Jose A. Romero, Michael H. Azarian, and Michael Pecht
CALCE, Center for Advanced Life Cycle Engineering, Department of Mechanical Engineering, University of Maryland, College Park, Maryland 20740, USA
Tantalum electrolytic capacitors have been on the market for more than half a century, in a range of applications. However, the most common design uses MnO2 as the electrolyte, which can be thermodynamically unstable and, upon failure, can damage the circuit. To mitigate this risk, an alternative to the MnO2 electrolyte was developed using conductive polymers. Compared to MnO2, polymer Ta capacitors are more resilient to surge current, have a lower equivalent series resistance, and are ignition-free. However, polymer electrolytes are susceptible to degradation at high temperature and humidity. This paper presents an experimental study of polymer Ta capacitors from two diﬀerent manufacturers, tested under six diﬀerent environmental conditions, and characterized electrically at intervals during those tests. A time-to-failure model was developed to predict the degradation as a function of temperature and humidity.