Patents by Inventor Hirozoh Tsuruta

Hirozoh Tsuruta 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: 7306508
    Abstract: A multi-wire saw according to the present invention cuts a workpiece while supplying a slurry containing an alkali or mixed acid to a cutting interface between the workpiece and a wire, and includes: a storage tank with a heating mechanism for storing and heating the slurry; a thermal insulating pipe for transporting the slurry sent with a pump from the storage tank with a heating mechanism to a position before a position where the wire is incorporated into the workpiece, while keeping the slurry at a predetermined temperature; a thermostat for keeping a temperature in a vicinity of the workpiece fixed to a stage at the predetermined temperature; and a wire heating mechanism for heating the wire to the predetermined temperature. Consequently, the cutting resistance decreases during cutting machining of a silicon ingot, and the variation in the cutting resistance also decreases, whereby a high-quality wafer can be obtained at a high efficiency and a low cost.
    Type: Grant
    Filed: October 22, 2004
    Date of Patent: December 11, 2007
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takafumi Kawasaki, Hirozoh Tsuruta, Hirokazu Nishida, Seiichi Mimura, Masayuki Hamayasu, Hisashi Tominaga
  • Publication number: 20060249134
    Abstract: A multi-wire saw according to the present invention cuts a workpiece while supplying a slurry containing an alkali or mixed acid to a cutting interface between the workpiece and a wire, and includes: a storage tank with a heating mechanism for storing and heating the slurry; a thermal insulating pipe for transporting the slurry sent with a pump from the storage tank with a heating mechanism to a position before a position where the wire is incorporated into the workpiece, while keeping the slurry at a predetermined temperature; a thermostat for keeping a temperature in a vicinity of the workpiece fixed to a stage at the predetermined temperature; and a wire heating mechanism for heating the wire to the predetermined temperature. Consequently, the cutting resistance decreases during cutting machining of a silicon ingot, and the variation in the cutting resistance also decreases, whereby a high-quality wafer can be obtained at a high efficiency and a low cost.
    Type: Application
    Filed: October 22, 2004
    Publication date: November 9, 2006
    Inventors: Takafumi Kawasaki, Hirozoh Tsuruta, Hirokazu Nishida, Seiichi Mimura, Masayuki Hamayasu, Hisashi Tominaga
  • Publication number: 20060075687
    Abstract: In a slurry for cutting a silicon ingot according to the present invention, a content of a basic material is at least 3.5% by mass with respect to the total mass of a liquid component of a slurry, organic amine is contained in a mass ratio of 0.5 to 5.0 with respect to water in a liquid component of the slurry, and pH of the slurry is 12 or more. Furthermore, according to a method of cutting a silicon ingot according to the present invention, the above-mentioned slurry for cutting a silicon ingot is used at 65° C. to 95° C. Consequently, the cutting resistance during cutting processing of a silicon ingot is reduced, and a wafer of high quality can be obtained efficiently.
    Type: Application
    Filed: October 12, 2004
    Publication date: April 13, 2006
    Inventors: Hirozoh Tsuruta, Masayuki Hamayasu, Takafumi Kawasaki, Hirokazu Nishida, Hisashi Tominaga