Patent US5116718A successfully refreshed from Google Patents.
US5116718A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Contact printing process
Assignee: Nokia Bell Labs
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Filing: 1991-06-14
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Granted: 1992-05-26
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Expires: 2011-06-14
Abstract
Abstract Disclosed is a method for increasing the resolution in contact printing operations by ensuring an intimate contact between the mask and photoresist. A flow of air is directed at the underside of the workpiece being printed while the mask is in place to provide pressure for the necessary contact.
Inventors
- 👤 William F. Dalton
- 👤 Henry B. Micks, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:32
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/20; G03F7/2002; G03F7/2014; H; H05; H05K; H05K3/00; H05K3/0073; H05K3/0082
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
99 words
A method of defining a pattern in a photoresist layer formed over a first major surface of a substrate comprising the step of: transporting the substrate to a station by means of a manifold; applying a vacuum through said manifold to said substrate at said station to hold it in place; placing a mask in contact with the photoresist layer; applying a flow of gas through said manifold to a second major surface of the substrate opposite to said first surface; and while applying said gas flow, exposing the photoresist layer to a source of light through said mask.
Claim 2
Independent Claim
99 words
A method of defining a pattern in a photoresist layer formed over a first major surface of a substrate comprising the step of: transporting the substrate to a station by means of a manifold; applying a vacuum through said manifold to said substrate at said station to hold it in place; placing a mask in contact with the photoresist layer; applying a flow of gas through said manifold to a second major surface of the substrate opposite to said first surface; and while applying said gas flow, exposing the photoresist layer to a source of light through said mask.
Claim 3
Dependent Claim
15 words
The method according to claim 1 wherein the substrate comprises a printed circuit board material.
Claim 4
Dependent Claim
19 words
The method according to claim 2 wherein the pattern includes line widths in the range 50.8 to 203.2 microns.
Claim 5
Dependent Claim
17 words
The method according to claim 2 wherein the pattern includes line widths of 50.8 to 101.6 microns.
Claim 6
Dependent Claim
25 words
The method according to claim 1 wherein the pressure applied to the second major surface lies within the range 3.5×10 -3 to 9.5×10 -3 ATMS.
Claim 7
Dependent Claim
14 words
The method according to claim 1 wherein the source of light produces ultraviolet light.
Claim 8
Dependent Claim
11 words
The method according to claim 1 wherein the gas comprises air.
References Cited (Backward Citations)
US4060235A
Cited
US4226526A
Cited
US4262594A
Cited
US4504142A
Cited
US4810621A
Cited
US4903631A
Cited
US4927733A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-05-26 | 1995-11-25 | 1996-05-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-05-26 | 1999-11-25 | 2000-05-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-05-26 | 2003-11-25 | 2004-05-26 | $7700.00 | Window Closed / Lapsed |