Patent ID: 8274759
Filing Date: 2012-09-25
Classification: G11B

Abstract:
1. A magnetic head for perpendicular magnetic recording, comprising: a medium facing surface that faces a recording medium; a coil that produces a magnetic field corresponding to data to be written on the recording medium; a main pole that has an end face located in the medium facing surface, allows a magnetic flux corresponding to the magnetic field produced by the coil to pass, and produces a write magnetic field for writing the data on the recording medium by means of a perpendicular magnetic recording system; a write shield that is made of a magnetic material and has an end face located in the medium facing surface; and a gap part that is made of a nonmagnetic material and interposed between the main pole and the write shield, wherein: the end face of the write shield includes a first end face portion that is located forward of the end face of the main pole in a direction of travel of the recording medium; the main pole has a top surface, and a bottom end opposite to the top surface, the top surface being a surface located at a forward end in the direction of travel of the recording medium; the top surface of the main pole includes a first portion and a second portion that are arranged in this order of increasing distance from the medium facing surface; the first portion has a first end located in the medium facing surface, and a second end opposite to the first end; the bottom end of the main pole includes a third portion and a fourth portion that are arranged in this order of increasing distance from the medium facing surface; the third portion has a first end located in the medium facing surface, and a second end opposite to the first end; assuming a first virtual plane and a second virtual plane, the first virtual plane passing through the first end of the first portion and being perpendicular to the medium facing surface and to the direction of travel of the recording medium, the second virtual plane passing through the first end of the third portion and being perpendicular to the medium facing surface and to the direction of travel of the recording medium, the first portion is inclined relative to the first virtual plane and the medium facing surface such that the second end of the first portion is located forward of the first virtual plane in the direction of travel of the recording medium, while the third portion is inclined relative to the second virtual plane and the medium facing surface such that the second end of the third portion is located backward of the second virtual plane in the direction of travel of the recording medium; the second portion and the fourth portion extend in a direction substantially perpendicular to the medium facing surface; the write shield has a first slope including a portion that is opposed to the first portion with the gap part interposed therebetween, the first slope being inclined relative to the first virtual plane and the medium facing surface; a distance between the fourth portion and the second virtual plane is greater than that between the second portion and the first virtual plane; and the first portion is smaller than each of the third portion and the first slope in length in a direction perpendicular to the medium facing surface.