Kyocera Corporation

Nobuyoshi Fujikawa

Seiichiro Hirahara

Yoshihiro Fujioka

Nobuo Yokoe

Toyomi Nishi

Yoshihiro Okawa

Shinji Isoyama

Kouichi Maruta

Takashi Okawa

Katsuhiko Onitsuka

Maiko Nagayoshi

Masakazu Yasui

Djuniadi Arifin Sagala

Seiichi Hirahara

Gentaro Kaji

Toshiki Okazaki

Hideki Utaki

Shinichi Enami

Teruya Fujisaki

Sumie Koyasu

Tsuguo Koyasu

Akira Hashimoto

Hiroshi Ojima

Shin-ichi Osawa

Yasushi Yamakuchi

Yuji Tateishi

Shigeji Koyasu

Akihiro Kaneuchi

Syuichi Kawaminami

Hidenori Miyata

Shinjiro Shimo

Shinji Nambu

Hirofumi Toda

Kazuyoshi Yamashita

A capacitor includes a capacitor body including a plurality of dielectric layers and a plurality of internal electrode layers being stacked alternately. The plurality of dielectric layers mainly include crystal grains containing barium titanate as a main component. The plurality of dielectric layers contain magnesium, a rare earth element, and manganese. The plurality of dielectric layers include oxide grains containing at least one of the magnesium, the rare earth element, or the manganese as a single element.

Capacitor

A capacitor according to an embodiment of the present disclosure is provided with a capacitor body in which a plurality of dielectric layers and a plurality of internal electrode layers are alternately laminated. The dielectric layers each includes crystal particles, grain boundaries and metal particles. An average particle size of the metal particles is smaller than an average particle size of the crystal particles and larger than an average width of interfacial grain boundaries among the grain boundaries. Observation of the longitudinal cross section of the dielectric layer shows that the metal particles are distributed along the width direction and the thickness direction of the dielectric layer.

A dielectric ceramic composition containing, per 100 parts by weight of BaTiO.sub.3, at least either one of Nb.sub.2 O.sub.5 or Ta.sub.2 O.sub.5 in an amount of from 0.8 to 3.5 parts by weight, MgO in an amount of from 0.06 to 0.7 parts by weight, oxides of rare earth elements in an amount of from 0.005 to 0.520 parts by weight, and MnO in an amount of from 0.01 to 0.30 parts by weight in the form of MnCO.sub.3, the molar ratio of MgO to either Nb.sub.2 O.sub.5 or Ta.sub.2 O.sub.5 being from 0.5 to 2.2. The dielectric ceramic composition has a dielectric constant of not smaller than 2500, is fired at a temperature of not higher than 1300.degree. C., exhibits a change of capacitance depending upon the temperature satisfying X7R of the IEA Standards, a dielectric loss of not larger than 2.5%, a small voltage dependence, and an insulation resistance of not smaller than 10.sup.4 M.OMEGA., and is suited as a material for producing ceramic capacitors and resonators.

Dielectric ceramic composition

A dielectric ceramic composition used for a ceramic capacitor for temperature compensation, a resonator and the like. The dielectric ceramic composition comprises a composite oxide containing, as metal elements, main components of (i) barium, (ii) rare earth elements such as neodymium (Nd) or Nd and Sm in combination, and (iii) elements of the Group IV of periodic table such as titanium (Ti) or Ti and Zr or Sn in combination, and an assistant component of manganese, wherein the main components comprise from 7.5 to 16.25 mol % of a barium oxide, from 16.75 to 23.75 mol % of an oxide of rare earth element, and from 67 to 71.66 mol % of an oxide of element of the Group IV reckoned as a molar composition of the ternary-component-based oxide, the manganese component is contained in an amount of from 0.01 to 0.5% by weight reckoned as MnCO.sub.3 with respect to the main components, and sodium component which is an impurity is contained in an amount of not larger than 0.10% by weight with respect to the whole amount.

A dielectric ceramic composition comprising main components represented by a composition formula on the weight basis, aMgO.multidot.bCaO.multidot.cTiO.sub.2, wherein a, b and c satisfy the following relationships, 25.ltoreq.a.ltoreq.35, 0.3.ltoreq.b.ltoreq.7, 60.ltoreq.c.ltoreq.70, a+b+c=100, blended with a boron-containing compound in an amount of from 3 to 20 parts by weight reckoned as B.sub.2 O.sub.3 and an alkali metal-containing compound in an amount of from 1 to 12 parts by weight reckoned as the alkali metal carbonate per 100 parts by weight of the main components, as well as a multilayer resonator made of said composition, and a filter using said resonator. The ceramic composition can be fired together with a conductor metal such as Ag or Cu at a relatively low temperature of 900.degree. to 1050.degree. C., exhibits large dielectric constant and Q-value, and a relatively small temperature coefficient .tau.f, lending itself well for use as a material for high-frequency electronic parts. The resonator made of this ceramic composition exhibits excellent tproperties in high-frequency regions, and can be realized in a small size.

Dielectric ceramic composition, multilayer resonator made of said

A dielectric ceramic composition for high-frequency applications comprising a composite oxide containing at least Ba, Zn and W as metal elements. When the composition formula of the composite oxide is expressed in the form of molar ratios of the metal oxides, the molar ratios of the metal oxides lie within particular ranges. The ceramic composition exhibits a high dielectric constant and a large Q-value in high-frequency regions.

Dielectric ceramic composition for high-frequency applications

A dielectric ceramic composition for high frequency-use comprising a composition (A) containing at least Ba, Mg and W as metal elements represented by a composition formula expressed in a mole ratio of these metal elements, xBaO.yMgO.zWO.sub.3, in which x, y and z satisfy the following relation

Dielectric ceramic composition for high frequency

In a dielectric ceramic composed of a La.sub.2 O.sub.3 -CaO-TiO.sub.2 -MgO type or a BaO-Nd.sub.2 O.sub.3 -TiO.sub.2 type, the oxygen vacancy concentration of the ceramic is controlled below 7.times.10.sup.18 /cm.sup.3 by, for example, annealing the mixture after firing, or heat-treating the mixture after firing. The Q value of the dielectric ceramic can be markedly increased. In addition, ceramics having stable properties can be produced. Thus, the dielectric ceramics can fully cope with high frequencies and large electrification.

Dielectric ceramic for microwaves

A dielectric ceramic composition which contains a rare earth element (Ln), Al, Ca and Ti as metal elements and which when these components are expressed in terms of a mole ratio as aLn.sub.2 O.sub.x.bAl.sub.2 O.sub.3. cCaO.dTiO.sub.2, the values of a, b, c, d and x satisfy a+b+c+d=1, 0.056.ltoreq.a.ltoreq.0.214, 0.056.ltoreq.b.ltoreq.0.214, 0.286.ltoreq.c.ltoreq.0.500, 0.230.ltoreq.d.ltoreq.0.470, and 3.ltoreq.x.ltoreq.4. The dielectric having the above composition is disposed between a pair of input and output terminals to constitute a dielectric resonator. The dielectric ceramic composition exhibits such dielectric properties as a large dielectric constant at high frequencies, a large Q-value and a small temperature coefficient of resonance frequency. Satisfactory properties are exhibited when the dielectric ceramic composition is used for a resonator or as a material of circuit board for high-frequency applications.

Dielectric ceramic composition and dielectric resonator

A dielectric material for high frequency having a composition formula xBaO.yMgO.zWO.sub.3, a composition formula xSrO.yMgO.zWO.sub.3 or a composition formula xBaO.yMgO.zWO.sub.3.wTaO.sub.5/2 wherein x, y, z and w have a specified relationship. It has a high inductivity and a high Q value in a high frequency region especially a microwave and a milliwave.

Dielectric ceramic composition for high-frequency use and dielectric

A dielectric ceramic composition having a composition (mole %) expressed by the formula xMgO.yLa.sub.2 O.sub.3. xTiO.sub.2 wherein x, y and z are numerals that lie within a range surrounded by a line that couples the points a, b, c, d and e in FIG. 1. The composition can contain 0.01 to 3% by weight of MnO.sub.2 with respect to chief components consisting of the above three components. The composition can be effectively used as a resonator or a circuit board in the microwave frequency region.

Dielectric ceramic composition for high frequency use

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 multilayer ceramic capacitor comprising internal electrodes composed of nickel and terminations composed of a composition comprising at least one member selected from nickel, cobalt and copper and a zinc borosilicate glass. A zinc borosilicate glass comprising 40 to 65 mole % of ZnO, 20 to 40 mole % of B.sub.2 O.sub.3 and 10 to 35 mole % of SiO.sub.2 is especially suitable as the glass component. The terminations are excellent in adhesion to the internal electrodes and adhesion to a dielectric body.

Multilayer ceramic capacitor

A dielectric ceramic composition prepared by adding 0.1 to 1.3% of B.sub.2 O.sub.3, 1.0 to 3.0% of SiO.sub.2 and 0.5 to 3.0% of ZnO to a composition comprising 18.0 to 27.0% of BaTiO.sub.2, 31.6 to 36.3% of Nd.sub.2 O.sub.3, 27.6 to 35.5% of TiO.sub.2, 2.5 to 8.1% of Bi.sub.2 O.sub.3 and 5.6 to 9.0% of Pb.sub.3 O.sub.4, all percentages being by weight. This dielectric composition has a high dielectric constant and a temperature coefficient controlled within a narrow range and can be fired at relatively low temperatures. Because of these properties, it is used as a multilayer ceramic capacitor in combination with an electrode composed of an Ag-Pd alloy containing a major amount of Ag.

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Kokubu, Japan

Nobuyoshi Fujikawa