Edge eliminated head

摘要

The authors report that the extra pulses observed in the readback signal of an inductive thin film head can be eliminated by modification of pole tip geometry. The pole surfaces of inductive film head were partially etched by ion milling to reduce the pole length to 0.7 mu m. The etched depth was adjusted to 1 mu m from the pole surface (Type I edge eliminated head). Another modification of the pole tip geometry was also performed. The pole edges were shaped canted to the read/write gap by the same ion mill etching. The angle between the gap and the pole edges was set to 27 deg (Type II edge eliminated head). In both cases of Type I and Type II edge eliminated head, the amplitude of the extra pulses in the readback signal is significantly decreased without reduction of overwrite or any other performance degradation of the head.