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 1.0 104 A/cm2 and 7.5 103 A/cm2 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.