A Coupled Field Multiphysics Modeling Approach to Investigate RF MEMS Switch Failure Modes under Various Operational Conditions

Abstract

In this paper, the reliability of capacitive shunt RF MEMS switches have been investigated using three dimensional (3D) coupled multiphysics finite element (FE) analysis. The coupled field analysis involved three consecutive multiphysics interactions. The first interaction is characterized as a two-way sequential electromagnetic (EM)-thermal field coupling. The second interaction represented a one-way sequential thermal-structural field coupling. The third interaction portrayed a two-way sequential structural-electrostatic field coupling. An automated substructuring algorithm was utilized to reduce the computational cost of the complicated coupled multiphysics FE analysis. The results of the substructured FE model with coupled field analysis is shown to be in good agreement with the outcome of previously published experimental and numerical studies. The current numerical results indicate that the pull-in voltage and the buckling temperature of the RF switch are functions of the microfabrication residual stress state, the switch operational frequency and the surrounding packaging temperature. Furthermore, the current results point out that by introducing proper mechanical approaches such as corrugated switches and through-holes in the switch membrane, it is possible to achieve reliable pull-in voltages, at various operating temperatures. The performed analysis also shows that by controlling the mean and gradient residual stresses, generated during microfabrication, in conjunction with the proposed mechanical approaches, the power handling capability of RF MEMS switches can be increased, at a wide range of operational frequencies. These design features of RF MEMS switches are of particular importance in applications where a high RF power (frequencies above 10 GHz) and large temperature variations are expected, such as in satellites and airplane condition monitoring.

Role of the electro-thermo-mechanical multiple coupling on the operation of RF-microswitch

“…Nevertheless, operation of the RF-microswitch may lead evenly to a collapse due to buckling (Shamshirsaz 2008) or to a dynamic resonance (Brusa and Munteanu 2006a;Brusa 2006c). Mechanical design of the RF-microswitch consequently requires an extensive experimental identification of its static and dynamic behaviors, respectively, to prevent some critical conditions in operation (Sadek et al 2009). Strength of material has to be tested as it looks at microscale and after the microfabrication process (Baek et al 2005).…”

Investigation of Acoustic Injection on the MPU6050 Accelerometer

“…In previous studies, a series of methods have been adopted to analyze the reliability of MEMS. Khaled et al reported an approach to analyze RF-MEMS switch failure by multi-physics simulation [8]. Wei et al built a correlation model for monitoring data to reconstruct the sensor that failed in measurement [9].…”

Instability of Contact Resistance in MEMS and NEMS DC Switches under Low Force: the Role of Alien Films on the Contact Surface

“…On the other hand, the reliability of RF MEMS switches is a major concern for long term applications. There have been a number of reports in this area, including both experimental measurements [ 3 – 6 ] and computational simulations [ 7 , 8 ]. Generally, for capacitive switches, the lifetime is affected by the charging effects in the dielectric layer, and for ohmic-contact switches, the reliability is limited by the metal contacts.…”