Abstract: When a substrate having a low heat resistance is used, heat treatment at approximately 120° C. at which deformation does not occur is desirable. When a low resistance is achieved regardless of the type of resin used for a conductive paste, a flexible design of a paste is possible according to purposes, and fields to which the paste could be applied are expanded. Thus, a conductive paste capable of forming a conductive film exhibiting a high conductivity even at low temperatures of approximately 120° C. regardless of whether the constituting resin is a thermosetting resin or a thermoplastic resin is provided. In a method for forming a conductive film, a conductive paste in which a dicarboxylic acid having 2 to 8 carbon atoms is added to a paste including silver nanoparticles coated with an organic substance having 2 to 6 carbon atoms, a dispersion medium, and a resin is used.
Abstract: An object of the present invention is to provide a method for producing a Group III nitride semiconductor epitaxial substrate, a Group III nitride semiconductor element, and a Group III nitride semiconductor free-standing substrate, which have good crystallinity, with not only AlGaN, GaN, and GaInN the growth temperature of which is 1050° C. or less, but also with AlxGa1-xN having a high Al composition, the growth temperature of which is high; a Group III nitride semiconductor growth substrate used for producing these, and a method for efficiently producing those. The present invention provides a Group III nitride semiconductor growth substrate comprising a crystal growth substrate including a surface portion composed of a Group III nitride semiconductor which contains at least Al, and a scandium nitride film formed on the surface portion are provided.
Abstract: Disclosed is a magnetic material having high Hc and High Curie point, which is capable of controlling such magnetic characteristics without requiring rare or expensive raw materials. Specifically disclosed is a magnetic material composed of particles of a magnetic iron oxide which is represented by the following general formula: ?-AxByFe2?x?yO3 or ?-AxByCzFe2?x?y?zO3 (wherein A, B and C each represents a metal excluding Fe and different from each other, satisfying 0<x, y, z<1), with ?-Fe2O3 as a main phase.
Type:
Grant
Filed:
May 30, 2008
Date of Patent:
May 21, 2013
Assignees:
The University of Tokyo, Dowa Electronics Materials Co., Ltd.
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.
Abstract: An epitaxial substrate for electronic devices is provided, which can improve vertical breakdown voltage and provides a method of producing the same. The epitaxial substrate includes a conductive SiC single crystal substrate, a buffer as an insulating layer on the SiC single crystal substrate, and a main laminate formed by epitaxially growing a plurality of Group III nitride layers on the buffer. Further, the buffer includes at least an initial growth layer in contact with the SiC single crystal substrate and a superlattice laminate having a superlattice multi-layer structure on the initial growth layer. The initial growth layer is made of a Ba1Alb1Gac1Ind1N material. Furthermore, the superlattice laminate is configured by alternately stacking a first layer made of a Ba2Alb2Gac2Ind2N material and a second layer made of a Ba3Alb3Gac3Ind3N material having a different band gap from the first layer.
Type:
Grant
Filed:
May 10, 2010
Date of Patent:
April 23, 2013
Assignee:
Dowa Electronics Materials Co., Ltd.
Inventors:
Tetsuya Ikuta, Jo Shimizu, Tomohiko Shibata, Ryo Sakamoto, Tsuneo Ito
Abstract: Provided is a catalyst having the ability to combust PM at relatively low temperatures and having high HC and CO removal (conversion) efficiency even at the above operating temperature. In the catalyst composition, at least one kind of platinum group element selected from Pt, Rh, and Pd is dispersed in and supported by a platinum group-supporting carrier containing at least one kind of element selected from Zr, Al, Y, Si, Bi, Pr, and Tb, and the platinum group-supporting carrier is supported on the surface of a Ce oxide containing Ce as an essential component. The catalyst composition has both PM combustion activity and gas purification activity.
Abstract: Provided is a method for producing a silver fine powder covered with an organic substance, which comprises a step of mixing (i) a dispersion of silver particles covered with a protective material X1 that comprises an organic compound having an unsaturated bond and having a molecular weight of from 150 to 1000 in a liquid organic medium A, (ii) a protective material X2 that comprises an organic compound of which the number of the carbon atoms constituting the carbon skeleton is smaller than that of the organic compound to constitute the protective material X1, and (iii) a liquid organic medium B of which the ability to dissolve the protective material X1 therein is higher than that of the liquid organic medium A, thereby promoting the dissolution of the protective material X1 in the liquid organic medium B and the adhesion of the protective material X2 to the surface of the silver particles.
Type:
Grant
Filed:
May 28, 2008
Date of Patent:
April 16, 2013
Assignees:
Dowa Electronics Materials Co., Ltd., Tokohu University
Abstract: In heteroepitaxially growing a group-III nitride semiconductor on a Si single crystal substrate, the occurrence of cracks initiating in the wafer edge portion can be suppressed. Region A is an outermost peripheral portion outside the principal surface, being a bevel portion tapered. Regions B and C are on the same plane (the principal surface), region B (mirror-surface portion) being the center portion of the principal surface, and region C a region in the principal surface edge portion surrounding region B. The principal surface has a plane orientation, and in region B, is mirror-surface-finished. Region B occupies most of the principal surface of this Si single crystal substrate, and a semiconductor device is manufactured therein. Region C (surface-roughened portion) has a plane orientation as with region B, however, region B is mirror-surface-finished, whereas region C is surface-roughened.
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.
Abstract: An epitaxial substrate for an electronic device having a Si single crystal substrate, a buffer as an insulating layer formed on the Si single crystal substrate, and a main laminated body formed by plural group III nitride layers epitaxially grown on the buffer, wherein a lateral direction of the epitaxial substrate is defined as an electric current conducting direction. The buffer including at least an initially grown layer in contact with the Si single crystal substrate and a superlattice laminate constituted of a superlattice multilayer structure on the initially grown layer.
Type:
Grant
Filed:
December 14, 2009
Date of Patent:
April 2, 2013
Assignee:
Dowa Electronics Materials Co., Ltd.
Inventors:
Tetsuya Ikuta, Jo Shimizu, Tomohiko Shibata
Abstract: A solder layer and an electronic device bonding substrate using the layer are provided which avoid deteriorating qualities of the electronic device to be bonded. In a solder layer 14 free from lead and formed on a substrate 11 or an electronic device bonding substrate 10 having such a solder layer, the solder layer 14 has a specific resistance of not more than 0.4 ?·?m. The electronic device bonding substrate 10 can have a thermal resistance of not more than 0.5 K/W and a thickness of not more than 10 ?m. Then, voids contained in the solder layer 14 have a maximum diameter of not more than 0.5 ?m and the substrate can be a submount substrate.
Abstract: A metal magnetic powder having a metal magnetic phase mainly composed of ferromagnetic elements, and composed of particles containing one or more kinds of elements selected from rare earth elements including Y, and Al, Si. And the method for producing the metal magnetic powder, including the steps of: eluting the non-magnetic components in the particles under an action of a reducing agent acting on the metal magnetic powder, in a solution containing a complexing agent capable of forming the complex with the non-magnetic components; and forming an oxide layer on the particles in the solution after eluting the non-magnetic components into the solution, without drying the particles.
Abstract: A metal magnetic powder for a magnetic recording medium is provided whose particles have a metal magnetic phase, composed mainly of Fe or Fe plus Co, and an oxide layer, wherein the average major axis length of the powder particles is 10-50 nm, the average particle volume including the oxide layer is 5,000 nm3 or less, the atomic ratio (R+Al+Si)/(Fe+Co) calculated using the content values (at. %) of the elements contained in the powder particles is 20% or less, where R is rare earth element (Y being treated as a rare earth element). The metal magnetic powder is obtained by using a complexing agent and a reducing agent to elute nonmagnetic constituents after firing. The metal magnetic powder exhibits a large saturation magnetization as for its particle volume while maintaining weatherability comparable to the conventional level and is suitable for a coated-type magnetic recording medium.
Abstract: A carrier core particle for an electrophotographic developer includes a composition expressed by a general formula: MnxFe3?xO4+y (0<x?1, 0<y), a full width at half maximum z of the most intense peak (311) plane in a powder X-ray diffraction pattern satisfying 0.16 (degree)?z, and a magnetization of 50 emu/g or higher in an external magnetic field of 1000 Oe.
Abstract: A carrier core particle for an electrophotographic developer includes a core composition expressed by a general formula: MnxFe3?xO4+y (0<x?1, 0<y) as a main ingredient, 0.1 wt % or more of Si, and 0.03 wt % or more of at least one metal element selected from the group consisting of Ca, Sr and Mg.
Abstract: To provide a carrier for two-component electrophotographic developer not only having excellent fluidity but also having proper surface irregularities necessary for imparting electric charge, without generating cracks/chipping of particles even under an influence of stirring stress over a long period of time. A particle surface has raised parts of striped pattern extending almost continuously in a plurality of directions while being superposed on one another, with a surface formed with raised parts of striped pattern occupying 80% or more of the whole surface of a particle. Depths of grooves between the adjacent raised parts are 0.05 ?m or more and 0.2 ?m or less, average surface roughness Ra is 0.1 ?m or more and 0.3 ?m or less, roundness is 0.90 or more, and average particle size is 15 ?m or more and 100 ?m or less, and a carrier core material thus constituted is coated with resin. Thus, the carrier for two-component electrophotographic developer is prepared.
Abstract: A semiconductor material is provided comprising: a composition graded layer, formed on a Si substrate or an interlayer formed thereon, comprising a composition of AlXGa1-XN graded such that a content ratio of Al in the composition decreases continuously or discontinuously in a crystal growing direction; a superlattice composite layer, formed on the composition graded layer, comprising a high Al-containing layer comprising a composition of AlYGa1-YN and a low Al-containing layer comprising a composition of AlZGa1-ZN that are laminated alternately; and a nitride semiconductor layer formed on the superlattice composite layer.
Type:
Grant
Filed:
December 17, 2008
Date of Patent:
January 1, 2013
Assignees:
Dowa Electronics Materials Co., Ltd., National University Corporation Nagoya Institute of Technology
Inventors:
Ryo Sakamoto, Jo Shimizu, Tsuneo Ito, Takashi Egawa
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.
Abstract: The present invention provides ferrite powders for bonded magnet capable of suppressing increase of SFD, while widening a particle size distribution for obtaining flowability and compressed density, and also capable of suppressing deterioration of orientation and magnetizability, and provides a process for a production magnetoplumbite-type ferrite powders containing an oxide of at least one or more kinds of transition metals selected from a group consisting of Zr, Ti, Zn, Co, Mn, and Ni, having a mean particle size of 0.20 ?m or more and less than 5.00 ?m, being the ferrite powders for bonded magnet with the ratio of particles having particle size of 1 ?m or less being 20 mass % or more in the magnetoplumbite-type ferrite powder size distribution obtained by a laser diffraction type particle size distribution analyzer.
Abstract: To provide a phosphor for an electron beam excitation with a small deterioration in an emission efficiency and capable of maintaining a high luminance, even when an excitation density of an electron beam for a phosphor excitation is increased. As raw materials, Ca3N2(2N), AlN(3N), Si3N4(3N), and Eu2O3(3N) are prepared, and the raw materials thus prepared are measured and mixed, so that a molar ratio of each element becomes (Ca+Eu):Al:Si=1:1:1. Then, the mixture thus obtained is maintained and fired for at 1500° C. for 3 hours, and thereafter crushed, to manufacture the phosphor having a composition formula Ca0.985SiAlN3:Eu0.015.