Patents by Inventor Lian-Cheng Zou
Lian-Cheng Zou 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).
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Patent number: 7157038Abstract: 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: GrantFiled: December 14, 2001Date of Patent: January 2, 2007Assignee: Electro Scientific Industries, Inc.Inventors: Brian W. Baird, Michael J. Wolfe, Richard S. Harris, Kevin P. Fahey, Lian-Cheng Zou, Thomas R. McNeil
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Publication number: 20060091126Abstract: 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: ApplicationFiled: November 15, 2005Publication date: May 4, 2006Inventors: Brian Baird, Michael Wolfe, Richard Harris, Kevin Fahey, Lian-Cheng Zou, Thomas McNeil
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Patent number: 6676878Abstract: 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 &mgr;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 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.Type: GrantFiled: June 6, 2002Date of Patent: January 13, 2004Assignee: Electro Scientific Industries, Inc.Inventors: James N. O'Brien, Lian-Cheng Zou, Yunlong Sun
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Publication number: 20020190435Abstract: 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 &mgr;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 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.Type: ApplicationFiled: June 6, 2002Publication date: December 19, 2002Inventors: James N. O'Brien, Lian-Cheng Zou, Yunlong Sun
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Publication number: 20020149136Abstract: 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: ApplicationFiled: December 14, 2001Publication date: October 17, 2002Inventors: Brian W. Baird, Michael J. Wolfe, Richard S. Harris, Kevin P. Fahey, Lian-Cheng Zou, Thomas R. McNeil
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Patent number: RE43400Abstract: 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: GrantFiled: January 13, 2006Date of Patent: May 22, 2012Assignee: 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
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Patent number: RE43487Abstract: 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: GrantFiled: January 8, 2009Date of Patent: June 26, 2012Assignee: 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
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Patent number: RE43605Abstract: 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: GrantFiled: January 9, 2009Date of Patent: August 28, 2012Assignee: 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