Power supply arcing

The trend to pack more power in smaller spaces is leading to higher rates of computer power supply arcing in the field. Power density increase is being achieved by decreasing the spacing between features such as the power train MOSFET leads and by increasing the switching frequency. Both of these changes make power supplies more prone to field arcing. This paper discloses a technique called the partial vacuum test to predict the arcing propensity in power supplies. The partial vacuum test also helps determine the corrective actions needed to avoid field arcing by indicating the locations susceptible to arcing. The paper also describes a test called the zinc spray test that can help determine the minimum spacing between features, subjected to high voltages with high frequency harmonics, that will not arc in the field.