Study On Head Overcoatthickness Of Head Gimbal Assemblyfor Head Media Spacing Reduction
Effect of head overcoat (HOC) thickness of head gimbal assembly (HGA) for head media spacing (HMS) reduction was investigated. HOCs with thickness of 16, 20 and 24 � were used in this study. Reliability, read/write performance and active fly height were evaluated on spin-stand tester by electrical measurement at designated HGA level and wear were characterized by field-emission electron microscope. From electrical measurements that burnishing head from +1nm to -4 nm, HOC 16�shows the best reliability as degradation of read/write performance is least degradation rate, implying no significant effect to read/write performance. Furthermore, HOC 16 � has only light wear on transducers. From above results, HOC 16�is a promising thickness for HMS reduction with maintaining good reliability.
Keywords - Head Overcoat, Head Media Spacing, Head Gimbal Assembly, Electrical Degradation, FESEM