Method and apparatus for evaluating a head-disk interface condition for disk drives

摘要

A method of evaluating a condition of a head-disk interface (HDI) of an operational disk drive. The disk drive includes at least one disk having a disk surface and at least one transducer head for writing and/or reading data from the disk surface. In this regard, the transducer head is sensitive to temperature changes. With this in mind, the method includes rotating the disk at an operational rate. A first thermal signal is received from the transducer head that is indicative of thermal activity at the transducer head. The first thermal signal is analyzed for thermal transients. Based upon this analysis, first thermal variation information indicative of a relationship of thermal transients in the first thermal signal relative to a baseline is generated. Finally, the first thermal variation information is compared to threshold information indicative of an acceptable HDI. In one preferred embodiment, a prediction of an impending head crash is made based upon the comparison. Regardless, the method of the present invention does not attempt to calculate a fly height. Instead, the method essentially monitors thermal activity, and in particular thermal transients, at the transducer head. The thermal transient information is directly related to the health of the HDI and is therefore a better head crash predictor than existing methodologies.