Batch fabrication and assembly of micromotor-driven mechanisms with multi-level linkages

The development of a new technology for the wafer-level fabrication and assembly of fully integrated mechanisms is reported. It is based on a boron-doped bulk silicon dissolved wafer process that has been used to fabricate a variety of micromechanical devices. The overall process consists of three wafers, two silicon and one glass. The first silicon wafer is processed to create all the major mechanical elements, including gears and micromotors. The second is processed to create mechanical linkages between them. These wafers are successively aligned and bonded to a glass wafer, and then dissolved in ethylenediamine pyrocatechol (EDP) to free the mechanisms. This procedure permits wafer-level batch assembly of micromechanical systems. A number of 5-10-μm-thick bulk silicon electrostatic micromotors and gear trains have been fabricated and linked to each other on the same chip. Tests show that this is a viable technology that allows mechanical power to be coupled between various micromechanical devices