Stacked Flexible Parylene-Based 3d Inductors With Ni80fe20 Core For Wireless Power Transmission System

This paper presents a new high quality factor parylene-based stacked 3D spiral inductor with Ni80Fe20 core for wireless power transmission system. To achieve multilayers, planarization of parylene by oxygen plasma etching was realized. Ni80Fe20 was added as the magnetic core to enhance the performance. The maximum quality factor of the designed circular double-layer inductor reached 99.3 at 60MHz, which is much higher than the square coils with the same area. The double-layer inductor shows a 408% increment of maximum quality factor compared with single-layer coil. Furthermore, inductors with magnet arrays exhibited better performance than those with one magnet. Forming the power transmission system with these 3D inductors, the minimum attenuation was -26dB at 118MHz.