SBIR Phase II: Reactive Silver Inks for High Performance Printed Electronics

The broader impact/commercial potential of this Small Business Innovation Research Phase II project will be to greatly enhance the capabilities of printed electronics via high performance conductive materials. This will be accomplished by the development and commercialization of novel silver and copper ink chemistries that are used in a number of device applications ranging from display bezels and interconnects, to high performance OLED electrodes, to ink specifically developed for high speed printing and smart packaging applications. The commercial impact of such developments will be the significant adoption and use of printed electronics material palettes across multiple consumer electronic device platforms. This will ultimately lead to more efficient device manufacture with a simultaneous improvement in performance. The printed electronics market is rapidly growing with progress hinging on fundamental material improvements. The objectives of this Phase II research project are to demonstrate scalability of reactive silver ink chemistries, formulations for productization standards, and development of reactive copper ink chemistries. The reactive silver ink chemistry has begun to receive significant traction with customers. This program plans to achieve scalability of this high performance ink by novel purification of silver salts to achieve a high conductivity at large scales with industrially relevant processes. Next the inks will need to adhere to specific productization standards. This includes modifications of the chemistry for various printing processes ranging from low viscosity (10 cPs) up to high viscosities for high-volume printing techniques (1000 cPs and higher). Also, modifications to the chemistry for various testing criteria such as adhesion, abrasion, and environmental tests such as humidity and heat cycling will be made. Finally, reactive copper chemistries will be further developed. Copper inks that can be processed thermally in the ambient environment represent both a significant challenge as well as a vast opportunity in the printed electronics market. We have developed novel chemistries based on various low molecular weight reducing agents and short-chain surfactants that both reduce the copper quickly under thermal cycling while protecting the surface from oxidation.