A numerical investigation of different touchdown patterns of thermal-flying-height-control sliders

In this study we employ a numerical approach to explore the touchdown patterns of a thermal-flying-height-control (TFC) slider. Depending on the roughness of the head disk interface and thickness of the lubricant layer a TFC slider can experience different stages during touchdown. Three different touchdown patterns are shown. With a rougher interface profile the slider smoothly transfers from a flying stage to a sliding stage. With an intermediate smooth interface profile the slider experiences a flying-bouncing-sliding transition. With the smoothest interface the slider goes through a flying-bouncing-surfing-sliding transition. Different stages are characterized by different slider dynamics and slider-disk contact status. The different touchdown dynamic patterns shown here can result in a significant difference in the easiness of successful touchdown detection. The general approach proposed here may also be applied to investigate the effects of other important head disk interface factors, e.g., air bearing surface design, heater, suspension, etc. on the slider’s touchdown dynamic behaviors.