Abstract: A printed board coil forms a coil with a plurality of turns, each formed by stacking a first layer having a first winding pattern and a second layer having a second winding pattern while having an insulation layer intervening therebetween. The first layers and the second layers are used for forming each of the coils. The coils are stacked having each of the insulation layers intervening between the coils by arranging the first layer and the second layer alternately in the stacking direction of the respective layers. The coils are connected in parallel to one another.

Abstract: Variation in inductance is reduced with a secondary-side coil substrate on which a plurality of wiring layers are superimposedly disposed, and a plurality of coils provided in the secondary-side coil substrate. On the wiring layer, coil patterns corresponding to parts of one circumferences of the coils are formed. On the wiring layer, coil patterns corresponding to remaining parts of the one circumferences of the coils are formed. The coil patterns, and the coil patterns that are provided on the different wiring layers are connected to each other via conduction points in a superimposition direction of the wiring layers, and the one circumferences of the respective coils are formed.