IPC TM-650 2.5.7D

Abstract

The dielectric withstanding voltage test (also called high-potential, over potential, voltage breakdown, or dielectric strength test) consists of the application of a voltage higher than rated voltage for a specific time between mutually isolated portions of a PCB or between isolated portions and ground. This is used to prove that the PCB can operate safely at its rated voltage and withstand momentary over potentials due to switching, surges, and other similar phenomena. Although this test is often called a voltage breakdown or dielectric strength test, it is not intended that this test cause insulation breakdown or that it be used for detecting corona, rather it serves to determine whether insulating materials and/or conductor spacings are adequate.