Flying height modulation and femto slider design

Flying height modulation (FHM), caused by disk waviness, is one of the new concerns for 3∼5 nm spaced extremely high density recording head-disk systems. This paper presents authors´ efforts on air-bearing surface (ABS) design of subambient femto sliders so as to further reduce such FHM. Results suggest that slider designs with no side pad or with side pad away from the trailing edge of the slider body will have less amount of FHM. Also sliders with reduced central pad length along the slider direction will be of reduced amount of FHM. A model is proposed to explain the above mentioned observations. The model can also be used as a design guideline in terms of reducing flying height modulation caused by disk waviness.