High Stability and Reliability Additively Manufactured Metal-Insulator-Metal Capacitors for High Temperature Applications

Throughout the last few years, there has been a significant increase in demand for high temperature capacitors due to the rising need for electronics in harsh environments, including aerospace, automotive, and oil and gas industries. With the continued growth of electronics in these environments, there is a need for the development of new materials and manufacturing techniques to drive advances in high temperature capacitor technology. Additive manufacturing is one promising approach for producing electronics that can withstand high temperatures, leading to improved performance and reliability in a wide range of applications. The present work describes the fabrication and testing of MIM (metal-insulator-metal) capacitors at high temperatures using gold as the conductor material. The substrates used in this work is 3D printed Lithoz 350D 99.8% alumina. The work details the fabrication process and evaluates the relative permittivity of high-temperature dielectric material. The adhesion strength at the interfaces is examined before and after aging for up to 250hours at temperatures as high as 750°C. The leakage current is measured for 100hours at varying temperatures and the insulation resistance is calculated. Furthermore, the capacitance is monitored during aging at temperatures up to 700°C and frequencies as high as 1MHz. Finally, the capacitance is measured at room temperature before and after subjecting the capacitors to 100 cycles of thermal cycling at three different temperature ranges. The adhesion between all interfaces of the MIM capacitors is found to remain high even after aging at 700°C, leakage currents are minimal and stable, and the capacitance remained very stable during and after aging and after thermal cycling.