Effect of slider lubricant pickup on stability at the head-disk interface

As the flying height in hard disk drives is reduced below 5 nm, a variety of factors such as intermolecular forces, lubricant modulation and meniscus forces affect the ability of the slider to fly stably over the disk. The presence of these forces leads to a dynamic instability. Identification of these forces is important for achieving the necessary interface for the areal density goal of 1 Tb/in². To achieve this identification we conducted touchdown-takeoff tests at different humidities and for different slider-disk combinations. It was found that lubricant pickup by the slider leads to lubricant mediated adhesion. This also contaminates the slider air-bearing surface, increases slider-disk adhesion, and decreases the flying stability of the slider.