Capacitive coupling of data and power for 3D silicon-on-insulator VLSI

We designed a 3D integrated multi-chip module that uses non-galvanic capacitive coupling to provide bi-directional communication and exchange power supply between two separate dies. A prototype was fabricated on a conventional 0.5 μm silicon-on-sapphire (SOS) process. We demonstrated that bidirectional communication can be achieved between the two dies at 1 Hz-15 MHz (100 MHz from simulations) while at the same time also transferring power to the receiver die. The non-galvanically connected prototype is an enabling technology for the simplification of 3D VLSI fabrication, wafer stacking and packaging.