SOME HEAD DISK INTERFACE TRIBOLOGY ISSUES FOR NEAR-CONTACT RECORDING ON HARD-DISK DRIVES

As data storage densities increase and magnetic spacing decreases to ' 'near-contact'' recording, tribological issues place more stringent re quirements on tolerances for slider air bearing surfaces and disk roug hness and flatness. This is primarily because the spacing variation mu st also be reduced. In this paper we present some results of studies r elated to this problem. First we demonstrate by direct measurement tha t spacing variation is independent of flying height for a particular s lider-disk pair and that it can lead to slider-disk contacts when the mean flying height is low enough. Then we show also by measurement tha t a major part of disk curvature that leads to spacing variation is ca used by disk distortion resulting from the clamping of the disk to the spindle. Finally we present some numerical simulation results of slid er contacts with disk asperities that show the effects of disk distort ion and spacing variation.