FINITE ELEMENT MODELLING OF PZT ACTUATED MICRO-MIRROR SCANNER—EFFECT OF RESIDUAL STRESS

摘要

The effect of thermo-mechanical residual stress on the integrity and overall deflections of efficiently designed lead zirconate titanate (PZT) actuated micro-mirror scanner have been investigated in details taking anisotropic properties of silicon chip and PZT-material into account. The induced residual stress from scanner fabrication processes has shown to be substantial and highly dependant on thickness of underneath device silicon layer. A combined thermo-mechanical and piezoelectric simulation has been conducted and obtained results are compared with that of purely piezoelectric simulations to find the influence of residual-stress on deflections of micro-scanner. It is shown that the precise overall deflection of scanner depends significantly on the extent and the state of residual-stress. To obtain an optimal design of micro-mirror scanner, a priori finite element calculation for the prediction of its deflection taking residual stress into consideration is proved to be an essential step.