US Patent 10147540 Planar coil element and method for producing the same

In a planar coil element and a method for producing the same, a metal magnetic powder-containing resin containing an oblate or needle-like first metal magnetic powder contains a second metal magnetic powder having an average particle size (1 μm) smaller than that (32 μm) of the first metal magnetic powder, which significantly reduces the viscosity of the metal magnetic powder-containing resin. Therefore, the metal magnetic powder-containing resin is easy to handle when applied to enclose a coil unit, which makes it easy to produce the planar coil element.