Planar-type inductor and fabrication method thereof

Abstract

A planar-type inductor that can restrain the maximum operable frequency from lowering even if the inductance part of the inductor is miniaturized. This inductor includes an insulating substructure and a patterned conductor layer having a predesigned geometric shape and formed on a chief surface of the substructure. The patterned conductor layer contains an inductance part for providing a wanted inductance value and a first lead part and a second lead part for electrically connecting the inductance part to an external circuit located outside the inductor. The inductance part has a first region and a second region located adjacent to each other at an interval. The inductor further includes a recess formed in the substructure between the first region and the second region of the inductance part. The recess extends along the first region and the second region. A parasitic capacitance between the first region and the second region is reduced due to the existence of the recess. Another patterned conductor layer extending along the pattern of the inductance part of the may be formed, instead of the recess, which reduces the parasitic capacitance due to the electrostatic shielding phenomenon.