Patents by Inventor Kozo Ogi

Kozo Ogi 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: 10458004
    Abstract: To provide a silver-bismuth powder, which includes: silver; and bismuth, wherein a mass ratio (silver:bismuth) of the silver to the bismuth is 95:5 to 40:60, wherein a cumulative 50% point of particle diameter (D50) of the silver-bismuth powder in a volume-based particle size distribution thereof as measured by a laser diffraction particle size distribution analysis is 0.1 ?m to 10 ?m, and wherein an oxygen content of the silver-bismuth powder is 5.5% by mass or less.
    Type: Grant
    Filed: October 21, 2015
    Date of Patent: October 29, 2019
    Assignee: DOWA Electronics Materials Co., Ltd.
    Inventors: Kozo Ogi, Kenichi Inoue, Atsushi Ebara, Akihiro Asano, Hideyuki Fujimoto, Takahiro Yamada
  • Publication number: 20190194778
    Abstract: An object of the present invention is to provide metal powder that can be used to form an external electrode, which is excellent in solder wettability and solder leach resistance while having a layer structure with fewer layers than in the related art and, furthermore, is excellent in electrical conductivity. This silver-coated alloy powder comprises a coating layer on a surface of an alloy core particle containing copper, nickel, zinc, and inevitable impurities, the coating layer containing silver.
    Type: Application
    Filed: August 31, 2017
    Publication date: June 27, 2019
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Kyoso MASUDA, Kenichi INOUE, Yuki KANESHIRO, Atsushi EBARA, Yoshiyuki MICHIAKI, Kozo OGI, Takahiro YAMADA, Masahiro YOSHIDA
  • Patent number: 10062473
    Abstract: A silver-coated copper alloy powder, which has a low volume resistivity and excellent storage stability (reliability), is produced by coating a copper alloy powder, which has a chemical composition comprising 1 to 50 wt % of at least one of nickel and zinc and the balance being copper and unavoidable impurities (preferably a copper alloy powder wherein a particle diameter (D50 diameter) corresponding to 50% of accumulation in cumulative distribution of the copper alloy powder, which is measured by a laser diffraction particle size analyzer, is 0.1 to 15 ?m), with 7 to 50 wt % of a silver containing layer, preferably a layer of silver or an silver compound.
    Type: Grant
    Filed: January 15, 2013
    Date of Patent: August 28, 2018
    Assignee: Dowa Electronics Materials Co., Ltd.
    Inventors: Kenichi Inoue, Kozo Ogi, Atsushi Ebara, Yuto Hiyama, Takahiro Yamada, Toshihiko Ueyama
  • Publication number: 20160040271
    Abstract: To provide a silver-bismuth powder, which includes: silver; and bismuth, wherein a mass ratio (silver:bismuth) of the silver to the bismuth is 95:5 to 40:60, wherein a cumulative 50% point of particle diameter (D50) of the silver-bismuth powder in a volume-based particle size distribution thereof as measured by a laser diffraction particle size distribution analysis is 0.1 ?m to 10 ?m, and wherein an oxygen content of the silver-bismuth powder is 5.5% by mass or less.
    Type: Application
    Filed: October 21, 2015
    Publication date: February 11, 2016
    Inventors: Kozo OGI, Kenichi INOUE, Atsushi EBARA, Akihiro ASANO, Hideyuki FUJIMOTO, Takahiro YAMADA
  • Patent number: 8992701
    Abstract: After a reducing agent is added to a water reaction system containing silver ions to deposit silver particles by reduction, the silver particles are dried to obtain a silver powder which is heat-treated at a temperature of higher than 100° C. and lower than 400° C. The silver powder thus heat-treated has a maximum coefficient of thermal expansion of not greater than 1.5% at a temperature of 50° C. to 800° C., and has no heating peak when the silver powder is heated from 50° C. to 800° C. The silver powder has an ignition loss of not greater than 1.0% when the silver powder is ignited until the weight of the silver powder is constant at 800° C. The silver powder has a tap density of not less than 2 g/cm3 and a BET specific surface area of not greater than 5 m2/g.
    Type: Grant
    Filed: May 10, 2012
    Date of Patent: March 31, 2015
    Assignee: Dowa Mining Co., Ltd.
    Inventors: Takatoshi Fujino, Kozo Ogi
  • Publication number: 20140346413
    Abstract: A silver-coated copper alloy powder, which has a low volume resistivity and excellent storage stability (reliability), is produced by coating a copper alloy powder, which has a chemical composition comprising 1 to 50 wt % of at least one of nickel and zinc and the balance being copper and unavoidable impurities (preferably a copper alloy powder wherein a particle diameter (D50 diameter) corresponding to 50% of accumulation in cumulative distribution of the copper alloy powder, which is measured by a laser diffraction particle size analyzer, is 0.1 to 15 ?m), with 7 to 50 wt % of a silver containing layer, preferably a layer of silver or an silver compound.
    Type: Application
    Filed: January 15, 2013
    Publication date: November 27, 2014
    Inventors: Kenichi Inoue, Kozo Ogi, Atsushi Ebara, Yuto Hiyama, Takahiro Yamada, Toshihiko Ueyama
  • Patent number: 8282702
    Abstract: After a reducing agent is added to a water reaction system containing silver ions to deposit silver particles by reduction, the silver particles are dried to obtain a silver powder which is heat-treated at a temperature of higher than 100° C. and lower than 400° C. The silver powder thus heat-treated has a maximum coefficient of thermal expansion of not greater than 1.5% at a temperature of 50° C. to 800° C., and has no heating peak when the silver powder is heated from 50° C. to 800° C. The silver powder has an ignition loss of not greater than 1.0% when the silver powder is ignited until the weight of the silver powder is constant at 800° C. The silver powder has a tap density of not less than 2 g/cm3 and a BET specific surface area of not greater than 5 m2/g.
    Type: Grant
    Filed: November 21, 2005
    Date of Patent: October 9, 2012
    Assignee: Dowa Mining Co., Ltd.
    Inventors: Takatoshi Fujino, Kozo Ogi
  • Publication number: 20120219453
    Abstract: After a reducing agent is added to a water reaction system containing silver ions to deposit silver particles by reduction, the silver particles are dried to obtain a silver powder which is heat-treated at a temperature of higher than 100° C., and lower than 400° C. The silver powder thus heat-treated has a maximum coefficient of thermal expansion of not greater than 1.5% at a temperature of 50° C. to 800° C., and has no heating peak when the silver powder is heated from 50° C. to 800° C. The silver powder has an ignition loss of not greater than 1.0% when the silver powder is ignited until the weight of the silver powder is constant at 800° C. The silver powder has a tap density of not less than 2 g/cm3 and a BET specific surface area of not greater than 5 m2/g.
    Type: Application
    Filed: May 10, 2012
    Publication date: August 30, 2012
    Applicant: DOWA MINING CO., LTD.
    Inventors: Takatoshi Fujino, Kozo Ogi
  • Publication number: 20120045573
    Abstract: Provided is a silver conductive film, a thin film of silver comprising a sintered layer of silver particles having a mean particle size DTEM of at most 100 nm. Its specific resistance is at most 5 ??·cm, the ratio of the voids in the sintered layer is at most 3/?m2, and the film has a texture structure with a surface roughness Ra of from 10 to 100 nm. The silver conductive film having such a texture structure may be produced according to a production process comprising a step of applying a silver particle dispersion of silver particles having a mean particle size DTEM of at most 100 nm dispersed in a non-polar or poorly-polar liquid organic medium having a boiling point of from 60 to 300° C., onto a substrate to form a coating film thereon, and thereafter baking the coating film.
    Type: Application
    Filed: October 14, 2011
    Publication date: February 23, 2012
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Kimitaka SATO, Yutaka HISAEDA, Taku OKANO, Kozo Ogi
  • Patent number: 8003019
    Abstract: A silver particle dispersion liquid comprising a silver particle powder having an average particle diameter (DTEM) of 50 nm or less, the surface of the particle being covered with an organic protective material, dispersed in a non-polar or small polar liquid organic medium having a boiling point of 60 to 300° C., wherein the organic protective material is an amine compound having one or more unsaturated bonds in one molecule. The silver particle dispersion liquid can be produced by reducing a silver compound in a liquid including one or more alcohol or polyol acting as a reducing agent, wherein the reduction reaction is conducted in the presence of an amine compound having a molecular weight of 100 to 1,000 and having one or more unsaturated bonds in one molecule.
    Type: Grant
    Filed: January 9, 2007
    Date of Patent: August 23, 2011
    Assignee: Dowa Electronics Materials Co., Ltd.
    Inventors: Kimitaka Sato, Kozo Ogi
  • Publication number: 20100038603
    Abstract: A silver particle dispersion liquid comprising a silver particle powder having an average particle diameter (DTEM) of 50 nm or less, the surface of the particle being covered with an organic protective material, dispersed in a non-polar or small polar liquid organic medium having a boiling point of 60 to 300° C., wherein the organic protective material is an amine compound having one or more unsaturated bonds in one molecule. The silver particle dispersion liquid can be produced by reducing a silver compound in a liquid including one or more alcohol or polyol acting as a reducing agent, wherein the reduction reaction is conducted in the presence of an amine compound having a molecular weight of 100 to 1,000 and having one or more unsaturated bonds in one molecule.
    Type: Application
    Filed: January 9, 2007
    Publication date: February 18, 2010
    Inventors: Kimitaka Sato, Kozo Ogi
  • Publication number: 20100025639
    Abstract: A silver particle composite powder produced by mixing a silver particle powder (A) which bears on the surface of each silver particle, an organic protective layer comprising an amine compound having at least one unsaturated bond in one molecule and having a molecular weight of from 100 to 1000, and has a mean particle diameter DTEM, as determined by TEM, of at most 50 nm and a silver particle powder (B) which bears on the surface of each silver particle, an organic protective layer comprising a fatty acid having a molecular weight of from 100 to 1000 and an amine compound having a molecular weight of from 100 to 1000 with at least any one of the fatty acid and the amine compound having at least one unsaturated bond in one molecule, and has a mean particle diameter DTEM of at most 50 nm, in a blend ratio by mass, A/B of from 3/1 to 1/3 in terms of silver.
    Type: Application
    Filed: September 11, 2007
    Publication date: February 4, 2010
    Inventors: Kozo Ogi, Yutaka Hisaeda
  • Patent number: 7641817
    Abstract: There is provided a method for producing a silver powder having excellent dispersibility and capable of forming a paste which do not form suspended matters by phase separation and which is printed on a substrate to form a film having a uniform thickness. In this method, an alkali or a complexing agent is added to an aqueous silver salt containing solution to form a silver oxide containing slurry or an aqueous silver complex salt containing solution. After or before silver particles are deposited by reduction by adding a reducing agent to the silver oxide containing slurry or aqueous silver complex salt containing solution while stirring it, at least one chelating agent selected from the group consisting of compounds having an azole structure, dicarboxylic acids, hydroxy carboxylic acids and salts thereof is added to a silver power containing slurry solution as a dispersing agent.
    Type: Grant
    Filed: January 28, 2005
    Date of Patent: January 5, 2010
    Assignee: Dowa Mining Co., Ltd.
    Inventors: Hiroshi Matsushima, Kozo Ogi
  • Publication number: 20090236567
    Abstract: A powder of silver particles having an organic protective film, which has a broad particle size distribution of such that the CV value, as computed according to the following formula (1) in which the particle diameter is determined by TEM (transmission electromicroscopy), is at least 40%. The organic protective film comprises, for example, a fatty acid (oleic acid, etc.) having a molecular weight of from 100 to 1000 and an amine compound having a molecular weight of from 100 to 1000, and at least any one of the fatty acid and the amine compound has at least one unsaturated bond in one molecule.
    Type: Application
    Filed: September 11, 2007
    Publication date: September 24, 2009
    Inventors: Kozo Ogi, Taku Okano
  • Publication number: 20090053469
    Abstract: Provided is a silver conductive film, a thin film of silver comprising a sintered layer of silver particles having a mean particle size DTEM of at most 100 nm. Its specific resistance is at most 5 ??·cm, the ratio of the voids in the sintered layer is at most 3/?m2, and the film has a texture structure with a surface roughness Ra of from 10 to 100 nm. The silver conductive film having such a texture structure may be produced according to a production process comprising a step of applying a silver particle dispersion of silver particles having a mean particle size DTEM of at most 100 nm dispersed in a non-polar or poorly-polar liquid organic medium having a boiling point of from 60 to 300° C., onto a substrate to form a coating film thereon, and thereafter baking the coating film.
    Type: Application
    Filed: January 9, 2007
    Publication date: February 26, 2009
    Inventors: Kimitaka Sato, Yutaka Hisaeda, Taku Okano, Kozo Ogi
  • Patent number: 7462301
    Abstract: There is provided a method for producing a silver powder having excellent dispersibility and capable of forming a paste which do not form suspended matters by phase separation and which is printed on a substrate to form a film having a uniform thickness. In this method, an alkali or a complexing agent is added to an aqueous silver salt containing solution to form a silver oxide containing slurry or an aqueous silver complex salt containing solution. After or before silver particles are deposited by reduction by adding a reducing agent to the silver oxide containing slurry or aqueous silver complex salt containing solution while stirring it, at least one chelating agent selected from the group consisting of compounds having an azole structure, dicarboxylic acids, hydroxy carboxylic acids and salts thereof is added to a silver power containing slurry solution as a dispersing agent.
    Type: Grant
    Filed: April 17, 2007
    Date of Patent: December 9, 2008
    Assignee: Dowa Mining Co., Ltd.
    Inventors: Hiroshi Matsushima, Kozo Ogi
  • Publication number: 20080035895
    Abstract: There is provided a method for a silver powder capable of decreasing the viscosity of a photosensitive paste using the silver powder and improving the film state, sensitivity and linearity of the paste even if the particle diameter of the silver powder is small. The surface of a silver powder produced by a wet reducing method is smoothed by a surface smoothing process for mechanically causing particles of the silver powder to collide with each other, and thereafter, silver agglomerates are removed by classification. The surface smoothing process is carried out by putting a dried silver powder into an apparatus, which is capable of mechanically fluidizing particles, e.g., a mixer or mill such as a cylindrical high-speed mixer, for mechanically causing the particles to collide with each other.
    Type: Application
    Filed: October 3, 2007
    Publication date: February 14, 2008
    Inventors: Kozo Ogi, Yoshio Hasegawa
  • Publication number: 20070181858
    Abstract: There is provided a method for producing a silver powder having excellent dispersibility and capable of forming a paste which do not form suspended matters by phase separation and which is printed on a substrate to form a film having a uniform thickness. In this method, an alkali or a complexing agent is added to an aqueous silver salt containing solution to form a silver oxide containing slurry or an aqueous silver complex salt containing solution. After or before silver particles are deposited by reduction by adding a reducing agent to the silver oxide containing slurry or aqueous silver complex salt containing solution while stirring it, at least one chelating agent selected from the group consisting of compounds having an azole structure, dicarboxylic acids, hydroxy carboxylic acids and salts thereof is added to a silver power containing slurry solution as a dispersing agent.
    Type: Application
    Filed: April 17, 2007
    Publication date: August 9, 2007
    Applicant: DOWA MINING CO., LTD.
    Inventors: Hiroshi Matsushima, Kozo Ogi
  • Publication number: 20060107791
    Abstract: After a reducing agent is added to a water reaction system containing silver ions to deposit silver particles by reduction, the silver particles are dried to obtain a silver powder which is heat-treated at a temperature of higher than 100° C. and lower than 400° C. The silver powder thus heat-treated has a maximum coefficient of thermal expansion of not greater than 1.5% at a temperature of 50° C. to 800° C., and has no heating peak when the silver powder is heated from 50° C. to 800° C. The silver powder has an ignition loss of not greater than 1.0% when the silver powder is ignited until the weight of the silver powder is constant at 800° C. The silver powder has a tap density of not less than 2 g/cm3 and a BET specific surface area of not greater than 5 m2/g.
    Type: Application
    Filed: November 21, 2005
    Publication date: May 25, 2006
    Inventors: Takatoshi Fujino, Kozo Ogi
  • Publication number: 20050279970
    Abstract: A spherical silver powder which has a good dispersibility and which is capable of obtaining a good degree of sintering even if it is used for forming a paste to be fired at a low temperature of 600° C. or less to form a conductor. An aqueous solution containing a reducing agent is added to a water reaction system containing silver ions, to deposit silver particles by reduction, to produce a spherical silver powder which has a shrinkage of 5 to 15% at 500° C., a shrinkage of 10 to 20% at 600° C., a mean particle size of not greater than 5 ?m, a tap density of not less than 2 g/cm3, and a BET specific surface area of not greater than 5 m2/g.
    Type: Application
    Filed: June 15, 2005
    Publication date: December 22, 2005
    Inventors: Kozo Ogi, Takatoshi Fujino