Merged magnetic head which includes a write head with single-sided notched first pole piece

Abstract

A single-sided, notched write head is provided for writing narrow erase band servo tracks as well as a double-notched write head, and for writing data tracks better than a double-notched write head. The single-sided, notched write head writes a narrow erase band on the notched side and a wide erase band on the unnotched side. In one embodiment, only one side of the first pole piece layer is notched, and in another embodiment a first side of the first pole piece layer is notched more than a second side. By writing servo tracks only a fraction of the track width of the write head, a wide erase band region is overwritten so that a narrow erase band is on each side of the servo track. Data tracks are written with a narrow erase band on one side and a wide erase band on the other side. The wide erase band on one side of the data track allows more flexibility in spacing the read head from adjacent tracks. The single-sided, notched write head can be manufactured with methods that require less processing time than a double-notched write head. In one method, a notching layer is employed where removal of a small corner of the notching layer provides the first pole piece with a notch. Other methods employ photoresist to protect the side of the first pole piece that is not to be notched, and/or oscillating the workpiece less than 360°. so that milling is more concentrated at the notch site.

Dependencies are inferred from the claim text.