Patents by Inventor Kunihisa Wada

Kunihisa Wada 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).

  • Bonded substrate, surface acoustic wave chip, and surface acoustic wave device
    Patent number: 7208859
    Abstract: A bonded substrate includes a lithium tantalate substrate and a sapphire substrate to which the lithium tantalate substrate is bonded, a bonded interface of the lithium tantalate and the sapphire substrate includes a bonded region in an amorphous state having a thickness of 0.3 nm to 2.5 nm. The bonded region in the amorphous state is formed by activating at least one of the lithium tantalate substrate and the sapphire substrate in the bonded interface with neutralized atom beams, ion beams or plasma of inert gas or oxygen. It is possible to bond the piezoelectric substrate to the supporting substrate having different lattice constants without the high-temperature thermal treatment and realize the bonded substrate having an excellent bonding strength and being less warped.
    Type: Grant
    Filed: March 2, 2005
    Date of Patent: April 24, 2007
    Assignees: Fujitsu Media Devices Limited, Fujitsu Limited
    Inventors: Michio Miura, Masanori Ueda, Shunichi Aikawa, Toru Uemura, Kunihisa Wada, Naoyuki Mishima
  • Bonded substrate, surface acoustic wave chip, and surface acoustic wave device
    Publication number: 20050194864
    Abstract: A bonded substrate includes a lithium tantalate substrate and a sapphire substrate to which the lithium tantalate substrate is bonded, a bonded interface of the lithium tantalate and the sapphire substrate includes a bonded region in an amorphous state having a thickness of 0.3 nm to 2.5 nm. The bonded region in the amorphous state is formed by activating at least one of the lithium tantalate substrate and the sapphire substrate in the bonded interface with neutralized atom beams, ion beams or plasma of inert gas or oxygen. It is possible to bond the piezoelectric substrate to the supporting substrate having different lattice constants without the high-temperature thermal treatment and realize the bonded substrate having an excellent bonding strength and being less warped.
    Type: Application
    Filed: March 2, 2005
    Publication date: September 8, 2005
    Inventors: Michio Miura, Masanori Ueda, Shunichi Aikawa, Toru Uemura, Kunihisa Wada, Naoyuki Mishima