Prediction of drive level flying-height distribution based on drive component variations

摘要

The flying height of a slider in an assembled disk drive is, in general, different from that measured for the same part on a spin stand, because it is affected by a part-to-part variation of the many components that comprise the drive, and also by drive operating conditions including the actuator seeking motion. In this paper a statistical method that can properly account for after-shipping field altitude distributions and measured non-Gaussian component variations is presented and evaluated. A method to determine the effect on flying height caused by the actuator seeking motion in the drive is also presented and evaluated. The combined use of these two methods leads to drive level flying-height predictions that are more representative of field conditions and less pessimistic than root-mean-squared combination methods.