Capacitive micromechanical sensor structure and micromechanical accelerometer

摘要

The invention relates to a capacitive micromechanical sensor structure comprising a stator structure rigidly anchored to a substrate and a rotor structure movably anchored by means of spring structures to the substrate. The stator structure has a plurality of stator finger support beams and the rotor structure has a plurality of rotor finger support beams. Stator fingers along the stator finger support beam of the stator structure extend into rotor gaps along the rotor finger support beam of the rotor structure, and rotor fingers along the rotor finger support beam of the rotor structure extend into stator gaps along the stator finger support beam of the stator structure.

主权项

1. A capacitive micromechanical sensor structure comprising:
a stator structure rigidly anchored to a substrate and a rotor structure movably anchored by spring structures to the substrate,
the stator structure having a plurality of stator finger support beams,the rotor structure having a plurality of rotor finger support beams, a stator finger support beam of the stator structure comprising a stator finger structure along at least one side of the stator finger support beam, wherein the stator finger structure comprises a plurality of stator fingers and stator gaps between two adjacent stator fingers, a rotor finger support beam of the rotor structure comprising a rotor finger structure along at least one side of the rotor finger support beam, wherein the rotor finger structure comprises a plurality of rotor fingers and rotor gaps between two adjacent rotor fingers, stator fingers along the stator finger support beam of the stator structure extending into rotor gaps along the rotor finger support beam of the rotor structure, rotor fingers along the rotor finger support beam of the rotor structure extending into stator gaps along the stator finger support beam of the stator structure; characterized by a stator fingertip gap between the stator fingers of the stator finger structure and the rotor finger support beam being in unloaded state of the capacitive micromechanical sensor structure one to 2.5 times a finger side gap between the stator fingers of the stator finger structure and the rotor fingers of the rotor finger structure, and a rotor fingertip gap between the rotor fingers of the rotor finger structure and the stator finger support beam being in unloaded state of the capacitive micromechanical sensor structure one to 2.5 times the finger side gap between the stator fingers of the stator finger structure and the rotor fingers of the rotor finger structure, and the rotor structure being movably anchored to the substrate in such way that the rotor structure can be deflected at least parallel with the plane of the substrate so that the rotor fingertip gap between the rotor fingers along at least one side of the rotor finger support beam and the stator finger support beam changes, the stator fingertip gap between the stator fingers along at least one side of the stator finger support beam and the rotor finger support beam changes, and a finger overlap length changes, the finger overlap length being the length the stator fingers of the stator finger structure extend into the rotor gaps of the rotor finger structure, or alternatively the length the rotor fingers of the rotor finger structure extend into the stator gaps of the stator finger structure, and wherein stopper bumps configured to prevent excess movement of the rotor structure with respect to the stator structure but allowing the rotor structure to move in two opposite directions a distance corresponding to a stopper gap that is
greater than 0.25 times the finger side gap between stator fingers of the stator finger structure along the side of the stator finger support beam and a rotor finger of the rotor finger structure along the side of the rotor finger support beam, andless than the rotor fingertip gap and less than the stator fingertip gap.