Hybrid Integration of Screen-Printed RFID Tags and Rigid Microchip on Paper

Hybrid or heterogeneous integration of silicon technologies and printed electronics is a promising approach for high-performance flexible electronics. It is essentially the integration of rigid microchips with the printed circuit on a flexible substrate. However, microchips with no-lead and millimeter-size pitch introduce practical challenges in terms of precise electrical bonding onto the printed pattern. The differences in mechanical and thermal requirements also make it challenging to use conventional bonding and interconnect technology to robustly connect the microchips on flexible substrates. The focus of this work is to present these challenges with respect to different substrate–adhesive combinations and to provide a facile technique for integrating near-field communication (NFC) microchips on different flexible substrates. Following the successful integration, the smart tags were characterized to demonstrate reliable performance in the NFC reading range. While presenting a hybrid integration for the smart tag, this work also shows a potential solution for several other applications of flexible electronics where high performance cannot be achieved by printed electronics alone.