Patents by Inventor Kevin P. Fahey

Kevin P. Fahey 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: 7157038
    Abstract: Patterns with feature sizes of less than 50 microns are rapidly formed directly in semiconductors, particularly silicon, GaAs, indium phosphide, or single crystalline sapphire, using ultraviolet laser ablation. These patterns include very high aspect ratio cylindrical through-hole openings for integrated circuit connections; singulation of processed die contained on semiconductor wafers; and microtab cutting to separate microcircuit workpieces from a parent semiconductor wafer. Laser output pulses (32) from a diode-pumped, Q-switched frequency-tripled Nd:YAG, Nd:YVO4, or Nd:YLF is directed to the workpiece (12) with high speed precision using a compound beam positioner. The optical system produces a Gaussian spot size, or top hat beam profile, of about 10 microns. The pulse energy used for high-speed ablative processing of semiconductors using this focused spot size is greater than 200 ?J per pulse at pulse repetition frequencies greater than 5 kHz and preferably above 15 kHz.
    Type: Grant
    Filed: December 14, 2001
    Date of Patent: January 2, 2007
    Assignee: Electro Scientific Industries, Inc.
    Inventors: Brian W. Baird, Michael J. Wolfe, Richard S. Harris, Kevin P. Fahey, Lian-Cheng Zou, Thomas R. McNeil
  • Publication number: 20020149136
    Abstract: Patterns with feature sizes of less than 50 microns are rapidly formed directly in semiconductors, particularly silicon, using ultraviolet laser ablation. These patterns include very high aspect ratio cylindrical through-hole openings for integrated circuit connections; singulation of processed die contained on semiconductor wafers; and microtab cutting to separate microcircuit workpieces from a parent semiconductor wafer. Laser output pulses (32) from a diode-pumped, Q-switched frequency-tripled Nd:YAG, Nd:YVO4, or Nd:YLF is directed to the workpiece (12) with high speed precision using a compound beam positioner. The optical system produces a Gaussian spot size, or top hat beam profile, of about 10 microns. The pulse energy used for high-speed ablative processing of silicon using this focused spot size is greater than 200 &mgr;J per pulse at pulse repetition frequencies greater than 5 kHz and preferably above 15 kHz.
    Type: Application
    Filed: December 14, 2001
    Publication date: October 17, 2002
    Inventors: Brian W. Baird, Michael J. Wolfe, Richard S. Harris, Kevin P. Fahey, Lian-Cheng Zou, Thomas R. McNeil
  • Publication number: 20020063361
    Abstract: UV laser output (190) is employed to sever a conductive shunt (106) formed across conductive components, such as read pads, of a magnetic head (10) of a slider (14) without damaging underlayers sensitive to UV laser light. An exemplary conductive shunt (106) is preferably fabricated from gold other appropriate metal(s) and forms a closed circuit with the magnetic head sensor (20) to protect it from damage from electrostatic discharge during polishing and other magnetic head processing steps. The conductive shunt (106) may be on or embedded in an alumina layer(44), permitting shunting at different workpiece layers and permitting the shunting to be present through more subsequent process steps and removed after singulation or during final assembly.
    Type: Application
    Filed: September 19, 2001
    Publication date: May 30, 2002
    Inventor: Kevin P. Fahey
  • Publication number: 20020033558
    Abstract: A UV laser (102) cuts ceramics or glasses such as the alumina or ceramic of sliders (10), and particularly separates rows (60) or sliders (10) or rounds edges (66, 82, 86). A preferred process entails covering the surfaces of wafers (50), rows (60), or sliders (10) with a sacrificial layer; removing a portion of the sacrificial layer to create uncovered zones along existing edges or over intended edges; laser cutting wafers (50) into rows (60) or rows (60) into sliders (50); laser rounding edges (66, 68, 82, 84, and/or 86), and/or corners (85 and/or 87); cleaning debris from the uncovered zones; and removing the sacrificial layer. Although a preferred laser is a Q-switched, UV solid-state laser (100) providing imaged and/or shaped output at a bite size of between about 1 to 7 &mgr;m, other lasers including excimers can be employed.
    Type: Application
    Filed: March 9, 2001
    Publication date: March 21, 2002
    Inventors: Kevin P. Fahey, Michael J. Wolfe
  • Patent number: RE43400
    Abstract: UV laser cutting throughput through silicon and like materials is improved by dividing a long cut path (112) into short segments (122), from about 10 ?m to 1 mm. The laser output (32) is scanned within a first short segment (122) for a predetermined number of passes before being moved to and scanned within a second short segment (122) for a predetermined number of passes. The bite size, segment size (126), and segment overlap (136) can be manipulated to minimize the amount and type of trench backfill. Real-time monitoring is employed to reduce rescanning portions of the cut path 112 (112) where the cut is already completed. Polarization direction of the laser output (32) is also correlated with the cutting direction to further enhance throughput. This technique can be employed to cut a variety of materials with a variety of different lasers and wavelengths. A multi-step process can optimize the laser processes for each individual layer.
    Type: Grant
    Filed: January 13, 2006
    Date of Patent: May 22, 2012
    Assignee: Electro Scientific Industries, Inc.
    Inventors: James N. O'Brien, Lian-Cheng Zou, Yunlong Sun, Kevin P. Fahey, Michael J. Wolfe, Brian W. Baird, Richard S. Harris
  • Patent number: RE43487
    Abstract: UV laser cutting throughput through silicon and like materials is improved by dividing a long cut path (112) into short segments (122), from about 10 ?m to 1 mm. The laser output (32) is scanned within a first short segment (122) for a predetermined number of passes before being moved to and scanned within a second short segment (122) for a predetermined number of passes. The bite size, segment size (126), and segment overlap (136) can be manipulated to minimize the amount and type of trench backfill. Real-time monitoring is employed to reduce rescanning portions of the cut path 112 (112) where the cut is already completed. Polarization direction of the laser output (32) is also correlated with the cutting direction to further enhance throughput. This technique can be employed to cut a variety of materials with a variety of different lasers and wavelengths. A multi-step process can optimize the laser processes for each individual layer.
    Type: Grant
    Filed: January 8, 2009
    Date of Patent: June 26, 2012
    Assignee: Electro Scientific Industries, Inc.
    Inventors: James N. O'Brien, Lian-Cheng Zou, Yunlong Sun, Kevin P. Fahey, Michael J. Wolfe, Brian W. Baird, Richard S. Harris
  • Patent number: RE43605
    Abstract: UV laser cutting throughput through silicon and like materials is improved by dividing a long cut path (112) into short segments (122), from about 10 ?m to 1 mm. The laser output (32) is scanned within a first short segment (122) for a predetermined number of passes before being moved to and scanned within a second short segment (122) for a predetermined number of passes. The bite size, segment size (126), and segment overlap (136) can be manipulated to minimize the amount and type of trench backfill. Real-time monitoring is employed to reduce rescanning portions of the cut path 112 (112) where the cut is already completed. Polarization direction of the laser output (32) is also correlated with the cutting direction to further enhance throughput. This technique can be employed to cut a variety of materials with a variety of different lasers and wavelengths. A multi-step process can optimize the laser processes for each individual layer.
    Type: Grant
    Filed: January 9, 2009
    Date of Patent: August 28, 2012
    Assignee: Electro Scientific Industries, Inc.
    Inventors: James N. O'Brien, Lian-Cheng Zou, Yunlong Sun, Kevin P. Fahey, Michael J. Wolfe, Brian W. Baird, Richard S. Harris