Patent ID: 6928873

Claim:
A silicon dual inertial sensor having a structure made of a ( 110 ) silicon chip with a bulk-micromachining method in a form of a parallelogram, said structure comprising: an outer frame; a central anchor; a plurality of connecting blocks; a first inner frame and a second inner frame each having a plurality of sensing beams connected to a proof-mass, and a plurality of driving beams connected to said outer frame or two common connection beams positioned at two sides of said proof-mass and then connected to said central anchor with a plurality of common supporting beams, each side of said first or second inner frame perpendicular to a y-axis forming a driver body which has a plurality of long trenches or slits formed perpendicular to the y-axis on each surface, said y-axis being in parallel with a surface of said silicon chip; and two insulation sheets connected to said outer frame, said central anchor and said connecting blocks, said insulation sheets being positioned respectively on a front side and a back side of said silicon chip, each insulation sheet having a plurality of metal thin film electrodes each being formed corresponding to a surface of a proof-mass of said first or second inner frame to form a sensing capacitor, and a plurality of electrode surface areas each being formed with two sets of stripe electrodes corresponding to a driver body of said first or second inner frame, said two sets of stripe electrodes being interposed to each other and in parallel to said long trenches or slits of the corresponding driver body to form two sets of driving capacitors; wherein an electrostatic force is generated to make the proof-mass of said first inner frame and the proof-mass of said second inner frame move in opposite directions along said y-axis when an oscillating signal with a proper phase is imposed on each of said driving capacitors, a Coriolis force is generated to make the proof-mass of said first inner frame and the proof-mass of said second inner frame move in opposite directions along a z-axis perpendicular to the surface of said silicon chip when a rotation rate exists along an x-axis in parallel with the surface of said silicon chip, and the proof-mass of said first inner frame and the proof-mass of said second inner frame move in a same direction along said z-axis when an acceleration exists along said z-axis.