Ultra-thin chip embedding and interconnect technology for system-in-foil applications

Flexible electronics are envisioned to be the major enabler for next generation consumer electronics where compactness, high mechanical stability, and bendability are the key factors. Among various technologies pursued in this emerging field, System-in-Foil (SiF) technology aims at building a system by simply integrating various flexible components inside polymeric foil. In this regard, commonly pursued technologies that are promoted as the low-cost alternative to conventional silicon technology are the large-area organic and printed electronics. The prime vision of these technologies is to fabricate low-cost electronic circuitry by simply printing with an ink-jet printer on a flexible foil. However, building high-performance electronic systems solely by these technologies are not feasible due to their inferior performance compared to the established silicon technology. Therefore, one approach to manufacture high-performance flexible systems is by encompassing the complementary merit of the organic, printed electronics and ultra-thin chips into one single system. The primary emphasis of this work is the development and characterization of the novel ChipFilmT-Patch technology intended for embedding and interconnecting ultra-thin chips (thickness ≤20 µm) inside composite polymer foil. One central aim of the technology in this regard is to make the complete fabrication process fully compatible with conventional CMOS processing. This allows the technology to be processed in mainstream semiconductor fabrication plants with ease. Moreover, use of conventional photolithography and metallization processes facilitates the fine-pitch chip to foil interconnectivity.