Effect of Vapor Lubrication on Head–Disk Clearance and Slider Wear in Inert Gas Environments

Abstract

The application of dynamic flying height (DFH) control technology to hard disk drives (HDDs) reduces the clearance of the magnetic heads above the disk surface to a few nanometers. Further, such a small clearance distance sometimes causes wear of the diamond like carbon (DLC) overcoat on the slider surface at the head–disk interface (HDI) owing to contact with the disk surface. The wear mechanisms of the DLC overcoat are considered to be either mechanical wear or tribochemical wear (oxidation of carbon) [1]. Recently, a helium-filled HDD was developed to improve the storage capacity and power consumption of HDDs. In the helium-filled HDD, tribochemical wear does not occur because there is no oxygen in the HDD. In addition, there is no humidity (water vapor), which was found to affect wear at the HDI [2]. Therefore, it is important to understand the effect of humidity and an oxygen-free inert gas environment on slider wear.