Multilayer Inductors (MLI) are manufactured using semiconductor material typically based on ferrites with inorganic dopants (a black, nonconductive, brittle magnetic material).
MLI´s are inductors constructed by layering the coil between the layers of core material. When using tape cast ceramic layers, holes are punched and filled with the conductor used to make the interconnection between the spiral's circles screen printed in the subsequent layers. The coil normally consists of a bare metal material (no insulation). This technology is normally referred to as “non-wirewound”. Two technologies exist to manufacture these components: the so called wet technology using screen printing and the dry technology using tape casting. A comparison can be found in the paper by Oostra and Höppener in 2001.
The inductance value can be made larger by adding additional layers for a giving spiral pattern. These are all ploys to multiply the inductance of a given coil by the "permeability" of the core material. Packing methods for chip inductors include tape reel, tray, tube, or bulk pack. Common applications include common mode choke, general purpose, high current, high frequency, power inductor, and RF choke.