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The disclosure is directed to a method for processing quartz used in fabricating crystal resonators such that transient frequency change of resonators exposed to pulse irradiation is virtually eliminated. The method involves heating the crystal quartz in a hydrogen-free atmosphere while simultaneously applying an electric field in the Z-axis direction of the crystal. The electric field is maintained during the cool-down phase of the process.

InventorJames Claude King
Original AssigneeBliley Electric Company
Current U.S. Classification310/311; 117/3; 117/943
International Classification: H01L 4110

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Citations

Cited PatentFiling dateIssue dateOriginal AssigneeTitle
US2437913Dec 15, 1944Mar 16, 1948QUARTZ OSCILLATOR PLATE
US2898243Mar 14, 1958Aug 4, 1959METHOD OF CHANGING THE RESONANT FREQUENCY OF A QUARTZ CRYSTAL
US3113224Jun 21, 1961Dec 3, 1963UNTREATED
US3263103Jan 3, 1963Jul 26, 1966RADIATION INSENSITIVE QUARTZ CRYSTAL DEVICES
US3337439Nov 9, 1964Aug 22, 1967ELECTROLYTIC TREATMENT OF QUARTZ

Referenced by

Citing PatentFiling dateIssue dateOriginal AssigneeTitle
US4255228Jan 5, 1979Mar 10, 1981The United States of America as represented by the Secretary of the ArmyMethod of growing quartz
US4274907May 8, 1980Jun 23, 1981The United States of America as represented by the Secretary of the ArmyMethod of chemically polishing a doubly rotated quartz plate
US4311938May 9, 1980Jan 19, 1982The United States of America as represented by the Secretary of the ArmyMethod of sweeping quartz
US4725754Jun 22, 1987Feb 16, 1988The United States of America as represented by the Secretary of the ArmyMethod of making a low aging piezoelectric resonator
US5167079Jul 9, 1991Dec 1, 1992Precision Quartz Products, Inc.Apparatus and method for cleaning piezoelectric crystal components
US6982430May 27, 2004Jan 3, 2006The United States of America as represented by the Secretary of the NavyRadiation case
US7878205Oct 5, 2007Feb 1, 2011National Institute for Materials Science
Nidek Co., Ltd.
Manufacturing method for QPM wavelength converter elements, QPM wavelength converter element, and medical laser apparatus using it

Claims

1. A method of processing crystal quartz material comprising the steps of,

maintaining the quartz at thermal equilibrium at a temperature of 500.degree.C to 570.degree.C in an atmosphere substantially free of hydrogen, while
applying an electric field along theh Z-axis of the crystal quartz between anode and cathode electrodes of a strength from 1 to 5 kV/cm for a period of 72 to 120 hours, and
maintaining said electric field while said crystal is cooled.

2. The method of claim 1 wherein said temperature equilibrium is 550.degree.C and said electric field is 2 kV/cm.

3. The method of claim 1 further comprising the subsequent step of,

removing from 10 to 40 thousandths of an inch of the crystal perpendicular to the Z axis from the surface adjacent to said cathode electrode, and then
repeating the steps of claim 1.

4. The method of claim 3 further comprising the subsequent step of,

removing from 10 to 40 thousandths of an inch of the crystal perpendicular to the Z-axis from the surface adjacent to said cathode electrode, and then
repeating the steps of claim 1.

5. The method of claim 1 wherein the atmosphere is a dry gas selected from the group consisting of helium neon, argon and nitrogen.

6. The method of claim 1 wherein said crystal quartz is natural quartz.

7. The method of claim 1 wherein said crystal quartz is synthetic quartz.

8. The method of claim 7 wherein said synthetic quartz is of homogeneous Z-growth material.

9. The method of claim 1 further comprising the step of

subjecting the crystal quartz to ionizing radiation of 10.sup.5 to 10.sup.6 rad simultaneously to said step of applying an electric field to said crystal quartz.

10. A method of processing crystal quartz material comprising the steps of

maintaining the quartz at thermal equilibrium in the beta phase at a temperature of 700.degree. to 900.degree.C in an atmosphere substantially free of hydrogen while
applying an electric field between anode and cathode electrodes along the Z-axis of the crystal quartz of a strength from 1 to 5 kV/cm for a period of 6 to 12 hours, and
cooling said quartz while maintaining said electric field and applying a compression stress which induces a strain no less than 10.sup.-.sup.4 in the X direction of said crystal as the quartz cools from the beta phase through 573.degree.C to the alpha phase.

11. The method of claim 10 wherein said thermal equilibrium temperature is 800.degree.C and wherein said electric field strength is 2 kV/cm.

12. A method of processing crystal quartz material comprising the steps of

maintaining the quartz at thermal equilibrium in the beta phase at a temperature of 700.degree. to 900.degree.C in an atmosphere substantially free of hydrogen, while
applying an electric field between anode and cathode electrodes along the Z axis of the crystal quartz of a strength from 1 to 5 kV/cm for a period of 6 to 12 hours, and
cooling said quartz while maintaining said electric field along the Z axis and applying an electric field along the X axis sufficient to create a strain no less than 10.sup.-.sup.4 as the quartz cools from the beta phase through 573.degree.C to the alpha phase.

13. The method of claim 1 wherein said electrodes are thin platinum sheets of 99.9 to 99.99% purity.

14. A quartz crystal for use in a crystal resonator comprising a quartz crystal which has been treated by the steps of,

maintaining the quartz at thermal equilibrium at a temperature of 500.degree.C to 570.degree.C in an atmosphere substantially free of hydrogen, while
applying an electric field between anode and cathode electrodes along the Z axis of the crystal quartz of a strength from 1 to 5 kV/cm for a period of 72 to 120 hours, and
maintaining said electric field while said crystal is cooled.

Drawings