Thermal Analysis for the Protrusion of Magnetic Head Available to Purchase

The thermal protrusion of a magnetic head was investigated through, first a high-resolution measurement of temperature distribution over the air bearing surface (ABS) and head coil and, second, a numerical calculation of the head protrusion. It was found that the temperature on the ABS results in a “butterfly”-shaped distribution. It was also found that an eddy current induced by high frequency write-current significantly increases the temperature of read/write elements. Moreover, the point of maximum temperature changed from the head core to the write gap when the applied current was switched from DC to AC. It was also found that a write-current induced head protrusion caused more deformation of the alumina over coat in the horizontal direction and that an ambient-temperature-induced head protrusion caused more deformation around the read-write elements. Furthermore, it is clarified that film materials with higher elastic modulus, lower expansion rate, and higher thermal conductivity reduce the head thermal protrusion. Finally, to reduce write-current-induced head protrusion, a novel thermally improved head structure is proposed.