Micromechanical component

• US 8,806,940 B2
• Filed: 11/05/2009
• Issued: 08/19/2014
• Est. Priority Date: 11/17/2008
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Classen, Johannes
• Primary Examiner(s): Macchiarolo, Peter
• Assistant Examiner(s): Shah, Samir M
• Application Number:
  US12/613,083
• Publication Number:
  US 20100122578A1
• Time in Patent Office: 1,748 Days
• Field of Search: 735/143.2, 257/E21.211, 438/50
• US Class Current: 73/514.29
• 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

Abstract

A micromechanical component for detecting an acceleration. The component includes a conductive layer having a first and a second electrode and a rotatable flywheel mass in the form of a rocker having a first and a second lever arm. The first lever arm is situated opposite the first electrode, and the second lever arm is situated opposite the second electrode. The first lever arm has a first hole structure having a number of first cut-outs, and the second lever arm has a second hole structure having a number of second cut-outs. The first and the second lever arm have different masses. The component is characterized by the fact that the outer dimensions of the first and second lever arms correspond, and the first hole structure of the first lever arm differs from the second hole structure of the second lever arm. Furthermore, a method for manufacturing such a micromechanical component is provided.

Claims

1. A micromechanical component for detecting an acceleration, comprising:

a substrate;

an insulating layer on the substrate;

a conductive layer on the insulating layer having a first and a second electrode; and

a rotatable flywheel mass in the form of a rocker having a first and a second lever arm, the first lever arm being situated opposite the first electrode, and the second lever arm being situated opposite the second electrode, the first lever arm having a first hole structure having a number of first cut-outs, the second lever arm having a second hole structure having a number of second cut-outs, the first electrode having a third hole structure having a number of third cut-outs, the second electrode having a fourth hole structure having a number of fourth cut-outs, the third hole structure of the first electrode differing from the fourth hole structure of the second electrode, and the first and second lever arms having different masses;

wherein outer dimensions of the first and second lever arms correspond, and the first hole structure of the first lever arm differs from the second hole structure of the second lever arm,

wherein at least one of the first and second electrodes have regions without cut-outs,

wherein at least one of the first and second hole structures have additional cut-outs provided above the regions without cut-outs, the additional cut-outs having smaller dimensions than the corresponding at least one of the first and second cut-outs,

wherein the insulating layer is partially removed such that a residual component of the insulating layer remains in the regions without cut-outs but not in the region with cut-outs.

2. The micromechanical component as recited in claim 1, wherein the first cut-outs of the first hole structure of the first lever arm and the second cut-outs of the second hole structure of the second lever arm have different lateral dimensions.

3. The micromechanical component as recited in claim 1, wherein the third cut-outs of the third hole structure of the first electrode and the fourth cut-outs of the fourth hole structure of the second electrode have different lateral dimensions.

4. The micromechanical component as recited in claim 3, wherein the first cut-outs of the first hole structure of the first lever arm have larger lateral dimensions than the second cut-outs of the second hole structure of the second lever arm, and wherein the fourth cut-outs of the fourth hole structure of the second electrode have larger lateral dimensions than the third cut-outs of the third hole structure of the first electrode.

5. The micromechanical component as recited in claim 1, wherein the third cut-outs of the third hole structure of the first electrode and the fourth cut-outs of the fourth hole structure of the second electrode are respectively arranged in the form of a grid, the first and second electrodes including the regions without cut-outs in the respective grids.

6. The method as recited in claim 1, wherein the only electrode situated opposite the first lever arm is the first electrode and the only electrode situated opposite the second lever arm is the second electrode.

7. A method for manufacturing a micromechanical component for detecting an acceleration, comprising:

providing a substrate;

forming an insulating layer on the substrate;

forming a patterned conductive layer on the insulating layer having a first and a second electrode;

forming a sacrificial layer on the conductive layer;

forming a patterned functional layer on the sacrificial layer for a rotatable flywheel mass in the form of a rocker having a first and a second lever arm, the first lever arm having a first hole structure having a number of first cut-outs, the second lever arm having a second hole structure having a number of second cut-outs, the first electrode having a third hole structure having a number of third cut-outs, the second electrode having a fourth hole structure having a number of fourth cut-outs, the third hole structure of the first electrode differing from the fourth hole structure of the second electrode, and the first and the second lever arm having different masses, wherein at least one of the first and second electrodes have regions without cut-outs,

wherein at least one of the first and second hole structures have additional cut-outs provided above the regions without cut-outs, the additional cut-outs having smaller dimensions than the corresponding at least one of the first and second cut-outs; and

removing the sacrificial layer, the flywheel mass being exposed and the first lever arm being situated opposite the first electrode, and the second lever arm being situated opposite the second electrode;

wherein the patterned functional layer is formed in such a manner that outer dimensions of the first and second lever arms correspond, and the first hole structure of the first lever arm differs from the second hole structure of the second lever arm,

wherein the insulating layer is partially removed such that a residual component of the insulating layer remains in the regions without cut-outs but not in the region with cut-outs.

8. The method as recited in claim 7, wherein the first cut-outs of the first hole structure of the first lever arm and the second cut-outs of the second hole structure of the second lever arm have different lateral dimensions.

9. The method as recited in claim 7, wherein the removal of the sacrificial layer includes introducing an etching medium to the sacrificial layer through the hole structures of the functional layer, the etching medium reaching the insulating layer via the hole structures of the first and second electrodes and the insulating layer being partially removed.