Write induced track misregistration due to magnetic center shifts in thin film inductive heads

Author

Salo, Michael P. ; Tang, Yaw-Shing ; Gallagher, Timothy J.

Author_Institution

Storage Syst. Div., IBM Corp., San Jose, CA, USA

Volume

30

Issue

6

fYear

1994

fDate

11/1/1994 12:00:00 AM

Firstpage

3882

Lastpage

3884

Abstract

The effect of writing on track misregistration in thin film heads for hard disk drives is discussed. An experimental technique is presented which shows that writing causes changes in the magnetic state of the head. These magnetic changes are interpreted by the servo channel as shifts in the position of the head. Real track misregistration occurs as the servo tries to compensate. Typical variations in head position have a standard deviation of 2 to 4 microinches. From ontrack testing of a known unstable head it is concluded that unstable waveforms do not necessarily indicate a magnetic center shift. The opposite behavior has also been seen: magnetic center shifts occur with no noticeable change in waveform

Keywords

magnetic heads; magnetic thin film devices; position control; hard disk drives; head position variation; magnetic center shifts; servo channel; thin film inductive heads; write induced track misregistration; Hard disks; Magnetic domains; Magnetic films; Magnetic heads; Servomechanisms; Size control; Testing; Timing; Vibrations; Writing;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.333932

Filename

333932