Patents by Inventor William M. Loh

William M. Loh 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: 8258016
    Abstract: Embodiments of the invention include a semiconductor integrated circuit package that includes a substrate having an integrated circuit die attached thereto. The package includes a ESD shield attached to the substrate. The ESD shield configured to increase the ESD hardness of the package. The ESD shield can further serve to stiffen the package to prevent warping and operate as a heat spreader.
    Type: Grant
    Filed: December 17, 2008
    Date of Patent: September 4, 2012
    Assignee: LSI Corporation
    Inventors: Choshu Ito, William M. Loh, Rajagopalan Parthasarathy
  • Patent number: 7777996
    Abstract: A system and method for protecting a circuit. The system includes a protection circuit that includes an inverter and a capacitor coupled to the inverter. The inverter and the capacitor are implemented using logic circuits of a circuit core, and the inverter shunts electrostatic discharge ESD current through the capacitor. According to the system and method disclosed herein, because the protection circuit shunt circuit shunts ESD current using logic circuits of the circuit core, ESD protection is achieved while not requiring large FETs. Also, the protection circuit protects circuits against ESD events that conventional FET cannot protect.
    Type: Grant
    Filed: June 30, 2005
    Date of Patent: August 17, 2010
    Assignee: LSI Corporation
    Inventors: William M. Loh, Ken Doniger, Payman Zarkesh-Ha, Jau-Wen Chen, Choshu Ito
  • Patent number: 7551414
    Abstract: An improvement to a digital integrated circuit of the type having a functional circuit that is susceptible to damage from an electrostatic discharge. An electrostatic discharge protection element is placed in series with the functional circuit and disposed upstream in a normal direction of current flow from the functional circuit. The electrostatic discharge protection element includes at least one of a resistive choke that exhibits thermal runaway and an inductive choke.
    Type: Grant
    Filed: December 15, 2005
    Date of Patent: June 23, 2009
    Assignee: LSI Corporation
    Inventors: William M. Loh, Choshu Ito, Jau-Wen Chen
  • Publication number: 20090104735
    Abstract: Embodiments of the invention include a semiconductor integrated circuit package that includes a substrate having an integrated circuit die attached thereto. The package includes a ESD shield attached to the substrate. The ESD shield configured to increase the ESD hardness of the package. The ESD shield can further serve to stiffen the package to prevent warping and operate as a heat spreader.
    Type: Application
    Filed: December 17, 2008
    Publication date: April 23, 2009
    Applicant: LSI Logic Corporation
    Inventors: Choshu Ito, William M. Loh, Rajagopalan Parthasarathy
  • Patent number: 7498664
    Abstract: Embodiments of the invention include a semiconductor integrated circuit package that includes a substrate having an integrated circuit die attached thereto. The package includes a ESD shield attached to the substrate. The ESD shield configured to increase the ESD hardness of the package. The ESD shield can further serve to stiffen the package to prevent warping and operate as a heat spreader.
    Type: Grant
    Filed: December 14, 2005
    Date of Patent: March 3, 2009
    Assignee: LSI Corporation
    Inventors: Choshu Ito, William M. Loh, Rajagopalan Parthasarathy
  • Patent number: 7379281
    Abstract: An electrostatic discharge protection circuit adapted to reduce an electrostatic discharge event on a line of an integrated circuit. The protection circuit includes an NMOS transistor having a source contact that is electrically connected to the line. A drain contact is electrically connected to a logical low voltage, and a gate contact is also electrically connected to the logical low voltage, through a resistor. A substrate bias pump is electrically connected to a back gate of the NMOS transistor, where the bias pump provides a steady state direct current negative bias during normal operation of the integrated circuit when there is no electrostatic discharge event.
    Type: Grant
    Filed: November 28, 2005
    Date of Patent: May 27, 2008
    Assignee: LSI Logic Corporation
    Inventors: William M. Loh, Minxuan Liu, Jau-Wen Chen
  • Patent number: 7375543
    Abstract: The present invention provides a system and method for electrostatic discharge (ESD) testing. The system includes a circuit that has a switch coupled to an input/output (I/O) circuit of a device under test (DUT), a charge source coupled to the switch, and a control circuit coupled to the switch, wherein the control circuit turns on the switch to discharge an ESD current from the charge source to the I/O circuit, and wherein the circuit is integrated into the DUT. According to the system and method disclosed herein, the system provides on-chip ESD testing of a DUT without requiring expensive and specialized test equipment.
    Type: Grant
    Filed: July 21, 2005
    Date of Patent: May 20, 2008
    Assignee: LSI Corporation
    Inventors: Choshu Ito, William M. Loh, Jau-Wen Chen
  • Patent number: 7332917
    Abstract: A method for calculating frequency-dependent impedance in an integrated circuit (IC) having transistors coupled together by a line follows. First, partition the line into a plurality of rectangles of constant material. Then, solve for the minimum dissipated power in the plurality of rectangles. Finally, determine the frequency-dependent impedance from the minimum dissipated power.
    Type: Grant
    Filed: September 21, 2004
    Date of Patent: February 19, 2008
    Assignee: LSI Logic Corporation
    Inventors: Kenneth J. Doniger, William M. Loh
  • Patent number: 7014957
    Abstract: The subject invention is a system, apparatus and/or method of forming interconnects on a semiconductor wafer. Particularly, the subject invention provides interconnect routing using parallel lines on a semiconductor wafer. The method includes producing a plurality of spaced, parallel interconnects on a wafer, and producing interruptions in selective ones of the plurality of interconnects where the connection should be disrupted. Preferably, the plurality of spaced, parallel lines are formed over the entire die region of the wafer and are spaced from one another by a predetermined width. In one form, a mask having a plurality of spaced, parallel lines may be used.
    Type: Grant
    Filed: December 31, 2002
    Date of Patent: March 21, 2006
    Assignee: LSI Logic Corporation
    Inventors: Paymen Zarkesh-Ha, Kenneth J Doniger, William M. Loh
  • Patent number: 6961915
    Abstract: A method and system for designing a dummy grid in an open area of a circuit adjacent to at least one metal line comprising the circuits is disclosed. The method and system include patterning dummy lines in the dummy grid adjacent to metal signal lines, and patterning non-floating dummy lines in the dummy grid adjacent to metal power lines. The method and system further include varying sizes and spacing of the dummy lines in the respective columns of the dummy grid based on the distance between each column and the adjacent metal line, to achieve a balance between planarization and performance.
    Type: Grant
    Filed: November 6, 2002
    Date of Patent: November 1, 2005
    Assignee: LSI Logic Corporation
    Inventors: William M. Loh, Benjamin Mbouombouo, Peter J. Wright
  • Publication number: 20040088669
    Abstract: A method and system for designing a dummy grid in an open area of a circuit adjacent to at least one metal line comprising the circuits is disclosed. The method and system include patterning dummy lines in the dummy grid adjacent to metal signal lines, and patterning non-floating dummy lines in the dummy grid adjacent to metal power lines. The method and system further include varying sizes and spacing of the dummy lines in the respective columns of the dummy grid based on the distance between each column and the adjacent metal line, to achieve a balance between planarization and performance.
    Type: Application
    Filed: November 6, 2002
    Publication date: May 6, 2004
    Inventors: William M. Loh, Benjamin Mbouombouo, Peter J. Wright
  • Patent number: 5964030
    Abstract: An apparatus and method for balancing the flow of molten molding compound above and below an integrated circuit assembly during encapsulation of the assembly. An annular shaped layer of material is placed over the bonding fingers of a leadframe such that the annular shaped layer of material peripherally surrounds the centrally located opening in the leadframe. The annular shaped layer of material has sufficient width and thickness to slow the flow of molten molding material over the top surface of the integrated circuit assembly to the same speed as the flow of molten material under the bottom surface of the integrated circuit package assembly. In so doing, the present invention reduces the formation of blowholes or voids in encapsulated integrated circuit packages.
    Type: Grant
    Filed: February 23, 1998
    Date of Patent: October 12, 1999
    Assignee: VLSI Technology, Inc.
    Inventors: Sang S. Lee, William M. Loh
  • Patent number: 5561328
    Abstract: A semiconductor chip having a number of bonding pads on one face is mounted on a set of matching, mirror-image bonding pads on a packaging substrate, in a flip chip configuration. An alignment template is formed on and permanently secured to the substrate, and takes the form of a frame surrounding the substrate bonding pads. The height of the template is sufficient to receive the edges of the chip and hold the chip in place while the assembly is being transported to the soldering operation. No alignment operation is required, since the chip is merely placed in the receptacle formed by the template. The template is of course aligned with the substrate bonding pads when the template is created. The template can be formed on the substrate using photolithographic techniques, and, preferably, the template itself is formed of a photo-definable material.
    Type: Grant
    Filed: April 14, 1995
    Date of Patent: October 1, 1996
    Assignee: Digital Equipment Corporation
    Inventors: Thomas J. Massingill, William M. Loh
  • Patent number: 5448825
    Abstract: An encapsulated electrically and thermally enhanced integrated circuit is disclosed. An integrated-circuit die is attached to a thermally conductive, electrically-insulated substrate. A lead frame having inwardly-extending bonding fingers has the bottom sides thereof attached to the top of the substrate. A contiguous layer of insulating material is bonded to the top sides of the bonding fingers, such that the layer of insulating material peripherally surrounds the integrated-circuit die. A conductive layer of material is then bonded to the top of the insulating layer. A second layer of insulating material followed by a second conductive layer may be bonded on top of the first conductive layer. Electrical connections are made from the integrated-circuit die to the conductive layers surrounding the die. The device is then encapsulated in a plastic material.
    Type: Grant
    Filed: March 25, 1994
    Date of Patent: September 12, 1995
    Assignee: VLSI Technology, Inc.
    Inventors: Sang S. Lee, William M. Loh
  • Patent number: 5413964
    Abstract: A semiconductor chip having a number of bonding pads on one face is mounted on a set of matching, mirror-image bonding pads on a packaging substrate, in a flip chip configuration. An alignment template is formed on and permanently secured to the substrate, and takes the form of a frame surrounding the substrate bonding pads. The height of the template is sufficient to receive the edges of the chip and hold the chip in place while the assembly is being transported to the soldering operation. No alignment operation is required, since the chip is merely placed in the receptacle formed by the template. The template is of course aligned with the substrate bonding pads when the template is created. The template can be formed on the substrate using photolithographic techniques, and, preferably, the template itself is formed of a photo-definable material.
    Type: Grant
    Filed: June 24, 1991
    Date of Patent: May 9, 1995
    Assignee: Digital Equipment Corporation
    Inventors: Thomas J. Massingill, William M. Loh
  • Patent number: 5331511
    Abstract: An encapsulated electrically and thermally enhanced integrated circuit is disclosed. An integrated-circuit die is attached to a thermally conductive, electrically-insulated substrate. A lead frame having inwardly-extending bonding fingers has the bottom sides thereof attached to the top of the substrate. A contiguous layer of insulating material is bonded to the top sides of the bonding fingers, such that the layer of insulating material peripherally surrounds the integrated-circuit die. A conductive layer of material is then bonded to the top of the insulating layer. A second layer of insulating material followed by a second conductive layer may be bonded on top of the first conductive layer. Electrical connections are made from the integrated-circuit die to the conductive layers surrounding the die. The device is then encapsulated in a plastic material.
    Type: Grant
    Filed: March 25, 1993
    Date of Patent: July 19, 1994
    Assignee: VLSI Technology, Inc.
    Inventors: Sang S. Lee, William M. Loh