Patents by Inventor Hitoshi Amita

Hitoshi Amita 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).

  • Patent number: 7811355
    Abstract: The present invention relates to niobium powder for a capacitor, comprising a niobium layer and a mixed layer of silicon nitride and niobium, the mixed layer being present in the vicinity of the powder particle surface; granulated niobium powder thereof; a niobium sintered body using the niobium powder and the granulated powder; and a capacitor using the sintered body as one electrode. The niobium powder for a capacitor of the present invention enables to produce a niobium capacitor having a high capacitance, a low leakage current, a low ESR and good tan ? characteristics and being excellent particularly in the properties of the breakdown voltage and soldering heat resistance.
    Type: Grant
    Filed: November 9, 2004
    Date of Patent: October 12, 2010
    Assignee: Showa Denko K.K.
    Inventors: Kazuhiro Omori, Hitoshi Amita
  • Publication number: 20090256014
    Abstract: The present invention provides a method of efficiently producing niobium powder, niobium alloy powder, niobium hydride powder or niobium hydride alloy powder for a capacitor, which enables production of capacitor having a high capacitance per unit mass and good leakage current characteristics with narrow variation, and also provides a production method for sintered body and a capacitor using the niobium powder, niobium alloy powder, niobium hydride powder or niobium hydride alloy powder. According to the present invention, by grinding niobium hydride powder or niobium hydride alloy powder with a grinding aid having a density of 2 to 3.6 g/cm3 and a fracture toughness value of 1.5 MPa·m1/2 or more, such as beads made of silicon nitride or a compound containing silicon nitride, a niobium powder with high capacitance can be efficiently produced.
    Type: Application
    Filed: June 19, 2009
    Publication date: October 15, 2009
    Applicant: SHOWA DENKO K.K.
    Inventors: Hitoshi AMITA, Kazuhiro OMORI
  • Patent number: 7594937
    Abstract: The invention provides a method of manufacturing a porous anode for a solid electrolytic capacitor, comprising a step of subjecting a molded body containing powder of at least one material selected from oxygen-containing niobium material and oxygen-containing tantalum material and a pore-forming agent which is solid at reduction temperature to reduction reaction using reducing agent and another step of removing the pore-forming agent from the reduction reaction product and a solid electrolytic capacitor using an anode obtained thereby. As niobium material and tantalum material, at least one material selected from niobium, niobium alloy, niobium compound, tantalum, tantalum alloy and tantalum compound is used respectively.
    Type: Grant
    Filed: November 28, 2005
    Date of Patent: September 29, 2009
    Assignee: Showa Denko K.K.
    Inventors: Hitoshi Amita, Kazuhiro Omori
  • Publication number: 20080106852
    Abstract: The invention provides a method of manufacturing a porous anode for a solid electrolytic capacitor, comprising a step of subjecting a molded body containing powder of at least one material selected from oxygen-containing niobium material and oxygen-containing tantalum material and a pore-forming agent which is solid at reduction temperature to reduction reaction using reducing agent and another step of removing the pore-forming agent from the reduction reaction product and a solid electrolytic capacitor using an anode obtained thereby. As niobium material and tantalum material, at least one material selected from niobium, niobium alloy, niobium compound, tantalum, tantalum alloy and tantalum compound is used respectively.
    Type: Application
    Filed: November 28, 2005
    Publication date: May 8, 2008
    Applicant: SHOWA DENKO K.K.
    Inventors: Hitoshi Amita, Kazuhiro Omori
  • Patent number: 7357291
    Abstract: Solder metal consists essentially of 8.8 to 5.0 mass % of Zn, 0.05 to 0 mass % of Bi and the balance of Sn and unavoidable impurities.
    Type: Grant
    Filed: January 30, 2003
    Date of Patent: April 15, 2008
    Assignee: Showa Denko K.K.
    Inventors: Takashi Shoji, Ayako Nishioka, Tadatoshi Kurozumi, Yoshinori Shibuya, Hitoshi Amita
  • Publication number: 20070137434
    Abstract: The present invention relates to niobium powder for a capacitor, comprising a niobium layer and a mixed layer of silicon nitride and niobium, the mixed layer being present in the vicinity of the powder particle surface; granulated niobium powder thereof; a niobium sintered body using the niobium powder and the granulated powder; and a capacitor using the sintered body as one electrode. The niobium powder for a capacitor of the present invention enables to produce a niobium capacitor having a high capacitance, a low leakage current, a low ESR and good tan ? characteristics and being excellent particularly in the properties of the breakdown voltage and soldering heat resistance.
    Type: Application
    Filed: November 9, 2004
    Publication date: June 21, 2007
    Inventors: Kazuhiro Omori, Hitoshi Amita
  • Publication number: 20060260437
    Abstract: The present invention provides a method of efficiently producing niobium powder, niobium alloy powder, niobium hydride powder or niobium hydride alloy powder for a capacitor, which enables production of capacitor having a high capacitance per unit mass and good leakage current characteristics with narrow variation, and also provides a production method for sintered body and a capacitor using the niobium powder, niobium alloy powder, niobium hydride powder or niobium hydride alloy powder. According to the present invention, by grinding niobium hydride powder or niobium hydride alloy powder with a grinding aid having a density of 2 to 3.6 g/cm3 and a fracture toughness value of 1.5 MPa·m1/2 or more, such as beads made of silicon nitride or a compound containing silicon nitride, a niobium powder with high capacitance can be efficiently produced.
    Type: Application
    Filed: October 6, 2005
    Publication date: November 23, 2006
    Inventors: Hitoshi Amita, Kazuhiro Omori
  • Publication number: 20060071051
    Abstract: Solder metal consists essentially of 8.8 to 5.0 mass % of Zn, 0.05 to 0 mass % of Bi and the balance of Sn and unavoidable impurities.
    Type: Application
    Filed: January 30, 2002
    Publication date: April 6, 2006
    Inventors: Takashi Shoji, Ayako Nishioka, Tadatoshi Kurozumi, Yoshinori Shibuya, Hitoshi Amita
  • Patent number: 6881278
    Abstract: A solder powder comprises solder particles having a distribution such that the number of particles having a particle diameter of 20 ?m or less is 30% or less, wherein the oxygen content is 500 ppm or less. A flux for solder paste comprises an organic acid component consisting of an organic acid ester and an ester decomposer catalyst, an organic halogen compound, a reducing agent and a resin component. A solder paste mainly comprises a flux and a solder powder, wherein the water content of the solder paste is 0.5% by weight or less.
    Type: Grant
    Filed: April 7, 2003
    Date of Patent: April 19, 2005
    Assignee: Showa Denko K.K.
    Inventors: Hitoshi Amita, Takashi Shoji, Shunsuke Nagasaki, Yoshinori Shibuya, Isamu Taguchi, Noriko Murase
  • Publication number: 20030200836
    Abstract: A solder powder comprises solder particles having a distribution such that the number of particles having a particle diameter of 20 &mgr;m or less is 30% or less, wherein the oxygen content is 500 ppm or less. A flux for solder paste comprises an organic acid component consisting of an organic acid ester and an ester decomposer catalyst, an organic halogen compound, a reducing agent and a resin component. A solder paste mainly comprises a flux and a solder powder, wherein the water content of the solder paste is 0.5% by weight or less.
    Type: Application
    Filed: April 7, 2003
    Publication date: October 30, 2003
    Applicant: SHOWA DENKO K.K.
    Inventors: Hitoshi Amita, Takashi Shoji, Shunsuke Nagasaki, Yoshinori Shibuya, Isamu Taguchi, Noriko Murase
  • Publication number: 20020046627
    Abstract: A solder powder comprises solder particles having a distribution such that the number of particles having a particle diameter of 20 &mgr;m or less is 30% or less, wherein the oxygen content is 500 ppm or less. A flux for solder paste comprises an organic acid component consisting of an organic acid ester and an ester decomposer catalyst, an organic halogen compound, a reducing agent and a resin component. A solder paste mainly comprises a flux and a solder powder, wherein the water content of the solder paste is 0.5% by weight or less.
    Type: Application
    Filed: September 14, 2001
    Publication date: April 25, 2002
    Inventors: Hitoshi Amita, Takashi Shoji, Shunsuke Nagasaki, Yoshinori Shibuya, Isamu Taguchi, Noriko Murase
  • Publication number: 20010042779
    Abstract: To provide a solder paste having excellent storage stability; a method for soldering, which method is highly reliable and suitable for producing fine-pitch mounted wiring boards and a variety of parts; and a joint produced through soldering.
    Type: Application
    Filed: February 6, 2001
    Publication date: November 22, 2001
    Inventors: Hitoshi Amita, Noriko Murase, Takashi Shoji