Murata Manufacturing Co., Ltd.

Murata Mfg. Co., Ltd.

Norihiko Sakamoto

Harunobu Sano

Hiroyuki Wada

Yukio Hamaji

Takaharu Miyazaki

Nobuyuki Wada

Shinobu Mizuno

Tomoro Abe

Kenichi Yamada

Tomoo Motoki

A highly reliable multilayer ceramic electronic device is obtained while preventing crack defects generated in a ceramic laminate by application of a heat shock in a mounting step or the like. The multilayer ceramic electronic device is constructed such that the average value of continuities of internal electrodes located in two regions (f) is lower by 5% to 20% inclusive than the average value of continuities of internal electrodes located in the central portion in a lamination direction. The two regions (f) are the regions from the topmost internal electrode and the bottommost internal electrode located in the lamination direction to the inside, respectively, within 10% of the distance (d) therebetween. Continuity is defined by (X&#x2212;Y)/X in which X is the length of a cross section of an internal electrode in one direction and Y indicates the sum of gaps (g) formed by pores in the cross section of the internal electrode.

Multilayer ceramic electronic device

A monolithic ceramic capacitor includes a plurality of dielectric ceramic layers, a plurality of inner electrodes formed between the dielectric ceramic layers in such a manner that one end of each inner electrode is exposed out of either end of the dielectric ceramic layers, and outer electrodes electrically connected with the exposed inner electrodes; in which the inner electrodes each are made of a base metal, and Si oxide layers or layers comprising an Si oxide and at lest one component that constitutes said dielectric ceramic layers and said inner electrodes are formed adjacent to the inner electrodes. The capacitor has excellent thermal impact resistance and wet load resistance characteristics. A producing method includes firing a green sheet laminate including a metal inner electrode at an oxygen partial pressure of about said equilibrium oxygen partial pressure of the metal to the metal oxide.

Method of producing a monolithic ceramic capacitor

An anti-reducing dielectric ceramic composition having a dielectric constant of 100 or higher and excellent reliability during a life measuring test under a high temperature load and a monolithic ceramic capacitor formed by using the improved anti-reducing dielectric ceramic composition. The composition is a composite oxide represented by the composition formula (Ca,Sr,),(Zr,Ti,)O,, 0&lE;x<0.5, 0.60<y&lE;0.85 and 0.85<m<1.30 as a main component. Every 100 mols of the main component is mixed with at least one of a manganese compound and a magnesium compound incorporated as an accessory component in a range of about 0.1 to 6 mols, by calculatively converting the manganese compound into MnO and the magnesium compound into MgO. The composition may further contain a sintering auxiliary material such as SiO,.

Anti-reducing dielectric ceramic composition and monolithic ceramic capacitor using the same

The present invention provides a dielectric ceramic composition containing 100 parts by weight of essential component represented by (BaO).sub.m TiO.sub.2 +M.sub.2 O.sub.3 +R.sub.2 O.sub.3 +BaZrO.sub.3 +MgO+MnO (wherein M.sub.2 O.sub.3 represents Sc.sub.2 O.sub.3 and/or at least one of Eu.sub.2 O.sub.3, Gd.sub.2 O.sub.3, Tb.sub.2 O.sub.3 and Dy.sub.2 O.sub.3) and 0.2 to 3.0 parts by weight of a side component represented by Li.sub.2 O--(Si, Ti)O.sub.2 --MO (wherein MO represents Al.sub.2 O.sub.3 and or ZrO.sub.2) or SiO.sub.2 --TiO.sub.2 --XO (wherein XO represents at least one of BaO, CaO, SrO, MgO, ZnO and MnO), and a ceramic capacitor using the same.

Dielectric ceramic composition and monolithic ceramic capacitor using

A monolithic ceramic capacitor has dielectric ceramic layers of a material comprising barium titanate having alkali metal oxides impurities in an amount of not more than about 0.02% by weight, manganese oxide, cobalt oxide, and nickel oxide; from about 0.5 to 5.0 mols MgO to 100 mols of a main constituent shown by the following composition formula;

Monolithic ceramic capacitor

A monolithic ceramic capacitor and producing method thereof are disclosed. The ceramic capacitor has a plurality of dielectric ceramic layers, a plurality of inner electrodes formed between the dielectric ceramic layers in such a manner that one end of each inner electrode is exposed out of either end of the dielectric ceramic layers, and outer electrodes electrically connected with the exposed inner electrodes; in which the inner electrodes each are made of a base metal, and Si oxide layers or layers comprising an Si oxide and at least one component that constitutes said dielectric ceramic layers and said inner electrodes are formed adjacent to the inner electrodes. The capacitor has excellent thermal impact resistance and wet load resistance characteristics.

A monolithic ceramic capacitor having a plurality of dielectric ceramic layers, internal electrodes, and external electrodes electrically connected to the internal electrode, wherein the dielectric ceramic layers comprise (a) barium titanate having an alkali metal oxide impurity content of not more than about 0.02% by weight, (b) scandium oxide and/or yttrium oxide, (c) gadolinium oxide, terbium oxide and/or dysprosium oxide, (d) manganese oxide, (e) cobalt oxide, and (f) nickel oxide, and is a material containing (1) 100 mols represented by the compositional formula:

Disclosed is a monolithic ceramic capacitor comprising dielectric ceramic layers made from a ceramic composition, which comprises an essential component of (1-.alpha.-.beta.){BaO}.sub.m.TiO.sub.2 +.alpha.{(1-x)M.sub.2 O.sub.3 +xRe.sub.2 O.sub.3 }+.beta.(Mn.sub.1-y-z Ni.sub.y Co.sub.z)O (0.0025.ltoreq..alpha..ltoreq.0.025; 0.0025.ltoreq..beta..ltoreq.0.05; .beta./.alpha..ltoreq.4; 0&lt;x.ltoreq.0.50; 0.ltoreq.y&lt;1.0; 0.ltoreq.z&lt;1.0; 0.ltoreq.y+z&lt;1.0; 1.000&lt;m.ltoreq.1.035) and from 0.5 to mols, relative to 100 mols of the essential component, of a side component MgO, and contains from 0.2 to 3.0 parts by weight, relative to 100 parts by weight of said components, of an oxide of the type of Li.sub.2 O--(Si,Ti)O.sub.2 --Al.sub.2 O.sub.3 --ZrO.sub.2. The capacitor can be small-sized while having large capacity. It can be produced even through baking in atmospheres having a low oxygen partial pressure without producing semiconductors. It has a dielectric constant of 3000 or more, and has an insulating resistance of 6000 .OMEGA..F or more, which is lowered little even in strong electric fields. It has good reliability and has a high rated voltage even when its dielectric layers are thinned, and has temperature-dependent capacitance that satisfies the B-level characteristic standard stipulated in the JIS Standard and the X7R-level characteristic standard stipulated in the EIA Standard. It has excellent weather resistance even under a load of high temperature and/or a load of high humidity.

Disclosed herein is a dielectric ceramics composition which comprises 100 moles of a primary component being a barium titanate (containing less than about 0.02 wt % of alkali metal oxide as an impurity) as expressed by the compositional formula:

Disclosed is a monolithic ceramic capacitor comprising dielectric ceramic layers made from a ceramic composition, which comprises an essential component of (1-.alpha.-.beta.) {BaO}.sub.m .multidot.TiO.sub.2 +.alpha.{(1-x)M.sub.2 O.sub.3 +xRe.sub.2 O.sub.3 }+.beta.(Mn.sub.1-y-z Ni.sub.y Co.sub.z)O (0.0025.ltoreq..alpha..ltoreq.0.025; 0.0025.ltoreq..beta..ltoreq.0.05; .beta./.alpha..ltoreq.4; 0&lt;x.ltoreq.0.50; 0.ltoreq.y&lt;1.0; 0.ltoreq.z&lt;1.0; 0.ltoreq.y+z&lt;1.0; 1.000&lt;m.ltoreq.1.035) and from 0.5 to mols, relative to 100 mols of the essential component, of a side component MgO, and contains from 0.2 to 3.0 parts by weight, relative to 100 parts by weight of said components, of an oxide of the type of Li.sub.2 O--(Si,Ti)O.sub.2 --Al.sub.2 O.sub.3 --ZrO.sub.2. The capacitor can be small-sized while having large capacity. It can be produced even through baking in atmospheres having a low oxygen partial pressure without producing semiconductors. It has a dielectric constant of 3000 or more, and has an insulating resistance of 6000 .OMEGA..multidot.F or more, which is lowered little even in strong electric fields. It has good reliability and has a high rated voltage even when its dielectric layers are thinned, and has temperature-dependent capacitance that satisfies the B-level characteristic standard stipulated in the JIS Standard and the X7R-level characteristic standard stipulated in the EIA Standard. It has excellent weather resistance even under a load of high temperature and/or a load of high humidity.

A method of sintering ceramic formed bodies, in which a container for sintering is disposed in a sintering space of a sintering furnace, and atmospheric gas is introduced from an atmospheric gas inlet port provided on a bottom surface of the container for sintering into a large number of ceramic formed bodies piled up in the container for sintering, thereby to sinter the large number of ceramic formed bodies piled upon each other while introducing the atmospheric gas into spaces between the ceramic formed bodies.

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Shiga-ken, Japan

Norihiko Sakamoto