US Patent 9899901 Coil and method of manufacturing coil

A flat coil includes at least first and second coil layers having the shape of a ring and stacked, each of the first and second coil layers includes a pair of linear portions facing each other in a first direction and a pair of end portions facing each other in a second direction crossing the first direction, and the flat coil is bent on at least one of the end portions. The flat coil is an α-winding coil and is bent toward the first coil layer from the second coil layer. A first end face of the first coil layer in the second direction and a second end face of the second coil layer in the second direction are positioned on the same plane at the end portion to be bent.