Analysis of eddy currents and thermal modeling of planar magnetic components with metal housing

In recent years, temperature rise due to high-frequency losses in magnetic components has become an important issue in power converters. One solution to this problem is to use a thin meander winding structure to increase the cooling area with the metal housing. However, the eddy current losses due to leakage flux from the magnetic core installed in the metal housing and the estimation of the maximum operating temperature of the core are not well discussed in the related literature. In this paper, the distribution of eddy currents due to leakage flux is analyzed by focusing on the relative permeability of the core and the thermal interface material between the core and the metal housing. The temperature characteristics were also experimentally confirmed. As a result, a trade-off between eddy current loss in the metal housing and core temperature was confirmed for the thickness of the thermal interface material. These insights offer valuable considerations for installation and operational reliability in the development of next-generation planar magnetic components.