Patents by Inventor Chi Hang Kwok

Chi Hang Kwok 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).

  • Publication number: 20190067049
    Abstract: Semiconductor wafer cutting is optimised by directing a plurality of laser beams at the wafer, with the laser beams being focused so that at least some of their respective focal points are located at different depths throughout the wafer.
    Type: Application
    Filed: August 23, 2017
    Publication date: February 28, 2019
    Inventors: Chi Wah CHENG, Lap Kei CHOW, Chi Hang KWOK
  • Patent number: 8742288
    Abstract: An apparatus 101 for singulating an object is disclosed. The apparatus 101 comprises a laser 103 configured to emit a laser beam 105 with a Gaussian irradiance profile, as well as a beam-shaping device 115 configured to reshape the Gaussian irradiance profile of the laser beam 105 emitted from the laser 103. In particular, the beam-shaping device 115 has a plurality of aspherical lenses 117, 119 to redistribute irradiance of the laser beam 105, so as to reduce variation of the irradiance in an effective irradiation spectrum of the laser beam 105 for singulating the object. By redistributing the irradiance of the laser beam 105, irradiation energy may be more efficiently delivered to the semiconductor wafer 102 for laser singulation, compared with conventional laser beams with Gaussian irradiance profiles which are non-uniform. A method of singulating an object is also disclosed.
    Type: Grant
    Filed: June 15, 2011
    Date of Patent: June 3, 2014
    Assignee: ASM Technology Singapore Pte Ltd
    Inventors: Chi Hang Kwok, Chi Wah Cheng
  • Patent number: 8709916
    Abstract: A laser processing method is disclosed, comprising the steps of: directing a laser beam to a workpiece; and effecting a relative motion between the laser beam and the workpiece. In particular, the step of directing the laser beam to the workpiece comprises focusing the laser beam within the workpiece until an internal damage forms within the workpiece and a crack propagates from the internal damage to at least one surface of the workpiece to form a surface crack on the workpiece. Further, the step of effecting the relative motion between the laser beam and the workpiece is such that the surface crack on the workpiece propagates along a line of separation on the workpiece. A laser processing apparatus is also disclosed.
    Type: Grant
    Filed: July 5, 2012
    Date of Patent: April 29, 2014
    Assignee: ASM Technology Singapore Pte Ltd
    Inventors: Chi Hang Kwok, Chi Wah Cheng, Lap Kei Chow
  • Publication number: 20140011336
    Abstract: A laser processing method is disclosed, comprising the steps of: directing a laser beam to a workpiece; and effecting a relative motion between the laser beam and the workpiece. In particular, the step of directing the laser beam to the workpiece comprises focusing the laser beam within the workpiece until an internal damage forms within the workpiece and a crack propagates from the internal damage to at least one surface of the workpiece to form a surface crack on the workpiece. Further, the step of effecting the relative motion between the laser beam and the workpiece is such that the surface crack on the workpiece propagates along a line of separation on the workpiece. A laser processing apparatus is also disclosed.
    Type: Application
    Filed: July 5, 2012
    Publication date: January 9, 2014
    Inventors: Chi Hang KWOK, Chi Wah CHENG, Lap Kei CHOW
  • Publication number: 20120318777
    Abstract: An apparatus 101 for singulating an object is disclosed. The apparatus 101 comprises a laser 103 configured to emit a laser beam 105 with a Gaussian irradiance profile, as well as a beam-shaping device 115 configured to reshape the Gaussian irradiance profile of the laser beam 105 emitted from the laser 103. In particular, the beam-shaping device 115 has a plurality of aspherical lenses 117, 119 to redistribute irradiance of the laser beam 105, so as to reduce variation of the irradiance in an effective irradiation spectrum of the laser beam 105 for singulating the object. By redistributing the irradiance of the laser beam 105, irradiation energy may be more efficiently delivered to the semiconductor wafer 102 for laser singulation, compared with conventional laser beams with Gaussian irradiance profiles which are non-uniform. A method of singulating an object is also disclosed.
    Type: Application
    Filed: June 15, 2011
    Publication date: December 20, 2012
    Inventors: Chi Hang KWOK, Chi Wah CHENG
  • Publication number: 20120251105
    Abstract: A method and an apparatus are provided for launching light into an entrance facet of a MMF of an optical MMF link in a way that excites one or more targeted higher-order mode groups in the MMF. The light is launched into the entrance facet of the MMF as a line of phase-modulated spots, referred to herein as a “line launch”. The line launch causes one or more targeted higher-order mode groups to be excited in the MMF. The use of the line launch to excite one or more higher-order mode groups in the MMF increases the bandwidth of the link and allows overall link lengths to be increased. In addition, the use of the line launch is reliable and robust despite defects in the MMF and despite connector offsets. Thus, the use of the line launch ensures that a sufficient increase in link bandwidth will be achieved despite the existence of defects in the MMF and even if there is some amount of optical misalignment due to the connector being offset relative to the corresponding receptacle.
    Type: Application
    Filed: March 19, 2010
    Publication date: October 4, 2012
    Applicant: CAMBRIDGE ENTERPRISE LIMITED
    Inventors: Chi Hang Kwok, Ian Hugh White, Richard Vincent Penty, David George Cunningham