Silicon MEMS components: a fatigue life assessment approach

Abstract

A fatigue damage approach for life assessment of silicon micro-components is proposed. The components of this model have been developed based on the physics of crack initiation and damage progress on the most damaging planes. This approach may be of great importance in durability assessment of silicon-based MEMS components while the complexity of testing equipment, micro-sized specimen preparation, and the high expenses associated with the fatigue tests of micro-components are of great concern. Fatigue damage accumulation of silicon micro-components is accompanied with the formation of inclined micro-critical planes of {111} on the fracture surface as a means of dissipating energy during fatigue damage progress, which coincides with the theory of fatigue damage accumulation in Varvani’s approach (2000). Predicted fatigue lives based on the damage model were found in good agreement with experimental fatigue life data of these components reported in the literature. Correlations are within a factor of ±2.5 for short and long lives, which are within the limits of acceptance.