Patent ID: 7796359
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 that generates a magnetic field corresponding to data to be written on the recording medium; a pole layer that has an end face located in the medium facing surface, allows a magnetic flux corresponding to the magnetic field generated by the coil to pass therethrough and generates a write magnetic field for writing the data on the recording medium by means of a perpendicular magnetic recording system; a first shield made of a magnetic material and having an end face located in the medium facing surface at a position backward of the end face of the pole layer along a direction of travel of the recording medium; a nonmagnetic layer made of a nonmagnetic material and disposed around the first shield; a first gap layer made of a nonmagnetic material, disposed between the pole layer and each of the first shield and the nonmagnetic layer, and having an end face located in the medium facing surface; a second shield made of a magnetic material and having an end face located in the medium facing surface at a position forward of the end face of the pole layer along the direction of travel of the recording medium; a second gap layer made of a nonmagnetic material, disposed between the second shield and the pole layer and having an end face located in the medium facing surface; and a substrate on which the coil, the pole layer, the first and the second shield, and the first and the second gap layer are stacked, the first shield being located closer to the substrate than is the second shield, wherein: the pole layer includes: a first portion having the end face located in the medium facing surface; and a second portion that is adjacent to the first portion and located farther from the medium facing surface than is the first portion; the second portion has a thickness greater than that of the first portion; each of the first portion and the second portion has a bottom surface that is closer to the substrate; the bottom surface of the second portion is located closer to the substrate than is the bottom surface of the first portion; the first shield has a first top surface portion that is opposed to the bottom surface of the first portion with the first gap layer in between; the nonmagnetic layer has a second top surface portion that is opposed to the bottom surface of the second portion with the first gap layer in between; and a difference in level is formed between the first top surface portion and the second top surface portion such that the second top surface portion is located closer to the substrate than is the first top surface portion.