Planar coil inductor with closed magnetic circuit.

Abstract

Disconnection in a conductor or magnetic core is a serious problem for fabrication of inductors. Planar coil inductor with closed magnetic circuit is proposed and the characteristics are discussed. A conductor of the planar coil inductor is patterned on a plane, in order to prevent the growth of disconnection on the conductor. For decreasing the magnetic resistance, cross sections of core junctions are regulated, which have a risk of disconnection. An inductor made for trial comprised one hundred magnetic cores whose size are 180μm×180μm. The dimensions of the inductor are 2.3 mm×2.3 mm. The inductance of 50 nH was realized, and the resonance frequency was about 400 MHz.