US3791848A
Expired / Lapsed
US
⏱️ 0.0 years remaining
A method of improving the adherence of a metal deposit to a polyimide surface
Assignee: AT&T Inc
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Filing: 1972-05-19
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Granted: 1974-02-12
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Expires: 1992-05-19
Abstract
Abstract An etching composition and a method utilizing such a composition for etching a surface of a polyimide is disclosed. The method comprises exposing the polyimide surface to an etching composition comprising an aqueous solution of a basic compound and ethylene diamine. The ethylene diamine synergistically increases the etching rate of the polyimide. When the ethylene diamine is present in an amount in excess of its degree of solubility the etching of the polyimide results in a frosted or matte finish thereof.
Inventors
- 👤 Angelo M De
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 07:34
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/38; H05K3/381; C; C23; C23C; C23C18/00; C23C18/16; C23C18/18; C23C18/20; C23C18/22
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
17 words
ethylene diamine in an amount in excess of saturation of said aqueous solution, to etch the surface.
Claim 2
Dependent Claim
36 words
The method as defined in claim 1 which further comprises removing a deposit residing on said etched surface, said deposit being one of the group consisting of said etchant, an etchant-polyimide reaction product and mixtures thereof.
Claim 3
Dependent Claim
23 words
The method as defined in claim 1 wherein said ethylene diamine is present in an amount in excess of its degree of solubility.
Claim 4
Dependent Claim
32 words
The method as defined in claim 1 wherein in step (a1) the polyimide surface comprises a polyimide made from the anhydride of pyromellitic acid and 4,4'' diamino-diphenyl ether, having a general formula
Claim 5
Dependent Claim
15 words
The method as defined in claim 1 wherein said basic compound comprises an alkali hydroxide.
Claim 6
Dependent Claim
13 words
The method as defined in claim 1 wherein said basic compound comprises NaOH.
References Cited (Backward Citations)
US2869267A
Cited
US3033703A
Cited
US3179614A
Cited
US3361589A
Cited
GB1160675A
Cited
US3394023A
Cited
FR2016111A1
Cited
US3702285A
Cited
DE2012123A1
Cited
US3686016A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-11 | 1977-08-13 | 1978-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-11 | 1981-08-13 | 1982-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-11 | 1985-08-13 | 1986-02-12 | $7700.00 | Window Closed / Lapsed |