Title :
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
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;
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2014.2362749
