Motor coil substrate

A motor coil substrate, comprising:

• a flexible insulating substrate having a cylindrical shape;
• a plurality of wirings formed on a first surface of the flexible insulating substrate and a second surface of the flexible insulating substrate on an opposite side with respect to the first surface;
• and
• a plurality of via conductors comprising copper plating penetrating through the flexible insulating substrate such that the plurality of via conductors is connecting the wirings formed on the first surface and the wirings formed on the second surface,
• wherein the plurality of wirings and the plurality of via conductors form a plurality of coils formed in spiral shapes, the flexible insulating substrate is wound more than one turn in a circumferential direction of the cylindrical shape such that the first surface on an inner side of the cylindrical shape and the second surface on an outer side of the cylindrical shape oppose each other, and the plurality of wirings is formed such that each of the coils has a half-turn wiring formed on the first surface, a half-turn wiring formed on the second surface, and one of the via conductors connecting the half-turn wiring formed on the first surface and the half-turn wiring formed on the second surface, and that the half-turn wiring of one coil on the second surface and the half-turn wiring of another coil adjacent to the one coil on the first surface are positioned to partially overlap each other.