Patents by Inventor Durga I. Ravipati

Durga I. Ravipati 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 magnetic head with self-aligned pole tips
    Patent number: 6487040
    Abstract: A magnetic head includes first and second pole tips separated by a nonmagnetic gap layer. The right side walls of the first and second pole tips are vertically aligned. Similarly, the left side walls of the first and second pole tips are vertically aligned. The side fringing flux is substantially reduced resulting in a magnetic head capable of writing data tracks with well defined boundaries. The fabrication of the magnetic head begins with forming a stack of layers on a substrate. The stack of layers includes a nonmagnetic layer sandwiched between the first pole tip layer and a sacrificial layer which is preferably made of a metal. A protective layer, such as alumina, is then deposited over and around the stack of layers. After planarization and ion milling, the sacrificial layer is exposed. The sacrificial layer is then etched away leaving a volume of space in the protective layer and above the gap layer. An inductive coil with associated dielectric layers are then deposited above the first pole layer.
    Type: Grant
    Filed: November 24, 1999
    Date of Patent: November 26, 2002
    Assignee: Read-Rite Corporation
    Inventors: Yun-Lin Hsiao, Lien-Chang Wang, Durga I. Ravipati, Hugh C. Hiner, William D. Jensen
  • Thin film magnetic head with self-aligned pole tips
    Patent number: 6173486
    Abstract: A magnetic head includes first and second pole tips separated by a nonmagnetic gap layer. The right side walls of the first and second pole tips are vertically aligned. Similarly, the left side walls of the first and second pole tips are vertically aligned. The side fringing flux is substantially reduced resulting in a magnetic head capable of writing data tracks with well defined boundaries. The fabrication of the magnetic head begins with forming a stack of layers on a substrate. The stack of layers includes a nonmagnetic layer sandwiched between the first pole tip layer and a sacrificial layer which is preferably made of a metal. A protective layer, such as alumina, is then deposited over and around the stack of layers. After planarization and ion milling, the sacrificial layer is exposed. The sacrificial layer is then etched away leaving a volume of space in the protective layer and above the gap layer. An inductive coil with associated dielectric layers are then deposited above the first pole layer.
    Type: Grant
    Filed: March 4, 1997
    Date of Patent: January 16, 2001
    Assignee: Read-Rite Corporation
    Inventors: Yun-Lin Hsiao, Lien-Chang Wang, Durga I. Ravipati, Hugh C. Hiner, William D. Jensen