Microcracks of the alumina of the thin-film head: study and simulation

Author

Chekanov, A.S. ; Low, T.S. ; Alli, S. ; Liu, B. ; Teo, B.S. ; Hu, S.

Author_Institution

Magnetic Technol. Center, Nat. Univ. of Singapore, Singapore

Volume

31

Issue

6

fYear

1995

fDate

11/1/1995 12:00:00 AM

Firstpage

2991

Lastpage

2993

Abstract

A study of the microcracks found in the alumina of a magnetic thin film head is presented. A model of the alumina fatigue crack initiation and growth is proposed. Thermal expansion of the energized wires leads to high stress at the pole tip area. Crack initiation usually occurs at the outer edge of the alumina, due to the mechanical damage caused by the rotating disk surface. Further crack growth is caused by fatigue in the alumina. The crack is attracted to the pole tip area, affecting the magnetic head performance. Magnetic Force Microscopy is used to study the effects of the crack on the magnetic fringe field of the head

Keywords

alumina; fatigue cracks; hard discs; magnetic force microscopy; magnetic heads; magnetic recording; magnetic thin film devices; microcracks; thermal expansion; thermal stress cracking; Al₂O₃; energized wires; fatigue crack growth model; fatigue crack initiation; high stress; low flying height magnetic disk drive; magnetic force microscopy; magnetic fringe field; magnetic head performance; mechanical damage; microcracks; pole tip area; rotating disk surface; simulation; thermal expansion; thin-film head; Fatigue; Magnetic films; Magnetic force microscopy; Magnetic forces; Magnetic heads; Surface cracks; Thermal expansion; Thermal stresses; Transistors; Wires;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.490247

Filename

490247