Silicon carbide electrical insulator material of low dielectric constant
AssigneeHitachi, Ltd.
InventorsKunihiro Maeda, Tadahiko Miyoshi
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Abstract
A silicon carbide electrical insulator material of low dielectric constant comprising an electrically insulating sintered body containing silicon carbide as a main constituent and an element providing electrical insulating properties in sintered state, wherein the sintered body comprises an element selected from V family in the periodic table and the carrier concentration within the crystal grain of silicon carbide is 5.times.10.sup.17 cm.sup.-3 or less.
Claims11
A silicon carbide electrical insulator material of low dielectric constant consisting essentially of an electrically insulating sintered body which consists essentially of 0.1 to 3.5 weight % of Be as an element providing electrical insulating properties, 0.005 to 0.5 mol % of at least one element selected from the group consisting of Nb, V, Ta, N, P, As, Sb and Pi, and a balance of silicon carbide, whereby the carrier concentration within the crystal grain of silicon carbide in said sintered body is not more than 5.times.10.sup.17 cm.sup.-3 and said sintered body has electrical resistivity of not less than 10.sup.7 .OMEGA..multidot.cm at room temperature.
A silicon carbide electrical insulating material of low dielectric constant consisting essentially of an electrical insulating sintered body consisting essentially of at least 85 weight % of silicon carbide, 0.1 to 3.5 weight % of beryllium in the form of a compound consisting of beryllium oxide and 0.005 to 0.5 mol % of at least one element selected from the group consisting of Nb, V, Ta, N, P, As, Sb, and Bi;
- said sintered body having a density of at least 95% of the theoretical density of silicon carbide, an electrical resistivity at room temperature of 10.sup.9 .OMEGA..multidot.cm and a heat conductivity at room temperature of at least 0.4 cal/cm.multidot.sec.multidot..degree.C. and the concentration of carrier of acceptor within the crystal grain of silicon carbide is not greater than 5.times.10.sup.17 cm.sup.-3.
Dependencies are inferred from the claim text.