Ultralow-profile micromachined power inductors with highly laminated Ni/Fe cores: application to low-megahertz DC-DC converters

Author

Park, Jin-Woo ; Allen, Mark G.

Author_Institution

Sch. of Electr. & Comput. Eng., Georgia Inst. of Technol., Atlanta, GA, USA

Volume

39

Issue

5

fYear

2003

Firstpage

3184

Lastpage

3186

Abstract

Micromachined inductors with submillimeter profiles and comparable electrical performance to thicker, commercially-available surface-mount devices, have been fabricated and characterized for low-megahertz dc-dc converters. The fabrication approach involves micron-scale lamination of Ni/Fe cores, combined with three-dimensional micromachined copper windings. The magnetic core of the fabricated inductor has 72 laminations of 1-μm-thick Ni/Fe films. The inductor dimension is 11.5 × 5.7 × 0.7 mm, and the dc resistance is 150 mΩ. A maximum Q of 9.2 at 3 MHz with an inductance value of 2.3 μH and a dc saturation current (I80) of 0.2 A were obtained. Use of this inductor in a regulated dc-dc boost converter circuit (7-12 V) operating at 2.2 MHz yielded 1.9-W power output at 71% efficiency.

Keywords

DC-DC power convertors; copper; eddy currents; ferromagnetic materials; iron; laminates; magnetic cores; magnetic thin films; micromachining; nickel; power inductors; 0.2 A; 0.7 mm; 1 micron; 1.9 W; 11.5 mm; 150 mohm; 2.2 MHz; 3 MHz; 5.7 mm; 7 to 12 V; 71 percent; Cu; Ni-Fe; de saturation current; electrical performance; highly laminated Ni/Fe cores; inductor dimension; low-megahertz DC-DC converters; magnetic core; micron-scale lamination; submillimeter profiles; surface-mount devices; three-dimensional micromachined Cu windings; ultralow-profile micromachined power inductors; Circuits; Copper; DC-DC power converters; Fabrication; Inductance; Inductors; Iron; Lamination; Magnetic cores; Magnetic films;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/TMAG.2003.816051

Filename

1233339