Patents Assigned to Dowa Electronics Materials Co., Ltd.
  • Publication number: 20240399454
    Abstract: Provided are a silver powder that when used as a conductive paste, has low tendency to experience disconnection even with reduced line width and has lower volume resistivity than is conventionally the case, a conductive paste containing such a silver powder as a conductive filler, and a method of producing such a silver powder. The silver powder is a collection of silver particles that has an apparent density of not less than 8.2 g/cm3 and not more than 9.2 g/cm3 and a value of not less than 1.1 and not more than 1.4 for a ratio of length of a perimeter in a particle cross-section for the silver particles and length of a line circumscribing a periphery of the particle cross-section.
    Type: Application
    Filed: September 27, 2022
    Publication date: December 5, 2024
    Applicant: DOWA Electronics Materials Co., Ltd.
    Inventors: Masanori FUJII, Tetsu TAKAHASHI, Koji HIRATA, Taro NAKANOYA
  • Publication number: 20240392475
    Abstract: Provided is a GaAs wafer having suppressed carrier concentration and low dislocation density, as well as a large proportion of the area of a region with zero dislocation density to the GaAs wafer surface. The GaAs wafer has a silicon concentration of 1.0×1017 cm?3 or more and less than 1.1×1018 cm?3; an indium concentration of 3.0×1018 cm?3 or more and less than 3.0×1019 cm?3; a boron concentration of 2.5×1018 cm?3 or more; a carrier concentration of 1.0×1016 cm?3 or more and 4.0×1017 cm?3 or less; and a proportion of the area of a region with zero dislocation density to the wafer surface of 91.0% or more.
    Type: Application
    Filed: September 22, 2022
    Publication date: November 28, 2024
    Applicant: DOWA Electronics Materials Co., Ltd.
    Inventors: Naoya SUNACHI, Ryuichi TOBA, Akira AKAISHI
  • Publication number: 20240375179
    Abstract: Provided are a silver powder that is suitable as a conductive filler for a conductive paste that enables low-temperature firing and a method of producing this silver powder. The method of producing a silver powder includes an azole addition step of adding an azole to a silver ammine complex aqueous solution to obtain a first liquid, a reductant addition step of adding a reductant to the first liquid to obtain a second liquid, and a fatty acid addition step of adding a fatty acid to the second liquid to obtain a third liquid. The fatty acid is an unsaturated fatty acid including two or more double bonds.
    Type: Application
    Filed: September 14, 2022
    Publication date: November 14, 2024
    Applicant: DOWA Electronics Materials Co., Ltd.
    Inventor: Satoko SUGAWARA
  • Patent number: 12125702
    Abstract: Provided is a semiconductor light-emitting element that exhibits a light emission spectrum in which a single peak is obtained by controlling multi peaks. In the semiconductor light-emitting element having a second conductivity type cladding layer on the light extraction side, the arithmetic mean roughness Ra of a surface of the light extraction surface of the second conductivity type cladding layer is 0.07 ?m or more and 0.7 ?m or less, and the skewness Rsk of the surface is a positive value.
    Type: Grant
    Filed: October 13, 2020
    Date of Patent: October 22, 2024
    Assignee: DOWA Electronics Materials Co., Ltd.
    Inventors: Osamu Tanaka, Yoshitaka Kadowaki
  • Patent number: 12121965
    Abstract: A silicon oxide-coated soft magnetic powder, in which the ratio of a volume-based cumulative 50% particle diameter D50 (HE) according to a dry laser diffraction particle size distribution analysis to the same particle diameter D50 (MT) according to a wet laser diffraction particle size distribution analysis is 0.7 or more, and a coverage ratio R defined by R=Si×100/(Si+M) (Si and M are molar fractions of Si and elements constituting the soft magnetic powder) is 70% or more is obtained by subjecting a slurry containing a soft magnetic powder containing 20 mass % or more of iron and a hydrolysate of a silicon alkoxide to a dispersion treatment when the surface of the soft magnetic powder is coated with the hydrolysate in a mixed solvent of water and an organic substance. The powder has good insulation/dispersibility properties and a high filling factor during molding.
    Type: Grant
    Filed: November 19, 2020
    Date of Patent: October 22, 2024
    Assignee: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Hidefumi Fujita, Koji Tanoue, Keisuke Yamada, Tetsuya Kawahito
  • Patent number: 12113155
    Abstract: The method of manufacturing an optical semiconductor device includes: a mounting step of placing an optical semiconductor chip on a package substrate made of ceramic; a storing step of storing the package substrate after the mounting step in a first dry atmosphere; a placing step of subjecting the optical semiconductor chip on the package substrate to a second dry atmosphere and placing a light transparent window on a joint portion of the package substrate with a joint material therebetween; and a sealing step of joining the joint portion and the light transparent window with the joint material in a low oxygen concentration atmosphere having an oxygen concentration of 1 vol % or less, thereby encapsulating the optical semiconductor chip in a confined space formed by the package substrate and the light transparent window.
    Type: Grant
    Filed: September 18, 2020
    Date of Patent: October 8, 2024
    Assignee: DOWA Electronics Materials Co., Ltd.
    Inventors: Tsukasa Maruyama, Takashi Araki, Takehiro Miyaji
  • Patent number: 12107199
    Abstract: Provided is a light-emitting element lamp capable of increasing a light extraction efficiency and its manufacturing method. The light-emitting element lamp according to the present invention includes: a light-emitting element having a semiconductor layer provided on a substrate; a first lens of spherical segment shape provided by protruding from a surface on the opposite side of the semiconductor layer of the substrate and having a spherical cap that includes a bottom surface consisting of an attaching surface to the surface and a protruding surface from the surface and a radius of curvature R1; and a second lens attached to the side of the light-emitting element and the protruding surface of the first lens, in which the second lens has a concave curve from a peripheral side of the bottom surface of the first lens to the semiconductor layer side on the side of the light-emitting element.
    Type: Grant
    Filed: July 10, 2020
    Date of Patent: October 1, 2024
    Assignee: DOWA Electronics Materials Co., Ltd.
    Inventors: Tsukasa Maruyama, Takashi Araki
  • Patent number: 12095004
    Abstract: The point source light-emitting diode includes a substrate; an n-type cladding layer; a light emitting layer; a p-type cladding layer; an n-type current confinement layer; a p-type contact layer provided on the n-type current confinement layer; and a p-type electrode having a light emission window concentric with the opening. The window opening width of the light emission window is equal to or larger than an opening width of the opening. The point source light-emitting diode has a hydrogen ion implanted area extending from the p-type contact layer to the light emitting layer in the thickness direction. The light emitting layer has a non-implanted region that has a region width larger than the opening width of the light emission window and is concentric with the light emission window, and a hydrogen ion implanted region enclosing the non-implanted region.
    Type: Grant
    Filed: October 1, 2020
    Date of Patent: September 17, 2024
    Assignee: DOWA Electronics Materials Co., Ltd.
    Inventors: Masatoshi Iwata, Naruki Shindo
  • Publication number: 20240266552
    Abstract: In a perovskite-type composite oxide powder according to the present invention, the geometric standard deviation value of the maximum Feret diameter of the perovskite-type composite oxide powder calculated by performing image analysis on an SEM image acquired with a scanning electron microscope is equal to or greater than 1.01 and less than 1.60, and when it is assumed that the perovskite-type composite oxide powder is spherical, the ratio (B/A) of an area value B directly calculated by the image analysis to an area value A calculated from the maximum Feret diameter is equal to or greater than 0.7 and less than 1.0. In this way, the perovskite-type composite oxide powder is used as the air electrode material of an SOFC, and thus high conductivity as compared with a conventional air electrode material is obtained.
    Type: Application
    Filed: September 6, 2022
    Publication date: August 8, 2024
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Toshihiko UEYAMA, Kazumasa IKARI, Shintaro OGAWA
  • Patent number: 12057260
    Abstract: A silicon oxide-coated iron powder has a small particle diameter, can achieve high in a high frequency band, and has high insulating property. In a method for producing the powder, a silicon alkoxide is added to a slurry containing iron powder having an average particle diameter of 0.25 ?m or more and 0.80 ?m or less and an average axial ratio of 1.5 or less dispersed in a mixed solvent of water and an organic material containing water in an amount of 1% by mass or more and 40% by mass or less. Then, a hydrolysis catalyst for the silicon alkoxide is added to perform silicon oxide coating, the method resulting in a silicon oxide-coated iron powder having the high ?? in a high frequency band and the high insulating property.
    Type: Grant
    Filed: January 11, 2019
    Date of Patent: August 6, 2024
    Assignee: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Daisuke Kodama, Masahiro Gotoh
  • Patent number: 12051523
    Abstract: Provided is silver powder including silver particles having closed pores inside the particles, wherein when cross sections of the silver particles are observed at a magnification of 10,000, an average of numbers of the pores having Heywood diameters of 200 nm or greater relative to an area of the cross sections is 0.01 pores/?m2 or less, and wherein when the cross sections of the silver particles are observed at a magnification of 40,000, an average of numbers of the pores having Heywood diameters of 10 nm or greater but less than 30 nm relative to the area of the cross sections is 25 pores/?m2 or more.
    Type: Grant
    Filed: August 16, 2023
    Date of Patent: July 30, 2024
    Assignee: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Masanori Fujii, Yuma Higashi
  • Patent number: 12048964
    Abstract: In a bonding material of a metal paste containing metal particles, a solvent and a dispersant, the metal particles containing first metal particles having an average primary particle diameter of 1 to 40 nm, second metal particles having an average primary particle diameter of 41 to 110 nm, and third metal particles having an average primary particle diameter of 120 nm to 10 ?m, the weight percentages of the first, second and third metal particles being 1.4 to 49% by weight, 36% by weight or less, and 50 to 95% by weight, respectively, with respect to the total 100% by weight of the metal particles, and the weight ratio of the first metal particles to the second metal particles being 14/36 or more.
    Type: Grant
    Filed: September 27, 2017
    Date of Patent: July 30, 2024
    Assignee: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventors: Keiichi Endoh, Minami Kanasugi, Hideyuki Fujimoto, Satoru Kurita
  • Patent number: 12049684
    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: Grant
    Filed: May 12, 2023
    Date of Patent: July 30, 2024
    Assignee: Dowa Electronics Materials Co., Ltd.
    Inventors: Masahiro Yoshida, Kenichi Inoue, Atsushi Ebara, Yoshiyuki Michiaki, Takahiro Yamada
  • Publication number: 20240227002
    Abstract: Provided are a silver powder having powder physical properties enabling reduction of volume resistivity after firing and a method of producing this silver powder. The silver powder has a tap density of 4.8 g/mL or more, a TAP/D50 value (value determined by dividing the tap density (g/mL) by the volume-based median diameter (?m)) of not less than 7 and not more than 15, and a specific surface area of not less than 0.75 m2/g and not more than 1.3 m2/g.
    Type: Application
    Filed: March 2, 2022
    Publication date: July 11, 2024
    Applicant: DOWA Electronics Materials Co., Ltd.
    Inventors: Kaori TOKUSADA, Hikaru HAYASHIDA
  • Publication number: 20240234625
    Abstract: A light-emitting element having high emission output power and light emission efficiency and a method of manufacturing of the same are provided. A light-emitting element according to the present disclosure includes an n-type semiconductor layer; an InAsSbP active layer containing at least In and As on the n-type semiconductor layer; a p-type semiconductor layer that is lattice-matched with the InAsSbP active layer, on the InAsSbP active layer; and a p-type InGaAs window layer that is lattice-mismatched with the p-type semiconductor layer, on the p-type semiconductor layer, wherein the p-type semiconductor layer has a thickness of 20 nm or more and 520 nm or less.
    Type: Application
    Filed: January 4, 2024
    Publication date: July 11, 2024
    Applicant: DOWA Electronics Materials Co., Ltd.
    Inventors: Shiori SASAKI, Yoshitaka KADOWAKI
  • Publication number: 20240201612
    Abstract: A carrier core material includes ferrite particles, contains CaSiO3, and has a true density at least equal to 3.5 g/cm3 and at most equal to 4.5 g/cm3. A particle strength index calculated from formula (1) is preferably at most equal to 1.5% by volume. (1): Particle strength index=V2?V1 (In the formula, V1: cumulative value (% by volume) of particle size 22 ?m or less in cumulative particle size distribution of carrier core material before crushing test, and V2: cumulative value (% by volume) of particle size 22 ?m or less in cumulative particle size distribution of carrier core material after crushing test) Crushing test conditions: 30 g of carrier core material crushed using a sample mill for 60 seconds at a rotational speed of 14000 rpm.
    Type: Application
    Filed: April 19, 2022
    Publication date: June 20, 2024
    Applicants: DOWA ELECTRONICS MATERIALS CO., LTD., DOWA IP CREATION CO., LTD.
    Inventor: Shinya SASAKI
  • Patent number: 11996496
    Abstract: A semiconductor light-emitting device includes: a conductive support substrate; a metal layer comprising a reflective metal provided on the conductive support substrate; a semiconductor laminate provided on the metal layer, the semiconductor laminate being a stack of a plurality of InGaAsP-based III-V group compound semiconductor layers containing at least In and P; an n-type InGaAs contact layer provided on the semiconductor laminate; and an n-side electrode provided on the n-type InGaAs contact layer. A center emission wavelength of light emitted from the semiconductor laminate is 1000 to 2200 nm.
    Type: Grant
    Filed: November 8, 2022
    Date of Patent: May 28, 2024
    Assignee: DOWA Electronics Materials Co., Ltd.
    Inventors: Jumpei Yamamoto, Tetsuya Ikuta
  • Publication number: 20240162031
    Abstract: A method of producing a GaAs wafer having excellent OF orientation stability even in a GaAs wafer having an off angle, and a GaAs wafer group are provided. A method of producing a GaAs wafer includes: a grinding step of grinding a peripheral surface of a GaAs ingot including formation of a provisional orientation flat; a slicing step of slicing the GaAs ingot after the grinding step to cut out a material wafer having an off angle; and a cleaving step of applying marking to the material wafer according to an orientation of an orientation flat determined based on the provisional orientation flat and cleaving the material wafer toward a peripheral surface of the material wafer from the marking to form the orientation flat.
    Type: Application
    Filed: March 17, 2022
    Publication date: May 16, 2024
    Applicant: DOWA Electronics Materials Co., Ltd.
    Inventor: Junji SUGIURA
  • Publication number: 20240157436
    Abstract: To provide a flaky silver powder having a tapped density of from 0.8 g/mL to 1.9 g/mL, and a cumulative 50th percentile particle diameter (D50) of from 2 ?m to 7 ?m, where the cumulative 50th percentile particle diameter (D50) is measured by laser diffraction or laser scattering particle size analysis.
    Type: Application
    Filed: March 1, 2022
    Publication date: May 16, 2024
    Applicant: DOWA ELECTRONICS MATERIALS CO., LTD.
    Inventor: Takuya KOJIMA
  • Patent number: 11984535
    Abstract: Provided is a III-nitride semiconductor light-emitting device having excellent light output power as compared with conventional devices and a method of producing the same. The III-nitride semiconductor light-emitting device has an emission wavelength of 200 nm to 350 nm and includes an n-type semiconductor layer; a light emitting layer in which N barrier layers 40b and N well layers 40w (where N is an integer) are alternately stacked in this order; an AlN guide layer; an electron blocking layer; and a p-type semiconductor layer in this order. The electron block layer is made of p-type AlzGa1-zN (0.50?z?0.80), and the barrier layers are made of n-type AlbGa1-bN (z+0.01?b?0.95).
    Type: Grant
    Filed: October 31, 2019
    Date of Patent: May 14, 2024
    Assignee: DOWA Electronics Materials Co., Ltd.
    Inventor: Yasuhiro Watanabe