TMR and squeeze at gigabit areal densities

The track misregistration (TMR) required to achieve gigabit areal densities is calculated for a set of components based on the average bit error rate for a file. The average error rate is a statistical average, based on the TMR of the file, of the on-track and off-track error rate. The on-track and off-track error rates are dependent on squeeze from adjacent tracks. In this analysis, the average error rate is calculated using measured error rate profiles of the center track. For a file average soft error rate of 1×10^-6, the results show, for a particular head/disk combination designed for gigabit recording and operating at a linear density of 158 kbpi, that a track pitch of 4.0 μm (3.35 ktpi) can be achieved with a TMR of 0.635 μm. Obtaining this TMR value in a file is one of the challenges to recording of 1 Gb/in² in magnetic storage products