US4040897A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Etchants for glass films on metal substrates
Assignee: Signetics Corp
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Filing: 1976-11-10
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Granted: 1977-08-09
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Expires: 1996-11-10
Abstract
Abstract An aqueous solution for etching a glass layer on a metal (aluminum) substrate without substantial attack on the metal. The solution comprises buffered hydrofluoric acid, sodium chloride, and either (a) a fluorocarbon surfactant capable of forming a protective thin film upon the aluminum, or (b) a 6-hydroxy alcohol (e.g., mannitol or sorbitol).
Inventors
- 👤 II Richard C. Blish
- 👤 Kyle Eugene Lemons
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 11:27
CPC Classifications
C; C03; C03C; C03C15/00; H; H10; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P50/283
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
97 words
In a method of selectively etching a pyralytic glass layer on a metal substrate without substantially attacking the underlying metal, the step of contacting the glass layer with a dilute aqueous etch solution for a sufficient time to etch through the glass layer, said etch solution comprising buffered hydrofluoric acid, sodium chloride at a concentration from about 1% by weight of solution to the point just below saturation where the sodium chloride begins to precipiate, and a fluorocarbon surfactant capable of forming a thin protective film on the metal substrate, said etch solution being diluted with water.
Claim 2
Dependent Claim
97 words
In a method of selectively etching a pyralytic glass layer on a metal substrate without substantially attacking the underlying metal, the step of contacting the glass layer with a dilute aqueous etch solution for a sufficient time to etch through the glass layer, said etch solution comprising buffered hydrofluoric acid, sodium chloride at a concentration from about 1% by weight of solution to the point just below saturation where the sodium chloride begins to precipiate, and a fluorocarbon surfactant capable of forming a thin protective film on the metal substrate, said etch solution being diluted with water.
Claim 3
Dependent Claim
11 words
The method of claim 1 in which the metal is aluminum.
Claim 4
Dependent Claim
26 words
The method of claim 1 in which said surfactant is present at a concentration no greater than about 1000 parts per million parts of etch solution.
Claim 5
Dependent Claim
86 words
In a method of selectively etching a pyrolytic glass layer on a metal substrate without substantially attacking the underlying metal, the step of contacting the glass layer with a dilute aqueous etch solution for a sufficient time to etch through the glass layer, said etch solution comprising buffered hydrofluoric acid, sodium chloride at a concentration from about 1% by weight of solution to the point just below saturation where the sodium chloride begins to precipitate, and a 6-hydroxy alcohol, said etch solution being diluted with water.
Claim 6
Dependent Claim
86 words
In a method of selectively etching a pyrolytic glass layer on a metal substrate without substantially attacking the underlying metal, the step of contacting the glass layer with a dilute aqueous etch solution for a sufficient time to etch through the glass layer, said etch solution comprising buffered hydrofluoric acid, sodium chloride at a concentration from about 1% by weight of solution to the point just below saturation where the sodium chloride begins to precipitate, and a 6-hydroxy alcohol, said etch solution being diluted with water.
Claim 7
Dependent Claim
20 words
The method of claim 4 in which the 6-hydroxy alcohol is selected from the group consisting of mannitol and sorbitol.
Claim 8
Dependent Claim
11 words
The method of claim 4 in which the metal is aluminum.
Claim 9
Dependent Claim
27 words
The method of claim 4 in which said 6-hydroxy alcohol is present at a concentration of no greater than about 4% by weight of the etch solution.
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) | 1980-08-08 | 1981-02-07 | 1981-08-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-08 | 1985-02-07 | 1985-08-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-08 | 1989-02-07 | 1989-08-09 | $7700.00 | Window Closed / Lapsed |