Mechanical parameters, especially mechanical stress of membranes used in silicon microphones strongly depend on the manufacturing process. As a result, deviations during this process can result in sensitivity variations of the microphone. Therefore, the stress should be well controlled within a certain tensile level. This paper describes a method to test devices electrically using the MEMS related pull-in phenomenon with respect to the mechanical compliance of microphone membranes. Using this method, out of specification chips can be detected at an early stage within the manufacturing process instead of determination at a system functionality test after packaging. Therefore, the adequacy for the intended use of the pull-in voltage and its dependency on varying tensile stress due to manufacturing tolerance is evaluated.

Date Published: 17 May 2013
PDF: 11 pages
Proc. SPIE 8763, Smart Sensors, Actuators, and MEMS VI, 876326 (17 May 2013); doi: 10.1117/12.2016835

Published in SPIE Proceedings Vol. 8763:
Smart Sensors, Actuators, and MEMS VI
Ulrich Schmid; José Luis Sánchez de Rojas Aldavero; Monika Leester-Schaedel, Editor(s)