ceramic chip carriers with the published measured data for a number of test conditions. The published experimental conditions are simulated in a three dimensional, nonlinear, time and temperature dependent finite element analysis. For each test condition, both components of creep energy density, i.e., energy densities because of grain boundary sliding and matrix creep, are determined separately in the finite element analysis. The values are then used to determine the crack growth parameters and predict the crack growth rate in the solder joint using the crack growth model. The predicted results are found to have good correlation with the measured fatigue life for each test condition.