Abstract
Dynamic characteristics of a magnetic head slider of a hard disk drive were analysed using 2 degrees-of-freedom (2-DOF) mechanical model considering the dynamic pressures due to the van der Waals force and the air bearing force. The corrected van der Waals force equation for multilayers and the molecular gas-film lubrication (MGL) equation were used to calculate the pressures. It was found that the signs of the total stiffness of the mechanical system could be reversed due to the negative van der Waals stiffness when the spacing became small. The spacing at which the total stiffness was zero was defined as the "stiffness reversal spacing", and the characteristics of the stiffness reversal spacing was clarified. The animations of the slider motion were shown in order to see the influence of the van der Waals force.
