Kyocera Corporation

Masanobu Ishida

Toshihiro Iwaida

Masahiro Yamamoto

Yoshihiro Okawa

Shinichi Koriyama

Kenji Kitazawa

Kenichiro Miyahara

Hidehiro Minamiue

Takanori Kubo

Koichi Nagata

Shinsuke Takenishi

Nobuyuki Ito

Masamitsu Onitani

Masato Fukudome

Naoyuki Shino

Akira Nakayama

Shigeki Yamada

Fujito Nakakawaji

Noriyoshi Nakanishi

Shigeki Morioka

Norio Okuda

Tomohide Hasegawa

Yasuhiko Yoshihara

Teruhisa Makino

Tsutae Iryou

Hirosi Okayama

Keiko Higashi

Hiroshi Okayama

Hiroaki Sonoda

In a wavelength converter converting a wavelength of light emitted from a light source and outputting an output light containing light whose wavelength is converted, which comprises a fluorescent substance dispersed in a transparent matrix, the fluorescent substance has semiconductor fine particles containing at least one univalent metal element selected from alkali metal and Ag, an element of group III in the periodic table selected from indium and gallium, and sulfur, and does not substantially contain Cd and Se. Hence, a wavelength converter having a conversion efficiency of equal to or more than that of a converter containing CdSe can be provided by using a semiconductor material formed of a highly safe composition.

Wavelength converter, lighting system, and lighting system assembly

A high-frequency module in which a plurality of cavities are formed on the surface of a dielectric board, internal high-frequency signal transmission lines are connected to high-frequency devices in the cavities and are located in the cavities, the internal high-frequency signal transmission lines being electromagnetically coupled to the external high-frequency signal transmission line, and the high-frequency devices in the cavities are connected to each other relying on the electromagnetic coupling through the external line. The high-frequency module enables high-frequency signals to be transmitted among the high-frequency devices with a small loss. The module has a very simple structure, and is cheaply produced, and offers an advantage that it can be easily obtained in a small size.

High-frequency module coupled via aperture in a ground plane

A wiring board having an insulating substrate of aluminum oxide ceramics and a surface wiring layer formed on the surface of said insulating substrate, wherein the aluminum oxide ceramics constituting said insulating substrate contains a manganese compound in an amount of from 2.0 to 10.0% by weight in terms of MnO,, and has a relative density of not smaller than 95%, and said surface wiring layer contains copper in an amount of from 10 to 70% by volume and at least one high-melting metal selected from the group consisting of tungsten and molybdenum in an amount of from 30 to 90% by volume, and further contains copper as a matrix, said copper matrix having a diffusion structure in which are diffused the particles of said high-melting metal having an average particle diameter of from 1 to 10 &mgr;m. The wiring board is prepared by co-firing the conducting paste for forming the surface wiring layer and the green sheet for forming the insulating substrate, and exhibits excellent heat conductivity and electric properties, and is particularly effectively used for the semiconductor devices that execute arithmetic operations at high speeds.

Wire board and method of producing the same

A wiring board of the present invention is equipped with an insulating board formed of a sintered product of silicon nitride containing a silicon nitride crystal phase, and a metal circuit formed on said insulating board, wherein said sintered product of silicon nitride contains a rare earth element (RE) and magnesium in a total amount of from 4 to 30 mol % calculated as oxides and at a molar ratio (RE,O,/MgO) calculated as oxides of from 0.1 to 15, and has a relative density of not smaller than 90% and a heat conductivity of not smaller than 50 W/m&middot;K. The wiring board is equipped with the insulating board having very excellent heat-radiating property and a large strength, and is very useful as a wiring board for, for example, power modules.

Wiring board having excellent heat-radiating property

A sintered aluminum nitride contains rare earth elements (RE) in amounts of from 3 to 10% by weight in terms of RE.sub.2 O.sub.3, alkaline earth elements (R) in amounts of from 0.3 to 3.0% by weight in terms of RO, and silicon atoms in an amount of from 0.3 to 1.0% by weight in terms of SiO.sub.2, the grain boundaries of AlN crystals being chiefly a YAG type crystalline phase. The sintered product is obtained by firing at a temperature as low as 1700.degree. C. or lower, has a thermal conductivity of not smaller than 60 W/m.cndot.K, loses weight in an amount of not more than 10 mg/cm.sup.2 when it is left to stand in a 4N NaOH aqueous solution maintained at 70.degree. C. for one hour, and exhibits excellent resistance against the alkalis.

Sintered aluminum nitride

Disclosed is an aluminum nitride sintered body comprising aluminum nitride and a sintering aid, wherein the sintering aid is composed mainly of at least one component selected, as the oxide, from the group consisting of Yb.sub.2 O.sub.3 and Er.sub.2 O.sub.3, and the sintered body contains up to 0.5% by weight of Yb and/or Er as the metal and has a density of 3.2 to 3.3 g/cm.sup.3 and a heat conductivity of at least 170 W/m.multidot.k. If a CaO component is incorporated as the second sintering aid in an amount of up to 0.1% by weight, the heat conductivity is further increased.

Aluminum nitride sintered body and process for preparation thereof

Disclosed is an aluminium nitride sintered body composed of a sintered body of aluminum nitride, erubium (Er) metal or its compound and calcium (Ca) metal or its compounds, said sintered body containing 1.8 to 10% by weight of an erubium component calculated as an oxide and more than 0 to not more than 2% by weight of a calcium component calculated as an oxide, and consisting of crystal grains of aluminum nitride and an intergranular phase composed mainly of an aluminate other than Er.sub.3 Al.sub.5 O.sub.12, said sintered body further having a bulk density of 3.2 to 3.6 g/cm.sup.3.

Aluminum nitride sintered body

A ceramic heater having a ceramic substrate, a heat-generating resistor disposed in the interior of the ceramic substrate or on the surface of the ceramic substrate and terminals connected to both the ends of the heat-generating resistor, wherein the ceramic substrate is composed of a sintered body of a nitride of an element selected from the group consisting of silicon and aluminum and the heat-generating resistor is composed of a ceramic layer containing titanium nitride (TiN) or tungsten carbide (WC).

Ceramic heater

Growing community of inventors

Kirishima, Japan

Masanobu Ishida