Murata Manufacturing Co., Ltd.

Takayuki Yao

Takehisa Sasabayashi

Megumi Fukuda

Tomoyuki Nakamura

Daiki Fukunaga

Masayuki Ishihara

Taisuke Kanzaki

Akihiro Shiota

Makoto Matsuda

Kenichi Okajima

Hideyuki Hashimoto

Yasunari Nakamura

An electronic component includes a laminate including internal electrodes alternately laminated in a lamination direction with dielectric layers interposed therebetween. The laminate includes main surfaces opposite to each other in the lamination direction, side surfaces opposite to each other in a width direction, and end surfaces opposite to each other in a length direction, and external electrodes provided on surfaces of the laminate and electrically connected to the internal electrodes. Each of the dielectric layers includes Ti and Mg. When a cross section including the length direction and the width direction of the laminate is viewed from the lamination direction, side margin portions in which the internal electrodes do not exist each include a dielectric including Ti and Mg with a molar ratio in each of the side margin portions smaller than a molar ratio of Mg to Ti included in each of the dielectric layers.

Electronic component

A multilayer ceramic capacitor that has alternately stacked dielectric layers containing, as their main constituent, a barium titanate based compound that has a perovskite-type crystal structure; and internal electrode layers with electrode defects. The internal electrode layers are 0.6 &#x3bc;m or less in thickness. The electrode defects have electrode defects containing an Al&#x2014;Si based oxide mainly containing Al and Si. The number of the electrode defects containing the Al&#x2014;Si based oxide is 30% or more in number ratio to the total number of electrode defects in the internal electrodes.

Multilayer ceramic capacitor

A dielectric ceramic that contains Al and Si, as well as a barium titanate-based compound having a perovskite type crystal structure as a primary component. The total molar amount of Al and Si is 2 to 4 parts by mole with respect to 100 parts by mole of Ti, and the content ratio of Al with respect to the total molar amount is 0.2 or less (excluding 0) on the molar ratio basis. The dielectric ceramic may also contain at least one specific rare earth element Re, such as Gd, Tb, or Dy.

Dielectric ceramic and multilayer ceramic capacitor

Provide is a laminated ceramic capacitor which can suppress the decrease in dielectric constant even when ceramic layers are further reduced in thickness. The laminated ceramic capacitor includes a laminate having a plurality of stacked ceramic layers stacked and a plurality of internal electrodes formed along interfaces between the ceramic layers; and a plurality of external electrodes formed on the outer surface of the laminate and electrically connected to the internal electrodes ceramic grains in contact with both of adjacent internal electrodes adjacent with a ceramic layer interposed therebetween are present in the ceramic layers and the internal electrodes are 0.60 &#x3bc;m or less in thickness.

Laminated ceramic capacitor

A raw ceramic portion is formed on each of first and second lateral surfaces of a raw ceramic body. The raw ceramic portions contain ceramic particles and more of at least one constituent selected from Ba, Mg, Mn, and a rare-earth element between the ceramic particles than the ceramic section of the raw ceramic body in terms of total amount. The raw ceramic body is fired with the raw ceramic portions thereon. In this way, a ceramic electronic component is obtained that has a main body left after the raw ceramic body is fired with the raw ceramic portions thereon.

Method for manufacturing ceramic electronic component, and ceramic electronic component

Provided is a laminated ceramic capacitor which produces excellent lifetime characteristics in a high-temperature loading test even when dielectric layers are reduced in thickness. The dielectric ceramic contains, as its main constituent, a compound represented by the general formula (BaCaRe)(TiM)O(where Re is at least one or more elements selected from among La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y, and M is at least one or more elements selected from among Mg, Mn, Al, Cr, and Zn), 0&#x2266;x&#x2266;0.2, 0.002&#x2266;y&#x2266;0.1, and 0.001&#x2266;z&#x2266;0.05. This dielectric ceramic has crystal grains of 20 nm or more and 150 nm or less in average grain size.

Dielectric ceramic, laminated ceramic capacitor, method for producing the dielectric ceramic, and method for manufacturing the multilayer ceramic capacitor

Provided is a laminated ceramic capacitor that can suppress the decrease in insulation resistance after a moisture-resistance loading test. It contains ceramic layers which include: main-phase grains that have a perovskite-type compound containing Ba and Ti and optionally containing Ca, Sr, Zr, and Hf; and secondary-phase grains that have an average grain size of 100 nm or more and have a Si content of 50 mol % or more per grain, the average grain boundary number, represented by (Average Thickness for Ceramic Layers)/(Average Grain Size for Main Phase Grains)&#x2212;1, is greater than 0 and 3.0 or less, and the average grain size for the secondary-phase grains is &#xbc; or more of the average thickness for the ceramic layers

A dielectric ceramic capacitor that has excellent reliability and particularly excellent life characteristics in a load test even when the thickness of a dielectric ceramic layer is reduced uses a dielectric ceramic as a dielectric ceramic layer in a laminated ceramic capacitor which is a substance containing, as the main component, (Ba, R)(Ti, V)Oor (Ba, Ca, R)(Ti, V)Oin which R is at least one selected from La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y, and in which both V and R are present uniformly in the main component particles.

Dielectric ceramic and laminated ceramic capacitor

A laminated ceramic capacitor which provides favorable life characteristics, even when a high electric field strength is applied while dielectric ceramic layers are reduced in layer thickness to less than 1 &#x3bc;m, contains a dielectric ceramic a compound represented by: (BaCa)TiO(0&#x2266;x&#x2266;20) as its main constituent, and as its accessory constituent, aMg-bSi-cMn-dR (R is at least one of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y, and a, b, c, and d (part by mol) respectively satisfy the conditions of 0.1&#x3c;a&#x2266;20.0, 0.5&#x3c;b&#x2266;20.0, 0.1&#x3c;c&#x2266;10.0, and 1.0&#x3c;d&#x2266;30.0 with respect to 100 parts by mol of the main constituent). The average grain size is 20 nm or more and less than 100 nm for crystal grains in a sintered body obtained by firing the dielectric ceramic.

A dielectric ceramic which is capable of achieving a laminated ceramic capacitor with high reliability, in particular, favorable lifetime characteristics in a load test, even when a dielectric ceramic layer is reduced in thickness contains one of (Ba,R)(Ti,Mn)Oand (Ba,Ca,R)(Ti,Mn)O(R being La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and/or Y) as a main component, and M (M being Fe, Co, V, W, Cr, Mo, Cu, Al, and/or Mg) and Si as accessory components. The area of a region in which M is present is 10% or less on average of a cross section of each main component grain.

A dielectric ceramic which is capable of achieving a laminated ceramic capacitor with high reliability, in particular, favorable lifetime characteristics in a load test, even when a dielectric ceramic layer is reduced in thickness, contains one of Ba(Ti, Mn)Oand (Ba, Ca)(Ti, Mn)Oas a main component, and R (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and/or Y), M (Fe, Co, V, W, Cr, Mo, Cu, Al, and/or Mg) and Si as accessory components. The area of a region in which at least one of R and M is present is 10% or less on average on a cross section of each main component grain.

A monolithic ceramic capacitor includes dielectric ceramic layers having a thickness of less than 1 &#x3bc;m. When this thickness is t and the crystal grains of a dielectric ceramic of the layers have a mean diameter of r, a mean number N of grain boundaries satisfies 0&#x3c;N&#x2266;2 where N=t/r&#x2212;1. The dielectric ceramic contains, as a main component, a perovskite type compound ABO(where A is Ba or Ba and at least one of Ca and Sr, B is Ti or Ti and at least one of Zr and Hf), and further contains Mn and V as auxiliary components. On the basis of 100 molar parts of the main component, the content of Mn is 0.05 to 0.75 molar parts, the content of V is 0.05 to 0.75 molar parts, and the total content of Mn and V is 0.10 to 0.80 molar parts.

Monolithic ceramic capacitor

A dielectric ceramic contains a BaTiO-based compound as a main ingredient, and can be represented by the general formula: 100ABO+aNiO+bRO+cMO+dMgO+eXOwhere R represents a rare earth element such as Dy, M represents a metal element such as Mn, and X represents a sintering aid component containing Si. Ni is uniformly solid-solved in crystal grains, and the solid-solution region of the rare earth element in the crystal grains is an average 10% or less in terms of a cross section ratio. 0.96&#x2266;m&#x2266;1.030, 0.05&#x2266;a&#x2266;3, 0.1&#x2266;b&#x2266;1.5, 0.1&#x2266;c&#x2266;1.0, 0.1&#x2266;d&#x2266;1.5, and 0.05&#x2266;e&#x2266;3.5 are satisfied. A laminated ceramic capacitor has dielectric layers formed of the dielectric ceramic. As a result, a dielectric ceramic, and a laminated ceramic capacitor having excellent AC voltage characteristics, capable of keeping desired dielectric characteristics and excellent temperature characteristics, and having excellent withstand voltage and capable of ensuring reliability can be realized.

Dielectric ceramics, and laminated ceramic capacitor

A dielectric ceramic represented by a general formula: 100BaTiO+aRO+bMO+cXO(where R represents a rare earth element, M represents a predetermined metal element, and n, v, and w represent independently a positive number determined in accordance with the valences of the elements R and M and a sintering aid component X, respectively), and the solid solution regions of the secondary components in the main phase grains are 10% or less (including 0%) on average in terms of a cross-sectional area ratio. The sintering aid component X contains at least Si, and m, a, b, and c satisfy 0.995&#x2266;m&#x2266;1.030, 0.1&#x2266;a&#x2266;2.0, 0.1&#x2266;b&#x2266;3.0, and 0.1&#x2266;c&#x2266;5.0. In a monolithic ceramic capacitor, dielectric layers are formed from the above-described dielectric ceramic. Consequently, a dielectric ceramic having a good AC voltage characteristic, maintaining a desired large dielectric constant and a good temperature characteristic, exhibiting a small dielectric loss, and being capable of ensuring the reliability and a monolithic ceramic capacitor including the dielectric ceramic are realized.

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Nagaokakyo, Japan

Takayuki Yao