Patent ID: 7796361
Filing Date: 2010-09-14
Classification: G11B

Abstract:
1. 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 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; and a substrate on which the pole layer and the coil are stacked, wherein: the pole layer includes: a track width defining portion having an end face located in the medium facing surface and an end opposite to the end face; and a wide portion connected to the end of the track width defining portion; the track width defining portion has a first top surface that is a surface farthest from a top surface of the substrate; the wide portion has a second top surface that is a surface farthest from the top surface of the substrate; the second top surface has a width greater than that of the first top surface; the end face of the track width defining portion located in the medium facing surface has a first side closest to the substrate and a second side opposite to the first side, the second side defining a track width, the end face of the track width defining portion located in the medium facing surface having a width that decreases with decreasing distance from the first side; the pole layer further includes: a first side surface and a second side surface located opposite to each other in a first region that extends from the medium facing surface to a position at a distance within a range of 10 to 300 nm inclusive from the medium facing surface; a third side surface and a fourth side surface located in a second region other than the first region; a fifth side surface located at a boundary between the first region and the second region and connecting the first side surface and the third side surface to each other; and a sixth side surface located at the boundary between the first region and the second region and connecting the second side surface and the fourth side surface to each other; a distance between the first and second side surfaces taken in a direction of track width decreases with decreasing distance from a top surface of the substrate; at the boundary between the first and second regions, a distance between the third and fourth side surfaces taken in the direction of track width at a position closest to the top surface of the substrate is greater than the distance between the first and second side surfaces taken in the direction of track width at a position closest to the top surface of the substrate; and each of the fifth and sixth side surfaces has a width that increases with decreasing distance from the top surface of the substrate, the magnetic head further comprising: an encasing layer made of a nonmagnetic material and having an encasing groove that opens in a top surface thereof, and an encasing groove defining layer disposed on the top surface of the encasing layer and having a penetrating opening contiguous to the encasing groove, wherein an edge of the opening of the encasing grove defining layer is located directly above an edge of the encasing groove in the top surface of the encasing layer, and at least part of the pole layer is placed in the encasing groove of the encasing layer.