Patent US4482427A successfully refreshed from Google Patents.
US4482427A
Expired / Lapsed
US
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Process for forming via holes having sloped walls
Assignee: International Business Machines Corp
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Filing: 1984-05-21
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Granted: 1984-11-13
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Expires: 2004-05-21
Abstract
Abstract A dry process for forming via holes with sloped walls by oxygen reactive ion etching through a perforated mask.
Inventors
- 👤 Hiroyuki Hiraoka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 18:38
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/286; H10P50/287; H05; H05K; H05K3/00; H05K3/0011; H05K3/0017
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
89 words
A completely dry process for forming via holes having sloped sidewalls, said process comprising the steps of: (1) covering a substrate with an organic polymer film, (2) positioning a mask above the organic polymer film at a distance of from 20 to 200 microns, and (3) exposing said polymer film to oxygen reactive ion etching through said mask, which has perforations therethrough, but which is otherwise impervious to the oxygen reactive ion etching, until holes are etched through the polymer film in registration with the perforations in the mask.
Claim 2
Dependent Claim
89 words
A completely dry process for forming via holes having sloped sidewalls, said process comprising the steps of: (1) covering a substrate with an organic polymer film, (2) positioning a mask above the organic polymer film at a distance of from 20 to 200 microns, and (3) exposing said polymer film to oxygen reactive ion etching through said mask, which has perforations therethrough, but which is otherwise impervious to the oxygen reactive ion etching, until holes are etched through the polymer film in registration with the perforations in the mask.
Claim 3
Dependent Claim
23 words
A process as claimed in claim 1 wherein the distance between the polymer film and the mask is from 50 to 100 microns.
Claim 4
Dependent Claim
15 words
A process as claimed in claim 1 wherein the organic polymer film is a polyimide.
Claim 5
Dependent Claim
14 words
A process as claimed in claim 1 wherein the mask is made of silicon.
Claim 6
Dependent Claim
19 words
A process as claimed in claim 1 wherein the mask is from about 2 to about 5 microns thick.
Claim 7
Dependent Claim
21 words
A process as claimed in claim 1 wherein the perforations in the mask are from 1 to 15 microns in diameter.
References Cited (Backward Citations)
US4357203A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-11-13 | 1988-05-14 | 1988-11-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-11-13 | 1992-05-14 | 1992-11-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-11-13 | 1996-05-14 | 1996-11-13 | $7700.00 | Window Closed / Lapsed |