Denso Corporation

Nippondenso Co., Ltd.

Other

Nippon Soken, Inc.

Kabushiki Kaisha Toyota Chuo Kenkyusho

Kaoru Kuzuoka

Itsuhei Ogata

Eturo Yasuda

Masanori Yamada

Daisuke Makino

Kazuhiro Inoguchi

Tsunenobu Hori

Atsushi Kurano

Takumi Kataoka

Chiaki Ogawa

Motoki Satou

Masamichi Shibata

Kozo Takamura

Katsunori Yamada

Yuusuke Toudou

Takao Kobayashi

Muneo Yorinaga

Sotoo Takahashi

Junichi Nagai

Matuo Fukaya

Susumu Shibayama

A temperature sensorincludes: a thermosensitive elementcomposed of a low-thermal expansion ceramics having a coefficient of linear expansion of 3&#xd7;10/&#xb0; C. to 5&#xd7;10/&#xb0; C. and of which electrical characteristics change depending on temperature; a pair of electrode filmsprovided on the surfaces of the thermosensitive element; and a pair of lead wires having a coefficient of linear expansion of 15&#xd7;10/&#xb0; C. or less and bonded to the electrode films. When the coefficients of linear expansion of the thermosensitive element, the electrode film, and the lead wireare respectively T(/&#xb0; C.), T(/&#xb0; C.), and T(/&#xb0; C.), the temperature sensorsatisfies a relationship T&#x2266;T&#x2266;T.

Temperature sensor including thermosensitive element

A temperature sensing element includes a thermistor composed of Si-base ceramics and a pair of metal electrodes bonded onto the surfaces of the thermistor. The metal electrodes contain Cr and a metal element &#x3b1; having a Si diffusion coefficient higher than that of Cr. A diffusion layer is formed in a bonding interface between the thermistor and each metal electrode, the diffusion layer including a silicide of the metal element &#x3b1; in a crystal grain boundary of the Si-base ceramics. A temperature sensor including the diffusion layers is provided. Owing to the diffusion layers, the temperature sensor ensures heat resistance and bonding reliability and enables temperature detection with high accuracy in a temperature range, in particular, of from &#x2212;50&#xb0; C. to 1050&#xb0; C.

Temperature sensor element, method for manufacturing same, and temperature sensor

In a temperature sensor having a temperature sensitive element, a sheath pin connected to the temperature sensitive element, and a cover case. The cover case, filled with a filler, accommodates the temperature sensitive element and the sheath pin. A hardening temperature of the filler is not less than an actual usage environment of the temperature sensor. Another temperature sensor has a temperature sensitive element exposed at a high temperature of not less than 750&#xb0; C., a thermistor element, a sheath pin, an anti-vibration filler, and a metal cover case fixed to an end part of the sheath pin. The metal cover case accommodates the sheath pin and the thermistor element. The filler is made of a porous insulation material having a pore ratio within a range of 30 to 70% and filled around the thermistor element in the metal cover case.

Temperature sensor and method of producing the temperature sensor

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

A highly accurate reduction resistant thermistor exhibiting stable resistance characteristics even under conditions where the inside of a metal case of a temperature sensor becomes a reducing atmosphere, wherein when producing the thermistor comprised of a mixed sintered body (M1 M2)O.AO, the mean particle size of the thermistor material containing the metal oxide, obtained by heat treating, mixing, and pulverizing the starting materials, is made smaller than 1.0 &#x3bc;m and the sintered particle size of the mixed sintered body, obtained by shaping and firing this thermistor material, is made 3 &#x3bc;m to 20 &#x3bc;m so as to reduce the grain boundaries where migration of oxygen occurs, suppress migration of oxygen, and improve the reduction resistance.

Reduction resistant thermistor, method of production thereof, and temperature sensor

Thermistor elements composed mainly of a metal oxide sintered body are prepared by mixing a metal oxide precursor in a liquid phase to prepare a solution or slurry of the precursor. The precursor solution or slurry is sprayed to form droplet particles which are heat treated to form a thermistor raw material powder which powder is then molded and sintered into a shape to provide a metal oxide sintered body.

Method of producing thermistor element and production apparatus for production apparatus for producing raw materials for thermistor element

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

This invention provides a reducing-atmosphere-resistant thermistor element, the resistance of which does not greatly change even when the element is exposed to a reducing atmosphere, and which has high accuracy and exhibits excellent resistance value stability. The thermistor element has a construction in which an oxygen occlusion-release composition, having oxygen occlusion-release characteristics, such as CeO is dispersed in a composition containing a mixed sintered body (M1 M2)O .AO as a principal component. The oxygen occlusion-release composition emits absorbed oxygen in a reducing atmosphere and suppresses migration of oxygen from the composition constituting the element. Therefore, the resistance value does not greatly change even when the element is exposed to a reducing atmosphere, and the element can accurately detect the temperature for a long time. The present invention can thus provide a temperature sensor having high reliability.

Reducing-atmosphere-resistant thermistor element, production method thereof and temperature sensor

A temperature sensor has a sensing element ( ) consisting of a thermistor ( ) and leads ( ) and a sheath pin ( ) containing core wires ( ), to accurately detect temperature. A method of manufacturing such a temperature sensor includes the steps of connecting the leads to the core wires, arranging an insulator ( ) around the sensing element, filling the insulator with an inorganic adhesive ( ) to fix the sensing element in the insulator, arranging a metal cover ( ) around the insulator, and joining an end of the metal cover to an end of the sheath pin.

Temperature sensor and method of manufacturing same

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

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,.

The present invention relates a method for manufacturing high-temperature thermistor materials having stable thermistor properties and to a high-temperature thermistor. According to this method the thermistor material is obtained by mixing powders of (Mn.Cr) O.sub.4 spinel powder and Y.sub.2 O.sub.3 powder and firing the mixed powder at a temperature in a range of 1400.degree. to 1700.degree. C., so as to cause the components of the mixture to react with each other, thereby generating (Mn.sub.x.Cr.sub.y) O.sub.4 spinel and Y(Cr.Mn) O.sub.3 perovskite.

Method for manufacturing thermistor materials and thermistors

A thermistor type temperature sensor includes a mounting sheet made of insulating ceramic; a plurality of thermistor elements disposed on the mounting sheet; a detecting device, disposed on the mounting sheet, for electrically conducting with the thermistor elements and detecting changes in the resistance value of the thermistor elements; and a cover sheet for hermetically sealing the thermistor elements and the detecting device by thermocompression-bonding with the mounting sheet.

Thermistor type temperature sensor

A thermistor type temperature sensor having a substrate made from an electrically insulating ceramic plate. A thin or thick film detecting resistor is printed on the substratum. A thick or thin film pull-up resistor may also be printed on the substratum, and trimming of the resistors is possible. The ratio of B-constant values for the detecting resistor and the pull-up resistor may be selected so that it is locate between 0.4 to 0.9 or 1.1 to 1.5. The detecting resistor may be constructed from thermistor sections of the same composition and the sections may be connected in parallel or in series. The thermistor sensor can be connected to the pipe through which a gas passes. When the sensor is connected to the pipe, the angle of the measuring plane may be adjusted, so that a precise measurement can be obtained.

Thermistor having temperature detecting sections of substantially the

According to the present invention, a temperature sensor for high temperature comprises a ceramic plate on the surface of which is provided a thermistor layer, electrodes connected to the thermistor layer, and the thermistor layer containing ZnCr.sub.2 O.sub.4. It is preferable that the thermistor layer contain a resistance conditioning agent composed of either ZnO or Cr.sub.2 O.sub.3 or both, and that it contains at least one of the sintering auxiliaries selected from the group: SiO.sub.2, CaO, MgO, CaCO.sub.3, kaolin, and talc. Accordingly, it is possible to obtain stable resistance-temperature characteristics at high temperature as well as superior heat resistance.

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Toyota, Japan

Kaoru Kuzuoka