Patent US5622769A successfully refreshed from Google Patents.
US5622769A
Expired / Lapsed
US
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Ceramic circuit board having a thermal conductivity substrate
Assignee: Toshiba Corp
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Filing: 1994-02-10
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Granted: 1997-04-22
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Expires: 2014-02-10
Abstract
Abstract According to this invention, there is disclosed a thermal conductivity substrate which includes an aluminum nitride sintered body and a coating layer formed on the body of aluminum phosphate and having a surface roughness of 1 μm or less, and which has excellent humidity resistance and chemical resistance.
Inventors
- 👤 Shoji Kozuka
- 👤 Masaru Hayashi
- 👤 Katsuyoshi Oh-Ishi
- 👤 Takaaki Yasumoto
- 👤 Nobuo Iwase
- 👤 Hiroshi Endo
- 👤 Koji Yamakawa
- 👤 Kaoru Koiwa
- 👤 Kiyoshi Iyogi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 09:46
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/38; H10; H10W; H10W70/00; H10W70/60; H10W70/67; H10W70/69; H10W70/692; H05K1/00; H05K1/02; H05K1/03; H05K1/0306; Y; Y10; Y10S; Y10S428/00; Y10S428/901; Y10T; Y10T428/00; Y10T428/24; Y10T428/24802; Y10T428/24917
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
60 words
A ceramic circuit board comprising: a ceramic substrate including an aluminum nitride sintered body having a surface and a coating layer formed on the surface of said sintered body, said coating layer consisting essentially of aluminum phosphate and having a surface roughness of not more than 1 μm; and a conductive pattern formed on a surface of said coating layer.
Claim 2
Dependent Claim
60 words
A ceramic circuit board comprising: a ceramic substrate including an aluminum nitride sintered body having a surface and a coating layer formed on the surface of said sintered body, said coating layer consisting essentially of aluminum phosphate and having a surface roughness of not more than 1 μm; and a conductive pattern formed on a surface of said coating layer.
Claim 3
Dependent Claim
40 words
The circuit board according to claim 1, wherein said conductive pattern is formed by stacking a plurality of conductive thin films on the surface of said coating layer to form a multilayered conductive film and patterning said multilayered conductive film.
Claim 4
Dependent Claim
57 words
The circuit board according to claim 2, wherein said multilayered conductive film has a first layer consisting of at least one metal selected from the group consisting of Ti, Cr, Mo, and W and a second layer consisting of one metal selected from the group consisting of Ni and Cu, and a third layer consisting of Au.
Claim 5
Dependent Claim
33 words
The circuit board according to claim 1, wherein said conductive pattern is formed by coating paste on the surface of said coating layer to form a coating pattern and sintering said coating pattern.
Claim 6
Dependent Claim
31 words
The circuit board according to claim 1, wherein said conductive pattern is formed by directly bonding a copper plate on the surface of said coating layer and patterning said copper plate.
References Cited (Backward Citations)
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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) | 2000-04-21 | 2000-10-21 | 2001-04-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-04-21 | 2004-10-21 | 2005-04-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-04-21 | 2008-10-21 | 2009-04-22 | $7700.00 | Window Closed / Lapsed |