Abstract: A ceramic/copper circuit board of an embodiment includes a ceramic substrate and first and second copper plates bonded to surfaces of the ceramic substrate via bonding layers containing active metal elements. In cross sections of end portions of the first and second copper plates, a ratio (C/D) of an area C in relation to an area D is from 0.2 to 0.6. The area C is a cross section area of a portion protruded toward an outer side direction of the copper plate from a line AB, and the area D is a cross section area of a portion corresponding to a right-angled triangle whose hypotenuse is the line AB. R-shape sections are provided at edges of upper surfaces of the first and second copper plates, and lengths F of the R-shape sections are 100 ?m or less.

Abstract: A ceramic heat sink material for a pressure contact structure includes a resin layer on a ceramic substrate. The resin layer can have a durometer (Shore) hardness (A-type) of 70 or less, and an average value of gaps existing in an interface between the ceramic substrate and the resin layer is 3 ?m or less. The resin layer can be formed by solidifying a thermosetting resin which is fluidized at a temperature of 60° C.

Abstract: A ceramic/copper circuit board of an embodiment includes a ceramic substrate and first and second copper plates bonded to surfaces of the ceramic substrate via bonding layers containing active metal elements. In cross sections of end portions of the first and second copper plates, a ratio (C/D) of an area C in relation to an area D is from 0.2 to 0.6. The area C is a cross section area of a portion protruded toward an outer side direction of the copper plate from a line AB, and the area D is a cross section area of a portion corresponding to a right-angled triangle whose hypotenuse is the line AB. R-shape sections are provided at edges of upper surfaces of the first and second copper plates, and lengths F of the R-shape sections are 100 ?m or less.

Abstract: The present invention provides a ceramic heat sink material for a pressure contact structure configured by providing a resin layer on a ceramic substrate, wherein the resin layer has durometer (Shore) hardness (A-type) of 70 or less, and an average value of gaps existing in an interface between the ceramic substrate and the resin layer is 3 ?m or less. Further, it is preferable that the resin layer is formed by solidifying a thermosetting resin which is fluidized at a temperature of 60° C. Due to above structure, there can be obtained a ceramic heat sink and a semiconductor module using the heat sink having a good close-contacting property with respect to the pressing member.

Abstract: There is provided a polycrystalline aluminum nitride base material having a linear expansion coefficient similar to GaN. The polycrystalline aluminum nitride base material as a substrate material for crystal growth of GaN-base semiconductors has a mean linear expansion coefficient of 4.9×10?6/K to 6.1×10?6/K between 20° C. and 600° C. and 5.5×10?6/K to 6.6×10?6/K between 20° C. and 1100° C.

Abstract: The high thermal conductive aluminum nitride sintered body according to the present invention has: a thermal conductivity of 220 W/m·K or more; and a three point bending strength of 250 MPa or more; wherein a ratio (IAl2Y4O9/IAlN) of X-ray diffraction intensity (IAl2Y4O9) of Al2Y4O9 (201 plane) with respect to X-ray diffraction intensity (IAlN) of aluminum nitride (101 plane) is 0.002 to 0.03. According to the foregoing structure, there can be provided an aluminum nitride sintered body having a high thermal conductivity and excellent heat radiating property.

Abstract: The high thermal conductive aluminum nitride sintered body according to the present invention has: a thermal conductivity of 220 W/m·K or more; and a three point bending strength of 250 MPa or more; wherein a ratio (IAl2Y4O9/IAlN) of X-ray diffraction intensity (IAl2Y4O9) of Al2Y4O9 (201 plane) with respect to X-ray diffraction intensity (IAlN) of aluminum nitride (101 plane) is 0.002 to 0.03. According to the foregoing structure, there can be provided an aluminum nitride sintered body having a high thermal conductivity and excellent heat radiating property.

Abstract: The high thermal conductive aluminum nitride sintered body according to the present invention has: a thermal conductivity of 220 W/m·K or more; and a three point bending strength of 250 MPa or more; wherein a ratio (IAl2Y4O9/IAlN) of X-ray diffraction intensity (IAl2Y4O9) of Al2Y4O9 (201 plane) with respect to X-ray diffraction intensity (IAlN) of aluminum nitride (101 plane) is 0.002 to 0.03. According to the foregoing structure, there can be provided an aluminum nitride sintered body having a high thermal conductivity and excellent heat radiating property.

Abstract: The high thermal conductive aluminum nitride sintered body according to the present invention has: a thermal conductivity of 220 W/m·K or more; and a three point bending strength of 250 MPa or more; wherein a ratio (IAl2Y4O9/IAlN) of X-ray diffraction intensity (IAl2Y4O9) of Al2Y4O9 (201 plane) with respect to X-ray diffraction intensity (IAlN) of aluminum nitride (101 plane) is 0.002 to 0.03. According to the foregoing structure, there can be provided an aluminum nitride sintered body having a high thermal conductivity and excellent heat radiating property.

Abstract: A silicon nitride wear resistant member is composed of a ceramic sintered body containing 55 to 75 mass % of silicon nitride, 12 to 28 mass % of silicon carbide, 3 to 15 mass % of at least one element selected from the group consisting of Mo, W, Ta, and Nb in terms of silicide thereof, and 5 to 15 mass % of grain boundary phase composed of a rare earth element-Si—Al—O—N, the wear resistant member having an electrical resistance of 107 to 104 ?·cm, a porosity of 1% or less, and a three point bending strength of 900 MPa or more. The wear resistant member has a predetermined electric resistance (electro-conductivity) in addition to the high strength and toughness inherent in silicon nitride per se, especially has a high sliding characteristic. Also, a method of manufacturing the wear resistant member is provided.

Abstract: A silicon nitride wear resistant member is composed of a ceramic sintered body containing 55 to 75 mass % of silicon nitride, 12 to 28 mass % of silicon carbide, 3 to 15 mass % of at least one element selected from the group consisting of Mo, W, Ta, and Nb in terms of silicide thereof, and 5 to 15 mass % of grain boundary phase composed of a rare earth element-Si—Al—O—N, the wear resistant member having an electrical resistance of 107 to 104 ?·cm, a porosity of 1% or less, and a three point bending strength of 900 MPa or more. The wear resistant member has a predetermined electric resistance (electro-conductivity) in addition to the high strength and toughness inherent in silicon nitride per se, especially has a high sliding characteristic. Also, a method of manufacturing the wear resistant member is provided.

Abstract: Wear resistant member for electronic equipment comprises a silicon nitride sintered body that contains conductivity enhancing particles, and has electrical resistivity in the range from 1 to 105 &OHgr;·m. In silicon nitride sintered body, agglomeration of conductivity enhancing particles in which distance between conductivity enhancing particles is less than 1 &mgr;m exists by 30% or less by area ratio per unit area. Wear resistant member is used for a bearing ball or the like, being applied in a rotation actuator of electronic equipment such as a magnetic recorder and optical disk drive. Malfunction of electronic equipment due to static electricity may be cancelled due to electrical resistivity that silicon nitride sintered body has.

Abstract: Wear resistant member for electronic equipment comprises a silicon nitride sintered body that contains conductivity enhancing particles, and has electrical resistivity in the range from 1 to 105 &OHgr;·m. In silicon nitride sintered body, agglomeration of conductivity enhancing particles in which distance between conductivity enhancing particles is less than 1 &mgr;m exists by 30% or less by area ratio per unit area. Wear resistant member is used for a bearing ball or the like, being applied in a rotation actuator of electronic equipment such as a magnetic recorder and optical disk drive. Malfunction of electronic equipment due to static electricity may be cancelled due to electrical resistivity that silicon nitride sintered body has.