Taiyo Yuden Co., Ltd.

Kazumichi Hiroi

Chie Kawamura

Kotaro Mizuno

Yukihiro Konishi

Minoru Ryu

Yusuke Kowase

Osamu Hattori

Ayumu Sato

Koichiro Morita

Norihiro Arai

Hirokazu Shimizu

Katsuya Taniguchi

Yasuyuki Inomata

Yoshiki Iwazaki

Kunihiko Nagaoka

A multilayer ceramic electronic component includes a ceramic body, which includes an electrode-stacking portion in which internal electrodes are stacked, and cover portions facing each other in a first axis direction across the electrode-stacking portion, and external electrodes each including a covering portion that covers the ceramic body from a second axis direction, and an extending portion that extends over the cover portions along the second axis direction. The ceramic body includes crystal grains of ceramic and segregated small grains located between the crystal grains. In a cross section of an end section located between the extending portion of the cover portion and the electrode-stacking portion, the number of the segregated small grains having a grain size of 0.5% or greater and 10% or less of an average grain size of the crystal grains is 40% or greater and 95% or less of the number of the crystal grains.

Multilayer ceramic electronic component

A ceramic electronic device includes a multilayer structure in which a plurality of dielectric layers and a plurality of internal electrode layers are alternately stacked. Each of the plurality of dielectric layers includes ceramic grains of a main component thereof expressed by (BaCaSr)(TiZr)O(0<x≤0.2, 0≤y≤0.1, 0≤z≤0.1). D3<D1<D2 is satisfied when an average grain diameter of the ceramic grains of the main component of the plurality of dielectric layers in a section in which each two internal electrode layers is D1, an average grain diameter of the ceramic grains of the main component of first dielectric layers which are located at different height positions from the internal electrode layers is D2, an average grain diameter of the ceramic grains of the main component of second dielectric layers which are located at same height positions of the internal electrode layers is D3.

Ceramic electronic device and manufacturing method of the same

A manufacturing method of ceramic powder includes mixing a barium carbonate having a specific surface are of 15 m/g or more, a titanium dioxide having a specific surface area of 20 m/g or more, a first compound of a donor element having a larger valence than Ti, and a second compound of an acceptor element having a smaller valence than Ti and having a larger ion radium than Ti and the donor element, and synthesizing barium titanate powder by calcining the barium carbonate, the titanium dioxide, the first compound and the second compound until a specific surface area of the barium titanate powder becomes 4 m/g or more and 25 m/g or less.

Manufacturing method of ceramic powder

A manufacturing method of ceramic powder includes: synthesizing barium titanate powder from barium carbonate, titanium dioxide, manganese carbonate, and one of ammonium molybdate and tungsten oxide, wherein: a solid solution amount of the donor element is 0.05 mol or more and 0.3 mol or less; a solid solution amount of the accepter element with respect to the barium titanate is 0.02 mol or more and 0.2 mol or less on a presumption that the amount of the barium titanate is 100 mol and the acceptor element is converted into an oxide; and relationships y&#x2265;&#x2212;0.0003x+1.0106, y&#x2264;&#x2212;0.0002x+1.0114, 4&#x2264;x&#x2264;25 and y&#x2264;1.0099 are satisfied when a specific surface area of the ceramic powder is 'x' and an axial ratio c/a of the ceramic powder is 'y'.

Dielectric layers are prepared using a dielectric material that contains a ceramic powder having Ba, Ti, and additive element X which is solid-solubilized and is at least one element selected from the group consisting of Mo, Ta, Nb, and W, wherein the standard deviation of the ratio of the peak intensity of the additive element X (XK&#x3b1;) measured by STEM-EDX, and the sum of the peak intensity of the Ti and peak intensity of the Ba (BaL&#x3b1;+TiK&#x3b1;) measured by STEM-EDX, is less than 10.5% of the average ratio as measured at a total of five points including the three points that divide the maximum diameter of one grain of the ceramic powder into four equal parts, and two excluding the center point of the three points that divide the diameter crossing at right angles with the maximum diameter at its center point, into four equal parts.

Dielectric material for multilayer ceramic capacitor, and multilayer ceramic capacitor

A multilayer ceramic capacitor has a laminate comprising dielectric layers stacked alternately with internal electrode layers of different polarities, wherein: the dielectric layers contain ceramic grains whose primary component is BaTiO; the ceramic grains contain at least one type of donor element (D) selected from the group that includes Nb, Mo, Ta, and W, and at least one type of acceptor element (A) selected from the group that includes Mg and Mn; and the ratio of the concentration of the donor element (D) and that of the acceptor element (A) (D/A) is greater than 1 at the center parts of the ceramic grains, while the D/A ratio is less than 1 at the outer edge parts of the ceramic grains (if A=0, then D/A=&#x221e; and D=A=0 never occurs).

Multilayer ceramic capacitor

A laminated ceramic electronic component has electrode layers stacked with ceramic layers, where the thickness of each electrode layer is controlled to 0.5 &#x3bc;m or less and the average size of crystal grains constituting the electrode layer is controlled to 0.1 &#x3bc;m or less. The occurrence of structural defects in the laminated ceramic electronic component can be suppressed and high continuity of the electrode layers stacked with the ceramic layers is ensured.

Laminated ceramic electronic component

A dielectric ceramic whose primary component is an ABOcompound (A contains Ba and B contains Ti) has a per-layer thickness of approx. 0.5 &#x3bc;m or less, where the volume ratio to all dielectric sintered grains of those whose grain size is in a range of 0.02 &#x3bc;m to 0.15 &#x3bc;m is adjusted to a grain size distribution of 1% to 10%. High dielectric constant and high reliability can be achieved at the same time with the dielectric ceramic.

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Takasaki, Japan

Kazumichi Hiroi