Abstract:
The invention relates to a microelectromechanical structure, and more particularly, to systems, devices and methods of compensating the effect of the thermo-mechanical stress by incorporating and adjusting elastic elements that are used to couple a moveable proof mass to anchors. The proof mass responds to acceleration by displacing and tilting with respect to a moveable mass rotational axis. The thermo-mechanical stress is accumulated in the structure during the courses of manufacturing, packaging and assembly or over the structure's lifetime. The stress causes a displacement on the proof mass. A plurality of elastic elements is coupled to support the proof mass. Geometry and configuration of these elastic elements are adjusted to reduce the displacement caused by the thermo-mechanical stress.
Abstract:
The invention relates to a microelectro-mechanical structure (MEMS), and more particularly, to systems, devices and methods of compensating effect of thermo-mechanical stress on a micro-machined accelerometer by incorporating and adjusting elastic elements to couple corresponding sensing electrodes. The sensing electrodes comprise moveable electrodes and stationary electrodes that are respectively coupled on a proof mass and a substrate. At least one elastic element is incorporated into a coupling structure that couples two stationary electrodes or couples a stationary electrode to at least one anchor. More than one elastic element may be incorporated. The number, locations, configurations and geometries of the elastic elements are adjusted to compensate an output offset and a sensitivity drift that are induced by the thermo-mechanical stress accumulated in the MEMS device.
Abstract:
The invention relates to a microelectro-mechanical structure (MEMS), and more particularly, to systems, devices and methods of compensating effect of thermo-mechanical stress on a micro-machined accelerometer by incorporating and adjusting elastic elements to couple corresponding sensing electrodes. The sensing electrodes comprise moveable electrodes and stationary electrodes that are respectively coupled on a proof mass and a substrate. At least one elastic element is incorporated into a coupling structure that couples two stationary electrodes or couples a stationary electrode to at least one anchor. More than one elastic element may be incorporated. The number, locations, configurations and geometries of the elastic elements are adjusted to compensate an output offset and a sensitivity drift that are induced by the thermo-mechanical stress accumulated in the MEMS device.
Abstract:
The present invention relates to a microelectromechanical structure, and more particularly, to systems, devices and methods of incorporating z-axis out-of-plane stoppers that are controlled to protect the structure from both mechanical shock and electrostatic disturbance. The z-axis out-of plane stoppers include shock stoppers and balance stoppers. The shock stoppers are arranged on a cap substrate that is used to package the structure. These shock stoppers are further aligned to a proof mass in the structure to reduce the impact of the mechanical shock. The balance stoppers are placed underneath the proof mass, and electrically coupled to a balance voltage, such that electrostatic force and torque imposed by the shock stoppers is balanced by that force and torque generated by the balance stoppers. This structure is less susceptible to mechanical shock, and shows a negligible offset that may be induced by electrostatic disturbance caused by the shock stoppers.
Abstract:
The present invention relates to a microelectromechanical structure, and more particularly, to systems, devices and methods of incorporating z-axis out-of-plane stoppers that are controlled to protect the structure from both mechanical shock and electrostatic disturbance. The z-axis out-of plane stoppers include shock stoppers and balance stoppers. The shock stoppers are arranged on a cap substrate that is used to package the structure. These shock stoppers are further aligned to a proof mass in the structure to reduce the impact of the mechanical shock. The balance stoppers are placed underneath the proof mass, and electrically coupled to a balance voltage, such that electrostatic force and torque imposed by the shock stoppers is balanced by that force and torque generated by the balance stoppers. This structure is less susceptible to mechanical shock, and shows a negligible offset that may be induced by electrostatic disturbance caused by the shock stoppers.
Abstract:
Various embodiments of the invention reduce stiction in a wide range of MEMS devices and increase device reliability without negatively impacting performance. In certain embodiments, stiction recover is accomplished by applying electrostatic forces to electrodes via optimized voltage signals that generate a restoring force that aids in overcoming stiction forces between electrodes. The voltage signals used within a stiction recovery procedure may be static or a dynamic, and may be applied directly to existing electrodes within a MEMS device, thereby, eliminating the need for additional components. In some embodiments, the voltage is estimated or calibrated and swept through a range of frequencies that contains one or more resonant frequencies of the mechanical structure that comprises the parts to be detached.
Abstract:
The invention relates to a microelectromechanical structure, and more particularly, to systems, devices and methods of compensating the effect of the thermo-mechanical stress by incorporating and adjusting elastic elements that are used to couple a moveable proof mass to anchors. The proof mass responds to acceleration by displacing and tilting with respect to a moveable mass rotational axis. The thermo-mechanical stress is accumulated in the structure during the courses of manufacturing, packaging and assembly or over the structure's lifetime. The stress causes a displacement on the proof mass. A plurality of elastic elements is coupled to support the proof mass. Geometry and configuration of these elastic elements are adjusted to reduce the displacement caused by the thermo-mechanical stress.