Radial error propagation issues in self-servo track writing technology

Conventional servo track writing needs external devices to position heads in hard disk drives to write servo patterns. In self-servo track writing (SSTW), the position reference is regenerated from previous written tracks and a servo pattern is propagated to cover the disk in a progressive mode. Errors will propagate and compound in this process. In this paper, the radial error propagation is discussed and a containment scheme is established. Furthermore, experimental results of SSTW on a head-disk assembly with blank media and off-the-shelf electronics are analyzed to show the effectiveness of error containment in self-radial propagation.