Contact Force Models, including Electric Contact Deformation, for Electrostatically Actuated, Cantilever-Style, RF MEMS Switches

R.A. Coutu_Jr. and P.E. Kladitis
Air Force Institute of Technology, US

Keywords: microelectromechanical systems, micro-switch, contact force, contact resistance

Abstract:
Electrostatically actuated, cantilever-style, metal contact, radio frequency (RF), microelectromechanical systems (MEMS) switches depend on having adequate contact force to achieve desired, low contact resistance. In this study, contact force equations that account for beam tip deflection and electric contact material deformation are derived. Tip deflection is modeled analytically using beam bending theory and contact material deformation is modeled as elastic, plastic, or elastic-plastic. Contact resistance predictions, based on Maxwellian theory and newly derived contact force equations, are compared to experimental results. Contact force predictions not considering tip deflection or material deformation overestimate contact force and result in underestimated contact resistance. Predictions based on the new contact force models agree with measurements.

Nanotech 2004 Conference Technical Program Abstract