The classic capacitor failure mechanism is dielectric breakdown. The dielectric in the capacitor is subjected to the full potential to which the device is charged and, due to small capacitor physical sizes, high electrical stresses are common. Dielectric breakdowns may develop after many hours of satisfactory operation. Open capacitors usually occur as a result of overstress in an application. For instance, operation of DC rated capacitors at high AC current levels can cause a localized heating at the. The following list is a summary of the most common environmentally "critical factors" with respect to capacitors. The design engineer must take into consideration his own applications and the effects caused by combinations of various. Differential capacitance in,, and is a measure of the voltage-dependent of a , such as an or a. It is defined as the derivative of charge with respect to potential.
