Rapid diagnosis of electromigration induced failure time of Pb-free flip chip solder joints by high resolution synchrotron radiation laminography

We performed a rapid diagnosis of electromigration induced void nucleation and growth in Pb-free flip chip solder joints. Quantitative measurements of the growth rate of voids during the stressing by 1.0×10 4 A/cm 2 and 7.5×10 3 A/cm 2 at 125°C were conducted by synchrotron radiation high resolution x-ray laminography. The results were analyzed by the statistical model of Weibull distribution function [W. Weibull, ASME Trans. J. Appl. Mech. 18 (3), 293 (1951)] of lifetime data. The Johnson-Mehl-Avrami phase transformation theory is proposed to provide a physical link to the statistical model and to estimate the lifetime of the joints at early stages.