Observing real-time thermal deformations in electronic packaging

Summary

A robust scheme of moiré interferometry for real-time observation of thermal deformations was developed. It was implemented with a convection-type heating/cooling environmental chamber, which produced rapid temperature control. Vibrations caused by the environmental chamber were circumvented by rigid links that connected the specimen to the moiré interferometer rather than supporting the specimen by the chamber. The result was exceptionally stable fringes. The system was utilized to document temperature-dependent behavior of a PBGA package assembly.