Patents Assigned to Dowa Electronics Materials Co., Ltd.
  • Publication number: 20210046549
    Abstract: Provided is a soft magnetic powder capable of forming a powder magnetic core having a high magnetic permeability with a decreased oxygen content even when the particle size is small. There is provided a soft magnetic powder including Fe alloy containing Si which is a soft magnetic powder containing 0.1% to 15 mass % of Si, and having a product of D50 multiplied by [O] (D50×[O]) being 3.0 [?m·mass %] or less, wherein D50 represents a volume-based cumulative 50% particle size [?m] of the soft magnetic powder as measured by a laser diffraction particle size distribution analyzer, and [O] represents an oxygen content [mass %].
    Type: Application
    Filed: September 3, 2018
    Publication date: February 18, 2021
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Masahiro YOSHIDA, Yoshiyuki MICHIAKI, Kenichi INOUE
  • Patent number: 10919778
    Abstract: A method for making iron-based oxide magnetic particle powders having particular peak intensity and diffraction intensities, comprising neutralizing an aqueous solution containing a trivalent iron ion, alone or with a substituting metal (M), a step of adding hydroxycarboxylic acid to the neutralized solution to create a second solution including the hydroxycarboxylic acid D, another neutralizing step for the second solution, a coating step of silicon oxide coating iron oxyhydroxide with or without the substituted metal element found in the second neutralized solution, and heating the coated iron oxyhydroxide with or without the substituted metal element to form a silicon oxide coated iron oxide with or without the substituted metal element. After the second neutralization step, there is no water washing. As a result, the molar ratio D/(Fe+M) is between 0.125 and 1.0 and the silicon oxide coating can be uniform and the formation reaction of the hydroxide is not retarded.
    Type: Grant
    Filed: July 26, 2016
    Date of Patent: February 16, 2021
    Assignee: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Kenji Sakane, Tetsuya Kawahito
  • Patent number: 10915034
    Abstract: A carrier core material is represented by a composition formula MXFe3-XO4 (where M is at least one type of metal element selected from Mg, Mn, Ca, Ti, Cu, Zn and Ni, 0<X<1), in which part of M and/or Fe is substituted with Sr and formed of ferrite particles, and in the carrier core material, a Sr content is equal to or more than 2500 ppm but equal to or less than 12000 ppm, the amount of Sr eluted with pure water at a temperature of 25° C. is equal to or less than 50 ppm, an apparent density is equal to or more than 1.85 g/cm3 but equal to or less than 2.25 g/cm3 and magnetization ?1k when a magnetic field of 79.58×103 A/m (1000 oersteds) is applied is equal to or more than 63 Am2/kg but equal to or less than 75 Am2/kg.
    Type: Grant
    Filed: March 15, 2018
    Date of Patent: February 9, 2021
    Assignees: DOWA ELECTRONICS MATERIALS CO., LTD., DOWA IP CREATION CO., LTD.
    Inventor: Shou Ogawa
  • Patent number: 10903185
    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: Grant
    Filed: May 15, 2015
    Date of Patent: January 26, 2021
    Assignee: Dowa Electronics Materials Co., Ltd.
    Inventors: Keiichi Endoh, Koichi Yuzaki, Minami Nagaoka, Hiromasa Miyoshi, Satoru Kurita
  • Publication number: 20210020814
    Abstract: A method of manufacturing a semiconductor optical device of this disclosure includes the steps of forming an etch stop layer on an InP growth substrate, the etch stop layer having a thickness of 100 nm or less; and forming a semiconductor laminate on the etch stop layer by stacking a plurality of InGaAsP-based III-V group compound semiconductor layers containing at least In and P. Further, an intermediate article of a semiconductor optical device of the present disclosure includes an InP growth substrate; an etch stop layer formed on the InP growth substrate, the etch stop layer having a thickness of 100 nm or less; and a semiconductor laminate formed on the etch stop layer, including a plurality of InGaAsP-based III-V group compound semiconductor layers containing at least In and P stacked one another.
    Type: Application
    Filed: March 27, 2019
    Publication date: January 21, 2021
    Applicant: DOWA Electronics Materials Co., Ltd.
    Inventors: Yuta KOSHIKA, Yoshitaka KADOWAKI, Tetsuya IKUTA
  • Publication number: 20210012936
    Abstract: There is provided a magnetic material that has an excellent electromagnetic wave absorption performance in a wide frequency range even under low temperature and high temperature environments and that ensures the absorption performance, and provided a magnetic material as a mixture of a magnetic material having positive slope of change in coercive force dependent on temperature, and a magnetic material having negative slope of change in coercive force dependent on temperature.
    Type: Application
    Filed: February 14, 2019
    Publication date: January 14, 2021
    Applicants: The University of Tokyo, DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Shin-ichi OHKOSHI, Asuka NAMAI, Marie YOSHIKIYO, Masahiro GOTOH, Toshihiko UEYAMA, Takayuki YOSHIDA
  • Publication number: 20200381589
    Abstract: To provide a bonding-type semiconductor light-emitting device which has excellent reliabilities with smaller time deviations of the light output power and the forward voltage. A semiconductor light-emitting device 100 according to the present disclosure includes a conductive support substrate 80; a metal layer 60 containing a reflective metal provided on the conductive support substrate 10; a semiconductor laminate 30 formed from a stack of a plurality of InGaAsP group III-V compound semiconductor layers containing at least In and P provided on the reflective metal layer 60; an n-type InGaAs contact layer 20A provided on the semiconductor laminate 30; and an n-side electrode 93 provided on the n-type InGaAs contact layer 20A, wherein the center emission wavelength of light emitted from the semiconductor laminate 30 is 1000 to 2200 nm.
    Type: Application
    Filed: December 20, 2018
    Publication date: December 3, 2020
    Applicant: DOWA Electronics Materials Co., Ltd.
    Inventors: Jumpei YAMAMOTO, Tetsuya IKUTA
  • Patent number: 10828702
    Abstract: There is provided a silver powder which has a small average particle diameter and a small thermal shrinkage percentage, and a method for producing the same. While a molten metal of silver heated to a temperature (1292 to 1692° C.), which is higher than the melting point (962° C.) of silver by 330 to 730° C., is allowed to drop, a high-pressure water is sprayed onto the molten metal of silver (preferably at a water pressure of 90 to 160 MPa) to rapidly cool and solidify the molten metal of silver to powderize silver to produce a silver powder which has an average particle diameter of 1 to 6 ?m and a shrinkage percentage of not greater than 8% (preferably not greater than 7%) at 500° C., the product of the average particle diameter by the shrinkage percentage at 500° C. being 1 to 11 ?m·% (preferably 1.5 to 10.5 ?m·%).
    Type: Grant
    Filed: October 26, 2016
    Date of Patent: November 10, 2020
    Assignee: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Atsushi Ebara, Kenichi Inoue, Yoshiyuki Michiaki, Takahiro Yamada, Masahiro Yoshida
  • Patent number: 10833209
    Abstract: A conductive paste including: a conductive powder containing silver; an indium powder; a silver-tellurium-coated glass powder; a solvent; and an organic binder, wherein the silver-tellurium-coated glass powder 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.
    Type: Grant
    Filed: September 5, 2017
    Date of Patent: November 10, 2020
    Assignee: DOWA Electronics Materials Co., Ltd.
    Inventors: Kenichi Harigae, Hiroshi Kamiga, Noriaki Nogami
  • Patent number: 10821558
    Abstract: There is provided an inexpensive bonding material, which can be easily printed on articles to be bonded to each other and which can suppress the generation of voids in the bonded portions of the articles to be bonded to each other, and a bonding method using the same. In a bonding material of a copper paste which contains a copper powder containing 0.3% by weight or less of carbon and having an average particle diameter of 0.1 to 1 ?m, and an alcohol solvent, such as a monoalcohol, a diol, a triol or a terpene alcohol, the content of the copper powder is in the range of from 80% by weight to 95% by weight, and the content of the alcohol solvent is in the range of from 5% by weight to 20% by weight.
    Type: Grant
    Filed: August 31, 2015
    Date of Patent: November 3, 2020
    Assignee: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Keiichi Endoh, Hiromasa Miyoshi, Kimikazu Motomura, Satoru Kurita
  • Patent number: 10807880
    Abstract: An epsilon iron oxide has an average particle size of 10 to 18 nm, a part of the iron element being substituted with a substitutional element and has a coercive force of 14 kOe or less, wherein a coefficient of variation of the particle size is 40% or less. A method for producing the same, a magnetic coating material and a magnetic recording medium using the epsilon iron oxide, includes depositing a metal compound of a substitutional element on iron oxide hydroxide to thereby obtain iron oxide hydroxide on which the metal compound is deposited; coating the iron oxide hydroxide on which the metal compound is deposited, with silicon oxide to thereby obtain iron oxide hydroxide coated with the silicon oxide; and applying heat treatment to the silicon oxide-coated iron oxide hydroxide in an oxidizing atmosphere, wherein a part of an iron element is substituted with the substitutional element.
    Type: Grant
    Filed: June 13, 2016
    Date of Patent: October 20, 2020
    Assignees: THE UNIVERSITY OF TOKYO, DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Shin-ichi Ohkoshi, Syunsuke Oka, Asuka Namai, Kenji Masada
  • Patent number: 10807161
    Abstract: A silver powder, wherein the silver powder satisfies D50-IPA>D50-W, where in measurement of a volume-based particle size distribution of the silver powder by a laser diffraction particle size distribution analysis, D50-IPA (?m) is a cumulative 50% point of particle diameter of the silver powder when isopropyl alcohol (IPA) is used as a measurement solvent for dispersing the silver powder, and D50-W (?m) is a cumulative 50% point of particle diameter of the silver powder when water is used as a measurement solvent for dispersing the silver powder, and wherein a phosphorus content in the silver powder is 0.01% by mass or more but 0.3% by mass or less.
    Type: Grant
    Filed: March 11, 2019
    Date of Patent: October 20, 2020
    Assignee: DOWA Electronics Materials Co., Ltd.
    Inventors: Naoki Tahara, Noriaki Nogami, Hiroshi Kamiga
  • Publication number: 20200321139
    Abstract: This disclosure relates to a fine silver particle dispersion including: (1) 65 to 95.4% by weight of fine silver particles which have an average primary particle diameter of 10 to 190 nm and which comprise 25% by number or less of silver particles having a primary particle diameter of 100 nm or larger, (2) 4.5 to 34.5% by weight of a solvent, and (3) 0.1 to 1.0% by weight of ethyl cellulose having a weight average molecular weight of 10,000 to 120,000.
    Type: Application
    Filed: April 4, 2019
    Publication date: October 8, 2020
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Shingo TERAGAWA, Takashi HINOTSU, Dave HUI, Michael Stephen WOLFE, Howard David GLICKSMAN, Haixin YANG
  • Patent number: 10773311
    Abstract: An object of the present invention is to provide a phosphorus-containing copper powder with good volume resistivity and a small carbon content by suppressing an oxygen content to a relatively low value even if a particle size is made small, and a method for producing the same. In the phosphorus-containing copper powder containing phosphorus, a ratio of an oxygen content (wt. %) to a BET specific surface area (m2/g) (oxygen content/BET specific surface area) is 0.90 wt. %·g/m2 or less, a divalent copper compound is present on a surface of particles constituting the phosphorus-containing copper powder, a carbon content is 0.10 wt. % or less, and D50 is 7.11 ?m or less.
    Type: Grant
    Filed: August 18, 2016
    Date of Patent: September 15, 2020
    Assignee: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Kenichi Inoue, Atsushi Ebara, Masahiro Yoshida, Kyoso Masuda, Takahiro Yamada, Shinichi Uchiyama
  • Patent number: 10773961
    Abstract: To provide a silver-coated graphite mixed powder including: silver-coated graphite particles each including a graphite particle and silver coated on a surface of the graphite particle, where when a solution obtained by dissolving the silver-coated graphite mixed powder in nitric acid is analyzed through inductively coupled plasma (ICP) emission spectrometry, an amount of silver is 5% by mass or more but 90% by mass or less, an amount of tin is 0.01% by mass or more but 5% by mass or less, and an amount of zinc is 0.002% by mass or more but 1% by mass or less.
    Type: Grant
    Filed: December 6, 2016
    Date of Patent: September 15, 2020
    Assignee: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Kairi Otani, Noriaki Nogami, Yoshio Moteki, Taku Okano
  • Publication number: 20200287087
    Abstract: Provided are a group III nitride semiconductor light emitting element and a method of manufacturing the same. A group III nitride semiconductor light emitting element of the present disclosure comprises in this order, in a substrate, an n-type semiconductor layer, a light emitting layer, a p-type electron blocking layer, a p-type contact layer made of AlxGa1-xN, and a p-side reflection electrode, wherein a center emission wavelength of light emitted from the light emitting layer is 270 nm or greater and 330 nm or smaller, the p-type contact layer is in contact with the p-side reflection electrode, and has a thickness of 20 nm or greater and 80 nm or smaller, and the Al composition ratio x of the p-type contact layer satisfies the following Formula: 2.09?0.006×?p?x?2.25?0.006×?p where ?p is the center emission wavelength in nanometer.
    Type: Application
    Filed: March 23, 2018
    Publication date: September 10, 2020
    Applicant: DOWA Electronics Materials Co., Ltd.
    Inventor: Yasuhiro WATANABE
  • Patent number: 10758977
    Abstract: To provide thin and long silver nanowires covered with an organic protective agent containing a less amount of impurities, the silver nanowires having good dispersibility in an ink having an alcohol added thereto. Silver nanowires containing covered thereon a copolymer composition containing one or more kinds of a copolymer having a vinylpyrrolidone structural unit, and having a sulfur content Sppm of 2,000 ppm or less and a residual vinylpyrrolidone monomer content ratio VPR obtained from an NMR spectrum of 6.0% or less, the silver nanowires having an average diameter of 30 nm or less and an average length of 10 ?m or more.
    Type: Grant
    Filed: June 1, 2017
    Date of Patent: September 1, 2020
    Assignee: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Hirotoshi Saito, Kimitaka Sato
  • Publication number: 20200238388
    Abstract: A silver powder which has a small content of carbon and which is difficult to be agglutinated, and a method for producing the same. While a molten metal, which is prepared by melting silver to which 40 ppm or more of copper is added, is allowed to drop, a high-pressure water is sprayed onto the molten metal to rapidly cool and solidify the molten metal to produce a silver powder which contains 40 ppm or more of copper, 0.1% by weight or less of carbon and 0.
    Type: Application
    Filed: September 18, 2018
    Publication date: July 30, 2020
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Yoshiyuki Michiaki, Masahiro Yoshida, Kenichi Inoue
  • Patent number: 10727303
    Abstract: Provided is a Group III nitride epitaxial substrate that can suppress the occurrence of breakage during a device formation process and a method for manufacturing the same. A Group III nitride epitaxial substrate according to the present invention includes a Si substrate, an initial layer in contact with the Si substrate, and a superlattice laminate, formed on the initial layer, including a plurality of sets of laminates, each of the laminates including, in order, a first layer made of AlGaN with an Al composition ratio greater than 0.5 and 1 or less and a second layer made of AlGaN with an Al composition ratio greater than 0 and 0.5 or less. The Al composition ratio of the second layer progressively decreases with distance from the substrate.
    Type: Grant
    Filed: July 11, 2012
    Date of Patent: July 28, 2020
    Assignee: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Tetsuya Ikuta, Tomohiko Shibata
  • Publication number: 20200235260
    Abstract: Disclosed is a deep ultraviolet light-emitting device which includes on a substrate 10 in order: an n-type semiconductor layer 30, a light-emitting layer 40, a p-type electron block layer 60, and a p-type contact layer 70, wherein the p-type contact layer 70 comprises a superlattice structure having an alternating stack of: a first layer 71 made of AlxGa1-xN having an Al composition ratio x higher than an Al composition ratio w0 of a layer configured to emit deep ultraviolet light in the light-emitting layer; and a second layer 72 made of AlyGa1-yN having an Al composition ratio y lower than the Al composition ratio x, and the Al composition ratio w0, the Al composition ratio x, the Al composition ratio y, and a thickness average Al composition ratio z of the p-type contact layer satisfy the formula [1] 0.030<z?w0<0.20 and the formula [2] 0.050?x?y?0.47.
    Type: Application
    Filed: September 28, 2018
    Publication date: July 23, 2020
    Applicant: DOWA Electronics Materials Co., Ltd.
    Inventor: Yasuhiro WATANABE