Patent ID: 6965495

Claim:
A thin film magnetic head comprising: a lower core layer extending from a surface facing a recording medium in a height direction; a protruding layer extending on the lower core layer for a predetermined length from the surface facing the recording medium in the height direction; a back gap layer disposed on the lower core layer separated from a rear end of the protruding layer by a first distance in the height direction; a coil layer disposed in a space surrounded by at least the lower core layer, the protruding layer and the back gap layer; a coil insulating layer covering the coil layer, tops of the coil insulating layer, the protruding layer and the back gap layer being planarized to a continuous flat surface; a Gd-determining layer disposed on the flat surface separated from the surface facing the recording medium by a second distance in the height direction. a lower magnetic pole layer and gap layer disposed in that order on the flat surface in each of a region between the surface facing the recording medium and the Gd-determining layer and a region behind the Gd-determining layer in the height direction; and an upper magnetic pole layer disposed on the gap layer and the Gd-determining layer; wherein the lower magnetic pole layer, the gap layer and the upper magnetic pole layer have a same planar shape, and a track width is determined by a width of the upper magnetic pole layer in a track width direction at the surface facing the recording medium.