Low friction sliding hard disk drive system

摘要

A operationally contacting hard disk drive system has reduced friction due to lower capillary adhesion between the disk surface and a transducer in a substantially continuous sliding relationship with the surface. The disk surface has an adhesion-reducing texture that includes a microscopic RMS roughness in a range between about 1.5 and 5.5 nanometers, or a number of asperities having a mean plane to peak height in a range between about 6 and 50 nanometers. The roughness may increase in a radially graded fashion to compensate for the increased linear velocity and concomitant frictional power loss near the outer diameter of the disk. It is important that the uppermost reaches of the textured surface are smooth but not flat in order to obtain lasting low friction operation, which is accomplished by constructing the surface with a highest approximately one percent having an average radius of curvature in a range between 2 microns and 100 microns. An area of the slider in apparent contact with the disk surface is preferably less than 1000 square microns, and a ratio between this nominal area and the mean to peak height is less than 0.3 meters. The slider may also include a substantial thickness of partially wetting material in contact with the disk, or may alternatively be textured with deep grooves or materials having differing wear rates, in order to provide reduced frictional adhesion despite wear of the slider.