Experimental verification of the AC resistance effect in Insulated Metal Substrate based Power Converters

Insulated Metal Substrate (IMS) based power converters are an excellent solution for thermal dissipation of power converters, but they suffer for limited layer options generating parasitic elements specially in High Frequency. The paper analyses and proposes experimental verification of IMS AC resistance in High Frequency power converter applications. The developed test bench can generate high current high frequency electrical signals in order to excite the IMS board parasitic AC resistances. The experimental validation highlights the importance of PCB lay-out in high frequency IMS boards where big area current loops and low copper areas increase significantly the resistance of the board. The developed tests verify a significant AC resistance effect in IMS boards with a temperature increase 4 times bigger at 500 kHz switching frequency than the equivalent DC current.