Strain decoupled sensor

Patent metadata

Field	Value
Publication number	US-10422642-B2
Application number	US-201715399949-A
Country	US
Kind code	B2
Filing date	Jan 6, 2017
Priority date	Jan 5, 2012
Publication date	Sep 24, 2019
Grant date	Sep 24, 2019

Abstract

A sensor comprises a substrate 16 and a sensor element 20 anchored to the substrate 16, the substrate 16 and sensor element 20 being of dissimilar materials and having different coefficients of thermal expansion, the sensor element 20 and substrate 16 each having a generally planar face arranged substantially parallel to one another, the sensor further comprising a spacer 26, the spacer 26 being located so as to space at least part of the sensor element 20 from at least part of the substrate 16, wherein the spacer 26 is of considerably smaller area than the area of the smaller of face of the substrate 16 and that of the sensor element 20.

First claim

What is claimed is:

1. A vibratory ring gyroscope, comprising:
a substrate;
a ring shaped resonator;
a magnet assembly comprising a sensor element anchored to the substrate, the substrate and sensor element being of dissimilar materials and having different coefficients of thermal expansion, the sensor element and substrate each having a generally planar face arranged substantially parallel to one another, and
a single spacer whereby the sensor element is anchored upon the substrate, the spacer being located so as to space at least part of the sensor element from at least part of the substrate,
wherein a face of the spacer is of area less than half of the area of the substrate and less than half of the area of the sensor element.

2. A vibratory ring gyroscope according to claim 1 , wherein the spacer is formed integrally with one or other of the sensor element and the substrate.

3. A vibratory ring gyroscope according to claim 2 , wherein the spacer is bonded to the other of the sensor element and the substrate.

4. A vibratory ring gyroscope according to claim 1 , wherein the spacer is formed integrally with the substrate.

5. A vibratory ring gyroscope according to claim 4 , wherein the spacer is defined by a projection, protruding from the surrounding part of the substrate.

6. A vibratory ring gyroscope according to claim 5 , wherein a cavity is formed in the face of the substrate, the spacer protruding from the base of the cavity.

7. A vibratory ring gyroscope according to claim 6 , wherein the projection is located at the centre of the cavity.

8. A vibratory ring gyroscope according to claim 7 , wherein the cavity is of annular form.

9. A vibratory ring gyroscope according to claim 5 , wherein the projection is of generally cylindrical shape.

10. A vibratory ring gyroscope according to claim 1 , wherein the spacer is of area less than 30 percent of the area of the smaller of the substrate and the sensor element.

11. A vibratory ring gyroscope according to claim 1 , wherein the spacer spaces the substrate and sensor element apart by a distance comprising at least 30 microns.

12. A vibratory ring gyroscope according to claim 1 , wherein the sensor element is a lower pole piece of the magnet assembly.

13. A vibratory ring gyroscope according to claim 12 , wherein the magnet assembly further comprises:
an upper pole piece; and
a magnet located between the upper pole piece and the lower pole piece.

14. A vibratory ring gyroscope according to claim 1 , wherein the resonator is mounted upon the substrate independently from the spacer.

Assignees

• Atlantic Inertial Systems Ltd

Inventors

• Fell Christopher Paul

Classifications

• G01C19/5684

  the devices involving a micromechanical structure · CPC title

• G01C19/5783 Primary

  Mountings or housings not specific to any of the devices covered by groups G01C19/5607 - G01C19/5719 · CPC title

• B81B2201/0242

  Gyroscopes · CPC title

• B81B7/0048

  between the MEMS die and the substrate · CPC title

• B81B3/0021

  Transducers for transforming electrical into mechanical energy or vice versa (dynamo-electric machines H02K99/00; electrostatic machines H02N1/00; piezoelectric devices H10N30/00) · CPC title