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Patent
Covalent Materials Corporation | Date: 2015-06-23

A heat insulating material includes a porous sintered body formed of MgAl_(2)O_(4 )and having a porosity of 60% or more and less than 73%. In the heat insulating material, pores having a pore diameter of 0.8 m or more and less than 10 m occupy 30 vol % or more and less than 90 vol % of a total pore volume, pores having a pore diameter of 0.01 m or more and less than 0.8 m occupy 10 vol % or more and less than 60 vol % of the total pore volume, the thermal conductivity at 20 C. or higher and 1500 C. or lower is 0.45 W/(mK) or less, and the compressive strength is 2 MPa or more.


Patent
Covalent Materials Corporation | Date: 2015-03-02

Provided is a wavelength converting member made of a sintered body which inhibits color unevenness of exit light after wavelength conversion and has excellent light emitting efficiency and inhibited decrease in mechanical strength. The wavelength converting member includes a plate-like sintered body having one principal surface as a light entrance surface and the other principal surface opposite to the entrance surface as a light exit surface, in which the plate-like sintered body has a porosity of 0.1% or less which has fluorescent material grains containing an activator and light-transmitting material grains, the entrance surface and the exit surface are a sintered surface in which the fluorescent material grains and light-transmitting material grains are exposed without processing.


Patent
Covalent Materials Corporation | Date: 2015-02-25

There is provided a focus ring formed without an adhesive that can suppress abnormal electric discharge and obtain uniform plasma environment in a circumferential direction in a plasma processing apparatus. The focus ring includes a plurality of arc-shaped members and a plurality of connecting members connecting the plurality of the arc-shaped members to form a ring shape without an adhesive, and is formed such that a thickness between an upper surface of the connecting member and a bottom surface of a concave fitting portion of the connecting member is greater than a thickness between an upper surface of the arc-shaped member and a bottom surface of a second depression of the arc-shaped member.


Patent
Covalent Materials Corporation | Date: 2013-08-21

A heat-insulating material is provided in which thermal conductivity is controlled not to increase and good insulation properties are held even in a high temperature range. The heat-insulating material is formed of a spinel porous sintered body having a porosity of 65 to 90 vol. % and represented by a chemical formula XAl_(2)O_(4 )(XZn, Fe, Mg, Ni, or Mn) which is arranged such that large pores having a diameter of greater than 1000 m occupy 25 vol. % or less of the total pore volume, fine pores having a diameter of 0.45 m or less occupy 5 to 40 vol. % of the volume of the pores having a diameter of 1000 m or less, at least one pore-diameter distribution peak is within a range of 0.14 to 10 m, and is formed of sintered particles having a calculated average particle diameter of 0.04 to 1 m.


Patent
Covalent Materials Corporation | Date: 2014-04-22

A nitride semiconductor substrate is provided which is suitable for a high withstand voltage power device and prevents a warp and a crack from generating in a Si substrate when forming a thick nitride semiconductor layer on the substrate. A nitride semiconductor substrate 1 is prepared in such a manner that a buffer layer 3 and a semiconductor active layer 4 each comprising a group 13 nitride are stacked one by one on one principal plane of a Si single crystal substrate, the one principal plane has an offset angle of 0.1 to 1 or 1 to 0.1 with respect to a (111) plane, an average dopant concentration in a bulk is 110^(18 )to 110^(21 )cm^(3), the Si single crystal substrate 2 has a SiO_(2 )film on the back, and the total thickness of the buffer layer 3 and the semiconductor active layer 4 is 4 to 10 m.


Patent
Covalent Materials Corporation | Date: 2014-10-29

A nitride semiconductor substrate is provided which is suitable for a high withstand voltage power device and prevents a warp and a crack from generating in a Si substrate when forming a thick nitride semiconductor layer on the substrate. A nitride semiconductor substrate 1 is prepared in such a manner that a buffer layer 3 and a semiconductor active layer 4 each comprising a group 13 nitride are stacked one by one on one principal plane of a Si single crystal substrate, the one principal plane has an offset angle of 0.1 to 1 or -1 to -0.1 with respect to a (111) plane, an average dopant concentration in a bulk is 110^(18) to 110^(21) cm^(-3), the Si single crystal substrate 2 has a SiO_(2) film on the back, and the total thickness of the buffer layer 3 and the semiconductor active layer 4 is 4 to 10 m.


Patent
Covalent Materials Corporation | Date: 2013-09-04

Acarbon-fiber-reinforcedsilicon-carbide-basedcomposite material which has better strength and toughness, and a braking material, such as a brake disc using the composite material, are provided. By using the carbon-fiber-reinforced silicon-carbide-based composite material including a bundle of fibers having chopped carbon fibers arranged in parallel and the other carbon component, carbon, silicon, and silicon carbide, in which the fiber bundle is flat, its cross-section perpendicular to its longitudinal direction has a larger diameter of 1 mm or more, a ratio of the larger diameter to a smaller diameter is from 1. 5 to 5, and a plurality of the fiber bundles are randomly oriented substantially along a two-dimensional plane, and a two-dimensional side serves as a braking side to thereby constitute the braking material.


Patent
Covalent Materials Corporation | Date: 2015-06-30

One aspect of the heat insulator of the present invention includes a porous sintered body having a porosity of 70 vol % or more and less than 91 vol %, and pores having a pore size of 0.8 m or more and less than 10 m occupy 10 vol % or more and 70 vol % or less of the total pore volume, while pores having a pore size of 0.01 m or more and less than 0.8 m occupy 5 vol % or more and 30 vol % or less of the total pore volume. The porous sintered body is formed from an MgAl_(2)O_(4 )(spinel) raw material and fibers formed of an inorganic material, the heat conductivity of the heat insulator at 1000 C. or more and 1500 C. or less is 0.40 W/(mK) or less, and the weight ratio of Si relative to Mg in the porous sintered body is 0.15 or less.


Patent
Covalent Materials Corporation | Date: 2014-05-07

A nitride semiconductor substrate suitable for a high withstand voltage power device is provided in which current collapse is controlled, while reducing leakage current. In a nitride semiconductor substrate, wherein a buffer layer, an active layer, and an electron supply layer, each comprising a group 13 nitride, are stacked one by one on a silicon single crystal substrate, the buffer layer has a structure where a multilayer stack in which a pair of nitride layers having different concentrations of Al or Ga are repeatedly deposited a plurality of times on an initial layer of Al_(x)Ga_(1-x)N (0x1) is stacked, and includes a doping layer whose carbon concentration is 110^(18 )to 110^(21 )cm^(3 )and whose Si concentration is 110^(17 )to 110^(20 )cm^(3), a thickness of the doping layer is 15% or more of the total thickness of the buffer layer.


Patent
Covalent Materials Corporation | Date: 2013-02-07

The present invention relates to a ceramics composite including: a matrix phase including Al_(2)O_(3 )or a substance in which one selected from Sc_(2)O_(3 )and Ga_(2)O_(3 )is incorporated into Al_(2)O_(3); a main phosphor phase formed in the matrix phase and including a substance represented by a general formula A_(3)B_(5)O_(12):Ce in which A is at least one selected from Y, Gd, Tb, Yb and Lu and B is at least one selected from Al, Ga and Sc; and a CeAl_(11)O_(18 )phase mixed in the matrix phase and the main phosphor phase.

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