Effects of humidity and temperature cycling on 3-D packaging

Three dimensional electronics packaging technologies are emerging for many electronics system applications. Characterizing failure mechanisms, was the focus of this research. Accelerated testing and observing samples at various stages of the testing, with an Environmental Scanning Electron Microscope, were the primary methods used. Interfacial debonding of polyimides and fatigue cracking in bus structures were observed in humidity cycling and thermal cycling. These failures were the result of differential expansion of polyimide adhesives and dielectrics and interfacial degradation by moisture absorption.