ESD testing and combdrive snap-in in a MEMS tunable grating under shock and vibration

Subramanian Sundaram, Maurizio Tormen, Branislav Timotijevic, Robert Lockhart, Ross P. Stanley, Herbert R. Shea, Sonia Garcia-Blanco, Rajeshuni Ramesham
2011 Reliability, Packaging, Testing, and Characterization of MEMS/MOEMS and Nanodevices X  
This work describes a method for tracking the dynamics of electrostatic discharge (ESD) sensitive MEMS structures during ESD events, as well as a model for determining the reduced combdrive snap-in voltage under vibration and shock. We describe our ESD test setup, based on the human body model, and optimized for high impedance devices. A brief description of the MEMS tunable grating, the test structure used here, and its operation is followed by results of the measured complex device dynamics
more » ... ring ESD events. The device fails at a voltage up to four times higher than that required to bring the parts into contact. We then present a model for the snap-in of combfingers under shock and vibration. We combine the results of the analytical model for combdrive snap-in developed here with a shock response model to compute the critical shock acceleration conditions that can result in combdrive snap-in as a function of the operating voltage. We discuss the validity regimes for the combdrive snap-in model and show how restricting the operation voltage below the snap-in voltage is not a sufficient criterion to ensure reliable operation especially in environments with large disturbances.
doi:10.1117/12.873253 fatcat:snhcf4t4xvhknnglz42mtzlv6i