Quartz resonator with plasma etched tethers for stress isolation from the mounting contacts

Patent metadata

Field	Value
Publication number	US-9879997-B1
Application number	US-201414547057-A
Country	US
Kind code	B1
Filing date	Nov 18, 2014
Priority date	Nov 19, 2013
Publication date	Jan 30, 2018
Grant date	Jan 30, 2018

Abstract

A resonator assembly includes a semiconductor substrate; a resonator gyroscope, the resonator gyroscope including a first resonator formed in a layer of a first material; and an oscillator on the semiconductor substrate, the oscillator including a second resonator formed of a second material. The second resonator is disposed in a cavity, the cavity comprising a first recess in the layer of a first material with the edges of the first recess being attached to the substrate, or the cavity comprising a second recess in the substrate and the edges of the second recess being attached to the layer of a first material.

First claim

What is claimed is:

1. A resonator assembly comprising:
a first substrate;
a resonator gyroscope disposed on or adjacent said first substrate, the resonator gyroscope including a first resonator formed in a layer of a first material; and
an oscillator disposed on or in the substrate, the oscillator being associated with and electrically coupled to a second resonator, the second resonator having electrodes disposed on opposing surfaces of a second substrate formed of a second material;
the second resonator being supported from said substrate in a cantilevered fashion by springs or tethers formed of said second material, the springs or tethers having electrical conductors disposed thereon which ohmically couple the electrodes of the second resonator with the oscillator;
wherein the first resonator comprises a central mounting stem, the central mounting stem having a cavity located therein, and wherein the second resonator is disposed within said cavity.

2. The resonator assembly of claim 1 , further comprising a common heater centrally located beneath the first and second resonators.

3. The assembly of claim 1 , wherein the first material is silicon and the second material is quartz.

4. The resonator assembly of claim 3 , wherein the second resonator is a SC-cut shear-mode quartz resonator.

5. The resonator assembly of claim 3 , wherein the quartz resonator has electrodes comprising gold.

6. The resonator assembly of claim 1 , wherein the cavity includes vent ports.

7. The resonator assembly of claim 6 , in which the two resonators are vacuum sealed in a common housing.

8. The resonator assembly of claim 7 in which heaters are placed on the outside surface of the common housing.

9. The resonator assembly of claim 1 wherein the first substrate is a semiconductor substrate.

10. The resonator assembly of claim 9 wherein springs or tethers are elongated, following a smooth curve from a point of joining with a main body portion of the second material to distill ends thereof, the distill ends having contacts coupled with or made from the electrical conductors disposed on said springs or tethers, said contacts providing a sole means of supporting the second resonator from said first substrate.

11. The resonator assembly of claim 9 wherein springs or tethers are elongated, conformally following a smooth curve with a main body portion of the second material to distill ends thereof.

12. The resonator assembly of claim 11 wherein said springs or tethers are defined by plasma etching said second material.

13. The resonator assembly of claim 1 wherein springs or tethers are formed of said second material integrally with the second material upon which said electrodes are disposed on opposing surfaces thereof.

14. The resonator assembly of claim 1 wherein said springs or tethers are defined by plasma etching said second material.

15. A resonator assembly, the resonator assembly comprising:
a substrate;
a gyroscope supported by said substrate;
an oscillator resonator having electrodes disposed on opposing surfaces of a layer of material, the layer of material having a generally rounded shape, the oscillator resonator also having elongate springs or tethers, the elongate springs or tethers being formed from said layer of material, an exterior surface of each of the springs or tethers continuing to follow said rounded shape along a major portion of a length of each spring or tether, the elongate springs or tethers having conductors formed thereon, the conductors also being formed on the layer of material to make electrical contact with said electrodes disposed on opposing surfaces of the layer of material, said conductors also making electrical contact with contacts formed on distal ends of said elongate springs or tethers, and
means for attaching the oscillator resonator to the substrate at the contacts formed on the distal ends of said elongate springs or tethers of the oscillator resonator.

16. The apparatus of claim 15 , wherein the electrodes of the oscillator resonator are supported in a cantilevered fashion above said substrate by said layer of material including by said elongate springs or tethers formed from said layer of material.

17. The apparatus of claim 16 wherein said layer of material is a layer of quartz material and wherein the springs or tethers are integral with the quartz material upon which said electrodes are disposed on opposing surfaces thereof.

18. The apparatus of claim 15 wherein the springs or tethers are elongated, following a smooth curve from a point of joining with a main body portion of the quartz material to a distill ends thereof, the distill ends having said contacts coupled with or made from the electrical conductors disposed on said springs or tethers, said contacts providing a sole means of supporting the second resonator from said substrate.

19. An apparatus comprising:
a quartz substrate having at least one via therein, the quartz substrate having a generally rounded shape with integral springs or tethers also defined in the quartz substrate, an exterior surface of each of the springs or tethers continuing to follow said rounded shape along a major portion of a length of each spring or tether;
connection pads disposed at distal ends of the springs or tethers on a common side thereof;
resonator electrodes disposed on two opposing sides of the quartz substrate;
connection means connecting the connection pads on distal ends of the springs or tethers with said resonator electrodes on two opposing sides of a quartz substrate, the connection means including one connection from one of the connection pads on one distal end of the one of the springs or tethers to one of the resonator electrodes using said via to traverse from one major surface of the shaped quartz substrate to the opposing major surface thereof; and
a second substrate having an associated oscillator, support for a DRG resonator, and pads for mating with the connection pads disposed on distal ends of said springs or tethers.

20. The apparatus of claim 19 wherein the springs or tethers in the quartz substrate define rounded shapes without sharp corners where said springs or tethers attach to a major portion of the quartz substrate to thereby provide stress relief at said rounded shapes where said springs or tethers attach to the major portion of the quartz substrate.

21. The apparatus of claim 19 wherein said major portion of the length of said springs or tethers define a radius of a circle.

22. The apparatus of claim 21 wherein all of said apparatus is disposed within said circle.

23. The apparatus of claim 22 wherein said resonator electrodes are formed on mesa regions defined on said two opposing sides of a quartz substrate.

24. The apparatus of claim 19 wherein said resonator electrodes are each formed with an elliptical shape when viewed in a plan view thereof.

25. The apparatus of claim 19 wherein the second substrate supports and is coupled with said DRG resonator.

26. The apparatus of claim 25 wherein said pads for mating with the connection pads disposed on distal ends of said springs or tethers are electrically coupled, in use, with said oscillator.

27. The apparatus of claim 19 wherein the gyroscope includes a gyroscope resonator formed in a layer of a material different than the material of said oscillator resonator.

28. A connection apparatus f

Assignees

• Hrl Lab Llc

Inventors

• Kubena Randall L
• Yong Yook-Kong
• Kirby Deborah J
• Chang David T

Classifications

• H03H9/19

  consisting of quartz · CPC title

• G01C19/5677 Primary

  of essentially two-dimensional [2D] vibrators, e.g. ring-shaped vibrators · CPC title

• G01C19/5684 Primary

  the devices involving a micromechanical structure · CPC title