US3718601A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluorescent high alumina substrates
Assignee: AT&T Inc
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Filing: 1971-01-04
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Granted: 1973-02-27
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Expires: 1991-01-04
Abstract
Abstract Substrate-supported circuitry is manufactured by forming circuitry on a high alumina dielectric substrate having a fluorescent character arising from the incorporation of both europium oxide plus yttrium (and/or lanthanum and/or gadolinium) oxide, with the latter oxide (s) acting as a dispersing agent. Testing the integrity of the circuitry is accomplished by irradiating the substrate with ultraviolet light and sensing the passage of any visible light through the circuitry that may occur in the presence of defects.
Inventors
- 👤 A Dentai
- 👤 Uitert Le Grand G Van
- 👤 J Williams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 06:34
CPC Classifications
H; H05; H05K; H05K1/00; H05K1/02; H05K1/0266; H05K1/0269; C; C09; C09K; C09K11/00; C09K11/08; C09K11/77; C09K11/7783; C09K11/7784; H05K1/03; H05K1/0306; H05K2203/00; H05K2203/16; H05K2203/161
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
35 words
The process of claim 1 in which said initial ingredients include a balance which is substantially at least one of the compounds selected from the group consisting of magnesium oxide, silicon dioxide, and calcium oxide.
Claim 2
Dependent Claim
18 words
The process of claim 2 in which said initial ingredients include a balance which is substantially magnesium oxide.
Claim 3
Dependent Claim
23 words
The process of claim 1 in which said intimate mixture consists essentially of 1 part europium and 4 parts yttrium in oxidic form.
Claim 4
Dependent Claim
59 words
The process of claim 1 in which said intimate mixture is formed by calcining the oxides or compounds that will give the oxides, such as carbonates, at a temperature of from 500*C to 800*C for from 1/2 hour to 4 hours, followed by sintering at a temperature of from 1200*C to 1500*C for from 1/2 hour to 6 hours.
Claim 5
Dependent Claim
14 words
The process of claim 5 in which said sintering is done in dry hydrogen.
Claim 6
Dependent Claim
53 words
The process of claim 1 in which said substrate is fired at a temperature of from 1500*C to 1650*C for from 2 to 8 hours in one of the atmospheres selected from the group consisting of air, oxygen, nitrogen, hydrogen, and nitrogen-hydrogen, following the admixing of said intimate mixture with said initial ingredients.
Claim 7
Dependent Claim
26 words
The process of claim 7 in which said nitrogen-hydrogen atmosphere is comprised of from 92 to 98 parts by weight of nitrogen, and the balance hydrogen.
Claim 8
Dependent Claim
9 words
The product made by the process of claim 1.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-02-27 | 1976-08-28 | 1977-02-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-27 | 1980-08-28 | 1981-02-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-27 | 1984-08-28 | 1985-02-27 | $7700.00 | Window Closed / Lapsed |