Hard Disk Drive Reliability Modeling and Failure Prediction

A reliability model for the hard disk drive (HDD) is developed, focusing on head-disk separation as the primary independent variable. Among the many factors contributing to reliability, the role of water vapor is described for the first time. An experimental method based on magnetic spacing loss theory is used to characterize the head-media separation as a function of temperature, altitude, humidity, and HDD operating mode. A statistical model based on these empirical data is developed to predict HDD reliability for various operating conditions. The predictive capability of the model is verified experimentally through application to HDD product reliability test data.