US4679320A
Expired / Lapsed
US
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Process for producing multilayer ceramic circuit board with copper
Assignee: Fujitsu Ltd
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Filing: 1985-11-26
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Granted: 1987-07-14
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Expires: 2005-11-26
Abstract
Abstract A process for producing a multilayer ceramic circuit board with copper including the steps of: forming green sheets by doctoring a slurry which includes 100 parts by weight of glass ceramic particles, 5 to 20 parts by weight of a thermally depolymerizable resin binder, 2 to 10 parts by weight of a plasticizer, and up to 2 parts by weight of a fatty acid ethylene oxide adduct type, deflorculant. The glass ceramic includes 20 to 70% by weight of alumina, and 30 to 80% by weight of SiO 2 -B 2 O 3 glass. The process further includes the steps of forming via holes through the green sheets, screen-printing a copper paste on the green sheets, and laminating the green sheets, thereby forming a multilayer structure and firing the multilayer structure in a non-oxidizable atmosphere.
Inventors
- 👤 Yoshihiko Imanaka
- 👤 Hiromi Ogawa
- 👤 Mineharu Tsukada
- 👤 Etsuro Udagawa
- 👤 Kazuaki Kurihara
- 👤 Hiromitsu Yokoyama
- 👤 Nobuo Kamehara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 23:02
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/01; H10W70/05; H10W70/098; H05; H05K; H05K1/00; H05K1/02; H05K1/03; H05K1/0306; H05K1/09; H05K1/092; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49124; Y10T29/4913; Y10T29/49144; Y10T29/49155; Y10T29/49158
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
128 words
A process for producing a multilayer ceramic circuit board with copper comprising the steps of: forming green sheets by doctoring a slurry which comprises 100 parts by weight of glass ceramic particles, 5 to 20 parts by weight of a thermally depolymerizable resin binder, 2 to 10 parts by weight of a plasticizer, and up to 2 parts by weight of a fatty acid ethylene oxide adduct type deflocculant, said glass ceramic comprising 20 to 70% by weight of alumina; and 30 to 80% by weight of SiO 2 -B 2 O 3 type glass; forming via holes through said green sheets; screen-printing a copper paste on said green sheets; laminating said green sheets, thereby forming a multilayer structure; and firing said multilayer structure in a non-oxidizable atmosphere.
Claim 2
Dependent Claim
128 words
A process for producing a multilayer ceramic circuit board with copper comprising the steps of: forming green sheets by doctoring a slurry which comprises 100 parts by weight of glass ceramic particles, 5 to 20 parts by weight of a thermally depolymerizable resin binder, 2 to 10 parts by weight of a plasticizer, and up to 2 parts by weight of a fatty acid ethylene oxide adduct type deflocculant, said glass ceramic comprising 20 to 70% by weight of alumina; and 30 to 80% by weight of SiO 2 -B 2 O 3 type glass; forming via holes through said green sheets; screen-printing a copper paste on said green sheets; laminating said green sheets, thereby forming a multilayer structure; and firing said multilayer structure in a non-oxidizable atmosphere.
Claim 3
Dependent Claim
31 words
A process according to claim 1, wherein said defluocculant is a fatty acid ethylene oxide adduct, preferably, an unsaturated fatty acid ethylene oxide adduct, most preferably, oleic acid ethylene oxide adduct.
Claim 4
Dependent Claim
26 words
A process according to claim 1, wherein said thermally depolymerizable resin is a polymethacrylate resin, a polytetrafluoroethylene resin, a poly-α-methyl styrene resin or a mixture thereof.
Claim 5
Dependent Claim
56 words
A process according to claim 1, wherein said SiO 2 -B 2 O 3 type glass consists of a first component having a softening point higher than the melting point of copper, and as a second component at least one of noncrystallizable and crystallizable glasses having a softening point lower than the melting point of copper.
Claim 6
Dependent Claim
14 words
A process according to claim 3, wherein said noncrystallizable glass is borosilicate or aluminoborosilicate.
Claim 7
Dependent Claim
14 words
A process according to claim 3, wherein said crystallizable glass is cordierite or spodumene.
Claim 8
Dependent Claim
107 words
A process according to claim 1, wherein said firing comprises the steps of: prefiring said multilayer structure in an inert atmosphere containing water vapor, the partial pressure of which is 0.005 to 0.3 atmosphere, first at a temperature of 350° C. to 450° C. where said binder resin thermally depolymerizes, then at a temperature of 650° C. to 900° C. where residual organic substance which was not burnt out in the first step reacts with water vapor to be eliminated; and firing said multilayer structure in an inert atmosphere without water vapor at a temperature higher than 950° C. and lower than the melting point of copper.
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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) | 1990-07-13 | 1991-01-12 | 1991-07-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-07-13 | 1995-01-12 | 1995-07-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-07-13 | 1999-01-12 | 1999-07-14 | $7700.00 | Window Closed / Lapsed |