MEMS Mechanics for Stress-Induced Static Displacement & Dynamic Analysis

Microfabrication Residual Stress Modeling

Focusing on MEMS design considerations, CoventorWare offers unique capabilities to model residual stress induced by microfabrication

Residual stress in MEMS structures can take the form of generic anisotropic or isotropic pre-stress, differences in CTE of laminated layers, or varying stress gradients in multi-composite structures.  Residual stress can cause deviations from expected device response, structural deformation or even device failure due to gross buckling. CoventorWare can be used to model this critical component of MEMS design. With the ability to represent an array of residual stress configurations, CoventorWare enables accurate prediction of both static and dynamic device responses. The graphic displays static deformation and dynamic response predicted from modeling the application of residual stress in CoventorWare.

Static deformation and dynamic response predicted from application of residual stress

Advanced Pre-Stress Conditions Modeling

Unlike macroscale applications, the thin-film nature of most MEMS structures requires accurately resolving deformation resulting from the relaxation of fabrication-induced residual stress

Coupled with CoventorMP’s unique capabilities in modeling the large aspect ratio features inherent in MEMS applications (such as conformal deposition), CoventorWare provides accurate modeling of advanced pre-stress conditions. The graphic illustrates a StressXX vector plot of applied pre-stress, including the gradient profile through a composite anchor structure featuring conformal deposition.