磁気記録装置ヘッド・媒体インタフェースにおける熱点温度推定法(第1報)

表面温度推定式の導出

抄録

The feasibility is investigated of estimating the flash temperature of intermittent magnetic head/media contacts using the output of a magnetoresistive (MR) micro-sensor embedded in the head. On the assumption that a uniform square heat source moves on the head surface at a high speed, an apporoximate relationship between the surface temperature rise and the sensor output change is presented by applying the profile method in heat conduction theory. In order to calculate the surface temperature using this relationship, it is necessary to know the heat source width. In this paper, the width is assumed to be equal to its length that can be observed from the sensor output increasing duration. A finite difference numerical simulation is performed to verify the estimation accuracy of this method for different sensor heights in the range from 2.5 to 20 L' m. The influences of the thermal properties of the sensor surrounding material are also made clear. As a result, in the case of MR sensor NiFe and its surrounding material A1₂O₃-TiC, the surface temperature can be estimated with an accuracy of about 10% for sensors of less than 10 u- m high and a heat source duration more than 0.5μs.