Murata Manufacturing Co., Ltd.

Toshikazu Takeda

Shoichiro Suzuki

Nobuyuki Wada

Megumi Morita

Shinichi Yamaguchi

Yukio Sakabe

Masahiko Kimura

Atsuo Senda

Takuji Nakagawa

Jun Ikeda

Kosuke Shiratsuyu

Yoshifumi Ogiso

Tomomi Koga

Yukako Takahashi

A dielectric ceramic which is suitable for use in a laminated ceramic capacitor under a high-temperature environment, such as encountered in, for example, automobile use has a composition represented by the composition formula: (1&#x2212;x) (BaCa)TiO+xCaTiO+aReO+bMgO+cMnO+dVO+eSiOin which Re is Gd, Dy, Y, Ho, and/or Er), 0.001&#x2266;x&#x2266;0.02, 0.08&#x2266;y&#x2266;0.20, 0.99&#x2266;m&#x2266;1.05, 0.01&#x2266;a&#x2266;0.04, 0.005&#x2266;b&#x2266;0.035, 0&#x2266;c&#x2266;0.01, 0&#x2266;d&#x2266;0.01, 0.01&#x2266;e&#x2266;0.04 when a, b, c, d, and e are each expressed in terms of parts by mol with respect to 1 mol of (1&#x2212;x) (Ba,Ca)TiO+xCaTiO. This dielectric ceramic can constitute the dielectric ceramic layers of a laminated ceramic capacitor.

Dielectric ceramic and laminated ceramic capacitor

A method for manufacturing a piezoelectric element that includes a piezoelectric ceramic body containing an internal electrode. The piezoelectric ceramic body is mainly made of a perovskite complex oxide containing an alkali metal niobate-based compound containing at least one element selected from among K, Li, and Na. The internal electrode is made of a base metal material, such as Ni or Cu. The piezoelectric element is produced by co-sintering the internal electrode and the piezoelectric ceramic body in a reducing atmosphere.

Method of manufacturing a piezoelectric element

A dielectric ceramic which improves the lifetime characteristics and dielectric breakdown voltage of a laminated ceramic capacitor includes core-shell crystalline grains which have a core-shell structure and homogeneous crystalline grains which have a homogeneous structure. In this dielectric ceramic, the core-shell crystalline grains and the homogeneous crystalline grains are present at an area ratio in the range of 91:9 to 99:1. Preferably, when the mean grain size for the core-shell crystalline grains is represented by R1 and the mean grain size for the homogeneous crystalline grains is represented by R2, the ratio of R2/R1 is 0.8 or more and 3 or less.

A dielectric ceramic for use in dielectric ceramic layers has a main component represented by a composition formula of (SrSnBa)TiO, wherein x is 0.005&#x2266;x&#x2266;0.24, y is 0&#x2266;y&#x2266;0.25 in the composition formula. Preferably, the dielectric ceramic includes 0.01 mol to 5 mol of M (M is at least one of Mn and V) calculated as MO and/or 0.2 mol to 5 mol of Si calculated as SiO, with respect to 100 mols of the main component, and more preferably, further includes 0.1 mol to 25 mol of Ca calculated as CaO with respect to 100 mols of the main component. The dielectric ceramic has an increased dielectric constant permitting size reduction when used in a laminated ceramic capacitor.

A dielectric ceramic with stable insulation properties even after calcination under a reducing atmosphere, as is preferred for a laminated ceramic capacitor, is a CaTiOcomposition containing Sn. It is preferable for the dielectric ceramic to contain, as its main component, (CaBaSn)TiO(0&#x2266;x&#x3c;0.2, 0.01&#x2266;y&#x3c;0.2) with a solution of Sn at the B site.

There is provided a dielectric ceramic composition that is a dielectric ceramic material used for a laminated ceramic capacitor; that can be co-fired with internal electrodes mainly composed of Ni at a temperature of 1300&#xb0; C. or less; and that has a high dielectric constant, good temperature characteristics of capacitance in a range of &#x2212;55 to 175&#xb0; C., and a high resistivity &#x3c1; at 175&#xb0; C. The dielectric ceramic composition includes a main component represented by a composition formula (1-a) (KNa)(SrBaCa)NbO-a(BaCa)TiO(where a, b, x, y, and z are all molar amounts and 0.3&#x2266;a&#x2266;0.8, 0&#x2266;b&#x2266;0.2, 0&#x2266;x&#x3c;0.2, 0.1&#x2266;y&#x2266;0.5, 0.1&#x2266;z&#x2266;0.5, and 0.2&#x2266;y+z&#x2266;0.7); and M, as an additional component, in an amount of 0.1 to 40 parts by mole relative to 100 parts by mole of the main component (where M is at least one element from the group of V, Mn, Cr, Fe, Co, Ni, Zn, Mg, and Si).

Dielectric ceramic composition and laminated ceramic capacitor

A dielectric ceramic composition that is used for a monolithic ceramic capacitor, can be cofired with internal electrodes mainly composed of Ni at a temperature of 1200&#xb0; C. or less, and has a high resistivity is provided. The dielectric ceramic composition is mainly composed of a tungsten bronze type complex oxide having a composition formula of (KNa)SrNbO(wherein 0&#x2266;x&#x3c;0.2) and further contains, as accessory components, 0.05 to 20 molar parts of R (wherein R is at least one selected from the group consisting of Y, La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) and 0.05 to 40 molar parts of M (wherein M is at least one selected from the group consisting of Mn, V, Li, Si, Ni, Cr, Co, Fe, Zn, Mg, and Zr) per 100 molar parts of the main component.

Dielectric ceramic composition and monolithic ceramic capacitor

The piezoelectric ceramic composition of the present invention contains a main component represented by general formula {(1-n)(AgLi)(NbTa)O-n(M1,M2)M3M3O} or {(1-n)(AgLi)(NbTa)O-nM4M5O} and x, y, m, and n are defined to be 0.075&#x2266;x&#x3c;0.40, 0&#x2266;y&#x3c;0.2, 0.98&#x2266;m&#x2266;1.0, and 0.01&#x2266;n&#x2266;0.1. M1 is a trivalent metal element such as Bi; M2 is a monovalent metal element such as K, Na, Li or Ag; M3 and M5 each are a tetravalent metal element such as Ti, Zr, Sn or Hf; and M4 is a divalent metal element such as Ba, Sr, Ca, or Mg. With this composition, an highly reliable lead-free piezoelectric ceramic composition having a high relative dielectric constant and good piezoelectric properties such as electromechanical coupling factor kand piezoelectric constant dcan be provided, and a highly reliable lead-free piezoelectric element can be fabricated using the piezoelectric ceramic composition.

Piezoelectric ceramic composition and piezoelectric element

A dielectric ceramic composition of the present invention contains, as a main component, a tungsten-bronze-type composite oxide represented by a composition formula (KNa)SrNbO(wherein 0&#x2266;y&#x3c;0.2) and, as an auxiliary component, Mn in an amount in the range of 0.1 to 40 parts by mole relative to 100 parts by mole of the main component.

The present invention provides a method of efficiently manufacturing a dielectric waveguide with high reliability and precision. In the method, a resist material is formed on the outer surface of a green compact provided with a removal inhibiting layer, and predetermined portion of the green compact defined by the resist material is removed by the sand blasting method using the resist material as a mask, until the removal inhibiting layer is exposed to obtain a shaped green compact structure. The thus-obtained structure is fired to obtain a sintered body which comprises a dielectric strip and a wing.

Method of manufacturing a dielectric waveguide

A method for manufacturing a dielectric waveguide at a low manufacturing cost, the dielectric waveguide comprising a pair of conductor plates approximately parallel to each other and the dielectric strip provided therebetween, which can form a dielectric strip having accurate individual dimensions without generating cracks and chips during processing. The method comprises the steps of forming a resist pattern on a green sheet containing at least a powdered inorganic material and an organic binder, removing a predetermined amount of the green sheet corresponding to an opening in the resist pattern by the use of a mask, removing the resist pattern, and firing the green sheet. In the step of removing the predetermined amount of the green sheet, the rate of removal is continuously or intermittently changed along the depth direction of the green sheet.

Method for manufacturing dielectric wave guide

Method of manufacturing the dielectric waveguide

A piezoelectric ceramic composition is provided that does not contain Pb, and yet has a large electromechanical coupling coefficient in comparison with a bismuth layered compound, as well as a piezoelectric ceramic element using the composition. This piezoelectric ceramic composition includes at least the elements Ag, Li, Nb, and O, and has an electromechanical coupling coefficient k of not less than about 20%.

Piezoelectric ceramic composition and piezoelectric ceramic element using the same

Disclosed herein is a method of preparing an InSb thin film, which comprises a step of physically sticking InSb powder onto a major surface of a substrate, and a step of depositing an InSb thin film on the major surface of the substrate provided with the as-stuck InSb powder by a method such as vacuum evaporation.

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Omihachiman, Japan

Toshikazu Takeda