Thin-film inductive heads for perpendicular recording

A modified thin-film magnetic head for perpendicular recording in rigid disk drives with improved read/write characteristics, especially at high areal bit densities, is presented. The head on which the modified design is based is described. It combines the advantages of single-pole heads and thin-film heads, writing with the sharp field edge of the leading pole and reading like a thin-film head. To increase the writing efficiency and improve the yield, the sequence of magnetic layers in the head is changed; the second layer of the four-layer head is embedded in the substrate, where it can be placed much closer to the pole tip of the first layer. The improved write capability depends mainly on the position of the embedded layer. In addition, there results an improved magnetic flux guidance from the embedded layer into the pole tip layer, providing the potential for a significant improvement in fabrication yield. The embedded-layer approach also allows a further increase in areal density. The results of read/write tests and the write-wide and read-narrow characteristics are presented