EDGE ELIMINATED HEAD

The extra pulses observed in the readback signal of an inductive thin film head were found to be eliminated by adequate modification of pole tip geometry. The pole surfaces of inductive thin 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). We also performed another modification of the pole tip geometry. The pole edges were shaped canted to the read/write gap by the same ion mill etching. The angle between the gap and the pale edges was set to 17deg (Type II Edge Eliminated Head). In both cases of Type I and Type II of the 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. The improved readback pulse of the Edge Eliminated Head was satisfactorily equalized to adapt to a class IV partial response read channel.