Fly Height, Pitch, and Crown Measurements of Hard-disk Sliders by Capacitance Stripe

Abstract

The capacitance-stripe technique uses a special disk and high-speed capacitance amplifier to yield profiles of the air-bearing surface of a flying slider. Herein are reported extensions of the technique to make it more applicable to modern low-flying sliders. These include • more planar substrate, an amplifier less sensitive to large lead impedances, and the use of a difference measurement to account for the non-uniform rail-widths of some modern sliders. Results of fly height, pitch, and crown measurements are close enough to interferometric measurements of these quantities to encourage the use of capacitance stripe as a low-cost alternative technique. Landing measurementson an IBM 3390-type slider show the slider tipping forward on landing owing to frictional torques. © 1992 IEEE