Patents by Inventor Akitoshi Hiraki

Akitoshi Hiraki has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5807443
    Abstract: A cold-worked titanium material subjected to isostatic material and a backing plate are brought into contact with each other and subsequently hot-pressing. By such working the titanium material and the backing plate are bonded with each other by mutual diffusion and simultaneously the titanium material is recrystallized. The isostatic pressing is performed under a pressure of 50 to 200 MPa at a temperature of 300.degree. to 450.degree. C. The surface of the titanium material is preferably subjected to a surface roughening treatment to provide with a roughness level of 6S to 12S prior to the isostatic pressing.
    Type: Grant
    Filed: November 27, 1996
    Date of Patent: September 15, 1998
    Assignee: Hitachi Metals, Ltd.
    Inventors: Kaoru Masuda, Shigeru Taniguchi, Akitoshi Hiraki
  • Patent number: 5489367
    Abstract: A target for use in reactive sputtering for forming a film by a reaction with nitrogen, which is a target being composed substantially of titanium and nitrogen and having a nitrogen/titanium atomic ratio, N/Ti, of 0.20 to 0.95, and is used for forming a film whose nitrogen ratio is greater than a ratio of nitrogen to titanium in the target by a reaction with a sputtering gas containing nitrogen, and a method for forming a film, which uses the target.
    Type: Grant
    Filed: August 19, 1994
    Date of Patent: February 6, 1996
    Assignee: Hitachi Metals, Ltd.
    Inventors: Kunichika Kubota, Akitoshi Hiraki
  • Patent number: 5320729
    Abstract: Disclosed herein is a sputtering target with which a high resistivity thin film consisting of chromium, silicon and oxygen can be produced economically and stably for a long time. Also disclosed is a process for producing the sputtering target by selecting the grain size of a chromium (Cr) powder and a silicon dioxide (SiO.sub.2) powder, drying the powders sufficiently by heating, then mixing the dried powders to obtain a mixed powder containing generally from 20 to 80% by weight of chromium, most preferably from 50 to 80% by weight of chromium, the remainder being silicon dioxide, packing the mixed powder in a die, and sintering the packed powder by hot pressing or the like, to produce a desired sputtering target which has a two phase mixed structure. The sputtering target can be used for manufacture of thin film resistors and electric circuits.
    Type: Grant
    Filed: July 17, 1992
    Date of Patent: June 14, 1994
    Assignee: Hitachi, Ltd.
    Inventors: Yasunori Narizuka, Masakazu Ishino, Akihiro Kenmotsu, Yoshitaka Chiba, Akitoshi Hiraki
  • Patent number: 5306569
    Abstract: A titanium-tungsten target material capable of limiting the amount of particles generated during sputtering and a method of manufacturing this titanium-tungsten material. The titanium-tungsten target material has a titanium-tungsten alloy phase which occupies 98% or more of the whole area of the material as observed in a micro-structure thereof. In one example of the manufacturing method, an ingot obtained by melting tungsten and titanium is processde by a solution treatment to form a titanium-tungsten target, or a power obtained by melting the ingot is sintered to form a target. Preferably, the melting may be performed under reduced pressure in an electron beam melting manner. In another example of the manufacturing method, a powder is formed from a molten metal by an atomization method and the obtained powder is sintered to form a titanium-tungsten target. For sintering of the powder, it is preferable to apply hot isostatic pressing or hot pressing.
    Type: Grant
    Filed: July 16, 1992
    Date of Patent: April 26, 1994
    Assignee: Hitachi Metals, Ltd.
    Inventor: Akitoshi Hiraki
  • Patent number: 5298338
    Abstract: A titanium-tungsten target material used to form, by sputtering, a barrier metal or the like for use in semiconductor devices. The titanium-tungsten target material is substantially composed of tungsten particles and a titanium-tungsten alloy phase surrounding the tungsten particles. The area ratio at which tungsten grains occupy in a cross section of the titanium-tungsten target material is, preferably, not more than 15%, more preferably, not more than 10%. If the average crystal grain size of the target material is not more greater 15 .mu.m, a uniform thin film can be obtained by sputtering. The target material can be obtained by sintering a titanium powder and a tungsten powder.
    Type: Grant
    Filed: July 16, 1992
    Date of Patent: March 29, 1994
    Assignee: Hitachi Metals, Ltd.
    Inventor: Akitoshi Hiraki
  • Patent number: 5160534
    Abstract: Ti-W target material for sputtering includes a structure composed of a W phase, a Ti phase, and a Ti-W alloy phase of which 20% or more consist of the area ratio of a micro structure covering the cross section of the Ti-W target material. The Wi-W target material further includes dispersed tungsten particles, the Ti-W alloy phases substantially surrounding the W grains, and the Ti phases dispersed adjacent to the Ti-W alloy phase or the W grains. The formation of the Ti-W alloy phases is capable of reducing a substantial amount of the Ti phase in the target material. It is thus possible to prevent the generation of particles attributable to a difference between sputtering speeds of Ti and Ti-W.
    Type: Grant
    Filed: May 31, 1991
    Date of Patent: November 3, 1992
    Assignee: Hitachi Metals Ltd.
    Inventor: Akitoshi Hiraki
  • Patent number: 4837109
    Abstract: A method of producing a neodymium-iron-boron permanent magnet alloy having a composition of 25.0-50.0 weight % of neodymium, 0.3-5.0 weight % of boron and balance substantially iron, including the steps of adding metal calcium, calcium hydride or a mixture thereof as a reducing agent to neodymium fluoride, iron and boron (or ferroboron), and further adding thereto at least one of calcium chloride, sodium chloride and potassium chloride as a flux, melting the resulting mixture in an inert gas atmosphere, or in a reducing gas atmosphere or substantially in vacuum at 1,000.degree.-1,300.degree. C., thereby reducing said neodymium fluoride to provide said alloy with as small a calcium content as 0.1 weight % or less. The starting materials may contain dysprosium fluoride and niobium to provide Nd-Dy-Fe-B-Nb alloys containing 0.5-15.0 weight % Dy and 0.05-5.0 weight % Nb. This method makes it possible to produce Nd-Fe-B or Nd-Dy-Fe-B-Nb permanent magnet alloys with as small a calcium content as 0.
    Type: Grant
    Filed: July 10, 1987
    Date of Patent: June 6, 1989
    Assignee: Hitachi Metals, Ltd.
    Inventors: Masaaki Tokunaga, Kimio Uchida, Akitoshi Hiraki