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).

  • Publication number: 20140320246
    Abstract: 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: Application
    Filed: April 25, 2014
    Publication date: October 30, 2014
    Inventors: Ryuji HASHIMOTO, Kenichi SUZUKI, Kyung-ku CHOI, Kenichi NISHIKAWA
  • Publication number: 20140320243
    Abstract: 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: Application
    Filed: April 21, 2014
    Publication date: October 30, 2014
    Applicant: TDK CORPORATION
    Inventors: Ryuji HASHIMOTO, Kenichi SUZUKI, Kyung-Ku CHOI
  • Publication number: 20140320245
    Abstract: 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: Application
    Filed: April 25, 2014
    Publication date: October 30, 2014
    Inventors: Ryuji HASHIMOTO, Kenichi SUZUKI, Kyung-ku CHOI
  • Publication number: 20140311291
    Abstract: 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: Application
    Filed: April 22, 2014
    Publication date: October 23, 2014
    Inventors: Yasushi ENOKIDO, Kyung-Ku CHOI, Kenichi SUZUKI, Daisuke TANAKA
  • Publication number: 20140311287
    Abstract: 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: Application
    Filed: April 16, 2014
    Publication date: October 23, 2014
    Applicant: TDK CORPORATION
    Inventors: Yasushi ENOKIDO, Kyung-Ku CHOI, Ryuji HASHIMOTO, Daisuke TANAKA
  • Patent number: 8841226
    Abstract: 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: Grant
    Filed: November 15, 2012
    Date of Patent: September 23, 2014
    Assignee: TDK Corporation
    Inventors: Raitarou Masaoka, Toshio Sakurai, Tomohiro Arashi, Kyung-Ku Choi, Kiyoshi Hatanaka
  • Patent number: 8351185
    Abstract: 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: Grant
    Filed: August 10, 2010
    Date of Patent: January 8, 2013
    Assignee: TDK Corporation
    Inventors: Takashi Ohtsuka, Kyung-Ku Choi, Tatsuo Namikawa, Hitoshi Yamaguchi
  • Patent number: 8324509
    Abstract: 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: Grant
    Filed: August 10, 2010
    Date of Patent: December 4, 2012
    Assignee: TDK Corporation
    Inventors: Takashi Ohtsuka, Kyung-Ku Choi, Tatsuo Namikawa, Hitoshi Yamaguchi
  • Publication number: 20110042127
    Abstract: 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: Application
    Filed: August 10, 2010
    Publication date: February 24, 2011
    Applicant: TDK CORPORATION
    Inventors: Takashi OHTSUKA, Kyung-Ku Choi, Tatsuo Namikawa, Hitoshi Yamaguchi
  • Publication number: 20110044011
    Abstract: 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: Application
    Filed: August 10, 2010
    Publication date: February 24, 2011
    Applicant: TDK CORPORATION
    Inventors: Takashi OHTSUKA, Kyung-Ku Choi, Tatsuo Namikawa, Hitoshi Yamaguchi
  • Patent number: 7864017
    Abstract: 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: Grant
    Filed: February 19, 2008
    Date of Patent: January 4, 2011
    Assignee: TDK Corporation
    Inventors: Toshiyasu Fujiwara, Kyung-Ku Choi
  • Patent number: 7785697
    Abstract: 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: Grant
    Filed: June 26, 2007
    Date of Patent: August 31, 2010
    Assignee: TDK Corporation
    Inventors: Taku Masai, Hitoshi Sakuma, Kyung-Ku Choi, Toshiyasu Fujiwara
  • Patent number: 7588840
    Abstract: 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: Grant
    Filed: November 28, 2005
    Date of Patent: September 15, 2009
    Assignee: TDK Corporation
    Inventor: Kyung-Ku Choi
  • Patent number: 7498919
    Abstract: 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: Grant
    Filed: March 16, 2007
    Date of Patent: March 3, 2009
    Assignee: TDK Corporation
    Inventors: Toshiyasu Fujiwara, Kyung-Ku Choi
  • Publication number: 20080292876
    Abstract: 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: Application
    Filed: December 16, 2003
    Publication date: November 27, 2008
    Inventors: Kyung-Ku Choi, Taku Murase
  • Publication number: 20080198560
    Abstract: 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: Application
    Filed: February 19, 2008
    Publication date: August 21, 2008
    Applicant: TDK CORPORATION
    Inventors: Toshiyasu FUJIWARA, Kyung-Ku CHOI
  • Patent number: 7369027
    Abstract: 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: Grant
    Filed: April 4, 2007
    Date of Patent: May 6, 2008
    Assignee: TDK Corporation
    Inventors: Kyung-Ku Choi, Taku Murase, Yohtaro Yamazaki
  • Publication number: 20080003408
    Abstract: 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: Application
    Filed: June 26, 2007
    Publication date: January 3, 2008
    Applicant: TDK CORPORATION
    Inventors: Taku Masai, Hitoshi Sakuma, Kyung-Ku Choi, Toshiyasu Fujiwara
  • Publication number: 20070230049
    Abstract: 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: Application
    Filed: March 20, 2007
    Publication date: October 4, 2007
    Applicant: TDK CORPORATION
    Inventors: Toshiyasu Fujiwara, Kyung-Ku Choi
  • Publication number: 20070222550
    Abstract: 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: Application
    Filed: March 16, 2007
    Publication date: September 27, 2007
    Applicant: TDK CORPORATION
    Inventors: Toshiyasu Fujiwara, Kyung-Ku Choi