Patents Assigned to Dowa Electronics Materials Co., Ltd.
  • Patent number: 10504548
    Abstract: An e-type iron-based oxide magnetic particle powder has narrow particle size distribution and has a low content of fine particles which do not contribute to magnetic recording characteristics. As a result, a narrow coercive force distribution is achieved and the powder is suitable for increasing recording density of a magnetic recording medium. The powder containing substituting metal elements can be obtained by: adding an alkali to an aqueous solution containing trivalent iron ions and ions of the metals for partially substituting Fe sites to neutralize the aqueous solution to a pH of 1.5 to 2.5; then adding a hydroxycarboxylic acid; further adding the alkali to neutralize the aqueous solution to a pH of 8.0 to 9.0; washing with water a precipitation of an iron oxyhydroxide containing the substituting metal elements produced; and coating the iron oxyhydroxide containing the substituting metal elements with a silicon oxide and heating the resultant.
    Type: Grant
    Filed: September 17, 2015
    Date of Patent: December 10, 2019
    Assignee: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Kenji Sakane, Tetsuya Kawahito
  • Patent number: 10475964
    Abstract: Provided is a method of producing an n-type ohmic electrode that can form a good ohmic contact with an n-type AlxGa1-xN (0.5?x?1) layer. The method of producing an n-type ohmic electrode includes: a first step of forming a first layer 11 made of one of Ti and Hf on a surface of a layer 30; a second step of forming a second layer 12 made of Sn on the surface of the first layer 11; a third step of forming a third layer 13 made of one of V and Mo on the surface of the second layer 12; a fourth step of forming a fourth layer 14 made of Al on the surface of the third layer 13; and a fifth step of performing heat treatment on the first layer 11, the second layer 12, the third layer 13, and the fourth layer 14.
    Type: Grant
    Filed: September 2, 2016
    Date of Patent: November 12, 2019
    Assignee: DOWA Electronics Materials Co., Ltd.
    Inventor: Tatsunori Toyota
  • Patent number: 10460851
    Abstract: Provided is a silver-tellurium-coated glass powder including: a tellurium-based glass powder containing tellurium in an amount of 20% by mass or more; and a coating layer on a surface of the tellurium-based glass powder, the coating layer containing silver and tellurium as a main component. Preferable aspects include an aspect where the coating layer containing silver and tellurium as a main component further contains a component that is other than silver and tellurium and contained in the tellurium-based glass powder, and an aspect where the component that is lo other than silver and tellurium and contained in the tellurium-based glass powder contains one or more kinds selected from zinc, lead, bismuth, silicon, lithium, and aluminum.
    Type: Grant
    Filed: March 15, 2017
    Date of Patent: October 29, 2019
    Assignee: DOWA Electronics Materials Co., Ltd.
    Inventors: Hiroshi Kamiga, Taro Nakanoya, Noriaki Nogami, Kenichi Harigae
  • 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
  • Patent number: 10453596
    Abstract: There is provided a ferrite powder for bonded magnets capable of producing ferrite bonded magnets with high BHmax, excellent in MFR when converted to a compound, with high p-iHc, wherein an average particle size of particles obtained by a dry laser diffraction measurement is 5 ?m or less, a specific surface area is 1.90 m2/g or more and less than 3.00 m2/g, a compression density is 3.40 g/cm3 or more and less than 3.73 g/cm3, and a compressed molding has a coercive force of 2800 Oe or more and less than 3250 Oe.
    Type: Grant
    Filed: September 30, 2015
    Date of Patent: October 22, 2019
    Assignees: DOWA ELECTRONICS MATERIALS CO., LTD., DOWA F-TEC CO., LTD.
    Inventors: Satoru Tsuboi, Yasunobu Mishima, Keisuke Ayabe, Masayasu Senda
  • Publication number: 20190283129
    Abstract: There are provided a bonding material, which is easily printed on a metal substrate, such as a copper substrate, and which can satisfactorily bond an Si chip to the metal substrate by preventing voids from being generated in a metal bonding layer and/or on the boundary between the metal bonding layer and the Si chip or metal copper substrate even if no pre-burning is carried out when the Si chip is bonded to the metal substrate, and a bonding method using the same. In a bonding material of a metal paste containing metal particles, a solvent and a dispersant, the metal particles containing first metal particles (small particles) having an average primary particle diameter of 1 to 40 nm, second metal particles (medium particles) having an average primary particle diameter of 41 to 110 nm, and third metal particles (large particles) having an average primary particle diameter of 120 nm to 10 ?m, the weight percentages of the first, second and third metal particles being 1.
    Type: Application
    Filed: September 27, 2017
    Publication date: September 19, 2019
    Applicant: Dowa Electronics Materials Co., Ltd.
    Inventors: Keiichi Endoh, Minami Kanasugi, Hideyuki Fujimoto, Satoru Kurita
  • Publication number: 20190271694
    Abstract: To provide magnetic composite particles which can be separated from a sample solution in a short period of time using magnetism, and furthermore, have an excellent dispersion stability in the sample solution, which are magnetic composite particles in which an outer shell is formed on surfaces of core particles containing an inorganic oxide or a polymer, wherein the outer shell comprises magnetic nanoparticles and a silicon compound, the value of the volume average particle diameter (dTEM) of the magnetic composite particles measured by a transmission electron microscope is 30 nm or more to 210 nm or less, and the value of (dDLS)/(dTEM) which is the ratio of the value of the particle diameter (dDLS) of the particles measured by a dynamic light scattering method and the value of the volume average particle diameter (dTEM) is 2.0 or less.
    Type: Application
    Filed: August 31, 2017
    Publication date: September 5, 2019
    Applicants: TOHOKU UNIVERSITY, DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Daisuke NAGAO, Mikio KONNO, Haruyuki ISHII, Kumiko HAYASHI, Natsuki KOHAMA, Takayuki YOSHIDA, Toshihiko UEYAMA
  • Publication number: 20190273182
    Abstract: Provided is a semiconductor optical device with light extraction efficiency or light collecting efficiency higher than that of conventional devices and with a reduced peeling ratio of a wiring electrode portion, and a method of manufacturing the same. In the semiconductor optical, a wiring electrode portion 120 is provided on a surface of a semiconductor layer 110 that serves as a light emitting surface or a light receiving surface, the line width W1 of the wiring electrode portion 120 is 2 ?m or more and 5 ?m or less, the wiring electrode portion 120 has a metal layer 121 on the semiconductor layer 110 and a conductive hard film 122 on the metal layer 121, and the conductive hard film 122 is harder than the metal layer 121.
    Type: Application
    Filed: January 30, 2017
    Publication date: September 5, 2019
    Applicant: DOWA Electronics Materials Co., Ltd.
    Inventor: Norio TASAKI
  • Publication number: 20190259510
    Abstract: There is provided an inexpensive silver particle dispersing solution being usable as a slurry for ink jet, a method for producing the same, and a method for producing a conductive film using the silver particle dispersing solution. In a silver particle dispersing solution containing a silver powder and a solvent, the silver powder has an average primary particle diameter (DSEM) of 0.15 to 0.5 ?m, and the ratio (D50/DSEM) of a particle diameter (D50), which corresponds to 50% of accumulation in volume-based cumulative distribution of the silver powder, to the average primary particle diameter (DSEM) is not less than 1.7, the silver powder having a fatty acid adhered to the surface thereof, and the solvent containing a monohydric higher alcohol having a carbon number of 6 to 12, butyl carbitol or butyl carbitol acetate as the main component thereof.
    Type: Application
    Filed: June 11, 2017
    Publication date: August 22, 2019
    Applicant: Dowa Electronics Materials Co., Ltd.
    Inventors: Taku Okano, Noriaki Nogami
  • Patent number: 10388517
    Abstract: An epitaxial substrate for an electronic device, in which a lateral direction of the substrate is defined as a main current conducting direction and a warp configuration of the epitaxial substrate is adequately controlled, as well as a method of producing the epitaxial substrate. Specifically, the epitaxial substrate for an electron device, including: a Si single crystal substrate; and a Group III nitride laminated body formed by epitaxially growing plural Group III nitride layers on the Si single crystal substrate, wherein a lateral direction of the epitaxial substrate is defined as a main current conducting direction, is characterized in that the Si single crystal substrate is a p-type substrate having a specific resistance value of not larger than 0.01 ?·cm.
    Type: Grant
    Filed: July 16, 2012
    Date of Patent: August 20, 2019
    Assignee: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Tetsuya Ikuta, Jo Shimizu, Tomohiko Shibata
  • Patent number: 10381124
    Abstract: To provide a silver powder including alkenylsuccinic anhydride and/or alkenylsuccinic acid on a surface of the silver powder.
    Type: Grant
    Filed: August 22, 2016
    Date of Patent: August 13, 2019
    Assignee: DOWA Electronics Materials Co., Ltd.
    Inventors: Naoki Tahara, Hiroshi Kamiga
  • Patent number: 10376962
    Abstract: After preparing a silver-coated copper powder wherein the surface of a copper powder having an average particle diameter of 0.1 to 100 ?m is coated with silver, the silver-coated copper powder is sprayed into the tail flame region of a thermal plasma to cause silver on the surface of the copper powder to diffuse in the grain boundaries of copper on the inside of the copper powder, and thereafter, the surface of the copper powder is coated with silver to produce a metal composite powder wherein the percentage of the area occupied by silver on a cross section of the metal composite powder is 3 to 20% and wherein the surface thereof is coated with silver.
    Type: Grant
    Filed: October 24, 2016
    Date of Patent: August 13, 2019
    Assignee: Dowa Electronics Materials Co., Ltd.
    Inventors: Hiroaki Koubu, Noriaki Nogami
  • Publication number: 20190229333
    Abstract: There is provided a solution containing lithium and at least one of a niobium complex and a titanium complex, excellent in storage stability, and suitable for forming a coating layer capable of improving battery characteristics of an active material, and a related technique, which is the solution containing lithium, at least one of a niobium complex and a titanium complex, and ammonia, wherein an amount of the ammonia in the solution is 0.2 mass % or less.
    Type: Application
    Filed: June 28, 2017
    Publication date: July 25, 2019
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Yoshiaki AIKI, Toshihiko UEYAMA, Koji TANOUE
  • Publication number: 20190228889
    Abstract: An object of the present invention is to provide a magnetic powder having a narrow particle size distribution of epsilon-type iron oxide particles, and another object is to provide magnetic powder suitable for magnetic recording medium by improving particle size distribution, and provide epsilon-type iron oxide magnetic particles and related technologies in which a number average particle diameter of major diameters (D50) is 10 to 20 nm, a 90% cumulative particle diameter (D90) is 30 nm or less, and a geometric standard deviation (?g) of major diameters is 1.45 or less, which are obtained by TEM observation.
    Type: Application
    Filed: September 29, 2017
    Publication date: July 25, 2019
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Kazuhiro YAMAGA, Tetsuya KAWAHITO, Toshihiko UEYAMA, Kenji SAKANE
  • Patent number: 10350679
    Abstract: In a fine silver particle dispersing solution wherein 30 to 75% by weight of fine silver particles, which are coated with an organic acid having a carbon number of 5 to 8 or a derivative thereof and which have an average particle diameter of 1 to 100 nm, are dispersed in a water-based dispersion medium which is a solvent containing water as a main component, the fine silver particle dispersing solution containing ammonia and nitric acid, there is added 0.15 to 0.6% by weight of a surface regulating agent, which preferably contains a polyether-modified polydimethylsiloxane and a polyoxyethylene alkyl ether or a polyether, or 0.005 to 0.6% by weight of an antifoaming agent which is preferably a silicone antifoaming agent.
    Type: Grant
    Filed: May 12, 2015
    Date of Patent: July 16, 2019
    Assignee: Dowa Electronics Materials Co., Ltd.
    Inventors: Yu Murano, Hidefumi Fujita, Daisuke Itoh, Shuji Yamashita, Daiki Yoshihara
  • Publication number: 20190210104
    Abstract: An iron powder and method of making an iron powder. The method includes a step of neutralizing an acidic aqueous solution containing a trivalent iron ion and a phosphorus-containing ion, with an alkali aqueous solution, so as to provide a slurry of a precipitate of a hydrated oxide, or a step of adding a phosphorus-containing ion to a slurry containing a precipitate of a hydrated oxide obtained by neutralizing an acidic aqueous solution containing a trivalent iron ion with an alkali aqueous solution. A silane compound is added to the slurry so as to coat a hydrolysate of the silane compound on the precipitate of the hydrated oxide. The precipitate of the hydrated oxide after coating is recovered through solid-liquid separation, the recovered precipitate is heated to provide iron particles coated with a silicon oxide, and a part or the whole of the silicon oxide coating is dissolved and removed.
    Type: Application
    Filed: July 10, 2017
    Publication date: July 11, 2019
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Hidenori YAMAJI, Masahiro GOTOH
  • Publication number: 20190207055
    Abstract: Provided is a method of manufacturing a semiconductor optical device, which makes it possible to reduce the thickness of a semiconductor optical device including InGaAsP-based III-V compound semiconductor layers containing at least In and P to a thickness smaller than that of conventional devices, and provide a semiconductor optical device. The method of manufacturing a semiconductor optical device includes a step of forming a semiconductor laminate 30 on the InP growth substrate; a step of bonding the semiconductor laminate 30 to the support substrate 80 formed from a Si substrate, with at least the metal bonding layer 70 therebetween; and a step of removing the InP growth substrate 10.
    Type: Application
    Filed: May 30, 2017
    Publication date: July 4, 2019
    Applicant: DOWA Electronics Materials Co., Ltd.
    Inventors: Jumpei YAMAMOTO, Tetsuya IKUTA
  • 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: D857638
    Type: Grant
    Filed: February 19, 2018
    Date of Patent: August 27, 2019
    Assignee: DOWA Electronics Materials Co., Ltd.
    Inventors: Tsukasa Maruyama, Shinichi Fukushima
  • Patent number: D863238
    Type: Grant
    Filed: February 26, 2018
    Date of Patent: October 15, 2019
    Assignee: DOWA Electronics Materials Co., Ltd.
    Inventor: Ryo Sakamoto