Patents Assigned to Dowa Mining Co., Ltd.
  • Publication number: 20060045832
    Abstract: In order to provide a phosphor mixture which contains four or more kinds of phosphors comprising a red phosphor, an orange phosphor, a blue phosphor, and a green phosphor, and produce emission having excellent color rendering not only in the case of white light at a high color temperature, but also in the case of emission in warm white which is low in color temperature, and a light emitting device including the phosphor mixture and a light-emitting section, CaAlSiN3:Eu and CaAl2Si4N8:Eu are manufactured as a red phosphor and an orange phosphor respectively, and ZnS:Cu, Al, and BAM:Eu are prepared as a green phosphor and a blue phosphor respectively.
    Type: Application
    Filed: November 10, 2004
    Publication date: March 2, 2006
    Applicant: Dowa Mining Co., Ltd.
    Inventors: Akira Nagatomi, Masahiro Gotoh, Kenji Sakane
  • Publication number: 20060033083
    Abstract: To provide a phosphor having an emission characteristic such that a peak wavelength of light emission is in a range from 580 to 680 nm, and having a high emission intensity, and having a flat excitation band with high efficiency for excitation light in a broad wavelength range from ultraviolet to visible light (wavelength range from 250 nm to 550 nm). For example, Ca3N2(2N), AlN(3N), Si3N4(3N), Eu2O3(3N) are prepared, and after weighing and mixing a predetermined amount of each raw material, raw materials are fired at 1500° C. for 6 hours, thus obtaining the phosphor including a product phase expressed by a composition formula CaAlSiN3:Eu and having an X-ray diffraction pattern satisfying a predetermined pattern.
    Type: Application
    Filed: July 15, 2005
    Publication date: February 16, 2006
    Applicant: DOWA MINING CO., LTD.
    Inventors: Kenji Sakane, Akira Nagatomi, Masahiro Gotoh, Shuji Yamashita
  • Patent number: 6998700
    Abstract: There is provided a notched compound semiconductor crystal having the same specification even if it is turned over. With respect to a compound semiconductor wafer produced by slicing a compound semiconductor crystal having a crystal plane of (100) plane, the crystal is sliced so as to be tilted from the (100) plane in a direction of [101] or [10?1] when a notch is formed in a direction of [010], or the crystal is sliced so as to be tilted from the (100) plane in a direction of [0?10] or [010] when a notch is formed in a direction of [001], or the crystal is sliced so as to be tilted from the (100) plane in a direction of [001] or [00?1] when a notch is formed in a direction of [0?10], or the crystal is sliced so as to be tilted from the (100) plane in a direction of [010] or [0?10] when a notch is formed in a direction of [00?1].
    Type: Grant
    Filed: June 10, 2002
    Date of Patent: February 14, 2006
    Assignee: Dowa Mining Co., LTD
    Inventors: Ryuichi Toba, Naoya Sunachi
  • Patent number: 6997233
    Abstract: To provide a mold capable of manufacturing a metal-ceramic composite member in which a predetermined number of ceramic members are joined onto a large joining metal, the large joining metal being free from swell and shrinkage cavity on the surface thereof and high in dimensional precision. A metal-ceramic composite member 3 according to this embodiment is manufactured in such a manner that a predetermined number of metal-ceramic bonded substrates 30 are placed in a mold main body 11 constituting a mold 1, with a ceramic substrate 31 side thereof facing upward, an atmosphere inside and outside the mold 1 is replaced with an inert gas such as a nitrogen gas from the atmosphere, a molten metal 42 is poured and filled in a first joining portion 14 that is formed by the molten metal main body 11 and an upper container 13 and that has a shrinkage cavity inducing portion 16 on a metal material holding portion side and a shrinkage cavity inducing portion 18 on an air vent side, and the molten metal 42 is cooled.
    Type: Grant
    Filed: September 24, 2003
    Date of Patent: February 14, 2006
    Assignee: Dowa Mining Co., Ltd.
    Inventors: Hideyo Osanai, Susumu Ibaragi, Makoto Namioka
  • Patent number: 6994756
    Abstract: A method of producing a sintered rare earth magnetic alloy wafer comprises a step of using a cutter to slice a wafer of a thickness of not greater than 3 mm from a sintered rare earth magnetic alloy having ferromagnetic crystal grains surrounded by a more readily grindable grain boundary phase and a step of surface-grinding at least one cut surface of the obtained wafer with a grindstone to form at a surface layer thereof flat ferromagnetic crystal grain cross-sections lying parallel to the wafer planar surface. The method enables high-yield production of a sintered rare earth magnetic alloy wafer having flat surfaces.
    Type: Grant
    Filed: November 22, 2002
    Date of Patent: February 7, 2006
    Assignee: Dowa Mining Co., Ltd.
    Inventors: Kiyoshi Yamada, Hirofumi Takei, Masami Kamada, Toshinori Eba
  • Publication number: 20060022573
    Abstract: A phosphor, which has less reduction in emission efficiency and is capable of keeping high luminance even when density of an electron beam for exciting the phosphor increases, is provided. As raw materials, Ca3N2 (2N), AlN (3N), Si3N4 (3N), and Eu2O3 (3N) are prepared, and each of the raw materials is weighed so that a mole ratio of each element is, for example, (Ca+Eu):Al:Si=1:1:1, and mixed, then the mixture is held and fired at 1500° C. under the inert atmosphere for three hours, and thereafter ground to produce a phosphor having a composition formula of Ca0.985SiAlN3:Eu0.
    Type: Application
    Filed: September 27, 2004
    Publication date: February 2, 2006
    Applicant: DOWA MINING CO., LTD.
    Inventors: Masahiro Gotoh, Akira Nagatomi, Kenji Sakane, Shuji Yamashita
  • Publication number: 20060021788
    Abstract: To provide a composite conductor suitable as a connecting conductor capable of reducing generation of Joule heat in a joint part between a conductor on a system side and a conductor on a power-supply side, while using a superconductor with less thermal invasion to a superconductive apparatus system. A composite conductor 10 comprises a superconductor 12 provided continuously in the flowing direction of the electric current, and a metal conductor 11 joined with the superconductor 12 and provided at least at a joint part with mating conductors 50, 60 to be joined, wherein the electric current is fed and received between the metal conductor 11 and the mating conductors 50, 60 by joining the metal conductor 11 and the mating conductors 50, 60, and wherein the superconductor 12 is arranged in the metal conductor 11 so as to be approximately parallel to the joint surface (joint interface) between the metal conductor 11 and the mating conductors 50, 60.
    Type: Application
    Filed: November 24, 2004
    Publication date: February 2, 2006
    Applicants: DOWA MINING CO., LTD., CHUBU ELECTRIC POWER CO., INC.
    Inventors: Shuichi Kohayashi, Kazuyuki Uemura, Shigeo Nagaya, Naoji Kashima
  • Publication number: 20060017365
    Abstract: A phosphor of which emission wavelength can be optionally set in a region with high human visual sensitivity to make it possible to enhance lumlinance in the region, and which has an excitation band for light in a wavelength region emitted from the aforesaid light emitting portion, a production method of the same, illumination and an LED using the aforesaid phosphor are provided. As raw materials, for example, Ca3N2, CaO, Al2O3, AlN, Si3N4, and SiO2 an Eu2O3 are prepared, and each of the raw material is weighed so that a mole ratio of each element is, for example, (Ca, Eu): Al: Si=1:1:1, mixed and prepared under a nitrogen atmosphere, fired at 1500° C.
    Type: Application
    Filed: August 20, 2004
    Publication date: January 26, 2006
    Applicant: DOWA MINING CO., LTD.
    Inventors: Akira Nagatomi, Masahiro Gotoh, Kenji Sakane, Shuji Yamashita
  • Publication number: 20060011934
    Abstract: An improvement in electrode reliability is realized by preventing over-etching on a peripheral lower portion of an electrode while maintaining the flow of steps of roughening a surface after forming the electrode on a semiconductor substrate. After a P-side electrode 4 is formed on a main surface 3a of a semiconductor substrate 3, a surface of the P-side electrode 4 is selectively covered with a protective film 12, after the semiconductor substrate 3 is cut into chips, the surface is roughened from above the protective film 12, the main surface 3a around the P-side electrode 4 and a side surface are roughened with a non-chemical treatment region 10 which is a non-roughened surface region being left in a peripheral portion of the P-side electrode 4 covered with the protective film 12, and thereafter the protective film 12 is removed.
    Type: Application
    Filed: March 30, 2004
    Publication date: January 19, 2006
    Applicant: DOWA MINING CO., LTD.
    Inventors: Naoya Sunachi, Hiroyuki Matsuoka
  • Publication number: 20060006782
    Abstract: A phosphor having an excitation band relative to lights in the wide range of wavelengths from ultraviolet to visible light, and having an emission spectrum in the red range and so on, with a wide half value width, and an LED and a light source using the phosphor and emitting white and other color lights with good color rendering properties are provided. Powdered raw materials of Ca3N2 (2N), CaO (2N), AlN (3N), Si3N4 (3N), and Eu2O3 (3N) are prepared, and the respective raw materials are mixed to have a mole ratio of the respective elements of Ca:Al:Si:Eu=0.985:1:1:0.015. The mixed raw materials are fired at 1000° C. or higher in an inert atmosphere for three hours, and thereafter pulverized to obtain a phosphor having a composition of CaAlSiN2.83O0.25:Eu, which is one example of the phosphor satisfying the above described object.
    Type: Application
    Filed: September 2, 2004
    Publication date: January 12, 2006
    Applicant: DOWA MINING CO., LTD.
    Inventors: Akira Nagatomi, Masahiro Gotoh, Kenji Sakane, Shuji Yamashita
  • Publication number: 20050267243
    Abstract: A metal paste, in which a filler mainly composed of metal is mixed with good dispersibility, is manufactured with good productivity at a low cost without generating a foil of the metal. A paste-like material (referred to as a paste material hereafter) containing a metal filler is fed into a gap between a pair of rotating whetstones 11 and 12 which are relatively rotated while facing with each other having a specified gap therebetween, to pass and discharge therein. The paste material is thus kneaded and dispersed. In addition, the paste material is kneaded and dispersed by suppressing the generation of a metal foil, adjusting the gap to a specified interval dg and feeding the paste material into the interval while applying thereon a predetermined positive pressure and/or negative pressure.
    Type: Application
    Filed: May 26, 2005
    Publication date: December 1, 2005
    Applicant: DOWA MINING CO., LTD.
    Inventors: Kazuyoshi Amasaki, Shuichi Kohayashi, Yoshikazu Omoto
  • Publication number: 20050253500
    Abstract: A phosphor with high efficiency having an excitation band corresponding to light of the ultraviolet-visible (300 to 550 nm) wavelength region emitted from a light emitting element which emits blue or ultraviolet light is provided. Commercially available CaO [3N], Si3N4 [3N], and Eu2O3 [3N] are prepared, respective materials are weighed and mixed to have a mol ratio of CaO:Si3N4:Eu2O3=1.4775:1:0.01125, and then the mixture is heated to 1600° C. by a heating rate of 15° C./min under a nitrogen atmosphere and retained and fired at 1600° C. for three hours. Thereafter, the raw materials are cooled down from 1600° C. to 200° C. for an hour to thereby produce a phosphor having a composition formula Ca1.58Si3O1.63N4.35:Eu0.024.
    Type: Application
    Filed: August 20, 2004
    Publication date: November 17, 2005
    Applicant: DOWA MINING CO., LTD.
    Inventors: Masahiro Gotoh, Akira Nagatomi, Kenji Sakane, Shuji Yamashita
  • Patent number: 6949150
    Abstract: Copper alloy having the basic composition Cu—Zn—Sn contains 23-28 wt % Zn and 0.3-1.8 wt % Sn and satisfies the relation 6.0?0.25X+Y?8.5 (where X is the addition of Zn in wt % and Y is the addition of Sn in wt %). The alloy is cast into an ingot by melting and cooling over the range from the liquidus line to 600° C. at a rate of at least 50° C./min; the ingot is hot rolled at a temperature not higher than 900° C. and then subjected to repeated cycles of cold rolling and annealing at 300-650° C. to control the size of crystal grains, thereby producing a rolled strip having a 0.2% yield strength of at least 600 N/mm2, a tensile strength of at least 650 N/mm2, an electrical conductivity of at least 20% IACS, a Young's modulus of no more than 120 kN/mm2 and a percent stress relaxation of no more than 20%.
    Type: Grant
    Filed: September 23, 2002
    Date of Patent: September 27, 2005
    Assignee: Dowa Mining Co., Ltd.
    Inventors: Akira Sugawara, Kazuki Hatakeyama, Le Ling
  • Patent number: 6942742
    Abstract: A copper-based alloy excellent in dezincing resistance comprises, in percentage by weight, Cu: 57-69%, Sn: 0.3-3%, Si: 0.02-1.5%, Bi: 0.5-3%, and Pb: not more than 0.2%, where the ratio of Si/Sn expressed in weight percentage is in the range of 0.05-1 and apparent zinc content as defined by the following formula is in the range of more than 39-50 wt. %, and the balance of unavoidable impurities: Apparent Zn content=[(Zn %+2.0×Sn %+10.0×Si %)/(Cu %+Zn %+2.0×Sn %+10.0×Si %)]×100. Despite the fact that contains no added environment-unfriendly Pb, the alloy exhibits enhanced cuttability, together with excellent forgeability, dezincing resistance and hot forgeability.
    Type: Grant
    Filed: October 29, 2003
    Date of Patent: September 13, 2005
    Assignee: Dowa Mining Co., Ltd.
    Inventor: Yoshinori Yamagishi
  • Patent number: 6938333
    Abstract: A metal-ceramic circuit board is characterized by being constituted by bonding on a base plate of aluminum or aluminum alloy at least one of ceramic substrate boards having a conductive metal member for an electronic circuit. A method of manufacturing a metal-ceramic circuit board is characterized by comprising the steps of melting aluminum or aluminum alloy in a vacuum or inert gas atmosphere to form a molten metal, contacting one surface of a ceramic substrate board directly with the molten metal in a vacuum or inert gas atmosphere, cooling the molten metal and the ceramic substrate board to form a base plate of aluminum or aluminum alloy, which is bonded directly on the ceramic substrate board without forming any oxidizing film therebetween and bonding a conductive metal member for an electronic circuit on the ceramic substrate board by using a brazing material. The base plate has a proof stress not higher than 320 (MPa) and a thickness not smaller than 1 mm.
    Type: Grant
    Filed: September 12, 2002
    Date of Patent: September 6, 2005
    Assignee: Dowa Mining Co., Ltd.
    Inventors: Hideyo Osanai, Masahiro Furo
  • Publication number: 20050189863
    Abstract: A phosphor with high efficiency having an excitation band corresponding to light of the ultraviolet-visible (300 to 550 nm) wavelength region emitted from a light emitting portion which emits blue or ultraviolet light is provided. A nitride of Ca, a nitride of Al, a nitride QfSi, and an oxide of Eu are prepared, and respective raw materials are weighed so that a mol ratio of respective elements becomes Ca:Al:Si:Eu=0.985:3:1:0.015, mixed under a nitrogen atmosphere, and thereafter fired at 1500° C. in a nitrogen atmosphere to thereby produce a phosphor having a composition formula Ca0.985SiAlN3:Eu0.015.
    Type: Application
    Filed: August 20, 2004
    Publication date: September 1, 2005
    Applicant: DOWA MINING CO., LTD.
    Inventors: Akira Nagatomi, Kenji Sakane, Masahiro Gotoh, Shuji Yamashita
  • Patent number: 6936337
    Abstract: There is provided a metal/ceramic circuit board capable of eliminating discrepancy during mounting of parts to improve the reliability of mounting of the parts. The metal/ceramic circuit board has a ceramic substrate 10, and a metal circuit plate (a copper plate 14) bonded to the ceramic substrate 10, the metal circuit plate having a thickness which is more than 0.25 mm and which is less than 0.3 mm, and the metal circuit plate having a skirt spreading length (a dimensional difference between the bottom and top portion of the peripheral edge portion of the metal circuit plate) of less than 50 ?m.
    Type: Grant
    Filed: November 14, 2003
    Date of Patent: August 30, 2005
    Assignee: Dowa Mining Co., Ltd.
    Inventors: Nobuyoshi Tsukaguchi, Masami Kimura
  • Patent number: 6935554
    Abstract: There is provided a method for producing a metal/ceramic bonding article, the method including the steps of: arranging a metal plate 12 of an overall-rate solid solution type alloy on a ceramic substrate 10; and heating the metal plate 12 and the ceramic substrate 10 in a non-oxidizing atmosphere at a temperature of lower than a melting point of the alloy to bond the metal plate 12 directly to the ceramic substrate 10. According to this method, it is possible to easily bond an alloy plate directly to a ceramic substrate, and it is possible to inexpensively provide an electronic member for resistance without causing the alloy plate to be deteriorated.
    Type: Grant
    Filed: September 25, 2002
    Date of Patent: August 30, 2005
    Assignee: Dowa Mining, Co. Ltd.
    Inventors: Masami Kimura, Susumu Shimada
  • Patent number: 6932852
    Abstract: A 99.99% pure indium feed is charged into a crucible and heated to 1250 ° C. by an upper heater in a vacuum atmosphere at 1×10?4 Torr, whereupon indium evaporates, condenses on the inner surfaces of an inner tube and drips to be recovered into a liquid reservoir in the lower part of a tubular member, whereas impurity elements having a lower vapor pressure than indium stay within the crucible. The recovered indium mass in the liquid reservoir is heated to 1100° C. by a lower heater and the resulting vapors of impurity elements having a higher vapor pressure than indium pass through diffuser plates in an upper part of the tubular member to be discharged from the system, whereas the indium vapor recondenses upon contact with the diffuser plates and returns to the liquid reservoir, yielding 99.9999% pure indium, while preventing the loss of indium.
    Type: Grant
    Filed: July 2, 2003
    Date of Patent: August 23, 2005
    Assignee: Dowa Mining Co., Ltd.
    Inventors: Kishio Tayama, Toshiaki Hodozuka
  • Patent number: 6926999
    Abstract: A cathode active material for alkaline electrochemical cells comprising an Ag—Bi-M-containing oxidation product produced by oxidizing with an oxidizing agent an Ag—Bi-M-containing neutralized precipitate obtained by reacting inorganic acid salts of silver, bismuth and, optionally, M (M representing at least one metal selected from the group comprised of manganese, nickel and cobalt) with an alkali hydroxide in an aqueous medium; or comprising an Ag—Bi-M-containing oxidation product obtained by reacting inorganic acid salts of silver, bismuth and, optionally, M with an alkali hydroxide in an aqueous medium and in the presence of an oxidizer.
    Type: Grant
    Filed: September 10, 2001
    Date of Patent: August 9, 2005
    Assignee: Dowa Mining Co., Ltd.
    Inventors: Koji Tanoue, Yoshikazu Omoto, Yoshiyuki Shoji, Masayuki Nishina, Toshio Ueda