Patents by Inventor Aritharan Thurairajaratnam

Aritharan Thurairajaratnam 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).

  • Publication number: 20040164758
    Abstract: A probe structure for testing impedance of a package substrate using time domain reflectometry. A connector electrically connects the probe structure to a time domain reflectometry tester, where the connector has a signal conductor and a ground conductor. An electrically conductive cantilever signal pin is electrically connected to the signal conductor. The electrically conductive cantilever signal pin has a tip for making an electrical connection with an electrically conductive structure to be tested on the package substrate. The electrically conductive cantilever signal pin is electrically isolated by and sheathed within a ground shield that is electrically connected to at least one of the ground conductor and electrically conductive cantilever ground pins. The electrically conductive cantilever ground pins are electrically connected to the ground conductor.
    Type: Application
    Filed: February 21, 2003
    Publication date: August 26, 2004
    Inventors: Mohan R. Nagar, Aritharan Thurairajaratnam
  • Patent number: 6777803
    Abstract: An improvement to an integrated circuit package substrate of the type that has a bonding ring with an exposed upper surface, where a first portion of the exposed upper surface is for receiving a molding compound and a second portion of the exposed upper surface is for receiving an electrical connection. A solder mask is formed on the first portion of the exposed upper surface of the bonding ring.
    Type: Grant
    Filed: August 28, 2002
    Date of Patent: August 17, 2004
    Assignee: LSI Logic Corporation
    Inventors: Maurice Othieno, Aritharan Thurairajaratnam, Manickam Thavarajah, Pradip D. Patei, Severino A. Legaspi, Jr.
  • Publication number: 20040105241
    Abstract: A stiffener for reinforcing a package integrated circuit. The stiffener includes a rigid planar element having a first surface for bonding to a package substrate. The rigid planar element forms a major interior aperture for receiving and surrounding an integrated circuit on all sides of the integrated circuit. The rigid planar element also forms a minor interior aperture for receiving and surrounding a secondary circuit structure on at least three sides of the secondary circuit structure. In this manner, the stiffener provides structural support to the integrated circuit package, which reduces and preferably eliminates twisting and warping of the substrate package as it heats and is subjected to other stresses.
    Type: Application
    Filed: December 3, 2002
    Publication date: June 3, 2004
    Inventors: Yogendra Ranade, Anand Govind, Kumar Nagarajan, Farshad Ghahghahi, Aritharan Thurairajaratnam
  • Patent number: 6744130
    Abstract: A package substrate having separate routing layers for transmitter signals and receiver signals, which signals are routed in differential pairs. The differential pairs of signal routing lines are isolated between a separate ground plane for transmitter and receiver traces and dedicated power planes, where a single power plane is dedicated to a single differential pair of signal routing lines. In this manner, a high degree of electrical isolation exists not only between the transmitter signal traces and the receiver signal traces, which are on different layers, but also between different differential pairs of signal routing lines on the same layer, each of which has its own dedicated power plane. Thus, a very high speed core routing system can be designed in a package substrate that can then be adapted as necessary to support a broad range of different integrated circuit designs.
    Type: Grant
    Filed: July 8, 2003
    Date of Patent: June 1, 2004
    Assignee: LSI Logic Corporation
    Inventors: Leah M. Miller, Aritharan Thurairajaratnam, Edwin M. Fulcher
  • Publication number: 20040070065
    Abstract: A die wire bonded to a semiconductor substrate includes insulated signal wire, insulated power wires and uninsulated ground wires between the die and the semiconductor substrate. A conductive material is provided over the signal, power and ground wire bonds which provides an electrical connection between the uninsulated ground wires. The conductive material follows the same profile as the wire bonds and provides a controlled impedance environment for the signal wirebonds.
    Type: Application
    Filed: October 11, 2002
    Publication date: April 15, 2004
    Inventors: Aritharan Thurairajaratnam, Ramaswamy Ranganathan
  • Publication number: 20040070402
    Abstract: A probe structure with a connector connecting the probe structure to a time domain reflectometry tester, where the connector has a signal conductor and a ground conductor. A back side layer is connected to the connector. A probe side layer with contacts is sandwiched with the back side layer in a layered substrate. The probe side layer has a centrally disposed signal contact and surrounding ground contacts. A conductive layer is disposed between the back side layer and the probe side layer. The conductive layer is connected to the ground conductor of the connector and to the ground contacts of the probe side layer contacts. A via extends from the back side layer to the probe side layer. The via is connected to the signal conductor of the connector, and is also connected to the centrally disposed signal contact of the probe side layer contacts. The via does not make connection with the conductive layer.
    Type: Application
    Filed: October 9, 2002
    Publication date: April 15, 2004
    Inventors: Aritharan Thurairajaratnam, Mohan R. Nagar
  • Patent number: 6717423
    Abstract: A probe structure with a connector connecting the probe structure to a time domain reflectometry tester, where the connector has a signal conductor and a ground conductor. A back side layer is connected to the connector. A probe side layer with contacts is sandwiched with the back side layer in a layered substrate. The probe side layer has a centrally disposed signal contact and surrounding ground contacts. A conductive layer is disposed between the back side layer and the probe side layer. The conductive layer is connected to the ground conductor of the connector and to the ground contacts of the probe side layer contacts. A via extends from the back side layer to the probe side layer. The via is connected to the signal conductor of the connector, and is also connected to the centrally disposed signal contact of the probe side layer contacts. The via does not make connection with the conductive layer.
    Type: Grant
    Filed: October 9, 2002
    Date of Patent: April 6, 2004
    Assignee: LSI Logic Corporation
    Inventors: Aritharan Thurairajaratnam, Mohan R. Nagar
  • Publication number: 20040056939
    Abstract: A method of forming a photo-resist image on a substrate, such as a conductive film. The method provides that a photo-resist image is printed directly onto the conductive film, such as by using an ink jet printer. Specifically, a CAD image may be sent from a computer to the ink jet printer, and the ink jet printer may use the CAD image to print the photo-resist image. The method may provide that a copper film is applied to a dielectric substrate, and then the photo-resist image is printed directly onto the copper film. Then, at least a portion of the copper film is removed, such as by etching, and at least a portion of the photo-resist image which has been printed on the copper film is removed, such as by etching. By printing the photo-resist image directly onto the copper film, it is not necessary to perform steps such as: applying a mask, exposing to UV light, and developing.
    Type: Application
    Filed: September 25, 2002
    Publication date: March 25, 2004
    Inventors: Manickam Thavarajah, Aritharan Thurairajaratnam, Alejandro Lacap
  • Publication number: 20040041252
    Abstract: An improvement to an integrated circuit package substrate of the type that has a bonding ring with an exposed upper surface, where a first portion of the exposed upper surface is for receiving a molding compound and a second portion of the exposed upper surface is for receiving an electrical connection. A solder mask is formed on the first portion of the exposed upper surface of the bonding ring.
    Type: Application
    Filed: August 28, 2002
    Publication date: March 4, 2004
    Inventors: Maurice Othieno, Aritharan Thurairajaratnam, Manickam Thavarajah, Pradip D. Patel, Severino A. Legaspi
  • Publication number: 20030230428
    Abstract: A method for fabricating a semiconductor package having a 2-layer substrate, which includes an array of solder balls, is disclosed. The method includes patterning signal traces on a top layer of the substrate and identifying groups of signal traces to isolate. According to the present invention, a grounded isolation trace is then patterned adjacent to one of the groups of traces to isolate the signal traces, thereby providing noise shielding. In a preferred embodiment, the grounded isolation trace is provided with multiple vias, rather than only one. In a further aspect of the present invention a row of solder balls is connected together and to ground to create a bottom-layer isolating ground trace to further reduce noise. The bottom-layer isolating ground trace may be connected to the top-layer isolating ground trace using a via.
    Type: Application
    Filed: March 11, 2003
    Publication date: December 18, 2003
    Inventors: Wee K. Liew, Aritharan Thurairajaratnam, Nadeem Haque
  • Patent number: 6608376
    Abstract: An integrated circuit package is provided that allows high density routing of signal lines. A substrate of the package may include an upper surface upon which a bonding finger resides, a lower surface upon which a solder ball resides, and a signal conductor plane on which a signal trace conductor resides a dielectrically spaced distance between the upper surface and the lower surface. A first via may extend perpendicularly from the upper surface, connecting the bonding finger to the first portion of the signal trace conductor. A second via may extend perpendicularly from the lower surface, connecting the solder ball to the second portion of the signal trace conductor. The routing of the vias and signal trace conductors may cause the signal lines to either fan into or away from the area of the integrated circuit package adapted to receive the integrated circuit.
    Type: Grant
    Filed: March 25, 2002
    Date of Patent: August 19, 2003
    Assignee: LSI Logic Corporation
    Inventors: Wee Keong Liew, Aritharan Thurairajaratnam, Maniam Alagaratnam
  • Patent number: 6566167
    Abstract: A method for fabricating a semiconductor package having a 2-layer substrate, which includes an array of solder balls, is disclosed. The method includes patterning signal traces on a top layer of the substrate and identifying groups of signal traces to isolate. According to the present invention, a grounded isolation trace is then patterned adjacent to one of the groups of traces to isolate the signal traces, thereby providing noise shielding. In a preferred embodiment, the grounded isolation trace is provided with multiple vias, rather than only one. In a further aspect of the present invention a row of solder balls is connected together and to ground to create a bottom-layer isolating ground trace to further reduce noise. The bottom-layer isolating ground trace may be connected to the top-layer isolating ground trace using a via.
    Type: Grant
    Filed: July 31, 2001
    Date of Patent: May 20, 2003
    Assignee: LSI Logic Corporation
    Inventors: Wee K. Liew, Aritharan Thurairajaratnam, Nadeem Haque
  • Patent number: 6555914
    Abstract: A method of forming a via in a circuit, such that parasitic capacitance is reduced. The surface layers of the circuit are identified, to which continuity with the via is desired, and secondary layers of the circuit are also identified. Via lands are formed only on the surface layers and not on the secondary layers. The via lands are formed in first portions of the surface layers, where the via is to pass through the surface layers. Nonconductive cut outs are formed in second portions of the secondary layers where the via is to pass through the secondary layers. The surface layers and the secondary layers of the circuit are laminated together. The first portions of the surface layers are aligned with the second portions of the secondary layers. A through hole is formed through the via lands formed in the surface layers, and also through the cut outs formed in the secondary layers. The via is formed in the through hole.
    Type: Grant
    Filed: October 12, 2001
    Date of Patent: April 29, 2003
    Assignee: LSI Logic Corporation
    Inventors: Aritharan Thurairajaratnam, Pradip D. Patel, Manickam Thavarajah, Hong T. Lim
  • Patent number: 6534968
    Abstract: An apparatus for detecting failures in electrical connections between an integrated circuit package substrate and a circuit board. The substrate has substrate electrical contacts that are electrically connected one to another in first sets in a first region of the substrate. The circuit board has circuit board electrical contacts that are electrically connected one to another in second sets in a second region of the circuit board. The substrate electrical contacts align with and make electrical contact with the circuit board electrical contacts. The first region of the substrate aligns with the second region of the circuit board when the substrate electrical contacts make electrical contact with the circuit board electrical contacts. The first sets of substrate electrical contacts form chains of electrical contacts with the second sets of circuit board electrical contacts. The chains of electrical contacts loop back and forth electrically between the substrate and the circuit board.
    Type: Grant
    Filed: August 10, 2001
    Date of Patent: March 18, 2003
    Assignee: LSI Logic Corporation
    Inventors: Leah M. Miller, Anand Govind, Zafer Kutlu, Chao-Wen Chung, Aritharan Thurairajaratnam
  • Patent number: 6531932
    Abstract: A method for fabricating a microstrip package to optimize signal trace impedance control is disclosed. The method includes patterning a plurality of signal traces on a multilayer substrate, and patterning a plurality of guard traces on the multilayer substrate, that are interspersed alternately among the signal traces to provide noise shielding between the signal traces. In a further embodiment, the traces are patterned on the substrate with a width that is adjusted at different locations based on the presence the guard traces to enable the package to meet a particular impedance requirement.
    Type: Grant
    Filed: June 27, 2001
    Date of Patent: March 11, 2003
    Assignee: LSI Logic Corporation
    Inventors: Anand Govind, Farshad Ghahghahi, Aritharan Thurairajaratnam
  • Patent number: 6496081
    Abstract: The present invention provides a transmission equalization system for use with an integrated circuit package employing a substrate. In one embodiment, the transmission equalization system includes a signal transmission subsystem having a pair of transmission line conductors located in the substrate and employing a differential electrical signal. The transmission equalization system also includes an equalization subsystem located proximate the pair of transmission line conductors that employs at least one aperture positioned and oriented to provide a substantially equivalent transmission environment for each of the pair of transmission line conductors.
    Type: Grant
    Filed: September 28, 2001
    Date of Patent: December 17, 2002
    Assignee: LSI Logic Corporation
    Inventors: Anand Govind, Aritharan Thurairajaratnam
  • Patent number: 6459049
    Abstract: A structure for receiving electrical signals near a central portion of the structure and distributing the electrical signals to a peripheral portion of the structure. The structure has a first set of contacts arranged in an array near the central portion of the structure. Electrically conductive traces connect the first set of contacts to a second set of contacts, where each of the electrically conductive traces has at least a first segment, a second segment, and a third segment. The first segment of each of the electrically conductive traces has relatively narrow width and spacing. The first segment of each of the electrically conductive traces is connected on a first end of the first segment to one of the first set of contacts and on a second end of the first segment to the second segment of each of the electrically conductive traces. The second segment of each of the electrically conductive traces has relatively intermediate width and spacing.
    Type: Grant
    Filed: June 20, 2001
    Date of Patent: October 1, 2002
    Assignee: LSI Logic Corporation
    Inventors: Leah M. Miller, Farshad Ghahghahi, Edwin M. Fulcher, Aritharan Thurairajaratnam
  • Patent number: 6396140
    Abstract: A semiconductor package is disclosed. According to one embodiment, the package comprises a substrate having a top surface with traces thereon and a bottom surface with solder balls thereon, the substrate comprising at least three material layers defining at least four substantially planar metal layers, wherein one of the metal layers comprises a reference layer that serves as a reference to both traces on a metal layer above the reference layer and traces on a metal layer below the reference layer. A semiconductor die is mounted to the substrate and bonding wires electrically connect the semiconductor die to the traces on the top surface of the substrate. The traces on the top surface of the substrate are electrically connect to the solder balls through vias and possibly through routing on another metal layer.
    Type: Grant
    Filed: August 3, 2000
    Date of Patent: May 28, 2002
    Assignee: LSI Logic Corporation
    Inventors: Nitin Juneja, Aritharan Thurairajaratnam
  • Patent number: 6225690
    Abstract: A semiconductor package is disclosed. According to one embodiment, the package comprises a substrate having a top surface with traces thereon and a bottom surface with solder balls thereon, the substrate comprising at least three material layers defining at least four substantially planar metal layers, wherein one of the metal layers comprises a reference layer that serves as a reference to both traces on a metal layer above the reference layer and traces on a metal layer below the reference layer. A semiconductor die is mounted to the substrate and bonding wires electrically connect the semiconductor die to the traces on the top surface of the substrate. The traces on the top surface of the substrate are electrically connect to the solder balls through vias and possibly through routing on another metal layer.
    Type: Grant
    Filed: December 10, 1999
    Date of Patent: May 1, 2001
    Assignee: LSI Logic Corporation
    Inventors: Nitin Juneja, Aritharan Thurairajaratnam
  • Patent number: 6127728
    Abstract: A semiconductor package is disclosed. According to one embodiment, the package comprises a substrate having a top surface with traces thereon and a bottom surface with solder balls thereon, the substrate comprising at least three material layers defining at least four substantially planar metal layers, wherein one of the metal layers comprises a reference layer that serves as a reference to both traces on a metal layer above the reference layer and traces on a metal layer below the reference layer. A semiconductor die is mounted to the substrate and bonding wires electrically connect the semiconductor die to the traces on the top surface of the substrate. The traces on the top surface of the substrate are electrically connect to the solder balls through vias and possibly through routing on another metal layer.
    Type: Grant
    Filed: June 24, 1999
    Date of Patent: October 3, 2000
    Assignee: LSI Logic Corporation
    Inventors: Nitin Juneja, Aritharan Thurairajaratnam