Magnetic pole self-annealing with current injection in perpendicular magnetic recording (PMR)

摘要

A main pole structure is selectively annealed by attaching a lead to a back side thereof and electrically connecting a lead to a front end of a narrow pole tip portion such that when a first current passes between the leads there is resistive heating that raises the temperature in the narrow pole tip to 250° C. to 400° C. As a result, defects and stress level are reduced in the narrow pole tip portion without substantially increasing a temperature in adjacent regions including the read head. Annealing may be performed with a partially completed main pole structure or with a completely fabricated write head. Leads may be removed or left in place after annealing is finished. The extent of annealing may be determined by calculating a difference between resistance measurements taken before and after annealing.

主权项

1. A method for locally annealing a main pole structure in a write head, comprising:
(a) providing a main pole structure on a substrate wherein the main pole structure comprises a narrow pole tip portion with a front end that adjoins a plane formed proximate to an eventual air bearing surface (ABS) plane, and a yoke portion that adjoins the pole tip portion along a back end at a plane that is a neck height distance from the eventual ABS plane; (b) attaching a first lead to a back side of the yoke portion to form a first terminal, and electrically connecting a second lead to the front end of the narrow pole tip portion to form a second terminal; and (c) injecting a first current through the first lead that passes through the main pole structure including the narrow pole tip portion and exits through the second lead thereby causing resistive heating to locally anneal the narrow pole tip portion without substantially elevating a temperature in adjacent layers of the write head.