Patent US4621064A successfully refreshed from Google Patents.
US4621064A
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Low temperature sealing composition with synthetic zircon
Assignee: Nippon Electric Glass Co Ltd
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Filing: 1985-03-18
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Granted: 1986-11-04
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Expires: 2005-03-18
Abstract
Abstract A sealing composition suitable for sealing alumina packages for integrated circuits at a temperature below about 450 DEG C. for a short time of about 10 minutes. The composition is a mixture of 50-80 wt % vitreous solder glass powder of PbO-B2O3 system having a deformation point of 350 DEG C. or less, 1-35 wt % zinc material powder and 1-35 wt % zircon powder. The zircon powder is of a synthetic zircon artificially prepared to eliminate radioactive impurities such as uranium and/or thorium.
Inventors
- 👤 Ichiro Matsuura
- 👤 Fumio Yamaguchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 00:16
CPC Classifications
H; H10; H10W; H10W76/00; H10W76/60; C; C03; C03C; C03C8/00; C03C8/24; C03C8/245; H10W70/00; H10W70/60; H10W70/67; H10W70/68; H10W70/682; H10W90/00; H10W90/701; H10W90/751; H10W90/756
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
81 words
A low temperature sealing composition which radiates no α-rays, consisting of a powdery mixture of 50 -80 wt% glass powder, said glass being vitreous PbO-B 2 O 3 solder glass containing substantially no radioactive substances and having a deformation point of 350° C. or less, 1-35 wt% inert zinc material powder, said zinc material consisting of ZnO, SiO 2 and Al 2 O 3 , and 1-35 wt% synthetic zircon artificially prepared substantially to exclude radioactive substances present in natural zircon.
Claim 2
Dependent Claim
81 words
A low temperature sealing composition which radiates no α-rays, consisting of a powdery mixture of 50 -80 wt% glass powder, said glass being vitreous PbO-B 2 O 3 solder glass containing substantially no radioactive substances and having a deformation point of 350° C. or less, 1-35 wt% inert zinc material powder, said zinc material consisting of ZnO, SiO 2 and Al 2 O 3 , and 1-35 wt% synthetic zircon artificially prepared substantially to exclude radioactive substances present in natural zircon.
Claim 3
Dependent Claim
40 words
A low temperature sealing composition as claimed in claim 1, wherein said powdery mixture consists of 60-75 wt % of the vitreous solder glass powder, 10-30 wt% of said inert zinc material powder, and 2-20 wt% of said synthetic zircon.
Claim 4
Dependent Claim
36 words
A low temperature sealing composition as claimed in claim 1, wherein said vitreous solder glass powder consists essentially of by weight, 70-90% PbO, 10-15% B 2 O 3 , 0-10% SiO 2 , and 0-5% ZnO.
Claim 5
Dependent Claim
36 words
A low temperature sealing composition as claimed in claim 1, wherein said vitreous solder glass powder consists essentially of, by weight, 83-87% PbO, 10-13% B 2 O 3 , 0.5-1.5% SiO 2 , and 0-3% ZnO.
Claim 6
Dependent Claim
33 words
A low temperature sealing composition as claimed in claim 1, wherein said inert zinc material powder consists of, by weight, 68-75% ZnO, 23-28% SiO 2 , and 0.1-8% Al 2 O 3 .
Claim 7
Dependent Claim
104 words
A low temperature sealing composition as claimed in claim 1, wherein said synthetic zircon is a chemical compound produced by treating zircon sand by alkali fusion to make sodium zirconate, dissolving said sodium zirconate in hydrochloric acid aqueous solution to make zirconium hydrochloric acid solution, subjecting said solution to recrystallization to obtain zirconium oxychloride, treating said zirconium oxychloride with sodium hydroxide to form zirconium hydroxide, baking said zirconium hydroxide to form zirconium oxide, mixing said zirconium oxide with silica sand, and baking said mixture of said zirconium oxide and said silica sand at 1200° C. using a fusing agent to form the synthetic zircon.
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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) | 1989-11-03 | 1990-05-05 | 1990-11-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-11-03 | 1994-05-05 | 1994-11-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-11-03 | 1998-05-05 | 1998-11-04 | $7700.00 | Window Closed / Lapsed |