Hang Q Ngo

US Patent:

7121133, Oct 17, 2006

Filed:

May 28, 2004

Appl. No.:

10/857195

Inventors:

Norman Chu - San Francisco CA, US
Shanlin Duan - Fremont CA, US
Patricia Galindo - Morgan Hill CA, US
Hang Fai Ngo - San Jose CA, US
Yu Lo - Foster City CA, US
Nalin Zhou - San Jose CA, US

Assignee:

Hitachi Global Storage Technologies Netherlands B.V. - Amsterdam

International Classification:

G01B 7/34

US Classification:

73 189

Abstract:

A glide head calibration technique uses two fly height calibrations on a disk media certifier. The first calibration point uses a spin down on bump technique at a first height, and the second calibration point uses a spin down on disk media roughness at a second lower height. With two height data points, a fly height curve of each glide head is approximated very accurately. Once the fly height curve is derived for each head, any fly height can be dialed-in by the disk media certifier for glide testing. This technique achieves glide fly heights between about 4 nm and 8 nm and does so with improved tolerances.

US Patent:

7164557, Jan 16, 2007

Filed:

Feb 23, 2004

Appl. No.:

10/784506

Inventors:

Parul Agrawal - Saratoga CA, US
Hang Fai Ngo - San Jose CA, US
Charles Lee - San Jose CA, US
Li-Chung Lee - Saratoga CA, US
Ullal Vasant Nayak - San Jose CA, US
Stephen Olson - Palo Alto CA, US
Robert N. Payne - San Jose CA, US
Christopher Ramm - San Jose CA, US

Assignee:

Hitachi Global Storage Technologies Netherlands BV - Amsterdam

International Classification:

G11B 5/60

US Classification:

3602362, 3602364, 3602365, 3602369, 360237

Abstract:

An air bearing burnish slider burnishes very small asperities and cleans the loose particles that adhere to the magnetic recording media. The slider applies a controllable contact force to effectively burnish disk asperities or partially attached particles. In addition, the slider cleans the loose particles effectively while flying in a stable fashion. In a low pitch design, diagonal rails push particles away from the disk surface and trailing edge pads contact the disk at lower linear velocities. Rail pads retain loose contamination and debris in their pockets and burnish asperities. Another design provides a milder burnish force and flies in a high pitch configuration. The trailing edge pads provide stable contacts and the rails help in sweeping away debris. In both designs, the contact forces can be controlled by adjusting linear velocities. A step taper at the leading edge provides a pitch-producing lift force.

US Patent:

20020162204, Nov 7, 2002

Filed:

Jan 14, 1999

Appl. No.:

09/231424

Inventors:

FRANCIS CHEE-SHUEN LEE - SAN JOSE CA, US
MICHAEL LEE MCGHEE - SAN JOSE CA, US
SALVADOR NAVARRO - HOLLISTER CA, US
ULLAL VASANT NAYAK - SAN JOSE CA, US
HANG FAI NGO - SAN JOSE CA, US

International Classification:

B24B039/00

US Classification:

029/090010

Abstract:

A method and apparatus for providing a low cost contact burnish slider is disclosed that can remain in contact or at the initial low flying heights even as the pad surfaces and leading edges wear. The burnish slider includes a body having a leading edge and a trailing edge and an air bearing surface being configured at the leading edge of the body to cut disk asperities as the slider flies and configured away from the leading edge to maintain a flying attitude wherein the leading edge is near the data recording surface and to provide restoring forces to maintain the flying attitude. The air bearing surface may include a front pad proximal to the leading edge and a rear pad distal to the leading edge. Alternatively, the air bearing surface may include two front pads proximal to the leading edge on opposite sides of the body and two rear pads distal to the leading edge and disposed on opposite sides of the body. The front and rear pad(s) extends substantially across the body of the slider. An offset pivot is provided for constraining the moment balance of the slider to provide a low pitch flying attitude. The rear pad(s) further includes a mechanical taper proximal to the trailing edge to minimize load/unload damage. The air bearing surface configuration away from the leading edge provides a force that restores the flying attitude to the slider when an impulse lifting the leading edge is encountered.