Silicon nitride sintered body and method of producing the same
AssigneeNGK Insulators, Ltd.
InventorsKiyoshi Araki, Katsuhiro Inoue
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Abstract
A method of producing the silicon nitride sintered body includes the steps of forming a compact of molding materials including silicon nitride powder, a Mg component and a sintering aid, and sintering the molding materials at 1,800 to 2,000° C. under a nitrogen atmosphere. The materials at least include an oxide of Mg in a range of 0.3 to 10 wt. %. A constant temperature is kept for at least 0.5 hours in a temperature range of 1,400 to 1,700° C. before the temperature is increased to the sintering temperature. A silicon nitride body having high thermal conductivity and excellent electrical insulation properties at high temperature can thus be provided.
Claims7
A silicon nitride sintered body, comprising silicon nitride crystalline grains and a grain boundary phase, and containing Mg in an amount of 0.3 to 10 wt. % in terms of an oxide;
- wherein said sintered body has a thermal conductivity of 60 W/mK or more and an electrical resistivity of 1E+13 Ωcm or higher at 125° C.
A circuit substrate, comprising a silicon nitride sintered body comprising silicon nitride crystalline grains and a grain boundary phase, and containing Mg in an amount of 0.3 to 10 wt. % in terms of an oxide;
- wherein said sintered body has a thermal conductivity of 60 W/mK or more and an electrical resistivity of 1E+13 Ωcm or higher at 125° C.
A method of producing a silicon nitride sintered body comprising the steps of:
- forming a compact of a molding material comprising silicon nitride powder, a Mg compound and a sintering aid, said Mg compound being present in an amount 0.3 to 10 wt. % in terms of an oxide;
- holding said compact at a substantially constant holding temperature in a range of 1400° C. to 1700° C. for at least 0.5 hours;
- and
- increasing said holding temperature to a sintering temperature in a range of 1900° C. to 2000° C., and sintering said compact under a nitrogen atmosphere.
Dependencies are inferred from the claim text.