Patent ID: 7436627

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 through the use of a perpendicular magnetic recording system; a pole-layer-encasing layer made of a nonmagnetic material and having a penetrating groove that accommodates the pole layer; and a substrate on which the encasing layer, the pole layer and the coil are stacked, wherein: the end face of the pole layer located in the medium facing surface has: a first side close to the substrate; a second side located opposite to the first side; a third side connecting an end of the first side to an end of the second side; and a fourth side connecting the other end of the first side to the other end of the second side; the second side defines a track width; and the end face of the pole layer located in the medium facing surface has a width that decreases as a distance from the first side decreases, the magnetic head further comprising an underlying layer that is made of a nonmagnetic conductive material, touches one of surfaces of the encasing layer closer to the substrate, and has an area greater than an area of the groove.