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US4579616A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of fabrication of an optically flat membrane

Assignee: SVG LITHOGRAPHY Inc A CORP OF
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Filing: 1983-11-14
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Granted: 1986-04-01
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Expires: 2003-11-14
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Abstract

Abstract A method for tensioning a thin film on a support ring to achieve an optically flat membrane. The support ring is optically flat with a slight bevel at its outside edge where the membrane is epoxied to the support ring.

Inventors

  • 👤 Henry Windischmann
  • 👤 W. D. Buckley

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-06 18:55
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/22; Y; Y10; Y10S; Y10S430/00; Y10S430/167; Y10S430/168; Y10T; Y10T156/00; Y10T156/10; Y10T156/1052; Y10T156/108; Y10T156/1089; Y10T428/00; Y10T428/24; Y10T428/24942; Y10T428/2495; Y10T428/24959

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 153 words
A method for fabricating an optically flat x-ray mask, comprising the steps of: forming a thin membrane fixed to a transfer ring; forming an annular support ring having an optically flat top and a beveled outer edge extending radially from said optically flat top; applying an epoxy to said beveled outer edge only, leaving said optically flat top devoid of epoxy; placing said thin membrane fixed to said transfer ring on said optically flat top substantially concentric with said optically flat top; applying an annular weight to the outer periphery of said thin membrane around said transfer ring to stretch said thin membrane tautly over said optically flat top and to place said thin membrane adhesively in contact with said epoxy; permitting the epoxy to cure thereby securing said thin membrane to said support ring in an optically flat condition; removing the excess portion of said thin membrane from around said support ring.
Claim 2
Independent Claim 153 words
A method for fabricating an optically flat x-ray mask, comprising the steps of: forming a thin membrane fixed to a transfer ring; forming an annular support ring having an optically flat top and a beveled outer edge extending radially from said optically flat top; applying an epoxy to said beveled outer edge only, leaving said optically flat top devoid of epoxy; placing said thin membrane fixed to said transfer ring on said optically flat top substantially concentric with said optically flat top; applying an annular weight to the outer periphery of said thin membrane around said transfer ring to stretch said thin membrane tautly over said optically flat top and to place said thin membrane adhesively in contact with said epoxy; permitting the epoxy to cure thereby securing said thin membrane to said support ring in an optically flat condition; removing the excess portion of said thin membrane from around said support ring.
Claim 3
Dependent Claim 22 words
A method according to claim 1 wherein, said inner surface is polished to a flatness less than one quarter of a wavelength.
Claim 4
Dependent Claim 24 words
A method according to claim 2 wherein, said membrane is tensioned to a flatness of less than one half a wavelength over its diameter.
Claim 5
Dependent Claim 13 words
A method according to claim 3 wherein, said membrane is made of titanium.
Claim 6
Dependent Claim 13 words
A method according to claim 3 wherein, said membrane is made of SiC.
Claim 7
Dependent Claim 13 words
A method according to claim 3 wherein, said membrane is made of polymide.
Claim 8
Dependent Claim 15 words
A method according to claim 3 wherein, said membrane is made of poly methyl methacrylate.

References Cited (Backward Citations)

US2934317A Cited
US3892973A Cited
US4037111A Cited
US4254174A Cited
US4253029A Cited
US4260670A Cited
US4301237A Cited
US4365257A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1989-03-31 1989-09-30 1990-04-01 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1993-03-31 1993-09-30 1994-04-01 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1997-03-31 1997-09-30 1998-04-01 $7700.00 Window Closed / Lapsed

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