Printed electronics for extreme high temperature environments
Mohammed Alhendi, Firas Alshatnawi, El Mehdi Abbara, Rajesh Sharma Sivasubramony, Gurvinder Singh Khinda, Ashraf Umar, Peter Børgesen, Mark D. Poliks, David Shaddock, Cathleen Hoel, Nancy Stoffel, Tommyhing-K.H. Lam
Abstract
There is a rapidly growing interest in the development of electronic microsystems that can maintain functionality in high temperature environments, particularly in power generation and aircraft engines where the operating temperatures can exceed 500 °C. The current work presents a major advancement toward development of additively printed electronics made for high temperature applications. Here, the electronic system is represented by gold-based electrical structures that have been printed on 3D printed ceramic substrates. The substrate is alumina-based with a purity level of 99.8% and was fabricated through photopolymerization digital light processing (DLP). An aerosol jet printing technique that can deposit an ink stream down to 10 µm was utilized to fabricate gold-based electronic structures. The gold ink printability and its adhesion to the ceramic substrate were assessed. Furthermore, the microwave dielectric constant and loss tangent of the alumina substrate were extracted through measurements of the scattering parameters of transmission lines up to 750 °C. A 3D printed conformal broadband antenna was successfully fabricated and tested at temperatures up to 850 °C. The printed gold structures showed excellent stability and adhesion after aging at temperatures up to 750 °C. The substrate dielectric constant slightly increased for temperatures up to 450 °C and significantly increased for temperatures between 450 °C and 750 °C. It was found that the dielectric loss increased as the temperature increased. This work presents an entirely additive manufacturing-based approach to fabricate electronic components including substrates, interconnects, and RF elements for high temperature applications.