Northrop Grumman Litef Gmbh

Litef Gmbh

Peter Leinfelder

Wolfram Geiger

Thomas Gessner

Julian Bartholomeyczik

Eberhard Handrich

Bruno F Ryrko

Maik Wiemer

Martin Hafen

Egbert Vetter

Guenter Spahlinger

Günter Spahlinger

Stefan Koenig

Stefan König

The invention relates to an acceleration sensor () having a sensor material () which is mounted by means of spring elements () so as to be movable along a movement axis (x) over a substrate (), first trim electrodes () which are connected to the sensor material (), and second trim electrodes () which are connected to the substrate () and are associated with the first trim electrodes (). When the sensor material is deflected along the movement axis, a spring force acting on the sensor material () is generated by the spring elements (), and when the sensor material () is deflected, an electrostatic force acting on the sensor material (), which counteracts the spring force, is generated by application of an electrical trim voltage between the first trim electrodes () and the second trim elements ().

Acceleration sensor having spring force compensation

The invention relates to an acceleration sensor () comprising an excitation mass () having excitation electrodes (), which excitation mass is movably mounted over a substrate () along a movement axis (x) and comprising detection electrodes () which are permanently connected to the substrate () and allocated to the excitation electrodes (). A first group of pairings () of excitation electrode () and allocated detection electrodes () is suitable for deflecting the excitation mass () along the movement axis (x) in a first direction (). A second group of pairings () of excitation electrodes () and allocated detection electrodes () is suitable for deflecting the excitation mass () along the movement axis (x) in a second direction (), which is opposite the first direction (). The number of pairings () in the first group is equal to the number of pairings () in the second group. The averaged distance between excitation electrodes () and detection electrodes () of the pairings () of the first group corresponds to the averaged distance between excitation electrodes () and detection electrodes () of the pairings () of the second group.

Acceleration sensor having a reduced bias and manufacturing method for an acceleration sensor

The invention relates to an acceleration sensor, comprising a substrate having a substrate surface and a sample mass that is movable relative to the substrate in a first direction (x) parallel to the substrate surface. The sample mass has a comb-like electrode that is movable together with the sample mass and has a plurality of teeth, which extend in the first direction (x). The acceleration sensor further comprises a counter-electrode fixedly connected to the substrate, which counter-electrode has a fixed comb-like electrode and wherein said fixed comb-like electrode has a plurality of teeth which extend in a direction opposite to the first direction (x). The teeth of the movable comb-like electrode engage with the teeth of the fixed comb-like electrode. The acceleration sensor further comprises a shielding electrode fixedly connected to the substrate and which is suitable for increasing a pneumatic damping of the sample mass during a deflection movement of the sample mass.

Acceleration sensor and method for producing an acceleration sensor

A Coriolis gyroscope comprises a mass system that can be excited to perform vibrations parallel to a first axis, whereby a deflection of the mass system due to a Coriolis force along a second axis perpendicular to the first axis is detectable. At least one first correction unit and at least one second correction unit, which each comprise a plurality of stationary correction electrodes and moving correction electrodes whereby the stationary correction electrodes extend in the direction of the first axis and are firmly connected to the substrate by corresponding anchor structures, and the moving correction electrodes are provided as a part of the mass system. A method for reducing the quadrature bias of a Coriolis gyroscope of this type comprises applying at least temporarily constant corrective voltages to the correction units.

Coriolis gyroscope having correction units and method for reducing the quadrature bias

A rotation rate sensor comprises a substrate and two structures which move relative to the substrate on a design plane (x-y), with the two moving structures being coupled to form a coupled structure such that the coupled structure has a first oscillation mode with antiphase deflections of the moving structures in a first direction (x) on the design plane (x-y) as excitation mode. The coupled structure has a second oscillation mode as a detection mode which is excited by Coriolis accelerations when the first oscillation mode is excited and on rotation about a sensitive axis (z) of the rotation rate sensor. The sensitive axis is at right angles to the design plane (x-y), and the coupled structure is designed such that, subject to optimal preconditions, it does not have any oscillation mode which can be excited by linear accelerations of the rotation rate sensor in a direction parallel to the second axis.

Rotation rate sensor

A high precision micromechanical accelerometer comprises a layered structure of five (5) semiconductor wafers insulated from one another by thin oxide layers. The accelerometer is formed by first connecting a coverplate and a baseplate to associated insulating plates. Counter-electrodes, produced by anisotropic etching from the respective insulating plates, are fixed to the coverplate and the baseplate respectively. The counter-electrodes are contactable through the cover or baseplate via contact windows. A central wafer contains a unilaterally linked mass (pendulum) that is also produced by anisotropic etching and which serves as a movable central electrode of a differential capacitor. The layered structure is hermetically sealed by semiconductor fusion bonding. A stepped gradation from the top is formed at a wafer edge region for attaching contact pads to individual wafers to permit electrical contacting of individual wafers. The invention permits fabrication of a .mu.B device characterized by extremely small leakage capacitances and high temperature stability.

Micromechanical accelerometer with plate-like semiconductor wafers

A high precision micromechanical accelerometer comprises a layered structure of five (5) semiconductor wafers insulated from one another by thin semiconductor material oxide layers. The accelerometer is formed by first connecting a coverplate and a baseplate to associated insulating plates. Counter-electrodes, produced by anisotropic etching from the respective insulating plates, are fixed to the coverplate and the baseplate respectively. The counter-electrodes are contactable through the cover or baseplate via contact windows. A central wafer contains a unilaterally linked mass (pendulum) that is also produced by anisotropic etching and which serves as a movable central electrode of a differential capacitor. The layered structure is hermetically sealed by semiconductor fusion bonding. A stepped gradation from the top is formed at a wafer edge region for attaching contact pads to individual wafers to permit electrical contacting of individual wafers. The invention permits fabrication of a .mu.B device characterized by extremely small leakage capacitances and high temperature stability.

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Ehrenkirchen, Germany

Peter Leinfelder