Effects of aeronautical conditions on passivation cracking of micro-structures of IC packages

Abstract

Passivation cracking is one of the main failures of ICs and thermo-mechanical failures are the root cause. A major cause for these failures is due to the different coefficients of thermal expansion (CTE), different Young's modulus, Poisson's ratios of package materials under different temperatures and some mechanical loadings. Therefore the working conditions of compound materials used here is expected to have a pronounced influence on the local stress distribution in the passivation layer. The aeronautical conditions mainly include different temperatures and overloads as well as the vibration conditions. Here the finite element simulations and the maximum principal stress theory are applied to investigate the effects of aeronautical conditions on passivation cracking of microstructures of IC packages, and the result paves the way for compound materials selection in IC packages and usage under aeronautical conditions