Kyocera Corporation

Katsuhiko Onitsuka

Kenichi Yoshimura

Katsura Hayashi

Shuichi Fukuoka

Yoshitake Terashi

Nobuyoshi Fujikawa

Shinya Kawai

Makoto Higashibeppu

Yoshihiro Fujioka

Harumi Hayashi

Akihiko Nishimoto

Kousei Kamigaki

Tomohiro Kawamoto

Masakazu Yasui

Tomonori Eguchi

Tetsuya Kimura

Satoshi Hamano

Teruya Fujisaki

Akira Hashimoto

Kazutaka Uchi

Hideo Emura

Kazuyoshi Kodama

Masahiro Tomisako

High-frequency ceramics containing SiO , Al O , MgO, ZnO and B O as constituent components, said ceramics comprising: 30 to 50% by weight of a crystal phase containing ZnO and Al O ; 5 to 15% by weight of a crystal phase containing SiO and MgO; and 40 to 60% by weight of an amorphous phase comprising substantially SiO or SiO and B O ; wherein the content of the SiO crystal phase is suppressed to be not larger than 6% by weight. The ceramics has a dielectric loss at 60 GHz of not larger than 15&times;10 , exhibiting excellent high-frequency characteristics, and is very useful as an insulating substrate for the wiring boards that deal with high-frequency signals.

Ceramics having excellent high-frequency characteristics and method of producing the same

Wiring substrate including an insulating substrate made of glass ceramics and having Young's modulus of 120 GPa or less, and a wiring circuit layer made of a high-purity metal conductor in concentration of 99% by weight or more formed on the surface of the insulating substrate and/or inside thereof. This wiring substrate may be a multi-layer wiring substrate that has a plurality of wiring circuit layers. The wiring circuit layer is preferably made of a metal foil.

Ceramic wiring substrate and method of producing the same

A piezoelectric ceramic composition comprising a perovskite compound which contains, as metal components, Pb, Sr, Zr, Ti, Nb, Cr, Y, Co and at least one element selected from La, Gd, Nd, Sm and Pr, and may further contain Sb or Na, wherein when the composition formula is expressed as,

Piezoelectric ceramic composition

A piezo-electric ceramic composition which is favorably used for such applications as ceramic filter, vibrator applying ultrasonic waves, piezo-electric buzzer, piezo-electric ignition unit, ultrasonic wave motor, piezo-electric fan and piezo-electric sensors such as acceleration sensor, knocking sensor, AE sensor, etc. and is particularly used as a member for constituting a piezo-electric actuator. The piezo-electric ceramic composition is a composite perovskite compound which contains, as metal components, Pb, Zr, Ti, Zn, Sb as well as Sr and Ba, or Pb, Zr, Ti, Zn, Sb and at least either one or Sr or Ba, and Ni and Te, wherein when the composition by the molar ratio of metal elements is expressed by the following general formula (1),

Piezo-electric ceramic composition

A multilayer substrate with inner capacitors comprising a dielectric layer sandwiched between upper and lower insulating layers, a couple of printed electrodes in desired patterns within the thickness of the dielectric layer so as to form each capacitor at the portion of the dielectric layer corresponding to the electrodes, and a couple of leading terminals on one surface of the insulating layer, which communicate with the electrodes, the multilayer substrate being characterized in that the dielectric layer is composed of a ceramic composition mainly comprising MTiO.sub.3 -based ceramics (M represents one or several of Ba, Ca, Mg, La, Sr and Nd) and the insulating layer is composed of a ceramic composition mainly comprising MgO-SiO.sub.2 -CaO-based ceramics, which is defined by an area surrounded by the lines connecting points A, B, C, D, E, F and G as shown in FIG. 1 and listed below, wherein X, Y and Z respectively represent weight percent values of MgO, SiO.sub.2 and CaO at points A, B, C, D, E, F and G.

Multilayer substrate with inner capacitors

Disclosed is a slider for a magnetic head, which is composed of a sintered body of a three-component or four-component composition comprising TiO.sub.2, CaO and ZnO or TiO.sub.2, CaO, ZnO and ZrO.sub.2. This sintered body has a texture in which the ZnTiO.sub.4 phase or a combination of the ZnTiO.sub.4 phase and CaZrTi.sub.2 O.sub.7 phase is dispersed in the CaTiO.sub.3 phase. The sintered body is excellent in the cutting property and the chipping resistance characteristic.

Sintered body for magnetic head and process for producing the same

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Kokubu, Japan

Katsuhiko Onitsuka