US3924093A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pattern delineation method and product so produced
Assignee: AT&T Inc
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Filing: 1973-05-09
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Granted: 1975-12-02
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Expires: 1993-05-09
Abstract
Abstract Supported photomasks useful in the fabrication of printed circuitry are produced by laser machining of amorphous iron oxide film blanks. Resolution improvement relative to that obtained by use of other film materials is ascribed to crystallization of film regions bordering those which are volatilized.
Inventors
- 👤 Martin Feldman
- 👤 Denis Lawrence Rousseau
- 👤 William Robert Sinclair
- 👤 Walter Werner Weick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:07
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/54; G03C; G03C1/00; G03C1/705; H; H10; H10P; H10P76/00; H10P76/20; H10P76/204; H10P76/2041; H10P76/2042; Y; Y10; Y10S; Y10S430/00; Y10S430/146
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
115 words
PROCEDURE FOR THE FABRICATION OF A SUBSTRATE-SUPPORTED PATTERN-DELINEATED FILM, IN WHICH DELINEATION COMPRISES SELECTIVELY REMOVING FILM THEREBY RESULTING IN EXPOSED SUBSTRATE, COMPRISING IRRADIATING PORTIONS OF SAID FILM WITH ELECTROMAGNETIC RADIATION REMOVE FILM WITHIN SAID PORTIONS BY VOLATILIZATION THEREBY BATING UNDERLYING SUBSTRATE, CHARACTERIZED IN THAT SAID FILM COMPRISES OXIDIZED IRON WITH SAID FILM BEING SUFFICIENTLY SOLUBLE SUCH THAT A FILM THICKNESS OF 10,000 ANGSTROM UNITS IS REMOVED BY DISSOLUTION IN AN AQUEOUS SOLUTION OF 6N HC/(6 NORMAL HC/) IN ONE HOUR AT ROOM TEMPERATUREEG.; ABOUT 20*C)-IN WHICH THE SAID ELECTROMAGNETIC RADIATION IS THE COHERENT OUTPUT OF A LASER AND IN WHICH THE LASER OUTPUT IS PULSED WITH PULSE DURATION OF A MAXIMUM OF APPROXIMATELY 1 MICROSECOND.
Claim 2
Dependent Claim
115 words
PROCEDURE FOR THE FABRICATION OF A SUBSTRATE-SUPPORTED PATTERN-DELINEATED FILM, IN WHICH DELINEATION COMPRISES SELECTIVELY REMOVING FILM THEREBY RESULTING IN EXPOSED SUBSTRATE, COMPRISING IRRADIATING PORTIONS OF SAID FILM WITH ELECTROMAGNETIC RADIATION REMOVE FILM WITHIN SAID PORTIONS BY VOLATILIZATION THEREBY BATING UNDERLYING SUBSTRATE, CHARACTERIZED IN THAT SAID FILM COMPRISES OXIDIZED IRON WITH SAID FILM BEING SUFFICIENTLY SOLUBLE SUCH THAT A FILM THICKNESS OF 10,000 ANGSTROM UNITS IS REMOVED BY DISSOLUTION IN AN AQUEOUS SOLUTION OF 6N HC/(6 NORMAL HC/) IN ONE HOUR AT ROOM TEMPERATUREEG.; ABOUT 20*C)-IN WHICH THE SAID ELECTROMAGNETIC RADIATION IS THE COHERENT OUTPUT OF A LASER AND IN WHICH THE LASER OUTPUT IS PULSED WITH PULSE DURATION OF A MAXIMUM OF APPROXIMATELY 1 MICROSECOND.
Claim 3
Dependent Claim
53 words
Procedure of claim 1 in which the interpulse spacing is at least equal to the time constant of the substrate with said time constant being defined as the time interval required to result in a reduction in peak temperature due to irradiation to the fraction 1/e where e is the natural logarithm base.
Claim 4
Dependent Claim
10 words
Procedure of claim 1 in which the laser is Q-switched.
Claim 5
Dependent Claim
13 words
Procedure of claim 3 where the laser contains neodymium as the essential ion.
Claim 6
Dependent Claim
10 words
Procedure of claim 1 where the said laser is cavity-dumped.
Claim 7
Dependent Claim
13 words
Procedure of claim 5 where the laser contains neodymium as the essential ion.
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) | 1978-12-01 | 1979-06-02 | 1979-12-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-01 | 1983-06-02 | 1983-12-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-01 | 1987-06-02 | 1987-12-02 | $7700.00 | Window Closed / Lapsed |