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US3871930A
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Method of etching films made of polyimide based polymers
Assignee: Texas Instruments Inc
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Filing: 1973-12-19
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Granted: 1975-03-18
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Expires: 1993-12-19
Abstract
Abstract Methods for etching films made of polyimide based polymers, including polyamide-imides, are provided, which include dissolving desired portions of the film in a solution of a basic compound in a non-aqueous solvent.
Inventors
- 👤 John G Fish
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 18:03
CPC Classifications
C; C08; C08J; C08J7/00; C08J7/02; C08J7/12; H; H05; H05K; H05K3/00; H05K3/0011; H05K3/0017; H05K3/002; C08J2379/00; C08J2379/04; C08J2379/08; H05K1/00; H05K1/02; H05K1/03; H05K1/0313; H05K1/032; H05K1/0346; H05K2201/00; H05K2201/01; H05K2201/0137; H05K2201/0154; H05K2203/00; H05K2203/07; H05K2203/0779; H05K2203/0783
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
48 words
A PROCESS FOR ETCHING A FILM OF A POLYIMIDE BASED POLYMER WHICH COMPRISES CONTACTING SAID FILM WITH A SOLUTION OF A STRONG ORGANIC BASE IN A NON-AQUEOUS SOLVENT SELECTED FROM THE GROUP CONSISTING OF DIMETHYLSULFOXIDE, SULFOLANE, DIMETHYLFORMAMIDE, HEXAMETHYLPHOSPHORAMIDE, N-METHYL PYRROLIDONE, N, N-DIMENTHYACETAMIDE, N, N-DIMETHYLFORMAMIDE, N, N-DIMETHYLCETAMIDE, AND PYRIDINE.
Claim 2
Dependent Claim
48 words
A PROCESS FOR ETCHING A FILM OF A POLYIMIDE BASED POLYMER WHICH COMPRISES CONTACTING SAID FILM WITH A SOLUTION OF A STRONG ORGANIC BASE IN A NON-AQUEOUS SOLVENT SELECTED FROM THE GROUP CONSISTING OF DIMETHYLSULFOXIDE, SULFOLANE, DIMETHYLFORMAMIDE, HEXAMETHYLPHOSPHORAMIDE, N-METHYL PYRROLIDONE, N, N-DIMENTHYACETAMIDE, N, N-DIMETHYLFORMAMIDE, N, N-DIMETHYLCETAMIDE, AND PYRIDINE.
Claim 3
Dependent Claim
17 words
The process in accordance with claim 1, wherein said strong organic base is a quaternary ammonium hydroxide.
Claim 4
Dependent Claim
18 words
The process in accordance with claim 2, wherein said hydroxide is tetraethylammonium hydroxide and said solvent is dimethylsulfoxide.
Claim 5
Dependent Claim
18 words
The process in accordance with claim 2, wherein said hydroxide is tetraethylammonium hydroxide and said solvent is pyridine.
Claim 6
Dependent Claim
22 words
The process in accordance with claim 3, wherein said hydroxide comprises at least about 30 percent of volume of said etching solution.
Claim 7
Dependent Claim
82 words
A process useful in making a printed circuit comprising: providing a laminate having a first layer of film of polyimide based polymer and a second metal layer; coating said first layer with a photomask; exposing and developing said photomask to form a desired pattern; providing an etching solution comprising a quaternary ammonium hydroxide in a nonaqueous solvent; contacting said first layer with said etching solution to etch the desired portions of said film; and removing the etch reaction product from said laminate.
Claim 8
Dependent Claim
82 words
A process useful in making a printed circuit comprising: providing a laminate having a first layer of film of polyimide based polymer and a second metal layer; coating said first layer with a photomask; exposing and developing said photomask to form a desired pattern; providing an etching solution comprising a quaternary ammonium hydroxide in a nonaqueous solvent; contacting said first layer with said etching solution to etch the desired portions of said film; and removing the etch reaction product from said laminate.
Claim 9
Dependent Claim
31 words
The process in accordance with claim 6, wherein saId solvent is selected from the group consisting of dimethylsulfoxide, sulfolane, dimethylformamide, hexamethylphosphoramide, N-methyl pyrrolidone, N, N-dimethylacetamide, N, N-diethylformamide, N, N-diethylacetamide, and pyridine.
Claim 10
Dependent Claim
18 words
The process in accordance with claim 7, wherein said hydroxide is tetraethylammonium hydroxide and said solvent is dimethylsulfoxide.
Claim 11
Dependent Claim
18 words
The process in accordance with claim 7, wherein said hydroxide is tetraethylammonium hydroxide and said solvent is pyridine.
Claim 12
Dependent Claim
22 words
The process in accordance with claim 8, wherein said hydroxide comprises at least about 30 percent by volume of said etching solution.
Claim 13
Dependent Claim
21 words
The process in accordance with claim 6, wherein said etching solution is stirred while it is in contact with said film.
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) | 1978-03-17 | 1978-09-16 | 1979-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-17 | 1982-09-16 | 1983-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-17 | 1986-09-16 | 1987-03-18 | $7700.00 | Window Closed / Lapsed |