Technical Glossary Dielectric Breakdown strength

[Dielectric breakdown strength]

Dielectric breakdown is the name of the phenomenon occurring when the voltage applied to an insulator exceeds certain limits; the insulator breaks down electrically and insulating properties are lost so that voltage flows. The voltage at this point is called the dielectric breakdown voltage; the value given by dividing the dielectric breakdown voltage by the material thickness is called the dielectric breakdown strength. Units are indicated in kV/mm; this is a specific value for a substance, but the value can decrease when air bubbles are introduced in the material and when the material absorbs moisture. A substance with a large dielectric breakdown strength is preferred as an insulator.