Murata Manufacturing Co., Ltd.

Murata Manufacturingco., Ltd.

Takashi Hiramatsu

Yukio Hamaji

Nobuyuki Wada

Jun Ikeda

Hiroyuki Wada

Yoshito Saito

Yosuke Hirata

Hideaki Tsuji

Harunobu Sano

Kunihiko Hamada

Nagato Omori

Hiroyuki Ukai

Tomoyuki Nakamura

Akira Kato

Masahiro Otsuka

Takehisa Sasabayashi

Toshihiro Okamatsu

Teppei Akiyoshi

Tomonori Muraki

Kazuo Muto

Masamitsu Shibata

A method for manufacturing a laminated ceramic capacitor having a laminated body including a plurality of stacked ceramic layers and internal electrodes located between the ceramic layers. The laminated body has a pair of mutually opposed principal surfaces extending in the direction in which the ceramic layers extend, a pair of mutually opposed side surfaces and a pair of mutually opposed end surfaces which respectively extend in directions orthogonal to the principal surfaces. The internal electrodes are 0.4 &#x3bc;m or less in thickness, and are located in an area defined by a width-direction gap of 30 &#x3bc;m or less interposed with respect to each of the pair of side surfaces and an outer layer thickness of 35 &#x3bc;m or less interposed with respect to each of the pair of principal surfaces.

Laminated ceramic electronic component

A multilayer ceramic electronic component that has a multilayer portion having an outer layer portion adjacent region including an area in contact with an outer layer portion that forms a thermal-shock absorbing portion that includes curved ceramic layers and inner electrode layers smoothly varying in thickness from point to point. A region to an inside of the thermal-shock absorbing portion forms a normal multilayer portion that includes ceramic layers with less curvature than the ceramic layers in the thermal-shock absorbing portion and inner electrode layers with less variation in thickness from point to point in a direction along a principal surface of the outer layer portion than the inner electrode layers in the thermal-shock absorbing portion.

Multilayer ceramic electronic component

In a ceramic electronic component, a first internal electrode includes a first opposed section and a first extraction section. The first opposed section is opposed to a second internal electrode with a ceramic layer interposed therebetween. The first extraction section is located closer to a first end surface than the first opposed section. The first extraction section is connected to a first external electrode. The number of cross-linked sections per unit area in the first extraction section is less than the number of cross-linked sections per unit area in the first opposed section.

Method for manufacturing ceramic electronic component and ceramic electronic component including cross-linked section

A laminated body is divided into a large grain region and a small grain region. The large grain region is located outside the small grain region, and a boundary surface between the regions is located inside the outer surface of the laminated body while surrounding a section in which internal electrodes are present in the laminated body. To obtain the laminated body, firing is carried out with a profile in which the average rate of increase from room to the maximum temperature is 40&#xb0; C./second or more.

Laminated ceramic electronic component and manufacturing method therefor

A laminated ceramic capacitor including a laminated body having a plurality of stacked ceramic layers and internal electrodes located between the ceramic layers. The internal electrodes have a plurality of ceramic columnar members formed therein, which project into the internal electrodes from interfaces between the ceramic layers and the internal electrodes, but do not penetrate in the thickness direction of the internal electrodes.

In a ceramic electronic component, a section of a first extraction section located closer to a first end surface defines a first thick section. The first thick section is at least about 1.5 times as thick as a first central section of a first opposed section in a direction. The length of the first thick section is within the range of about &#xbc; to about &#xbe; of a distance from a tip of a second opposed section closer to the first end surface, to the first end surface in the direction.

Ceramic electronic component including internal electrode with thick section

Changes in states giving rise to electrode breakage and ball formation are made less likely during firing step for sintering the laminated body, and the improvement in DC bias characteristics is achieved in laminated ceramic electronic components with a laminated body which has internal electrodes, even when ceramic layers and the internal electrodes are reduced in thickness. The laminated body is divided into a large grain region in which the ceramic has a relatively large grain diameter and a small grain region in which the ceramic has a relatively small grain diameter. The large grain region is located outside the small grain region, and a boundary surface between the large grain region and the small grain region is located inside the outer surface of the laminated body while surrounding a section in which the internal electrodes are present in the laminated body. In order to obtain the laminated body, a heat treatment is carried out in the firing step with a temperature profile in which the average rate of temperature increase from room temperature to the maximum temperature is 40&#xb0; C./second or more.

A dielectric ceramic is provided having a high relative dielectric constant, and in the case in which it is used for a multilayer ceramic capacitor, high insulating properties and superior reliability can be obtained even when the thickness of a dielectric ceramic layer is decreased. The dielectric ceramic used for forming the dielectric ceramic layer of a multilayer ceramic capacitor has a composition represented by 100 (BaCaSrGd)(TiZrHfMg)O+pMnO+qSiO+rCuO, in which 0.995&#x2266;k&#x2266;1.010, 0&#x2266;w&#x3c;0.04, 0&#x2266;x&#x2266;0.04, 0&#x2266;y&#x2266;0.10, 0&#x2266;z&#x2266;0.05, 0.015&#x2266;m&#x2266;0.035, 0.015&#x2266;n&#x2266;0.035, 0.01&#x2266;p&#x2266;1.0, 0.5&#x2266;q&#x2266;2.5, and 0.01&#x2266;r&#x2266;5.0. In addition, a is a value selected with respect to the deviation from 3 so that the primary component is electrically neutral.

Dielectric ceramic and multilayer ceramic capacitor

A dielectric ceramic material comprising the composition: 100(BaCa)TiO+aMnO+bCuO+cSiO+dMgO+eRO (wherein coefficients 100, a, b, c, d, and e each represent mols; m represents the molar ratio of (BaCa) to Ti; and RO represents at least one rare-earth element oxide selected from YO, LaO, 2CeO, NdO, SmO, EuO, GdO, TbO, DyO, HoO, ErO, TmO, YbOand LuO), wherein m, x, a, b, c, d, and e satisfy the relationships: 0.998&#x2266;m&#x2266;1.030, 0.04&#x2266;x&#x2266;0.15, 0.01&#x2266;a&#x2266;5, 0.05&#x2266;b&#x2266;5, 0.2&#x2266;c&#x2266;8, 0.05&#x2266;d&#x2266;3.0, and 0.05&#x2266;e&#x2266;2.5, and the dielectric ceramic material has an average grain size of 0.3 &#x3bc;m to 0.7 &#x3bc;m, is used to make reliable multilayer ceramic capacitors including dielectric ceramic layers each having a small thickness of about 1 &#x3bc;m.

Dielectric ceramic material and multilayer ceramic capacitor

The dielectric ceramic has a composition represented by general formula 100(BaSrCa)(TiZr)O+aBaO+bRO+cMgO+dMnO+eCuO+fVO+gXO(where R is a rare-earth element such as La, Ce or Pr; and XOis an oxide group including at least Si); and 0&#x2266;x&#x2266;0.05, 0&#x2266;y&#x2266;0.08 (preferably 0.02&#x2266;y&#x2266;0.08), 0&#x2266;z&#x2266;0.05, 0.990&#x2266;m, 100.2&#x2266;(100 m+a)&#x2266;102, 0.05&#x2266;b&#x2266;0.5, 0.05&#x2266;c&#x2266;2, 0.05&#x2266;d&#x2266;1.3, 0.1&#x2266;e&#x2266;1.0, 0.02&#x2266;f&#x2266;0.15, and 0.2&#x2266;g&#x2266;2. With this composition, a monolithic ceramic capacitor retaining good dielectric characteristics and temperature characteristics even if a high field strength voltage is applied by further thinning the dielectric layers thereof and having excellent reliability achieving good isolating property, dielectric strength, and high-temperature load life is obtained.

Dielectric ceramic and monolithic ceramic capacitor

Provided is a dielectric ceramic composition represented by the chemical composition formula: 100 (BaCa)TiO+aMnO+bCuO+cSiO+dReO(wherein coefficients 100, a, b, c, and d each represent a molar amount; and Re represents at least one element selected from Y, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb), wherein m, x, a, b, c, and d satisfy the respective relationships: 0.990&#x2266;m&#x2266;1.030, 0.04&#x2266;x&#x2266;0.20, 0.01&#x2266;a&#x2266;5, 0.05&#x2266;b&#x2266;5, 0.2&#x2266;c&#x2266;8, and 0.05&#x2266;d&#x2266;2.5.

Dielectric ceramic composition and laminated ceramic capacitor

A dielectric ceramic material containing BaTiO as a primary component and a rare earth element as an additional component, wherein the material satisfies the relation 0.7&lE;M/N so as to make the density of the rare earth metal uniform between crystal grains, and the material satisfies the relation 0.8&lE;L/M so as to make the density of the rare earth metal uniform in a crystal grain. In these relations, M represents the number of crystal grains satisfying the relation 0.5&lE;D /D; N represents the number of crystal grains constituting the ceramic material; and L represents the number of crystal grains satisfying the relations 0.5&lE;D /D and S /D &lE;0.3, wherein D represents the mean density of the rare earth element in an arbitrary crystal grain i, D represents the mean density of the rare earth element in the entirety of the ceramic material, and S represents the standard deviation of the density of the rare earth element in the crystal grain i.

Dielectric ceramic material and monolithic ceramic electronic element

The present invention provides a dielectric ceramic composition whose electrostatic capacity has an excellently low temperature dependence; which can be fired in a reducing atmosphere; and which is advantageously used in a laminated ceramic capacitor having an internal electrode formed of a base metal such as nickel or nickel alloy. The dielectric ceramic composition is represented by the following formula: &lcub;Ba Ca O&rcub; TiO &plus;&agr;MgO&plus;&bgr;MnO, wherein 0.001&lE;&agr;&lE;0.05; 0.001&lE;&bgr;&lE;0.025; 1.000<m&lE;1.035; and 0.02&lE;x&lE;0.15.

Laminated ceramic capacitor

A dielectric ceramic which exhibits small variation in dielectric constant, allows use of a base metal, can be fired in a reducing atmosphere and which is suitable for constituting a dielectric ceramic layer for, e.g., a laminated ceramic capacitor is obtained by firing barium titanate powder in which the c-axis/a-axis ratio in the perovskite structure is about 1.000 or more and less than about 1.003 and the amount of OH groups in the crystal lattice is about 2.0 wt. % or less. The barium titanate powder starting material preferably has a maximum particle size of about 0.3 &mgr;m or less and an average particle size of about 0.05-0.15 &mgr;m. Each particle of the barium titanate powder preferably comprises a low-crystallinity portion and a high-crystallinity portion, the diameter of the low-crystallinity portion being about 0.5 times or more the particle size of the powder. When sintered, the powder satisfies the ratio of (average grain size of the fired dielectric ceramic)/(average particle size of barium titanate powder starting material), R, of about 0.90-1.2, to thereby suppress considerable grain growth. A laminated ceramic electronic element including a laminate of a plurality of layers of the above-mentioned dielectric ceramic, as well as a method for producing the same, is described.

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Nagaokakyo, Japan

Takashi Hiramatsu