US3715244A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Chromium film microcircuit mask
Assignee: Corning Glass Works
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Filing: 1971-08-26
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Granted: 1973-02-06
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Expires: 1991-08-26
Abstract
Abstract Improved chromium film glass based articles having a low incidence of film surface defects, and highly hardened extremely scratch and wear resistant quality. The method includes the use of a substantially alkali-free glass substrate upon which is formed a chromium film, after which the composite so formed is heat treated to obtain the desired film hardness and electromagnetic energy reflective quality.
Inventors
- 👤 R Szupillo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 13:38
CPC Classifications
C; C03; C03C; C03C17/00; C03C17/34; C03C17/36; C03C17/3602; C03C17/3605; C03C17/06; C03C17/09; C03C17/3649; C03C17/3657; C03C17/3663; C03C3/00; C03C3/04; C03C3/076; C03C3/089; C03C3/091; C03C3/102; C03C3/108; C03C2217/00; C03C2217/20; C03C2217/25; C03C2217/263; C03C2217/70; C03C2217/78; C03C2218/00; C03C2218/10; C03C2218/15
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
67 words
A mask comprising a substantially alkali-free glass base transparent to photosensitive resist image developing electromagnetic energy, a chromium film on said base, and an oxide interference film on the surface of said chromium film having a density at least sufficient to reduce the reflectivity of the composite of said chromium and interference films to said energy to 10 percent of the reflectivity of a standard aluminum film.
Claim 2
Dependent Claim
67 words
A mask comprising a substantially alkali-free glass base transparent to photosensitive resist image developing electromagnetic energy, a chromium film on said base, and an oxide interference film on the surface of said chromium film having a density at least sufficient to reduce the reflectivity of the composite of said chromium and interference films to said energy to 10 percent of the reflectivity of a standard aluminum film.
Claim 3
Dependent Claim
19 words
The mask of claim 1 wherein said base comprises less than about 0.25 percent by weight of alkali compounds.
Claim 4
Dependent Claim
56 words
The mask of claim 1 wherein said base is formed of material selected from the group of glasses consisting of (a) 50% SiO2, 25% BaO, 10% Al2O3; 15% B2O3; (b) 58% SiO2, 6% BaO, 15% Al2O3, 4% B2O3, 10% CaO, 7% MgO; and (c) 48% SiO2, 7% Al2O3, 13% B2O3, 32% PbO, said percentages by weight.
References Cited (Backward Citations)
US3600243A
Cited
US3526550A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-02-06 | 1976-08-07 | 1977-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-06 | 1980-08-07 | 1981-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-06 | 1984-08-07 | 1985-02-06 | $7700.00 | Window Closed / Lapsed |