Characterization of light contact in head disk interface with dynamic flying height control

Abstract

This paper presents an investigation of the light contact in a head disk interface with dynamic flying height control. The touchdown test is conducted for a dynamic flying height control slider and the response is recorded using AE sensor. The bouncing instability and light contacts are observed during thermal actuated touching down process of the slider. The physics-based simulation is conducted to correlate with the experiments, so as to characterize bouncing instability and the factors affecting bouncing instability. The enhanced spectrogram and HHT approaches are used to extract and characterize the non-stationary characteristics of the weak signal of slider response under light contact. It is found that the light contacts are constituted by a series of intermittent transient impact responses with frequency identical to slider's pitch mode.

Relationship of Adhesion/Friction Forces and Slider Vibration in Surfing-Recording HDI System

“…Therefore, the conditions under which the surfing regime occurred at touchdown were not determined just by the frictional force. This estimation agreed with the results of some theoretical studies [5], [6].…”

“…Yu et al discussed the dynamic stability of the surfing head-disk interface using a simulation study that considered air bearings, surface adhesion, slider-lubricant, and slider-disk contacts [5]. Xu et al also conducted an analytical and experimental study of touchdown [6]. Vakis for contact with a molecularly thin lubricant layer on a rough surface in surfing recording [7].…”

Characterization of nonlinear, non-stationary, nano-scale surfing contact dynamics of TFC slider utilizing high order spectra detection

“…Traditional linear spectral analysis techniques of the vibration signals, based on autopower spectrum, are used as common tools of slider contact detection. The existing research has clarified many nonlinear dynamics phenomena including primary resonance, sub harmonics, super harmonics and fractional harmonics and combination resonance as well as internal resonance by using the FFT spectrum (Xu et al 2007;Vakis et al 2009;Canchi and Bogy 2011;Shimizu et al 2011;Bogy 2010, 2012;Sheng and Xu 2011;Hua et al 2011;Salas and Talke 2013;Xu and Sheng 2011;Hua et al 2012). Chen et al (2012) investigated distinct dynamical phases during the light touchdown between the flying head and ultra-thin Abstract In this paper, the high order spectra approach is used to determine the surfing contact dynamics signatures of thermal flight control (TFC) air bearing slider in hard disk drives.…”