The main aim of this study is to extending the holographic interferometry technique to measure the effect of the temperature ramp-up rate on the warpage of IC packages in the IR-reflow process . It is noted that both the warpage and the ambient temperature change can cause image fringes. Therefore, an auxiliary sphere is used to identify the fringe numbers caused by the ambient temperature change during the experiment. Then, the Taguchi method will be deduced to study the effect of the temperature ramp-up rate and peak waiting temperature on the warpage of PBGA package in the IR-reflow process.