Patents by Inventor Francis Lum

Francis Lum 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: 5959462
    Abstract: A test structure and test methodology are taught herein wherein a test structure (10) is used to test an entire integrated circuit product wafer (44). The test structure (10) has a backing support wafer (39). A die attach compound (38) is used to attach a plurality of segmented individual test integrated circuits 28-34 to the backing support wafer (39). The plurality of test integrated circuits 28-34 have a top conductive bump layer (26). This conductive bump layer (26) is contacted to a thin film signal distribution layer (14) which contains conductive interconnects, conductive layers, and dielectric layers which route electrical signals as illustrated in FIG. 2. The layer 14 also conductively connects to bumps (46) on a product wafer (44). In addition, leads (40) are coupled to conductive elements of the layer (14).
    Type: Grant
    Filed: September 8, 1997
    Date of Patent: September 28, 1999
    Assignee: Motorola, Inc.
    Inventor: Thomas Francis Lum
  • Patent number: 5707881
    Abstract: A test structure and test methodology are taught herein wherein a test structure (10) is used to test an entire integrated circuit product wafer (44). The test structure (10) has a backing support wafer (39). A die attach compound (38) is used to attach a plurality of segmented individual test integrated circuits 28-34 to the backing support wafer (39). The plurality of test integrated circuits 28-34 have a top conductive bump layer (26). This conductive bump layer (26) is contacted to a thin film signal distribution layer (14) which contains conductive interconnects, conductive layers, and dielectric layers which route electrical signals as illustrated in FIG. 2 . The layer 14 also conductively connects to bumps (46) on a product wafer (44). In addition, leads (40) are coupled to conductive elements of the layer (14).
    Type: Grant
    Filed: September 3, 1996
    Date of Patent: January 13, 1998
    Assignee: Motorola, Inc.
    Inventor: Thomas Francis Lum
  • Patent number: 4647994
    Abstract: A miniaturized tape cartridge drive for data processors in accordance with the invention has as peripherally-enclosing main frame providing an access opening for insertion to a tape cartridge and structurally mounting flat, pancake-type drive motors for tape transport and head-positioning translation laterally with respect to the tape, for accessing any of a plurality of adjacent recording tracks on the tape, such motors being disposed in tandem with respect to the cartridge-admitting opening and having their output shafts pointing in opposite directions. The head-positioning motor drives a directly-coupled rotary cam, and a positioning arm extends between the cam and the transducer head to move the head in response to movement of the cam. The positioning arm is pivotally journaled in opposite sides of the main frame upon a transverse pivot axis disposed medially of the arm, such that the arm operates as a fulcrumed lever.
    Type: Grant
    Filed: March 13, 1984
    Date of Patent: March 3, 1987
    Assignee: Irwin Magnetic Systems, Inc.
    Inventors: Samuel N. Irwin, Francis Lum, Michael L. Bolt, Steven E. Henke, Edmund L. Sokolik, John M. Chambors
  • Patent number: 4646175
    Abstract: Apparatus and method for decoding of transducer head-positioning information which has been recorded on data-storage media, in particular magnetic tape, and for use of the decoded information to position a transducer head, wherein the transducer head reads the recorded information and its output signals are sampled at predetermined times to determine their magnitude and a digital representation of such magnitude is obtained by timing an interval during which a reference source increases at a known rate from a first value to a second value whose difference corresponds to the detected magnitude of the transducer output signals. The timed interval is outputted in the form of a digital count value which is thus representative of the head-positioning information read out from the data storage media, and the digital signal provided by such count value is then used in positioning, or repositioning, the transducer head in a representative manner.
    Type: Grant
    Filed: April 5, 1984
    Date of Patent: February 24, 1987
    Assignee: Irwin Magnetic Systems, Inc.
    Inventors: Edmund L. Sokolik, Francis Lum
  • Patent number: 4586094
    Abstract: A method and apparatus for initializing a data-recording media, particularly tape, by use of the same type of media drive used for data-recording purposes, in which the actual edge of the recordable field on the media is first located by a test read/write process and the media is then transported in a succession of passes across the transducing head, during each of which the head is periodically and selectively energized to write mutually-spaced marker bursts and servo-positioning bursts, with the transducing head being moved open-loop a distance corresponding to a half-track width between each media transport. During the first such pass, the marker bursts and servo-positioning bursts are located on the basis of tape travel distance, and on successive passes burst location is determined by sensing the previously-recorded marker and servo bursts and timing-out a predetermined distance therefrom by use of an internal clock.
    Type: Grant
    Filed: March 13, 1984
    Date of Patent: April 29, 1986
    Assignee: Irwin Magnetic Systems, Inc.
    Inventors: John M. Chambors, Francis Lum
  • Patent number: 4472750
    Abstract: A recording member for digital data, particularly a recording tape, has a plurality of generally parallel, closely-spaced recording tracks which each contain pre-recorded track-identifying and transducer-positioning servo information, as well as defined data-recording areas. The pre-recorded track-identifying information preferably comprises a digitally-encoded individual track address, and the servo information comprises separate bursts used in centering the transducer upon a particular track. Preferably, each such track has a dedicated area at its beginning, end, or both, which contain continuous repetitions of such positioning information, there being no data areas in such dedicated portions. Digital encoding of track addresses utilizes binary-type code format, accomplished by defining a binary "zero" as a recorded burst present at a first number of sampling points, and defining a binary "one" as a burst present at a second number of sampling points of a second duration.
    Type: Grant
    Filed: July 2, 1981
    Date of Patent: September 18, 1984
    Assignee: Irwin Magnetic Systems, Inc.
    Inventors: Marlin K. Klumpp, Joseph H. Mueller, Francis Lum, Samuel N. Irwin
  • Patent number: 4462053
    Abstract: A method for positioning and maintaining a disc head over a desired track centerline on a disc rotatably carried on a disc drive. The distance between the current position of the disc head and the desired track centerline is monitored, and a signal generally proportional to that distance is applied to the disc head moving mechanism to cause the disc head to move toward the track centerline. The control signal is clipped if it exceeds predetermined maximum and minimum values.
    Type: Grant
    Filed: July 2, 1981
    Date of Patent: July 24, 1984
    Assignee: Irwin International, Inc.
    Inventors: Francis Lum, Bruce Graham, Samuel N. Irwin, Juan F. Velazquez
  • Patent number: D270055
    Type: Grant
    Filed: September 8, 1980
    Date of Patent: August 9, 1983
    Assignee: Irwin International, Inc.
    Inventors: Samuel N. Irwin, Otto R. Butsch, Francis Lum, Juan F. Velazquez
  • Patent number: D270348
    Type: Grant
    Filed: September 8, 1980
    Date of Patent: August 30, 1983
    Assignee: Irwin International, Inc.
    Inventors: Samuel N. Irwin, Otto R. Butsch, Francis Lum, Juan F. Velazquez