A MEMS-based Double-layer Spiral Planar Inductor using Patterned Permalloy filled with Ferrite/Polyimide Composite Materials as Magnetic Layers

Abstract

Abstract.A MEMS-based planar inductor with double-layer spiral coil structure is developed in this study. The patterned permalloy which blank are filled with MnZn ferrite/PI composite materials is used as the magnetic layer of the inductor as well as the magnetic shielding layers. The double-layer planar inductor has a size of 1.5×1.5×0.15mm consisted of 13-turn spiral Cu coil for each layer and a 20-μm-thick patterned permalloy magnetic layers filled with MnZn ferrite/PI composite materials above and below. The inductor shows a higher inductance than the traditional planar inductor. The patterned permalloy made the inductor more stable in high frequency than the none-patterned. And the filling MnZn ferrite/PI composite materials made the inductor to achieve more excellent insulation and lower dissipation characteristics. And the inductor has an inductance of 1.3μH and quality factor of 2.8 at 1.5MHz.