Design, Manufacturing, and Characterization of Integrated Inductors With Two Magnetic Layers

Abstract

In this article, the simulation results, the technological steps of manufacturing, and the characterization results at low and medium frequencies (20 MHz to a few hundred MHz) of integrated inductors with two magnetic layers are presented. Simulation realized with the high-frequency structure simulator (HFSS) software allows the impact of the vertical and horizontal air gaps on the inductance value for inductors with two magnetic layers to be determined. Inductors with two magnetic layers are manufactured with magnetic thicknesses varying from 100 to 500μm. The interest of this new manufacturing process is compatible with most ferrite. The measurement results show good agreement with the simulation results. By minimizing the vertical air gap, the inductance value increases with a ratio equal to the relative permeability of the magnetic material when field lines are totally canalized into the magnetic layers. The extracted resistance evolution of the inductor on the frequency is explained by taking into account the skin and proximity effects for the conductor losses and the iron losses for the magnetic material.