Extraction Method for the Residual Stress in Multilayer Microplates Under Large Deflection Based on Static Deflection Analysis

Abstract

This investigation presents a method of extraction of the built-in stress in films grown by thin-film deposition or growing in microplate structures. Although thin-film deposition processes are well controlled, the stress values might significantly vary, reaching ±40% of the projected value. The assumption of variance yields more accurate solutions for the deflection than the values obtained by assuming the exact interlaminar stress yielded by the deposition process. The extraction method was used in conjunction with a gradient-based optimization method to evaluate the effective stress based on the response of the microplate to distributed load. The estimation of the deflection in the model versus the experimental method is based on static deflection matching. The estimation of root-mean-square error based on the proposed model was reduced to 0.38% versus the experimental evaluation, while the deflection resulting from the assumption of the nominal interlaminar stress yield errors of up to 40% versus experiments. [2014-0220]