Patents Assigned to Dowa Electronics Materials Co., Ltd.
  • Publication number: 20130153835
    Abstract: When a substrate having a low heat resistance is used, heat treatment at approximately 120° C. at which deformation does not occur is desirable. When a low resistance is achieved regardless of the type of resin used for a conductive paste, a flexible design of a paste is possible according to purposes, and fields to which the paste could be applied are expanded. Thus, a conductive paste capable of forming a conductive film exhibiting a high conductivity even at low temperatures of approximately 120° C. regardless of whether the constituting resin is a thermosetting resin or a thermoplastic resin is provided. In a method for forming a conductive film, a conductive paste in which a dicarboxylic acid having 2 to 8 carbon atoms is added to a paste including silver nanoparticles coated with an organic substance having 2 to 6 carbon atoms, a dispersion medium, and a resin is used.
    Type: Application
    Filed: October 28, 2011
    Publication date: June 20, 2013
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Takashi Hinotsu, Yuto Hiyama, Toshihiko Ueyama
  • Publication number: 20130137246
    Abstract: An object of the present invention is to provide a method for producing a Group III nitride semiconductor epitaxial substrate, a Group III nitride semiconductor element, and a Group III nitride semiconductor free-standing substrate, which have good crystallinity, with not only AlGaN, GaN, and GaInN the growth temperature of which is 1050° C. or less, but also with AlxGa1-xN having a high Al composition, the growth temperature of which is high; a Group III nitride semiconductor growth substrate used for producing these, and a method for efficiently producing those. The present invention provides a Group III nitride semiconductor growth substrate comprising a crystal growth substrate including a surface portion composed of a Group III nitride semiconductor which contains at least Al, and a scandium nitride film formed on the surface portion are provided.
    Type: Application
    Filed: January 25, 2013
    Publication date: May 30, 2013
    Applicants: DOWA ELECTRONICS MATERIALS CO., LTD., DOWA HOLDINGS CO., LTD.
    Inventors: DOWA Holdings Co., Ltd., DOWA Electronics Materials Co., Ltd.
  • Patent number: 8444872
    Abstract: Disclosed is a magnetic material having high Hc and High Curie point, which is capable of controlling such magnetic characteristics without requiring rare or expensive raw materials. Specifically disclosed is a magnetic material composed of particles of a magnetic iron oxide which is represented by the following general formula: ?-AxByFe2?x?yO3 or ?-AxByCzFe2?x?y?zO3 (wherein A, B and C each represents a metal excluding Fe and different from each other, satisfying 0<x, y, z<1), with ?-Fe2O3 as a main phase.
    Type: Grant
    Filed: May 30, 2008
    Date of Patent: May 21, 2013
    Assignees: The University of Tokyo, Dowa Electronics Materials Co., Ltd.
    Inventors: Shin-ichi Ohkoshi, Shunsuke Sakurai, Takenori Yorinaga, Kazuyuki Matsumoto, Shinya Sasaki
  • Patent number: 8441180
    Abstract: A phosphor having an excitation band relative to lights in the wide range of wavelengths from ultraviolet to visible light, and having an emission spectrum in the red range and so on, with a wide half value width, and an LED and a light source using the phosphor and emitting white and other color lights with good color rendering properties are provided. Powdered raw materials of Ca3N2 (2N), CaO (2N), AlN (3N), Si3N4 (3N), and Eu2O3 (3N) are prepared, and the respective raw materials are mixed to have a mole ratio of the respective elements of Ca:Al:Si:Eu=0.985:1:1:0.015. The mixed raw materials are fired at 1000° C. or higher in an inert atmosphere for three hours, and thereafter pulverized to obtain a phosphor having a composition of CaAlSiN2.83O0.25:Eu, which is one example of the phosphor satisfying the above described object.
    Type: Grant
    Filed: January 3, 2011
    Date of Patent: May 14, 2013
    Assignees: Dowa Electronics Materials Co., Ltd., Nichia Corporation
    Inventors: Akira Nagatomi, Masahiro Gotoh, Kenji Sakane, Shuji Yamashita
  • Patent number: 8426893
    Abstract: An epitaxial substrate for electronic devices is provided, which can improve vertical breakdown voltage and provides a method of producing the same. The epitaxial substrate includes a conductive SiC single crystal substrate, a buffer as an insulating layer on the SiC single crystal substrate, and a main laminate formed by epitaxially growing a plurality of Group III nitride layers on the buffer. Further, the buffer includes at least an initial growth layer in contact with the SiC single crystal substrate and a superlattice laminate having a superlattice multi-layer structure on the initial growth layer. The initial growth layer is made of a Ba1Alb1Gac1Ind1N material. Furthermore, the superlattice laminate is configured by alternately stacking a first layer made of a Ba2Alb2Gac2Ind2N material and a second layer made of a Ba3Alb3Gac3Ind3N material having a different band gap from the first layer.
    Type: Grant
    Filed: May 10, 2010
    Date of Patent: April 23, 2013
    Assignee: Dowa Electronics Materials Co., Ltd.
    Inventors: Tetsuya Ikuta, Jo Shimizu, Tomohiko Shibata, Ryo Sakamoto, Tsuneo Ito
  • Publication number: 20130095997
    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: Application
    Filed: May 10, 2011
    Publication date: April 18, 2013
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Yoshiyuki Michiaki, Takuma Honda, Shin Hamada
  • Patent number: 8420165
    Abstract: Provided is a method for producing a silver fine powder covered with an organic substance, which comprises a step of mixing (i) a dispersion of silver particles covered with a protective material X1 that comprises an organic compound having an unsaturated bond and having a molecular weight of from 150 to 1000 in a liquid organic medium A, (ii) a protective material X2 that comprises an organic compound of which the number of the carbon atoms constituting the carbon skeleton is smaller than that of the organic compound to constitute the protective material X1, and (iii) a liquid organic medium B of which the ability to dissolve the protective material X1 therein is higher than that of the liquid organic medium A, thereby promoting the dissolution of the protective material X1 in the liquid organic medium B and the adhesion of the protective material X2 to the surface of the silver particles.
    Type: Grant
    Filed: May 28, 2008
    Date of Patent: April 16, 2013
    Assignees: Dowa Electronics Materials Co., Ltd., Tokohu University
    Inventors: Kimitaka Sato, Balachandran Jeyadevan, Kazuyuki Tohji
  • Publication number: 20130087807
    Abstract: In heteroepitaxially growing a group-III nitride semiconductor on a Si single crystal substrate, the occurrence of cracks initiating in the wafer edge portion can be suppressed. Region A is an outermost peripheral portion outside the principal surface, being a bevel portion tapered. Regions B and C are on the same plane (the principal surface), region B (mirror-surface portion) being the center portion of the principal surface, and region C a region in the principal surface edge portion surrounding region B. The principal surface has a plane orientation, and in region B, is mirror-surface-finished. Region B occupies most of the principal surface of this Si single crystal substrate, and a semiconductor device is manufactured therein. Region C (surface-roughened portion) has a plane orientation as with region B, however, region B is mirror-surface-finished, whereas region C is surface-roughened.
    Type: Application
    Filed: June 24, 2011
    Publication date: April 11, 2013
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Tetsuya Ikuta, Daisuke Hino, Tomohiko Shibata
  • Publication number: 20130081759
    Abstract: Provided is a bonding material which enables formation of a bonded article in nitrogen, and can exhibit bonding strength to withstand practical use while having reduced bonding fluctuations between samples without a heat treatment procedure under pressurized or high temperature conditions. The bonding material comprises: silver nanoparticles having an average primary particle diameter of 1 to 200 nm and coated with an organic substance having 8 carbon atoms or less; a dispersion medium having a boiling point of 230° C. or higher; and a flux component including an organic matter having at least two carboxyl groups. Particularly, it is preferable to use the silver nanoparticles and submicron silver particles in combination.
    Type: Application
    Filed: June 10, 2011
    Publication date: April 4, 2013
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Keiichi Endoh, Yutaka Hisaeda, Akihiro Miyazawa, Aiko Nagahara, Toshihiko Ueyama
  • Patent number: 8410472
    Abstract: An epitaxial substrate for an electronic device having a Si single crystal substrate, a buffer as an insulating layer formed on the Si single crystal substrate, and a main laminated body formed by plural group III nitride layers epitaxially grown on the buffer, wherein a lateral direction of the epitaxial substrate is defined as an electric current conducting direction. The buffer including at least an initially grown layer in contact with the Si single crystal substrate and a superlattice laminate constituted of a superlattice multilayer structure on the initially grown layer.
    Type: Grant
    Filed: December 14, 2009
    Date of Patent: April 2, 2013
    Assignee: Dowa Electronics Materials Co., Ltd.
    Inventors: Tetsuya Ikuta, Jo Shimizu, Tomohiko Shibata
  • Patent number: 8404359
    Abstract: A solder layer and an electronic device bonding substrate using the layer are provided which avoid deteriorating qualities of the electronic device to be bonded. In a solder layer 14 free from lead and formed on a substrate 11 or an electronic device bonding substrate 10 having such a solder layer, the solder layer 14 has a specific resistance of not more than 0.4 ?·?m. The electronic device bonding substrate 10 can have a thermal resistance of not more than 0.5 K/W and a thickness of not more than 10 ?m. Then, voids contained in the solder layer 14 have a maximum diameter of not more than 0.5 ?m and the substrate can be a submount substrate.
    Type: Grant
    Filed: March 30, 2007
    Date of Patent: March 26, 2013
    Assignee: Dowa Electronics Materials Co., Ltd.
    Inventors: Yoshikazu Oshika, Masayuki Nakano
  • Publication number: 20130048902
    Abstract: A metal magnetic powder having a metal magnetic phase mainly composed of ferromagnetic elements, and composed of particles containing one or more kinds of elements selected from rare earth elements including Y, and Al, Si. And the method for producing the metal magnetic powder, including the steps of: eluting the non-magnetic components in the particles under an action of a reducing agent acting on the metal magnetic powder, in a solution containing a complexing agent capable of forming the complex with the non-magnetic components; and forming an oxide layer on the particles in the solution after eluting the non-magnetic components into the solution, without drying the particles.
    Type: Application
    Filed: March 31, 2011
    Publication date: February 28, 2013
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Hirohisa Omoto, Takayuki Kikuchi, Toshihiko Ueyama
  • Patent number: 8357222
    Abstract: A metal magnetic powder for a magnetic recording medium is provided whose particles have a metal magnetic phase, composed mainly of Fe or Fe plus Co, and an oxide layer, wherein the average major axis length of the powder particles is 10-50 nm, the average particle volume including the oxide layer is 5,000 nm3 or less, the atomic ratio (R+Al+Si)/(Fe+Co) calculated using the content values (at. %) of the elements contained in the powder particles is 20% or less, where R is rare earth element (Y being treated as a rare earth element). The metal magnetic powder is obtained by using a complexing agent and a reducing agent to elute nonmagnetic constituents after firing. The metal magnetic powder exhibits a large saturation magnetization as for its particle volume while maintaining weatherability comparable to the conventional level and is suitable for a coated-type magnetic recording medium.
    Type: Grant
    Filed: November 23, 2010
    Date of Patent: January 22, 2013
    Assignee: DOWA Electronics Materials Co., Ltd.
    Inventors: Takayuki Yoshida, Masatoshi Nakayama, Ryota Igarashi
  • Publication number: 20130011781
    Abstract: A carrier core particle for an electrophotographic developer includes a composition expressed by a general formula: MnxFe3?xO4+y (0<x?1, 0<y), a full width at half maximum z of the most intense peak (311) plane in a powder X-ray diffraction pattern satisfying 0.16 (degree)?z, and a magnetization of 50 emu/g or higher in an external magnetic field of 1000 Oe.
    Type: Application
    Filed: March 8, 2011
    Publication date: January 10, 2013
    Applicants: DOWA IP CREATION CO., LTD., DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Takeshi Kawauchi, Sho Ogawa
  • Publication number: 20130011780
    Abstract: A carrier core particle for an electrophotographic developer includes a core composition expressed by a general formula: MnxFe3?xO4+y (0<x?1, 0<y) as a main ingredient, 0.1 wt % or more of Si, and 0.03 wt % or more of at least one metal element selected from the group consisting of Ca, Sr and Mg.
    Type: Application
    Filed: March 29, 2011
    Publication date: January 10, 2013
    Applicants: DOWA IP CREATION CO., LTD., DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Takeshi Kawauchi, Sho Ogawa
  • Patent number: 8343453
    Abstract: To provide a carrier for two-component electrophotographic developer not only having excellent fluidity but also having proper surface irregularities necessary for imparting electric charge, without generating cracks/chipping of particles even under an influence of stirring stress over a long period of time. A particle surface has raised parts of striped pattern extending almost continuously in a plurality of directions while being superposed on one another, with a surface formed with raised parts of striped pattern occupying 80% or more of the whole surface of a particle. Depths of grooves between the adjacent raised parts are 0.05 ?m or more and 0.2 ?m or less, average surface roughness Ra is 0.1 ?m or more and 0.3 ?m or less, roundness is 0.90 or more, and average particle size is 15 ?m or more and 100 ?m or less, and a carrier core material thus constituted is coated with resin. Thus, the carrier for two-component electrophotographic developer is prepared.
    Type: Grant
    Filed: March 26, 2008
    Date of Patent: January 1, 2013
    Assignees: Dowa Electronics Materials Co., Ltd., Dowa IP Creation Co., Ltd.
    Inventors: Tomoya Yamada, Isao Fujita, Yoshiaki Aiki
  • Patent number: 8344356
    Abstract: A semiconductor material is provided comprising: a composition graded layer, formed on a Si substrate or an interlayer formed thereon, comprising a composition of AlXGa1-XN graded such that a content ratio of Al in the composition decreases continuously or discontinuously in a crystal growing direction; a superlattice composite layer, formed on the composition graded layer, comprising a high Al-containing layer comprising a composition of AlYGa1-YN and a low Al-containing layer comprising a composition of AlZGa1-ZN that are laminated alternately; and a nitride semiconductor layer formed on the superlattice composite layer.
    Type: Grant
    Filed: December 17, 2008
    Date of Patent: January 1, 2013
    Assignees: Dowa Electronics Materials Co., Ltd., National University Corporation Nagoya Institute of Technology
    Inventors: Ryo Sakamoto, Jo Shimizu, Tsuneo Ito, Takashi Egawa
  • Publication number: 20120326209
    Abstract: To provide a semiconductor device including a functional laminate having flatness and crystallinity improved by effectively passing on the crystallinity and flatness improved in a buffer to the functional laminate, and to provide a method of producing the semiconductor device; in the semiconductor device including the buffer and the functional laminate having a plurality of nitride semiconductor layers, the functional laminate includes a first n-type or i-type AlxGa1-xN layer (0?x<1) on the buffer side, and an AlzGa1-zN adjustment layer containing p-type impurity, which has an approximately equal Al composition to the first AlxGa1-xN layer (x?0.05?z?x+0.05, 0?z<1) is provided between the buffer and the functional laminate.
    Type: Application
    Filed: March 1, 2011
    Publication date: December 27, 2012
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Yoshikazu Ooshika, Tetsuya Matsuura
  • Patent number: 8337714
    Abstract: The present invention provides ferrite powders for bonded magnet capable of suppressing increase of SFD, while widening a particle size distribution for obtaining flowability and compressed density, and also capable of suppressing deterioration of orientation and magnetizability, and provides a process for a production magnetoplumbite-type ferrite powders containing an oxide of at least one or more kinds of transition metals selected from a group consisting of Zr, Ti, Zn, Co, Mn, and Ni, having a mean particle size of 0.20 ?m or more and less than 5.00 ?m, being the ferrite powders for bonded magnet with the ratio of particles having particle size of 1 ?m or less being 20 mass % or more in the magnetoplumbite-type ferrite powder size distribution obtained by a laser diffraction type particle size distribution analyzer.
    Type: Grant
    Filed: September 26, 2008
    Date of Patent: December 25, 2012
    Assignees: Dowa Electronics Materials Co., Ltd., Dowa F-Tec Co., Ltd.
    Inventors: Kazuyuki Nakaue, Shinichi Suenaga, Masahiro Kojima, Hiroya Ikeda, Satoru Tsuboi
  • Patent number: RE44162
    Abstract: To provide a phosphor for an electron beam excitation with a small deterioration in an emission efficiency and capable of maintaining a high luminance, even when an excitation density of an electron beam for a phosphor excitation is increased. As raw materials, Ca3N2(2N), AlN(3N), Si3N4(3N), and Eu2O3(3N) are prepared, and the raw materials thus prepared are measured and mixed, so that a molar ratio of each element becomes (Ca+Eu):Al:Si=1:1:1. Then, the mixture thus obtained is maintained and fired for at 1500° C. for 3 hours, and thereafter crushed, to manufacture the phosphor having a composition formula Ca0.985SiAlN3:Eu0.015.
    Type: Grant
    Filed: May 4, 2011
    Date of Patent: April 23, 2013
    Assignees: Dowa Electronics Materials Co., Ltd., Nichia Corporation
    Inventors: Masahiro Gotoh, Akira Nagatomi, Kenji Sakane, Shuji Yamashita