US4939569A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ultraviolet transmitting glasses for EPROM windows
Assignee: Corning Inc
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Filing: 1989-12-11
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Granted: 1990-07-03
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Expires: 2009-12-11
Abstract
Abstract Ultraviolet transmitting glasses exhibiting coefficients of thermal expansion between 46-52×10 -7 /°C. and transmittances at a thickness of 1 mm of at least 80% at a wavelength of 254 nm which are essentially free of fluoride and consist essentially, in mole percent, of 60-70% SiO 2 , 16-20% B 2 O 3 , 1-8% Al 2 O 3 , 1-6% Li 2 O, 2.5-5% N 2 O, 0-3% K 2 O, and 0-1.25% Cl, w9herein the mole ratio R 2 O:R 2 O 3 is greater than 0.3, but less than 0.5.
Inventors
- 👤 Gerald J. Fine
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 23:47
CPC Classifications
C; C03; C03C; C03C3/00; C03C3/04; C03C3/076; C03C3/11; C03C3/089; C03C3/091
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
148 words
An EPROM package comprising: (a) an insulating board having a chip mounting portion and having conductive interconnecting patterns thereon; one end of each of said patterns being adjacent to said chip mounting portion; (b) an EPROM chip mounted on said chip mounting portion; said chip having a plurality of electrodes on a surface thereof; (c) means for connecting said electrodes to one end of each of said patterns; and (d) a covering insulating board containing a window composed of an ultraviolet transmitting glass; in which said ultraviolet transmitting glass has a composition which is free of fluoride and consists essentially, expressed in terms of mole percent on the oxide basis, of ______________________________________
SiO.sub.2
60-70 Na.sub.2 O
2.5-5
B.sub.2 O.sub.3
16-20 K.sub.2 O
0-3
Al.sub.2 O.sub.3
1-8 Li.sub.2 O
1-6
______________________________________ Wherein the mole ratio R 2 O:R 2 O 3 is greater than 0.3, but less than 0.5.
Claim 2
Dependent Claim
148 words
An EPROM package comprising: (a) an insulating board having a chip mounting portion and having conductive interconnecting patterns thereon; one end of each of said patterns being adjacent to said chip mounting portion; (b) an EPROM chip mounted on said chip mounting portion; said chip having a plurality of electrodes on a surface thereof; (c) means for connecting said electrodes to one end of each of said patterns; and (d) a covering insulating board containing a window composed of an ultraviolet transmitting glass; in which said ultraviolet transmitting glass has a composition which is free of fluoride and consists essentially, expressed in terms of mole percent on the oxide basis, of ______________________________________
SiO.sub.2
60-70 Na.sub.2 O
2.5-5
B.sub.2 O.sub.3
16-20 K.sub.2 O
0-3
Al.sub.2 O.sub.3
1-8 Li.sub.2 O
1-6
______________________________________ Wherein the mole ratio R 2 O:R 2 O 3 is greater than 0.3, but less than 0.5.
Claim 3
Dependent Claim
22 words
An EPROM package according to claim 1 wherein the batch for said ultraviolet transmitting glass composition also contains up to 1.25% Cl.
Claim 4
Dependent Claim
43 words
An EPROM package according to claim 2 wherein said ultraviolet transmitting glass has the approximate composition, as calculated from the batch, of ______________________________________
SiO.sub.2 68.1 Na.sub.2 O
4.8
B.sub.2 O.sub.3
18.9 K.sub.2 O
1.5
Al.sub.2 O.sub.3
4.3 Cl 1.1
Li.sub.2 O
1.3
______________________________________
References Cited (Backward Citations)
US4460915A
Cited
US4630172A
Cited
US4710797A
Cited
US4644384A
Cited
US4663833A
Cited
US4723156A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-07-02 | 1994-01-01 | 1994-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-07-02 | 1998-01-01 | 1998-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-07-02 | 2002-01-01 | 2002-07-03 | $7700.00 | Window Closed / Lapsed |