Micromechanical sensor element, method for manufacturing a micromechanical sensor element and method for operating a micromechanical sensor element

• US 8,627,719 B2
• Filed: 07/09/2009
• Issued: 01/14/2014
• Est. Priority Date: 07/18/2008
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Offenberg, Michael, Baus, Michael
• Primary Examiner(s): Macchiarolo, Peter
• Assistant Examiner(s): Shah, Samir M
• Application Number:
  US12/459,993
• Publication Number:
  US 20100011860A1
• Time in Patent Office: 1,650 Days
• Field of Search: 735/143.2, 735/141.6, 438/50, 257/E21.211
• US Class Current: 73/514.32
• CPC Class Codes: G01P 15/125 by capacitive pick-up
• CPC Class Codes: G01P 2015/0831 the mass being of the paddle type having the pivot axis between the longitudinal ends of the mass, e.g. see-saw configuration

Abstract

A micromechanical sensor element includes: a substrate; a first seismic mass suspended from the substrate, which is deflectable from a first rest position by an acceleration acting perpendicularly to a main plane of extension; and a second seismic mass, which is deflectable from a second rest position by the acceleration. At least a partial overlap is provided between the first seismic mass and the second seismic mass perpendicular to the main plane of extension.

Claims

1. A micromechanical sensor element, comprising:

a substrate;

a first seismic mass suspended from the substrate, wherein the first seismic mass is rotatable from a first rest position by an acceleration acting perpendicularly to a main plane of extension of the first seismic mass; and

a second seismic mass suspended from the substrate asymmetrically from the first seismic mass and rotatable by the acceleration from a second rest position;

wherein at least a partial overlap between the first seismic mass and the second seismic mass is provided perpendicular to the main plane of extension.

2. The micromechanical sensor element as recited in claim 1, wherein the first seismic mass is fastened on the substrate rotatably about a first axis of rotation using a first coupling device, and wherein the second seismic mass is fastened on the substrate rotatably about a second axis of rotation using a second coupling device, the first and second axes of rotation being situated at least one of (a) in parallel to each other, and (b) substantially congruently perpendicular to the main plane of extension.

3. The micromechanical sensor element as recited in claim 2, wherein the first seismic mass has a first mass symmetry axis and the second seismic mass has a second mass symmetry axis, the first and second mass symmetry axes being oriented substantially parallel to the first and second axes of rotation, and the first mass symmetry axis being situated so as to be set apart from the second mass symmetry axis in parallel to the main plane of extension.

4. The micromechanical sensor element as recited in claim 3, wherein the mass of the first seismic mass and the mass of the second seismic mass differ.

5. The micromechanical sensor element as recited in claim 3, wherein the first seismic mass and the second seismic mass are integrated into a housing having a cover.

6. The micromechanical sensor element as recited in claim 1, wherein the first and second coupling elements are situated congruently and perpendicularly to the main plane of extension, and wherein the first and second coupling elements are at least one of torsional and bending spring elements.

7. The micromechanical sensor element as recited in claim 1, wherein (a) the first coupling element is fastened directly on the substrate, and (b) the second coupling element is fastened directly on at least one of the first coupling element, the substrate and the first seismic mass.

8. A micromechanical sensor element comprising:

a substrate;

a first seismic mass suspended from the substrate, wherein the first seismic mass is deflectable from a first rest position by an acceleration acting perpendicularly to a main plane of extension of the first seismic mass; and

a second seismic mass deflectable by the acceleration from a second rest position;

wherein at least a partial overlap between the first seismic mass and the second seismic mass is provided perpendicular to the main plane of extension;

wherein the first seismic mass is fastened on the substrate rotatably about a first axis of rotation using a first coupling device, and wherein the second seismic mass is fastened on the substrate rotatably about a second axis of rotation using a second coupling device, the first and second axes of rotation being situated at least one of (a) in parallel to each other, and (b) substantially congruently perpendicular to the main plane of extension;

wherein the first seismic mass has a first mass symmetry axis and the second seismic mass has a second mass symmetry axis, the first and second mass symmetry axes being oriented substantially parallel to the first and second axes of rotation, and the first mass symmetry axis being situated so as to be set apart from the second mass symmetry axis in parallel to the main plane of extension;

wherein the first seismic mass has first and second first-seismic-mass electrodes, wherein the second seismic mass has first and second second-seismic-mass electrodes, and wherein an overlap is provided perpendicularly to the main plane of extension between the first first-seismic-mass electrode and the first second-seismic-mass electrode, and between the second first-seismic-mass electrode and the second second-seismic-mass electrode.

9. The micromechanical sensor element as recited in claim 8, wherein (a) at least one of the first mass symmetry axis and the first axis of rotation extends between the first and second first-seismic-mass electrodes, and (b) at least one of the second mass symmetry axis and the second axis of rotation extends between the first and second second-seismic-mass electrodes.