In certain embodiments, an accelerometer is a microelectromechanical systems (MEMS) device including a proof mass, an anchor located in an opening defined by a body of the proof mass, a spring, a drive electrode, and a sense beam. The spring and the proof mass form a spring system suspended from the anchor. The sense beam oscillates at a particular resonance frequency based on application of a signal to the drive electrode. The MEMS device further includes a support structure coupled to the anchor. The support structure operates as a stress decoupling area and includes a support beam, with the spring corresponding to an end of the support beam that has a reduced thickness. The sense beam has a first end attached to the proof mass and a second end attached to the support beam such that the sense beam is orthogonal to the support beam.

An inertial sensor, includes: a substrate; a fixing portion that is provided on the substrate; a first movable body that faces the substrate and that is displaceable with a first support beam as a first rotation axis; the first support beam that is arranged in a first direction and that couples the first movable body and the fixing portion; a second movable body that is displaceable due to deformation of a second support beam; the second support beam that is arranged in a second direction intersecting the first direction and that couples the first movable body and the second movable body; and a protrusion that is provided on the substrate or the second movable body, overlaps the second movable body in plan view from a third direction and that protrudes toward the second movable body or the substrate.

Provided is a physical quantity sensor including: a movable body; a base body; and a lid body, in which the movable body is accommodated in a space between the base body and the lid body, the space is sealed with a melt portion obtained by melting a through hole provided in the lid body, the lid body and the melt portion contain silicon, and the melt portion has a continuous curved surface having unevenness.

An inertial sensor includes: a substrate; a fixing part arranged at one surface of the substrate; a moving element having an opening and configured to swing about a rotation axis along a first direction; a support beam supporting the moving element as the rotation axis in the opening of the moving element; and a support part supporting the support beam. The support part includes a first part fixed to the fixing part, and a second part formed only of a part not fixed to the fixing part. A length in the first direction of the second part is longer than a length in the first direction of the first part.

There is provided a resonant sensor comprising: a substrate; a proof mass suspended from the substrate by one or more flexures to allow the proof mass to move relative to the frame along a sensitive axis; a first and a second resonant element connected between the frame and the proof mass; wherein the proof mass is positioned between the first and the second resonant element along the sensitive axis, and wherein the first and the second resonant elements have a substantially identical structure to one another; and drive and sensing circuitry comprising: a first electrode assembly coupled to first drive circuitry configured to drive the first resonant element in a first mode; a second electrode assembly coupled to second drive circuitry configured to drive the second resonant element in a second mode, different to the first mode; and a sensing circuit configured to determine a measure of acceleration.

This disclosure describes techniques of configuring capacitive comb fingers of an accelerometer resonator into discreet electrodes with drive electrodes and at least two sense electrodes. The routing of electrical signals is configured to produce parasitic feedthrough capacitances that are approximately equal. The sense electrodes may be placed on opposite sides of the moving resonator beams such that the changes in capacitance with respect to displacement (e.g. dC/dx) are approximately equal in magnitude and opposite in sign. The arrangement may result in sense currents that are also opposite in sign and result in feedthrough currents of the same sign. The sense outputs from the resonators may be connected to a differential amplifier, such that the difference in output currents may mitigate the effect of the feedthrough currents and cancel parasitic feedthrough capacitance. Parasitic feedthrough capacitance may cause increased accelerometer noise and reduced bias stability.

A resonant sensor including a support, a proof body suspended from the support and having a resonant frequency ωa, means for measuring a force including at least one resonator of resonant frequency ω.sub.rn, said force being applied by the proof body, and a mechanical decoupling structure interposed between the proof body and the resonator, said decoupling structure including a decoupling mass, a first connecting element between the decoupling mass and the proof body, a second connecting element between the decoupling mass and the resonator, the decoupling structure having a main vibration mode whose resonant frequency ω.sub.d is such that ωa <ω.sub.d< ω.sub.rn, said decoupling structure forming a mechanical low-pass filter between the proof body and the resonator.

FIG. 1

A physical quantity sensor includes, when three directions orthogonal to one another are defined as a first direction, a second direction, and a third direction, a substrate; and a moving member facing the substrate in the third direction via a gap and becoming displaced in the third direction in relation to the substrate. The moving member has a first region that has a plurality of penetration holes penetrating the moving member in the third direction and having a square opening shape as viewed from the third direction, and a second region having no penetration hole. At least one of a length in the first direction and a length in the second direction of the second region is equal to or greater than S0+2×S1, where S0 is a length of one side of the penetration hole, and S1 is a space between the penetration holes next to each other.

The present invention relates to capacitive micromechanical accelerometers, and in particular to acceleration sensors with movable rotors which may rotate out of a substrate plane when the accelerometer undergoes movement with an acceleration component perpendicular to the substrate plane. The capacitive micromechanical accelerometer includes additional damping springs to reduce unwanted movement of the rotor in the substrate plane, thereby reducing the parasitic capacitance that results from motion of the rotor in the substrate plane. The damping springs are vertically recessed with respect to other components of the accelerometer in order to minimise the effect of the damping springs on movement of the rotor out of the substrate plane.

A microelectromechanical device comprising a mass, an electromechanical transducer configured to convert, after damping the mass during a first damping period, displacement of the mass in the first and second directions into corresponding first and second electrical signals during corresponding first and second conversion time periods, a derivative unit configured to generate first and second control signals indicative of the velocity of the mass in the first and second direction, and a controller for providing the first and second control signals to respective first and second one or more electrodes of the electromechanical transducer for simultaneously damping the mass in the first and second directions with a first and second damping forces corresponding to the first and second velocity during the damping time period.