Patents by Inventor James Hsi-Tang Lee

James Hsi-Tang Lee 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: 5951880
    Abstract: A wet etching method for making calibration bump disks for use in providing quality control of production run magnetic hard disks is disclosed. It includes the steps of: (a) coating a layer of bump material on a substrate; (b) coating a photoresist layer on the layer of bump material; (c) exposing the photoresist layer to a light source under a photomask; (d) developing the photoresist layer using a developer solution to form an undeveloped photoresist layer; (e) etching the substrate containing the layer of bump material and the undeveloped photoresist layer to remove portions of the layer of bump material not covered by the undeveloped photoresist layer; and (f) stripping the undeveloped photoresist layer to leave at least a bump on the substrate which was originally covered by the undeveloped photoresist layer. The wet etching method eliminates many of the problems observed from the conventional metal mask method, including the elimination of the convex-shaped bump surface.
    Type: Grant
    Filed: May 26, 1997
    Date of Patent: September 14, 1999
    Assignee: Trace Storage Tech. Corp.
    Inventors: Chun-Jen Chen, Ming-Hung Su, Joseph C-C Hung, James Hsi-Tang Lee
  • Patent number: 5926349
    Abstract: An improved method of manufacturing is provided for making an improved merged MR head. The method employs a photoresist mask with appropriately-sized openings for simultaneously etching numerous vias to various depths over a set time period. After formation of the vias, a single photoresist mask is employed to pattern in one step gap layers G3, G2, G1 and a first shield layer S1 to the desired lateral configuration for the merged MR head. Subsequent to patterning these thin film layers, double insulation layers I2 and I3 are individually soft baked on top of the coil structure of the head followed by patterning of the layers I2/I3 by a single photoresist mask. These layers are then hard baked to retain the desired smooth configuration of the layers. The improved merged MR head has a smooth configuration to its top pole piece P2 because of the smooth configuration of the I2/I3 layer so that flux leakage and saturation problems are minimized.
    Type: Grant
    Filed: August 28, 1997
    Date of Patent: July 20, 1999
    Assignee: International Business Machines Corporation
    Inventors: Mohamad Towfik Krounbi, James Hsi-Tang Lee
  • Patent number: 5779923
    Abstract: An improved method of manufacturing is provided for making an improved merged MR head. The method employs a photoresist mask with appropriately-sized openings for simultaneously etching numerous vias to various depths over a set time period. After formation of the vias, a single photoresist mask is employed to pattern in one step gap layers G3, G2, G1 and a first shield layer S1 to the desired lateral configuration for the merged MR head. Subsequent to patterning these thin film layers, double insulation layers I2 and I3 are individually soft baked on top of the coil structure of the head followed by patterning of the layers I2/I3 by a single photoresist mask. These layers are then hard baked to retain the desired smooth configuration of the layers. The improved merged MR head has a smooth configuration to its top pole piece P2 because of the smooth configuration of the I2/I3 layer so that flux leakage and saturation problems are minimized.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: July 14, 1998
    Assignee: International Business Machines Corporation
    Inventors: Mohamad Towfik Krounbi, James Hsi-Tang Lee
  • Patent number: 5700380
    Abstract: An improved method of manufacturing is provided for making an improved merged MR head. The method employs a photoresist mask with appropriately-sized openings for simultaneously etching numerous vias to various depths over a set time period. After formation of the vias, a single photoresist mask is employed to pattern in one step gap layers G3, G2, G1 and a first shield layer S1 to the desired lateral configuration for the merged MR head. Subsequent to patterning these thin film layers, double insulation layers I2 and I3 are individually soft baked on top of the coil structure of the head followed by patterning of the layers I2/I3 by a single photoresist mask. These layers are then hard baked to retain the desired smooth configuration of the layers. The improved merged MR head has a smooth configuration to its top pole piece P2 because of the smooth configuration of the I2/I3 layer so that flux leakage and saturation problems are minimized.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: December 23, 1997
    Assignee: International Business Machines Corporation
    Inventors: Mohamad Towfik Krounbi, James Hsi-Tang Lee
  • Patent number: 5664316
    Abstract: A magnetoresistive (MR) read transducer having passive end regions separated by a central active region in which an MR layer is formed over substantially only the central active region and in which a magnetic bias layers is formed in each passive end region. Each of the magnetic bias layers includes a layer of ferromagnetic material and a layer of antiferromagnetic material overlaying and in contact with the ferromagnetic layer to provide an exchange-coupled magnetic bias field. Each of the magnetic bias layers form an abutting junction having magnetic and electrically continuity with the MR layer to produce a longitudinal magnetic bias field in the transducer.
    Type: Grant
    Filed: May 10, 1995
    Date of Patent: September 9, 1997
    Assignee: International Business Machines Corporation
    Inventors: Mao-Min Chen, Robert Edward Fontana, Mohamad Towfik Krounbi, Kenneth Ting-Yuan Kung, James Hsi-Tang Lee, Jyh-Shiliey Jerry Lo, Ching Hwa Tsang, Po-Kang Wang