SBIR-STTR Award

The broader impact/commercial potential of this Small Business Innovation Research (SBIR) Phase I project is to introduce and establish the foundations of a new class of electronic products - ultra-thin electronic devices embedded in thin, flexible, inexpensive, and environmentally friendly substrates such as common paper. The ultra-thin embedded electronics offer superior cost, flexibility, reliability, and security characteristics relative to conventional flexible electronics. The most significant applicable market for such products in the near term is that for Radio-Frequency Identification (RFID)-based devices. In 2014, shipments of passive RFID tags will approach 7 billion having a value of about $3.5 billion and an annual growth rate of about 25%. However, the application of the ultra-thin embedded electronics technology extends well beyond RFID. It encompasses both defense and commercial applications within the general category of flexible hybrid electronics. Examples of defense applications include wearable health monitors, disposable sensors, embedded sensors with communication capability for monitoring equipment and structural health, etc. Examples of commercial applications are counterfeit-proof 'smart' security, legal, and financial documents, wearable and disposable electronics, interactive media, and intelligent product packaging.

This Small Business Innovation Research (SBIR) Phase I project aims to study the feasibility of embedding ultra-thin electronic devices in thin flexible materials such as paper. Paper has been considered extensively as a substrate material for printed electronics. However, embedding ultra-thin, silicon-based flexible electronic devices inside paper during the paper making process has not been researched. Similarly, an extensive body of knowledge exists on the topic of device reliability. However, current research is almost entirely focused on the interconnection system between the chip and circuit board and on the situations where the entire device is subjected to cyclic thermal and/or mechanical stresses. Embedding hybrid electronic devices in thin flexible materials requires the semiconductor chips to be extremely thin, less than 50 microns and preferably about 20-25 microns thick. This is significantly thinner than the conventional chips. Still, no research has exclusively considered the survivability of such chips and the entire embedded electronic device under the stress and strain conditions typical for the paper making process. The results from this study will pave the path to developing ultra-thin electronic devices embedded in other thin flexible materials such as polymers, composites, and synthetic paper.

The broader impact/commercial potential of this Small Business Innovation Research (SBIR) Phase II project is to address one of the primary barriers to the emergence of flexible electronics -the inability to assembly and interconnect thinned integrated circuits (ICs) onto flexible substrates in a reliable, cost-effective, high volume manner. Flexible electronics has been the subject of many industry journals, trade shows, technical conferences and market research reports. All describe a new age of ubiquitous electronics with devices embedded in the structures and items around us. Flexible electronic devices, unlike today's devices that are rigid and boxy, can conform to natural, curved shapes that exist in the real world. However, flexible electronics have yet to have their predicted economic and social impact. A major reason is because the electronics industry has not yet found a reliable, low-cost method for assembling thin, flexible ICs onto flexible circuit boards. Today's 'pick-and-place' assembly technology cannot handle ICs thin enough to be flexible. Until a new method is developed and adopted, the potential of flexible electronics will likely not be realized.This Small Business Innovation Research (SBIR) Phase II project will advance the integrated circuit (IC) aspects of a flexible hybrid electronics technology to a level at which these devices can be produced reliably and in volumes in a production-relevant environment. While most of the components of flexible hybrid electronics technology relating to printed electronics methods have been adequately researched and developed, little has been done on the integration of solid-state semiconductor devices onto highly flexible, organic substrates. Partial results have been reported in the literature, however, no attempt has been made to provide a comprehensive, wafer-to-end product approach suitable for commercial applications. This project will address this gap by focusing on all the steps for IC integration, including the preparation for assembly of ultra-thin, flexible semiconductor dies, their attachment onto a flexible circuit board using laser-enabled assembly technology, and their reliable electrical interconnection. The anticipated end results will be a complete flexible hybrid electronics integration technology developed to a level of pilot production readiness.