SBIR Phase I: Direct Write Printing of Metals by In-Situ Plasma Jetting for Flexible Hybrid Electronics

This Small Business Innovation Research Phase I project is focussed on developing a plasma jet printing technology to serve the printed electronics industry. Printed electronic devices including flexible electronics and flexible hybrid electronics (FHE) are next generation smart devices that have applications in both consumer and industrial segments. These devices combine the flexibility and low cost of printed substrates made of plastic with the performance of semiconductor devices to create a new category of electronics. The main challenge in FHE is integration of semiconductor die to the flexible substrate and interconnects. Plasma jet printing has high potential to address the problems associated with printed electronics manufacturing, in particular the interconnects. The plasma process control allows printing metallic materials with required electronic properties by in-situ treatment, thereby eliminating the need for post processing. The global market for printed electronics equipment is $1.5 billion in 2017 and is estimated to reach $4 billion globally in 2020 and growing at a compound annual growth rate of 38%. Immediate industrial application of our technology is in replacing wire bonding with direct write printing of metallic interconnects for flexible hybrid electronics. The intellectual merit of this project is in developing a plasma jet print head hardware for direct write printing of conducting metallic interconnects with reduced process steps. The project focus will be on technological de-risking of the print head hardware and process de-risking for reliable and re-producible printing. Developing the plasma process that can be used for pre-treatment of substrate, in-situ treatment of nanoparticles, printing and post processing all in one tool and simultaneously can reduce the process steps, number of equipments needed and time taken for manufacturing. Oxidation of metal nanoparticle ink and its limited shelf life is currently being addressed by polymer capping of the nanoparticles and thermal/laser processing. Developing a plasma process that can be used to print high quality conducting patterns using in-situ treatment can take the technology closer to adoption by printed electronics industry. The anticipated outcome of this project is a robust plasma jet print head and a process that can reliably and reproducibly print conducting metal films with tailored oxidation state and electronic structure. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.