A fully integrated 3d tsv transformer for high-voltage signal transfer applications

A novel fully integrated 3D TSV (Through-Silicon-Via) transformer is demonstrated for high-voltage signal transfer. The transformer is embedded in a silicon substrate, with primary coil connecting to the front-side through TSV interconnects, and with secondary coil flip-chip connected onto another substrate. Using this approach, complete 3D integration can be achievedwith ultimate area efficiency and the smallest possible form factor compared with conventional on-silicon approaches. A coreless transformer is fabricated within a small chip area of 0.5 mm2. It achieves both high galvanic isolation of <4 kV DC and high voltage gain of >?3 dB from 10-100 MHz.