Patent ID: 6898056
Filing Date: 2005-05-24
Classification: G11B,Y10T

Abstract:
1. A thin-film magnetic head comprising: a lower core layer comprising an upper surface and a bottom surface and a first region with a predetermined thickness extending from a front end to a back end of the lower core layer and a second region behind the first region, the upper surface of the second region being lower relative to the bottom surface than the upper surface of the first region; a nonmagnetic gap layer overlying a portion of the first region of the lower core layer, with a lower magnetic pole layer therebetween; an upper magnetic pole layer having an upper surface and a back region and overlying the nonmagnetic gap layer; an upper core layer in contact with the upper surface of the upper magnetic pole layer, the upper core layer extending toward the back end of the lower core layer; a coil layer for inducing a recording magnetic field in the lower core layer and the upper core layer; and a nonmagnetic layer having an upper surface and extending from a position set back from the front end of the lower core layer over the first region and the second region of the lower core layer, wherein a contact interface between the nonmagnetic gap layer and the upper magnetic pole layer extends from the front end of the lower core layer to the nonmagnetic layer parallel to the upper surface of the first region, and a gap depth is defined within the length of the contact interface, wherein the back region of the upper magnetic pole layer extends on the upper surface of the nonmagnetic layer, and the nonmagnetic layer is located between the back region of the upper magnetic pole layer and the lower core layer, wherein the second region of the lower core layer and the upper magnetic pole layer are separated by a first distance and the first region of the lower core layer and the upper magnetic pole layer are separated by a second distance, and wherein the first distance is larger than the second distance.