Thin film inductor

A thin film inductor, comprising:

• a first coil assembly including a first substrate and two first electrically conductive circuits respectively arranged on two surfaces of the first substrate that are opposite to each other, wherein each of the two first electrically conductive circuits has multiple turns of circuit;
• a first magnetic layer;
• a second magnetic layer;
• a second coil assembly including a second substrate and a second electrically conductive circuit, wherein the first magnetic layer is arranged between the second substrate and the first coil assembly, the second electrically conductive circuit and the first magnetic layer are respectively arranged on two sides of the second substrate that are opposite to each other, and the second electrically conductive circuit is electrically connected in series to one of the two first electrically conductive circuits;
• a second electrically conductive column;
• and
• a first dielectric layer covering the second electrically conductive column;
• wherein the first magnetic layer and the second magnetic layer are respectively arranged on the two surfaces of the first substrate that are opposite to each other, and the two first electrically conductive circuits are respectively embedded in the first magnetic layer and the second magnetic layer;
• wherein the first substrate has a first non-circuit layout, each of the two first electrically conductive circuits is arranged around the first non-circuit layout, and a ratio between an area of the first non-circuit layout and an area of the first substrate is between 0.1 and 0.3;
• wherein the second electrically conductive circuit is electrically connected to the one of the two first electrically conductive circuits through the second electrically conductive column, the second electrically conductive column passes through the second substrate and the first magnetic layer, and the second electrically conductive column is electrically insulated from the first magnetic layer through the first dielectric layer.