Patent US5484073A successfully refreshed from Google Patents.
Patent US4499147A successfully refreshed from Google Patents.
US4499147A
Expired / Lapsed
US
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Silicon carbide substrates and a method of producing the same
Assignee: Ibiden Co Ltd
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Filing: 1982-12-21
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Granted: 1985-02-12
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Expires: 2002-12-21
Abstract
Abstract A silicon carbide substrate having excellent electrical insulation properties is disclosed. The silicon carbide substrate is produced by closely adhering to a surface of a silicon carbide plate body a eutectic oxide layer comprising SiO2 produced by partial oxidation of the plate body and at least one oxide selected from Al2O3, P2O5, B2O3, GeO2, As2O3, Sb2O3, Bi2O3, V2O5, ZnO, PbO, Pb3O4, PbO2, CdO, Na2O, K2O, BeO, CaO, MgO, BaO and SrO.
Inventors
- 👤 Ryo Enomoto
- 👤 Hidetoshi Yamauchi
- 👤 Shoji Tanikawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 04:14
CPC Classifications
H; H10; H10W; H10W99/00; H10W70/00; H10W70/60; H10W70/67; H10W70/69; H10W70/692
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
121 words
A silicon carbide substrate having excellent electrical insulation properties, comprising: a silicon carbide sintered plate body; and a eutectic oxide layer closely adhered to a surface of said sintered plate body and comprising at least 30% by weight of SiO 2 produced by oxidation of silicon carbide constituting said sintered plate body and Al 2 O 3 and an oxide of at least one element selected from the group consisting of phosphorus, boron, germanium, arsenic, antimony, bismuth, vanadium, zinc, lead, cadmium, sodium, potassium, lithium, beryllium, calcium, magnesium, barium and strontium, said eutectic oxide layer having a molar ratio of Al 2 O 3 to SiO 2 of 0.024-1.800, the thickness of said eutectic layer being in the range of 0.5-100 μm.
Claim 2
Dependent Claim
121 words
A silicon carbide substrate having excellent electrical insulation properties, comprising: a silicon carbide sintered plate body; and a eutectic oxide layer closely adhered to a surface of said sintered plate body and comprising at least 30% by weight of SiO 2 produced by oxidation of silicon carbide constituting said sintered plate body and Al 2 O 3 and an oxide of at least one element selected from the group consisting of phosphorus, boron, germanium, arsenic, antimony, bismuth, vanadium, zinc, lead, cadmium, sodium, potassium, lithium, beryllium, calcium, magnesium, barium and strontium, said eutectic oxide layer having a molar ratio of Al 2 O 3 to SiO 2 of 0.024-1.800, the thickness of said eutectic layer being in the range of 0.5-100 μm.
Claim 3
Dependent Claim
20 words
The silicon carbide substrate of claim 1, wherein said silicon carbide sintered plate body has a thickness of 0.1-30 mm.
Claim 4
Dependent Claim
32 words
The silicon carbide substrate of claim 1, wherein said eutectic oxide layer further contains not more than 60% in total of at least one oxide of alkali metals and alkaline earth metals.
Claim 5
Dependent Claim
14 words
The silicon carbide substrate of claim 1, wherein said eutectic oxide layer is vitreous.
Claim 6
Dependent Claim
18 words
The silicon carbide substrate of claim 1, wherein an outer surface of said eutectic oxide layer is smooth.
Claim 7
Dependent Claim
18 words
The silicon carbide substrate of claim 1, wherein said eutectic oxide layer has a thickness of 1.0-60 μm.
Claim 8
Dependent Claim
32 words
The silicon carbide substrate of claim 1, wherein said eutectic oxide layer further contains not more than 60% in total of at least one oxide of alkali metals and alkaline earth metals.
Claim 9
Dependent Claim
121 words
A silicon carbide substrate having excellent electrical insulation properties, comprising: a silicon carbide sintered plate body; and a eutectic oxide layer closely adhered to a surface of said sintered plate body and comprising at least 30% by weight of SiO 2 produced by oxidation of silicon carbide constituting said sintered plate body and Al 2 O 3 and an oxide of at least one element selected from the group consisting of phosphorus, boron, germanium, arsenic, antimony, bismuth, vanadium, zinc, lead, cadmium, sodium, potassium, lithium, beryllium, calcium, magnesium, barium and strontium, said eutectic oxide layer having a molar ratio of Al 2 O 3 to SiO 2 of 0.5-1.0, the thickness of said eutectic layer being in the range of 0.5-100 μm.
Claim 10
Dependent Claim
121 words
A silicon carbide substrate having excellent electrical insulation properties, comprising: a silicon carbide sintered plate body; and a eutectic oxide layer closely adhered to a surface of said sintered plate body and comprising at least 30% by weight of SiO 2 produced by oxidation of silicon carbide constituting said sintered plate body and Al 2 O 3 and an oxide of at least one element selected from the group consisting of phosphorus, boron, germanium, arsenic, antimony, bismuth, vanadium, zinc, lead, cadmium, sodium, potassium, lithium, beryllium, calcium, magnesium, barium and strontium, said eutectic oxide layer having a molar ratio of Al 2 O 3 to SiO 2 of 0.5-1.0, the thickness of said eutectic layer being in the range of 0.5-100 μm.
Claim 11
Dependent Claim
20 words
The silicon carbide substrate of claim 8, wherein said silicon carbide sintered plate body has a thickness of 0.1-30 mm.
Claim 12
Dependent Claim
18 words
The silicon carbide substrate of claim 8, wherein said eutectic oxide layer has a thickness of 0.5-100.0 μm.
Claim 13
Dependent Claim
18 words
The silicon carbide substrate of claim 8, wherein said eutectic oxide layer has a thickness of 1.0-60.0 μm.
Claim 14
Dependent Claim
14 words
The silicon carbide substrate of claim 8, wherein said eutectic oxide layer is vitreous.
Claim 15
Dependent Claim
18 words
The silicon carbide substrate of claim 8, wherein an outer surface of said eutectic oxide layer is smooth.
Claim 16
Dependent Claim
111 words
A silicon carbide substrate having excellent electrical insulation properties, comprising: a silicon carbide sintered plate body having a thickness of 0.1-30 mm; and a eutectic oxide layer closely adhered to a surface of said sintered plate body, having a thickness of 0.5-100 μm, and comprising at least 30% by weight of SiO 2 produced by oxidation of silicon carbide constituting said sintered plate body and an oxide of at least one element selected from the group consisting of phosphorus, boron, germanium, arsenic, antimony, bismuth, vanadium, zinc, lead, cadmium, sodium, potassium, lithium, beryllium, calcium, magnesium, barium and strontium, said eutectic oxide layer having a molar ratio of alumina to silica of 0.024-1.800.
Claim 17
Dependent Claim
111 words
A silicon carbide substrate having excellent electrical insulation properties, comprising: a silicon carbide sintered plate body having a thickness of 0.1-30 mm; and a eutectic oxide layer closely adhered to a surface of said sintered plate body, having a thickness of 0.5-100 μm, and comprising at least 30% by weight of SiO 2 produced by oxidation of silicon carbide constituting said sintered plate body and an oxide of at least one element selected from the group consisting of phosphorus, boron, germanium, arsenic, antimony, bismuth, vanadium, zinc, lead, cadmium, sodium, potassium, lithium, beryllium, calcium, magnesium, barium and strontium, said eutectic oxide layer having a molar ratio of alumina to silica of 0.024-1.800.
Claim 18
Dependent Claim
14 words
The silicon carbide substrate of claim 14, wherein said eutectic oxide layer is vitreous.
Claim 19
Dependent Claim
18 words
The silicon carbide substrate of claim 14, wherein an outer surface of said eutectic oxide layer is smooth.
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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) | 1988-02-12 | 1988-08-13 | 1989-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-02-12 | 1992-08-13 | 1993-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-02-12 | 1996-08-13 | 1997-02-12 | $7700.00 | Window Closed / Lapsed |