Maximum writing cycle control and disk lubricant and overcoat robustness of hybrid HAMR disk drives

This paper reported authors' efforts in exploring proper drive configurations and file management schemes to significantly enhance the thermal robustness of the disk lubricant and overcoat of the heat assisted magnetic recording (HAMR) disk drives. Results suggest that hybrid drive with proper file management schemes can significantly reduce the maximum number of HAMR writing operations over any specific track or sector of the HAMR disk drives. In fact, the number of writing operations at any specific disk surface location could be reduced to 104 level (areal density: 1.5 Tb/in
²
, bit aspect ratio: 3) which make the development of HAMR disk overcoat and lubricant much easier. Experimental results indicate that lubricant depletion depth can be less than 20% of the total lube thickness even for continuous writing operations over the same track and for 104 writing cycles (revolutions). Similar observation on disk carbon overcoat can be made as well.