Abrasion testing was performed on DC sputtered hydrogenated carbon films on commercial thin-film disks processed under several conditions. Four film characteristics were found to influence the abrasion resistance of the disk, i.e., roughness, film adhesion, carbon toughness, and coefficient of friction. It was found that both fine-scale surface topography from the sputtered layer and substrate texture degraded abrasion resistance. Excellent abrasion resistance was observed for carbon films as thin as 10 nm on polished substrates when the magnetic film topography was minimized. Film adhesion was degraded by exposure to temperature and humidity. Hydrogen incorporation into the carbon films reduced film hardness which degraded abrasion resistance. The lifetime of resistive heaters in thermal printing heads is mainly determined by the continuous abrasion due to the mechanical contact with the sliding paper. The thick film resistor materials used are not specifically developed for abrasion resistance; therefore protective coatings were applied to the resistor surface in order to enhance the long-term performance of the printing head. The optimum abrasion resistance was achieved with a diamond-like carbon coating but, in this paper, standard coatings are also investigated, since they are interesting from an economical point of view.
