Patents by Inventor Atsushi Kishimoto
Atsushi Kishimoto has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20100001828Abstract: A multilayer positive temperature coefficient thermistor includes a ceramic body having semiconductor ceramic layers and internal electrodes, the semiconductor ceramic layers being mainly composed of BaTiO3 and containing semiconductor-forming agents, the semiconductor ceramic layers and the internal electrodes being alternately stacked, and the outermost layers of the ceramic body being formed of the semiconductor ceramic layers. The outermost layers serve as protective layers. The semiconductor ceramic layers arranged between the internal electrodes 4a and 4d serve as effective layers. The protective layers contain a semiconductor-forming agent having a larger ionic radius than that of a semiconductor-forming agent contained in the effective layers. The protective layers have a lower porosity than that of the effective layers. Preferably, glass films are formed in pores in surfaces of the protective layers, and the protective layers have a porosity of 10% or less.Type: ApplicationFiled: September 18, 2009Publication date: January 7, 2010Inventors: Kenjirou Mihara, Atsushi Kishimoto
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Publication number: 20080204187Abstract: A multilayer positive temperature coefficient thermistor that has semiconductor ceramic layers containing a BaTiO3-based ceramic material as a primary component, and at least one element selected from the group consisting of Eu, Gd, Tb, Dy, Y, Ho, Er, and Tm as a semiconductor dopant in the range of 0.1 to 0.5 molar parts with respect to 100 molar parts of Ti. The ratio of the Ba site to the Ti site is in the range of 0.998 to 1.006. Accordingly, even when the semiconductor ceramic layers have a low actual-measured sintered density in the range of 65% to 90 % of a theoretical sintered density, a multilayer positive temperature coefficient thermistor having a sufficiently high rate of resistance change and a high rising coefficient of resistance at the Curie temperature or more can be realized.Type: ApplicationFiled: March 18, 2008Publication date: August 28, 2008Applicant: Murata Manufacturing Co., Ltd.Inventors: Atsushi Kishimoto, Kenjirou Mihara, Hideaki Niimi
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Publication number: 20080204186Abstract: A multilayer positive temperature coefficient thermistor that has a BaTiO3-based ceramic material contained as a primary component in semiconductor ceramic layers, the ratio of the Ba site to the Ti site is in the range of 0.998 to 1.006, and at least one element selected from the group consisting of La, Ce, Pr, Nd, and Pm is contained as a semiconductor dopant. In this multilayer positive temperature coefficient thermistor, a thickness d of internal electrodes layer and a thickness D of the semiconductor ceramic layers satisfy d?0.6 ?m and d/D<0.2. Accordingly, even when the semiconductor ceramic layers have a low sintered density such that an actual-measured sintered density is 65% to 90% of a theoretical sintered density, a multilayer positive temperature coefficient thermistor having a low rate of temporal change in room-temperature resistance can be obtained without performing any complicated processes, such as a heat treatment. When the content of the semiconductor dopant is 0.1 to 0.Type: ApplicationFiled: March 17, 2008Publication date: August 28, 2008Applicant: Murata Manufacturing Co., Ltd.Inventors: Kenjirou Mihara, Atsushi Kishimoto, Hideaki Niimi
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Patent number: 7295421Abstract: A multilayer ceramic electronic component includes a skittered laminated body including internal electrodes that have a strength that is greater than that of ceramic layers provided therein. End portions of the internal electrodes protrude from end surfaces of the laminated body and are deformed so as to extend along the end surfaces by a barrel polishing process using balls. When external electrodes are formed on the end surfaces of the laminated body, a large contact area with the internal electrodes can be obtained. Therefore, a reliability of the electrical connection between the electrodes is definitely secured.Type: GrantFiled: February 18, 2004Date of Patent: November 13, 2007Assignee: Murata Manufacturing Co., Ltd.Inventors: Kenjiro Mihara, Atsushi Kishimoto, Hideaki Niimi
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Publication number: 20060145401Abstract: A multilayer ceramic electronic component includes a sintered laminated body including internal electrodes that have a strength that is greater than that of ceramic layers provided therein. End portions of the internal electrodes protrude from end surfaces of the laminated body and are deformed so as to extend along the end surfaces by a barrel polishing process using balls. When external electrodes are formed on the end surfaces of the laminated body, a large contact area with the internal electrodes can be obtained. Therefore, a reliability of the electrical connection between the electrodes is definitely secured.Type: ApplicationFiled: February 18, 2004Publication date: July 6, 2006Inventors: Kenjiro Mihara, Atsushi Kishimoto, Hideyaki Niimi
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Patent number: 6984543Abstract: A method of producing a laminated PTC thermistor involves alternately laminating electroconductive pastes to form internal electrodes and ceramic green sheets to form semiconductor ceramic layers with a positive resistance-temperature characteristic to form a laminate, firing the laminate to form a ceramic piece, and forming external electrodes on both of the end-faces of the ceramic piece, and heat-treating the ceramic piece having the external electrodes formed thereon at a temperature between about 60° C. and 200° C.Type: GrantFiled: August 13, 2003Date of Patent: January 10, 2006Assignee: Murata Manufacturing Co., Ltd.Inventors: Kenjirou Mihara, Atsushi Kishimoto, Hideaki Niimi
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Patent number: 6911893Abstract: A ceramic electronic component includes a component body having semiconductive ceramic layers and internal electrodes. The semiconductive ceramic layers and the internal electrodes are alternately laminated. The semiconductive ceramic layers have a relative density of about 90% or less and contain no sintering additives. The component body is provided with an external electrode on each side thereof. The ceramic electronic component has a low resistance and a high withstand voltage.Type: GrantFiled: December 18, 2001Date of Patent: June 28, 2005Assignee: Murata Manufacturing Co., Ltd.Inventors: Masahiro Kodama, Atsushi Kishimoto, Mitsutoshi Kawamoto, Hideaki Niimi, Akira Ando
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Patent number: 6791163Abstract: A chip electronic component including a ceramic element and terminal electrodes with metal coating thereon formed on the surface of the ceramic element. A glass layer is formed on a part of the surface of the ceramic element where the terminal electrodes are not formed. A glass material for the glass layer contains at least two species of alkali metal elements selected from Li, Na and K, and the total amount of the alkali metal elements is greater than or equal to 20 atomic percent of the total amount of elements except oxygen contained in the glass material.Type: GrantFiled: September 9, 2003Date of Patent: September 14, 2004Assignee: Murata Manufacturing Co. Ltd.Inventors: Atsushi Kishimoto, Hideaki Niimi, Akira Ando
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Publication number: 20040140595Abstract: A multilayer thermistor with a positive temperature coefficient is manufactured by step 41 of forming a green laminate having thermistor green layers and internal electrode layers, step 42 of heat-treating this laminate at a temperature in the range of from 80 to less than 300° C., step 43 of performing dry-barrel polishing for the heat-treated green laminate, step 44 of forming external electrode films on respective end surfaces of this laminate, and step 45 of firing this laminate together with the individual electrode films. According to this method, a highly reliable multilayer thermistor with a positive temperature coefficient can be stably manufactured.Type: ApplicationFiled: November 6, 2003Publication date: July 22, 2004Inventors: Kenjiro Mihara, Atsushi Kishimoto, Hideaki Niimi
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Publication number: 20040048052Abstract: A chip electronic component including a ceramic element and terminal electrodes with metal coating thereon formed on the surface of the ceramic element. A glass layer is formed on a part of the surface of the ceramic element where the terminal electrodes are not formed. A glass material for the glass layer contains at least two species of alkali metal elements selected from Li, Na and K, and the total amount of the alkali metal elements is greater than or equal to 20 atomic percent of the total amount of elements except oxygen contained in the glass material.Type: ApplicationFiled: September 9, 2003Publication date: March 11, 2004Inventors: Atsushi Kishimoto, Hideaki Niimi, Akira Ando
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Publication number: 20040033629Abstract: A method of producing a laminated PTC thermistor involves alternately laminating electroconductive pastes to form internal electrodes and ceramic green sheets to form semiconductor ceramic layers with a positive resistance-temperature characteristic to form a laminate, firing the laminate to form a ceramic piece, and forming external electrodes on both of the end-faces of the ceramic piece, and heat-treating the ceramic piece having the external electrodes formed thereon at a temperature between about 60° C. and 200° C.Type: ApplicationFiled: August 13, 2003Publication date: February 19, 2004Inventors: Kenjirou Mihara, Atsushi Kishimoto, Hideaki Niimi
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Patent number: 6545857Abstract: A chip-type electronic component is provided in which generation of cracks in a glass coating layer and degradation of the insulating resistance in the ceramic body is unlikely to occur. In addition, a manufacturing method therefor is also provided. In the glass coating layer described above, the ratio of the alkali metal content to the silicon content is gradually increased from the vicinity of the glass coating layer to the inside thereof. The component is formed by forming a glass coating layer on surfaces of the component, in which the ratio of the alkali metal to the silicon in the glass coating layer is 0.3 or more; and a subsequent step of dipping the component provided with the glass coating layer in an acidic aqueous solution.Type: GrantFiled: July 20, 2001Date of Patent: April 8, 2003Assignee: Murata Manufacturing Co. Ltd.Inventors: Atsushi Kishimoto, Masahiro Kodama, Hideaki Nimi
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Publication number: 20020130318Abstract: A ceramic electronic component includes a component body having semiconductive ceramic layers and internal electrodes. The semiconductive ceramic layers and the internal electrodes are alternately laminated. The semiconductive ceramic layers have a relative density of about 90% or less and contain no sintering additives. The component body is provided with an external electrode on each side thereof. The ceramic electronic component has a low resistance and a high withstand voltage.Type: ApplicationFiled: December 18, 2001Publication date: September 19, 2002Applicant: Murata Manufacturing Co., Ltd.Inventors: Masahiro Kodama, Atsushi Kishimoto, Mitsutoshi Kawamoto, Hideaki Niimi, Akira Ando
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Publication number: 20020105022Abstract: A monolithic semiconducting electronic component includes barium titanate-based semiconducting ceramic layers and internal electrode layers, which are alternately laminated, and external electrodes arranged to be electrically connected to the internal electrode layers. The ratio S/I of the thickness S of each of the semiconducting ceramic layers to the thickness I of each of the internal electrode layers is about 10 to about 50. Preferably, the internal electrode layers are composed of a nickel-based metal.Type: ApplicationFiled: December 11, 2000Publication date: August 8, 2002Applicant: Murata Manufacturing Co., LtdInventors: Mitsutoshi Kawamoto, Hideaki Niimi, Masahiro Kodama, Atsushi Kishimoto
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Publication number: 20020027764Abstract: A chip-type electronic component is provided in which generation of cracks in a glass coating layer and degradation of the insulating resistance in the ceramic body is unlikely to occur. In addition, a manufacturing method therefor is also provided. In the glass coating layer described above, the ratio of the alkali metal content to the silicon content is gradually increased from the vicinity of the glass coating layer to the inside thereof. The component is formed by forming a glass coating layer on surfaces of the component, in which the ratio of the alkali metal to the silicon in the glass coating layer is 0.3 or more; and a subsequent step of dipping the component provided with the glass coating layer in an acidic aqueous solution.Type: ApplicationFiled: July 20, 2001Publication date: March 7, 2002Applicant: Murata Manufacturing Co., Ltd.Inventors: Atsushi Kishimoto, Masahiro Kodama, Hideaki Nimi