Dynamic Characteristics of Flying Head Slider Considering Van Der Waals Forces: Analyses Based on the Corrected Van Der Waals Force Equation for Multilayers

Abstract

A dynamic model of a simple inclined flying head slider was considered in order to analyze the dynamic characteristics of a flying head slider considering the van der Waals force the air bearing force. The corrected van der Waals force equation and the linearized molecular gas-film lubrication (MGL) equation were used for the analysis. The “spacing stiffness”, kspacing, composed of the stiffnesses due to the van der Waals force and the air bearing force was defined and the flying stability of the head slider was discussed. It was found that there are flyable limit minimum spacings, and relationship between the limit minimum spacing and the disk vibration frequency (the “boundary curve of dynamic flying stability”), which provides the boundary between the stable (kspacing > 0) and unstable (kspacing < 0) domains of the flying, was presented. The basic characteristics of the flying head slider considering the van der Waals force including the dependence of the boundary curve on the film thickness of PFPE lubricant were clarified.