Impact of Grain Boundary Pinning Using Silicon Refractory Inclusions in Screen Printed Silver Flake Inks for High Temperature Printed Electronics Applications

The world of printed electronics is a fast-growing dynamic field employing the process of printing a functional material onto a low-cost substrate to form a device. Screen printing is one of the premier methods used to fabricate high-volume, low-cost devices typically with silver conductive pastes. These materials are limited to relatively low operational temperatures up to approximately 150 ⁰C ¹. In this work, we demonstrate the ability to improve the thermal stability of commercially available silver screen printable ink² to fabricate a temperature sensing printed device capable to operate at high temperatures up to 700 ⁰C. This is achieved by impregnating the silver ink with controlled quantities of silicon micro particles. First, we present the modification procedure of the ink and the mechanism employed to achieve enhanced thermal stability and its advantages compared to the traditional unadulterated silver ink ^3,4. Next, we outline the characterization procedure to quantify the grain growth and electrical conductivity of the modified ink processed at incremental temperature ranges over time. Further, we benchmark the enhanced stability of the modified ink versus the virgin ink and the state of the art⁵ illustrating how the modification potentially allows low-cost silver inks to be utilized in high temperature environments in aerospace, chemical production, automotive industries. Finally, we validate the performance of the modified ink under elevated temperature conditions as a all silver resistance temperature detector (RTD).<br/><br/>1. Kim, M. et al. Effect of Curing Temperature on Nano-Silver Paste Ink for Organic Thin-Film Transistors. j. nanosci. nanotech. 12, 3272–3275 (2012).<br/>2. Metalon HPS FG32 Technical Data Sheet.<br/>3. Akbarpour, M. R., Farvizi, M. & Kim, H. S. Microstructural and kinetic investigation on the suppression of grain growth in nanocrystalline copper by the dispersion of silicon carbide nanoparticles. Materials & Design 119, 311–318 (2017).<br/>4. Hu, J., Wang, X., Zhang, J., Luo, J. & Zhang, Z. A general mechanism of grain growth -I. Theory. Journal of Materiomics 1007–1013 (2021).<br/>5. Alan, S., Kim, S. B., Bailey, C., Ma, A. W. K. & Dardona, S. Direct Write Fabrication of Platinum-Based Thick-Film Resistive Temperature Detectors. IEEE Sensors Journal 18, (2018).