US4070203A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for stripping photolacquers
Assignee: Merck Patent GmbH
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Filing: 1975-11-13
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Granted: 1978-01-24
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Expires: 1995-11-13
Abstract
Abstract Hardened photolacquer on semi-conductors and integrated circuits for etching purposes are stripped therefrom employing, preferably at a temperature above 75 DEG C., a stripping composition consisting essentially of 20-50 weight percent of at least one alkylbenzenesulfonic acid of 12-20 carbon, and 80-50 weight percent of a chlorine-free, aromatic hydrocarbon having a boiling point above 150 DEG C.
Inventors
- 👤 Karl Heinz Neisius
- 👤 Wilhelm Baumer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 03:21
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/26; G03F7/42; G03F7/422; G03F7/426; H; H10; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/286; H10P50/287
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
96 words
In a method of stripping a hardened photolacquer etching mask from the surface of an etched electronic component substrate coated therewith by contacting the surface of the substrate with a stripping agent for the photolacquer which is free of metal ions, dust and high molecular weight and resinous impurities, the improvement wherein the stripping agent is a substantially impurity-free mixture of 20-50 weight percent of at least one alkylbenzenesulfonic acid of 12-20 carbon atoms and the remaining 80-50 weight percent of the mixture being a chlorine-free, aromatic hydrocarbon solvent having a boiling point above 150° C.
Claim 2
Dependent Claim
96 words
In a method of stripping a hardened photolacquer etching mask from the surface of an etched electronic component substrate coated therewith by contacting the surface of the substrate with a stripping agent for the photolacquer which is free of metal ions, dust and high molecular weight and resinous impurities, the improvement wherein the stripping agent is a substantially impurity-free mixture of 20-50 weight percent of at least one alkylbenzenesulfonic acid of 12-20 carbon atoms and the remaining 80-50 weight percent of the mixture being a chlorine-free, aromatic hydrocarbon solvent having a boiling point above 150° C.
Claim 3
Dependent Claim
22 words
A method according to claim 1 wherein the alkylbenzenesulfonic acid is one or more of octylbenzenesulfonic acid, nonylbenzenesulfonic acid or dodecylbenzenesulfonic acid.
Claim 4
Dependent Claim
20 words
A method according to claim 1 wherein the aromatic hydrocarbon solvent is one or more alkylbenzenes of 9-18 carbon atoms.
Claim 5
Dependent Claim
22 words
A method according to claim 1 wherein the aromatic hydrocarbon is a mixture of alkylbenzenes having a boiling range of 200°-260° C.
Claim 6
Dependent Claim
70 words
A method according to claim 1 wherein the stripping agent is a mixture consisting of 30-40 weight percent of at least one alkylbenzenesulfonic acid of 14-18 carbon atoms and 70-60 weight percent of an aromatic hydrocarbon solvent boiling in the range of 200°-260° C. and consisting, by weight, of 80-99% aromatics and the remainder, up to 19% aliphatic or cycloaliphatic hydrocarbons and no more than 2% of olefinic unsaturated hydrocarbons.
Claim 7
Dependent Claim
36 words
A method according to claim 1 wherein the stripping agent is a mixture consisting essentially of 30-40% of octylbenzenesulfonic acid, nonylbenzenesulfonic acid or dodecylbenzenesulfonic acid and 70-60% of one or more alkylbenzenes of 9-18 carbon atoms.
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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) | 1981-01-23 | 1981-07-25 | 1982-01-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-23 | 1985-07-25 | 1986-01-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-23 | 1989-07-25 | 1990-01-24 | $7700.00 | Window Closed / Lapsed |