Characterization of magnetizing process for pre-embossed servo pattern of plastic hard disks

Rigid disks which have pre-embossed servo patterns have been developed. These media make it possible to follow tracks less than 5 /spl mu/m pitch. The substrates are made from plastic; and pre-embossed servo patterns and discrete data tracks are made by a stamping technology similar to optical disks. To generate signals from pre-embossed servo patterns, the magnetization direction of the elevated pattern and recessed area must be opposing. Therefore, a two-step magnetization method has been developed. Based on experimental results, optimum conditions are met when the magnetization transition occurs at the upper edge of the patterns.>