Analysis and Measurement of Residual Stress in Bridge Membrane MEMS Relays

Abstract

Microelectromechanical system (MEMS) relays are gradually replacing traditional relays because they are smaller and lighter and consume less power. However, performance parameters of MEMS relays, such as the pull-down voltage, response time, and resonant frequency, often deviate from those originally designed, due to residual stress generated during the fabrication process. We present herein a method to measure this residual stress, based on a metal bridge membrane MEMS relay, with the help of a nanoindenter and the finite-element method (FEM). The testing result lies in a reasonable range, indicating that this simple method is reliable and helpful for MEMS relay optimization.