Patents by Inventor Kei Chun Cheng

Kei Chun Cheng 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).

  • Ultrasonic transducer
    Patent number: 6190497
    Abstract: A bonding tool for applying pressure and ultrasonic energy simultaneously to join miniature components together includes an ultrasonic driver having four composite wafers separated by electrodes. Such bonding tools are known that use wafers made of wholly of ceramic material. By using wafers having four sector parts of ceramic material separated by layers of polymer as shown, bonding tools are provided with broader bandwidth operation and reduced spurious resonance modes.
    Type: Grant
    Filed: April 23, 1999
    Date of Patent: February 20, 2001
    Assignee: The Hong Kong Polytechnic University
    Inventors: Helen Lai Wa Chan, Siu Wing Or, Kei Chun Cheng, Chung Loong Choy