A Novel Integrated Power Inductor With Vertical Laminated Core for Improved L/R Ratios

Author

Xiangming Fang ; Rongxiang Wu ; Lulu Peng ; Sin, Johnny K. O.

Author_Institution

Dept. of Electron. & Comput. Eng., Hong Kong Univ. of Sci. & Technol., Hong Kong, China

Volume

35

Issue

12

fYear

2014

fDate

Dec. 2014

Firstpage

1287

Lastpage

1289

Abstract

In this letter, a novel integrated power inductor with a vertical laminated NiFe magnetic core for improved inductance to resistance ratio (L/R) ratios is proposed and demonstrated. Both the windings and magnetic core are accommodated within a groove at the backside of a silicon substrate and connected to the front-side IC through vias for compactness. NiFe is used to increase the inductance, and vertical lamination is used to suppress the eddy current in the magnetic core and assist hard axis alignment. A 1-mm2 embedded inductor with 131-nil inductance and 60-mΩ dc resistance working in megahertz range is fabricated. The L/R ratio is increased by seven times compared with integrated inductors with similar area, making it suitable for portable electronics power conversion system-on-chip applications.

Keywords

eddy currents; electric resistance; inductance; laminations; magnetic cores; power inductors; windings; IC; L-R ratio; eddy current suppress; hard axis alignment; inductance; inductance to resistance ratio; integrated power inductor; portable electronics power conversion; resistance 60 mohm; silicon substrate; system-on-chip applications; vertical laminated magnetic core; vertical lamination; windings; DC-DC power converters; Inductors; Lamination; Magnetic anisotropy; Magnetic cores; Toroidal magnetic fields; DC-DC power conversion; integrated inductors; lamination; magnetic anisotropy; magnetic anisotropy.; monolithic inductors;

fLanguage

English

Journal_Title

Electron Device Letters, IEEE

Publisher

ieee

ISSN

0741-3106

Type

jour

DOI

10.1109/LED.2014.2362749

Filename

6937117