Capacitive microelectromechanical accelerometer

A capacitive micromechanical accelerometer comprising

• a substrate which defines a substrate plane which extends in a transversal direction and a longitudinal direction, the transversal direction being perpendicular to the longitudinal direction,
• a first sensor for measuring acceleration along a vertical axis perpendicular to the substrate plane, and
• an accelerometer package with an inner package plane which is adjacent and parallel to the substrate plane above and/or below the substrate plane,
• wherein
• the first sensor comprises a rotor which is mobile in relation to the substrate, a rotor suspender, and one or more stators which are immobile in relation to the substrate,
• the rotor comprises one or more rotor electrodes and the one or more stators comprises one or more stator electrodes, the electrodes being configured for differential capacitive measurements,
• the suspender comprises one or more anchored rotor suspender bars and first and second transversal torsion springs aligned on a transversal rotor rotation axis, wherein the first and second transversal torsion springs are attached to the rotor,
• and wherein
• the rotor is a two-sided seesaw frame comprising at least a transversal rotor bar, a first longitudinal rotor bar attached to the transversal rotor bar and a second longitudinal rotor bar attached to the transversal rotor bar, wherein each longitudinal rotor bar extends from a first side of the transversal rotor rotation axis to a second side of the transversal rotor rotation axis, and
• each longitudinal rotor bar comprises one or more first damping plates on the first side of the transversal rotor rotation axis and one or more first damping plates on the second side of the transversal rotor rotation axis, and
• one or more second damping plates are fixed to the inner package plane above or below at least some of the one or more first damping plates, so that at least one first damping plate overlaps with the projection of a second damping plate to the substrate plane in a first overlap area on the first side of the transversal rotor rotation axis, and at least one first damping plate overlaps with the projection of a second damping plate to the substrate plane in a second overlap area on the second side of the transversal rotor rotation axis.