Patents Assigned to Dowa Electronics Materials Co., Ltd.
  • Patent number: 9248504
    Abstract: There are provided a copper powder for conductive paste, which comprises monodisperse and spherical fine copper particles having a sharp particle size distribution and containing no coarse particles and which can form a thinner electrode film while avoiding a bad influence on electric characteristics thereof, and a method for stably producing such a copper powder for conductive paste. After copper is complexed by adding a complexing agent to an aqueous solution containing copper while blowing air into the solution, the blowing of air is stopped, and then, a reducing agent is added to the solution to deposit copper particles by reduction.
    Type: Grant
    Filed: September 12, 2011
    Date of Patent: February 2, 2016
    Assignee: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Yuki Kaneshiro, Shinichi Suenaga, Hidefumi Fujita, Minoru Kishida
  • Patent number: 9240256
    Abstract: A method of forming a bonded product using metal nanoparticles is provided. More specifically, provided is a paste containing a flux component that can form a metal phase even in an inert atmosphere. The use of this paste allows a bonding material that can give a practically acceptable bonding strength to be provided in an inert atmosphere such as a nitrogen atmosphere at low temperatures without performing conventionally used pressurization. The paste is a bonding material configured to include: silver nanoparticles having an average primary particle diameter of 1 to 200 nm and coated with an organic material having 8 or less carbon atoms; a flux component having at least two carboxyl groups; and a dispersion medium. The use of this bonding material allows materials to be bonded even at a temperature of 300° C. or lower.
    Type: Grant
    Filed: April 23, 2010
    Date of Patent: January 19, 2016
    Assignee: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Keiichi Endoh, Yutaka Hisaeda, Akihiro Miyazawa, Aiko Nagahara, Toshihiko Ueyama
  • Publication number: 20160001371
    Abstract: A soft magnetic metal powder is manufactured. An aqueous solution of at least one of aluminum, silicon, a rare-earth element (including Y), and magnesium is added into a solution containing an iron ion while blowing a gas containing oxygen thereinto, to form a precursor containing at least one of aluminum, silicon, a rare-earth element (including Y), and magnesium. The precursor is reduced to obtain a metal powder. The metal powder is further slowly oxidized with oxygen to form an oxidized film on the surface of the metal powder.
    Type: Application
    Filed: September 10, 2015
    Publication date: January 7, 2016
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Kazumasa IKARI, Masahiro GOTOH, Takayuki YOSHIDA
  • Publication number: 20150372189
    Abstract: To provide a III nitride semiconductor light emitting device in which the formation of cracks in an active layer is suppressed and the light output power is improved, a III nitride semiconductor light emitting device has an n-type cladding layer, an active layer, and a p-type cladding layer in order. The active layer has a multiple quantum-well structure in which barrier layers made of AlXGa1-XN and well layers are alternately stacked. The Al content X of the barrier layers is larger as the barrier layer is closer to a first barrier layer on the n-type cladding layer side and a second barrier layer on the p-type cladding layer side with reference to one or more of intermediate barrier layers that have the lowest Al content X min of the intermediate barrier layers.
    Type: Application
    Filed: November 28, 2013
    Publication date: December 24, 2015
    Applicant: Dowa Electronics Materials Co., Ltd.
    Inventor: Tetsuya MATSUURA
  • Publication number: 20150364814
    Abstract: There is provided a silver conductive film capable of inexpensively mass-producing conductive circuits, such as antennas for IC tags, which have excellent electrical characteristic and flexibility, by applying a silver particle dispersing solution, which contains 50-70% by weight of silver particles having a mean particle diameter of 20 nm or less, on a substrate by the flexographic printing, and then, calcining the silver particle dispersing solution to produce a silver conductive film, which contains 10-50% by volume of a sintered body of the silver particles and which has a volume resistivity of 3-100 ??·cm, a surface resistivity of 0.5?/? or less and a thickness of 1-6 ?m.
    Type: Application
    Filed: February 1, 2013
    Publication date: December 17, 2015
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Hidefumi Fujita, Shinichi Konno, Kimitaka Sato, Toshihiko Ueyama
  • Patent number: 9211587
    Abstract: There are provided a cuprous oxide powder having a smaller particle diameter than that of conventional cuprous oxide powders, and a method for producing the cuprous oxide powder by a chemical reducing process. In a method for producing a cuprous oxide powder by adding a reducing agent, such as a reducing sugar, to a solution containing copper hydroxide, which is formed by adding one of an alkali solution and a copper ion containing solution to the other thereof, to deposit cuprous oxide particles by reduction, 0.00001 to 0.04 moles (10 to 40000 ppm) of ferrous ions with respect to the amount of copper ions in the copper ion containing solution are added to the copper ion containing solution before forming copper hydroxide, to produce a cuprous oxide powder which has a mean primary particle diameter of not greater than 0.5 micrometers when it is measured by a scanning electron microscope (SEM), the cuprous oxide powder having a 50% particle diameter (D50 diameter) of not greater than 0.
    Type: Grant
    Filed: September 13, 2012
    Date of Patent: December 15, 2015
    Assignee: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Yuki Kaneshiro, Shinichi Suenaga, Akihiro Asano
  • Patent number: 9195157
    Abstract: A method for manufacturing carrier core particles for electrophotographic developer including a slurrying step (A) of making an iron-containing raw material and a strontium-containing raw material into slurry, a granulation step (B) of granulating the slurry mixture obtained in the slurrying step, and a firing step (C) of firing a powdery material, which is obtained by granulating the slurry mixture in the granulation step, at a predetermined temperature to form a magnetic phase. The slurrying step makes the iron-containing raw material into the slurry containing the iron-containing raw material having a volume diameter D50 of 1.0 to 4.0 ?m and a volume diameter D90 of 2.5 to 7.0 ?m, and makes the strontium-containing raw material into the slurry so that the carrier core particles for electrophotographic developer contain 0<y?5000 ppm, where y denotes the content of the strontium in the carrier core particles.
    Type: Grant
    Filed: March 2, 2012
    Date of Patent: November 24, 2015
    Assignees: DOWA ELECTRONICS MATERIALS CO., LTD., DOWA IP CREATION CO., LTD.
    Inventors: Takeshi Kawauchi, Tomohide Iida
  • Patent number: 9172005
    Abstract: A semiconductor light emitting diode of the present invention includes a semiconductor layer including a light emitting portion, and a pad electrode located on the semiconductor layer, the semiconductor light emitting diode further including, between the semiconductor layer and the pad electrode, a reflective portion including a light transmitting insulating layer serving as a current blocking layer located on the semiconductor layer, and a reflective layer located on the light transmitting insulating layer; a contact portion formed from an ohmic electrode in contact with the reflective portion, located on the semiconductor layer; and a conductive hard film between the reflective layer and the pad electrode, the conductive hard film having HV×t>630, where the Vickers hardness is HV (Hv) and the thickness is t (?m).
    Type: Grant
    Filed: March 9, 2012
    Date of Patent: October 27, 2015
    Assignee: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Norio Tasaki, Hidetaka Yamada, Hiroyuki Togawa
  • Patent number: 9164411
    Abstract: There is provided a carrier core material for electrophotographic developer containing a soft ferrite, expressed by (MgXMn1?X)Fe2O4 (wherein X is in a range of 0.1?X<1.), wherein an analysis value of P on the surface of the carrier core material is 0.1 mass % or more, an analysis value of Mg is 2 mass % or more, a content of Mg on the surface of the carrier core material is 2 mass % or more by EDS, and when the content of Mg in the carrier core material is expressed by M1, and the analysis value of Mg on the surface of the carrier core material by EDS is expressed by M2, a value of M2/M1 exceeds 1.0.
    Type: Grant
    Filed: June 28, 2010
    Date of Patent: October 20, 2015
    Assignees: DOWA ELECTRONICS MATERIALS CO., LTD., DOWA IP CREATION CO., LTD.
    Inventors: Masahiro Nakamura, Takeshi Kawauchi, Toshiya Kitamura
  • Publication number: 20150295129
    Abstract: A luminescent device and a manufacturing method for the luminescent device and a semiconductor device which are free from occurrence of cracks in a compound semiconductor layer due to the internal stress in the compound semiconductor layer at the time of chemical lift-off. The luminescent device manufacturing method includes forming a device region on part of an epitaxial substrate through a lift-off layer; forming a sacrificing portion, being not removed in a chemical lift-off step, around device region on epitaxial substrate; covering epitaxial substrate and semiconductor layer and forming a covering layer such that level of surface thereof in the region away from device region is lower than luminescent layer surface; removing covering layer on semiconductor layer, and that on sacrificing portion surface; forming a reflection layer on covering layer surface and semiconductor layer surface; and forming a supporting substrate by providing plating on reflection layer.
    Type: Application
    Filed: May 29, 2015
    Publication date: October 15, 2015
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Yoshitaka KADOWAKI, Tatsunori TOYOTA
  • Publication number: 20150266097
    Abstract: An aliphatic amine having a carbon number of not less than 6, such as octylamine, hexylamine or oleylamine, serving as an organic protective material is added to water serving as a solvent so that the molar ratio of the aliphatic amine with respect to silver of a silver compound is in the range of 0.05 to 6, a reducing agent, such as hydrazine or NaBH4, being added thereto so that the molar ratio of the reducing agent with respect to silver of the silver compound is in the range of 1 to 6, and the silver compound, such as a silver salt or a silver oxide, being added thereto so that the concentration of silver ions in the aqueous reaction solution is in the range of 0.01 to 1.0 mol/L, and then, the silver compound is reduced at a temperature of 10 to 50° C. to produce fine silver particles having an average primary particle diameter of 10 to 200 nm. Thus, there is provided a method for producing fine silver particles, the method being capable of inexpensively producing fine silver particles in a short time.
    Type: Application
    Filed: September 20, 2013
    Publication date: September 24, 2015
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Tomonori Shibayama, Takashi Hinotsu, Tatuya Kariyasu
  • Publication number: 20150243400
    Abstract: A method suitable for mass production of nanoparticles with a uniform particle diameter is provided. It is an object to provide a powder of the nanoparticle obtained by this method, a dispersion containing the nanoparticles, and a paste containing the nanoparticles. There is provided a method for manufacturing silver particles including the step of reducing silver in a silver solution containing a protective agent composed of an organic material and a copper component in an amount of 1 to 1,000 ppm relative to the amount of silver to obtain particles having an average particle diameter (DTEM) of 5 to 100 nm as measured using a transmission electron microscope.
    Type: Application
    Filed: April 3, 2015
    Publication date: August 27, 2015
    Applicant: DOWA Electronics Materials Co., Ltd.
    Inventors: Shuji KANEDA, Kimikazu MOTOMURA, Tatsuya KARIYASU, Yutaka HISAEDA, Kosuke IHA
  • Patent number: 9114389
    Abstract: Provided is a catalyst having the ability to combust PM at relatively low temperatures and having high HC and CO removal (conversion) efficiency even at the above operating temperature. In the catalyst composition, at least one kind of platinum group element selected from Pt, Rh, and Pd is dispersed in and supported by a platinum group-supporting carrier containing at least one kind of element selected from Zr, Al, Y, Si, Bi, Pr, and Tb, and the platinum group-supporting carrier is supported on the surface of a Ce oxide containing Ce as an essential component. The catalyst composition has both PM combustion activity and gas purification activity.
    Type: Grant
    Filed: May 10, 2011
    Date of Patent: August 25, 2015
    Assignee: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Yoshiyuki Michiaki, Takuma Honda, Shin Hamada
  • Publication number: 20150220014
    Abstract: This invention is directed to a method for manufacturing carrier core particles for electrophotographic developer containing iron, manganese, and calcium as a core composition. The method includes (A) a mixing step of mixing an iron-containing raw material, a manganese-containing raw material, and a calcium-containing raw material to prepare a mixture thereof, (C) a granulation step of granulating the mixture after the mixing step, and (D) a firing step of firing a powdery material, which is obtained by granulating the mixture in the granulation step, at a predetermined temperature to form a magnetic phase. The calcium-containing raw material is provided in a granular form, and primary particles of the calcium-containing raw material have a volume mean diameter of 1 ?m or less.
    Type: Application
    Filed: August 30, 2012
    Publication date: August 6, 2015
    Applicants: DOWA ELECTRONICS MATERIALS CO., LTD., DOWA IP CREATION CO., LTD.
    Inventors: Takeshi Kawauchi, Tomohide Iida
  • Publication number: 20150187887
    Abstract: Provided is a III nitride semiconductor device higher heat dissipation performance, and a method of manufacturing a III nitride semiconductor device which makes it possible to fabricate such a III nitride semiconductor device at higher yield. In a method of a III nitride semiconductor device, a semiconductor structure obtained by sequentially stacking an n-layer, an active layer, and a p-layer is formed on a growth substrate; a support body including a first support electrically connected to an n-layer to serve as an n-side electrode, a second support electrically connected to a p-layer to serve as a p-side electrode, and structures made of an insulator for insulation between first and second supports is formed on the p-layer side of the semiconductor structure; and the growth substrate is separated using a lift-off process. The first support and the second support are grown by plating.
    Type: Application
    Filed: July 4, 2012
    Publication date: July 2, 2015
    Applicants: DOWA ELECTRONICS MATERIALS CO., LTD., BBSA LIMITED
    Inventors: Meoung Whan Cho, Seog Woo Lee, Pil Guk Jang, Hoe Young Yang, Jin Hee Kim, Ho Kyun Rho, Se Young Moon, Ryuichi Toba, Yoshitaka Kadowaki
  • Patent number: 9034552
    Abstract: The carrier core particles for electrophotographic developer have a volume size distribution with a median particle size ranging from 30 ?m to 40 ?m, the ratio of the carrier core particles having a diameter of 22 ?m or lower in the volume size distribution is from 1.0% to 2.0%, the ratio of the carrier core particles having a diameter of 22 ?m or lower in a number size distribution is 10% or lower, and the magnetization of the carrier core particles in an external magnetic field of 1000 Oe is from 50 emu/g to 75 emu/g.
    Type: Grant
    Filed: March 1, 2012
    Date of Patent: May 19, 2015
    Assignees: DOWA ELECTRONICS MATERIALS CO., LTD., DOWA IP CREATION CO., LTD.
    Inventors: Tomohide Iida, Tomoya Yamada, Takashi Fujiwara
  • Patent number: 9034214
    Abstract: A method suitable for mass production of nanoparticles with a uniform particle diameter is provided. It is an object to provide a powder of the nanoparticle obtained by this method, a dispersion containing the nanoparticles, and a paste containing the nanoparticles. There is provided a method for manufacturing silver particles including the step of reducing silver in a silver solution containing a protective agent composed of an organic material and a copper component in an amount of 1 to 1,000 ppm relative to the amount of silver to obtain particles having an average particle diameter (DTEM) of 5 to 100 nm as measured using a transmission electron microscope.
    Type: Grant
    Filed: December 25, 2009
    Date of Patent: May 19, 2015
    Assignee: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Shuji Kaneda, Kimikazu Motomura, Tatsuya Kariyasu, Yutaka Hisaeda, Kosuke Iha
  • Publication number: 20150108392
    Abstract: In magnetic parts such as inductors and antennas using magnetic metal powder, the complex component of a magnetic permeability, which represents a loss in a GHz band, has been high. A magnetic part formed from a soft magnetic metal powder including iron as a main component can reduce a loss factor in a kHz to GHz band. The soft magnetic metal powder has an average particle diameter of 100 nm or less, an axial ratio (=major axis length/minor axis length) of 1.5 or more, a coercive force (Hc) of 39.8 to 198.9 kA/m (500 to 2500 Oe), and a saturation magnetization of 100 Am2/kg or more.
    Type: Application
    Filed: May 7, 2013
    Publication date: April 23, 2015
    Applicant: DOWA Electronics Material Co., Ltd.
    Inventors: Masahiro Gotoh, Takayuki Yoshida, Kazumasa Ikari
  • Patent number: RE45502
    Abstract: To provide a phosphor having a broad emission spectrum with a peak in the range from yellow color to red color (wavelength from 570 nm to 620 nm), having a flat excitation band with large area on the long wavelength side from near ultraviolet/ultraviolet to green color (wavelength from 250 nm to 550 nm), and excellent in emission intensity and luminance, and a method of manufacturing the same, and also a light source such as white LED using the phosphor. As raw materials, Ca3N2(2N), AlN(3N), Si3N4(3N), and Eu2O3(3N) are prepared, and out of each raw material, 0.950/3 mol of Ca3N2, 2 mol of AlN, 4/3 mol of Si3N4, and 0.050/2 mol of Eu2O3 are weighed, and the raw materials thus weighed are mixed by using a mortar. The raw materials thus mixed are put in a BN crucible, and retained/fired for 3 hours at 1700° C. in a nitrogen atmosphere, and thereafter cooled from 1700° C. to 200° C., to thereby obtain the phosphor expressed by a composition formula Ca0.950Al2Si4O0.075N7.917:Eu0.050.
    Type: Grant
    Filed: March 7, 2012
    Date of Patent: May 5, 2015
    Assignees: Dowa Electronics Materials Co., Ltd., Nichia Corporation
    Inventors: Kenji Sakane, Akira Nagatomi
  • Patent number: RE45640
    Abstract: A phosphor, which has less reduction in emission efficiency and is capable of keeping high luminance even when density of an electron beam for exciting the phosphor increases, is provided. As raw materials, Ca3N2 (2N), AlN (3N), Si3N4 (3N), and Eu2O3 (3N) are prepared, and each of the raw materials is weighed so that a mole ratio of each element is, for example, (Ca+Eu):Al:Si=1:1:1, and mixed, then the mixture is held and fired at 1500° C. under the inert atmosphere for three hours, and thereafter ground to produce a phosphor having a composition formula of Ca0.985SiAlN3:Eu0.015.
    Type: Grant
    Filed: March 9, 2012
    Date of Patent: August 4, 2015
    Assignees: DOWA ELECTRONICS MATERIALS CO., LTD., NICHIA CORPORATION
    Inventors: Masahiro Gotoh, Akira Nagatomi, Kenji Sakane, Shuji Yamashita