US Patent 8049588 Coil device

A coil device includes first and second coils and a package for sealing the first and second coil. The first coil has a first winding including a first conductor wire wound about a first winding axis, and first and second ends which are both ends of the first conductor wire. The second coil has a second winding including a second conductor wire wound about a second winding axis, and third and fourth ends which are both ends of the second conductor wire. The second winding axis is arranged with the first winding axis. The second end of the first coil is connected with the third end of the second coil. The first end of the first coil and the fourth end of the second coil are adapted to be connected to an outside of the package. This coil device reduces magnetic flux leakage to outside of the package.