Overwrite Performance Change due to Air-Flow Induced Vibration of Head Stack Assembly

Overwrite (OW) performances of two different types of head stack assemblies (HSA) were compared as a function of slider location on disks. Both HSAs have the same types of head slider, suspension interconnect, and preamplifier but have different mechanical platform and different arm structure. OW performance in the outer diameter (OD) zone is worse than the inner diameter (ID) zone by more than 2 dB for Type B HSA but not for Type A. This paper investigates the mechanism of OW degradation of Type B HSA at the OD. It was found that the mechanical vibrations owing to disk flutter and arm structure are key factors to the OW degradation.