Key issues in the design of magnetic tapes for linear systems of high track density

Abstract

Areal densities for data tape systems have been increasing exponentially ever since the first product introduction in the early 1950's. Increases in linear density have provided the major part of the increases in recording density. Now, however, the time has come to push harder on track densities. The signal-to-noise issues for higher track densities are relatively well understood. However, the use of full-time track following, with multi-channel heads, adds additional issues to the list of tape design objectives for future systems of very high track density. The ultimate drive error performance will now be impacted by lateral tape motion, relative azimuth angle between tape and head, and track spacing variation due to dimensional changes in the tape. Controlling lateral tape motion and relative azimuth angle requires improvements in tape edge quality, the overall tape-path design, and the writing of the original servo signals on the tape. Controlling the track spacing problem will require better understanding of tape dimensional stability and how it is influenced by environmental changes, by pack stresses, and by tape design and processing. We conclude with suggestions of how to achieve the improvements necessary to stay on the required areal density trend line.