Patents by Inventor Kyung-Ku Choi
Kyung-Ku Choi 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: 20140320246Abstract: The present invention provides a permanent magnet which is excellent in the temperature properties and the magnetic properties of which will not be significantly decreased, compared to the conventional R-T-B based permanent magnet. In the R-T-B based structure, a stacked structure of R1-T-B based crystal layer and Y-T-B based crystal layer can be formed by alternatively stacking R1-T-B and Y-T-B. In this way, a high magnetic anisotropy field of the R1-T-B based crystal layer can be maintained while the temperature coefficient of the Y-T-B based crystal layer can be improved.Type: ApplicationFiled: April 25, 2014Publication date: October 30, 2014Inventors: Ryuji HASHIMOTO, Kenichi SUZUKI, Kyung-ku CHOI, Kenichi NISHIKAWA
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Publication number: 20140320243Abstract: The present invention provides a permanent magnet whose magnetic properties will not be significantly decreased and which is excellent in the temperature properties compared to the existing R-T-B based permanent magnet. In the R-T-B based structure, a stack structure of R1-T-B based crystallizing layer and (Y,Ce)-T-B based crystallizing layer can be formed by alternatively stacking R1-T-B and (Y,Ce)-T-B. In this way, a high magnetic anisotropy field of the R1-T-B based crystallizing layer can be maintained while an improved temperature coefficient of the (Y,Ce)-T-B based crystallizing layer can be obtained. Further, a high coercivity can be obtained by adding the Ce-T-B based crystallizing layer with a low lattice distortion to the Y-T-B based crystallizing layer.Type: ApplicationFiled: April 21, 2014Publication date: October 30, 2014Applicant: TDK CORPORATIONInventors: Ryuji HASHIMOTO, Kenichi SUZUKI, Kyung-Ku CHOI
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Publication number: 20140320245Abstract: The present invention provides such a permanent magnet that its magnetic properties will not significantly decrease and it can be prepared at a lower temperature, compared to conventional R-T-B based permanent magnets. In the R-T-B based structure, a stacked structure of R1-T-B based crystal layer and Ce-T-B based crystal layer can be formed by alternatively stacking the R1-T-B based crystal layer and the Ce-T-B based crystal layer. In this way, a high magnetic anisotropy field of the R1-T-B based crystal layer can be maintained while the crystallization temperature can be lowered by the Ce-T-B based crystal layer.Type: ApplicationFiled: April 25, 2014Publication date: October 30, 2014Inventors: Ryuji HASHIMOTO, Kenichi SUZUKI, Kyung-ku CHOI
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Publication number: 20140311291Abstract: The present invention provides a permanent magnet with excellent adhesion strength with plated layer and without significant decrease in magnetic properties, compared to the conventional R-T-B based magnet. By means that the R-T-B based magnet as the raw material is applied to heating treatment for a long time, the major phase grains will form core-shell like structures in the R-T-B based magnet in which R1 and Ce are included as an essential of R. When the mass concentration of R1 and Ce in the core portion is set as ?R1 and ?Ce respectively and that of R1 and Ce in the shell portion is set as ?R1 and ?Ce respectively, the ratio (B/A) between the mass concentration ratio of R1 to Ce in the shell portion (?R1/?Ce=B) and that of R1 to Ce in the core portion (?R1/?Ce=A) is 1.1 or more.Type: ApplicationFiled: April 22, 2014Publication date: October 23, 2014Inventors: Yasushi ENOKIDO, Kyung-Ku CHOI, Kenichi SUZUKI, Daisuke TANAKA
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Publication number: 20140311287Abstract: The present invention provides a permanent magnet with excellent temperature characteristics and without magnetic properties significantly decreased compared to the existing R-T-B based magnet. By means that the R-T-B based magnet as the raw material is applied to heating treatment for a long time, the main phase grains will turn into core-shell like, and said R-T-B based magnet comprises main phase grains having core portion and shell portion that covers the core. When the mass concentration of RI and Y in the core portion is set as ?R1 and ?Y respectively and the mass concentration of R1 and Y in the shell portion is set as ?R1 and ?Y respectively, the ratio (B/A) between the mass concentration ratio of R1 to Y in the shell portion (?R1/?Y=B) and the mass concentration ratio of R1 to Y in the core portion (?R1/?Y=A) is 1.1 or more.Type: ApplicationFiled: April 16, 2014Publication date: October 23, 2014Applicant: TDK CORPORATIONInventors: Yasushi ENOKIDO, Kyung-Ku CHOI, Ryuji HASHIMOTO, Daisuke TANAKA
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Patent number: 8841226Abstract: A dielectric ceramic composition includes a component represented by composition formula {?(xBaO.yNd2O3.zTiO2)+?(2MgO.SO2)} as a main component and zinc oxide, boron oxide, and a glass having a softening point equal to or lower than a certain temperature as minor components with respect to the main component. In the dielectric ceramic composition, x, y, and z that respectively represent molar ratios of BaO, Nd2O3, and TiO2 are in certain ranges and ? and ? that represent volume ratios of subcomponents (xBaO.yNd2O3.zTiO2 and 2MgO.SiO2) in the main component are in certain ranges. When the minor components are respectively represented by aZnO, bB2O3, and cglass, a, b, and c that represent mass ratios of the respective minor components to the main component are in certain ranges.Type: GrantFiled: November 15, 2012Date of Patent: September 23, 2014Assignee: TDK CorporationInventors: Raitarou Masaoka, Toshio Sakurai, Tomohiro Arashi, Kyung-Ku Choi, Kiyoshi Hatanaka
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Patent number: 8351185Abstract: The invention provides an electronic component and a manufacturing method thereof that can achieve an improved adhesion strength when the electronic component is solder-mounted onto an external substrate and can thereby obtain considerably improved electric properties and reliabilities, etc. An electronic component, which is a capacitor 1, has: a circuit element 5a formed on a substrate 2; an electrode layer 5b connected to the circuit element 5a; passivation layers 6 and 8 that cover the electrode layer 5b; and terminal electrodes 9a and 9b connected to the electrode layer 5b via via-conductors Va and Vb formed through the passivation layers 6 and 8, the terminal electrodes 9a and 9b being formed to cover the side wall of the passivation layers 6 and 8.Type: GrantFiled: August 10, 2010Date of Patent: January 8, 2013Assignee: TDK CorporationInventors: Takashi Ohtsuka, Kyung-Ku Choi, Tatsuo Namikawa, Hitoshi Yamaguchi
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Patent number: 8324509Abstract: The invention provides an electronic component and a manufacturing method thereof that: can allow electronic components to be mounted on an external substrate at a higher density than before; can adjust the height (level) of a terminal electrode as required and desired, thereby solving problems that would occur in the inspection of the conventional electronic components; and can also improve the yield in the mounting of electronic components, thereby achieving increased productivity.Type: GrantFiled: August 10, 2010Date of Patent: December 4, 2012Assignee: TDK CorporationInventors: Takashi Ohtsuka, Kyung-Ku Choi, Tatsuo Namikawa, Hitoshi Yamaguchi
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Publication number: 20110042127Abstract: The invention provides an electronic component and a manufacturing method thereof that: can allow electronic components to be mounted on an external substrate at a higher density than before; can adjust the height (level) of a terminal electrode as required and desired, thereby solving problems that would occur in the inspection of the conventional electronic components; and can also improve the yield in the mounting of electronic components, thereby achieving increased productivity.Type: ApplicationFiled: August 10, 2010Publication date: February 24, 2011Applicant: TDK CORPORATIONInventors: Takashi OHTSUKA, Kyung-Ku Choi, Tatsuo Namikawa, Hitoshi Yamaguchi
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Publication number: 20110044011Abstract: The invention provides an electronic component and a manufacturing method thereof that can achieve an improved adhesion strength when the electronic component is solder-mounted onto an external substrate and can thereby obtain considerably improved electric properties and reliabilities, etc. An electronic component, which is a capacitor 1, has: a circuit element 5a formed on a substrate 2; an electrode layer 5b connected to the circuit element 5a; passivation layers 6 and 8 that cover the electrode layer 5b; and terminal electrodes 9a and 9b connected to the electrode layer 5b via via-conductors Va and Vb formed through the passivation layers 6 and 8, the terminal electrodes 9a and 9b being formed to cover the side wall of the passivation layers 6 and 8.Type: ApplicationFiled: August 10, 2010Publication date: February 24, 2011Applicant: TDK CORPORATIONInventors: Takashi OHTSUKA, Kyung-Ku Choi, Tatsuo Namikawa, Hitoshi Yamaguchi
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Patent number: 7864017Abstract: It is an object of the present invention to provide an electronic component module with which circuit malfunction can be adequately prevented. There are provided a base having wiring, and a thin-film magnetic device provided on one side of the base. The thin-film magnetic device comprises a first magnetic film disposed facing the base, a second magnetic film disposed on the opposite side of the first magnetic film with respect to the base, and a thin-film coil wound so as to encircle the second magnetic film a plurality of times. The thin-film coil has a plurality of first conductor pattern components provided between the first and second magnetic films, a plurality of second conductor pattern components provided on the opposite side of the second magnetic film with respect to the first magnetic film, and a plurality of connecting conductors that connect the first conductor pattern components and the second conductor pattern components in series.Type: GrantFiled: February 19, 2008Date of Patent: January 4, 2011Assignee: TDK CorporationInventors: Toshiyasu Fujiwara, Kyung-Ku Choi
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Patent number: 7785697Abstract: The present invention provides a thin film device in which resin film does not easily separate. In a thin film device, a conductor pattern is formed on one of the main surfaces of a plate-shaped base, and the conductor pattern is covered with a resin film. This conductor pattern has a bottom face disposed on the main surface of the base, a top face that faces the bottom face and is distant from the main surface of the base, and two side faces that connect the bottom face and the top face. A depressed portion is formed in these side faces, and an insulation film extends into the depressed portion.Type: GrantFiled: June 26, 2007Date of Patent: August 31, 2010Assignee: TDK CorporationInventors: Taku Masai, Hitoshi Sakuma, Kyung-Ku Choi, Toshiyasu Fujiwara
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Patent number: 7588840Abstract: A magnetic thin film with a high resonant frequency and superior high-frequency characteristics, and a magnetic device and an inductor with superior high-frequency characteristics are provided. A planar coil and a magnetic thin film are disposed on a substrate, and an inductor is formed between connection terminals. An obliquely-grown magnetic layer in the magnetic thin film is crystal-grown in an oblique direction with respect to a surface of the substrate (an obliquely-grown magnetic body). In order to make the obliquely-grown magnetic body exhibit soft magnetism in the obliquely-grown magnetic layer, an insulator is mixed into the obliquely-grown magnetic body. The obliquely-grown magnetic layer shows in-plane magnetocrystalline anisotropy, and the in-plane magnetocrystalline anisotropy is increased, and an anisotropic magnetic field is increased.Type: GrantFiled: November 28, 2005Date of Patent: September 15, 2009Assignee: TDK CorporationInventor: Kyung-Ku Choi
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Patent number: 7498919Abstract: A thin film device, which can maintain desirable performance characteristics by reducing parasitic capacitance and increasing the Q factor even when a thin film coil of a solenoid type is equipped, is provided. The thin film coil of a solenoid type has a cross sectional width which varies with position along a film thickness direction.Type: GrantFiled: March 16, 2007Date of Patent: March 3, 2009Assignee: TDK CorporationInventors: Toshiyasu Fujiwara, Kyung-Ku Choi
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Publication number: 20080292876Abstract: There is provided a soft magnetic member comprising a resin film 11 and a soft magnetic layer formed on the resin film 11, the soft magnetic layer comprising a T-L composition layer 7, wherein T is Fe or FeCO, and L is at least one element selected from the group consisting of C, B and N, and a Co based amorphous alloy layer 3 formed on either of the surfaces of the T-L composition layer 7. The Co based amorphous alloy layer 3 is combined with the T-L composition layer 7 to give a magnetic thin film for high frequency simultaneously exhibiting a high permeability and a high saturated magnetization. The magnetic thin film for high frequency can be formed on the resin film 11 because the magnetic thin film can exhibit excellent properties without a high-temperature heat treatment.Type: ApplicationFiled: December 16, 2003Publication date: November 27, 2008Inventors: Kyung-Ku Choi, Taku Murase
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Publication number: 20080198560Abstract: It is an object of the present invention to provide an electronic component module with which circuit malfunction can be adequately prevented. There are provided a base having wiring, and a thin-film magnetic device provided on one side of the base. The thin-film magnetic device comprises a first magnetic film disposed facing the base, a second magnetic film disposed on the opposite side of the first magnetic film with respect to the base, and a thin-film coil wound so as to encircle the second magnetic film a plurality of times. The thin-film coil has a plurality of first conductor pattern components provided between the first and second magnetic films, a plurality of second conductor pattern components provided on the opposite side of the second magnetic film with respect to the first magnetic film, and a plurality of connecting conductors that connect the first conductor pattern components and the second conductor pattern components in series.Type: ApplicationFiled: February 19, 2008Publication date: August 21, 2008Applicant: TDK CORPORATIONInventors: Toshiyasu FUJIWARA, Kyung-Ku CHOI
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Patent number: 7369027Abstract: A high frequency magnetic thin film characterized by comprising a first layer made of a T-L composition (here, T is Fe or FeCo, and L is one or more of C, B, and N) and a second layer comprising a Co-based amorphous alloy arranged on either of the surfaces of the first layer. The high frequency magnetic thin film is a multilayer film of a plurality of the first layers and a plurality of the second layers or desirably is a multilayer film of alternately laminated first and second layers. The high frequency magnetic thin film of the present invention exhibits the properties such that the real part (??) of the complex permeability is 400 or more at 1 GHz, a quality factor Q (Q=??/??) is 4 or more, and a saturation magnetization is 14 kG (1.4 T) or more.Type: GrantFiled: April 4, 2007Date of Patent: May 6, 2008Assignee: TDK CorporationInventors: Kyung-Ku Choi, Taku Murase, Yohtaro Yamazaki
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Publication number: 20080003408Abstract: The present invention provides a thin film device in which resin film does not easily separate. In a thin film device, a conductor pattern is formed on one of the main surfaces of a plate-shaped base, and the conductor pattern is covered with a resin film. This conductor pattern has a bottom face disposed on the main surface of the base, a top face that faces the bottom face and is distant from the main surface of the base, and two side faces that connect the bottom face and the top face. A depressed portion is formed in these side faces, and an insulation film extends into the depressed portion.Type: ApplicationFiled: June 26, 2007Publication date: January 3, 2008Applicant: TDK CORPORATIONInventors: Taku Masai, Hitoshi Sakuma, Kyung-Ku Choi, Toshiyasu Fujiwara
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Publication number: 20070230049Abstract: A thin film device is provided which is capable of improving a Q value when employing a thin film coil wound on a magnetic film. In the thin film coil wound on an upper magnetic film, the thickness (TA) of lower coil portions in between a lower magnetic film and the upper magnetic film is larger than the thickness (TB) of upper coil portions not in between the lower and upper magnetic films (the thickness ratio TB/TA<1). The crossover magnetic flux crossing over the first coil portions in between the first and the second magnetic films can be reduced than the case where the thickness (TA) of the lower coil portions is equal to or less than the thickness (TB) of the upper coil portions (the thickness ratio TB/TA?1).Type: ApplicationFiled: March 20, 2007Publication date: October 4, 2007Applicant: TDK CORPORATIONInventors: Toshiyasu Fujiwara, Kyung-Ku Choi
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Publication number: 20070222550Abstract: A thin film device, which can maintain desirable performance characteristics by reducing parasitic capacitance and increasing the Q factor even when a thin film coil of a solenoid type is equipped, is provided. The thin film coil of a solenoid type has a cross sectional width which varies with position along a film thickness direction.Type: ApplicationFiled: March 16, 2007Publication date: September 27, 2007Applicant: TDK CORPORATIONInventors: Toshiyasu Fujiwara, Kyung-Ku Choi