High temperature deformation of area array packages by moire interferometry/FEM hybrid method

Abstract

In this study, moire interferometry and experimental/FEM hybrid method were applied in the thermal deformation analysis of several area array packages. High frequency gratings of 1200 l/mm and 600 l/mm were replicated onto the cross sections of packages at the elevated temperature of 80/spl deg/C or 160/spl deg/C. These packages include an OMPAC BGA and a flip-chip BGA. The thermal deformation of these packages were measured by moire interferometry. Warpage of the packaging systems was measured and the effects of the bonding, encapsulation, soldering, and geometry on the deformation were discussed. The strain distributions inside the solder joints were analyzed by both moire interferometry and experimental/FEM hybrid method.