Analysis of a novel method for measuring residual stress in micro-systems

• Published in: Journal of micromechanics and microengineering 2005-05, Vol.15 (5), p.921-927
• Main Authors: Elata, David, Abu-Salih, Samy
• Format: Article
• Language: English
• Subjects: Applied sciences; Electronics; Exact sciences and technology; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Mechanical engineering. Machine design; Mechanical instruments, equipment and techniques; Microelectronic fabrication (materials and surfaces technology); Micromechanical devices and systems; Physics; Precision engineering, watch making; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices
• ISSN: 0960-1317; 1361-6439
• DOI: 10.1088/0960-1317/15/5/004

A novel method for measuring residual stress is proposed and analyzed in this study. The method is based on the electromechanical bifurcation response of a clamped-clamped beam. The stressed beam is subjected to a symmetric electrostatic field. The presented analysis shows that the critical voltage which induces the bifurcation response is a monotonic function of the residual stress. Furthermore, the electromechanical bifurcation occurs for both compressive and tensile residual stresses. Ensuring that the postbuckling response is non-stable facilitates the identification of the bifurcation response. To this end, geometrical conditions are derived which ensure that the postbuckling state of the system is non-stable. It is shown that a single test structure can be used to measure residual stress in a continuous wide range.