Patents Assigned to Dowa Electronics Materials Co., Ltd.
  • FINE SILVER PARTICLE DISPERSION
    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
  • Silver-coated graphite particles, silver-coated graphite mixed powder and production method therefor, and conductive paste
    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
  • Phosphorus-containing copper powder and method for producing the same
    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
  • GROUP III NITRIDE SEMICONDUCTOR LIGHT EMITTING ELEMENT AND METHOD OF MANUFACTURING THE SAME
    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
  • Silver nanowires and method for producing same, and silver nanowire ink and transparent conductive film
    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
  • SILVER POWDER AND METHOD FOR PRODUCING SAME
    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
  • Group III nitride epitaxial substrate and method for manufacturing the same
    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
  • DEEP ULTRAVIOLET LIGHT-EMITTING DEVICE AND METHOD OF MANUFACTURING SAME
    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
  • METHOD OF MANUFACTURING SEMICONDUCTOR OPTICAL DEVICE AND SEMICONDUCTOR OPTICAL DEVICE
    Publication number: 20200227585
    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 on the InP growth substrate; a step of bonding the semiconductor laminate to the support substrate formed from a Si substrate, with at least the metal bonding layer therebetween; and a step of removing the InP growth substrate.
    Type: Application
    Filed: March 27, 2020
    Publication date: July 16, 2020
    Applicant: DOWA Electronics Materials Co., Ltd.
    Inventors: Jumpei YAMAMOTO, Tetsuya IKUTA
  • Carrier core material and electrophotographic development carrier using same and electrophotographic developer
    Patent number: 10698330
    Abstract: A carrier core material formed with ferrite particles, the skewness Rsk of the particle is equal to or more than ?0.40 but equal to or less than ?0.20, and the kurtosis Rku of the particle is equal to or more than 3.20 but equal to or less than 3.50. Here, the maximum height Rz of the particle is equal to or more than 2.20 ?m but equal to or less than 3.50 ?m. Moreover, the ferrite particle contains at least either of Mn and Mg elements. In this way, cracking or chipping in a concave-convex portion of a particle surface is unlikely to occur, and moreover, the amount of coating resin used can be reduced without properties such as electrical resistance being lowered.
    Type: Grant
    Filed: March 28, 2017
    Date of Patent: June 30, 2020
    Assignees: DOWA ELECTRONICS MATERIALS CO., LTD., DOWA IP CREATION CO., LTD.
    Inventors: Yuki Kitahara, Shou Ogawa
  • Oriented body containing e-iron oxide, method for producing the same, and device for producing the same
    Patent number: 10669161
    Abstract: There are provided an oriented body such as a magnetic sheet in which a value of degree of orientation of magnetic particles is beyond 3.5, and a method for producing the same, and a device for producing the same, wherein the oriented body such as a magnetic sheet is produced through the steps of: mixing a mixed solution containing a solvent and a vehicle and ?-iron oxide particles by shaking stirring, and dispersing the ?-iron oxide particles in the mixed solution; providing a mixed solution in which the ?-iron oxide particles are dispersed, on a predetermined substrate; and removing the solvent while applying a magnetic field to the substrate provided with the mixed solution, to obtain an oriented body.
    Type: Grant
    Filed: January 18, 2016
    Date of Patent: June 2, 2020
    Assignees: THE UNIVERSITY OF TOKYO, DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Shin-ichi Ohkoshi, Hiroko Tokoro, Koji Nakabayashi, Asuka Namai, Kenta Imoto, Kenji Masada
  • Ferrite powder for bonded magnets, method for producing the same and ferrite bonded magnet
    Patent number: 10665371
    Abstract: A ferrite powder for bonded magnets having a high iHc value usable even in a low temperature environment, a method for producing the same, and a bonded magnet using the ferrite powder and having high iHc value which can be used even in a low temperature environment, wherein a specific surface area is 2.20 m2/g or more and less than 3.20 m2/g; a compression density is 3.30 g/cm3 or more and less than 3.60 g/cm3, and a compressed molding has a coercive force of 3250 Oe or more and less than 3800 Oe.
    Type: Grant
    Filed: September 30, 2015
    Date of Patent: May 26, 2020
    Assignees: DOWA ELECTRONICS MATERIALS CO., LTD., DOWA F-TEC CO., LTD.
    Inventors: Satoru Tsuboi, Yasunobu Mishima, Keisuke Ayabe, Masayasu Senda
  • Semiconductor optical device and method of manufacturing the same
    Patent number: 10658543
    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: Grant
    Filed: January 30, 2017
    Date of Patent: May 19, 2020
    Assignee: DOWA Electronics Materials Co., Ltd.
    Inventor: Norio Tasaki
  • COPPER POWDER AND METHOD FOR PRODUCING SAME
    Publication number: 20200122236
    Abstract: There are provided an inexpensive copper powder, which has a low content of oxygen even it has a small particle diameter and which has a high shrinkage starting temperature when it is heated, and a method for producing the same. While a molten metal of copper heated to a temperature, which is higher than the melting point of copper by 250 to 700° C. (preferably 350 to 650° C. and more preferably 450 to 600° C.), is allowed to drop, a high-pressure water is sprayed onto the heated molten metal of copper in a non-oxidizing atmosphere (such as an atmosphere of nitrogen, argon, hydrogen or carbon monoxide) to rapidly cool and solidify the heated molten metal of copper to produce a copper powder which has an average particle diameter of 1 to 10 ?m and a crystallite diameter Dx(200) of not less than 40 nm on (200) plane thereof, the content of oxygen in the copper powder being 0.7% by weight or less.
    Type: Application
    Filed: December 21, 2017
    Publication date: April 23, 2020
    Applicant: Dowa Electronics Materials Co., Ltd.
    Inventors: Masahiro Yoshida, Kenichi Inoue, Atsushi Ebara, Yoshiyuki Michiaki, Takahiro Yamada
  • ANTI-REFLECTION FILM AND DEEP ULTRAVIOLET LIGHT-EMITTING DEVICE
    Publication number: 20200124770
    Abstract: Provided is an anti-reflection film having low reflectance even for oblique incidence, which film is highly moisture resistant and is suitable for use in a deep ultraviolet light-emitting device. The anti-reflection film includes: a first layer having a first refractive index, provided on the window member; a second layer having a second refractive index; and a third layer having a third refractive index. For light having a wavelength of 280 nm, the first refractive index is 1.6 or more and 2.0 or less, the second refractive index is 2.0 or more and 2.7 or less and is higher than the first refractive index, the third refractive index is 1.3 or more and 1.6 or less and is lower than the first refractive index, and materials of the layers having the first refractive index, the second refractive index, and the third refractive index are made of oxides different from each other.
    Type: Application
    Filed: December 22, 2017
    Publication date: April 23, 2020
    Applicant: DOWA Electronics Materials Co., Ltd.
    Inventor: Tsukasa MARUYAMA
  • ELECTRICALLY CONDUCTIVE PASTE
    Publication number: 20200118703
    Abstract: There is provided an electrically conductive paste which can prevent the increase of the volume resistivity of an electrically conductive film formed from the electrically conductive paste even if the electrically conductive film is heated to a soldering temperature of about 380° C. when the electrically conductive paste is a resin type electrically conductive paste using a silver powder and a silver-coated copper powder. In an electrically conductive paste containing a resin, a silver powder and a silver-coated copper powder having a copper powder, the surface of which is coated with a silver layer, the resin is an epoxy resin having a naphthalene skeleton, and there is added a dicarboxylic acid, preferably a dicarboxylic acid having a rational formula of HOOC—(CH2)n—COOH (n=1-8), and more preferably a dicarboxylic acid having a rational formula of HOOC—(CH2)n—COOH (n=4-7).
    Type: Application
    Filed: June 27, 2018
    Publication date: April 16, 2020
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Aiko Hirata, Noriaki Nogami
  • Iron-based oxide magnetic particle powder, method for producing same, coating material, and magnetic recording medium
    Patent number: 10622127
    Abstract: An iron-based oxide magnetic particle powder has a narrow particle size distribution a small content of fine particles that do not contribute to magnetic recording characteristics, and a narrow coercive force distribution, to enhance magnetic recording medium density. Neutralizing an aqueous solution containing a trivalent iron ion and an ion of the metal substituting a part of the Fe sites by adding an alkali to make pH of 1.5 or more and 2.5 or less, adding a hydroxycarboxylic acid, and further neutralizing by adding an alkali to make pH of 8.0 or more and 9.0 or less are performed at 5° C. or more and 25° C. or less. A formed iron oxyhydroxide precipitate containing the substituting metal element is rinsed with water, then coated with silicon oxide, and then heated thereby providing e-type iron-based oxide magnetic particle powder. The rinsed precipitate may be subjected to a hydrothermal treatment.
    Type: Grant
    Filed: December 28, 2015
    Date of Patent: April 14, 2020
    Assignee: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Kenji Sakane, Tetsuya Kawahito
  • BONDING MATERIAL AND BONDING METHOD EMPLOYING SAME
    Publication number: 20200094318
    Abstract: The present invention aims at providing a bonding material having both preferable dispensing properties and preferable bonding properties, and also providing a bonding method employing the bonding material. Provided are: a bonding material comprising fine silver particles having an average primary particle diameter of smaller than or equal to 130 nm, and a crosslinking-type inter-particle distance keeping agent crosslinking between the fine silver particles and keeping a distance between the fine silver particles; and a bonding method employing the bonding material.
    Type: Application
    Filed: December 28, 2017
    Publication date: March 26, 2020
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Hideyuki FUJIMOTO, Keiichi ENDOH, Tatsuro HORI, Satoru KURITA
  • Silver-coated copper powder and method for producing same
    Patent number: 10580910
    Abstract: There is provided a silver-coated copper powder which can improve the conversion efficiency of a solar cell in comparison with conventional silver-coated copper powders when it is used in an electrically conductive paste used for forming the busbar electrodes of the solar cell, the silver-coated copper powder being capable of producing a solar cell having a high conversion efficiency which is the same degree as that of a solar cell using silver powder, and a method for producing the same.
    Type: Grant
    Filed: January 26, 2017
    Date of Patent: March 3, 2020
    Assignee: Dowa Electronics Materials Co., Ltd.
    Inventors: Hiroshi Kamiga, Noriaki Nogami, Aiko Hirata
  • Group III nitride semiconductor light-emitting element and method of manufacturing same
    Patent number: 10573783
    Abstract: A group III nitride semiconductor light-emitting element having longer element life than conventional group III nitride semiconductor light-emitting elements and a method of manufacturing the same are provided. A group III nitride semiconductor light-emitting element 100 comprises, in the following order: an n-type group III nitride semiconductor layer 30; a group III nitride semiconductor laminated body 40 obtained by alternately laminating a barrier layer 40a and a well layer 40b narrower in bandgap than the barrier layer 40a in the stated order so that the number of barrier layers 40a and the number of well layers 40b are both N, where N is an integer; an AlN guide layer 60; and a p-type group III nitride semiconductor layer 70, wherein the AlN guide layer 60 has a thickness of 0.5 nm or more and 2.0 nm or less.
    Type: Grant
    Filed: June 22, 2016
    Date of Patent: February 25, 2020
    Assignee: DOWA Electronics Materials Co., Ltd.
    Inventors: Yasuhiro Watanabe, Takehiko Fujita