The Effects of Disk Surface Topography on Baseline Instability of MR Head

디스크 표면 토포그래피가 자기저항 헤드의 베이스라인 안정성에 미치는 영향

  • Published : 2000.02.01


Several factors which influence baseline instability (BLI) phenomenon in MR drive were investigated experimentally. In particular, the role of surface topography on BLI was studied in detail. The r esults show that BLI is linearly proportional to the surface waviness with a spatial wavelength of 0.4 to 5.0 min. BLI becomes worse as the surface waviness increases. On the other hand, surface roughness which has a spatial wavelength below 25 $\mu$ m has no effect on BLI. The results further show that the effect of bias current on the BLI is amplified on the disk with worse surface waviness. The disk surface waviness is dependent on the manufacturing process and becomes an inherent surface property of media. The disk surface waviness. therefore, can not be overlooked when evaluating the media for a high-performance hard disk drive. In general, waviness is reduced mainly during grinding and polishing process during manufacturing.


Hard Disk Drive;MR Head;Surface Topography;Baseline Instability;Waviness


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