I read an application-note that says the heat-sink (when not electrically isolated), is one of major source of EMI. Well I think this can be corrected at some point by good EMI filters and a good case to prevent EMI/RFI.
But what about stray inductance and capacitance?
This presuming that:
- IGBTs, with the case electrically common to the collector.
- Individual heat sink for each IGBT.
Although EMI is a concern, as my question states, my concern too is to add stray inductance / capacitance to the circuit, increase the miller effect (even thought the IGBTs are being driven with negative gate bias, etc).
It does not need to meet Class A emissions, so at some point the EMI can be reduced to acceptable levels with good case and line filtering.