Patents Assigned to Dowa Electronics Materials Co., Ltd.
  • Publication number: 20140166943
    Abstract: A p-AlGaN layer doped with magnesium is provided that includes an aluminum composition ratio x of 0.2 or more and less than 0.5 and a carrier concentration of 2.5×1017/cm3 or more. A Group III nitride semiconductor light emitting device including the p-AlxGa1-xN layer is also provided.
    Type: Application
    Filed: February 20, 2014
    Publication date: June 19, 2014
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Yoshikazu OOSHIKA, Tetsuya MATSUURA
  • Patent number: 8747579
    Abstract: A solder layer and an electronic device bonding substrate having high bonding strength of a device and low bonding failure even by a simplified bonding method of a device to a substrate and a method for manufacturing the same are provided. A device bonding substrate 1 including a substrate 2 and a lead free solder layer 5 formed on said substrate has a solder layer 5 consisting of a plurality of layers having mutually different phases, and oxygen concentration on the upper surface of the solder layer is lower than 30 atomic % of the concentration of the metal component which is the most oxidizable among the metal components making up the upper layer of the solder layer 5. Carbon concentration on the upper surface of the solder layer 5 may be lower than 10 atomic % of the concentration of the metal component which is the most oxidizable among the metal components making up the upper layer of the solder layer.
    Type: Grant
    Filed: February 27, 2008
    Date of Patent: June 10, 2014
    Assignee: Dowa Electronics Materials Co., Ltd.
    Inventors: Yoshikazu Oshika, Munenori Hashimoto, Masayuki Nakano
  • Publication number: 20140154623
    Abstract: The carrier core particles for electrophotographic developer include a core composition expressed by a general formula Fe3O4 as a main ingredient and 30 ppm to 400 ppm Na. Such carrier core particles can reduce environmental dependency thereof, while optimizing the resistivity.
    Type: Application
    Filed: February 7, 2014
    Publication date: June 5, 2014
    Applicants: DOWA IP CREATION CO., LTD., DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventor: Takeshi KAWAUCHI
  • Patent number: 8742396
    Abstract: A III nitride epitaxial substrate which makes it possible to obtain a deep ultraviolet light emitting device with improved light output power is provided. A III nitride epitaxial substrate includes a substrate, an AlN buffer layer, a first superlattice laminate, a second superlattice laminate and a III nitride laminate in this order. The III nitride laminate includes an active layer including an Al?Ga1-?N (0.03??) layer. The first superlattice laminate includes AlaGa1-aN layers and AlbGa1-bN (0.9<b?1) layers which are alternately stacked, where ?(alpha)<a and a<b. The second superlattice laminate includes repeated layer sets each having an AlxGa1-xN layer, an AlyGa1-yN layer, and an AlzGa1-zN (0.9<z?1) layer, where ?(alpha)<x and x<y<z.
    Type: Grant
    Filed: January 11, 2013
    Date of Patent: June 3, 2014
    Assignee: Dowa Electronics Materials Co., Ltd.
    Inventor: Yoshikazu Ooshika
  • Patent number: 8735938
    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: Grant
    Filed: July 2, 2013
    Date of Patent: May 27, 2014
    Assignee: Dowa Electronics Materials Co., Ltd.
    Inventors: Yoshikazu Ooshika, Tetsuya Matsuura
  • Publication number: 20140120359
    Abstract: [OBJECT] A composition of a metal nanoparticle is provided in which reproducibility in a method of producing a metal film with excellent low-temperature sinterable properties is improved. An article using the metal nanoparticle composition is also provided. [SOLVING MEANS] A composition of a metal nanoparticle that has a secondary aggregation diameter (median diameter) of 2.0 ?m or less as determined by disk centrifugal-type particle size measurement is used.
    Type: Application
    Filed: March 17, 2011
    Publication date: May 1, 2014
    Applicant: DOWA Electronics Materials Co., Ltd.
    Inventors: Gregory A JABLONSKI, Michael A MASTROPIETRO, Kimitaka SATO, Satoru KURITA, Hidefumi FUJITA
  • Patent number: 8710489
    Abstract: To provide an epitaxial substrate for electronic devices, in which current flows in a lateral direction, which enables accurate measurement of the sheet resistance of HEMTs without contact, and to provide a method of efficiently producing the epitaxial substrate for electronic devices, the method characteristically includes the steps of forming a barrier layer against impurity diffusion on one surface of a high-resistance Si-single crystal substrate, forming a buffer as an insulating layer on the other surface of the high-resistance Si-single crystal substrate, producing an epitaxial substrate by epitaxially growing a plurality of III-nitride layers on the buffer to form a main laminate, and measuring resistance of the main laminate of the epitaxial substrate without contact.
    Type: Grant
    Filed: July 13, 2010
    Date of Patent: April 29, 2014
    Assignee: Dowa Electronics Materials Co., Ltd.
    Inventors: Tetsuya Ikuta, Daisuke Hino, Ryo Sakamoto, Tomohiko Shibata
  • Publication number: 20140113109
    Abstract: A bonding material using silver nanoparticles considerably changes in coating-material property in response to a slight change in composition, and the stability thereof has been insufficient for large-amount application. A bonding material which uses silver nanoparticles, meets the requirements for mass printing, attains dimensional stability, and gives a smooth printed surface is provided. The bonding material includes silver nanoparticles which have at least an average primary particle diameter of 1 nm to 200 nm and have been coated with an organic substance having 8 or less carbon atoms, a dispersion medium, and a viscosity modifier composed of an organic substance, and has a viscosity (measured at a shear rate of 15.7 [1/s]) of 100 Pa·s or lower and a thixotropic ratio (measured at a shear rate of 3.1 [1/s]/measured at a shear rate of 15.7 [1/s]) of 4 or lower.
    Type: Application
    Filed: June 10, 2011
    Publication date: April 24, 2014
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Satoru Kurita, Takashi Hinotsu, Shinya Sasaki
  • Patent number: 8680509
    Abstract: A nitride semiconductor device is provided, in which a superlattice strain buffer layer using AlGaN layers having a low Al content or GaN layers is formed with good flatness, and a nitride semiconductor layer with good flatness and crystallinity is formed on the superlattice strain buffer layer. A nitride semiconductor device includes a substrate; an AlN strain buffer layer made of AlN formed on the substrate; a superlattice strain buffer layer formed on the AlN strain buffer layer; and a nitride semiconductor layer formed on the superlattice strain buffer layer, and is characterized in that the superlattice strain buffer layer has a superlattice structure formed by alternately stacking first layers made of AlxGa1-xN (0?x?0.25), which further contain p-type impurity, and second layers made of AlN.
    Type: Grant
    Filed: August 23, 2010
    Date of Patent: March 25, 2014
    Assignee: Dowa Electronics Materials Co., Ltd.
    Inventors: Yoshikazu Ooshika, Tetsuya Matsuura
  • Patent number: 8673049
    Abstract: A silver nanoparticle composition is provided which is possible to be sintered through sintering at a low temperature in a short time and to form silver electro conductive film and wiring which is favorable for adhesion to a substrate and low in resistance, and articles using the same are provided. The silver nanoparticle composition is provided, wherein a main component of a solvent is water, a pH of the composition is within a range of 5.3 to 8.0, a silver nanoparticle included in the composition is protected by an organic acid or a derivative thereof, and the content of the organic acid or the derivative thereof with respect to silver is 2 to 20% by mass.
    Type: Grant
    Filed: August 27, 2010
    Date of Patent: March 18, 2014
    Assignees: DOWA Electronics Materials Co., Ltd., PChem Associates, Inc.
    Inventors: Gregory A. Jablonski, Michael A. Mastropietro, Kimitaka Sato, Hiromasa Miyoshi, Hidefumi Fujita
  • Patent number: 8652736
    Abstract: The present invention provides a carrier core material for use in the production of an electrophotographic developer which, even when applied, for example, to MFPs (multifunction printers), can realize stable, high-quality and high-speed development, and has a prolonged replacing life of magnetic carriers, and a method of manufacturing the same, a magnetic carrier including the carrier core material, and an electrophotographic developer manufactured from the magnetic carrier. An electrophotographic development carrier is prepared by adding resin particles, a binder, a dispersant, a wetting agent, and water to a raw material powder, wet pulverizing the mixture, drying the pulverized product to give granulated powder, calcinatng the granulated powder, and then sintering the granulated powder to prepare a carrier core material having an internally hollow structure, and coating the carrier core material with a resin.
    Type: Grant
    Filed: September 25, 2006
    Date of Patent: February 18, 2014
    Assignees: Dowa IP Creation Co., Ltd., Dowa Electronics Materials Co., Ltd.
    Inventors: Ryusuke Nakao, Takeshi Kawauchi
  • Patent number: 8641929
    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: Grant
    Filed: June 10, 2011
    Date of Patent: February 4, 2014
    Assignee: Dowa Electronics Materials Co., Ltd.
    Inventors: Keiichi Endoh, Yutaka Hisaeda, Akihiro Miyazawa, Aiko Nagahara, Toshihiko Ueyama
  • Publication number: 20140015105
    Abstract: The purpose of the present invention is to provide a good ohmic contact for an n-type Group-III nitride semiconductor. An n-type GaN layer and a p-type GaN layer are aequentially formed on a lift-off layer (growth step). A p-side electrode is formed on the top face of the p-type GaN layer. A copper block is formed over the entire area of the top face through a cap metal. Then, the lift-off layer is removed by making a chemical treatment (lift-off step). Then, a laminate structure constituted by the n-type GaN layer, with which the surface of the N polar plane has been exposed, and the p-type GaN layer is subjected to anisotropic wet etching (surface etching step). The N-polar surface after the etching has irregularities constituted by {10-1-1} planes. Then, an n-side electrode is formed on the bottom face of the n-type GaN layer (electrode formation step).
    Type: Application
    Filed: December 28, 2010
    Publication date: January 16, 2014
    Applicants: WAVESQUARE INC., DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Ryuichi Toba, Yoshitaka Kadowaki, Meoung Whan Cho, Seog Woo Lee, Pil Guk Jang
  • Publication number: 20140017609
    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: Application
    Filed: March 2, 2012
    Publication date: January 16, 2014
    Applicants: DOWA IP CREATION CO., LTD., DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Takeshi Kawauchi, Tomohide IIda
  • Publication number: 20140017606
    Abstract: A material expressed as a composition formula MXFe3-XO4 (where M is at least one of Mg and Mn, and 0?X?1) is a main component, and as a total amount, 0.1 to 2.5 weight percent of at least one of a Sr element and a Ca element is contained. Here, when ferrite particles are used as a carrier, in terms of obtaining a higher image density, the fluidity of the ferrite particles magnetized under a magnetic field of 1000/(4?) kA/m (1000 oersteds) is preferably 40 seconds or more. The residual magnetization ?r is preferably 3 Am2/kg or more.
    Type: Application
    Filed: March 19, 2012
    Publication date: January 16, 2014
    Applicants: DOWA IP CREATION CO., LTD, DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Tomoya Yamada, Tomohide Iida
  • Patent number: 8629078
    Abstract: To provide an oxidation catalyst capable of burning PM of diesel engine exhausts gas at a low temperature, and hardly subjected to poisoning due to sulfur oxide. A composite oxide contains Ce, Bi, and M (wherein M is one or more elements selected from Mg, Ca, Sr, and Ba) and oxygen, and is manufactured, with a molar ratio of Ce, Bi, M expressed by Ce:Bi:M=(1?x?y):x:y, satisfying 0<x?0.4, and 0<y?0.4. This composite oxide is suitable as a PM combustion catalyst, and is hardly subjected to poisoning due to sulfur oxide.
    Type: Grant
    Filed: October 12, 2007
    Date of Patent: January 14, 2014
    Assignee: Dowa Electronics Materials Co., Ltd.
    Inventors: Yuki Kaneshiro, Takuya Yano, Akira Nagatomi
  • Publication number: 20140001508
    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: Application
    Filed: March 9, 2012
    Publication date: January 2, 2014
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Norio Tasaki, Hidetaka Yamada, Hiroyuki Togawa
  • Publication number: 20140001511
    Abstract: A method for manufacturing vertically structured Group III nitride semiconductor LED chips includes a step of forming a light emitting laminate on a growth substrate; a step of forming a plurality of separate light emitting structures by partially removing the light emitting laminate to partially expose the growth substrate; a step of forming a conductive support on the plurality of light emitting structures; a step of lifting off the growth substrate from the plurality of light emitting structures; and a step of cutting the conductive support thereby singulating a plurality of LED chips each having the light emitting structure. The step of partially removing the light emitting laminate is performed such that each of the plurality of light emitting structures has a top view shape of a circle or a 4n-gon (“n” is a positive integer) having rounded corners.
    Type: Application
    Filed: September 4, 2013
    Publication date: January 2, 2014
    Applicants: DOWA ELECTRONICS MATERIALS CO., LTD., WAVESQUARE INC.
    Inventors: Meoung Whan CHO, Seog Woo LEE, Pil Guk JANG, Ryuichi TOBA, Tatsunori TOYOTA, Yoshitaka KADOWAKI
  • Patent number: D703862
    Type: Grant
    Filed: March 27, 2013
    Date of Patent: April 29, 2014
    Assignees: Wavesquare Inc., Dowa Electronics Materials Co., Ltd.
    Inventors: Meoung Whan Cho, Seog Woo Lee, Ryuichi Toba, Yoshitaka Kadowaki
  • Patent number: D703863
    Type: Grant
    Filed: March 27, 2013
    Date of Patent: April 29, 2014
    Assignees: Wavesquare Inc., Dowa Electronics Materials Co., Ltd.
    Inventors: Meoung Whan Cho, Seog Woo Lee, Ryuichi Toba, Yoshitaka Kadowaki