US3590468A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Glassy phase method for making pure alumina-to-metal hermetic seals
Assignee: Unisys Corp
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Filing: 1969-02-19
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Granted: 1971-07-06
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Expires: 1989-02-19
Abstract
Abstract A method is described for making reliable hermetic seals between essentially pure alumina and metal. The method comprises applying a metallizing paint to the alumina, sintering the metallizing paint, placing a molybdenum trioxide-manganese dioxide coating on the metallizing layer, sintering the coating, and then bonding the metal to the coated alumina. The metallizing paint comprises molybdenum trioxide and a glass frit in an alcohol suspension containing a nitrocellulose binder, the glass frit constituting from about 2 percent to about 40 percent of the paint by weight.
Inventors
- 👤 Robert W Buck
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 20:19
CPC Classifications
C; C04; C04B; C04B37/00; C04B37/02; C04B37/023; C04B37/025; C03; C03C; C03C8/00; C03C8/24; C04B35/00; C04B35/622; C04B35/626; C04B35/63; C04B35/632; C04B35/636; C04B35/6365; C04B2235/00; C04B2235/65; C04B2235/658; C04B2235/6582; C04B2235/6588; C04B2237/00; C04B2237/02; C04B2237/04; C04B2237/06; C04B2237/068; C04B2237/09; C04B2237/30; C04B2237/32; C04B2237/34; C04B2237/343; C04B2237/50; C04B2237/70; C04B2237/708; C04B2237/72
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
23 words
The method of claim 1 where said paint is applied a plurality of times and said coating is applied a plurality of times.
Claim 2
Dependent Claim
20 words
The method as defined in claim 1 wherein said sintered coating constitutes by weight 80 percent molybdenum and 20 manganese.
Claim 3
Dependent Claim
15 words
The method as defined in claim 1 wherein said paint further includes a nitrocellulose binder.
Claim 4
Dependent Claim
25 words
The method defined in claim 1 wherein the total thickness of said sintered paint and said sintered coating is no greater than about 0.002 inches.
Claim 5
Dependent Claim
25 words
The method defined in claim 1 wherein said paint is sintered at a temperature in the range from about 1000* C. to about 1500* C.
Claim 6
Dependent Claim
13 words
The method defined in claim 1 wherein said paint further includes manganese dioxide.
Claim 7
Dependent Claim
11 words
The method defined in claim 1 wherein said alumina is sapphire.
Claim 8
Dependent Claim
15 words
The method defined in claim 1 wherein said alumina is polycrystalline of relatively high purity.
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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) | 1974-07-05 | 1975-01-04 | 1975-07-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-05 | 1979-01-04 | 1979-07-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-05 | 1983-01-04 | 1983-07-06 | $7700.00 | Window Closed / Lapsed |