Planar inductor

As the first step for developing magnetic I.C, planar inductors have been investigated. Planar inductor, which does not require conventional winding, consists of planar coil and two magnetic films which sandwich the coil. Design parameters have been obtained for four types of planar inductors, hoop type, spiral type, meander type and closed type. We fabricated a hoop type and a meander type planar inductor. The inductance of the hoop type was about 40 nH at 1 MHz, and showed flatness up to 10 MHz. In the meander type, the inductance was about 100 nH at 1 MHz, and showed a flat response till 40 MHz.