Patents by Inventor Jiann-Chang Lo

Jiann-Chang Lo 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: 5626276
    Abstract: An ultrasonic wirebonding assembly, consisting of an actuator producing vibrations at an ultrasonic frequency and a tip transmitting such vibrations to a bonding wire atop a terminal to which the wire is to be bonded, is moved among positions on a circuit chip where wirebonding operations are to occur by means of a linkage. The linkage consists of first and second drive arms, each of which is pivoted on a single stationary shaft, a drive link pivoted on the second drive arm, and a connecting link extending between the drive link and the first drive arm, being pivoted at each end. Each arm is independently driven using a motor having a coil moving over an arcuate permanent magnet. The wirebonding assembly is driven vertically, downward in a direction of engagement with the workpiece and upward in a direction of disengagement with the workpiece, on the drive link by means of a linear motor.
    Type: Grant
    Filed: March 14, 1996
    Date of Patent: May 6, 1997
    Assignee: International Business Machines Corporation
    Inventors: Jiann-Chang Lo, Michael Servedio
  • Patent number: 5550483
    Abstract: Probing system performance is improved by dynamically positioning a test probe at a test site during the gantry settling interval using a high performance secondary positioner to compensate for the inherent moving mass oscillational displacements. A primary positioner positions the gantry and its associated test probe to within a predetermined axis distance of the test site and a secondary positioner dynamically maintains the test probe at a target position corresponding to the test site during the settling interval by imparting compensating displacements to the test probe to counteract the displacement errors incurred as the primary positioner attempts to settle the gantry at the test site. Similarly, automatic machine tool performance is improved by dynamically positioning a work tool at a work site during the gantry settling interval using a high performance secondary positioner to compensate for the inherent moving mass oscillational displacements.
    Type: Grant
    Filed: November 18, 1994
    Date of Patent: August 27, 1996
    Assignee: International Business Machines
    Inventors: James E. Boyette, Jr., James M. Hammond, Jiann-Chang Lo, James C. Mahlbacher, Michael Servedio, Ali R. Taheri
  • Patent number: 5543726
    Abstract: A system for probing both sides of a high density printed circuit board includes an open frame extending around the circuit board when it is held in a test position by a circuit board carrier. The frame includes two parallel rail structures extending above, and at opposite ends of, the circuit board in the test position. The frame also includes another two parallel rail structures extending below, and at opposite ends of, the circuit board. The upper and lower rail structures extend perpendicularly to one another, and are fastened together at the corners of the frame by means of compression bolt assemblies. Two gantry structures are moved in a first direction between the upper rail structures, while two other gantry structures are moved in a direction perpendicular to the first direction between the lower rail structures. A carriage moves along each gantry structure, and a probe is mounted on each carriage to be moved toward and away from the adjacent surface of the circuit board.
    Type: Grant
    Filed: January 3, 1994
    Date of Patent: August 6, 1996
    Assignee: International Business Machines Corporation
    Inventors: James E. Boyette, Jr., Jiann-Chang Lo, Michael Servedio
  • Patent number: 5532611
    Abstract: Disclosed is a Probe Positioning Actuator which is low in cost and mass, capable of high accelerations, relatively long stroke and compact packaging, as well as high in efficiency. The actuator assembly comprises a frame, and at least one pair of spaced apart, laterally extending, conductor carrying, flexible beams attached to the frame. A non-magnetic armature, substantially U-shaped in cross section, is attached adjacent or approximate the extended terminal ends of the beams, and a probe is attached to the base of the "U" of the armature for contacting selected points in the electrical circuit associated with the device being tested. The heart of the actuator includes a coil mounted on the upstanding legs of the U-shaped armature and arranged so that the axis of the coil is perpendicular to the base of the armature but substantially parallel to the probe tip.
    Type: Grant
    Filed: May 26, 1995
    Date of Patent: July 2, 1996
    Assignee: International Business Machines Corporation
    Inventors: Jiann-Chang Lo, Michael Servedio, James M. Hammond, James E. Boyette, Jr., Hans-George H. Kolan
  • Patent number: 5528033
    Abstract: A method for automatically providing a surface profile analysis of a submicron device using a microscope system typically used to measure critical dimensions of the submicron device is disclosed. The method generates a data point array that is linearly interpolated along a particular scan line measured. The system then calculates an angle for performing a rotational correlation then rotates the measurement profile from the scan line to an absolute horizontal position based on this rotational correlation angle. Next, the system separates the scan line into independent subset features having line and trench features. The number of these line and trench features are then determined in the scan line and using the data point array, the system then calculates the height, width, and angle for each subset feature in that scan line.
    Type: Grant
    Filed: March 29, 1995
    Date of Patent: June 18, 1996
    Assignee: International Business Machines Corporation
    Inventors: Jiann-Chang Lo, Timothy J. O'Leary