Electromagnetic and Thermomechanical Analysis of Near-Field Heat Transfer in Heat-Assisted Magnetic Recording Heads

Abstract

Heat-assisted magnetic recording (HAMR) is a relatively new data storage technology that promises to satisfy the increasing demands for higher storage densities. Heat transfer across the nanometer-size head-disk gap does not follow classical heat transfer principles during the operation of an HAMR hard-disk drive. The HAMR technology relies on laser heating of a sub-diffraction-limit region of the magnetic medium to lower its coercivity and allow the magnetic head to write data in the form of tightly packed bits. Near-field heat transfer strongly affects the thermal protrusion produced by laser heating. A typical HAMR head model with all key components was used in a coupled electromagnetic-thermomechanical analysis to investigate the effect of near-field heat transfer on the thermal characteristics of the magnetic head. The effects of various heat sources and read/write conditions on the development of the thermal protrusion and the surface temperature distribution at the trailing edge of the slider body are examined in the context of simulation results.