US5439732A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ceramic multi-layer wiring board
Assignee: Denso Corp
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Filing: 1994-01-21
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Granted: 1995-08-08
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Expires: 2014-01-21
Abstract
Abstract In a ceramic multi-layer wiring board, a surface conductor layer is made of a copper-based material and an inner conductor in the ceramic multilayer is a non-copper metal having a melting point higher than a temperature at which the ceramic multilayer is fired, typically Ag. Cu and Ag form eutectic crystals when firing the surface conductor layer of Cu. This can be prevented by connecting the surface conductor layer and the inner conductor with Ag-Pd or a metal which is different from the materials of the surface wiring layer and the inner conductor and which does not form eutectic crystals with the material of the surface wiring layer at the temperature at which the surface wiring layer is fired.
Inventors
- 👤 Takashi Nagasaka
- 👤 Yuji Ontani
- 👤 Mitsuhiro Saitou
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 08:45
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/60; H10W70/62; H10W70/66; H10W70/666; H05; H05K; H05K3/00; H05K3/40; H05K3/4038; H05K3/4053; H05K3/4061; H10W70/01; H10W70/05; H10W70/098; H10W70/611; H10W70/67; H10W70/68; H10W70/685; H05K1/00; H05K1/02; H05K1/03; H05K1/0306; H05K1/09; H05K1/092; H05K2201/00; H05K2201/03; H05K2201/0332; H05K2201/0335; H05K2201/035; H05K2201/0352; H05K2201/09; H05K2201/09209; H05K2201/095; H05K2201/096; H05K3/22; H05K3/24; H05K3/245; H05K3/247; H05K3/248; H05K3/46; H05K3/4611; H05K3/4626; H05K3/4629; H05K3/4644; H05K3/4664; H05K3/4667; H10W90/00; H10W90/701; H10W90/721; H10W90/724; Y; Y10; Y10S; Y10S428/00; Y10S428/901; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/125; Y10T428/12507; Y10T428/12514; Y10T428/12771; Y10T428/12806; Y10T428/12826; Y10T428/1284; Y10T428/12861; Y10T428/12896; Y10T428/24; Y10T428/24802; Y10T428/24917; Y10T428/24926
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
159 words
A ceramic multi-layer wiring board comprising: at least one ceramic layer including at least one inner conductor arranged in or on said at least one ceramic layer, said at least one inner conductor being made of a silver-based material having a melting point higher than a first temperature at which said at least one ceramic layer is fired; a top ceramic layer formed on a first outermost layer of said at least one ceramic layer, said top ceramic layer having a hole; a surface wiring conductor of a copper-based material formed on said top ceramic layer; and a hole-filling conductor filled in said hole in said top ceramic layer and electrically connecting said surface wiring conductor and said at least one inner conductor, said hole-filling conductor [is]being made of a silver alloy which does not form eutectic crystals with said copper-based material of said surface wiring conductor at a second temperature at which said surface wiring conductor is fired.
Claim 2
Dependent Claim
159 words
A ceramic multi-layer wiring board comprising: at least one ceramic layer including at least one inner conductor arranged in or on said at least one ceramic layer, said at least one inner conductor being made of a silver-based material having a melting point higher than a first temperature at which said at least one ceramic layer is fired; a top ceramic layer formed on a first outermost layer of said at least one ceramic layer, said top ceramic layer having a hole; a surface wiring conductor of a copper-based material formed on said top ceramic layer; and a hole-filling conductor filled in said hole in said top ceramic layer and electrically connecting said surface wiring conductor and said at least one inner conductor, said hole-filling conductor [is]being made of a silver alloy which does not form eutectic crystals with said copper-based material of said surface wiring conductor at a second temperature at which said surface wiring conductor is fired.
Claim 3
Dependent Claim
44 words
A ceramic multi-layer wiring board according to claim 1, wherein said copper-based material of said surface wiring conductor is copper, said silver-based material of said at least one inner conductor is silver and said silver alloy of said hole-filling conductor is an Ag-Pd alloy.
Claim 4
Dependent Claim
100 words
A ceramic multi-layer wiring board comprising: at least one ceramic layer including at least one inner conductor of silver arranged in or on said at least one ceramic layer; a top ceramic layer formed on an outermost layer of said at least one ceramic layer, said top ceramic layer having a hole; a surface wiring conductor of copper formed on said top ceramic layer; and a hole-filling conductor filled in said hole in said top ceramic layer and electrically connecting said surface wiring conductor and said at least one inner conductors, said hole-filling conductor being made of a silver-palladium alloy.
Claim 5
Dependent Claim
100 words
A ceramic multi-layer wiring board comprising: at least one ceramic layer including at least one inner conductor of silver arranged in or on said at least one ceramic layer; a top ceramic layer formed on an outermost layer of said at least one ceramic layer, said top ceramic layer having a hole; a surface wiring conductor of copper formed on said top ceramic layer; and a hole-filling conductor filled in said hole in said top ceramic layer and electrically connecting said surface wiring conductor and said at least one inner conductors, said hole-filling conductor being made of a silver-palladium alloy.
Claim 6
Dependent Claim
48 words
A ceramic multi-layer wiring board according to claim 1, wherein said copper-based material of said surface wiring conductor comprises not less than 90% by weight of copper and said silver based material of said at least one inner conductor is one of Ag, Ag-Pt, Ag-Pd, Ag-Pt-Pd and Ag-Au.
Claim 7
Dependent Claim
25 words
A ceramic multi-layer wiring board according to claim 1, wherein said silver alloy of said hole-filling conductor is one of Ag-Pt, Ag-Pd, Ag-Au and Ag-Pt-Pd.
Claim 8
Dependent Claim
94 words
A ceramic multi-layer wiring board according to claim 1, wherein said silver alloy of said hole-filling conductor is an alloy of one of Pd and Pt with a metal composing one of said surface wiring conductor and said at least one inner conductor, a first percent content of said metal in said hole-filling conductor being larger in a first region of said hole-filling conductor adjacent to said at least one inner conductor than a second percent content of said metal in said hole-filling conductor in a second region adjacent to said surface wiring conductor.
Claim 9
Dependent Claim
67 words
A ceramic multi-layer wiring board according to claim 3, wherein a first percent content of Ag in said silver-palladium alloy of said hole-filling conductor is larger in a first region of said hole-filling conductor adjacent to said at least one inner conductor than a second percent content of Ag in said silver-palladium alloy of said hole-filling conductor in a second region adjacent to said surface wiring conductor.
Claim 10
Dependent Claim
29 words
A ceramic multi-layer wiring board according to claim 1, wherein said surface wiring conductor is formed of a copper-based material fired at a temperature of at least 850° C.
Claim 11
Dependent Claim
71 words
A ceramic multi-layer wiring board according to claim 1, further comprising: a bottom ceramic layer formed on a second outermost layer of said at least one ceramic layer, said bottom ceramic layer having holes; said at least one ceramic layer having holes in which said silver-based material is filled; and said holes of said top ceramic layer and said holes of said bottom ceramic layer are filled with said silver alloy.
Claim 12
Dependent Claim
168 words
A ceramic multi-layer wiring board comprising: at least one laminated ceramic layer each having a through hole and each-including at least one inner conductor arranged in said through holes and on said at least one laminated ceramic layer, said at least one inner conductor being made of a silver-based material having a melting point higher than a temperature at which said at least one laminated ceramic layer is fired; top and bottom ceramic layers formed on opposite outermost layers of said at least one ceramic layer, said top and bottom ceramic layers each having through holes in which a silver alloy is filled; and a surface wiring conductor made of a copper-based material formed on at least one of said top ceramic layer and said bottom ceramic layer, said silver alloy electrically connecting said surface wiring conductor to said at least one inner conductor; wherein said silver alloy does not form eutectic crystals with said copper-based material at a temperature at which said surface wiring conductor is fired.
Claim 13
Dependent Claim
168 words
A ceramic multi-layer wiring board comprising: at least one laminated ceramic layer each having a through hole and each-including at least one inner conductor arranged in said through holes and on said at least one laminated ceramic layer, said at least one inner conductor being made of a silver-based material having a melting point higher than a temperature at which said at least one laminated ceramic layer is fired; top and bottom ceramic layers formed on opposite outermost layers of said at least one ceramic layer, said top and bottom ceramic layers each having through holes in which a silver alloy is filled; and a surface wiring conductor made of a copper-based material formed on at least one of said top ceramic layer and said bottom ceramic layer, said silver alloy electrically connecting said surface wiring conductor to said at least one inner conductor; wherein said silver alloy does not form eutectic crystals with said copper-based material at a temperature at which said surface wiring conductor is fired.
Claim 14
Dependent Claim
189 words
A ceramic multi-layer wiring board comprising: at least one laminated ceramic layer including at least one inner conductor arranged in or on said at least one-laminated layer, said at least one inner connector being made of a silver-based material having a melting point higher than a temperature at which said at least one laminated layer is fired; a top ceramic layer formed on an outermost layer of said at least one laminated ceramic layer, said top ceramic layer having a hole; a surface wiring conductor of a copper-based material formed on said top ceramic layer; a hole-filling conductor filled in said hole of said top ceramic layer, said hole-filling conductor comprising: a first region adjacent to said at least one ceramic layer; and a second region adjacent to said surface wiring conductor, said first region and said second region of said hole-filling conductor being made of an alloy of one of Pd and Pt with silver, a first content of a respective one of Pd and Pt in said first region is lower than a second content of said respective one of Pd and Pt in said second region.
Claim 15
Dependent Claim
189 words
A ceramic multi-layer wiring board comprising: at least one laminated ceramic layer including at least one inner conductor arranged in or on said at least one-laminated layer, said at least one inner connector being made of a silver-based material having a melting point higher than a temperature at which said at least one laminated layer is fired; a top ceramic layer formed on an outermost layer of said at least one laminated ceramic layer, said top ceramic layer having a hole; a surface wiring conductor of a copper-based material formed on said top ceramic layer; a hole-filling conductor filled in said hole of said top ceramic layer, said hole-filling conductor comprising: a first region adjacent to said at least one ceramic layer; and a second region adjacent to said surface wiring conductor, said first region and said second region of said hole-filling conductor being made of an alloy of one of Pd and Pt with silver, a first content of a respective one of Pd and Pt in said first region is lower than a second content of said respective one of Pd and Pt in said second region.
Claim 16
Dependent Claim
49 words
A ceramic multi-layer wiring board according to claim 11, wherein: said content of said respective one of Pd and Pt in said first region is not less than 30%; and said content of said respective one of Pd and Pt in said second region is not more than 40%.
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) | 1998-08-07 | 1999-02-06 | 1999-08-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-08-07 | 2003-02-06 | 2003-08-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-08-07 | 2007-02-06 | 2007-08-08 | $7700.00 | Window Closed / Lapsed |