Finite element analysis for thermal fatigue life estimation of PBGA solder joints with model validation by experimental data

A previous experimental study was conducted to characterize the thermal fatigue life of PBGA solder joints under temperature cycling condition. The thermal cycling profile was one-hour cycles with a temperature range from -40°C to 125°C. The thermal cycling test lasted up to 3,000 cycles and the Weibull characteristics were obtained. In the present study, a computational model is established for the analysis of solder joint thermal fatigue life. The current approach is a finite element based creep analysis and the previous experimental data are used for model validation. In this presentation, the results of two types of plastic ball grid array assemblies are presented. The solder material under investigation is eutectic 63Sn-37Pb. The comparison between computational and experimental results shows good agreement. Both qualitative and quantitative comparisons appear to be satisfactory. Therefore, the present computational model is validated with good confidence. This study has demonstrated that the two dimensional finite element analysis should be sufficient for estimating the thermal fatigue life of solder joints in PBGA assemblies. Compared with the tedious three dimensional analysis, this advantage saves a tremendous amount of modeling and computing time for numerical simulation.