Inertial sensor and method for manufacturing an inertial sensor

• US 8,850,890 B2
• Filed: 08/03/2011
• Issued: 10/07/2014
• Est. Priority Date: 08/03/2010
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Classen, Johannes
• Primary Examiner(s): CHAPMAN JR, JOHN E
• Application Number:
  US13/197,338
• Publication Number:
  US 20120031186A1
• Time in Patent Office: 1,161 Days
• Field of Search: 735/143.2, 735/143.6, 735/143.7, 438/50
• US Class Current: 73/514.32
• CPC Class Codes: B81B 2201/0242 Gyroscopes
• CPC Class Codes: B81B 2203/0154 Torsion bars
• CPC Class Codes: B81B 3/0045 Improve properties related to angular swinging, e.g. control resonance frequency
• CPC Class Codes: G01P 15/08 with conversion into electric or magnetic values
• CPC Class Codes: G01P 15/0802 Details
• 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
• CPC Class Codes: G01P 2015/086 using a torsional suspension spring

Abstract

An inertial sensor includes a substrate, a mass element, and a detecting device for detecting a movement of the mass element relative to the substrate, the mass element being coupled to the substrate with the aid of a spring device, wherein the spring device has a T-shaped cross-sectional profile. A method for manufacturing an inertial sensor is also disclosed.

Claims

1. An inertial sensor, comprising:

a substrate;

a mass element;

a detecting device configured to detect a movement of the mass element relative to the substrate; and

a spring device, the mass element being coupled to the substrate via the spring device,

wherein the spring device has a T-shaped cross-sectional profile, wherein the mass element includes a recess in which the spring device is situated, and wherein the T-shaped cross-sectional profile has a first portion, closest to the substrate and parallel to the substrate, and a second portion extending from the first portion perpendicularly to the substrate.

2. The inertial sensor as recited in claim 1, wherein the inertial sensor is a micromechanical inertial sensor.

3. The inertial sensor as recited in claim 1, wherein the substrate is a semiconductor substrate.

4. The inertial sensor as recited in claim 1, wherein the mass element has an asymmetrical mass distribution.

5. The inertial sensor as recited in claim 1, wherein the detecting device has at least one detecting electrode situated on the substrate and configured to detect a change in capacitance between the at least one detecting electrode and the mass element.

6. The inertial sensor as recited in claim 1, wherein the spring device and the mass element are integrally formed.

7. The inertial sensor as recited in claim 1, wherein the spring device is suspended on the substrate with the aid of an anchoring element.

8. The inertial sensor as recited in claim 1, wherein:

the first portion is a base,

the second portion is a web, and

the web is joined to the base via a first plurality of subareas of the web and disconnected from the base via a second plurality of subareas of the web.

9. The inertial sensor as recited in claim 8, wherein the second plurality of subareas are recesses in the web.

10. A method of manufacturing an inertial sensor including a spring device having a T-shaped cross-sectional profile, the method comprising:

providing a substrate, a detecting device being situated on the substrate;

depositing a first layer onto the substrate;

structuring the first layer;

depositing an oxide layer onto the structured first layer;

depositing a second layer onto the oxide layer; and

structuring the second layer to form a web which is situated perpendicularly on the first layer.

11. The method as recited in claim 10, wherein the inertial sensor is a micromechanical inertial sensor.

12. The method as recited in claim 10, wherein the substrate is a semiconductor substrate.

13. The method as recited in claim 10, wherein the oxide layer is opened in predetermined areas so that the deposited second layer bonds to the first layer in the predetermined areas.

14. The method as recited in claim 10, wherein the structuring of the first layer includes forming perforations in the first layer.

15. The method as recited in claim 10, wherein a further oxide layer is deposited onto the substrate before the first layer is deposited.

16. The method as recited in claim 15, wherein the oxide layers are removed after the second layer is structured.