Accelerometer with low sensitivity to thermo-mechanical stress

摘要

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.

主权项

1. A micro-machined inertial sensor, comprising:
a proof mass that is suspended above a substrate and attached with a moveable electrode; a plurality of stationary electrodes, electrically coupled to the moveable electrode, the plurality of stationary electrodes forming a sensing capacitor with the moveable electrode such that movement of the proof mass leads to a capacitive variation of the sensing capacitor that is further converted to a sensing output; and wherein the plurality of stationary electrodes is coupled to at least one anchor on the substrate via a coupling structure that incorporates at least one elastic element, at least one elastic element being incorporated to couple two stationary electrodes of the plurality of stationary electrodes.