Patents by Inventor Lawrence H. Herko

Lawrence H. Herko 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: 6436793
    Abstract: A method of forming a semiconductor structure from a first wafer and a second wafer. A pit or groove is formed in a lower surface of the first wafer. The lower surface of the first wafer is bonded to an upper surface of the second wafer. A groove is then formed on an upper surface of the first wafer, such that an opening is formed in the first wafer that exposes at least one alignment reference target on the upper surface of the second wafer. The bonded first wafer and second wafer is then diced using the exposed at least one alignment reference target to form a semiconductor structure.
    Type: Grant
    Filed: December 28, 2000
    Date of Patent: August 20, 2002
    Assignee: Xerox Corporation
    Inventors: Gary A. Kneezel, Daniel E. Kuhman, Brian T. Ormond, Ackerman C. John, Almon P. Fisher, Allan F. Camp, Lawrence H. Herko
  • Publication number: 20020086452
    Abstract: A method of forming a semiconductor structure from a first wafer and a second wafer. A pit or groove is formed in a lower surface of the first wafer. The lower surface of the first wafer is bonded to an upper surface of the second wafer. A groove is then formed on an upper surface of the first wafer, such that an opening is formed in the first wafer that exposes at least one alignment reference target on the upper surface of the second wafer. The bonded first wafer and second wafer is then diced using the exposed at least one alignment reference target to form a semiconductor structure.
    Type: Application
    Filed: December 28, 2000
    Publication date: July 4, 2002
    Inventors: Gary A. Kneezel, Daniel E. Kuhman, Brian T. Ormond, John C. Ackerman, Almon P. Fisher, Allan F. Camp, Lawrence H. Herko
  • Patent number: 5668061
    Abstract: An improved back cut method is provided in a dicing procedure for separating a plurality of printheads formed in a silicon wafer. The wafer has alignment fiducial marks formed within a composite wafer. Infrared light is directed into the wafer and is reflected back through the wafer from the fiducial marks. The reflected light is detected by a CCD camera mounted on a dicing saw. The fiducial coordinates are stored in memory and displayed so that the dicing saw can be aligned with regard to the alignment marks. A back cut operation is enabled so that the saw partially cuts through the composite wafer. A subsequent dicing step separates individual printheads from the wafer.
    Type: Grant
    Filed: August 16, 1995
    Date of Patent: September 16, 1997
    Assignee: Xerox Corporation
    Inventors: Lawrence H. Herko, David J. Collins, Kevin A. Lindamood
  • Patent number: 5637388
    Abstract: A composite resinold/graphite/diamond blade is described having enhanced precision cutting properties. The blade is made by assembling several layers, each layer comprising a veil of non-woven graphite fabric impregnated with a mixture of diamond particles blended into a phenolic resin. Layers are built up in sandwich fashion. In one embodiment described, four layers are formed and, in a heating compression molding operation, the sandwich is compressed into a composite blade having a diameter of 4.7 inches with a thickness of 0.011 inch. The final blade is formed by a die cut and lapping process. The layered construction yields a blade with more consistent cross-section and improves blade wear symmetry. In another embodiment, the layers are tailored to have a grit concentration of the diamond/resin mixture at the periphery or cutting edge.
    Type: Grant
    Filed: August 28, 1995
    Date of Patent: June 10, 1997
    Assignee: Xerox Corporation
    Inventors: Robert M. White, Robert P. Altavela, Alex S. Brougham, Lawrence H. Herko, Robert A. Clingerman
  • Patent number: 5515089
    Abstract: The contiguous inlets of components of a thermal ink jet printhead are sealed by applying a sealant to provide a substantial but not complete seal around the edge of an inlet of the printhead die mounted on a heater plate to provide an edge free of sealant and by injecting a liquid encapsulant to seal the contiguous inlets of the die and a manifold at the edge free of sealant.
    Type: Grant
    Filed: December 8, 1992
    Date of Patent: May 7, 1996
    Assignee: Xerox Corporation
    Inventors: Lawrence H. Herko, Peter J. Nystrom
  • Patent number: 5506610
    Abstract: A method of dicing a printhead wafer containing a plurality of individual print elements into discreet elements. A back side relief feature is formed on the bottom front edge of a thermal ink jet print element from a heater side during a first dicing cut, followed by a second dicing cut from a channel side of the wafer to form a front face nozzle. The back cut feature enables front face maintenance by a wiper blade or other maintenance operation, provides a pocket for excess die bonding adhesive during manufacture, and reduces front face chipping during dicing caused by the saw blade contacting the die wafer mounting media and becoming contaminated. The relief feature may be a square step feature or a beveled back cut feature and may additionally be located on a top front edge of the print element.
    Type: Grant
    Filed: January 30, 1995
    Date of Patent: April 9, 1996
    Assignee: Xerox Corporation
    Inventors: Robert P. Altavela, Lawrence H. Herko, Almon P. Fisher
  • Patent number: 5494698
    Abstract: A resinoid dicing blade having approximately a 20% by volume porosity structure is coated and impregnated with Teflon.RTM. by a process which impregnates the resinoid blade with Teflon.RTM. to about 0.3 to 0.5% by weight. The Teflon.RTM. impregnated dicing blades not only reduces nozzle chipping when bonded silicon wafers are separated into a plurality of individual printhead die, but blade life is significantly increased.
    Type: Grant
    Filed: November 7, 1994
    Date of Patent: February 27, 1996
    Assignee: Xerox Corporation
    Inventors: Robert M. White, Lawrence H. Herko, Robert P. Altavela
  • Patent number: 5408739
    Abstract: A method of dicing a printhead wafer containing a plurality of individual print elements into discreet elements. A back side relief feature is formed on the bottom front edge of a thermal ink jet print element from a heater side during a first dicing cut, followed by a second dicing cut from a channel side of the wafer to form a front face nozzle. The back cut feature enables front face maintenance by a wiper blade or other maintenance operation, provides a pocket for excess die bonding adhesive during manufacture, and reduces front face chipping during dicing caused by the saw blade contacting the die wafer mounting media and becoming contaminated. The relief feature may be a square step feature or a beveled back cut feature and may additionally be located on a top front edge of the print element.
    Type: Grant
    Filed: May 4, 1993
    Date of Patent: April 25, 1995
    Assignee: Xerox Corporation
    Inventors: Robert P. Altavela, Lawrence H. Herko, Almon P. Fisher
  • Patent number: 5306370
    Abstract: A method of fabricating thermal ink jet printheads comprises aligning and bonding a pair of silicon wafers together, which have, on opposing confronting surface thereof, a plurality of sets of linear arrays of heating elements and associated driver circuitry on one wafer surface and a plurality of sets of parallel grooves and a communicating reservoir for each set of grooves. The grooves and reservoirs are filled with a filler material which is solid or gels at room temperature and liquid at higher temperatures. The bonded pair of wafers are severed into a plurality of individual printhead sby dicing processes conducted at room temperature. One of the dicing processes cuts the grooves in a direction perpendicular thereto in order to form concurrently the nozzle face and nozzles. The solid filler material supports fragile edges of the wafers and prevents entry of dicing debris and other contaminants. The printheads are subjected to heat, spinning, and high pressure water spray to remove the filler material.
    Type: Grant
    Filed: November 2, 1992
    Date of Patent: April 26, 1994
    Assignee: Xerox Corporation
    Inventors: Lawrence H. Herko, Robert P. Altavela, Joseph R. Weber, Robert M. White, Kathryn A. Wallace