Rounded and curved integrated tethers for quartz resonators

• US 9,991,863 B1
• Filed: 04/07/2015
• Issued: 06/05/2018
• Est. Priority Date: 04/08/2014
• Status: Active Grant

• Current Assignee: HRL Laboratories LLC (The Boeing Co.)
• Original Assignee: HRL Laboratories LLC (The Boeing Co.)
• Inventors: Kubena, Randall L., Kirby, Deborah J., Chang, David T.
• Primary Examiner(s): San Martin, J.
• Application Number:
  US14/680,902
• Time in Patent Office: 1,155 Days
• Field of Search: 310339
• CPC Class Codes: H03H 9/02062 Details relating to the vibration mode
• CPC Class Codes: H03H 9/0514 consisting of mounting pads or bumps
• CPC Class Codes: H03H 9/19 consisting of quartz

Abstract

A piezoelectric quartz shear-mode resonator includes plasma etched quartz tethers, each including a mount. The tethers are for mounting the resonator to a semiconductor substrate for the purpose of isolating the thermally-induced stress from the mounts from the active resonating region, wherein the quartz tethers have rounded corners.

Claims

1. A piezoelectric quartz shear-mode resonator comprising quartz isolation tethers, each comprising a mount for mounting to a semiconductor substrate, wherein the quartz tethers each have at least one rounded corner.

2. The quartz shear-mode resonator of claim 1 wherein:

the respective mounts are coupled to corresponding first sections of the isolation tethers by rounded outer corners and inner corners;

the respective first sections are coupled through a right angle to corresponding second sections by a rounded outer corner and a rounded inner corner;

the respective second sections are coupled through a right angle to corresponding third sections by rounded outer corners and inner corners; and

the respective third sections are coupled to the resonator by an rounded inner corner;

wherein

the respective isolation tethers form a straight line between the inner corners of the third sections.

3. The quartz shear-mode resonator of claim 1 wherein:

the respective mounts are coupled to corresponding first sections by rounded outer corners and inner corners;

the respective first sections are coupled through a right angle to corresponding second sections by a rounded outer corner and a rounded inner corner; and

the respective second sections are coupled through a right angle to corresponding third sections by rounded outer corners and inner corners; and

the respective third sections are coupled to the resonator by a rounded inner corner;

wherein

the respective isolation tethers form a continuous curve between the rounded outer and inner corners of the second sections.

4. The quartz shear-mode resonator of claim 1 wherein:

the respective mounts are coupled to corresponding first sections by rounded outer corners and inner corners;

the respective first sections are coupled through a right angle to corresponding second sections by a rounded outer corner and a rounded inner corner;

the respective second sections are coupled through right angles to corresponding third sections by rounded outer and inner corners;

the respective third sections are coupled to the resonator by a rounded inner corner;

wherein

the respective isolation tethers form a continuous curve between the inner corners of the third section.

5. The quartz shear-mode resonator of claim 1 wherein:

the resonator is round or elliptical;

the isolation tethers are conformally wrapped around the resonator, wherein;

the respective mounts are coupled through a right angle to corresponding first sections of the tethers by rounded outer corners and inner corners;

the respective first sections are coupled through substantially right angles to corresponding quasi-circular second sections by rounded outer corners and inner corners; and

the respective second sections are coupled to the resonator by corresponding rounded inner corners;

wherein

the respective isolation tethers form a substantially straight line between the inner corners of the third section.

6. The quartz shear-mode resonator of claim 1 wherein the quartz isolation tethers are plasma etched.

7. The quartz shear-mode resonator of claim 1 wherein the quartz isolation tethers are rounded or quasi-circular.

8. The quartz shear-mode resonator of claim 1 wherein the lateral width of the quartz isolation tethers is varied along its length.

9. The quartz shear-mode resonator of claim 1 wherein two sets of rounded or quasi-circular isolation tethers are attached to opposite sides of the resonator to minimize vibrational-induced strain in the resonator.

10. The quartz shear-mode resonator of claim 1 wherein the resonator is bonded to the semiconductor substrate with a metallic solder in the mount regions.

11. The quartz shear-mode resonator of claim 1, wherein the quartz shear-mode resonator operates with its fundamental mode in the VHF or UHF ranges.

12. The quartz shear-mode resonator of claim 1 wherein the quartz is composed of AT or SC-cut material.