Murata Manufacturing Co., Ltd.

Murata Mfg. Co., Ltd.

Haruhumi Mandai

Masami Yamaguchi

Kunitaro Nishimura

Teruhisa Tsuru

Yasuyuki Naito

Kazutaka Nakamura

Yoshiaki Kohno

Kunisaburo Tomono

Koji Shiroki

Kenji Asakura

Iwao Fukutani

Fumio Nakayama

Kiyoshi Iwai

Eiji Imamura

Takashi Kumokawa

A surface mounting type antenna system 10 is formed by spirally winding a conductor 14 made of copper or copper alloy, with a power supply member 12 provided at one end of the conductor 14, the other end thereof being a free end 13, on the edge faces of a rectangular parallelepiped as a dielectric substrate 11 by printing, deposition, pasting or plating. The dielectric substrate 11 is prepared by stacking a plurality of layers of ceramics, resin or a combination of ceramics and resin. On the underside 111 of the dielectric substrate 11 lies a power supply terminal 15 to which the power supply member 12 of the conductor 14 is connected. The power supply terminal 15 is simultaneously used as a fixing terminal for securing the surface mounting type antenna system 10 to, for example, a mounting board. Moreover, the conductor 14 squarely intersecting the axis C of the conductor winding is rectangular in transverse cross section having a width of w and a length of l.

Surface mounting type antenna system

A thermistor which includes a ceramic sintered body formed of a plurality of inner electrodes alternating with a corresponding plurality of ceramic layers, outer electrodes being connected to specific ones of the inner electrodes. Each ceramic layer a positive temperature coefficient of resistance. The inner electrode layers are obtained by injecting molten base metal having a low melting point such as lead, tin or lead-tin alloy into gap layers previously defined in the sintered body between the laminated ceramic layers from the outside under pressure and hardening the same.

Thermistor having a positive temperature coefficient of resistance

This disclosure is directed to an improved LC filter which includes a cylindrical ferrite member of a semi-conductor material formed with an inner bore which axially extends through its central portion, and having its grain boundary and/or at least its outer peripheral surface formed into an insulating layer, an electrode provided at least on the outer peripheral surface of the cylindrical ferrite member, and a through-conductor inserted into the inner bore of the cylindrical ferrite member.

Monolithic LC feed-through filter having a ferrite body with a

A ceramic composition for use in production of non-linear resistors. This composition comprises strontium titanate (or a mixture containing strontium titanate as a major ingredient) and 0.1 to 1.0 mol % of Er.sub.2 O.sub.3, Ho.sub.2 O.sub.3 or mixtures thereof. In a preferred composition 0.02 to 0.2 mol % of at least one of MnO.sub.2, Co.sub.2 O.sub.3 or mixtures thereof are included. Non-linear resistors produced using the composition are comparable to those produced from conventional ceramic compositions in the threshold level voltage and non-linear factor but have greatly improved flexural strength.

Non-linear electrical resistor having varistor characteristics

A boundary layer type semiconducting ceramic capacitor with high capacitance is disclosed. The capacitor comprises a semiconducting ceramic body in which grain boundaries on crystal grains of the semiconducting ceramic body are insulated, characterized in that said semiconducting ceramic body has a composition consisting essentially of 98.1 to 99.88 mole % of a main component (Sr.sub.1-x Ba.sub.x)Tio.sub.3 or (Sr.sub.1-x Ba.sub.x)TiO.sub.3 modified with a titanete and/or a zirconate, wherein x is a mole fraction of Ba and takes a value ranging from 0.30 to 0.50, and 0.1 to 1.0 mole % of at least one semiconductorizing agent selected from the group consisting of rare earth elements, Nb, Ta and W, and that said grain boundaries of the crystal grains are insulated by at least one insulating agent selected from the group consisting of Mn, Bi, Cu, Pb, B and Si, and that the maximum crystal grain present in the semiconducting ceramic body has a grain size ranging from 100 to 250.mu.. The composition contains 0.02 to 0.2 mole % of Mn as a mineralizing agent or insulating agent. The composition may further contain at least one of 0.05 to 0.5 mole % of SiO.sub.2 and 0.02 to 0.2 mole % of Al.sub.2 O.sub.3.

Boundary layer type semiconducting ceramic capacitors with high

A method for producing boundary layer semiconductor ceramic capacitors comprises firing shaped bodies of a semiconductor ceramic material in a neutral or reducing atmosphere, heat-treating the resultant semiconductor ceramic bodies to insulatorize crystal grain boundaries of the semiconductor ceramics, and providing opposite electrodes on surfaces of the heat-treated semiconductor ceramic bodies and is characterized in that said heat-treating is carried out by heating the semiconductor ceramic bodies together with power of an insulatorizing agent with stirring in a neutral or oxidizing atmosphere at a temperature ranging from 950.degree. to 1300.degree. C. As a semiconductor ceramic material, there may be used semiconductor ceramics of a barium titanate system, or of a strontium titanate system, or a complex semiconductor ceramic mainly comprising barium titanate or calcium titanate and strontium titanate. This method enables one to produce boundary layer semiconductor ceramics as good quality with small standard deviation and high yield.

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Nagaokakyo, Japan

Haruhumi Mandai