Nippon Soken, Inc.

Denso Corporation

Other

Toyota Jidosha Kogyo Kabushiki Kaisha

Eturo Yasuda

Minoru Ohta

Yoshihiro Segawa

Hitoshi Shindo

Toshiatsu Nagaya

Takashi Yamamoto

Atsuhiro Sumiya

Tadashi Hattori

Masahiro Tomita

Akira Fujii

Takumi Kataoka

Keiji Aoki

Kaoru Kuzuoka

Susumu Sato

Masanori Yamada

Itsuhei Ogata

Yasushi Sawada

Shigeyuki Akita

Masao Kodera

Mitsuru Asano

Hiroyuki Yoshida

Yoichi Kotanshi

Hiroshi Matsuoka

Noriaki Kihara

Toshihiko Igashira

Yasuyuki Sakakibara

Yoshiaki Fukushima

Masaya Nakamura

Makoto Shirai

Daisuke Makino

Akio Iwase

Masatoshi Ikeda

Hirokatsu Mukai

Tatsuhiko Nonoyama

Yasuyuki Satou

Tomio Kawakami

Hiroo Imamura

Yasunori Suzuki

Takumi Ushikubo

Kumi Sawaguchi

Yoshinori Nakayama

Michihiro Wakimoto

Youta Iwamoto

Kenichi Hanaki

Naochika Nunogaki

Hiroshi Matuoka

Ryoji Kai

Hiroyuki Satou

Hirosi Matuoka

Atsuhiro Sumita

Methods of manufacturing a ceramic sheet and a gas sensing element are disclosed. At least ceramic powder, a binder and a plasticizer are blended and mixed in slurry. The slurry is formed into unfired green sheets, on which paste is printed. Each of the unfired green sheets has porosity greater than 5%. In the manufacturing methods, the unfired green sheets are pressurized with a pressure of 10 MPa at a temperature above 60&#xb0; C., after which the paste is printed on surfaces of the unfired green sheets. In the method of manufacturing the gas sensing element, a shielding layer, a porous diffusion resistance layer and the unfired green sheets for a sensing layer, a reference gas airspace forming layer and a heating layer are stacked to form a stacked ceramic body, whish is fired to obtain the gas sensing element.

Method of manufacturing ceramic sheet and method of manufacturing gas sensing element

A stacked piezoelectric element obtained by alternately stacking a piezoelectric ceramic layer and an electrode layer, wherein said electrode layer mainly comprises an electrically conducting base metal electrode material, and the region held between the electrode layer positioned at the top of each ceramic layer and the electrode layer positioned at the bottom of each ceramic layer contains a material having no piezoelectricity, in which a constituent element of said material having no piezoelectricity is uniformly dispersed so as not to have local distribution of a distributed strength exceeding 2 times the distributed strength which is distributed in a largest number of places and is not 0.

Stacked piezoelectric element and production method thereof

A method of producing a laminated dielectric element of high quality, free of delamination. A method of producing a laminated dielectric elementby alternately laminating dielectric ceramic layersand base metal electrode layerscomprising the steps of printing electrodes by applying a paste material for the base metal electrodes onto the surfaces of at least one side of the ceramic green sheets, laminating and press-adhering the ceramic green sheets to fabricate a laminate thereof, dewaxing the laminate, reducing the electrodes to form base metal electrode layers by heating the laminate while flowing an atmospheric gas and by reducing the paste material for the base metal electrodes, and sintering the laminate. In the step of reducing the electrodes, the paste material for the base metal electrodes is so reduced that the amount of the base metal oxide remaining in the base metal electrode layers is not larger than 20% by weight and that the amount of lead liberated from the ceramic material is not larger than 30 atomic % within 5000 &#x212b; from the surfaces of the base metal electrode layers.

Method for fabricating laminate-type dielectric element

This invention provides a method of producing a laminate type dielectric device free from peeling of an electrode layer and a ceramic layer and from voids in both electrode layer and ceramic layer, and an electrode paste material. The invention relates also to an electrode paste material for constituting electrode layers of a laminate type dielectric device produced by at least the steps of alternately laminating ceramic layerscontaining a lead element as a constituent component and electrode layers, and degreasing and baking the laminate, wherein the electrode paste material contains CuO as a principal component of a starting material of an electrically conductive material, a solvent, a binder, and a cooperative material consisting of at least one kind of the main components constituting the ceramic layer

Production method for laminate type dielectric device and electrode paste material

This invention provides a stacked ceramic body that prevents reaction between components of dielectric layers and components of electrode layers of an unsintered stacked body during sintering and in which both components do not easily form a liquid phase, and a production method of such a stacked ceramic body. A print portionis formed on a green sheetcontaining lead by use of an electrode paste consisting of copper oxide as its main component. A desired number of print sheetsare stacked to give an unsintered stacked body. Degreasing is conducted in an atmosphere to degrease organic components. The print portionis subjected to reducing treatment in a reducing atmosphere containing hydrogen and is converted to a print portioncontaining copper as its main component. The unsintered stacked bodyis sintered in a reducing atmosphere. Dielectric layers containing lead and electrode layers for applying a voltage to the dielectric layers are alternately stacked, and an oxidation portion containing copper is formed in the proximity of a surface of the electrode layer. A thickness of the oxidation portion in a stacking direction is 0.5 to 2 &#x3bc;m and a copper content in the oxidation portion is 1 to 30 wt %.

Stacked ceramic body and production method thereof

The thermistor portion of a thermistor device consists of a mixed sintered body of aY(CrMn)O.bAlOmade of the perovskite-type compound Y(CrMn)Oand AlO, or a mixed sintered body of aY(CrMn)O.b(AlO+YO) made of Y(CrMn)O, AlOand YO. The mole fractions a and b have the relationships 0.05&#x2266;a&#x3c;1.0, 0&#x3c;b&#x2266;0.95 and a+b=1. This is required to obtain a thermistor device that has stable characteristics and exhibits a small change in its resistance value, even in a heat history from room temperature to 1000&#xb0; C. or the like, and also has a resistance value of 50&#x3a9; to 100 k&#x3a9; in the temperature range from room temperature to 1000&#xb0; C. The precursor compounds triethoxy yttrium, diethoxy manganese and tris (2,4-pentadiono) chromium are mixed in a mixed solvent of ethanol and isopropyl alcohol, and refluxing is performed to obtain a composite metal alkoxide solution. Then the metal salt precipitating agent of deionized water is added, the mixture is stirred and mixed and refluxing is performed to obtain a gelatinous precipitate of metallic salts containing Y, Mn and Cr. This precipitate is separated by filtration, dried and calcined to obtain powdered raw material with a composition of 38Y(CrMn)O.62YO, the same as that of a thermistor device. Thereafter, this powdered raw material is molded and sintered to obtain the thermistor device as a sintered body. Thereby, the dispersion of the resistance value of the thermistor can be reduced. An anti-reducing coating made of an anti-reducing material such as YO, AlO, YAlO, 3AlO.SiO, YSiOor the like is formed on the surface of a thermistor portion consisting of a mixed sintered body of Y(CrMn)O.YO(or Y(CrMn)O.AlO) or the like to form a thermistor device with a pair of lead wires attached. Thereby, the thermistor device exhibits resistance value stability even when subjected to a reducing atmosphere.

Thermistor device, thermistor device manufacturing method and temperature sensor

This invention provides a method for producing a stacked ceramic body that does not require strict control of an oxygen partial pressure in a sintering gas. To produce a stacked ceramic body by alternately stacking dielectric layer and electrode layers, an unsintered stacked bodyis prepared by alternately stacking unsintered dielectric layers containing a PZT type dielectric material and unsintered electrode layers containing an electrode material, and is sintered in a sintering gas to which a dielectric layer anti-reducing agentand an electrode layer anti-oxidantare introduced. Alternatively, sintering is conducted in a gas containing only the dielectric layer anti-reducing agentor in a gas containing only the electrode layer anti-oxidant

Method for producing stacked ceramic body

A PZT dielectric ceramic material is sintered at a desired low temperature to prevent deterioration of the performance of the base material. An auxiliary oxide is used that is made by adding the oxide of at least one of tungsten and molybdenum to lead oxide in the following proportions:PbO+(WO+MoO)where x+y+z=1, 0.005&#x3c;y+z&#x3c;0.4 and y, z&#x2267;0. 0.5 mol % to 20 mol % of this auxiliary oxide is added to a mixture of a stock material of dielectric ceramic material or its calcination having a composition of ABOtype dielectric ceramic material where 0.9 molar ratio or more lead is included in site A assuming the proportion of site B is 1, and the material is mixed, formed and sintered. The content of tungsten and molybdenum combined is less than 0.098 mole in proportion to 1 mole of lead and the density of the dielectric ceramic material after sintering is 7.5 g/cmlarger. The auxiliary oxide is dispersed in the calcined powder to form a liquid phase at a desired temperature, to accelerate the sintering, thus making it possible to sinter at a lower temperature.

Dielectric ceramic material and method for producing the same

A method of manufacturing large-sized laminated dielectrics of high quality which permit adjustment of the atmosphere during sintering process to be accomplished easily, and which can eliminate the problems such as expansion due to reaction with the atmosphere gas. When a laminated body , consisting of oxide dielectric layers and inner electrode layers having a base metal such as Cu as a main component, is sintered in a reducing atmosphere, a mixed gas having CO gas as a main component and containing optional amount of CO gas and O gas is used. By using the equilibrium system of CO &rlarr;2CO&plus;(1/2)O and adjusting the amounts of CO gas and O gas, oxygen partial pressure in the atmosphere gas can be easily and stably adjusted and fluctuation and variation in the atmosphere can be suppressed.

Method for manufacturing laminated dielectrics

The thermistor element of the present invention is composed of a mixed sintered body aM M O bY O of a composition M M O (wherein M is Y, and M is at least one element selected from the elements such as Cr, Mn, Ti, etc.) as a perovskite compound and Y O , wherein molar fractions a and b satisfy the relations 0.05&lE;a<1.0, 0<b&lE;0.95 and a&plus;b&equals;1. Another wide-range type thermistor element of the present invention is composed of a perovskite compound M (M M )O , wherein M is at least one element selected from the elements of the groups II and IIIA excluding La in the Periodic Table, and each of M and M is at least one element selected from the elements of the groups IIB, IIIB, IVA, VA, VIA, VIIA and VIII. a and b satisfy the relations a&plus;b&equals;1 and 0<b<0.1, where a is a molar fraction of M and b is a molar fraction of M in M (M M )O .

Wide-range type thermistor element and method of producing the same

An integrally fired, laminated electromechanical transducing element, fabricated using an inexpensive electrode material and having the electrode characteristic at least equivalent to that of the Ag&mdash;Pd electrode, is disclosed. Especially, in the integrally fired, laminated electromechanical transducing element according to the invention, (A) the rigidity of the internal electrode layers is low and the internal stress generated at the time of expansion or contraction of the ceramic layers is small, (B) the antimigration characteristic is superior, (C) the charge loss is small, the heat conductivity is high and the heat radiation characteristic is superior, and/or (D) the bonding strength between the ceramic layers and the electrode layers is high. The integrally fired, laminated electromechanical transducing element ( ) according to the invention comprises, for example, an integrally fired laminate member fabricated by integrally firing a plurality of the ceramic layers ( ) of piezoelectric ceramic or electrostrictive ceramic and the internal electrode layers ( ) interposed between the ceramic layers ( ). The main component of the internal electrode layers ( ) is a base metal having a rigidity of not more than 160 GPa.

Integrally fired, laminated electromechanical transducing element

A piezoelectric material exhibiting a high Curie point and a high displacement at a low drive voltage is provided. The piezoelectric material contains as a main component a composite oxide and is expressed by the general formula &lsqb;Pb&lcub;1&minus;x &minus;x &minus;&agr;(x &minus;x )&rcub;, A x , A x &rsqb; &lcub;(Tiy, Zrz) (1&minus;&bgr;(x &minus;x )&minus;&ggr;), (Y , Nb )&ggr;&rcub;O , where y&plus;z&equals;1, 1.15<z/y<1.30 and 0<&ggr;<0.1; and A , A , x , x satisfy any of the conditions (i) A is at least selected one of Ce and La, A is K, 0.02&lE;x <0.08, 0&lE;x &lE;0.05 (0.02&lE;x &plus;x &lE;0.1, x &lE;x ) and &agr;&equals;0, &bgr;&equals;0.25 or &agr;&equals;0.5, &bgr;&equals;0, and (ii) A is Sr, A is Ba, 0.03&lE;x &lE;0.05, 0.03&lE;x &lE;0.05 (&verbar;x &minus;x &verbar;&lE;0.01), and &agr;&equals;0, &bgr;&equals;0.

Piezoelectric material and manufacturing method thereof

This invention provides a piezoelectric laminate body that limits, to a minimum, the difference of the quantity of displacement occurring in the boundary between an electrode center portion of a unit laminate body and its alternate electrode portions upon the application of an electric field, by improving a laminate structure of alternate electrode structure type unit laminate bodies. Each piezoelectric device sheet of the unit laminate bodies constituting this piezoelectric laminate body integrally includes a device sheet portion and each lug portion and is made of a piezoelectric ceramic material. An electrode layer is so formed as to extend to the surface of the device sheet portion and the surface of the lug portion Among the laminate sheets the electrode layer of a lower laminate sheet overlaps with the back of an upper laminate sheet Each unit laminate body is laminated serially in such a fashion that the positions of the uppermost unit laminate body to the lowermost unit laminate body are deviated at 90 degrees in a direction orthogonal to the laminating direction (FIG. 3).

Piezoelectric laminate body

A ceramic piezoelectric transformer is provided which includes a compression mechanism. The compression mechanism is made up of, for example, a bolt and a nut which add a given compressive stress to a transformer body in a lengthwise direction thereof for absorbing a tensile stress arising from oscillations of the transformer body during operation, thereby allowing output energy from the transformer to be increased. In a modified form, a weight block is mounted on an end of the transformer body to increase the range of the output energy.

Piezoelectric transformer having increased voltage output

The thermistor portion of a thermistor device consists of a mixed sintered body of aY(Cr,Mn,)O,.bAl,O,made of the perovskite-type compound Y(Cr,Mn,)O,and Al,O,, or a mixed sintered body of aY(Cr,Mn,)O,.b(Al,O,&plus;Y,O,) made of Y(Cr,Mn,)O,, Al,O,and Y,O,. The mole fractions a and b have the relationships 0.05&lE;a>1.0, 0<b&lE;0.95 and a&plus;b&equals;1. This is required to obtain a thermistor device that has stable characteristics and exhibits a small change in its resistance value, even in a heat history from room temperature to 1000&deg; C. or the like, and also has a resistance value of 50&OHgr; to 100 k&OHgr; in the temperature range from room temperature to 1000&deg; C.

Thermistor device thermistor device manufacturing method and temperature sensor

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Okazaki, Japan

Eturo Yasuda