Wafer-level fabrication of high-power-density MEMS passives based on silicon molding technique

Conference: CIPS 2012 - 7th International Conference on Integrated Power Electronics Systems
03/06/2012 - 03/08/2012 at Nuremberg, Germany

Proceedings: CIPS 2012

Pages: 5Language: englishTyp: PDF

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Li, Jiping; Xie, Huikai (Department of Electrical and Computer Engineering, University of Florida, USA)
Ngo, Khai D. T.; Lu, Guo-Quan (Department of Electrical and Computer Engineering, Virginia Tech, USA)

This paper reports a novel MEMS fabrication technology that can integrate toroidal inductors or transformers into silicon substrate. Such toroidal windings are realized by electroplating copper to form 200micrometer-deep through-silicon vias (TSVs) and 60micrometer-thick copper lines on both sides of the silicon substrate. Meanwhile, the magnetic core is formed by filling deep silicon trenches with a composite of magnetic powders and a polymer. A 13 x 13 x 0.32 mm3 toroidal inductor with a measured inductance of 160 nH has been fabricated. The Q factor of this inductor is 10.5 at 14 MHz. Toroidal transformers with Polyimide as the dielectric material between stacked windings were also fabricated.