Numerical Simulation of Stress-Induced Failure in Aluminum Conductors of a Microelectronic Package Based on Surface and Grain Boundary Diffusion.

Abstract

The stress-induced failure in an aluminum conductor of a microelectronic package was investigated in terms of diffusion along the surface and grain boundary. The mechanism of the growth of groove, which initiated at and progressed along a grain boundary perpendicular to the stress at elevated temperature, was proposed and the failure process was numerically simulated. The grooving process was found to be sensitive to thermal stress as well as the diffusion ratio, F=(grain boundary diffusion)/(surface diffusion). The active grain-boundary-diffusion brought about a crack-like groove at high magnitudes of F and/or stress, whereas the low magnitudes led to a V-shaped groove and marked thinning of the conductor.