Patent US4539298A successfully refreshed from Google Patents.
US4539298A
Expired / Lapsed
US
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Highly heat-conductive ceramic material
Assignee: Toshiba Corp
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Filing: 1982-11-23
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Granted: 1985-09-03
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Expires: 2002-11-23
Abstract
Abstract Disclosed is a highly heat-conductive ceramic material which is basically of SiC-AlN system, comprising SiC, AlN and one or more of metal oxide selected from CaO, BaO and SrO, each in a prescribed amount. The SiC may otherwise be one whose particle surface is coated with the AlN.
Inventors
- 👤 Katsutoshi Komeya
- 👤 Akihiko Tsuge
- 👤 Hiroshi Inoue
- 👤 Hiroyasu Ohta
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 16:50
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/60; H10W70/67; H10W70/69; H10W70/692; C; C04; C04B; C04B35/00; C04B35/515; C04B35/56; C04B35/565; C04B35/58; C04B35/581; H10W40/00; H10W40/20; H10W40/25; H10W40/259; H05; H05K; H05K1/00; H05K1/02; H05K1/03; H05K1/0306
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
73 words
A highly heat-conductive ceramic material which consists essentially of (i) an amount of silicon carbide not less than about 20% by weight and up to about 85% by weight, (ii) from about 0.1 to about 5% by weight of at least one metal oxide selected from the group consisting of calcium oxide, barium oxide and strontium oxide, (iii) 0 to about 5% by weight of carbon, and (iv) the balance of aluminum nitride.
Claim 2
Dependent Claim
73 words
A highly heat-conductive ceramic material which consists essentially of (i) an amount of silicon carbide not less than about 20% by weight and up to about 85% by weight, (ii) from about 0.1 to about 5% by weight of at least one metal oxide selected from the group consisting of calcium oxide, barium oxide and strontium oxide, (iii) 0 to about 5% by weight of carbon, and (iv) the balance of aluminum nitride.
Claim 3
Dependent Claim
21 words
The ceramic material according to claim 1, wherein the amount of said metal oxide ranges from 0.5 to 3% by weight.
Claim 4
Dependent Claim
114 words
The ceramic material according to claim 1, which is prepared by a process comprising mixing (i) not less than about 20 to 85% by weight of silicon carbide powder; (ii) 0.1 to 5% by weight of one or more of powder of metal oxide selected from the group consisting of calcium oxide, barium oxide and strontium oxide or powder of a precursor of said oxide, selected from the group consisting of calcium carbonate, calcium nitrate, barium carbonate, barium nitrate, strontium carbonate and strontium nitrate and (iii) the balance of aluminum nitride powder; forming the powdery mixture into a desired shape, which is then sintered within the temperature range of from 1600° to 1820° C.
Claim 5
Dependent Claim
26 words
The ceramic material according to claim 3, wherein the amount of said metal oxide powder or said precursor thereof ranges from 0.5 to 3% by weight.
Claim 6
Dependent Claim
17 words
The ceramic material according to claim 3, wherein the sintering is performed by a hot press method.
Claim 7
Dependent Claim
19 words
The ceramic material according to claim 3, wherein the sintering is performed by a hot isostatic press (HIP) method.
Claim 8
Dependent Claim
16 words
The ceramic material according to claim 3, wherein the sintering is performed under an ambient pressure.
References Cited (Backward Citations)
US3492153A
Cited
US3649310A
Cited
DE2035767A1
Cited
US4105455A
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GB2023185A
Cited
US4332755A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-09-02 | 1989-03-04 | 1989-09-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-09-02 | 1993-03-04 | 1993-09-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-09-02 | 1997-03-04 | 1997-09-03 | $7700.00 | Window Closed / Lapsed |