US3914836A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for processing quartz crystal resonators
Assignee: United States Department of the Army
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Filing: 1974-06-21
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Granted: 1975-10-28
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Expires: 1994-06-21
Abstract
Abstract Precision quartz crystal resonators are processed in a high vacuum system in which all processing steps are performed in the same vacuum system without venting between stages. The processing steps include cleaning the resonator parts to remove contaminants from the surface, baking the resonator parts at temperatures up to 450*C to further remove adsorbed and absorbed contaminants, plating electrodes onto the crystal resonator, and sealing the resonator parts.
Inventors
- 👤 Erich Hafner
- 👤 John R Vig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 08:17
CPC Classifications
H; H03; H03H; H03H3/00; H03H3/007; H03H3/02; Y; Y10; Y10S; Y10S29/00; Y10S29/044; Y10T; Y10T29/00; Y10T29/42
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
104 words
Method of processing precision quartz crystal resonators in a high vacuum system in which all processing steps are performed in the same vacuum system without venting between steps, and wherein said processing steps are each carried out in separate vacuum chambers, said chambers being interconnected to prevent exposure of the resonator parts to contaminating atmospheres during transfer between chambers, said processing steps including: a. cleaning the resonator parts to remove contaminants from the surface, b. baking the resonator parts at temperatures up to 450*C to further remove adsorbed and absorbed contaminants, c. depositing electrodes onto the crystal resonator, and d. sealing the resonator parts.
Claim 2
Dependent Claim
104 words
Method of processing precision quartz crystal resonators in a high vacuum system in which all processing steps are performed in the same vacuum system without venting between steps, and wherein said processing steps are each carried out in separate vacuum chambers, said chambers being interconnected to prevent exposure of the resonator parts to contaminating atmospheres during transfer between chambers, said processing steps including: a. cleaning the resonator parts to remove contaminants from the surface, b. baking the resonator parts at temperatures up to 450*C to further remove adsorbed and absorbed contaminants, c. depositing electrodes onto the crystal resonator, and d. sealing the resonator parts.
Claim 3
Dependent Claim
15 words
Method according to claim 1 wherein the cleaning in step (a) is by ion bombardment.
Claim 4
Dependent Claim
27 words
Method according to claim 1 wherein the cleaning in step (a) is by irradiation with ultraviolet light in the presence of a small partial pressure of oxygen.
Claim 5
Dependent Claim
16 words
Method according to claim 1 wherein the electrode deposition in step (c) is by Thermal evaporation.
Claim 6
Dependent Claim
27 words
Method according to claim 1 wherein the electrode deposition in step (c) is by simultaneous plating onto the two sides of the resonator at near equal rates.
Claim 7
Dependent Claim
38 words
Method according to claim 1 wherein in the electrode deposition in step (c), a loading and outgassing chamber is used for the changing and outgassing of the evaporation sources and the replenishing and outgassing of the electrode material.
Claim 8
Dependent Claim
23 words
Method according to claim 1 wherein the electrode deposition in step (c) is followed by ion bombardment for adjustment of the final frequency.
Claim 9
Dependent Claim
23 words
Method according to claim 1 wherein the electrode deposition in step (c) is followed by laser trimming for adjustment of the final frequency.
Claim 10
Dependent Claim
24 words
Method according to claim 1 wherein the sealing is carried out at pressures variable up to 5 tons and at temperatures up to 400*C.
Claim 11
Dependent Claim
17 words
Method according to claim 1 wherein the vacuum chambers are maintained clean by irradiation with ultraviolet light.
Claim 12
Dependent Claim
18 words
Method according to claim 1 wherein sealing is achieved by pressing two near atomically cleaned metal surfaces together.
Claim 13
Dependent Claim
20 words
Method according to claim 1 wherein the sealing is achieved with a metal O-ring between two near atomically clean surfaces.
Claim 14
Dependent Claim
17 words
Method according to claim 11 wherein heat is applied to the sealing surfaces during the sealing step.
Claim 15
Dependent Claim
17 words
Method according to claim 12 wherein heat is applied to the sealing surfaces during the sealing step.
Claim 16
Dependent Claim
70 words
Method according to claim 1 wherein sealing of the resonator parts in step (d) is accomplished by positioning a metal O-ring between a pair of rigorously cleaned, unmetallized aluminum surfaces of the resonator enclosure, said metal O-ring being selected from the group consisting of aluminum, iron, niobium, copper, and titanium and wherein a force up to five tons at a temperature up to 400*C is applied to effect the seal.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-10-27 | 1979-04-28 | 1979-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-27 | 1983-04-28 | 1983-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-27 | 1987-04-28 | 1987-10-28 | $7700.00 | Window Closed / Lapsed |