Strain analysis of IC packages using a scanning Moire method

Abstract

This study investigates the thermal deformations of an electronics package using a SEM (scanning electron microscope) Moire method and compares the results with those obtained using an optical Moire method. The specimen used to obtain Moire fringes to evaluate thermal deformations was a flip-chip ball grid array (FCBGA) package. The shear strains in different solder joints were analysed using the SEM Moire method. The results were then compared to those obtained. using an optical Moire interferometry technique, and they coincided well. The scanning Moire technique can be a useful method for deformation study of a wide range of problems in deformation analysis. Deformation measurement with a high resolution is possible by using the SEM Moire technique. The advantages and disadvantages of a full field optical Moire, a micro optical Moire, and two scanning Moire methods are also compared in this paper.