Passivation cracking analysis of integrated-circuit microstructures under aeronautical conditions

Passivation cracking is one of the main failures of integrated circuits (ICs). A major cause for these failures is the mismatch of thermal expansion coefficients, Young's modulus, and Poisson's ratios of the package materials. Here, the finite element simulations and the maximum principal stress theory are applied to investigate the effects of aeronautical conditions, mainly temperature and load cycles, on the local stress distribution in the passivation layers of IC microstructures. Passivation cracks are easy to initiate and to propagate because the aeronautical IC microstructures endure serious thermo-mechanical loading. The method also can be used to provide a basis for selecting passivation materials for aeronautical IC packages.