Patent US5338710A successfully refreshed from Google Patents.
US5338710A
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US
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Ceramic substrate sintered at low temperatures
Assignee: Sumitomo Metal Mining Co Ltd
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Filing: 1993-10-13
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Granted: 1994-08-16
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Expires: 2013-10-13
Abstract
Abstract A ceramic substrate sintered at low temperature comprising: 20 to 50% by volume of an anorthite (CaAl 2 Si 2 O 8 ) crystal phase, 1 to 20% by volume of a gahnite (ZnAl 2 O 4 ) crystal phase and the balance of a glass phase and, further, containing 35 to 50% by weight of alumina (Al 2 O 3 ) as a filler. Since the substrate can be sintered at a temperature lower than 900° C., has a mechanical strength as large as more than 2500 kgf/cm 2 and a thermal expansion coefficient of less than 60×10 -7 /°C., Au Ag and Cu can be used as a conductor and the substrate can be used like that existent alumina substrate.
Inventors
- 👤 Juji Ishigame
- 👤 Yoshiaki Matsumura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 16:58
CPC Classifications
C; C03; C03C; C03C14/00; C03C14/004; C03C10/00; C03C10/0054; C03C2214/00; C03C2214/20
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
63 words
A ceramic substrate which is sintered at a temperature below 900° C. and which comprises: 50 to 65% by weight of a mixture composed of 20 to 50% by volume of an anorthite crystal phase, 1 to 20% by volume of a gahnite crystal phase, and a balance of a glass phase; and 35 to 50% by weight of alumina as a filler.
Claim 2
Dependent Claim
63 words
A ceramic substrate which is sintered at a temperature below 900° C. and which comprises: 50 to 65% by weight of a mixture composed of 20 to 50% by volume of an anorthite crystal phase, 1 to 20% by volume of a gahnite crystal phase, and a balance of a glass phase; and 35 to 50% by weight of alumina as a filler.
Claim 3
Dependent Claim
20 words
A ceramic substrate as defined in claim 1, wherein the anorthite crystal phase is from 35 to 50% by volume.
Claim 4
Dependent Claim
20 words
A ceramic substrate as defined in claim 1, wherein the gahnite crystal phase is from 3 to 15% by volume.
Claim 5
Dependent Claim
87 words
A ceramic substrate as defined in claim 1, wherein respective starting oxides, for obtaining the anorthite, gahnite and the glass phase containing a flux comprise 5-20% by weight of CaO, 10-20% by weight of Al 2 O 3 , 30-45% by weight of SiO 2 , 0-10% by weight of MgO, 2.5-20% by weight of ZnO, 10-24% by weight of PbO, 0-5% by weight of B 2 O 3 , 0-2% by weight of Li 2 O and 0.1-1% by weight of Sb 2 O 3 .
Claim 6
Dependent Claim
23 words
A ceramic substrate as defined in claim 1, wherein the grain size of alumina as the filler is from 0.5 to 0.8 μm.
Claim 7
Dependent Claim
160 words
A ceramic substrate sintered at temperature below 900° C. obtained by a method which comprises the steps of: mixing starting oxides comprising 5-20% by weight of CaO, 10-20% by weight of Al 2 O 3 , 30-45% by weight of SiO 2 , 0-10% by weight of MgO, 2.5-20% by weight of ZnO, 10-24% by weight of PbO, 0-5% by weight of B 2 O 3 , 0-2% by weight of Li 2 O and 0.1-1% by weight of Sb 2 O 3 , melting the mixture at 1300° to 1600° C. then gradually cooling the same to form solid glass, finely pulverizing the solid glass to form a glass frit; mixing the resultant glass frit with 35 to 50% by weight of alumina as a filler and with an organic binder, molding the mixture into a layer, laminating several said layers under pressure into a green sheet, and then sintering the sheet at a temperature lower than 900° C.
Claim 8
Dependent Claim
160 words
A ceramic substrate sintered at temperature below 900° C. obtained by a method which comprises the steps of: mixing starting oxides comprising 5-20% by weight of CaO, 10-20% by weight of Al 2 O 3 , 30-45% by weight of SiO 2 , 0-10% by weight of MgO, 2.5-20% by weight of ZnO, 10-24% by weight of PbO, 0-5% by weight of B 2 O 3 , 0-2% by weight of Li 2 O and 0.1-1% by weight of Sb 2 O 3 , melting the mixture at 1300° to 1600° C. then gradually cooling the same to form solid glass, finely pulverizing the solid glass to form a glass frit; mixing the resultant glass frit with 35 to 50% by weight of alumina as a filler and with an organic binder, molding the mixture into a layer, laminating several said layers under pressure into a green sheet, and then sintering the sheet at a temperature lower than 900° C.
Claim 9
Dependent Claim
19 words
A ceramic substrate as defined in claim 6, wherein the sintering step is conducted at 800° to 900° C.
Claim 10
Dependent Claim
29 words
A ceramic substrate as defined in claim 6, including a step of adding one material selected from the group consisting of zircon, cordierite and mullite to the glass frit.
References Cited (Backward Citations)
US4749665A
Cited
US4853349A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1997-08-15 | 1998-02-14 | 1998-08-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-08-15 | 2002-02-14 | 2002-08-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-08-15 | 2006-02-14 | 2006-08-16 | $7700.00 | Window Closed / Lapsed |