Partial discharges phenomenon in high voltage power modules

Partial discharges measurements have been performed on 3.3 kV IGBT power modules. Results using both the normalized and a new proposed test are compared. The new test, allowing the detection of partial discharges in all the insulating materials, is detailed. Elementary defect patterns are used to distinguish the main cause (dies or insulating materials) of the observed partial discharges in IGBT modules. Index Terms--Partial discharges, power semiconductors switches, packaging.