Numerical investigation of thermal effects on a HAMR head-disk interface

Abstract

Heat-assisted magnetic recording (HAMR) is one of prospective high density recording technologies in current hard disk industry. In this paper, we incorporate HAMR optical structures into a finite element model of a thermal flying height control slider and study thermal effects of these structures on the HAMR head-disk interface. Our focus will be on the slider flying height (FH) changes due to the heat loss in the waveguide and near field transducer (NFT). According to our results, we find that large heat dissipation in NFT alone could affect the slider's FH due to the additional thermal protrusion induced around the writer. The heat dissipation in the waveguide could also influence on FH drop. In addition, the media back heating effect on the slider temperature and thermal deformation is also analysed in this paper. The numerical result shows that the respective thermal deformation caused by media back heating is about 0.09 nm with 72 nm of heat spot size. This amount could be significant when the slider's FH is below 1 nm. Therefore, it is very important to improve the efficiency of laser optical delivery system and reduce thermal effects on a HAMR head-disk interface.