Patents by Inventor Junma Nan

Junma Nan 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).

  • Preparation method of diamond-metal sawblades in reactive sintering production for singulating QFN packaging device
    Patent number: 9221153
    Abstract: A method for preparing a sintered metal matrix diamond saw blade used for cutting a QFN packaging device includes steps of: preparing metal matrix by employing metal powder and inorganic filler, wet-mixing and stirring the metal matrix, adding diamond grains to form a mixed material with evenly distributed diamond grains, performing the mixed material through cold pressing for pre-shaping, preparing a sintered metal matrix diamond saw blade blank through hot-pressing sintering, and finally machine-shaping the sintered metal matrix diamond saw blade blank to meet the dimensional requirements. The firm interface metallurgical bond is formed between the metal matrix and the diamond grains by the hot-pressing sintering process, which enhances holding force of the metal matrix on the diamond grains, in such a manner that abrasive grains are not easy to fall off untimely during cutting, thus prolonging service life of the sintered metal matrix diamond saw blade.
    Type: Grant
    Filed: June 10, 2011
    Date of Patent: December 29, 2015
    Assignee: XI' AN JIAOTONG UNIVERSITY
    Inventors: Junma Nan, Kewei Xu
  • Preparation method of diamond-metal sawblades in reactive sintering production for singulating QFN packaging device
    Publication number: 20130205683
    Abstract: A method for preparing a sintered metal matrix diamond saw blade used for cutting a QFN packaging device includes steps of: preparing metal matrix by employing metal powder and inorganic filler, wet-mixing and stirring the metal matrix, adding diamond grains to form a mixed material with evenly distributed diamond grains, performing the mixed material through cold pressing for pre-shaping, preparing a sintered metal matrix diamond saw blade blank through hot-pressing sintering, and finally machine-shaping the sintered metal matrix diamond saw blade blank to meet the dimensional requirements. The firm interface metallurgical bond is formed between the metal matrix and the diamond grains by the hot-pressing sintering process, which enhances holding force of the metal matrix on the diamond grains, in such a manner that abrasive grains are not easy to fall off untimely during cutting, thus prolonging service life of the sintered metal matrix diamond saw blade.
    Type: Application
    Filed: June 10, 2011
    Publication date: August 15, 2013
    Inventors: Junma Nan, Kewei Xu