Patent ID: 7142391

Claim:
A thin film head having a reading part and a recording part comprising: an upper magnetic pole having a first width at an air bearing surface and a second width which is larger than the first width at a first depth position from the air bearing surface; a lower magnetic pole having a lower magnetic main layer, and a projection step portion above the lower magnetic main layer; and an upper magnetic pole top layer recessed from the air bearing surface; a first coil formed between the upper magnetic pole top layer and the lower magnetic main layer; a first insulating layer covering the first coil; a non-magnetic insulating layer on the lower magnetic main layer, which is formed at an opposite side to the air bearing surface; a second insulating layer formed between the first insulating layer and the non-magnetic insulating layer; wherein the projection step portion includes one portion which faces the upper magnetic pole, and another portion which is formed so as to extend from a second depth position from the air bearing surface to a third depth position from the air bearing surface and having a part which does not face the upper magnetic pole; wherein the upper magnetic pole has a third width at a fourth depth position which is defined by a closest edge from the air bearing surface of the second insulating layer; wherein the second and third depth positions are provided between the fourth depth position and the air bearing surface; wherein a fourth width at the second depth position of the projection step portion is larger than a width in a track width direction of the projection step portion at the air bearing surface; wherein the first, second, third and fourth width are widths in the track width direction; and wherein a distance from the air bearing surface to the second depth position is shorter than a distance from the air bearing surface to the first depth position.