Patents by Inventor Kazumichi HIROI
Kazumichi HIROI 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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Patent number: 11756736Abstract: A manufacturing method of ceramic powder includes mixing a barium carbonate having a specific surface are of 15 m2/g or more, a titanium dioxide having a specific surface area of 20 m2/g or more, a first compound of a donor element having a larger valence than Ti, and a second compound of an acceptor element having a smaller valence than Ti and having a larger ion radium than Ti and the donor element, and synthesizing barium titanate powder by calcining the barium carbonate, the titanium dioxide, the first compound and the second compound until a specific surface area of the barium titanate powder becomes 4 m2/g or more and 25 m2/g or less.Type: GrantFiled: October 14, 2021Date of Patent: September 12, 2023Assignee: TAIYO YUDEN CO., LTD.Inventors: Chie Kawamura, Kazumichi Hiroi, Osamu Hattori
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Publication number: 20230282423Abstract: A multilayer ceramic electronic component includes a ceramic body, which includes an electrode-stacking portion in which internal electrodes are stacked, and cover portions facing each other in a first axis direction across the electrode-stacking portion, and external electrodes each including a covering portion that covers the ceramic body from a second axis direction, and an extending portion that extends over the cover portions along the second axis direction. The ceramic body includes crystal grains of ceramic and segregated small grains located between the crystal grains. In a cross section of an end section located between the extending portion of the cover portion and the electrode-stacking portion, the number of the segregated small grains having a grain size of 0.5% or greater and 10% or less of an average grain size of the crystal grains is 40% or greater and 95% or less of the number of the crystal grains.Type: ApplicationFiled: March 1, 2023Publication date: September 7, 2023Applicant: TAIYO YUDEN CO., LTD.Inventors: Norihiro ARAI, Kazumichi HIROI, Hirokazu SHIMIZU
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Publication number: 20230081197Abstract: A ceramic electronic device includes a multilayer structure in which a plurality of dielectric layers and a plurality of internal electrode layers are alternately stacked. Each of the plurality of dielectric layers includes ceramic grains of a main component thereof expressed by (Ba1?x?yCaxSry)(Ti1?zZrz)O3 (0<x?0.2, 0?y?0.1, 0?z?0.1). D3<D1<D2 is satisfied when an average grain diameter of the ceramic grains of the main component of the plurality of dielectric layers in a section in which each two internal electrode layers is D1, an average grain diameter of the ceramic grains of the main component of first dielectric layers which are located at different height positions from the internal electrode layers is D2, an average grain diameter of the ceramic grains of the main component of second dielectric layers which are located at same height positions of the internal electrode layers is D3.Type: ApplicationFiled: August 8, 2022Publication date: March 16, 2023Applicant: TAIYO YUDEN CO., LTD.Inventors: Yasuyuki INOMATA, Kazumichi HIROI
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Publication number: 20220037088Abstract: A manufacturing method of ceramic powder includes mixing a barium carbonate having a specific surface are of 15 m2/g or more, a titanium dioxide having a specific surface area of 20 m2/g or more, a first compound of a donor element having a larger valence than Ti, and a second compound of an acceptor element having a smaller valence than Ti and having a larger ion radium than Ti and the donor element, and synthesizing barium titanate powder by calcining the barium carbonate, the titanium dioxide, the first compound and the second compound until a specific surface area of the barium titanate powder becomes 4 m2/g or more and 25 m2/g or less.Type: ApplicationFiled: October 14, 2021Publication date: February 3, 2022Inventors: Chie KAWAMURA, Kazumichi HIROI, Osamu HATTORI
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Patent number: 11177073Abstract: A manufacturing method of ceramic powder includes: synthesizing barium titanate powder from barium carbonate, titanium dioxide, manganese carbonate, and one of ammonium molybdate and tungsten oxide, wherein: a solid solution amount of the donor element is 0.05 mol or more and 0.3 mol or less; a solid solution amount of the accepter element with respect to the barium titanate is 0.02 mol or more and 0.2 mol or less on a presumption that the amount of the barium titanate is 100 mol and the acceptor element is converted into an oxide; and relationships y??0.0003x+1.0106, y??0.0002x+1.0114, 4?x?25 and y?1.0099 are satisfied when a specific surface area of the ceramic powder is “x” and an axial ratio c/a of the ceramic powder is “y”.Type: GrantFiled: May 22, 2020Date of Patent: November 16, 2021Assignee: TAIYO YUDEN CO., LTD.Inventors: Chie Kawamura, Kazumichi Hiroi, Osamu Hattori
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Publication number: 20200286684Abstract: A manufacturing method of ceramic powder includes: synthesizing barium titanate powder from barium carbonate, titanium dioxide, manganese carbonate, and one of ammonium molybdate and tungsten oxide, wherein: a solid solution amount of the donor element is 0.05 mol or more and 0.3 mol or less; a solid solution amount of the accepter element with respect to the barium titanate is 0.02 mol or more and 0.2 mol or less on a presumption that the amount of the barium titanate is 100 mol and the acceptor element is converted into an oxide; and relationships y??0.0003x+1.0106, y??0.0002x+1.0114, 4?x?25 and y?1.0099 are satisfied when a specific surface area of the ceramic powder is “x” and an axial ratio c/a of the ceramic powder is “y”.Type: ApplicationFiled: May 22, 2020Publication date: September 10, 2020Inventors: Chie KAWAMURA, Kazumichi HIROI, Osamu HATTORI
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Publication number: 20190043668Abstract: Ceramic powder includes: barium titanate as a main component, wherein: a donor element having a larger valence than Ti is solid-solved in the barium titanate; an acceptor element having a smaller valence than Ti and larger ion radius than Ti and the donor element is solid-solved in the barium titanate, a solid solution amount of the donor element with respect to the barium titanate is 0.05 mol or more and 0.3 mol or less; a solid solution amount of the accepter element with respect to the barium titanate is 0.02 mol or more and 0.2 mol or less; and relationships y??0.0003x+1.0106, y??0.0002x+1.0114, 4?x?25 and y?1.0099 are satisfied when a specific surface area of the ceramic powder is “x” and an axial ratio c/a of the ceramic powder is “y”.Type: ApplicationFiled: October 9, 2018Publication date: February 7, 2019Inventors: Chie KAWAMURA, Kazumichi HIROI, Osamu HATTORI
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Patent number: 9919970Abstract: Dielectric layers are prepared using a dielectric material that contains a ceramic powder having Ba, Ti, and additive element X which is solid-solubilized and is at least one element selected from the group consisting of Mo, Ta, Nb, and W, wherein the standard deviation of the ratio of the peak intensity of the additive element X (XK?) measured by STEM-EDX, and the sum of the peak intensity of the Ti and peak intensity of the Ba (BaL?+TiK?) measured by STEM-EDX, is less than 10.5% of the average ratio as measured at a total of five points including the three points that divide the maximum diameter of one grain of the ceramic powder into four equal parts, and two excluding the center point of the three points that divide the diameter crossing at right angles with the maximum diameter at its center point, into four equal parts.Type: GrantFiled: November 29, 2016Date of Patent: March 20, 2018Assignee: TAIYO YUDEN CO., LTD.Inventors: Kunihiko Nagaoka, Kazumichi Hiroi, Minoru Ryu, Chie Kawamura
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Publication number: 20170372841Abstract: A multilayer ceramic capacitor includes: a multilayer structure in which ceramic dielectric layers and internal electrode layers are alternately stacked, wherein: a main component of the ceramic dielectric layer is barium titanate in which a donor element having a larger valence than Ti is solid-solved and an acceptor element having a smaller valence than Ti and larger ion radius than Ti and the donor element is solid-solved; a solid-solution amount of the donor element is 0.05 mol or more and 0.3 mol or less on a presumption that an amount of the barium titanate is 100 mol and the donor element is converted into an oxide; and a solid solution amount of the accepter element is 0.02 mol or more and 0.2 mol or less on a presumption that the amount of the barium titanate is 100 mol and the acceptor element is converted into an oxide.Type: ApplicationFiled: June 14, 2017Publication date: December 28, 2017Inventors: Chie KAWAMURA, Kazumichi HIROI, Osamu HATTORI
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Publication number: 20170152187Abstract: Dielectric layers are prepared using a dielectric material that contains a ceramic powder having Ba, Ti, and additive element X which is solid-solubilized and is at least one element selected from the group consisting of Mo, Ta, Nb, and W, wherein the standard deviation of the ratio of the peak intensity of the additive element X (XK?) measured by STEM-EDX, and the sum of the peak intensity of the Ti and peak intensity of the Ba (BaL?+TiK?) measured by STEM-EDX, is less than 10.5% of the average ratio as measured at a total of five points including the three points that divide the maximum diameter of one grain of the ceramic powder into four equal parts, and two excluding the center point of the three points that divide the diameter crossing at right angles with the maximum diameter at its center point, into four equal parts.Type: ApplicationFiled: November 29, 2016Publication date: June 1, 2017Inventors: Kunihiko NAGAOKA, Kazumichi HIROI, Minoru RYU, Chie KAWAMURA
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Patent number: 9666371Abstract: A multilayer ceramic capacitor has a laminate comprising dielectric layers stacked alternately with internal electrode layers of different polarities, wherein: the dielectric layers contain ceramic grains whose primary component is BaTiO3; the ceramic grains contain at least one type of donor element (D) selected from the group that includes Nb, Mo, Ta, and W, and at least one type of acceptor element (A) selected from the group that includes Mg and Mn; and the ratio of the concentration of the donor element (D) and that of the acceptor element (A) (D/A) is greater than 1 at the center parts of the ceramic grains, while the D/A ratio is less than 1 at the outer edge parts of the ceramic grains (if A=0, then D/A=? and D=A=0 never occurs).Type: GrantFiled: January 20, 2016Date of Patent: May 30, 2017Assignee: TAIYO YUDEN CO., LTD.Inventors: Koichiro Morita, Chie Kawamura, Minoru Ryu, Katsuya Taniguchi, Kazumichi Hiroi, Yoshiki Iwazaki
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Publication number: 20160217924Abstract: A multilayer ceramic capacitor has a laminate comprising dielectric layers stacked alternately with internal electrode layers of different polarities, wherein: the dielectric layers contain ceramic grains whose primary component is BaTiO3; the ceramic grains contain at least one type of donor element (D) selected from the group that includes Nb, Mo, Ta, and W, and at least one type of acceptor element (A) selected from the group that includes Mg and Mn; and the ratio of the concentration of the donor element (D) and that of the acceptor element (A) (D/A) is greater than 1 at the center parts of the ceramic grains, while the D/A ratio is less than 1 at the outer edge parts of the ceramic grains (if A=0, then D/A=? and D=A=0 never occurs).Type: ApplicationFiled: January 20, 2016Publication date: July 28, 2016Inventors: Koichiro Morita, Chie Kawamura, Minoru Ryu, Katsuya Taniguchi, Kazumichi Hiroi, Yoshiki Iwazaki
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Patent number: 9117590Abstract: A laminated ceramic electronic component has electrode layers stacked with ceramic layers, where the thickness of each electrode layer is controlled to 0.5 ?m or less and the average size of crystal grains constituting the electrode layer is controlled to 0.1 ?m or less. The occurrence of structural defects in the laminated ceramic electronic component can be suppressed and high continuity of the electrode layers stacked with the ceramic layers is ensured.Type: GrantFiled: June 19, 2013Date of Patent: August 25, 2015Assignee: TAIYO YUDEN CO., LTD.Inventors: Yukihiro Konishi, Yusuke Kowase, Kazumichi Hiroi, Kotaro Mizuno, Ayumu Sato
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Patent number: 8946104Abstract: A dielectric ceramic whose primary component is an ABO3 compound (A contains Ba and B contains Ti) has a per-layer thickness of approx. 0.5 ?m or less, where the volume ratio to all dielectric sintered grains of those whose grain size is in a range of 0.02 ?m to 0.15 ?m is adjusted to a grain size distribution of 1% to 10%. High dielectric constant and high reliability can be achieved at the same time with the dielectric ceramic.Type: GrantFiled: June 19, 2013Date of Patent: February 3, 2015Assignee: Taiyo Yuden Co., Ltd.Inventors: Yukihiro Konishi, Yusuke Kowase, Kazumichi Hiroi, Kotaro Mizuno, Ayumu Sato
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Publication number: 20130342956Abstract: A laminated ceramic electronic component has electrode layers stacked with ceramic layers, where the thickness of each electrode layer is controlled to 0.5 ?m or less and the average size of crystal grains constituting the electrode layer is controlled to 0.1 ?m or less. The occurrence of structural defects in the laminated ceramic electronic component can be suppressed and high continuity of the electrode layers stacked with the ceramic layers is ensured.Type: ApplicationFiled: June 19, 2013Publication date: December 26, 2013Inventors: Yukihiro KONISHI, Yusuke KOWASE, Kazumichi HIROI, Kotaro MIZUNO, Ayumu SATO
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Publication number: 20130342957Abstract: A dielectric ceramic whose primary component is an ABO3 compound (A contains Ba and B contains Ti) has a per-layer thickness of approx. 0.5 ?m or less, where the volume ratio to all dielectric sintered grains of those whose grain size is in a range of 0.02 ?m to 0.15 ?m is adjusted to a grain size distribution of 1% to 10%. High dielectric constant and high reliability can be achieved at the same time with the dielectric ceramic.Type: ApplicationFiled: June 19, 2013Publication date: December 26, 2013Inventors: Yukihiro KONISHI, Yusuke KOWASE, Kazumichi HIROI, Kotaro MIZUNO, Ayumu SATO