US4246054A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polymer membranes for X-ray masks
Assignee: Applied Biosystems Inc
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Filing: 1979-11-13
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Granted: 1981-01-20
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Expires: 1999-11-13
Abstract
Abstract Polymer membranes are formed by spinning a monomer solution on a smooth surface of a plate and heat curing the solution to form a polymer film. A carrier element is attached to the film and together they are immersed in a suitable chemical composition to react with the bond between the film and plate. The assembly is then immersed in water to cause the plate to fall away from the film.
Inventors
- 👤 James F. Nester
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 19:33
CPC Classifications
B; B29; B29D; B29D7/00; B29D7/01; G; G03; G03F; G03F1/00; G03F1/22
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
90 words
A method of forming a free standing membrane for use in the fabrication of a lithography mask comprising the steps of: a. forming a plastic membrane on a substrate member; b. adhering a ring element to said membrane to provide an assembly; c. immersing edges of said assembly in a chemical solution to loosen a portion of the bonding between said membrane and said substrate member, and d. immersing said assembly in water to cause said substrate member to fall away from said plastic membrane secured to said ring element.
Claim 2
Independent Claim
90 words
A method of forming a free standing membrane for use in the fabrication of a lithography mask comprising the steps of: a. forming a plastic membrane on a substrate member; b. adhering a ring element to said membrane to provide an assembly; c. immersing edges of said assembly in a chemical solution to loosen a portion of the bonding between said membrane and said substrate member, and d. immersing said assembly in water to cause said substrate member to fall away from said plastic membrane secured to said ring element.
Claim 3
Dependent Claim
46 words
A method of forming a membrane as set forth in claim 1 wherein additional steps include providing support means for said assembly in said water and placing said assembly on said support means with said substrate member in the lowermost position free of said support means.
Claim 4
Dependent Claim
35 words
A method of forming a membrane as set forth in claim 2 wherein the step of forming a membrane includes heat curing a monomer solution on said substate member prior to adhering said ring element.
Claim 5
Dependent Claim
55 words
A method of forming a membrane as set forth in claim 3 wherein the step of forming a membrane further includes the step of placing a monomer solution on said substrate member and spinning said substrate member at about 2300 rpm for 120 seconds to spread said monomer solution thereon prior to said heat curing.
Claim 6
Independent Claim
47 words
A method of forming a free standing membrane wherein an additional step includes providing a substrate member having a highly polished surface prior to placing a monomer solution thereon which comprises 4 parts polyamic acid, 1 part N-methyl-2-pyrollidone and 1 part acetone to produce a polyimide membrane.
Claim 7
Independent Claim
47 words
A method of forming a free standing membrane wherein an additional step includes providing a substrate member having a highly polished surface prior to placing a monomer solution thereon which comprises 4 parts polyamic acid, 1 part N-methyl-2-pyrollidone and 1 part acetone to produce a polyimide membrane.
Claim 8
Dependent Claim
26 words
A method as set forth in claim 5 wherein an additional step includes providing a container with hydrofluoric acid therein for the immersion of said assembly.
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) | 1984-01-20 | 1984-07-21 | 1985-01-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-20 | 1988-07-21 | 1989-01-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-20 | 1992-07-21 | 1993-01-20 | $7700.00 | Window Closed / Lapsed |