Abstract: A closed-loop, comb drive device that reduces certain “common mode” sensor errors. The device includes a comb structure, electronics, a substrate, and a position sensor. The comb structure includes two comb-drive sections, each having at least two subsections. The comb drive sub-sections in each section are positioned in a diagonal relationship to each other relative to the device axes. A separate pick-off section, along with the electronics, determine which of the two drive sections should receive a voltage differential, and the size of that differential. The diagonal relationship within each drive section eliminates many of the large scale factor errors which often occur in prior-art designs.

Abstract: A closed-loop, comb drive device that reduces certain “common mode” sensor errors. The device includes a comb structure, electronics, a substrate, and a position sensor. The comb structure includes two comb-drive sections, each having at least two subsections. The comb drive sub-sections in each section are positioned in a diagonal relationship to each other relative to the device axes. A separate pick-off section, along with the electronics, determine which of the two drive sections should receive a voltage differential, and the size of that differential. The diagonal relationship within each drive section eliminates many of the large scale factor errors which often occur in prior-art designs.

Abstract: A Micro-Electro-Mechanical System closed-loop (MEMS) inertial device having a vertical comb drive that exhibits improved performance under vibration. The device includes one or more stator tines extending from a housing into a cavity formed by the housing. One or more rotor tines extend from a proof mass located in the cavity. The proof mass is joined to the housing by flexures which allow movement in the vertical direction. The rotor tines have a first length value in the direction of movement and the stator tines have a second length value in the direction of movement. The second length value is greater than the first length value. Also, the stator tines include two electrically separated portions. The lesser length of the rotor tines relative to the stator tines causes the attractive force between the rotor tines and either the upper or lower half of the stator tines to be relatively independent of rotor vertical position. This, in turn, produces better accelerometer accuracy in vibration environments.

Abstract: A device and method for isolation of MEMS devices. A device includes a pair of substantially symmetrical wafers, each including a perimeter mounting flange and a cover plate, each cover plate and mounting flange separated by a plurality of tines. The cover plates of the wafers are bonded to the opposite sides of a device layer, and the system may then be bonded to other structures via the mounting flange. A method includes forming tines in a pair of wafers and bonding the wafers to opposite sides of a device layer. An alternative method includes bonding a pair of wafers to a device layer, then etching the isolation features.

Abstract: A microelectromechanical system (MEMS) device with a mechanism layer having a first part and a second part, and at least one cover for sealing the mechanism layer. The inner surface of at least one of the covers is structured such that a protruding structure is present on the inner surface of the cover and wherein the protruding structure mechanically causes the first part to be deflected out of a plane associated with the second part.

Abstract: A system for conditioning a sensor die. The sensor die may have a sensor wafer and a substrate wafer anodically bonded together. The sensor die may have an inertial device such as an accelerometer or a gyroscope. The device has a scale factor that may change with a bowing of the sensor die. The die may be bonded at a high temperature to bumps on a surface of a package, but may develop a bow when cooled down to a temperature such as room temperature when the coefficients of thermal expansion of the die and the package are different. The bump material may enter a yield state. The package and the die may be subjected to a high gravity environment to reduce or reverse the bow. After the package is removed from the high gravity environment, the bow may return but at a smaller magnitude when subject to similar conditions.

Abstract: Methods and apparatus for producing crystalline Quartz tuning-fork resonators using a deep reactive ion etching process. The resonators have an outline formed by a method including masking a substrate with a metal mask. The metal mask being resistant to reactive ion etching and conforming to the outline. The resulting plasma etched resonators are strong and have a high degree of symmetry, which substantially reduces common critical performance errors occurring in accelerometers, pressure sensors, tilt meters, scales, and rate gyroscopes.

Abstract: A method for a geometry of a lateral comb drive for an in-plane, electrostatic force feedback, closed-loop, micromachined accelerometer or closed-loop Coriolis rate gyroscope device, or closed-loop capacitive pressure or force measuring device. When vibration is applied to the device, the error in the time-average output, which is vibration rectification error, due to this input vibration is minimized or eliminated. The geometry resulting from practice of the present invention is space-efficient because drive force is maximized while vibration rectification is minimized or eliminated.

Abstract: An apparatus and method for sensor architecture based on bulk machining of Silicon-On-Oxide wafers and fusion bonding that provides a symmetric, nearly all-silicon, hermetically sealed MEMS device having a sensor mechanism formed in an active semiconductor layer, and opposing silicon cover plates each having active layers bonded to opposite faces of the sensor mechanism. The mechanism is structured with sensor mechanical features structurally supported by at least one mechanism anchor. The active layers of the cover plates each include interior features structured to cooperate with the sensor mechanical features and an anchor structured to cooperate with the mechanism anchor. A handle layer of each cover plate includes a pit extending there through in alignment with the cover plate anchor. An unbroken rim of dielectric material forms a seal between the cover plate anchor and the pit and exposes an external surface of the cover plate anchor.