An Advanced Magneto-Resistive Head with a Newly Developed Electroplated High-B s Write Pole

A Magneto-Resistive (MR) head with a newly developed electroplated high-B s CoNiFe write pole has been developed for use in Hard Disk Drives (HDDs). The electroplated film has the leading high saturation magnetization (B s ) of 2.1 T to provide a soft magnetic film suitable for the write element in MR heads. Introducing high-B s films for the write-pole improves overwrite performance in 2,950 Oe high-H c media by 17.7 dB. For the read element, a large exchange coupling NiMn film has been developed. This film provides an excellent biasing scheme for fabricating abutted junction structure and the overlay structure. Signal stability evaluated by maximum asymmetry change during repeated read/write operations is improved by optimizing the write-core design and the magnetostriction of the magnetic layers as well as by optimizing the biasing scheme. Altitude sensitivity, which is defined as the change in flying height when atmospheric pressure is reduced from 1.0 to 0.7 atm, is suppressed from 11 to 5 nm by modifying the ABS (AirBearing Surface) design to increase the negative pressure induced. Typical read/write characteristics of MR heads with high-B s write-pole designed for 2.6 Gb/in 2 areal-density recording are described. An output-signal voltage of 400 μV/μm with excellent signal stability has been obtained.