Acceleration sensor having a surrounding seismic mass

• US 20090282914A1
• Filed: 04/20/2009
• Published: 11/19/2009
• Est. Priority Date: 05/19/2008
• Status: Abandoned Application

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Rehle, Dirk
• Application Number:
  US12/386,612
• Publication Number:
  US 20090282914A1
• Time in Patent Office: Days
• US Class Current: 73/504.120
• CPC Class Codes: G01P 15/125 by capacitive pick-up
• CPC Class Codes: G01P 2015/0814 for translational movement of the mass, e.g. shuttle type

Abstract

A micromechanical acceleration sensor has a substrate, a suspension, a seismic mass, and stationary capacitive electrodes, which seismic mass is suspended over the substrate with the aid of the suspension. The seismic mass has a mass center of gravity, and the suspension has at least two anchors on the substrate, the at least two anchors being situated next to the mass center of gravity at a distance which is small compared to a horizontal extension of the seismic mass. The stationary capacitive electrodes are provided in recesses of the seismic mass. The seismic mass directly surrounds the suspension.

Claims

1. A micromechanical acceleration sensor, comprising:

a substrate;

a suspension having at least two anchors on the substrate;

a seismic mass suspended over the substrate with the aid of the suspension, wherein the seismic mass has a mass center of gravity and the seismic mass directly surrounds the suspension, and wherein the at least two anchors of the suspension being situated next to the mass center of gravity of the seismic mass at a distance which is substantially smaller compared to a horizontal extension of the seismic mass; and

multiple stationary capacitive electrodes provided in recesses of the seismic mass.

2. The micromechanical acceleration sensor as recited in claim 1, wherein the sensor is a linear acceleration sensor provided with at least one measuring axis.

3. The micromechanical acceleration sensor as recited in claim 2, wherein the seismic mass surrounds the suspension in the shape of a closed ring.

4. The micromechanical acceleration sensor as recited in claim 2, wherein the recesses have the shape of a closed ring.

5. The micromechanical acceleration sensor as recited in claim 3, wherein the suspension has at least one suspension beam.

6. The micromechanical acceleration sensor as recited in claim 3, wherein a spring element is situated on at least one end of the suspension beam, wherein a first area of the spring element is connected to the suspension beam and a second area of the spring element is connected to the seismic mass.

7. The micromechanical acceleration sensor as recited in claim 3, wherein two stationary capacitive electrodes are situated in each recess.

8. The micromechanical acceleration sensor as recited in claim 3, wherein one stationary capacitive electrode is situated in each corresponding recess.

9. The micromechanical acceleration sensor as recited in claim 3, wherein the stationary capacitive electrodes are individually anchored on the substrate.