Patents Assigned to Dowa Electronics Materials Co., Ltd.
  • Publication number: 20170113277
    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: Application
    Filed: October 24, 2016
    Publication date: April 27, 2017
    Applicant: Dowa Electronics Materials Co., Ltd.
    Inventors: Hiroaki Koubu, Noriaki Nogami
  • Patent number: 9633770
    Abstract: An epsilon-type iron oxide having an Fe-site that is substituted with a platinum group element, provided that Fe of a D-site of the epsilon-type iron oxide is not substituted with the platinum group element.
    Type: Grant
    Filed: August 8, 2016
    Date of Patent: April 25, 2017
    Assignees: THE UNIVERSITY OF TOKYO, DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Shin-ichi Ohkoshi, Shunsuke Sakurai, Asuka Namai, Sayaka Umeda, Hiroshi Hachiya, Kazuyuki Matsumoto, Takashi Gotoh
  • Publication number: 20170077057
    Abstract: A bonding material includes: fine silver particles having an average primary particle diameter of 1 to 50 nm, each of the fine silver particles being coated with an organic compound having a carbon number of not greater than 8, such as hexanoic acid; silver particles having an average primary particle diameter of 0.5 to 4 ?m each of the silver particles being coated with an organic compound, such as oleic acid; a solvent containing a primary alcohol solvent and a terpene alcohol solvent; and a dispersant containing a phosphoric acid ester dispersant (or a phosphoric acid ester dispersant and an acrylic resin dispersant), wherein the content of the fine silver particles is in the range of from 5 wt % to 30 wt %, and the content of the silver particles is in the range of from 60 wt % to 90 wt %, the total content of the fine silver particles and the silver particles being not less than 90 wt %, and wherein the bonding material further includes a sintering aid of a monocarboxylic acid having an ether bond.
    Type: Application
    Filed: May 15, 2015
    Publication date: March 16, 2017
    Applicant: Dowa Electronics Materials Co., Ltd.
    Inventors: Keiichi Endoh, Koichi Yuzaki, Minami Nagaoka, Hiromasa Miyoshi, Saturo Kurita
  • Patent number: 9543469
    Abstract: A III nitride semiconductor epitaxial substrate having more excellent surface flatness is provided, in which the problems of crack formation and the double peaks in the shape of the EL spectrum are mitigated by employing appropriate conditions for Si doping on an AlN layer on a substrate; a III nitride semiconductor light emitting device; and methods of producing the same. A III nitride semiconductor epitaxial substrate has a substrate of which at least a surface portion is made of AlN, an undoped AlN layer formed on the substrate, an Si-doped AlN buffer layer formed on the undoped AlN layer, and a superlattice laminate formed on the Si-doped AlN buffer layer. The Si-doped AlN buffer layer has an Si concentration of 2.0×1019/cm3 or more and a thickness of 4 nm to 10 nm.
    Type: Grant
    Filed: August 6, 2014
    Date of Patent: January 10, 2017
    Assignee: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Masatoshi Iwata, Yoshikazu Ooshika
  • Patent number: 9533380
    Abstract: The occurrence of uneven drying in the center and end of a surface of a bonding layer during a desolvation process of a pre-drying step is reduced to ensure highly reliable bonding without peeling of a bonding surface even after repeated exposure to heat shock after bonding. The bonding material of the present invention to achieve the object contains silver nanoparticles coated with organic substance having 6 or less carbon atoms and having an average primary particle diameter of 10 to 30 nm as main silver particles, silver nanoparticles coated with an organic substance having 6 or less carbon atoms and having an average primary particle diameter of 100 to 200 nm as secondary silver particles, two kinds of solvents having different boiling points, and a dispersant.
    Type: Grant
    Filed: January 20, 2012
    Date of Patent: January 3, 2017
    Assignee: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Keiichi Endoh, Satoru Kurita, Minami Nagaoka
  • Patent number: 9537053
    Abstract: Provided is a high quality III nitride semiconductor device in which, not only X-shaped cracks extending from the vicinity of the corners of semiconductor structures to the center portion thereof, but also crack spots at the center portion can be prevented from being formed and can provide a method of efficiently manufacturing the III nitride semiconductor device. The III nitride semiconductor device of the present invention includes a support and two semiconductor structures having a nearly quadrangular transverse cross-sectional shape that are provided on the support. The two semiconductor structures are situated such that one side surface of one of the two semiconductor structures is placed to face one side surface of the other of them. The support covers the other three side surfaces and of the four sides of the semiconductor structures.
    Type: Grant
    Filed: September 28, 2012
    Date of Patent: January 3, 2017
    Assignees: BBSA LIMITED, DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Meoung Whan Cho, Seog Woo Lee, Ryuichi Toba, Yoshitaka Kadowaki
  • Patent number: 9537066
    Abstract: When an uneven pattern is formed on a light extraction surface composed of a semiconductor crystal by wet-etching using an alkaline solution, a plurality of convex portions cannot be formed in a desired arrangement. A method of manufacturing a semiconductor light emitting device includes a light extraction surface composed of a semiconductor crystal, wherein when the uneven pattern is formed by a plurality of convex portions on the light extraction surface, first, a plurality of impressions are formed on the light extraction surface of a semiconductor layer composed of a semiconductor crystal using a processing substrate, and next, by applying wet-etching to the light extraction surface using an alkaline solution, to thereby form convex portions with a portion where each impression is formed as a top portion, and a plurality of facets of the semiconductor crystal as a side face thereof.
    Type: Grant
    Filed: July 30, 2014
    Date of Patent: January 3, 2017
    Assignee: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventor: Yoshitaka Kadowaki
  • Patent number: 9537202
    Abstract: A silver particle dispersing solution, which contains 50-70% by weight of silver particles having an average particle diameter of 20 nm or less, is applied on a substrate by the flexographic printing, and then, calcined to produce a booster antenna wherein 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, is formed on the substrate. Thus, there is provided a booster antenna which has excellent electrical characteristics and flexibility and which can be inexpensively mass-produced.
    Type: Grant
    Filed: February 1, 2013
    Date of Patent: January 3, 2017
    Assignee: Dowa Electronics Materials Co. Ltd.
    Inventors: Daisuke Itoh, Hidefumi Fujita, Yu Murano, Shinichi Konno
  • Publication number: 20160346838
    Abstract: A copper particle dispersing solution obtained by dispersing fine copper particles having an average particle diameter of 1 to 100 nm, each of the fine copper particles being coated with an azole compound, such as benzotriazole, and coarse copper particles having an average particle diameter of 0.3 to 20 ?m in a dispersing medium, such as ethylene glycol, so as to cause the total amount of the fine copper particles and coarse copper particles to be 50 to 90% by weight and so as to cause the ratio of the weight of the fine copper particles to the weight of the coarse copper particles to be in the range of from 1:9 to 5:5, is applied on a substrate by screen printing or flexographic printing to be preliminary-fired with vacuum drying, and then, fired with light irradiation by irradiating light having a wavelength of 200 to 800 nm at a pulse period of 100 to 3000 ?m and a pulse voltage of 1600 to 3600 V, to form a conductive film on the substrate.
    Type: Application
    Filed: October 31, 2014
    Publication date: December 1, 2016
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Hidefumi Fujita, Shuji Kaneda, Daisuke Itoh
  • Patent number: 9507285
    Abstract: There are provided ferrite particles in which Mn ferrite is used as the main phase and which contain Sr ferrite, where the degree of projections and recesses in the surface of the particles falls within a range of 2.5 to 4.5 ?m, and the standard deviation of the size of grains appearing on the surface of the particles falls within a range of 1.5 to 3.5 ?m. In this way, a coating resin is left on the surface of the particles even after long-term use and thus a decrease in the charging property is reduced.
    Type: Grant
    Filed: February 26, 2014
    Date of Patent: November 29, 2016
    Assignees: DOWA ELECTRONICS MATERIALS CO., LTD., DOWA IP CREATION CO., LTD.
    Inventors: Takeshi Kawauchi, Shou Ogawa, Yukihiro Matsuda
  • Patent number: 9502603
    Abstract: A method for manufacturing a vertically structured Group III nitride semiconductor LED chip includes a first step of forming a light emitting structure laminate; a second step of forming a plurality of separate light emitting structures by partially removing the light emitting structure laminate to partially expose the growth substrate; a third step of forming a conductive support, which conductive support integrally supporting the light emitting structures; a fourth step of separating the growth substrate by removing the lift-off layer; and a fifth step of dividing the conductive support between the light emitting structures thereby singulating a plurality of LED chips each having the light emitting structure. A first through-hole is formed to open in a central region of each of the light emitting structures such that at least the lift-off layer is exposed, and an etchant is supplied from the first through-hole in the fourth step.
    Type: Grant
    Filed: May 12, 2011
    Date of Patent: November 22, 2016
    Assignees: WAVESQUARE INC., DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Meoung Whan Cho, Seog Woo Lee, Pil Guk Jang, Ryuichi Toba, Yoshitaka Kadowaki
  • Patent number: 9486879
    Abstract: There is provided a bonding material capable of forming a bonding body under an inert gas atmosphere such as a nitrogen atmosphere, and capable of exhibiting a bonding strength that endures a practical use even if not a heat treatment is applied thereto at a high temperature, which is the bonding material containing silver nanoparticles coated with a fatty acid having a carbon number of 8 or less and having an average primary particle size of 1 nm or more and 200 nm or less, and silver particles having an average particle size of 0.5 ?m or more and 10 ?m or less, and an organic material having two or more carboxyl groups.
    Type: Grant
    Filed: May 13, 2011
    Date of Patent: November 8, 2016
    Assignee: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Satoru Kurita, Keiichi Endoh, Yu Saito, Yutaka Hisaeda, Toshihiko Ueyama
  • Publication number: 20160312043
    Abstract: After there is prepared a conductive paste which contains fine copper particles having an average particle diameter of 1 to 100 nm, each of the fine copper particles being coated with an azole compound, coarse copper particles having an average particle diameter of 0.3 to 20 ?m, a glycol solvent, such as ethylene glycol, and at least one of a polyvinylpyrrolidone (PVP) resin and a polyvinyl butyral (PVB) resin and wherein the total amount of the fine copper particles and the coarse copper particles is 50 to 90% by weight, the weight ratio of the fine copper particles to the coarse copper particles being in the range of from 1:9 to 5:5, the conductive paste thus prepared is applied on a substrate by screen printing to be preliminary-fired by vacuum drying, and then, fired with light irradiation by irradiating with light having a wavelength of 200 to 800 nm at a pulse period of 500 to 2000 ?s and a pulse voltage of 1600 to 3800 V to form a conductive film on the substrate.
    Type: Application
    Filed: December 5, 2014
    Publication date: October 27, 2016
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Shuji Kaneda, Hidefumi Fujita, Daisuke Itoh
  • Patent number: 9469916
    Abstract: A method of producing a GaAs single crystal having high carrier concentration and high crystallinity and to provide a GaAs single crystal wafer using such a GaAs single crystal. In the method of producing a GaAs single crystal, a vertical boat method is performed with a crucible receiving a seed crystal, a Si material, a GaAs material serving as an impurity, solid silicon dioxide, and a boron oxide material, thereby growing a GaAs single crystal.
    Type: Grant
    Filed: May 16, 2012
    Date of Patent: October 18, 2016
    Assignee: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Ryoichi Nakamura, Motoichi Murakami, Takehiro Miyaji
  • Publication number: 20160297982
    Abstract: There is produced a fine silver particle dispersing solution which contains: fine silver particles (the content of silver in the fine silver particle dispersing solution is 30 to 90% by weight), which have an average primary particle diameter of 1 to 100 nm and which are coated with an amine having a carbon number of 8 to 12, such as octylamine, serving as an organic protective material; a polar solvent (5 to 70% by weight) having a boiling point of 150 to 300° C.; and an acrylic dispersing agent (1.5 to 5% by weight with respect to the fine silver particles), such as a dispersing agent of at least one of acrylic acid ester and methacrylic acid ester.
    Type: Application
    Filed: December 4, 2014
    Publication date: October 13, 2016
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Takashi Hinotsu, Tomonori Shibayama, Hiromasa Miyoshi
  • Patent number: 9458026
    Abstract: To provide a method for improving a coercive force of epsilon-type iron oxide particles, and an epsilon-type iron oxide. Specifically, to provide a method for improving the coercive force of an epsilon-type iron oxide comprising: substituting Fe-site of the epsilon-type iron oxide with other element, while not substituting Fe of D-site in the epsilon-type iron oxide with other element, and the epsilon type iron oxide.
    Type: Grant
    Filed: September 30, 2010
    Date of Patent: October 4, 2016
    Assignees: THE UNIVERSITY OF TOKYO, DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Shin-ichi Ohkoshi, Shunsuke Sakurai, Asuka Namai, Sayaka Umeda, Hiroshi Hachiya, Kazuyuki Matsumoto, Takashi Gotoh
  • Patent number: 9460850
    Abstract: To provide ferrite magnetic powders for bond magnet capable of surely suppressing residual hexavalent chrome, being an environmental load substance, having no adverse influence on the magnetic characteristics, which is an obstacle in use, and without damaging productivity and at a low cost. The method includes the steps of obtaining sintered powders by sintering raw material powders; wet-pulverizing the sintered powders; wet-cleaning the sintered powders; and annealing the cleaned sintered powders, wherein in the step of the wet-pulverization and in the step of wet-cleaning, generation of the hexavalent chrome, being an environmental load substance, is suppressed by performing the pulverization and cleaning while maintaining pH of a dispersion solvent at 8.5 or less, at the time of pulverization and cleaning.
    Type: Grant
    Filed: April 17, 2014
    Date of Patent: October 4, 2016
    Assignees: DOWA F-TEC CO., LTD., DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Shuichi Kohayashi, Hiroya Ikeda, Hideki Katayama, Keisuke Ayabe
  • Publication number: 20160268477
    Abstract: A long-life III nitride semiconductor light emitting device and a method of producing the same. A III nitride semiconductor light-emitting device includes an n-type semiconductor layer; a light emitting layer containing at least Al; and a p-type semiconductor layer obtained by sequentially stacking an electron blocking layer, a p-type cladding layer, and a p-type contact layer, in this order. The electron blocking layer is made of AlxGa1-xN (0.55?x?1.0), the p-type contact layer is made of AlyGa1-yN (0?y?0.1), the p-type cladding layer is made of AlzGa1-zN having an Al content z which gradually decreases over the whole thickness of the p-type cladding layer from the electron blocking layer side toward the p-type contact layer side, and the reduction rate of the Al content z of the p-type cladding layer in the thickness direction is 0.01/nm or more and 0.025/nm or less.
    Type: Application
    Filed: March 10, 2016
    Publication date: September 15, 2016
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Takehiko FUJITA, Yasuhiro WATANABE
  • Publication number: 20160266510
    Abstract: There are provided ferrite particles that have, as a main component, a material represented by a composition formula MxFe3-xO4 (where M is at least one type of metal selected from a group consisting of Mg, Mn, Ca, Ti, Cu, Zn, Sr and Ni, 0<x<1), where the maximum height Rz of the particles falls within a range of 1.40 to 1.90, and the degree of distortion Rsk of the particles falls within a range of ?0.25 to ?0.07. In this way, when the ferrite particles are used as the carrier of an electrophotographic image forming apparatus, even if an image formation speed is increased, the occurrence of a failure is reduced for a long period of time.
    Type: Application
    Filed: October 29, 2014
    Publication date: September 15, 2016
    Applicants: DOWA ELECTRONICS MATERIALS CO., LTD., DOWA IP CREATION CO., LTD.
    Inventors: Shinya SASAKI, Yohei ISHIKAWA, Haruka SEKI
  • Patent number: D778849
    Type: Grant
    Filed: April 4, 2016
    Date of Patent: February 14, 2017
    Assignee: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventor: Tsukasa Maruyama