In-situ moire interferometry technique and its applications to microelectronic packages

In this study, an in-situ multifunctional micro-moire interferometry system (M3I) was developed. The system can be used to conduct the deformation measurement of electronic packages subjected to thermal/thermal cycling, thermal/moisture, and thermal/mechanical loadings. With the system, the long-term reliability of a plastic ball grid array (BGA) assembly was studied. The fatigue life predicted by the in-situ moire interferometry technique was found to be very close to that obtained from the accelerated thermal cycling (ATC) tests. The system was also employed to investigate the fracture behavior of a copper/solder/copper sandwiched sample. It was found that the system is a useful experimental tool for a multilayer material bonded system for the determination of stress intensity factors (SIFs), strain energy release rate, and phase angle.