Patent ID: 6525904
Filing Date: 2003-02-25
Classification: G11B

Abstract:
A thin film magnetic head comprising:two magnetic layers magnetically coupled to each other having two magnetic poles which face each other with a gap layer in between and face a recording medium, a thin film coil provided between the two magnetic layers, and an insulating layer for insulating the thin film coil from the two magnetic layers, wherein at least one of the two magnetic layers includes: a first magnetic layer portion extending from a recording-medium-facing surface facing the recording medium to or near to an edge of the insulating layer on the side of the recording-medium-facing surface and having a constant width for defining a write track width on the recording medium; a second magnetic layer portion magnetically coupled to the first magnetic layer portion at a first coupling portion located at or near the edge of the insulating layer; a third magnetic layer portion magnetically coupled to the second magnetic layer portion at a second coupling portion on the side of the second magnetic portion opposite to the first coupling portion; and a fourth magnetic layer portion magnetically coupled to and overlapping at least a part of the first magnetic layer portion, the second magnetic layer portion or the third magnetic layer portion, the fourth magnetic layer portion having a larger width and area than the width and area of the third magnetic layer portion, wherein a step along the width is formed at the first coupling portion so that the width of the first magnetic layer portion at the first coupling portion is smaller than the width of the second magnetic layer portion at the first coupling portion, a step along the width is formed at a second coupling portion so that the width of the second magnetic layer portion at the second coupling portion is smaller than the width of the third magnetic layer portion at the second coupling portion, and the first magnetic layer portion, the second magnetic layer portion and the third magnetic layer portion are integrally formed by the same step, and the fourth magnetic layer portion is formed as a separate part by a different step from the step of forming the first magnetic layer portion, the second magnetic layer portion and the third magnetic layer portion.