Characteristics and analysis of a thin film inductor with closed magnetic circuit structure

Author

Yamaguchi, M. ; Arakawa, S. ; Ohzeki, H. ; Hayashi, Y. ; Arai, K.I.

Author_Institution

Res. Inst. of Electr. Commun., Tohoku Univ., Sendai, Japan

Volume

28

Issue

5

fYear

1992

fDate

9/1/1992 12:00:00 AM

Firstpage

3015

Lastpage

3017

Abstract

A spiral inductor with closed magnetic circuit was fabricated by an RF sputtering machine and photolithography techniques. The inductance was twice as large as that of a reference sandwiched inductor. The authors analyzed the frequency characteristics of the proposed inductor from three points of view: inner current distribution, flux distribution, and eddy current in the magnetic film. The calculated results agree with the measured ones. It is demonstrated that the current distribution inside the inductors is mostly limited to within the area of the conductor up to several hundred megahertz. The frequency characteristics are influenced by the eddy current loss in the Permalloy film and the stray capacitance between the inductor and the ground plane. The permeability of the Permalloy film is less than that of its as-deposited state, but the closed magnetic circuit structure helps to reduce the influence of the demagnetizing field

Keywords

Permalloy; current distribution; eddy currents; inductors; magnetic circuits; magnetic flux; magnetic thin film devices; Permalloy film; RF sputtering; closed magnetic circuit structure; demagnetizing field; eddy current; flux distribution; frequency characteristics; inner current distribution; magnetic film; permeability; photolithography; spiral inductor; stray capacitance; thin film inductor; Current distribution; Eddy currents; Lithography; Magnetic analysis; Magnetic circuits; Magnetic films; Radio frequency; Spirals; Sputtering; Thin film inductors;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.179702

Filename

179702