Patent ID: 6471883
Filing Date: 2002-10-29
Classification: G01C

Abstract:
A method of manufacturing a vibrating structure gyroscope having a silicon substantially planar ring vibrating structure, capacitive means for imparting drive motion to and sensing motion of the vibrating structure, and a screen layer surrounding the capacitive means, said method including the steps of:depositing a first layer of photoresist material on to one surface of a plate like glass or silicon substrate, hardening, patterning and developing the first photoresist layer to expose selected areas of the substrate, etching said exposed areas of the substrate to form cavities therein, stripping the remaining first layer photoresist material from the cavitated substrate attaching a layer of silicon to the cavitated said one surface of the substrate, depositing a layer of aluminum on the surface of the silicon layer opposite the surface attached to the substrate, depositing a second layer of photoresist material on to the outermost surface of the aluminum layer with respect to the silicon layer, hardening, patterning and developing the second photoresist layer to expose selected areas of the aluminum layer, etching said exposed areas of the aluminum layer to leave on the silicon layer regions of aluminum providing bond pads for grounding the screen layer, bond pads forming connection points for the capacitive drive and sensing means, and bond pads for electrical connection to the silicon substantially planar ring vibrating structure, stripping the remaining second photoresist layer from the aluminum layer, depositing a third layer of photoresist material on to the silicon layer over the remaining deposited aluminum layer regions, hardening, patterning and developing the third layer of photoresist material to expose selected areas of the silicon layer, deep reactive ion etching the exposed selected areas of the silicon layer to form, from the silicon layer, the capacitive drive and sensing means, the surrounding screen layer and the substantially planar ring vibrating structure mounted by a hub above the substrate cavities providing unrestricted oscillation of the ring structure, and electrically isolating each of the capacitive drive and sensing means, screen layer and ring vibrating structure from one another.