Patent ID: 7310203

Claim:
A thin film magnetic head comprising: an upper magnetic pole; and a lower magnetic pole facing the upper magnetic pole through a gap layer, wherein when a track width direction is defined as an x-axis direction, a direction orthogonal to an air bearing surface (ABS) is defined as a y-axis direction, and a direction orthogonal to the x-axis direction and the y-axis direction is defined as a z-axis direction, the upper magnetic pole is configured so that a first upper pole portion which has a thickness of a track width Tw in the x-axis direction extends in the y-axis direction from the ABS to a height Ly, and a second upper pole portion has a width equal to or wider than Tw in the x-axis direction at a height equal to or higher than Ly in the y-axis direction, the lower magnetic pole is configured so that a first lower pole portion which has a thickness of the track width Tw in the x-axis direction extends in the y-axis direction from the ABS to a height Tp, and a second lower pole portion has a width equal to or wider than Tw in the x-axis direction at a height equal to or higher than Tp in the y-axis direction, said second lower pole portion having the width equal to or wider than Tw in the x-axis direction being formed up to a height Gd in the y-axis direction, said first lower pole portion having the thickness of the track width Tw in the x-axis direction being provided up to a predetermined height in a direction opposite to said upper magnetic pole from a portion contacting with said gap layer, and being configured to have a width equal to or wider than Tw in the x-axis direction at a height equal to or higher than said predetermined height, and the thin film magnetic head has a relationship of Tp≦Ly wherein a gap film has a flying plane gap film exposed above a flying plane from a medium, and a back gap film provided behind the flying plane gap film; and a distance of the back gap film from the flying plane from the medium is approximately the same as the Tp.