Patent US4894184A successfully refreshed from Google Patents.
US4894184A
Expired / Lapsed
US
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Low-temperature burnt conductive paste and method of manufacturing printed circuit board
Assignee: Furukawa Electric Co Ltd
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Filing: 1987-04-27
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Granted: 1990-01-16
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Expires: 2007-04-27
Abstract
Abstract A low-temperature burnt conductive paste prepared by dispersing, in an organic vehicle, a base material comprising 50 to 95% by weight of a powder of at least one conductive material selected from the group consisting of a copper alloy, a copper oxide and a copper alloy oxide and 5 to 50% by weight of a glass powder having a softening point of 300° to 600° C. and a coefficient of thermal expansion of 6 to 13×10 -6 °C. -1 , and a method of manufacturing a printed circuit board using this paste.
Inventors
- 👤 Shingoro Fukuoka
- 👤 Kouichi Shintomi
- 👤 Ryu Maeda
- 👤 Kaisuke Shiroyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 18:19
CPC Classifications
H; H05; H05K; H05K1/00; H05K1/02; H05K1/09; H05K1/092; H01; H01B; H01B1/00; H01B1/14; H01B1/16
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
141 words
A low-temperature burnt conductive paste comprising an organic vehicle having dispersed therein a composition comprising 50 to 95% by weight of a powder of at least one conductive material selected from the group consisting of a copper alloy, a copper oxide and a copper alloy oxide and 5 to 50% by weight of a glass powder having a softening point of 300° to 600° C. and a coefficient of thermal expansion of 6 to 13×10 -6 ° C. -1 , said copper alloy being selected from the group consisting of Cu-Ag, Cu-Sn and Cu-Ag-Sn, said Ag-containing alloys having a Ag content of from 0.05 to 50% by weight and, said Sn-containing alloys having a Sn content of from 0.01 to 10% by weight, and each of said copper oxide and copper alloy oxide having an oxidation ratio of 0.1 to 100%.
Claim 2
Dependent Claim
141 words
A low-temperature burnt conductive paste comprising an organic vehicle having dispersed therein a composition comprising 50 to 95% by weight of a powder of at least one conductive material selected from the group consisting of a copper alloy, a copper oxide and a copper alloy oxide and 5 to 50% by weight of a glass powder having a softening point of 300° to 600° C. and a coefficient of thermal expansion of 6 to 13×10 -6 ° C. -1 , said copper alloy being selected from the group consisting of Cu-Ag, Cu-Sn and Cu-Ag-Sn, said Ag-containing alloys having a Ag content of from 0.05 to 50% by weight and, said Sn-containing alloys having a Sn content of from 0.01 to 10% by weight, and each of said copper oxide and copper alloy oxide having an oxidation ratio of 0.1 to 100%.
Claim 3
Dependent Claim
21 words
The paste according to claim 1, wherein the average particle size of said conductive material powder is not more than 10μ.
Claim 4
Dependent Claim
25 words
The paste according to claim 1, wherein said conductive material is flattened to have a flattening ratio (a ratio of length/thickness) of at least 1.5.
Claim 5
Dependent Claim
49 words
The paste according to claim 1, wherein said glass powder having the softening point of 300° to 600° C. and the coefficient of thermal expansion of 6 to 13 ×10 -6 ° C. -1 is a lead-silicate glass containing PbO-B 2 O 3 -SiO 2 as a major component.
Claim 6
Dependent Claim
25 words
The paste according to claim 2, wherein said conductive material is flattened to have a flattening ratio (a ratio of length/thickness) of at least 1.5.
Claim 7
Dependent Claim
48 words
The paste according to claim 5, wherein said glass powder having the softening point of 300° to 600° C. and the coefficient of thermal expansion of 6 to 13×10 -6 ° C. -1 is a lead-borosilicate glass containing PbO-B 2 O 3 -SiO 2 as a major component.
Claim 8
Dependent Claim
48 words
The paste according to claim 2, wherein said glass powder having the softening point of 300° to 600° C. and the coefficient of thermal expansion of 6 to 13×10 -6 ° C. -1 is a lead-borosilicate glass containing PbO-B 2 O 3 -SiO 2 as a major component.
Claim 9
Dependent Claim
16 words
The paste according to claim 7, wherein said conductive material is one of said copper alloys.
Claim 10
Dependent Claim
16 words
The paste according to claim 7, wherein said conductive material is one of said copper oxide.
Claim 11
Dependent Claim
17 words
The paste according to claim 7, wherein said conductive material is one of said copper alloy oxide.
Claim 12
Dependent Claim
16 words
The paste according to claim 1, wherein said conductive material is one of said copper alloy.
Claim 13
Dependent Claim
16 words
The paste according to claim 1, wherein said conductive material is one of said copper oxide.
Claim 14
Dependent Claim
17 words
The paste according to claim 1, wherein said conductive material is one of said copper alloy oxide.
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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) | 1993-01-15 | 1993-07-17 | 1994-01-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-01-15 | 1997-07-17 | 1998-01-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-01-15 | 2001-07-17 | 2002-01-16 | $7700.00 | Window Closed / Lapsed |