Microgyroscope with integrated vibratory element

• US 6,487,907 B1
• Filed: 07/06/2000
• Issued: 12/03/2002
• Est. Priority Date: 07/08/1999
• Status: Expired due to Term

• Current Assignee: National Aeronautics and Space Administration (Government of the United States of America)
• Original Assignee: California Institute of Technology
• Inventors: Rodger, Damien C., Gutierrez, Roman C., Tang, Tony K.
• Primary Examiner(s): KWOK, HELEN C
• Application Number:
  US09/612,325
• Time in Patent Office: 880 Days
• Field of Search: 735/040.2, 735/040.4, 735/041.2, 735/041.4, 735/041.5, 735/142.9, 735/143.5, 735/141.6, 735/143.2
• US Class Current: 73/504.02
• CPC Class Codes: G01C 19/56 Turn-sensitive devices using vibrating masses, e.g. vibratory angular rate sensors based on Coriolis forces

Abstract

A microgyroscope having a suspended vertical post uses the Coriolis force to detect the rotation rate. The microgyroscope consists of a single vertical post which is the rotation rate sensing element. The vertical post is formed from the same silicon wafers as the rest of the microgyroscope. A first portion of the vertical post and the clover-leaf structure are made from a first silicon wafer. A second portion of the vertical post and the baseplate are made from a second silicon wafer. The two portions are then bonded together to from the clover-leaf gyroscope with an integrated post structure.

Claims

1. A microgyroscope comprising:

a first portion of a vertical post and a clover leaf structure formed from a first silicon wafer; and

a second portion of the vertical post and a baseplate formed from a second silicon wafer;

wherein the first portion of the vertical post and the clover leaf structure are bonded to the second portion of the vertical post and the baseplate.

2. The microgyroscope of claim 1, wherein the clover-leaf structure includes a plurality of capacitors positioned proximate the vertical post.

3. The microgyroscope of claim 2, wherein the plurality of capacitors provide an excitation force for the vertical post.

4. The microgyroscope of claim 1, wherein the vertical post is free to move in a z-axis.

5. The microgyroscope of claim 1, wherein the microgyroscope is bonded at approximately a mid-portion of the vertical post.

6. The microgyroscope of claim 1, wherein the bond is a metal-to-metal bonding.

7. A method of constructing a microgyroscope comprising:

forming a first section of the microgyroscope having a first portion of a vertical post and a clover-leaf structure on a first substrate;

forming a second section of the microgyroscope having a second portion of the vertical post and a baseplate on a second substrate; and

bonding the first section of the microgyroscope to the second section of the microgyroscope.

8. The method of claim 7, further comprising forming a single vertical post from the first portion and the second portion.

9. The method of claim 7, wherein the first substrate and the second substrate have similar thermal properties.

10. The method of claim 7, wherein the vertical post is free to move in a z-axis.

11. The method of claim 7, further comprising forming support flanges on the first portion of the vertical post.

12. The method of claim 7, wherein the bonding is a metal-to-metal bonding.

13. A method of constructing a microgyroscope comprising:

forming a first portion of a post and a first plurality of capacitors on a first substrate;

forming a second portion of the post and a baseplate on a second substrate; and

bonding the first portion of the post and the first plurality of capacitors to the second portion of the post and the baseplate.

14. The method of claim 13, further comprising creating the bonding at approximately a mid-point of the microgyroscope.

15. The method of claim 13, further comprising positioning the plurality of capacitors proximate the post.

16. The method of claim 13, wherein the plurality of capacitors form a clover-leaf structure.

17. The method of claim 13, further comprising forming support flanges on the first portion of the post.

18. The method of claim 13, wherein the bonding is a metal-to-metal bonding.