Patents by Inventor Pai-Hsiang Kao

Pai-Hsiang Kao 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: 6327158
    Abstract: An improved integrated circuit device that includes both bond pads and trim pads is disclosed. Electrically conductive, non-wettable and non-corrosive protective caps are formed over each of the trim pads. With this arrangement, the protective caps act as barriers between the trim pads and solder used to form solder bumps when the IC package is mounted onto a substrate. In one embodiment, the protective caps are formed from a material that is easily sputtered, such as titanium. In a method aspect of the invention, the protective caps are applied during wafer level processing before either the solder bumping or trimming operations.
    Type: Grant
    Filed: January 15, 1999
    Date of Patent: December 4, 2001
    Assignee: National Semiconductor Corporation
    Inventors: Nikhil Vishwanath Kelkar, Pai-Hsiang Kao
  • Patent number: 6249044
    Abstract: A light shield is provided for light sensitive flip chip integrated circuits. The flip chip includes an under bump layer to portions of which solder bumps are attached. A separate portion of this under bump layer is used to provide the light shield. The light shield excludes ambient light from the most light sensitive portions of the circuit so that the electrical characteristics of the flip chip integrated circuit are not significantly altered when the flip chip is operated in ambient light.
    Type: Grant
    Filed: June 17, 1999
    Date of Patent: June 19, 2001
    Assignee: National Semiconductor Corp.
    Inventors: Pai-Hsiang Kao, Nikhil Vishwanath Kelkar
  • Patent number: 6175162
    Abstract: Disclosed is a packaged integrated circuit device. The device includes a die having a plurality of electrical contacts on a first surface of the die and a protective film adhered directly to a back surface of the die, the protective film being thick enough to allow laser marking of the protective film without the laser penetrating to the die. In one preferred embodiment, the protective film of the device is a thick film formed by screen printing. In a preferred embodiment, the protective film has a thickness of between about 1.5 and 5 mils. Also, disclosed is a method of fabricating a semiconductor wafer having a wafer substrate with a top surface and a bottom surface and a plurality of dies. In this embodiment, the method includes providing a plurality of dies on the top surface of the wafer substrate, applying a thick film over the bottom surface of the wafer substrate, adhering the thick film to a mounting tape that is not ultraviolet curable, and dicing the wafer to separate the dies.
    Type: Grant
    Filed: September 8, 1999
    Date of Patent: January 16, 2001
    Assignee: National Semiconductor Corporation
    Inventors: Pai-Hsiang Kao, William Jeffrey Schaefer, Nikhil Vishwanath Kelkar
  • Patent number: 6075290
    Abstract: Disclosed is an IC package. The IC package includes a die having a plurality of conductive pads. A passivation layer is formed over the conductive pads such that the passivation layer has a plurality of passivation vias. Each passivation via is positioned over an associated one of the conductive pads. A resilient protective layer is formed over the passivation layer. The resilient protective layer has a plurality of resilient vias, wherein each resilient via is associated with an associated passivation via. A plurality of under bump pads are in electrical contact with the conductive pads, and each under bump pad is associated with one of the resilient vias. A plurality of contact bumps are formed over the plurality of under bump pads such that each one of the contact bumps is electrically coupled with a selected one of the under bump pads and such that each contact bump is electrically coupled with a selected one of the conductive pads.
    Type: Grant
    Filed: February 26, 1998
    Date of Patent: June 13, 2000
    Assignee: National Semiconductor Corporation
    Inventors: William Jeffrey Schaefer, Pai-Hsiang Kao, Nikhil Vishwanath Kelkar
  • Patent number: 6023094
    Abstract: Disclosed is a packaged integrated circuit device. The device includes a die having a plurality of electrical contacts on a first surface of the die and a protective film adhered directly to a back surface of the die, the protective film being thick enough to allow laser marking of the protective film without the laser penetrating to the die. In one preferred embodiment, the protective film of the device is a thick film formed by screen printing. In a preferred embodiment, the protective film has a thickness of between about 1.5 and 5 mils. Also, disclosed is a method of fabricating a semiconductor wafer having a wafer substrate with a top surface and a bottom surface and a plurality of dies. In this embodiment, the method includes providing a plurality of dies on the top surface of the wafer substrate, applying a thick film over the bottom surface of the wafer substrate, adhering the thick film to a mounting tape that is not ultraviolet curable, and dicing the wafer to separate the dies.
    Type: Grant
    Filed: January 14, 1998
    Date of Patent: February 8, 2000
    Assignee: National Semiconductor Corporation
    Inventors: Pai-Hsiang Kao, William Jeffrey Schaefer, Nikhil Vishwanath Kelkar
  • Patent number: 5923995
    Abstract: Disclosed are methods and apparatuses that allow the dicing of wafers containing microelectromechanical systems into singulated individual dies that is economic to use and leaves substantially no residue on the surface of the individual dies. A method for packaging the dice singulated according to the present invention is also disclosed.
    Type: Grant
    Filed: April 18, 1997
    Date of Patent: July 13, 1999
    Assignee: National Semiconductor Corporation
    Inventors: Pai-Hsiang Kao, Ranjan J. Mathew, Cornelio De Vera
  • Patent number: RE38789
    Abstract: Disclosed is a packaged integrated circuit device. The device includes a die having a plurality of electrical contacts on a first surface of the die and a protective film adhered directly to a back surface of the die, the protective film being thick enough to allow laser marking of the protective film without the laser penetrating to the die. In one preferred embodiment, the protective film of the device is a thick film formed by screen printing. In a preferred embodiment, the protective film has a thickness of between about 1.5 and 5 mils. Also, disclosed is a method of fabricating a semiconductor wafer having a wafer substrate with a top surface and a bottom surface and a plurality of dies. In this embodiment, the method includes providing a plurality of dies on the top surface of the wafer substrate, applying a thick film over the bottom surface of the wafer substrate, adhering the thick film to a mounting tape that is not ultraviolet curable, and dicing the wafer to separate the dies.
    Type: Grant
    Filed: December 17, 2001
    Date of Patent: September 6, 2005
    Assignee: National Semiconductor Corporation
    Inventors: Pai-Hsiang Kao, William Jeffrey Schaefer, Nikhil Vishwanath Kelkar