Thursday, February 19, 2009

US Patent 7492019 - High stiffness thin film cap for MEMS

Silicon nitride and metal materials have been used to form cap layer for micromechanical pressure sensors and similar applications but can be susceptible to damage to to harsh environments of pressure differentials outside of a particular tolerance. this patent from IC Mechanics teaches a MEMS device incorporating higher stiffness materials to remedy this problem. Claim 1 reads:

1. A MEM device comprising:

a substrate;

a microstructure formed on said substrate; and

a high-stiffness thin-film cap structure forming at least one wall of a sealed cavity encapsulating said microstructure, having a thickness between about 5 and 50 μm, and a Young's modulus of at least about 80 GPa.