US Patent 7504923 Inductor structure

An inductor structure disposed over a substrate and comprising a first spiral wire and a second spiral wire is provided. The first spiral wire has a first end and a second end. The first end rotates in a spiral way outward from an inner portion of the first spiral wire. The second spiral wire and the first spiral wire are intertwisted with each other and symmetrically disposed about a symmetry plane. The second spiral wire has a third end and a fourth end. The third end rotates in a spiral way outward from an inner portion of the second spiral wire and is connected to the first end of the first spiral wire, so as to form a coil layer having a plurality of coil turns.