Patents by Inventor Sarvotham M. Bhandarkar

Sarvotham M. Bhandarkar 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: 6999494
    Abstract: A planar wafer-level packaging method is provided for a laser and a microlens. Light from the laser is directed and shaped by the microlens to couple into an external light guide. A plurality of such assemblies, each comprising a laser and a microlens may be assembled on a single planar substrate. A tapered surface is formed on the microlens. The microlens may be formed from a silicon substrate. The angle of the tapered surface causes an accurate cone or pyramid shape. The tapered surface is formed such that the axis of the cone or pyramid is aligned with the optical axis of the lens. The lens may then be aligned with the optical axis of the laser. A light guide receptacle is formed with a tapered surface that matches the tapered surface of the microlens. The tapered surface of the receptacle is formed such that the axis of the cone or pyramid is aligned with the optical axis of the receptacle. The receptacle may then be passively aligned with the microlens by mating the tapered surfaces.
    Type: Grant
    Filed: June 18, 2003
    Date of Patent: February 14, 2006
    Assignee: Photodigm, Inc.
    Inventor: Sarvotham M. Bhandarkar
  • Patent number: 6970491
    Abstract: A planar wafer-level packaging method is provided for a laser and a monitor photo detector. The laser and photo detector are affixed to a planar substrate. The planar substrate provides electrical connections to the components. A lens cap with a microlens is formed and affixed to the substrate with a seal. The lens cap forms a hermetically sealed cavity enclosing the laser and photo detector. The inside surface of the lens cap has a reflective coating with a central opening over the emitting aperture of the laser. The central opening has an anti-reflective coating. Light from the laser is directed and shaped by the lens cap to couple into an external light guide. Residual light from the edge of the laser reflects off the inside surface of the lens cap and is incident upon the photo detector. In an alternate method, the laser may be packaged using flip-chip assembly.
    Type: Grant
    Filed: October 30, 2002
    Date of Patent: November 29, 2005
    Assignee: Photodigm, Inc.
    Inventor: Sarvotham M. Bhandarkar
  • Publication number: 20040258110
    Abstract: A planar wafer-level packaging method is provided for a laser and a microlens. Light from the laser is directed and shaped by the microlens to couple into an external light guide. A plurality of such assemblies, each comprising a laser and a microlens may be assembled on a single planar substrate. A tapered surface is formed on the microlens. The microlens may be formed from a silicon substrate. The angle of the tapered surface causes an accurate cone or pyramid shape. The tapered surface is formed such that the axis of the cone or pyramid is aligned with the optical axis of the lens. The lens may then be aligned with the optical axis of the laser. A light guide receptacle is formed with a tapered surface that matches the tapered surface of the microlens. The tapered surface of the receptacle is formed such that the axis of the cone or pyramid is aligned with the optical axis of the receptacle. The receptacle may then be passively aligned with the microlens by mating the tapered surfaces.
    Type: Application
    Filed: June 18, 2003
    Publication date: December 23, 2004
    Applicant: Photodigm, Inc.
    Inventor: Sarvotham M. Bhandarkar
  • Publication number: 20040101020
    Abstract: A planar wafer-level packaging method is provided for a laser and a monitor photo detector. The laser and photo detector are affixed to a planar substrate. A lens cap with a microlens is formed and affixed to the substrate with a seal. The lens cap forms a hermetically sealed cavity enclosing the laser and photo detector. Light from the laser is directed and shaped by the lens cap to couple into an external light guide. In an alternate method, the laser may be packaged using flip-chip assembly. A precision protrusion is also provided in the receptacle that fits into a photo-lithographically defined cavity in the substrate of the planar subpackage, thereby passively effecting and maintaining alignment of the axis of the microlens with respect to the central axis of the mating ferrule. The axial distance, in the direction of the laser beam, between the lens and the mating connector ferrule is controlled by the connector stop or front face of the MT ferrule.
    Type: Application
    Filed: November 26, 2002
    Publication date: May 27, 2004
    Applicant: Photodigm, Inc.
    Inventor: Sarvotham M. Bhandarkar
  • Publication number: 20040086011
    Abstract: A planar wafer-level packaging method is provided for a laser and a monitor photo detector. The laser and photo detector are affixed to a planar substrate. The planar substrate provides electrical connections to the components. A lens cap with a microlens is formed and affixed to the substrate with a seal. The lens cap forms a hermetically sealed cavity enclosing the laser and photo detector. The inside surface of the lens cap has a reflective coating with a central opening over the emitting aperture of the laser. The central opening has an anti-reflective coating. Light from the laser is directed and shaped by the lens cap to couple into an external light guide. Residual light from the edge of the laser reflects off the inside surface of the lens cap and is incident upon the photo detector. In an alternate method, the laser may be packaged using flip-chip assembly.
    Type: Application
    Filed: October 30, 2002
    Publication date: May 6, 2004
    Applicant: Photodigm, Inc.
    Inventor: Sarvotham M. Bhandarkar
  • Patent number: 6351032
    Abstract: Improved structures for and methods for assembling heatspreader attachments in integrated circuit packages permit attachment of a relatively low cost heatspreader having a high coefficient of thermal expansion directly to the back of a die while maximizing thermal performance, mechanical integrity and reliability of the assembly. The improvements are realized through the use of specific adhesive materials to attach the heatspreader to the die, heatspreader geometries, adhesive geometries, assembly techniques and underfill geometries.
    Type: Grant
    Filed: January 20, 2000
    Date of Patent: February 26, 2002
    Assignee: National Semiconductor Corporation
    Inventors: Bernard K H Lee, Ben T C Tan, Emillo F. Mallare, Jr., Sarvotham M. Bhandarkar, Subodh Mhaisalkar, Ai Min Tan
  • Patent number: 5967577
    Abstract: A dispenser contains a chamber enclosed by an upper wall and a lower wall, both walls are oriented parallel to each other. The upper wall has a vertically bored inlet port and the lower wall has a plurality of vertically bored outlet ports for providing access to the chamber. The outlet ports are geometrically arranged in an array pattern characterized by equidistantly spaced rows and columns of bores. There is a plurality of baffle plates interposed between the upper wall and the lower wall. The baffle plates, which are spatially separated from each other, are oriented parallel to and spatially separated from the upper and lower walls. The baffle plates have a plurality of vertically bored holes for providing access between the inlet port and the outlet ports, whereby the dispenser is effective in providing homogeneous flow of fluid through the outlet ports.
    Type: Grant
    Filed: September 3, 1998
    Date of Patent: October 19, 1999
    Assignee: Institute of Microelectronics
    Inventors: Sarvotham M. Bhandarkar, Kishore Kumar Chakravorty, Tai Chong Chai, Jian Hua Wu
  • Patent number: 5836520
    Abstract: A dispenser contains a chamber enclosed by an upper wall and a lower wall, both walls are oriented parallel to each other. The upper wall has a vertically bored inlet port and the lower wall has a plurality of vertically bored outlet ports for providing access to the chamber. The outlet ports are geometrically arranged in an array pattern characterized by equidistantly spaced rows and columns of bores. There is a plurality of baffle plates interposed between the upper wall and the lower wall. The baffle plates, which are spatially separated from each other, are oriented parallel to and spatially separated from the upper and lower walls. The baffle plates have a plurality of vertically bored holes for providing access between the inlet port and the outlet ports, whereby the dispenser is effective in providing homogeneous flow of fluid through the outlet ports.
    Type: Grant
    Filed: January 4, 1996
    Date of Patent: November 17, 1998
    Assignee: Institute of Microelectronics
    Inventors: Sarvotham M. Bhandarkar, Kishore Kumar Chakravorty, Tai Chong Chai, Jian Hua Wu
  • Patent number: 5773878
    Abstract: The present invention relates to a lead frame design for IC packaging to reduce chip stress and deformation and to improve mold filling. The die-pad is split into several sections which are jointed together by flexible expansion joints. The split die-pad allows relative motion between the pad and the chip during die attach cure. It also breaks down the total die pad area (and length) that is rigidly attached to the chip into smaller sections. These two factors reduce the magnitude of coefficient-of-thermal expansion (CTE) mismatch and out of plane deformation of the assembly, resulting in lower chip stress and deformation and improved package moldability.
    Type: Grant
    Filed: January 4, 1996
    Date of Patent: June 30, 1998
    Assignee: Institute of Microelectronics National University of Singapore
    Inventors: Thiam Beng Lim, Sarvotham M. Bhandarkar