Topographical wear characterization of magnetic heads using a coupled acoustic emission sensor and friction sensor

Abstract

Device characterization and reliability analyses of magnetic heads have never been more important in HDD industry now that the spacing between the head and disk is overly minimized to few nanometers. New head prototypes have to be characterized to verify the design and evaluate their performance. Topographical wear test is used to characterize the spacing performance of the designs by examining the wear pattern produced on the heads. In this study, a different approach of systematically producing controlled wear on heads is introduced. The method uses both AE and friction sensors to determine the needed over push power to be applied to effectively wear the magnetic heads. The method is then used to characterize the robustness, understand the head-disk interaction dynamics and map out the wear locations of the head samples.