Patents by Inventor Chok J. Chia

Chok J. Chia 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: 5197183
    Abstract: In a leadframe supporting a semiconductor device, the tiebar adjacent the mold gate is kinked, or cut and bent, to form a baffle shielding bond wires connecting the semiconductor device to the leadframe from damage by a jet of incoming molding compound. Whether kinked or cut/bent, the baffle extends out of the plane of the leadframe so as to be disposed more-or-less directly in front of the gate.
    Type: Grant
    Filed: November 5, 1991
    Date of Patent: March 30, 1993
    Assignee: LSI Logic Corporation
    Inventors: Chok J. Chia, Seng-Sooi Lim
  • Patent number: 5185653
    Abstract: A transfer molded plastic package having a cavity for accommodating a semiconductor chip is disclosed. A leadframe assembly process is shown wherein the leadframe finger pattern is provided with a resilient or elastic O-ring bead. Top and bottom housing plates which have dimensions that are larger than the bead form the upper and lower surfaces of the package. These plates can be formed of any suitably rigid material. They may be composed of ceramic in low power devices. For high power operation at least one metal plate can be employed. The chip or chips are connected to the lead frame and, along with the top and bottom plates, is located in a transfer mold. The plates are in registy and located so that their outer edges extend beyond the O-ring bead. The mold cavities include faces which press against the plates which are held apart by the O-ring bead so that the bead is compressed by the mold closure.
    Type: Grant
    Filed: February 28, 1991
    Date of Patent: February 9, 1993
    Assignee: National Semiconductor Corporation
    Inventors: Andrew P. Switky, Chok J. Chia
  • Patent number: 4868349
    Abstract: A molded pin-grid-array package includes a heat sink available at the face opposite to the pins. The heat sink is secured to a printed wiring board that has plated through holes therein that form the desired pin-grip-array and wires are secured in the holes to form the package pins. The heat sink covers an aperture in the board and the semiconductor die is secured to the heat sink inside the cavity thereby formed. After the semiconductor die is attached and the bonding pads connected to the metal traces on the board, the assembly is placed in a transfer mold. Plastic encapsulant is then transfer molded to encapsulate the semiconductor die and to extend flush with the heat sink to form a skirt around the periphery of the board. This leaves the molded package with an available heat sink face for efficient cooling after the package is mounted for ultimate use.
    Type: Grant
    Filed: May 9, 1988
    Date of Patent: September 19, 1989
    Assignee: National Semiconductor Corporation
    Inventor: Chok J. Chia
  • Patent number: 4778641
    Abstract: A pin-grid package is created by starting with printed wiring boards that have plated through holes that can accommodate wire pins. Pins are secured in position to extend outward from one face of the PW board in the form of a pin grid array of the desired configuration which is typically a plurality of concentric rings thereby creating a square grid pattern of predetermined spacing. The opposing PW board face includes a central pin-free area to which is secured a semiconductor die. This face of the PW board includes a plurality of wiring traces that connect each pin to an array that surrounds the semiconductor die. The traces are connected to the bonding pads of the semiconductor die by either wire bonds or a spider assembly using tape assembly bonding. The PW board is located in a mold that has a flat faced first platen that contains cut-out regions that will accommodate the package pins.
    Type: Grant
    Filed: June 18, 1987
    Date of Patent: October 18, 1988
    Assignee: National Semiconductor Corporation
    Inventor: Chok J. Chia
  • Patent number: 4688152
    Abstract: A pin-grid package is created by starting with printed wiring boards that have plated through holes that can accommodate wire pins. Pins are secured in position to extend outward from one face of the PW board in the form of a pin grid array of the desired configuration which is typically a plurality of concentric rings thereby creating a square grid pattern of predetermined spacing. The opposing PW board face includes a central pin-free area to which is secured a semiconductor die. This face of the PW board includes a plurality of wiring traces that connect each pin to an array that surrounds the semiconductor die. The traces are connected to the bonding pads of the semiconductor die by either wire bonds or a spider assembly using tape assembly bonding. The PW board is located in a mold that has a flat faced first platen that contains cut-out regions that will accommodate the package pins.
    Type: Grant
    Filed: August 11, 1986
    Date of Patent: August 18, 1987
    Assignee: National Semiconductor Corporation
    Inventor: Chok J. Chia