Analysis of thermal flying-height control slider in a hard disk drive under humid air condition

Thermal flying-height control (TFC) technology is now widely applied in the hard disk drive (HDD) industry, because it enables consistent read/write spacing, increases storage density and improves HDD reliability. In a TFC slider, the air bearing pressure at the transducer area can be raised to ten or fifteen times the ambient pressure and it can decrease the air bearing pressure. This paper investigates the effect of humid air condition in TFC slider. It is found that because of the high pressure in transducer area of slider, the water molecules are condensed and the air bearing pressure is changes. Therefore, the slider cannot maintain the flying attitude and the flying-height is changed. Moreover, the change of air pressure causes the change of heat transfer coefficient between slider and air bearing. Consequently, it causes a change of the performance in TFC slider. And in higher humidity and temperature, the effect is intensified.