Rotation-rate sensor

• US 7,260,991 B2
• Filed: 02/25/2003
• Issued: 08/28/2007
• Est. Priority Date: 08/24/2002
• Status: Expired due to Term

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Hauer, Joerg, Maurer, Dieter
• Primary Examiner(s): Williams; Hezron
• Assistant Examiner(s): Shah; Samir M.
• Application Number:
  US10/513,907
• Publication Number:
  US 20050223800A1
• Time in Patent Office: 1,645 Days
• Field of Search: 735/35
• US Class Current: 73/535
• CPC Class Codes: G01C 19/5712 the devices involving a micromechanical structure

Abstract

A micromechanical rotation-rate sensor includes a substrate, an anchoring device provided on the substrate, as well as a first spiral spring device and a second spiral spring device, the two spiral spring devices being provided next to one another in mirror symmetry along their greatest extension, and the two spiral spring devices together form one spiral spring apparatus. The sensor further includes a centrifugal mass connected to the anchoring device via the first spiral spring device connected to the centrifugal mass so that the centrifugal mass is elastically deflectable from its neutral position, about a rotational axis situated perpendicularly to a substrate surface, so that the centrifugal mass is capable of rotary oscillation. In addition, the first spiral spring device includes a bend at its anchoring region with the anchoring device.

Claims

1. A micromechanical rotation-rate sensor comprising:

a substrate;

an anchoring device provided on the substrate;

a first spiral spring device and a second spiral spring device, wherein the two spiral spring devices are provided next to one another in mirror symmetry along their greatest extension, and wherein the two spiral spring devices together form one spiral spring apparatus; and

a centrifugal mass connected to the anchoring device via the first and second spiral spring devices connected to the centrifugal mass so that the centrifugal mass is elastically deflectable from its neutral position, about a rotational axis situated perpendicularly to a substrate surface and so that it is capable of rotary oscillation;

wherein the first spiral spring device includes a first bend at its anchoring region with the anchoring device, the second spiral spring device includes a second bend at its anchoring region with the anchoring device, the first bend bending away from the first and second spiral spring devices towards a first portion of the anchoring region, the second bend bending away from the first and second spiral spring devices towards a second portion of the anchoring region.

2. The rotation-rate sensor of claim 1, wherein the bend at the anchoring region of the first spiral spring device is configured to enable radial length equalization.

3. The rotation-rate sensor of claim 1, wherein the first spiral spring device includes a bent region at its connection to the centrifugal mass.

4. The rotation-rate sensor of claim 1, wherein the anchoring region of the first spiral spring device is provided outside a center of the rotary oscillation.

5. The rotation-rate sensor of claim 1, further comprising:

a third spiral spring device connecting the centrifugal mass to the anchoring device;

wherein the first and third spiral spring devices are positioned in a V shape such that legs of the V shape spread open in a direction of the centrifugal mass at an opening angle.

6. The rotation-rate sensor of claim 5, wherein the opening angle is selected such that a natural frequency of the rotation-rate sensor is less about the axis of rotation situated perpendicularly to the substrate surface than each natural frequency of the rotation rate sensor about an axis of rotation situated in parallel to the substrate surface.

7. The rotation-rate sensor of claim 1, further comprising:

three additional spiral spring devices, wherein the first and the three additional spiral spring devices are positioned such that they essentially form an X shape.

8. The rotation-rate sensor of claim 7, further comprising:

at least one spring device in addition to the spiral spring devices forming an X shape, the additional spring device connecting the centrifugal mass to the anchoring device.

9. The rotation-rate sensor of claim 1, wherein the rotation-rate sensor is produced using one of a silicon surface micromechanics process and another micromechanics process.

10. The rotation-rate sensor of claim 1, wherein at least one of:

the anchoring device is fixedly connected to the substrate, or the anchoring device is positioned in a movable manner relative to the substrate.