Head-disk interaction of proximity sliders studied by the acoustic emission probe, the dynamic flying height tester, and the laser Doppler vibrometer

The dynamic behavior of the head-disk interaction of two types of proximity recording sliders, a catamaran tripad and a negative pressure shaped-rail (NPS) tripad, were investigated using a combination of friction and acoustic emission (AE) measurement on a contact start/stop (CSS) tester, dynamic flying height measurement, and laser Doppler vibrometry (LDV). Interesting differences and sensitivity in the head-disk contact behavior of these two types of proximity sliders were observed for different (a) rotational speeds of the disk and radial positions of the heads on the disk, and (b) z-heights. FFT analysis applied to the unfiltered AE signal, dynamic flying height data and LDV displacement signal revealed vibration resonances of the slider body, the suspension, the air-bearing, and the disk.