Embossed disks with discrete magnetic tracks and servo marks are proposed and evaluated. The tracks and the servo marks are made by etching the glass substrate. The guard band depth was decided to be 0.2 µm. Using the disks, the head positioning accuracy of 0.09µm (rms) and the recording density of 192 tracks per millimeter were demonstrated.

A dynamic measurement method of static R/W skew caused by MR-Inductive element alignment error is discussed. A geometrical model for the displacement between a write gap and a read gap on a swing arm is formulated. A measurement method wthich employs read-after-write procedure on disk surfaces in a drive is proposed. A simulation results is reported. It contributes to increase the track densities of HDDs using MR/Inductive heads in the region of more than 200 TPMM (5000 TPI).