Sensor element for sensing accelerations in three spatial directions

• US 8,353,213 B2
• Filed: 09/19/2008
• Issued: 01/15/2013
• Est. Priority Date: 09/26/2007
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Zoellin, Jochen, Franke, Axel, Leinenbach, Christina, Van Teeffelen, Kathrin
• Primary Examiner(s): Kwok, Helen C.
• Application Number:
  US12/678,669
• Publication Number:
  US 20100206076A1
• Time in Patent Office: 1,579 Days
• Field of Search: 735/143.2, 735/10, 735/11, 735/143.8, 735/141.8
• US Class Current: 73/514.32
• CPC Class Codes: G01P 15/0802 Details
• CPC Class Codes: G01P 15/125 by capacitive pick-up
• CPC Class Codes: G01P 15/18 in two or more dimensions
• CPC Class Codes: G01P 2015/084 the mass being suspended at more than one of its sides, e.g. membrane-type suspension, so as to permit multi-axis movement of the mass

Abstract

A sensor element is provided for sensing accelerations in three spatial directions, which furnishes reliable measurement results and moreover can be implemented economically and with a small configuration. The sensor element encompasses at least one seismic mass deflectable in three spatial directions, a diaphragm structure that functions as a suspension mount for the seismic mass, and at least one stationary counterelectrode for capacitive sensing of the deflections of the diaphragm structure. According to the exemplary embodiments and/or exemplary methods of the present invention, the diaphragm structure encompasses at least four electrode regions, electrically separated from one another, that are mechanically coupled via the seismic mass.

Claims

1. A sensor element for sensing accelerations in three spatial directions, comprising:

at least one seismic mass deflectable in three spatial directions;

a diaphragm structure that functions as a suspension mount for the seismic mass and encompasses at least one electrode; and

at least one stationary counterelectrode for capacitive sensing of deflections of the diaphragm structure;

wherein the diaphragm structure encompasses at least four electrode regions, electrically separated from one another, that are mechanically coupled via the seismic mass,

wherein the at least one stationary counterelectrode is perforated into a plurality of perforation openings.

2. The sensor element of claim 1, wherein the counterelectrode has an opening into which the seismic mass projects.

3. The sensor element of claim 1, wherein the diaphragm structure having the electrode regions separated electrically from one another, and the counterelectrode, are embodied in a layer configuration above a substrate, so that a hollow space is located between the electrode regions and the counterelectrode.

4. The sensor element of claim 3, wherein the seismic mass is patterned at least in part out of the same layer as the counterelectrode.

5. The sensor element of claim 3, wherein at least a portion of the seismic mass is patterned out of the substrate.

6. The sensor element of claim 3, wherein the hollow space is connected to a cavity or a trench via the perforation openings in the counterelectrode.

7. The sensor element of claim 1, wherein spring elements are embodied in the diaphragm structure as suspension mounts for each of the electrode regions.

8. The sensor element of claim 3, wherein the hollow space extends above the region of the at least one seismic mass.