Impact of Elevated Voltage and Temperature on Molded Power Inductors in DC/DC converters

For DC/DC converter applications molded inductors enable smaller footprints and lower profile due to the properties of the magnetic material. This allow the inductors to be used in more harsh environments. The higher electrical and thermal stresses over time can lead to an increase in magnetic core loss due to the degradation of the insulation between magnetic particles.

Würth Elektronik defines this degradation as a percolation phenomenon. But what exactly is percolation and what are its repercussions? And more importantly, how does it affect the long-term performance of a DC/DC converter?