Investigation on Increase of Friction Force in Magnetic Disks with Photo Lithography Texture

Friction force between magnetic disks and magnetic heads occasionally increases to cause a hard disk drive (HDD) to lock. In this paper, we discuss the friCtion mechanism at the interface between magnetic heads and magnetic disks, which are covered by the texture surface produced on a photo lithography Process. The texture surface is homogeneously dispersed with micro lands, 3 μm in diameter and 35 nm high, with a uniform pitch. Atomic force microscope (AFM) and Auger electron spectroscopy (AES) analyses make it clear that friction force increases abruptly at a land height below approximately 24 nm, and also the land height decreases not with growing wear of the top film in micro lands but with plastic subsidence of micro lands by fatigue during contact start stop (CSS) tests and continuous sliding tests. As a result, in order to reduce the subsidence of micro lands and improve the sliding durability of the disks, the second layer below carbon protection film is hardened to the same as that on the top film