Fabrication of a Planar Inductor Using a Thick-Film Magnetic Metal Particle/Non-magnetic Material Composite for Micro Power Supply

In a previous study, a thick-film Mn-Zn ferrite particle/polyimide composite material for power inductors was developed using screen printing technique. This composite film enabled us to obtain a thin planar power inductor. However, downsizing of the planar inductor required that Mn-Zn ferrite particles be replaced by other magnetic particles with the higher permeability. In this study, we used two powdery magnetic metals to create a thick-film composite material, and fabricated downsized planar inductors using such composites. When used in a step-down chopper dc-dc converter, the fabricated inductors exhibited electric properties equal to those of competitive ready-made inductors, which are thicker than our planar inductor.