Murata Manufacturing Co., Ltd.

Murata Manufacturingco., Ltd.

Jun Ikeda

Yukio Hamaji

Takashi Hiramatsu

Nobuyuki Wada

Seiji Koga

Takashi Omori

Shoichiro Suzuki

Kota Zenzai

Kazuhisa Uchida

Yoshito Saito

Hiroyuki Wada

Toshikazu Takeda

Megumi Morita

A multilayer ceramic electronic component in which an interface of an edge region of an external electrode that extends around to a side surface of a ceramic body and the ceramic configuring a surface of the ceramic body, an inorganic matter is present containing 26 mol % or more and less than 45 mol % of SiOand having a molar ratio (TiO+ZrO)/(SiO+TiO+ZrO) of 0.154 or more, or an inorganic matter is present containing 45 mol % or more of SiOand having a molar ratio (TiO+ZrO)/(SiO+TiO+ZrO) of 0.022 or more. Furthermore, the inorganic matter may contain BOhaving a molar ratio relative to SiOwithin 0.25&#x2264;BO/SiO&#x2264;0.5.

Multilayer ceramic electronic component having inorganic matter at an interface between an external electrode and the ceramic body

A multilayer ceramic electronic component includes a ceramic element body including internal electrodes and external electrodes electrically connected to respective internal electrodes. Each of the external electrodes includes a sintered metal layer including glass and metal and a conductive resin layer including resin and metal particles. In a cross section of the multilayer ceramic capacitor, at an interface between the sintered metal layer and the conductive resin layer, recesses having a shape in which a dimension of an inner portion is larger than a dimension of an inlet are present, and L1/L2 is about 0.2 or more and about 1.5 or less, where L1 is a length along the interface at which the glass of the sintered metal layer is exposed at the interface, and L2 is a length along the interface at which the metal of the sintered metal layer is exposed at the interface.

Multilayer ceramic electronic component

Multilayer ceramic electronic component having an inorganic matter at an interface between an external electrode and the ceramic body

A multilayer ceramic electronic component includes a ceramic body having an end surface and a side surface adjacent to thereto such that the end surface and the side surface meet at an edge. The ceramic body has a plurality of internal electrodes with adjacent pairs of the internal electrodes being separated by a respective ceramic layer. An external electrode containing a metal, an inorganic component and voids is electrically connected to at least some of the internal electrodes and both covers the end surface and extends over the edge onto the side surface to form an extending-around portion which extends at least 50 &#x3bc;m onto the side surface as measured in a direction perpendicular to the edge and ends at a leading edge remote from the edge. A portion of the extending-around area which extends 50 &#x3bc;m from the leading edge towards the edge has an average occupancy area ratio which is at least 25 but not greater than 75. The occupancy area ratio is the ratio between the area of the conductive component and an area of the inorganic component on the one hand to the area of the conductive component, the area of the inorganic component and the area of the voids on the other.

A monolithic ceramic electronic component having outer electrodes that include an inorganic substance containing at least Si, a crystal phase C containing at least Si, Ti, and Ba at the interfaces to a ceramic layer in peripheral end portions of the outer electrodes. A value of the crystal phase area ratio indicating the relationship between the area of the crystal phase C and the area of a glass phase G, which are formed at the interface to the ceramic layer, in a region within 5 &#x3bc;m from the peripheral end portion of the outer electrode is within a range of 75% to 98%.

Monolithic ceramic electronic component and method for manufacturing the same

A multilayer ceramic electronic component includes a ceramic element body including internal electrodes and external electrodes electrically connected to respective internal electrodes. Each of the external electrodes includes a sintered metal layer including glass and metal and a conductive resin layer including resin and metal particles. In a cross section of the multilayer ceramic capacitor, at an interface between the sintered metal layer and the conductive resin layer, recesses having a shape in which a dimension of an inner portion is larger than a dimension of an inlet are present, and L/Lis about 0.2 or more and about 1.5 or less, where Lis a length along the interface at which the glass of the sintered metal layer is exposed at the interface, and Lis a length along the interface at which the metal of the sintered metal layer is exposed at the interface.

In a monolithic ceramic capacitor, ceramic layers defining inner layers are mainly composed of a perovskite compound containing Ba and Ti. A portion of an electrically effective section in the ceramic layers near a connecting portion between the inner electrodes and an outer electrode undergoes mapping analysis by an energy-dispersive method. In regions of the resulting mapping image, the regions extending from the interfaces between the inner electrodes and a corresponding one of the ceramic layers to positions about &#x2153; of the thickness of the ceramic layer in the stacking direction, ((L2&#x2212;L3)/L1)&#xd7;100&#x2267;50 is satisfied, where L1 represents the total length of grain boundaries, L2 represents the total length of grain boundaries where a rare-earth element is present, and L3 represents the total length of portions where the grain boundaries where the rare-earth element is present are overlapped with grain boundaries with a specific element present.

Monolithic ceramic capacitor containing perovskite compound

In a multilayer ceramic capacitor, an inner ceramic layer includes a perovskite-type compound containing Ba and Ti. A region within an electrically effective portion of the inner ceramic layers sandwiched between inner electrodes, which is near an area where inner and outer electrodes connect to each other, is subjected to a mapping analysis using EDS. ((L&#x2212;L)/L)&#xd7;100&#x2267;50 is satisfied, Ldenotes a total length of ceramic grain boundaries detected from a TEM transmission image, Ldenotes a total length of grain boundaries, detected from a mapping image and the TEM transmission image, where the rare earth element is present, and Ldenotes a total length of portions, detected from a mapping image and the TEM transmission image, in which the grain boundaries where the rare earth element is present and grain boundaries where at least one of Mn, Mg, and Si is present are overlapped.

Multilayer ceramic capacitor having high moisture resistance

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

Provided are a dielectric ceramic composition suitable for use in a monolithic ceramic capacitor that is employed in high-temperature environments such cars, and a monolithic ceramic capacitor constituted by using the dielectric ceramic composition. The dielectric ceramic composition has a composition formula of 100(BaCa)TiO+aRO+bVO+cZrO+dMnO (where R is at least one metal element selected from among Y, La, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm and Yb, and a, b, c and d denote values in terms of moles), and conditions of 0.03&#x2266;x&#x2266;0.20, 0.05&#x2266;a&#x2266;3.50, 0.22&#x2266;b&#x2266;2.50, 0.05&#x2266;c&#x2266;3.0, and 0.01&#x2266;d&#x2266;0.30 are substantially satisfied. The dielectric ceramic layers in the monolithic ceramic capacitor are made of a sintered compact of the dielectric ceramic composition.

Dielectric ceramic composition and monolithic ceramic capacitor

There is provided a dielectric ceramic composition suitable for, for example, a car-mounted monolithic ceramic capacitor used in a high-temperature environment. It is represented by the composition formula: 100(BaCa)TiO+aMgO+bVO+cSiO+dROwherein R represents at least one metal element selected from Y, La, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb; and a, b, c, and d each represent a moles. The dielectric ceramic composition satisfying the requirements of 0.03&#x2266;x&#x2266;0.20, 0.99&#x2266;m&#x2266;1.03, 0.10&#x2266;a&#x2266;5.0, 0.025&#x2266;b&#x2266;2.5, 0.20&#x2266;c&#x2266;8.0, and 2.5&#x2266;d&#x3c;3.5. Dielectric ceramic layers in a monolithic ceramic capacitor are formed of a sintered body of the dielectric ceramic composition.

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

Jun Ikeda