Nonlinear dynamic effects of thermal flying-height control sliders at touch-down

The touch-down test is widely used to calibrate the flying-height (FH) of sliders by gently contacting the disk with the thermal protrusion of thermal FH control (TFC) sliders. However, the dynamic instability of TFC slider during the touch-down may significantly affect the contact detection and FH calibration. This paper highlights the nonlinear dynamics perspectives on the instability of TFC sliders during the touch-down. The mechanism of dynamic instability of TFC sliders is explored by experiments, nonlinear system models and simulations. The impact factors and air bearing surface (ABS) design considerations for minimizing the critical flying-height are also discussed.