Patent ID: 7551394

Claim:
A magnetic head for perpendicular magnetic recording comprising: a medium facing surface that faces toward a recording medium; a coil for generating a magnetic field corresponding to data to be written on the recording medium; a pole layer having an end face located in the medium facing surface, allowing a magnetic flux corresponding to the field generated by the coil to pass therethrough, and generating a write magnetic field for writing the data on the recording medium by means of a perpendicular magnetic recording system; a shield layer having a portion that is away from the medium facing surface and coupled to the pole layer; and a gap layer made of a nonmagnetic material and disposed between the pole layer and the shield layer, wherein: at least part of the coil is disposed between the pole layer and the shield layer and insulated from the pole layer and the shield layer; the shield layer incorporates: a first layer having an end face placed at a location in the medium facing surface forward of the end face of the pole layer along a direction of travel of the recording medium with a specific space created by a thickness of the gap layer; a second layer located on a side of the first layer farther from the pole layer and having a first surface located in the medium facing surface, a second surface touching the first layer, and a third surface opposite to the second surface; and a third layer touching the third surface of the second layer; in a cross section that intersects the end face of the pole layer and that is orthogonal to the medium facing surface and the third surface, a length of the second layer taken in a direction orthogonal to the medium facing surface is greater than a length of the first layer taken in the direction orthogonal to the medium facing surface; the third layer has an end face closer to the medium facing surface that is located at a distance from the medium facing surface; the end face of the pole layer located in the medium facing surface has a side located adjacent to the gap layer, the side defining a track width; and in the medium facing surface, a width of the end face of the first layer taken in a direction of the track width is greater than a length of the side of the end face of the pole layer located adjacent the gap layer, the magnetic head further comprising: an insulating layer made of an insulating material and disposed around the at least part of the coil; a first nonmagnetic layer made of a nonmagnetic material and disposed around the first layer; a second nonmagnetic layer made of a nonmagnetic material and disposed around the second layer; and a third nonmagnetic layer made of a nonmagnetic material and disposed between the medium facing surface and the end face of the third layer closer to the medium facing surface.