PMR writer with patterned shields for adjacent track erasure improvement

摘要

A PMR writer is disclosed wherein one or more of the leading shield, side shields, and trailing shield are comprised of first portion that is elongated in a cross-track direction at the ABS, and a second portion consisting of a plurality of pads each having a side adjoining the first portion along a side opposite the ABS. Pads may have a polygonal shape or a shape with curvature and are separated by portions of a dielectric layer. When a length of the pads in a down-track direction is substantially greater than a width in a cross-track direction and height in a vertical direction, then shape anisotropy in the shield is biased in a down-track direction and is perpendicular to the driving flux direction from the main pole tip thereby minimizing 180 degree rotations in magnetization and associated adjacent track erasure.

主权项

1. A perpendicular magnetic recording (PMR) writer, comprising:
(a) a main pole layer comprised of a main pole tip with one end having a leading edge and trailing edge at an air bearing surface (ABS), a second end that adjoins a yoke portion at a neck height distance from the ABS, and two sides that are perpendicular to the ABS and formed between the first and second ends; (b) a gap layer adjacent to and surrounding the main pole tip wherein the gap layer includes a write gap along a trailing side and the trailing edge, a lead gap along a leading side and the leading edge, and a side gap along each of the two sides of the main pole tip; and (c) a fully all wrapped around (AWA) shield structure comprising a trailing shield formed on the write gap, a leading shield that adjoins the leading gap, and two side shields with one side shield on each side of the main pole tip and adjoining a side gap, and wherein at least the two side shields have a patterned structure comprising:
(1) an elongated portion made of a magnetic material and having a first length in a down-track direction, a first side at the ABS, a first end facing a side of the main pole tip, and a second side opposite and parallel to the first side, the first and second sides have a first width in a cross-track direction, the second side is a first distance (first height) from the ABS in a vertical direction that is perpendicular to the ABS; and(2) a plurality of patterned magnetic features adjoining the second side of the elongated portion, each of the patterned magnetic features is separated from an adjacent patterned magnetic feature by a space and has a second width in a cross-track direction, a second height in a vertical direction, and a second length in a down-track direction such that the second length is substantially greater than the second height and second width to generate a shape anisotropy bias in the down-track direction, or the second height is substantially greater than the second length and second width to generate a shape anisotropy bias in the vertical direction.