Nano Wear of Thermal Flying Height Control Sliders

To increase the storage density in hard disk drives (HDDs), the clearance between the read/write head and the disk has to be reduced. In current HDDs, the flying height of the slider is about 1–2 nm, which is on the same order as the peak to peak value of the disk surface roughness. As a consequence, intermittent contact between the slider and the disk might occur. Intermittent head-disk contacts are undesirable since they can result in wear of the slider or lubricant transfer [1]–[5]. To achieve flying-heights of 1–2 nm, thermal flying height control (TFC) sliders have been introduced in HDDs [6]. TFC sliders contain a small heater element close to the read and write element. Energizing the heater element results in thermal expansion of the slider body and a thermal protrusion is formed. An increase in heater power increases this protrusion, thereby bringing the read and write element closer to the disk (Fig. 1).