Ngk Insulators, Inc.

Nkg Insulators, Ltd.

Hiroharu Kobayashi

Takahiro Tomita

Yoshimasa Kobayashi

Jungo Kondo

Morimichi Watanabe

Iwao Ohwada

Tatsuo Kawaguchi

Akinobu Oribe

Kazuki Iida

Tomoyoshi Tai

Yoshio Kikuchi

Yudai Uno

Tatsuya Hishiki

Hiroyuki Shibata

Yoshio Suzuki

Kenichi Hidaka

Miyuki Kojima

Kenkichi Nagai

Yasutaka Awakura

Shinsaku Maeda

Yuta Matsuno

Hirohisa Ogawa

There is provided an AlN single-crystal substrate of a circular shape with a radius r, wherein when the AlN single-crystal substrate is sectioned into three regions, the three regions being a central section, which is a region radially extending from a center of the AlN single-crystal substrate to 0.4r, a middle section, which is a region excluding the central section from a region radially extending from the center of the AlN single-crystal substrate to 0.7r, and an outer circumferential section, which is a region excluding the central section and the middle section from an entire region of the AlN single-crystal substrate, a dislocation density Dc of the central section, a dislocation density Dm of the middle section, and a dislocation density Dp of the outer circumferential section satisfy the relationship Dm>Dp>Dc.

AlN single crystal substrate

A thermal insulation member is directly or indirectly sandwiched between a first object and a second object and thereby suppresses or interrupts heat transfer between the first object and the second object. The thermal insulation member comprises: a first main surface opposed to the first object; and a second main surface positioned on the opposite side from the first main surface and opposed to the second object. The thermal insulation member has a porous structure of ceramic having pores. ZrOparticles and different type material exist on surfaces of the ZrOparticles form a skeleton of the porous structure. The different type material includes at least one selected out of SiO, TiO, LaO, and YO.

Thermal insulation member

A bonded body for an optical modulator includes a supporting substrate, an optical waveguide material provided on the supporting substrate and composed of lithium niobate, lithium tantalate and lithium niobate-lithium tantalate, and an optical waveguide in the optical waveguide material. The supporting substrate is composed of a material selected from the group consisting of magnesium oxide and a magnesium-silicon composite oxide.

Bonded bodies for optical modulators, optical modulators and a method of producing bonded bodies for optical modulators

An aluminum nitride plate satisfies a 'c1&#x3e;97.5%', a 'c2&#x3e;97.0%', a &#x201c;w1&#x3c;2.5 degrees&#x201d;, and a &#x201c;w1/w2&#x3c;0.995&#x201d; where c1 is a c-plane degree of orientation that is defined as a ratio of a diffraction intensity of (002) plane when a surface layer of the aluminum nitride plate is subjected to an X-ray diffraction measurement, and c2 is a c-plane degree of orientation that is defined as a ratio of the diffraction intensity of (002) plane when a portion other than the surface layer of the aluminum nitride plate is subjected to the X-ray diffraction measurement, wherein w1 is a half-value width in an X-ray rocking curve profile of (102) plane of the surface layer and w2 is a half-value width in the X-ray rocking curve profile of (102) plane of the portion other than the surface layer.

Aluminum nitride plate

Aluminum nitride particles used as a material of an aluminum nitride sintered compact are disclosed. The aluminum nitride particles may have a same crystal orientation. The aluminum nitride particles each have an aspect ratio of 3 or more, a plate-like shape, a planar length of 0.6 &#x3bc;m or more and 20 &#x3bc;m or less, and a thickness length of 0.05 &#x3bc;m or more and 2 &#x3bc;m or less.

Aluminum nitride particles

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 &#x3bc;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.

Oriented ALN sintered body and method for producing the same

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.

Transparent AlN sintered body and method for producing the same

A porous ceramic structure includes one sheet, and a plurality of porous ceramic particles bonded on the sheet. A gap d formed between adjacent ones of the porous ceramic particles is 10&#x2dc;80 &#x3bc;m.

Porous ceramic structure

A porous ceramic structure has a porous ceramic aggregate configured from a plurality of porous ceramic particles, and the ratio of the number of corners at locations where two other porous ceramic particles are facing a corner of a porous ceramic particle with respect to the number of corners of the porous ceramic particles included in the porous ceramic aggregate is 80% or greater.

A porous ceramic structure has a porosity of 20% to 99%, and includes one principal surface and another principal surface opposite to the one principal surface. At least one cut is formed from the one principal surface toward the other principal surface. An aspect ratio of a divided portion divided by the cut is greater than or equal to 3.

A porous ceramic particle has a porosity of 20% to 99%, and one principal surface of the porous ceramic particle is a mirror surface, and an aspect ratio thereof is greater than or equal to 3.

Porous ceramic particles

A porous plate-shaped filler of the present invention is a plate shape having an aspect ratio of 3 or more, a surface shape is one of a round shape, an oval and a round-corner polygonal shape, and its minimum length is from 0.1 to 50 &#x3bc;m. Furthermore, a sectional shape is one of an arch shape, an elliptic shape, and a quadrangular shape in which at least a part of corners is rounded. Consequently, it is possible to obtain the heat insulation film in which the porous plate-shaped fillersare easy to be laminated and the heat insulation effect improves.

Porous plate-shaped filler, method for producing same, and heat insulation film

Provided is a porous plate-shaped filler that can be used as a material for a heat-insulation film having excellent heat insulation performance. In a porous plate-shaped fillerhaving a plate shape, an aspect ratio is 3 or higher, a minimum length is 0.5 to 50 &#x3bc;m, and an overall porosity is 20 to 90%, and the porosity is lower in the circumferential part than in the center part. When this porous plate-shaped fillerof the present invention is contained in a heat-insulation film, the infiltration of a matrix into the filler is reduced, and thus the thermal conductivity can be lowered. Therefore, even a thin heat-insulation film can have a greater heat-insulation effect than before.

Porous plate-shaped filler

The porous plate-shaped filler aggregate includes a plurality of the porous plate-shaped fillers. The porous plate-shaped fillers have a uniform plate shape with an aspect ratio of 3 or more, a minimum length of 0.1 to 50 &#x3bc;m, a porosity of 20 to 99%, and the deviation of the maximum length among a plurality of the porous plate-shaped fillers, which is obtained by the following formula, is 10% or less.Deviation of the maximum length (%)=standard deviation of the maximum length/average value of the maximum length&#xd7;100 (Here, 'maximum length' is the longest length when the porous plate-shaped fillers are held between a pair of parallel planes.)

Porous plate-shaped filler aggregate, producing method therefor, and heat-insulation film containing porous plate-shaped filler aggregate

In a heat-insulation film, porous plate fillers are dispersed in a matrix to bond the porous plate fillers. The porous plate filler includes plates having an aspect ratio of 3 or more, a minimum length of 0.1 to 50 &#x3bc;m and a porosity of 20 to 90%. In the heat-insulation film, a volume ratio between the porous plate fillers and the matrix is from 50:50 to 95:5. In the heat-insulation film in which the porous plate fillers are used, a length of a heat transfer path increases and a thermal conductivity can be decreased, as compared with a case where spherical or cubic fillers are used.

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Kasugai, Japan

Hiroharu Kobayashi