Micromotors and methods of fabrication

Abstract

A polysilicon micromotor, of either inner rotor or outer rotor design, is fabricated with a process that uses as few as three mask steps. In an outer rotor (wobble) micromotor, a free-rotating insulating flange bearing mechanically couples the inner periphery of the rotor to the stator, permitting the outer periphery of the rotor to be directly coupled to other mechanisms. The dielectric constant of the flange bearing increases motive torque of the motor as contrasted with air-gap designs. This and other factors results in motive torque, in the illustrated embodiment, more than 100 times larger than in previous designs. Among its other benefits, the disclosed fabrication process results in in-place formation of all motor elements, and enables precise definition of the rotor/stator gap.

Dependencies are inferred from the claim text.