Title :
The role of disk surface waviness on baseline instability of MR head
Author :
Yim, Pyongwon ; Wang, Ping ; Li, Zhaohui ; Danen, Todd ; Choa, Sunghoon ; Lee, Hyung Jai
Author_Institution :
HDD R&D Centre, Samsung Inf. Syst. America, San Jose, CA, USA
fDate :
3/1/1999 12:00:00 AM
Abstract :
To investigate the role of disk surface waviness on the baseline instability (BLI) of the read-back signals from MR head, we measured the average height of surface waviness with a spatial wavelength of 0.4 to 5.0 mm using a white light interferometer instrument. We used an MR head over four sets of media to measure the baseline instability at OD and at MD. The results show that the baseline instability becomes worse as the surface waviness increases and that the baseline instability is linearly proportional to the surface waviness. The result further shows that the effect of bias current on the baseline instability is amplified on the disk with worse surface waviness. The surface waviness, therefore, can not be overlooked when evaluating the media for a high-performance hard disk drive
Keywords :
hard discs; light interferometry; magnetic heads; magnetoresistive devices; surface topography; baseline instability; disk surface waviness; hard disk drive; magnetoresistive head; readback signal; white light interferometry; Fluctuations; Frequency; Hard disks; Magnetic heads; Rough surfaces; Surface roughness; Surface waves; Temperature; Voltage; Wavelength measurement;
Journal_Title :
Magnetics, IEEE Transactions on