PMR write head with modified main pole shape to minimize adjacent track interference

摘要

A magnetic writer has a magnetic pole with projections extending laterally and symmetrically from each side. The pole tip of the magnetic pole is positioned at the ABS of the writer where it is surrounded in a mirror-symmetric fashion by side shields that are co-planar with the ABS. The projections can be the ends of a rectangular bar of soft or hard magnetic material, different than the main pole material, passing completely through the main pole and parallel to the ABS or they can be part of the peripheral shape of the main pole without changes to its material structure. In either case, they impart a shape anisotropy to the main pole and dilute the otherwise concentrated magnetic flux emerging from the pole tip that cause flux leakage from the side shields and undesirable adjacent track interference.

主权项

1. A magnetic writer comprising:
A main pole tapering to a narrow pole tip at an air bearing surface (ABS); A pair of side shields, mirror-symmetrically disposed to either side of said pole tip, wherein each of said pair of side shields has a face that is coplanar with said ABS and surrounding said pole tip; wherein said side shields are separated from said pole tip by a gap; wherein a horizontal cross-section of said main pole has a peripheral shape that is symmetric about a centerline, triangular and tapering towards said ABS; wherein said periphery is interrupted by two projections that extend horizontally, co-linearly and symmetrically from said periphery; wherein said projections have an aspect ratio, R, which is the ratio of the horizontal length of said projection, divided by the height of said projection in a direction perpendicular to said ABS; wherein said horizontally co-linear projections are substantially parallel to said ABS and wherein said projections are positioned at a perpendicular distance, denoted d_ABS, from said ABS.