Micromechanical component and method for manufacturing a micromechanical component

• US 9,097,736 B2
• Filed: 10/24/2012
• Issued: 08/04/2015
• Est. Priority Date: 10/27/2011
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Classen, Johannes, Kaelberer, Arnd, Tebje, Lars
• Primary Examiner(s): Kwok, Helen
• Application Number:
  US13/658,949
• Publication Number:
  US 20130104654A1
• Time in Patent Office: 1,014 Days
• Field of Search: 735/143.2, 735/143.6, 735/143.8, 735/10, 735/141.8, 735/142.4
• US Class Current: 1/1
• CPC Class Codes: B81B 2201/025 Inertial sensors not provided for in B81B2201/0235 - B81B2201/0242
• CPC Class Codes: B81B 3/0072 For controlling internal stress or strain in moving or flexible elements, e.g. stress compensating layers
• 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 2015/0805 being provided with a particular type of spring-mass-system for defining the displacement of a seismic mass due to an external acceleration
• CPC Class Codes: Y10T 29/49155 Manufacturing circuit on or in base

Abstract

A micromechanical component includes: a substrate; a seismic weight joined to the substrate at a first suspension mount; at least one first electrode for measuring a motion of the seismic weight in a first direction, the first electrode being joined to the substrate at a second suspension mount; and at least one second electrode for measuring a motion of the seismic weight in a second direction different from the first direction, the second electrode being joined to the substrate at a third suspension mount. The first electrode is mechanically connected to the second suspension mount with the aid of a support arm and set apart from the second suspension mount.

Claims

1. A micromechanical component, comprising:

a substrate;

a seismic weight joined to the substrate at a first suspension mount;

at least one first electrode for measuring a motion of the seismic weight in a first direction, the first electrode being joined to the substrate at a second suspension mount; and

at least one second electrode for measuring a motion of the seismic weight in a second direction different from the first direction, the second electrode being joined to the substrate at a third suspension mount;

wherein the first electrode is set apart from the second suspension mount and mechanically connected to the second suspension mount with the aid of a support arm; and

wherein a distance between the first electrode and the second suspension mount is greater than a distance between the first suspension mount and the second suspension mount.

2. The micromechanical component as recited in claim 1, wherein multiple first electrodes and corresponding multiple second suspension mounts are provided, and the second suspension mounts associated with the first electrodes are situated symmetrically about the first suspension mount.

3. The micromechanical component as recited in claim 2, wherein the support arm includes support-arm branches set apart from one another, and wherein at least one first electrode is situated at each support-arm branch.

4. The micromechanical component as recited in claim 1, wherein the second electrode is set apart from the third suspension mount and mechanically connected to the third suspension mount with the aid of a further support arm.

5. The micromechanical component as recited in claim 4, wherein the seismic weight has a recess, and wherein the first and the second suspension mount are situated inside the recess.

6. The micromechanical component as recited in claim 5, wherein:

the seismic weight is joined to the first suspension mount by two torsional bending springs extending from the first suspension mount to respective sides of the recess lying diametrically opposed to each other; and

in a resting position of the seismic weight in which the seismic weight is not deflected, the support arm is parallel to the torsional bending springs.

7. The micromechanical component as recited in claim 1, wherein:

the first and second suspension mounts are situated in a central region of the seismic weight; and

the central region has a maximum dimension of 60% of a dimension of the seismic weight in a selected direction.

8. The micromechanical component as recited in claim 6, wherein the third suspension mount is situated inside of the recess, and the further support arm is positioned perpendicular to the support arm.

9. The micromechanical component as recited in claim 1, wherein:

multiple first electrodes are provided;

a first portion of each of the first electrodes is fixed in a first plane;

a second portion of each of the first electrodes is fixed in a second plane; and

the first and second planes are positioned one above the other.

10. The micromechanical component as recited in claim 9, wherein the micromechanical component is formed as an acceleration sensor.

11. A method for manufacturing a micromechanical component, comprising:

producing a seismic weight on a substrate, the seismic weight being joined to the substrate by a first suspension mount;

producing at least one first electrode for measuring a motion of the seismic weight in a first direction, the first electrode being joined to the substrate at a second suspension mount; and

producing at least one second electrode for measuring a motion of the seismic weight in a second direction different from the first direction, the second electrode being joined to the substrate at a third suspension mount;

wherein the first electrode is mechanically connected to the second suspension mount by a support arm, so that the first electrode is set apart from the second suspension mount; and

wherein a distance between the first electrode and the second suspension mount is greater than a distance between the first suspension mount and the second suspension mount.