Visualization of lubricant pickup phenomena by lubricant thickness mapping on slider surface

A slider surface analyzing tester was developed to observe the lubricant thickness distribution on a slider surface by interferometry. We observed three phenomena related to lubricant pickup by the slider. The picked-up lubricant gathered around the boundary of the pad and recess area during the unloading interval, and the gathered lubricant flowed to the trailing edge of the pad after loading on the disk surface. There were two lubricant flows on the pad surface. The first was a circulation flow from the dynamic flying height protrusion area to the leading edge of the pad. The second was a circulation flow from the lubricant pool to the leading edge of the pad. Lubricant dewetting occurred on the slider pad surface when a thick layer of lubricant was adhered to the pad surface.