Patent ID: 8498079
Filing Date: 2013-07-30
Classification: G11B

Abstract:
1. A perpendicular magnetic recording (PMR) writer, comprising: (a) a main pole layer comprised of a trailing side and a leading side with respect to a down-track direction, and two sides connecting said leading and trailing sides; the leading side has a leading edge at an air bearing surface (ABS) and the trailing side has a trailing edge at the ABS; (b) a gap layer adjacent to and surrounding the main pole at the ABS wherein the gap layer includes a write gap along the trailing side and trailing edge, a lead gap along the leading side and leading edge, and a side gap along each of the two sides of the main pole; (c) a leading shield and side shields adjoining the lead gap and each side gap, respectively, the leading shield and side shields are comprised of an anisotropic (−Ku) magnetic material with a hard axis in a direction perpendicular to the ABS, the leading shield has a first side along the ABS, and a second side formed parallel to the first side and formed a first distance from the ABS; and (d) a composite trailing shield including an isotropic magnetic layer with a moment of about 24 kG adjoining the write gap, and an anisotropic (−Ku) magnetic layer on an opposite side of the isotropic magnetic layer with respect to the write gap, the anisotropic (−Ku) magnetic layer has a first side along the ABS, a second side formed parallel to the ABS at a second distance from the ABS, and a third side adjoining the isotropic magnetic layer, the isotropic magnetic layer extends a distance greater than the second distance from the ABS.