Coupled Thermo-Mechanical Modeling of Head-Disc Interface in Heat Assisted Magnetic Recording

In Heat Assisted Magnetic Recording (HAMR), various thermal loads (laser, electrical current) subject the Head-Disc Interface (HDI) to intensive thermal strain / stress fields. The thermal strains, in terms of slider protrusion and media protrusion, significantly reduce the head-disc clearance and may lead to head-disc contact. Air bearings, by design, can passively adjust the fly height through so-called “self-compensation” to the protrusions. In this paper, an electro-thermo-mechanical model coupled with air bearing model has been developed to analyze the head flying characteristics under these thermal loads. The thermal protrusions induced by laser and current Joule heating, as well as their interactions, have been studied and verified with experimental results.