US4353778A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of etching polyimide
Assignee: International Business Machines Corp
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Filing: 1981-09-04
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Granted: 1982-10-12
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Expires: 2001-09-04
Abstract
Abstract In etching openings in polyimide film, the film is first etched with a basic reagent in its uncured or partially cured state to form the desired openings, and thereafter, the film is cured. However, this will leave a layer of disturbed material surrounding the openings which has absorbed some reagent and will not fully cure and, therefore, not provide topography suitable for reliable interconnection and metal adherence. This disturbed material is removed by a second etch in a basic reagent, following additional curing to a sufficient extent to prevent any etching of the polyimide free of absorbed etchant. Thereby, suitable topography and adherence is provided.
Inventors
- 👤 Jonathan P. Fineman
- 👤 Leonard A. Kieny, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:55
CPC Classifications
C; C08; C08J; C08J7/00; C08J7/12; B; B26; B26F; B26F3/00; H; H10; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/286; H10P50/287; C08J2379/00; C08J2379/04; C08J2379/08; H05; H05K; H05K1/00; H05K1/02; H05K1/03; H05K1/0313; H05K1/032; H05K1/0346; H05K3/00; H05K3/0011; H05K3/0017
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
137 words
A method of etching an opening in polyimide material wherein the polymide material is provided in a sufficiently uncured condition to permit etching by a basic etchant, and wherein a selected location of the uncured polyimide is exposed for etching the opening, the improvement comprising: etching said polyimide at the desired location with a basic reagent to provide the opening in the polyimide, some of said etchant being absorbed by a layer of polyimide material surrounding said opening but remaining in place, curing the polyimide to a sufficient extent to prevent any etching of the polyimide free of absorbed etchant, and etching the exposed location a second time with a basic reagent and remove the layer of polyimide having absorbed etchant, whereby the material surrounding the opening after the second etch is rednered free of absorbed etchant.
Claim 2
Independent Claim
137 words
A method of etching an opening in polyimide material wherein the polymide material is provided in a sufficiently uncured condition to permit etching by a basic etchant, and wherein a selected location of the uncured polyimide is exposed for etching the opening, the improvement comprising: etching said polyimide at the desired location with a basic reagent to provide the opening in the polyimide, some of said etchant being absorbed by a layer of polyimide material surrounding said opening but remaining in place, curing the polyimide to a sufficient extent to prevent any etching of the polyimide free of absorbed etchant, and etching the exposed location a second time with a basic reagent and remove the layer of polyimide having absorbed etchant, whereby the material surrounding the opening after the second etch is rednered free of absorbed etchant.
Claim 3
Dependent Claim
24 words
The invention as defined in claim 1 wherein the reagent is selected from the group potassium hydroxide, sodium hydroxide, and tetra methyl ammonium hydroxide.
Claim 4
Dependent Claim
13 words
The invention as defined in claim 2 wherein the reagent is potassium hydroxide.
Claim 5
Dependent Claim
17 words
The invention as defined in claim 1 wherein the polyimide is a film on a substrate material.
Claim 6
Dependent Claim
21 words
The invention as defined in claim 4 wherein a plurality of vias are etched in said polyimide to expose the substrate.
Claim 7
Dependent Claim
26 words
The invention as defined in claim 1 wherein the reagent used for the second etch is the same as the reagent used for the first etch.
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) | 1985-10-11 | 1986-04-12 | 1986-10-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-10-11 | 1990-04-12 | 1990-10-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-10-11 | 1994-04-12 | 1994-10-12 | $7700.00 | Window Closed / Lapsed |