Dynamic Numerical Simulation of Lubricant Behavior at the Head Disk Interface

The lubricant contamination and migration on the flying head slider surface in hard disk drives are studied in this paper. The lubricant dynamics is modeled based on the continuum thin film lubrication theory with inter-molecular forces. We investigate the detailed lubricant behavior on a modern negative-pressure type flying slider. We find distinct lubricant migration speeds depending on the etch depth of the slider surface and the accumulation of lubricant at specific regions. We also find that lubricant behavior largely correlates with the magnitude and direction of the air bearing shear stress.