Patent US5292445A successfully refreshed from Google Patents.
US5292445A
Expired / Lapsed
US
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Wet-etch process and composition
Assignee: Texas A&M University System
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Filing: 1992-07-16
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Granted: 1994-03-08
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Expires: 2012-07-16
Abstract
Abstract A wet-etch composition for polyamic acids and partially cured polyamic acids comprising an aqueous solution having a major portion of water, a substituted hydrocarbon solvent and a non-ionic base that is strong enough to deprotonate the polyamic acid or a partially cured polyamic acid in a weight ratio of 0.1-49:49-0.1, with the proviso that the composition contains less than 1.0 percent ionic base. The present invention further provides a process for wet-etching polyamic acids or partially cured polyamic acids.
Inventors
- 👤 Douglas E. Fjare
- 👤 Allyson J. Beuhler
- 👤 Cynthia A. Navar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 10:58
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/26; G03F7/30; G03F7/32; H; H10; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/286; H10P50/287; C; C08; C08J; C08J7/00; C08J7/12; C09; C09K; C09K13/00
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
71 words
A wet-etch composition for selectively etching a polyamic acid of a partially cured polyamic acid comprising an aqueous solution comprising at least 50 weight percent of the total composition of water, a substituted hydrocarbon solvent, and an alkylamine wherein the weight ratio of the substituted hydrocarbon solvent to the alkylamine is about 0.1-49:49-0.1, weight the proviso that the composition contains less than 1.0 weight percent of the total composition ionic base.
Claim 2
Dependent Claim
71 words
A wet-etch composition for selectively etching a polyamic acid of a partially cured polyamic acid comprising an aqueous solution comprising at least 50 weight percent of the total composition of water, a substituted hydrocarbon solvent, and an alkylamine wherein the weight ratio of the substituted hydrocarbon solvent to the alkylamine is about 0.1-49:49-0.1, weight the proviso that the composition contains less than 1.0 weight percent of the total composition ionic base.
Claim 3
Dependent Claim
12 words
The wet-etch composition of claim 1 wherein the hydrocarbon solvent is alcohol.
Claim 4
Dependent Claim
21 words
The composition of claim 2 wherein the alcohol comprises from 1 to 12 carbon atoms and at least one hydroxy group.
Claim 5
Dependent Claim
19 words
The composition of claim 3 wherein the alcohol is selected from the group consisting of methanol, ethanol, and butanol.
Claim 6
Dependent Claim
15 words
The composition of claim 2 wherein the alcohol is a cosolvent of ethanol and butanol.
Claim 7
Dependent Claim
22 words
The composition of claim 1 wherein the alkylamine is selected from the group consisting of triethanolamine, triethylamine, tri(hydroxymethyl)aminomethane, trimethylamine, N,N-diethylethanolamine, and N,N-dimethylethanolamine.
Claim 8
Dependent Claim
12 words
The composition of claim 1 wherein the ionic base is tetramethylammonium hydroxide.
Claim 9
Dependent Claim
9 words
The composition of claim 1 further comprising a surfactant.
Claim 10
Dependent Claim
11 words
The composition of claim 8 wherein the surfactant is polyvinylmethyl ether.
Claim 11
Dependent Claim
29 words
The composition of claim 8 wherein the surfactant is present at a concentration of from about 0.01 weight percent to about 1.0 weight percent of the total wet-etch composition.
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) | 1997-03-07 | 1997-09-06 | 1998-03-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-03-07 | 2001-09-06 | 2002-03-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-03-07 | 2005-09-06 | 2006-03-08 | $7700.00 | Window Closed / Lapsed |