Patent ID: 6999275

Claim:
A thin film magnetic head comprising a lower core layer, a bottom pole layer formed on the lower core layer separately therefrom or integrally therewith, a nonmagnetic gap layer formed on at least the bottom pole layer, an upper core layer to be joined to the top of the gap layer at a surface facing a recording medium, and a coil layer formed behind the bottom pole layer in the height direction, for inducing a recording magnetic field in the lower core layer and the upper core layer; wherein the upper core layer comprises a tip region exposed with a track width at the surface facing the recording medium, and a rear end region extending backward from the end edge of the tip region in the height direction so that the width dimension in the track width direction gradually increases in the height direction; wherein the space between the tip region of the upper core layer and the bottom pole layer comprises a portion extending backward from the surface facing the recording medium in the height direction, in which only a gap layer is present, and a gap depth is regulated by the end edge of the portion, and a portion extending backward from the end edge in the height direction, in which a partial insulating layer, formed on the bottom pole layer through the gap layer or directly on the bottom pole layer, is present together with the gap layer or with the gap layer removed so that the gap between the tip region of the upper core layer and the bottom pole layer in the portion comprising the partial insulating layer is larger in the track width direction than the gap in the portion comprising only the gap layer; wherein the length dimension of the bottom pole layer from the surface facing the recording medium in the height direction is about 0.5 μm to about 3.0 μm; wherein the gap depth is regulated by the distance between the bottom of the medium-facing surface-side end of the partial insulating layer and the medium-facing surface, the tip region of the upper core layer being formed to extend from a front end of the gap layer to the partial insulating layer; and wherein a first insulating layer is formed between the bottom pole layer and the lower core layer, the partial insulating layer being formed on the bottom pole layer and the first insulating layer through the gap layer.