Journal article ยท Ahead of Print article
High-Q 3D Microfabricated Magnetic-core Toroidal Inductors for Power Supplies in Package
Department of Micro- and Nanotechnology, Technical University of Denmark1
Silicon Microtechnology, Department of Micro- and Nanotechnology, Technical University of Denmark2
Department of Electrical Engineering, Technical University of Denmark3
Electronics, Department of Electrical Engineering, Technical University of Denmark4
Tyndall National Institute5
DTU Danchip, Technical University of Denmark6
Integration of power inductors is a roadblock in realizing highly miniaturized power supply in package (PwrSiP) and power supply on chip (PwrSoC). Inductors in such power system are used for energy storage and filtering, but they dominate in size and loss. This paper presents a novel 3D through-silicon via (TSV) magnetic-core toroidal inductor for PwrSiP.
The magnetic-powder-based core is embedded into TSV air-core inductor using a casting method. The unique air-core inductor design with a hollow core and suspended windings enable a complete core filling with microscale magnetic powders. TSV magnetic-core inductors are fabricated in a compact size of 2.4 x 2.4 x 0.28 mm with the core content varying from 63 to 88 weight percent of soft ferrite NiZn powders.
Small-signal measurements show a three-fold higher inductance of 112 nH and a 30% higher quality factor of 14.3 at 12.5 MHz for TSV magnetic-core inductors compared to similar TSV air-core inductors. The results are verified by the modelled results. The total core loss is characterized by large-signal measurements.
A suitable inductor is implemented in a zero-voltage-switching 12-MHz buck converter. The converter achieves a peak efficiency of 72% and the output power of 2.4 W converting 12 to 5 VDC.
Language: | English |
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Publisher: | IEEE |
Year: | 2018 |
Pages: | 74-85 |
ISSN: | 08858993 and 19410107 |
Types: | Journal article and Ahead of Print article |
DOI: | 10.1109/TPEL.2018.2847439 |
ORCIDs: | Thanh Le, Hoa , Nour, Yasser , Knott, Arnold , Jensen, Flemming , Han, Anpan and Ouyang, Ziwei |
Inductors Magnetic cores NiZn Powders Q-factor Si Soft magnetic materials TSV air-core inductors TSV magnetic-core toroidal inductors Through-silicon vias Toroidal magnetic fields Windings casting casting method core content efficiency 71.6 percent elemental semiconductors energy storage ferrites frequency 12.5 MHz high-q three-dimensional microfabricated magnetic-core toroidal inductors hollow core inductors integrated circuit packaging magnetic cores magnetic materials magnetic particles magnetic permeability magnetic powder based core microfabrication microscale magnetic powders miniaturized power supply in package nickel alloys power 2.4 W power convertors power inductors power supply in package (PSiP) power systems quality factor silicon small-signal measurements soft ferrite powders suspended windings three-dimensional in-silicon through-silicon via magnetic-core toroidal inductor three-dimensional integrated circuits through-silicon via (TSV) total core loss unique air-core inductor design voltage 12 V to 5 V zero-voltage-switching mode zinc alloys