Patents by Inventor Ka Chi Wong

Ka Chi Wong 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).

  • Thin film delamination detection for magnetic disks
    Patent number: 6580266
    Abstract: An apparatus and method for detecting and marking delamination defects on thin film disks are disclosed. The apparatus includes a read/write (R/W) head and a burnishing head mounted on separate arms that access the disk while spinning on the test stand. The controller uses the R/W head to perform an initial magnetic test of selected areas on the disk to establish an initial defect map. The burnish head is then flown over the surface for an extended time to accelerate and open up the latent delamination defects by impacting protruding material. The R/W head is then used to perform a second magnetic test which is compared against the first test to identify the delamination defects which have been developed by the burnishing. The delamination defects are then marked with a magnetic pattern which aids in optically locating the defect during subsequent failure analysis.
    Type: Grant
    Filed: November 2, 2001
    Date of Patent: June 17, 2003
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Bradley Frederick Baumgartner, Shanlin Duan, Yan Liu, Bob C. Robinson, Li Tang, Ka Chi Wong
  • Thin film delamination detection
    Publication number: 20030107830
    Abstract: An apparatus and method for detecting and marking delamination defects on thin film disks are disclosed. The apparatus includes a read/write (R/W) head and a burnishing head mounted on separate arms that access the disk while spinning on the test stand. The controller uses the R/W head to perform an initial magnetic test of selected areas on the disk to establish an initial defect map. The burnish head is then flown over the surface for an extended time to accelerate and open up the latent delamination defects by impacting protruding material. The R/W head is then used to perform a second magnetic test which is compared against the first test to identify the delamination defects which have been developed by the burnishing. The delamination defects are then marked with a magnetic pattern which aids in optically locating the defect during subsequent failure analysis.
    Type: Application
    Filed: December 7, 2001
    Publication date: June 12, 2003
    Inventors: Bradley Frederick Baumgartner, Shanlin Duan, Yan Liu, Bob C. Robinson, Li Tang, Ka Chi Wong
  • THIN FILM DELAMINATION DETECTION
    Publication number: 20030085701
    Abstract: An apparatus and method for detecting and marking delamination defects on thin film disks are disclosed. The apparatus includes a read/write (R/W) head and a burnishing head mounted on separate arms that access the disk while spinning on the test stand. The controller uses the R/W head to perform an initial magnetic test of selected areas on the disk to establish an initial defect map. The burnish head is then flown over the surface for an extended time to accelerate and open up the latent delamination defects by impacting protruding material. The R/W head is then used to perform a second magnetic test which is compared against the first test to identify the delamination defects which have been developed by the burnishing. The delamination defects are then marked with a magnetic pattern which aids in optically locating the defect during subsequent failure analysis.
    Type: Application
    Filed: November 2, 2001
    Publication date: May 8, 2003
    Inventors: Bradley Frederick Baumgartner, Shanlin Duan, Yan Liu, Bob C. Robinson, Li Tang, Ka Chi Wong