Patent US2206997A successfully refreshed from Google Patents.
Patent US4817276A successfully refreshed from Google Patents.
US4817276A
Expired / Lapsed
US
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Process for producing ceramic substrates for microelectronic circuits
Assignee: Hitachi Ltd
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Filing: 1986-04-02
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Granted: 1989-04-04
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Expires: 2006-04-02
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-crystalline 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 14:46
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: 6
Claim 1
Independent Claim
99 words
A process for producing ceramic substrates which comprises the steps of; forming green sheets from a composition consisting of 70 to 85% by weight of a mullite ceramic and 30 to 15% by weight of a binder composed of 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; printing circuit patterns with a conductor paste comprising a high-melting metal on the green sheets; and sintering the resulting sheets at a temperature of 1550° to 1700° C. in a reducing atmosphere.
Claim 2
Dependent Claim
99 words
A process for producing ceramic substrates which comprises the steps of; forming green sheets from a composition consisting of 70 to 85% by weight of a mullite ceramic and 30 to 15% by weight of a binder composed of 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; printing circuit patterns with a conductor paste comprising a high-melting metal on the green sheets; and sintering the resulting sheets at a temperature of 1550° to 1700° C. in a reducing atmosphere.
Claim 3
Dependent Claim
18 words
The process for producing ceramic substrates according to claim 1, wherein said high-melting metal is tungsten or molybdenum.
Claim 4
Dependent Claim
124 words
A process for producing ceramic substrates which comprises the steps of; forming green sheets from a composition consisting of 70 to 85% by weight of a mullite ceramic and 30 to 15% by weight of a binder composed of 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; forming holes through the green sheets; printing circuit patterns with a conductor paste comprising a high-melting metal on the green sheets; filling the through holes with said conductor paste; laminating a plurality of the resulting green sheets to form a laminate; and sintering the laminate at a temperature of 1550° to 1770° C. in a reducing atmosphere.
Claim 5
Dependent Claim
124 words
A process for producing ceramic substrates which comprises the steps of; forming green sheets from a composition consisting of 70 to 85% by weight of a mullite ceramic and 30 to 15% by weight of a binder composed of 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; forming holes through the green sheets; printing circuit patterns with a conductor paste comprising a high-melting metal on the green sheets; filling the through holes with said conductor paste; laminating a plurality of the resulting green sheets to form a laminate; and sintering the laminate at a temperature of 1550° to 1770° C. in a reducing atmosphere.
Claim 6
Dependent Claim
18 words
The process for producing ceramic substrates according to claim 3, wherein said high-melting metal is tungsten or molybdenum.
References Cited (Backward Citations)
US4109377A
Cited
EP0027825A1
Cited
US4460916A
Cited
US4620264A
Cited
US4528275A
Cited
EP0164028A2
Cited
US4734233A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-04-03 | 1992-10-03 | 1993-04-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-04-03 | 1996-10-03 | 1997-04-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-04-03 | 2000-10-03 | 2001-04-04 | $7700.00 | Window Closed / Lapsed |