Triaxial membrane accelerometer
First Claim
1. A micro-machined three-axis accelerometer structure, comprising:
- a substrate, an elastically deformable thin-layer membrane suspended above the substrate and secured to the substrate at a periphery of the membrane,a proof mass suspended above the membrane and linked to the membrane by a central stud located at a center of the membrane, andcapacitive interdigitated combs formed along a first and second parallel sides of the proof mass and along a third and fourth parallel sides of the proof mass, said combs comprising movable plates secured to the mass and fixed plates secured to the substrate,means for producing a first linear combination of the capacitance values of combs formed along said first and second parallel sides of the proof mass, said first linear combination representing an acceleration along a horizontal axis parallel to said first and second sides of the proof mass,means for producing a second linear combination of the capacitance values of combs formed along said first, second, and third and fourth sides of the proof mass, said second linear combination representing an acceleration along a vertical axis perpendicular to the membrane, and means for producing a third linear combination of the capacitance values of combs formed along said third and fourth parallel sides of the proof mass, said third linear combination representing an acceleration along a horizontal axis parallel to said third and fourth sides of the proof mass.
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Accused Products
Abstract
The invention relates to accelerometer structures micro-machined according to micro-electronics technologies. The accelerometer according to the invention comprises a substrate, an elastically deformable thin-layer membrane suspended above the substrate and secured to the substrate at its periphery, a proof mass suspended above the membrane and linked to the latter by a central stud, and capacitive interdigitated combs distributed about the mass, having movable plates secured to the mass and fixed plates secured to the substrate. The fixed plates and movable plates of the various combs are of differentiated heights to help in the discrimination of the upward and downward vertical accelerations.
72 Citations
17 Claims
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1. A micro-machined three-axis accelerometer structure, comprising:
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a substrate, an elastically deformable thin-layer membrane suspended above the substrate and secured to the substrate at a periphery of the membrane, a proof mass suspended above the membrane and linked to the membrane by a central stud located at a center of the membrane, and capacitive interdigitated combs formed along a first and second parallel sides of the proof mass and along a third and fourth parallel sides of the proof mass, said combs comprising movable plates secured to the mass and fixed plates secured to the substrate, means for producing a first linear combination of the capacitance values of combs formed along said first and second parallel sides of the proof mass, said first linear combination representing an acceleration along a horizontal axis parallel to said first and second sides of the proof mass, means for producing a second linear combination of the capacitance values of combs formed along said first, second, and third and fourth sides of the proof mass, said second linear combination representing an acceleration along a vertical axis perpendicular to the membrane, and means for producing a third linear combination of the capacitance values of combs formed along said third and fourth parallel sides of the proof mass, said third linear combination representing an acceleration along a horizontal axis parallel to said third and fourth sides of the proof mass. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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Specification