Patents by Inventor Jayesh Bharathan

Jayesh Bharathan 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: 7259033
    Abstract: Light emitting device die having a mesa configuration on a substrate and an electrode on the mesa are attached to a submount in a flip-chip configuration by forming predefined pattern of conductive die attach material on at least one of the electrode and the submount and mounting the light emitting device die to the submount. The predefined pattern of conductive die attach material is selected so as to prevent the conductive die attach material from contacting regions of having opposite conductivity types when the light emitting device die is mounted to the submount. The predefined pattern of conductive die attach material may provide a volume of die attach material that is less than a volume defined by an area of the electrode and a distance between the electrode and the submount. Light emitting device dies having predefined patterns of conductive die attach material are also provided.
    Type: Grant
    Filed: August 17, 2004
    Date of Patent: August 21, 2007
    Assignees: Cree, Inc., Cree Microwave, LLC
    Inventors: David B. Slater, Jr., Jayesh Bharathan, John Edmond, Mark Raffetto, Anwar Mohammed, Peter S. Andrews, Gerald H. Negley
  • Patent number: 7259402
    Abstract: A method and resulting structures are disclosed for fabricating a high efficiency high extraction light emitting diode suitable for packaging. The method includes the steps of adding a light emitting active portion of wide-bandgap semiconductor material to a conductive silicon carbide substrate, joining the added active portion to a conductive sub-mounting structure, and removing a portion of the silicon carbide substrate opposite the added active portion to thereby reduce the overall thickness of the joined substrate, active portion and sub-mounting structure. The resulting the sub-mounting structure can be joined to a lead frame with the active portion positioned between the silicon carbide substrate and the sub-mounting structure to thereby use the sub-mounting structure to separate the active portion from the lead frame and avoid undesired electrical contact between the active portion and the lead frame.
    Type: Grant
    Filed: September 22, 2004
    Date of Patent: August 21, 2007
    Assignee: Cree, Inc.
    Inventors: John Adam Edmond, Jayesh Bharathan, David Beardsley Slater, Jr.
  • Publication number: 20060060877
    Abstract: A method and resulting structures are disclosed for fabricating a high efficiency high extraction light emitting diode suitable for packaging. The method includes the steps of adding a light emitting active portion of wide-bandgap semiconductor material to a conductive silicon carbide substrate, joining the added active portion to a conductive sub-mounting structure, and removing a portion of the silicon carbide substrate opposite the added active portion to thereby reduce the overall thickness of the joined substrate, active portion and sub-mounting structure. The resulting the sub-mounting structure can be joined to a lead frame with the active portion positioned between the silicon carbide substrate and the sub-mounting structure to thereby use the sub-mounting structure to separate the active portion from the lead frame and avoid undesired electrical contact between the active portion and the lead frame.
    Type: Application
    Filed: September 22, 2004
    Publication date: March 23, 2006
    Inventors: John Edmond, Jayesh Bharathan, David Slater
  • Publication number: 20060060874
    Abstract: A high efficiency Group III nitride light emitting diode is disclosed. The diode includes a substrate selected from the group consisting of semiconducting and conducting materials, a Group III nitride-based light emitting region on or above the substrate, and, a lenticular surface containing silicon carbide on or above the light emitting region.
    Type: Application
    Filed: March 17, 2005
    Publication date: March 23, 2006
    Inventors: John Edmond, David Slater, Jayesh Bharathan, Matthew Donofrio
  • Publication number: 20060046328
    Abstract: A semiconductor based Light Emitting Device (LED) can include a p-type nitride layer and a metal ohmic contact, on the p-type nitride layer. The metal ohmic contact can have an average thickness of less than about 25 ? and a specific contact resistivity less than about 10?3 ohm-cm2.
    Type: Application
    Filed: July 27, 2005
    Publication date: March 2, 2006
    Inventors: Mark Raffetto, Jayesh Bharathan, Kevin Haberern, Michael Bergmann, David Emerson, James Ibbetson, Ting Li
  • Patent number: 6888167
    Abstract: Light emitting device die having a mesa configuration on a substrate and an electrode on the mesa are attached to a submount in a flip-chip configuration by forming predefined pattern of conductive die attach material on at least one of the electrode and the submount and mounting the light emitting device die to the submount. The predefined pattern of conductive die attach material is selected so as to prevent the conductive die attach material from contacting regions of having opposite conductivity types when the light emitting device die is mounted to the submount. The predefined pattern of conductive die attach material may provide a volume of die attach material that is less than a volume defined by an area of the electrode and a distance between the electrode and the submount. Light emitting device dies having predefined patterns of conductive die attach material are also provided.
    Type: Grant
    Filed: June 27, 2002
    Date of Patent: May 3, 2005
    Assignees: Cree, Inc., Cree Microwave, Inc.
    Inventors: David B. Slater, Jr., Jayesh Bharathan, John Edmond, Mark Raffetto, Anwar Mohammed, Peter S. Andrews, Gerald H. Negley
  • Publication number: 20050017256
    Abstract: Light emitting device die having a mesa configuration on a substrate and an electrode on the mesa are attached to a submount in a flip-chip configuration by forming predefined pattern of conductive die attach material on at least one of the electrode and the submount and mounting the light emitting device die to the submount. The predefined pattern of conductive die attach material is selected so as to prevent the conductive die attach material from contacting regions of having opposite conductivity types when the light emitting device die is mounted to the submount. The predefined pattern of conductive die attach material may provide a volume of die attach material that is less than a volume defined by an area of the electrode and a distance between the electrode and the submount. Light emitting device dies having predefined patterns of conductive die attach material are also provided.
    Type: Application
    Filed: August 17, 2004
    Publication date: January 27, 2005
    Inventors: David Slater, Jayesh Bharathan, John Edmond, Mark Raffeto, Anwar Mohammed, Peter Andrews, Gerald Negley
  • Publication number: 20040227149
    Abstract: A light emitter includes a planar supporting surface, a light source positioned on the spreader region, and an encapsulant positioned on the spreader region to surround the light source. Except where constrained by adhesion to the planar supporting surface, the encapsulant is capable of expanding and contracting in response to a change in temperature so that forces caused by differences in the coefficient of thermal expansion between the different components is minimized. One or more reflective elements can be positioned proximate to the light source to increase the light emitting efficiency of the light emitter. The reflective elements can include the a reflective layer on the spreader region and/or a reflective layer on a portion of the encapsulant.
    Type: Application
    Filed: April 29, 2004
    Publication date: November 18, 2004
    Applicant: Cree, Inc.
    Inventors: James Ibbetson, Jayesh Bharathan, Bernd Keller
  • Publication number: 20040200882
    Abstract: Bonding of flip-chip mounted light emitting devices having an irregular configuration is provided. Light emitting diodes having a shaped substrate are bonded to a submount by applying forces to the substrate an a manner such that shear forces within the substrate do not exceed a failure threshold of the substrate. Bonding a light emitting diode to a submount may be provided by applying force to a surface of a substrate of the light emitting diode that is oblique to a direction of motion of the light emitting diode to thermosonically bond the light emitting diode to the submount. Collets for use in bonding shaped substrates to a submount and systems for bonding shaped substrates to a submount are also provided.
    Type: Application
    Filed: April 27, 2004
    Publication date: October 14, 2004
    Inventors: David B. Slater, Jayesh Bharathan, John Edmond, Mark Raffetto, Anwar Mohammed, Peter S. Andrews, Gerald H. Negley
  • Patent number: 6747298
    Abstract: Bonding of flip-chip mounted light emitting devices having an irregular configuration is provided. Light emitting diodes having a shaped substrate are bonded to a submount by applying forces to the substrate an a manner such that shear forces within the substrate do not exceed a failure threshold of the substrate. Bonding a light emitting diode to a submount may be provided by applying force to a surface of a substrate of the light emitting diode that is oblique to a direction of motion of the light emitting diode to thermosonically bond the light emitting diode to the submount. Collets for use in bonding shaped substrates to a submount and systems for bonding shaped substrates to a submount are also provided.
    Type: Grant
    Filed: June 27, 2002
    Date of Patent: June 8, 2004
    Assignee: Cree, Inc.
    Inventors: David B. Slater, Jr., Jayesh Bharathan, John Edmond, Mark Raffetto, Anwar Mohammed, Peter S. Andrews, Gerald H. Negley
  • Publication number: 20040012027
    Abstract: A high efficiency, high yield solid state emitter package is disclosed exhibiting limited wavelength variations between batches and consistent wavelength and emission characteristics with operation. One embodiment of an emitter package according to the present invention comprises a semiconductor emitter and a conversion material. The conversion material is arranged to absorb substantially all of the light emitting from the semiconductor emitter and re-emit light at one or more different wavelength spectrums of light The conversion material is also arranged so that there is not an excess of conversion material to block the re-emitted light as it emits from the emitter package. The emitter package emitting light at one or more wavelength spectrums from the conversion material's re-emitted light.
    Type: Application
    Filed: June 12, 2003
    Publication date: January 22, 2004
    Applicant: CREE LIGHTING COMPANY
    Inventors: Bernd Keller, James Ibbetson, Yankun Fu, James Seruto, Jayesh Bharathan
  • Publication number: 20030045015
    Abstract: Light emitting device die having a mesa configuration on a substrate and an electrode on the mesa are attached to a submount in a flip-chip configuration by forming predefined pattern of conductive die attach material on at least one of the electrode and the submount and mounting the light emitting device die to the submount. The predefined pattern of conductive die attach material is selected so as to prevent the conductive die attach material from contacting regions of having opposite conductivity types when the light emitting device die is mounted to the submount. The predefined pattern of conductive die attach material may provide a volume of die attach material that is less than a volume defined by an area of the electrode and a distance between the electrode and the submount. Light emitting device dies having predefined patterns of conductive die attach material are also provided.
    Type: Application
    Filed: June 27, 2002
    Publication date: March 6, 2003
    Inventors: David B. Slater, Jayesh Bharathan, John Edmond, Mark Raffetto, Anwar Mohammed, Peter S. Andrews, Gerald H. Negley
  • Publication number: 20030042507
    Abstract: Bonding of flip-chip mounted light emitting devices having an irregular configuration is provided. Light emitting diodes having a shaped substrate are bonded to a submount by applying forces to the substrate an a manner such that shear forces within the substrate do not exceed a failure threshold of the substrate. Bonding a light emitting diode to a submount may be provided by applying force to a surface of a substrate of the light emitting diode that is oblique to a direction of motion of the light emitting diode to thermosonically bond the light emitting diode to the submount. Collets for use in bonding shaped substrates to a submount and systems for bonding shaped substrates to a submount are also provided.
    Type: Application
    Filed: June 27, 2002
    Publication date: March 6, 2003
    Inventors: David B. Slater, Jayesh Bharathan, John Edmond, Mark Raffetto, Anwar Mohammed, Peter S. Andrews, Gerald H. Negley