Analysis of a pre-stressed bi-material accelerated-life-test (ALT) specimen

Application of mechanical pre-stressing could be an effective means for achieving a failure-mode-shift-free ``destructive ALT effect{''} in electronic and photonic devices and micro-electro-mechanical systems (MEMS). A simple, physically meaningful and easy-to-use analytical ({''}mathematical{''}) predictive model has been developed to assess the magnitude and the distribution of stresses in a bi-material assembly subjected to the combined action of thermally induced (considered by the ALT design) and external ({''}mechanical{''}) pre-stressing. Such a compressive pre-stressing is applied to the assembly component that is expected to experience thermal compression. The model is an extension and a modification of the author's 1986 and 1989 ``bi-metal thermostat{''} models suggested as a generalization of the 1925 Timoshenko's theory. (C) 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim