An Exploration of Leakage Current

Leakage currents of commercial capacitors are notoriously difficult to analyze because they are the sum of several independent current flow mechanisms and because they are history dependent.

A test procedure has been established for investigation of background current in solid tantalum capacitors and to deduct it from the total current. The “excess current” can then be investigated in more detail so establishing its dependence on time, voltage, and temperature. This excess current is seldom related to total surface area of the dielectric and is most likely localized in discrete regions or flaws.