US4775647A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sealing glass composite
Assignee: Olin Corp
•
Filing: 1987-03-17
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Granted: 1988-10-04
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Expires: 2007-03-17
Abstract
Abstract The present direct invention is directed to a sealing glass composite comprising a low melting point sealing glass matrix mixed with a particulate additive to increase the effective coefficient of thermal expansion of the resulting sealing glass composite. The sealing glass matrix is in the lead borate family and the particulate additive is preferably calcium fluoride. The glass composite is particularly useful as a semiconductor package sealant.
Inventors
- 👤 Edward F. Smith, III
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 20:16
CPC Classifications
C; C03; C03C; C03C8/00; C03C8/24; C03C8/245; H; H10; H10W; H10W72/00; H10W72/851; H10W72/874; H10W72/884; H10W90/00; H10W90/701; H10W90/731; H10W90/734; H10W90/751; H10W90/756
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
113 words
A glass composite comprising: a first component consisting essentially of a glass matrix selected from the group consisting of lead borate, lead-zinc borate, lead borosilicate and lead-zinc borosilicate glasses, said glass matrix having a coefficient of thermal expansion in excess of about 80×10 -7 in./in./°C. (from ambient to glass transition temperature); and a second component mixed into said first component to increase the effective coefficient of thermal expansion of the resulting glass composite, said second component consisting of an effective amount up to about 30 wt. % of a particulate additive having limited solubility in said glass matrix, said particulate additive being selected from the group consisting of calcium fluoride and barium fluoride.
Claim 2
Dependent Claim
113 words
A glass composite comprising: a first component consisting essentially of a glass matrix selected from the group consisting of lead borate, lead-zinc borate, lead borosilicate and lead-zinc borosilicate glasses, said glass matrix having a coefficient of thermal expansion in excess of about 80×10 -7 in./in./°C. (from ambient to glass transition temperature); and a second component mixed into said first component to increase the effective coefficient of thermal expansion of the resulting glass composite, said second component consisting of an effective amount up to about 30 wt. % of a particulate additive having limited solubility in said glass matrix, said particulate additive being selected from the group consisting of calcium fluoride and barium fluoride.
Claim 3
Dependent Claim
27 words
The glass composite of claim 1 wherein said particulate additive is present in said glass composite in an amount from about 10 to about 30 wt. %.
Claim 4
Dependent Claim
17 words
The glass composite of claim 2 including said particulate additive being substantially insoluble in said glass matrix.
Claim 5
Dependent Claim
28 words
The glass composite of claim 3 wherein less than about 10 wt. % of the particulate additive mixed in said glass matrix is soluble in said glass matrix.
Claim 6
Dependent Claim
28 words
The glass composite of claim 4 wherein said glass composite has a coefficient of thermal expansion of above about 138×10 -7 in./in./°C. (from ambient to glass transition temperature).
Claim 7
Dependent Claim
57 words
The glass composite of claim 5 wherein said glass matrix consists essentially of by weight about 70 to about 85% PbO, up to about 20% ZnO, between about 5 to about 15% B 2 O 3 , up to about 10% SiO 2 , up to about 3% BaO and up to about 5% SnO 2 .
Claim 8
Dependent Claim
14 words
The glass composite of claim 5 wherein said glass composite is a sealing glass.
Claim 9
Dependent Claim
18 words
The glass composite of claim 1 wherein said particulate is sized from about 10 to about 150 microns.
Claim 10
Dependent Claim
18 words
The glass composite of claim 8 wherein said particulate is sized from about 40 to about 150 microns.
Claim 11
Dependent Claim
16 words
The glass composite of claim 9 wherein said composite has a sealing temperature about 400° C.
Claim 12
Dependent Claim
21 words
The glass composite of claim 10 wherein said glass composite has a sealing temperature from above 400° to about 450° C.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-10-04 | 1992-04-04 | 1992-10-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-10-04 | 1996-04-04 | 1996-10-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-10-04 | 2000-04-04 | 2000-10-04 | $7700.00 | Window Closed / Lapsed |