A Polymer-Bonded Magnetic Core for High-Frequency Converters

Abstract

This paper presents a polymer-bonded magnetic core (PBMC) for high-frequency converters. The material of the magnetic core is composed of polymer matrices and special magnetic powder. With these materials, lightweight, nonbrittle, low-cost magnetic cores can be produced with flexible shapes and different dimensions. The magnetic field of an EI-type PBMC used for fly-back converter is obtained using two dimensional (2-D) finite element analysis (FEA). The detailed energy conversion process is studied with 2-D, direct-coupled field-circuit, and time-stepping FEA. The electromagnetic power conversion of the converter is illustrated with circuit and field analysis result. A 100 W fly-back converter is implemented with a novel-developed PBMC. The analysis is verified by experimental results, and the application feasibility is validated with the PBMCs for power conversion.

Polymer Magnetic Composite Core Based Microcoils and Microtransformers for Very High Frequency Power Applications

“…Through careful adjustment of the magnetic permeability on the one hand, and the particle size and shape on the other hand, one can tailor the magnetic response of the core to a specific need. Being a promising technique, it still has various disadvantages for example it is difficult to integrate it into a complementary metal-oxide-semiconductor (CMOS) process since most of the reported fabrication methods involve high temperature sintering and annealing of the magnetic cores [ 12 ].…”

Nanocrystalline Powder Cores for High-Power High-Frequency Applications

“…Generally, air gaps need to be added in ferrite core based inductors to reduce the effective permeability of the core and then to reduce the flux density [13], which will induce additional power loss due to fringing flux around air gaps and the complexity of the inductor structure and design [14]. In order to achieve adjustable permeability, higher saturation flux density and lower core loss at the high operating frequencies, the soft magnetic composites (SMCs), also known as soft magnetic powder cores, have become increasingly popular based on well-developed powder metallurgy [15]. The distributed micro air gaps formed by the binding materials (a minimum amount around 2-5 weight %) are adopted to reduce the permeability of powder cores.…”