Patent US4935285A successfully refreshed from Google Patents.
US4935285A
Expired / Lapsed
US
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Ceramic substrates for microelectronic circuits and process for producing same
Assignee: Hitachi Ltd
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Filing: 1988-12-06
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Granted: 1990-06-19
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Expires: 2008-12-06
Abstract
Abstract A ceramic substrate for densely integrated semiconductor arrays which is superior in a coefficient of thermal expansion, dielectric constant, strength of metallized bond, and mechanical strength, comprising a sintered body composed essentially of mullite crystals and a non-crystralline binder composed of SiO 2 , Al 2 O 3 , and MgO, is provided.
Inventors
- 👤 Gyozo Toda
- 👤 Takashi Kuroki
- 👤 Shousaku Ishihara
- 👤 Naoya Kanda
- 👤 Tsuyoshi Fujita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 14:59
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/45; C04B41/50; C04B41/51; C04B41/5133; C04B35/00; C04B35/01; C04B35/16; C04B35/18; C04B41/80; C04B41/81; C04B41/85; C04B41/88; H; H10; H10W; H10W70/00; H10W70/60; H10W70/67; H10W70/69; H10W70/692; H05; H05K; H05K1/00; H05K1/02; H05K1/03; H05K1/0306; H05K3/00; H05K3/46; H05K3/4644; H05K3/4673; H05K3/4676; Y; Y10; Y10S; Y10S428/00; Y10S428/901; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49124; Y10T29/49126; Y10T29/49155; Y10T29/49158; Y10T29/49165; Y10T428/00; Y10T428/24; Y10T428/24273; Y10T428/24322; Y10T428/24331; Y10T428/24802; Y10T428/24917; Y10T428/31504; Y10T428/31678
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
60 words
A ceramic substrate which comprises a sintered body composed substantially of 70 to 85% by weight of mullite crystals and 30 to 15% by weight of a noncrystalline binder; said binder comprising 60 to 95% by weight of SiO 2 , 4 to 30% by weight of Al 2 O 3 , and 1 to 10% by weight of MgO.
Claim 2
Dependent Claim
60 words
A ceramic substrate which comprises a sintered body composed substantially of 70 to 85% by weight of mullite crystals and 30 to 15% by weight of a noncrystalline binder; said binder comprising 60 to 95% by weight of SiO 2 , 4 to 30% by weight of Al 2 O 3 , and 1 to 10% by weight of MgO.
Claim 3
Dependent Claim
17 words
The ceramic substrate according to claim 1, on which a wiring conductor of high-melting metal is provided.
Claim 4
Dependent Claim
22 words
The ceramic substrate according to claim 2 through which holes are formed and filled with the same conductor as said wiring conductor.
Claim 5
Dependent Claim
15 words
The ceramic substrate according to claim 2, wherein said high-melting metal is tungsten or molybdenum.
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) | 1993-06-18 | 1993-12-18 | 1994-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-06-18 | 1997-12-18 | 1998-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-06-18 | 2001-12-18 | 2002-06-19 | $7700.00 | Window Closed / Lapsed |