Mohammed A. Alam1, Michael H. Azarian1, Michael Osterman1, and Michael Pecht1
1CALCE, Center for Advanced Life Cycle Engineering, Department of Mechanical Engineering, University of Maryland, College Park, Maryland 20740, USA
The electrical conduction mechanism in an embedded capacitor with epoxy-BaTiO3 composite dielectric
and Cu electrodes is investigated in this paper. Leakage current was measured across the dielectric by
performing a voltage sweep from 0 to 100 V. The voltage sweep was performed at temperatures ranging
from 25°C to 125°C. Various electrical conduction models such as Schottky, Poole–Frenkel, and ionic
hopping were evaluated by comparing the functional dependence of leakage current on temperature
and voltage for each mechanism which was considered. It was observed that the conduction mechanism
was most consistent with Schottky emission. The contact potential barrier corresponding to Schottky
emission was found to be 1.29 eV.
The effect of combined temperature and voltage aging on the conduction mechanism was investigated by aging the embedded capacitor dielectric at 125°C and 100 V for 1680 h. To investigate the difference between combined temperature and voltage aging and temperature aging alone, some capacitors were aged only by temperature at 125°C for 1680 h. Measurements of leakage current as a function of temperature and voltage were performed at frequent intervals during the aging. It was observed that the value of leakage current did not increase during temperature and voltage aging unlike pure BaTiO3 dielectrics.