An approach to improve the efficiency of flux concentrator materials 2

This study is a resumption of finding possibilities to improve flux concentrator material for high frequency applications. Beside many other parameters the heat conductivity is an important factor for these materials. Thus, this study was focused on increasing thermal conductivity by adding boron nitride particles to the compound material. A material combination from a previous study (based on polyimide matrix with ferromagnetic carbonyl iron particles) formed the basis of this study. The thermal conductivity, chemical resistance and electrical insulation can be improved by using ceramic components, like boron nitride. Different amounts on ceramic particles were added and the effect on thermal conductivity were qualitatively analyzed. The study was supported by numerical calculations by using finite elements method (FEM). For this purpose, a numerical model was created and validated. The authors can conclude that the use of additional boron nitride particles leads to a higher thermal conductivity of the flux concentrator material. The simulation by FEM presents the interaction between coil and flux concentrator with an adequate precision.