Thermal protrusion induced air bearing frequency variations

The thermal flying height control sliders are widely used in hard disk drives. This paper studies the relationship between the air bearing frequencies and the thermal protrusion values of a thermal flying height control slider by simulation. Simulation results show that the second pitch mode of the slider increases significantly as the thermal protrusion increases. This feature could be used to in situ monitor the thermal protrusion values and the flying heights of the slider. Discussions on all the air bearing frequency modes are given, and the reasons of the frequency variations due to thermal protrusion are explained in details.