A Soft Magnetic Moldable Composite With Tri-Modal Size Distribution for Power Electronics Applications

Soft magnetic moldable composites (SM
²
Cs) would be ideal for magnetic integration in power electronics converters because they can be readily processed at low temperature without pressure into the core shapes prescribed for the circuits. However, most of the existing SM
²
Cs have low relative magnetic permeability (<; 30) and low saturation flux density (<; 1 T). To improve the magnetic properties, we combined three different magnetic powders giving rise to a tri-modal size distribution and an acrylic polymer to produce a paste of tri-modal SM
²
C. The paste was molded and then cured below 200 °C without pressure to form cores offering a relative permeability over 30, a saturation flux density over 1.0 T, and a low core-loss density. The ease of its processing and high-performance properties make this SM
²
C a good candidate material for power electronics applications.