3D Modelling of MEMS Components for Coupled Elastic — Electrostatic Characterization

This paper presents a method for modelling MEMS components whereby the designer can perform precise electrical, mechanical, and coupled electrical and mechanical simulations. Both surface and bulk micromachined components can be modelled at a geometrical level by defining simplified pseudo processes for a commercial CAD tool such as CovertorWare. The procedure for this approach is described with emphasis on the bulk case. A motivating example of a simple comb-finger structure in an accelerometer shows that this method is required to obtain adequate precision. A long thin bulk micromachined mirror array, which is not easily described analytically, was modelled by using a pseudo process and the coupled field problem of its elastic-electrostatic behaviour has been investigated.