Patent US3640738A successfully refreshed from Google Patents.
US3640738A
Expired / Lapsed
US
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Borosilicate glass composition
Assignee: International Business Machines Corp
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Filing: 1970-11-20
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Granted: 1972-02-08
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Expires: 1990-11-20
Abstract
Abstract A glass composition particularly adapted for use with ceramic materials in electronic module applications having a thermal coefficient of expansion substantially matching the thermal coefficient of expansion of ceramic material, and a low dielectric constant less than 4.5. The composition is a borosilicate glass consisting essentially of SiO2, B2O3, CaO, A12O3, Na2O, K2O, BaO, ZrO2, and MgO in relatively precise amounts.
Inventors
- 👤 John R Detweiler Jr
- 👤 Rao R Tummala
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:42
CPC Classifications
C; C03; C03C; C03C3/00; C03C3/04; C03C3/076; C03C3/089; C03C3/091; C03C3/093
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
19 words
The composition of claim 1 wherein the B2O3 content is in the range of 25- 27 percent by weight.
Claim 2
Dependent Claim
18 words
The composition of claim 1 wherein he B2O3 content is in the range of 28-30 percent by weight.
Claim 3
Dependent Claim
18 words
The composition of claim 1 wherein the B2O3 content is in the range of 30-32 percent by weight.
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) | 1975-02-07 | 1975-08-09 | 1976-02-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-07 | 1979-08-09 | 1980-02-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-07 | 1983-08-09 | 1984-02-08 | $7700.00 | Window Closed / Lapsed |