Abstract: An ink, and products formed from the ink, formulated at least in part from ceramic particles. The ink is formulated so that it can be used in additive manufacturing processes to form three-dimensional printed bodies. The three-dimensional printed bodies can have graded density and can be infiltrated by an infiltration material.

Abstract: Provided is a piezoelectric thin film device containing: a first electrode layer; and a piezoelectric thin film. The first electrode layer contains a metal Me having a crystal structure. The piezoelectric thin film contains aluminum nitride having a wurtzite structure. The aluminum nitride contains a divalent metal element Md and a tetravalent metal element Mt. [Al] is an amount of Al contained in the aluminum nitride, [Md] is an amount of Md contained in the aluminum nitride, [Mt] is an amount of Mt contained in the aluminum nitride, ([Md]+[Mt])/([Al]+[Md]+[Mt]) is 36 to 70 atom %. LALN is a lattice length of the aluminum nitride in a direction that is approximately parallel to a surface of the first electrode layer with which the piezoelectric thin film is in contact, LMETAL is a lattice length of Me in a direction, and LALN is longer than LMETAL.

Abstract: An aluminum nitride sintered body contains 1 to 5% by weight of yttrium oxide (Y2O3), 10 to 100 ppm by weight of titanium (Ti), and the balance being aluminum nitride (AlN). Accordingly, a volume resistance value and thermal conductivity at a high temperature are improved, and the generation of impurities during a semiconductor manufacturing process can be suppressed.

Abstract: 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 m2/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.

Abstract: An aluminum nitride sintered body for use in a semiconductor manufacturing apparatus is provided. The aluminum nitride sintered body exhibits, in a photoluminescence spectrum thereof in a wavelength range of 350 nm to 700 nm obtained with 250 nm excitation light, a highest emission intensity peak within a wavelength range of 580 nm to 620 nm.

Abstract: 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.

Abstract: 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.

Abstract: A manufacturing method of a mold, the mold having at its surface a plurality of recessed portions whose two-dimensional size is not less than 10 nm and less than 500 nm when viewed in a direction normal to the surface, the method including: (a) providing a mold base, (b) partially anodizing an aluminum alloy layer, thereby forming a porous alumina layer which has a plurality of minute recessed portions; and (c) after step (b), bringing the porous alumina layer into contact with a first etching solution, thereby enlarging the plurality of minute recessed portions of the porous alumina layer. Step (a) of providing the mold base includes (a1) providing a metal base, (a2) forming an aluminum alloy layer on the metal base, and (a3) forming a surface protection layer on the aluminum alloy layer. Step (a2) and step (a3) are performed in a same chamber.

Abstract: A device for switchably influencing electromagnetic radiation includes a phase change material and an optically responsive structure. The phase change material is switchable between at least a first state and a second state. The first state and the second state have different electrical and/or magnetic properties. The optically responsive structure is in contact with the phase change material and has at least a first nanostructure and a second nanostructure. The first nanostructure is being different from the second nanostructure. The first nanostructure is optically responsive at a predetermined electromagnetic wavelength when the phase change material is in its first state, and non-responsive at the predetermined wavelength when the phase change material is in its second state.

Abstract: An electrostatic chuck 1A includes a susceptor 11A having an adsorption face 11a of adsorbing a semiconductor, and an electrostatic chuck electrode 4 embedded in the susceptor. The susceptor 11A includes a plate shaped main body 3 and a surface corrosion resistant layer 2 including the adsorption face 2. The surface corrosion resistant layer 2 is made of a ceramic material comprising magnesium, aluminum, oxygen and nitrogen as main components. The ceramic material comprises a main phase comprising magnesium-aluminum oxynitride phase exhibiting an XRD peak at least in 2?=47 to 50° by CuK? X-ray.

Abstract: According to one embodiment, a semiconductor light emitting device includes first and second conductive layers, a first semiconductor layer of a first conductivity type, a second semiconductor layer of a second conductivity type, and a light emitting part. The second semiconductor layer is provided between the first conductive layer and the first semiconductor layer. The light emitting part is provided between the first and second semiconductor layers. The second conductive layer is in contact with the second semiconductor layer and the first conductive layer between the second semiconductor layer and the first conductive layer. The first and second conductive layers are transmittable to light emitted from the light emitting part. The first conductive layer includes a polycrystal having a first average grain diameter. The second conductive layer includes a polycrystal having a second average grain diameter of 150 nanometers or less and smaller than the first average grain diameter.

Abstract: Disclosed is an aluminum nitride substrate for a circuit board, the substrate having aluminum nitride crystal grains with an average grain size of 2 to 5 ?m and a thermal conductivity of at least 170 W/m·K. The aluminum nitride substrate does not include a dendritic grain boundary phase and has a breakdown voltage of at least 30 kV/mm at 400° C. Also provided is a method for producing the aluminum nitride substrate, including the steps of heating a raw material containing an aluminum nitride powder to 1500° C. at a pressure of at most 150 Pa, then increasing and holding the temperature at 1700 to 1900° C. in a pressurized atmosphere of at least 0.4 MPa using a non-oxidizing gas, then cooling to 1600° C. at a cooling rate of at most 10° C./min.

Abstract: The present invention provides an aluminum nitride substrate and an aluminum nitride circuit board having excellent insulation characteristics and heat dissipation properties and having high strength, a semiconductor apparatus, and a method for manufacturing an aluminum nitride substrate.

Abstract: Disclosed is a method of producing a plate brick, which comprises: adding an organic binder to a refractory raw material mixture containing aluminum and/or an aluminum alloy; kneading them; forming the kneaded mixture into a shaped body; and burning the shaped body in a nitrogen gas atmosphere at a temperature of 1000 to 1400° C., wherein: when a temperature of a furnace atmosphere is 300° C. or more, the atmosphere is set to a nitrogen gas atmosphere; and when the temperature of the furnace atmosphere is 1000° C. or more, an oxygen gas concentration in the atmosphere is maintained at 100 volume ppm or less, and a sum of a carbon monoxide gas concentration and a carbon dioxide gas concentration is maintained at 1.0 volume % or less.

Abstract: Provided is an aluminum nitride sintered body with high optical transmissivity and which has a smooth surface in the unpolished condition after firing. The aluminum nitride sintered body has an oxygen concentration of 450 ppm or less, a concentration of impurity elements excluding oxygen, nitrogen, and aluminum of 350 ppm or less, and an average crystal grain diameter of between 2 ?m and 20 ?m, and also has an arithmetic mean surface height Ra of 1 ?m or less and a maximum height Rz of 10 ?m or less in the unpolished condition after firing.

Abstract: The present invention generally relates to a doped aluminum nitride hardmask and a method of making a doped aluminum nitride hardmask. By adding a small amount of dopant, such as oxygen, when forming the aluminum nitride hardmask, the wet etch rate of the hardmask can be significantly reduced. Additionally, due to the presence of the dopant, the grain size of the hardmask is reduced compared to a non-doped aluminum nitride hardmask. The reduced grain size leads to smoother features in the hardmask which leads to more precise etching of the underlying layer when utilizing the hardmask.

Abstract: A ceramic material according to the present invention mainly contains magnesium, aluminum, oxygen, and nitrogen, the ceramic material has the crystal phase of a MgO—AlN solid solution in which aluminum nitride is dissolved in magnesium oxide, the crystal phase serving as a main phase. Preferably, XRD peaks corresponding to the (200) and (220) planes of the MgO—AlN solid solution measured with CuK? radiation appear at 2?=42.9 to 44.8° and 62.3 to 65.2°, respectively, the XRD peaks being located between peaks of cubic magnesium oxide and peaks of cubic aluminum nitride. More preferably, the XRD peak corresponding to the (111) plane appears at 2?=36.9 to 39°, the XRD peak being located between a peak of cubic magnesium oxide and a peak of cubic aluminum nitride.

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: Disclosed is a method for making an aluminum nitride substrate. At first, aluminum nitride is mixed with a carbonized material. The mixture is made into mixture powder in a granulation process. The mixture powder is sintered at an appropriate temperature so that the carbonized material reacts with oxygen to produce a gaseous carbon compound. The gaseous carbon compound is released, and hence an aluminum nitride substrate is made. Before the making of the aluminum nitride substrate is made, the aluminum nitride powder is mixed with the carbonized material. For the stable heat dispersion of the carbonized material, the heating is even during the sintering. The purity of the aluminum nitride substrate is high, the quality of the aluminum nitride substrate is good, and the size of the aluminum nitride substrate is large. Hence, the yield of the making of the aluminum nitride substrate is high.

Abstract: Flat, thin AlN membranes and methods of their manufacture are made available. An AlN thin film (2) contains between 0.001 wt. % and 10 wt. % additive atomic element of one or more type selected from Group-III atoms, Group-IV atoms and Group-V atoms. Onto a base material (1), the AlN thin film (2) is formable utilizing a plasma generated by setting inside a vacuum chamber a sintered AlN ceramic containing between 0.001 wt. % and 10 wt. % additive atomic element of one or more type selected from Group-III atoms, Group-IV atoms and Group-V atoms, and with the base material having been set within the vacuum chamber, irradiating the sintered AlN ceramic with a laser.

Abstract: Disclosed is a method for removing oxygen from aluminum nitride by carbon. At first, an oven is provided. An aluminum nitride substrate is located in the oven. Nitrogen is introduced into the oven to form an atmosphere of nitrogen. The temperature is increased to the transformation point of the aluminum nitride substrate in the oven. Then, the heating is stopped and quenching is conducted in the oven. Carbon is introduced into the oven in the quenching. Thus, oxygen included in the aluminum nitride substrate reacts with the carbon to produce carbon monoxide or carbon dioxide. The carbon monoxide or carbon is released from the oven as well as the nitrogen. Thus, the aluminum nitride substrate is purified.

Abstract: A ceramic electrostatic chuck according to the present invention includes a dielectric layer with a support layer in contact with the back side of the dielectric layer, and an embedded electrostatic electrode. A wafer is placed on the dielectric layer and the dielectric layer is formed of sintered aluminum nitride containing Sm and has a volume resistivity in the range of 4×109 to 4×1010 ?cm at room temperature. The support layer is formed of sintered aluminum nitride containing Sm and Ce and has a volume resistivity of 1×1013 ?cm or more at room temperature.

Abstract: Embodiments of the invention provide a method and apparatus for protecting a susceptor during a cleaning operation by loading a ceramic cover substrate containing either aluminum nitride or beryllium oxide onto the susceptor before introducing the cleaning agent into the chamber. In one embodiment, an aluminum nitride ceramic cover substrate is provided which includes an aluminum nitride ceramic wafer having a thermal conductivity of greater than 160 W/m-K, a circular-shaped geometry having a diameter within a range from about 11 inches to about 13 inches, a thickness within a range from about 0.030 inches to about 0.060 inches, and a flatness of about 0.010 inches or less. The thermal conductivity may be about 180 W/m-K, about 190 W/m-K, or greater. The thickness may be within a range from about 0.035 inches to about 0.050 inches, and the flatness may be about 0.008 inches, about 0.006 inches, or less.

Abstract: The aluminum-nitride-based composite material according to the present invention is an aluminum-nitride-based composite material that is highly pure with the content ratios of transition metals, alkali metals, and boron, respectively as low as 1000 ppm or lower, has AlN and MgO constitutional phases, and additionally contains at least one selected from the group consisting of a rare earth metal oxide, a rare earth metal-aluminum complex oxide, an alkali earth metal-aluminum complex oxide, a rare earth metal oxyfluoride, calcium oxide, and calcium fluoride, wherein the heat conductivity is in the range of 40 to 150 W/mK, the thermal expansion coefficient is in the range of 7.3 to 8.4 ppm/° C., and the volume resistivity is 1×1014 ?·cm or higher.

Abstract: The aluminum-nitride-based composite material according to the present invention is an aluminum-nitride-based composite material that is highly pure with the content ratios of transition metals, alkali metals, and boron, respectively as low as 1000 ppm or lower, has AlN and MgO constitutional phases, and additionally contains at least one selected from the group consisting of a rare earth metal oxide, a rare earth metal-aluminum complex oxide, an alkali earth metal-aluminum complex oxide, a rare earth metal oxyfluoride, calcium oxide, and calcium fluoride, wherein the heat conductivity is in the range of 40 to 150 W/mK, the thermal expansion coefficient is in the range of 7.3 to 8.4 ppm/° C., and the volume resistivity is 1×1014 ?·cm or higher.

Abstract: A high-purity aluminum nitride sintered body is provided by efficiently removing oxides contained in a raw material powder in producing an aluminum nitride sintered body and preventing composite oxide produced by reaction of oxides contained in the raw material powder with a sintering aid from remaining in the aluminum nitride sintered body. The above sintered body is achieved by an aluminum nitride sintered body having a concentration of residual oxygen excluding attached oxygen of 350 ppm or less.

Abstract: A composition including a polycrystalline metal nitride having a number of grains is provided. These grains have a columnar structure with one or more properties such as, an average grain size, a tilt angle, an impurity content, a porosity, a density, and an atomic fraction of the metal in the metal nitride.

Abstract: A method for producing an aluminum nitride sintered product according to the present invention includes the steps of (a) preparing a powder mixture that contains AlN, 2 to 10 parts by weight of Eu2O3 with respect to 100 parts by weight of AlN, Al2O3 such that a molar ratio of Al2O3 to Eu2O3 is 2 to 10, and TiO2 such that a molar ratio of TiO2 to Al2O3 is 0.05 to 1.2, but not Sm; (b) producing a compact from the powder mixture; and (c) firing the compact by subjecting the compact to hot-press firing in a vacuum or in an inert atmosphere.

Abstract: An insulating material high both in thermal conductivity and light reflectance, and a submount high in heat radiatability for mounting an LED element thereon, capable of raising a light utilization factor and quickly radiating heat generated from the element. For example, used as a substrate material of a submount is a nitride sintered body having a reflectance of light in the wavelength region of from 350 nm to 800 nm of 50% or more and a reflectance of light with a wavelength of 700 nm of 60% or more, obtained by sintering a preform consisting of a composition containing 100 parts by mass of aluminum nitride powder and 0.5 to 10 parts by mass of a compound containing an alkaline earth metal such as 3CaO×Al2O3 in an inert atmosphere containing a specific quantity of carbon vapor, or by burning a coat of a nitride paste applied on a base substrate having a heat resistance at a predetermined temperature.

Abstract: A substrate for a heating assembly comprising a mixture of a mica material with an electrically insulating material, the substrate having a thermal coefficient of expansion that is higher than pure mica. A method of manufacturing the substrate is also disclosed.

Abstract: A coated material for a cutting tool can realize long life-time under severe cutting processing conditions such as high-speed processing, high-feed-rate processing, higher hardness of a material to be cut, cutting of a difficult-to-cut material, etc. In a coated material in which a coating is coated on the surface of a substrate, at least one layer of the coating is a hard film having a cubic metallic compound which includes at least one metal element M selected from Al, Si, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and W, and at least one element selected from C, N and O. An X-ray intensity distribution of an ? axis in a pole figure for a (111) plane of the hard film has a maximum intensity in an ? angle range of 75 to 90°, and an X-ray intensity distribution of an ? axis in a pole figure for a (220) plane of the hard film has a maximum intensity in an ? angle range of 75 to 90°.

Abstract: A high intensity discharge lamp includes an arc tube with a chemical fill, capillaries extended from the arc tube, electrodes fed through the capillaries into the arc tube, and a frit seal that seals the capillaries, where the frit seal includes silica (SiO2) in a range of more than 0 wt % to less than 5 wt %, alumina (Al2O3), and one of dysprosia (Dy2O3) and yttrium oxide (Y2O3). This frit seal material can withstand a higher operating temperature so that the length of the capillaries can be reduced compared to those sealed with conventional frit seal material.

Abstract: Affords an AlxGa1-xN single crystal suitable as an electromagnetic wave transmission body, and an electromagnetic wave transmission body that includes the AlxGa1-xN single crystals. The AlxGa1-xN (0<x?1) single crystal (2) has a dielectric loss tangent of 5×10?3 or lower with a radio frequency signal of at least either 1 MHz or 1 GHz having been applied to the crystal at an atmospheric temperature of 25° C. An electromagnetic wave transmission body (4) includes the AlxGa1-xN single crystal, which has a major surface (2m), wherein the AlxGa1-xN single crystal (2) has a dielectric loss tangent of 5×10?3 or lower with an RF signal of at least either 1 MHz or 1 GHz having been applied thereto at an atmospheric temperature of 25° C.

Abstract: Means for a thermally conductive and electrically insulating material 1 containing an AlN crystal 150 mainly comprising AlN, and a production method thereof. In production, a molten aluminum layer is formed on an AlN substrate 11 with at least its surface comprising AlN in an atmosphere of a non-oxidizing gas, and the molten aluminum layer is then heated in an atmosphere of N2 gas to form an AlN crystal 150 which mainly comprises an AlN layer 125. The means are also a thermally conductive and electrically insulating material having an AlN crystal and an Al gradient layer, and a production method thereof. In production, a heating step of forming a molten aluminum layer 15 on the AlN layer 125 and heating it in an atmosphere of N2 gas is repeated at least twice or more. At this time, the amount of the N2 gas dissolved in the molten aluminum layer is decreased as the heating step is repeated.

Abstract: Methods of forming aluminum oxynitride (AlON) materials include sintering green bodies comprising aluminum orthophosphate or another sacrificial material therein. Such green bodies may comprise aluminum, oxygen, and nitrogen in addition to the aluminum orthophosphate. For example, the green bodies may include a mixture of aluminum oxide, aluminum nitride, and aluminum orthophosphate or another sacrificial material. Additional methods of forming aluminum oxynitride (AlON) materials include sintering a green body including a sacrificial material therein, using the sacrificial material to form pores in the green body during sintering, and infiltrating the pores formed in the green body with a liquid infiltrant during sintering. Bodies are formed using such methods.

Abstract: The aluminum nitride sintered body includes at least europium, aluminum, and oxygen. It was found that a grain boundary phase having a peak having a X-ray diffraction profile substantially the same as that of an Sr3Al2O6 phase could be three-dimensionally continued in the aluminum nitride sintered body to realize a lower resistance without damaging various properties unique to aluminum nitride.

Abstract: The present invention contemplates the addition of zirconium compounds to well known ceramic ballistic materials to increase resistance to penetration by projectiles. In the preferred embodiments of the present invention, the zirconium compound that is employed consists of ZrO2 and is provided in the range of about 0.1% to about 11%, by weight, of starting material before densification. Preferred ranges of proportion of ZrO2 in the finished ceramic material are in the ranges of about 0.30% to about 0.75%, by weight, or about 8-9%, by weight. The ballistic material using the combination of SiC with low volume of sintering aid and ZrO2 raises the theoretical density of the ceramic material to between 3.225 and 3.40 g/cc, which is slightly higher than the typical 3.22 g/cc theoretical density for hot pressed fully dense SiC.

Abstract: There is described a sealing composition for sealing aluminum nitride and aluminum oxynitride ceramics comprising: a mixture of SiO2, at least one other metal oxide, and a silicon additive comprising at least one of silicon metal or a silicide. The silicon additive acts to suppress the formation of nitrogen bubbles during the sealing of articles comprised of aluminum nitride or aluminum oxynitride ceramics, e.g., as in the case of a ceramic discharge vessel for a high intensity discharge lamp.

Abstract: The present invention relates to a process of producing an aluminum nitride sintered body which satisfies both high thermal conductivity and reduction in the shrinkage factor at the time of sintering. The aluminum nitride sintered body is a sintered body of a powder mixture containing an aluminum nitride powder and a sintering aid, characterized by having a thermal conductivity of at least 190 W/m·K and a shrinkage factor represented by the percentage of {(dimensions of the molded body before sintering)?(dimensions of the sintered body after sintering)}/(dimensions of the molded body before sintering) of at most 15%.

Abstract: A high-purity aluminum nitride sintered body is provided by efficiently removing oxides contained in a raw material powder in producing an aluminum nitride sintered body and preventing composite oxide produced by reaction of oxides contained in the raw material powder with a sintering aid from remaining in the aluminum nitride sintered body. The above sintered body is achieved by an aluminum nitride sintered body having a concentration of residual oxygen excluding attached oxygen of 350 ppm or less.

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: Preparation for producing refractory materials, characterized in that it comprises one or more particulate, refractory components and one or more binders, where—the particulate, refractory component has a mean particle diameter of >0.3 m and—the binder is selected from among—from 0.05 to 50% by weight of a very finely particulate binder having a mean particle diameter of from 10 nm to 0.3 m selected from the group consisting of aluminium oxide, titanium dioxide, zirconium dioxide and/or mixed oxides of the abovementioned oxides, —from 0 to 20% by weight of an inorganic binder, from 0 to 20% by weight of a hydraulically setting binder, —from 0 to 15% by weight of an organic, silicon-free binder—and the preparation additionally contains from 0 to 35% by weight of water, where—the proportion of the particulate, refractory component is equal to 100 and the percentages of the further materials in the preparation are based on the particulate component.

Abstract: A conductive channel formed of an (Sm, Ce)Al11O18 is interconnected in grain boundaries of aluminum nitride (AlN) particles, thereby reducing the temperature dependency of the volume resistivity of an AlN sintered body formed therefrom. At the same time, a solid solution of the AlN particles is formed with at least one of C and Mg, to prevent the conductive channel from moving into the AlN particles, thereby maintaining a high volume resistivity within the AlN particles even at a high temperature.

Abstract: An aluminum nitride ceramic including aluminum nitride grains and grain boundary phases comprises a grain boundary phase-rich layer including more amount of the grain boundary phases in a surface layer of the aluminum nitride ceramic than in an inside of the aluminum nitride ceramic. The grain boundary phases in the grain boundary phase-rich layer include at least one of rare earth element and alkali earth element.

Abstract: An aluminum nitride sintered body is provided, wherein an average crystal grain diameter is 2.0 ?m or less, a crystalline phase detected by an X-ray diffractometer is an AlN phase only or an AlN phase and an AlON phase only, and SiO2 or MgO is present in an amount of more than 0.05 wt % to less than 1 wt %.

Abstract: An aluminum nitride-based ceramic sintered body is provided, which is manufactured by sintering an aluminum nitride powder comprising aluminum nitride as a main component, carbon in an amount of 0.1 wt % or more to 1.0 wt % or less, and containing oxygen in an amount that is not greater than 0.7 wt %, wherein carbon and oxygen are dissolved in grains of the aluminum nitride powder. The a-axis length of the lattice constant of the aluminum nitride is in a range of 3.1120 ? or more to 3.1200 ? or less, and the a c-axis length of the lattice constant is in a range of 4.9810 ? or more to 4.9900 ? or less. The volume resistivity of the aluminum nitride-based ceramic sintered body at 500° C. is 109 ?·cm or more.

Abstract: To provide an aluminum nitride powder and an aluminum nitride sintered body which satisfy both high thermal conductivity of an aluminum nitride sintered body and reduction in the shrinkage factor at the time of sintering. An aluminum nitride powder characterized in that it has local maximum values in size in regions of from 3 to 15 ?m, from 0.5 to 1.5 ?m and 0.3 ?m or less, the proportions of particles in the respective regions are from 40 to 70%, from 25 to 40% and from 0.5 to 20% on the volume basis, and it has an oxygen amount of from 0.5 to 1.5 mass %. An aluminum nitride sintered body which is a sintered body of a powder mixture containing the above aluminum nitride powder and a sintering aid, characterized by having a thermal conductivity of at least 190 W/m·K and a shrinkage factor represented by the percentage of {(dimensions of the molded body before sintering)?(dimensions of the sintered body after sintering)}/(dimensions of the molded body before sintering) of at most 15%.

Abstract: There is disclosed a pre-sintering process for reducing non-uniformities in the density of a sintered material comprising (a) providing a mixture of (i) a first sinterable material containing a contaminant the presence of which during sintering of the first sinterable material results in a higher vapor pressure than would occur during sintering of pure first sinterable material and (ii) a second material having a higher affinity for the contaminant than does the first sinterable material; and (b) heating the mixture at a temperature and for a time sufficient to allow the second material to at least partly mitigate the propensity of the contaminant to raise the vapor pressure during the sintering of the first sinterable material. Other embodiments are also disclosed.

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: Disclosed is a method for preparing a high dense aluminum nitride (AlN) sintered body. The method includes the steps of preparing powders for the AlN sintered body comprising Y2O3 of 0.1 to 15 wt %, TiO2 of 0.01 to 5 wt % and MgO of 0.1 to 10 wt %, and obtaining the AlN sintered body with a volume resistivity of 1×1015 ?cm or more at a normal temperature and a relative density of 99% or more. The sintered body is obtained by sintering the powders and then cooling the sintered powders or sintering the powders and then cooling the sintered powders with annealing the sintered powders during the cooling.