Planar inductor with ferrite layers for DC-DC converter

Author

Fukuda, Yasutaka ; Inoue, Tetsuo ; Mizoguchi, Tetsuhiko ; Yatabe, Shigeru ; Tachi, Yoshihito

Author_Institution

Kawasaki Steel Corp. Tech. Res. Labs., Chiba, Japan

Volume

39

Issue

4

fYear

2003

fDate

7/1/2003 12:00:00 AM

Firstpage

2057

Lastpage

2061

Abstract

We fabricated planar inductors with ferrite layers by a screen printing, photolithography, and electroplating process. The screen printing method made it possible to obtain a coil spacing filled with ferrite. In this structure, the perpendicular leakage magnetic flux preferentially passes through the coil spacing and bypasses the copper conductor line, a path that is expected to reduce eddy current loss. Trial samples of a planar inductor with ferrite layers achieved a high-quality Q factor of 40-70 at 5 MHz. Magnetic field analysis revealed that the eddy current loss of the conductor line was only 2.4% of total loss.

Keywords

DC-DC power convertors; Q-factor; copper; eddy current losses; electroplating; ferrite devices; magnetic flux; photolithography; power integrated circuits; printing; thin film inductors; 5 MHz; Cu; NiZn; eddy current loss reduction; electroplating process; ferrite layers; high-quality factor; perpendicular leakage magnetic flux; photolithography; planar inductors; screen printing; Coils; Conductors; Copper; DC-DC power converters; Eddy currents; Ferrites; Inductors; Lithography; Magnetic flux; Printing;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/TMAG.2003.812708

Filename

1211182