An aluminum nitride powder containing a very small amount of coarse particles. An aluminum nitride powder which provides a resin composition having high affinity for resins and high moisture resistance.

The aluminum nitride powder has a volume average particle diameter D50 of 0.5 to 7.0 m in particle size distribution measured with a laser diffraction scattering particle size distribution meter, a D90/D50 ratio of 1.3 to 3.5 and a BET specific surface area of 0.4 to 6.0 m.sup.2/g and classified by removing coarse particles whose particle diameter is more than 5 times as large as D90. When resin paste obtained from this aluminum nitride powder and a resin is measured with a grind gauge, the upper limit particle diameter at which a streak is produced is not more than 5 times as large as D90. Since the classified aluminum nitride powder is surface modified, the aluminum nitride powder which has high filling property in a resin and is excellent in the moisture resistance and insulating property of a resin composition is obtained.

Provided is a method for producing a surface-treated thermally conductive filler, the method including treating the surface of the thermally conductive filler with an alkoxysilane having a specific structure by the chemical vapor deposition method.

An object of the present invention is to provide a surface-modified inorganic nitride having excellent dispersibility. Furthermore, another object of the present invention is to provide a composition, a thermally conductive material, and a device with a thermally conductive layer which contain the surface-modified inorganic nitride. The surface-modified inorganic nitride of the present invention includes an inorganic nitride, and a compound which is represented by General Formula (I) and is adsorbed onto a surface of the inorganic nitride. ##STR00001##

A first object of the present invention is to provide a surface-modified inorganic nitride having excellent dispersibility. Furthermore, a second object of the present invention is to provide a composition, a thermally conductive material, and a device with a thermally conductive layer which contain the surface-modified inorganic nitride. The surface-modified inorganic nitride of the present invention includes an inorganic nitride, and a compound which is represented by General Formula (I) and is adsorbed onto a surface of the inorganic nitride. ##STR00001## In General Formula (1), n represents an integer of 3 or greater. X represents an aromatic hydrocarbon ring group or an aromatic heterocyclic group. Y represents a single bond, O, CO, COO, OCO, S, CS, NR.sup.A, N?N, or a divalent unsaturated hydrocarbon group. R.sup.A represents a hydrogen atom or an alkyl group. R.sup.1 and R.sup.2 each independently represent a substituent. Here, at least one of R.sup.1 or R.sup.2 represents a monovalent organic group containing a specific functional group selected from the group A of specific functional groups. In General Formula (1), a plurality of X's may be the same as or different from each other. Moreover, a plurality of Y's may be the same as or different from each other.

A method for producing an oriented AlN sintered body includes a first step of preparing a formed body by forming a mixture obtained by mixing a sintering aid with an AlN raw-material powder containing a plate-like AlN powder whose plate surface is a c-plane and which has an aspect ratio of 3 or more and an average thickness of 0.05 to 1.8 m, wherein the mixture is formed such that the plate surface of the plate-like AlN powder is disposed along a surface of the formed body; and a second step of obtaining an oriented AlN sintered body by subjecting the formed body to hot-press sintering in a non-oxidizing atmosphere while applying a pressure to the surface of the formed body.

In a first step of a method for producing a transparent AlN sintered body, first, a formed body is prepared by forming a mixture obtained by mixing a sintering aid with an AlN raw-material powder containing a plate-like AlN powder whose plate surface is a c-plane and which has an aspect ratio of 3 or more. At this time, the mixture is formed such that the plate surface of the plate-like AlN powder is disposed along a surface of the formed body. In a second step, an oriented AlN sintered body is obtained by subjecting the formed body to hot-press sintering in a non-oxidizing atmosphere while applying a pressure to the surface of the formed body. In a third step, a transparent AlN sintered body is obtained by sintering the oriented AlN sintered body at normal pressure in a non-oxidizing atmosphere to remove a component derived from the sintering aid.

An inorganic filler included in an epoxy resin composition includes a coating layer formed on a surface thereof, and the surface of the coating layer includes at least two elements selected from the group consisting of C, N and O.

The present invention relates to a composite material for use as a thermal interface material between a heat source and a heat sink. The present invention also relates to the method of synthesizing such a composite material. The composite material has high thermal conductivity, low thermal resistance and functions as an adhesive.

Provided are a novel surface-modified inorganic nitride, a composition, a thermally conductive material, a device with a thermally conductive layer, and a method for manufacturing a surface-modified inorganic nitride. The surface-modified inorganic nitride of the embodiment of the present invention contains an inorganic nitride and an onium salt adsorbed onto a surface of the inorganic nitride.

An aluminum nitride film includes a polycrystalline aluminum nitride. A withstand voltage of the aluminum nitride film is 100 kV/mm or more.