| Ultra-low-cost printed electronics seek to reduce the manufacturing cost of electronics with less expensive, all-additive printing methods that conventional silicon manufacturing cannot replicate. But, in order to print these electronics, there is a trade-off in performance. Despite this, there are several applications for low-cost printed electronics including radio frequency identification (RFID) tags, electronic sensors, displays, smart cards, packaging, and printed circuit boards (PCB). In this work, inkjet and gravure printing are used to fabricate electronic devices. Particular emphasis is placed on inkjet printing. Based on performance requirements for the above applications, suitable electronic materials for printing are examined, including a soluble gold nanoparticle ink for metallization, printable organic dielectrics including polyimide and PVP, and a high performance pentacene precursor semiconductor ink. All of these materials have plastic substrate compatible activation temperatures (<200°C). Due to the "donut effect", and other complex inkjet phenomena such as differential wetting, each ink must be optimized to allow printing of smooth, well-defined structures and lines. The processing techniques developed for each ink are presented. Using these techniques, printed high-Q passive components and transistors were fabricated on plastic. The resulting devices represent some of the highest performance printed devices published to date and both their AC and DC properties are studied in-depth. Finally, based on the fabricated transistors, a manufacturing route to achieve the necessary performance, ft > 500 kHz, for the discussed applications is proposed. |
