シュミレーションによる高周波ライトヘッド設計

抄録

The frequency characteristics of the head field were studied by simulation in order to design a high-performance thin-film write head for higher frequencies. Since the 3D analysis necessary for accurate consideration of magnetic nonlinearity and eddy current takes an extremely long CPU time, we developed an advanced 2D finite element program in which the reluctance and resistivity in the head core and the gap at coils were modified by taking account of the tapered shape effect of the upper yoke. It was confirmed in several cases that the computed results given by our model were consistent with 3D calculations. The relationships between the high-frequency characteristics of the write field and both the head shape and the material properties were investigated. We showed that the larger B_sand the thicker pole film make the field larger at relatively low frequencies, and that the increase in the resistivity and the decrease in the yoke length are very effective for improving the high-frequency performances. These results can be explained by simply assuming that the highfrequency permeability decreases in proportion to the eddy current.