Assessment of the risk imposed by the presence of corroded shallow voids on the initialization and long-term reliability of hard disk drives

This paper investigates how corrosion growth that originates from shallow film voids on thin film sputtered magnetic media can impact the final HDD system performance. The impact of shallow void corrosion (Dai et al. IEEE Trans Magn 46:92, 2010) in HDD system can be both on its behavior during initialization i.e. servo write formatting and initial defect mapping, and on its long term reliability. One of the main concerns for HDD reliability due to media is the occurrence of a condition called metallic smear. Metallic smear is a contamination of the head-pole area that causes an unstable fly height condition. Metallic smear is possibly caused by media corrosion and therefore void corrosion is a logical concern. However, our study shows that shallow void corrosion is not associated with metallic smear risk and does not contribute to HDD initialization failures.