Impact of Conformal Coating Material on the Reliability of Thinner Wirewound CMC Inductors

This white paper addresses the effect of conformal coating material selection on the reliability of wirewound common mode choke (CMC) inductors, particularly those using thinner wire (≤0.08 mm). Thermal expansion properties of certain coatings introduce mechanical stress during thermal cycling, significantly increasing the risk of wire breakage. This paper presents experimental results, compares common coating materials, and offers actionable guidance to improve reliability.