Thermal asperities (TA’s) are tribological events that cause repercussions for giant magnetoresistance (GMR) and MR heads in the hard disk drive industry. A TA is a read signal spike caused by sensor temperature rise due to contact with disk asperities or contaminant particles. TA events may cause GMR and MR heads to temporarily lose their reading capability, and may potentially damage the transducer. It is difficult to completely avoid particle contamination in hard drive applications. Hence it is necessary to design heads/media with a minimum TA sensitivity to particles. A test method for TA sensitivity to particles is needed. This work developed a test method for TA sensitivities to particles. The test system includes a CSS tester with TA detection capability, a chamber to contain the head/disk interface, a particle atomizer, and a particle counter. Aluminum silicate particles used in the test have sizes ranging from 0.2 to 1.0 μm. Particles are injected into the chamber during head scan for TA’s from ID to OD with adjustable air-borne concentrations in the chamber from to TA counts of 30 scans are averaged to obtain reliable TA sensitivity data. Media with different lubricant thickness, different carbon overcoats, and different lubricant types are tested with this method. The results indicated that this methodology can effectively differentiate TA sensitivity to particles for the media studied.
Thermal Asperities Sensitivity to Particles: Methodology and Test Results
Contributed by the Tribology Division of THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS for presentation at the STLE/ASME Tribology Conference, Seattle, WA, October 1–4. Manuscript received by the Tribology Division Feb. 15, 2000; revised manuscript received June 16, 2000. Paper No. 2000-TR1B-14. Associate Editor: J. L. Streator.
- Views Icon Views
- Share Icon Share
- Cite Icon Cite
- Search Site
Wang, L. Y., Sullivan , M., and Chao, J. (June 16, 2000). "Thermal Asperities Sensitivity to Particles: Methodology and Test Results ." ASME. J. Tribol. April 2001; 123(2): 376–379. https://doi.org/10.1115/1.1308002
Download citation file:
- Ris (Zotero)
- Reference Manager