A base member includes a base through-hole which interconnects an upper opening and a lower opening. An insulating sheet portion is disposed at a lower surface side of the base member. The insulating sheet portion covers at least a portion of the lower opening. Lead wires extending from coils extend to the lower surface side of the base member through the base through-hole. The lead wires extend radially outward along a lower surface of the insulating sheet portion while making contact with the insulating sheet portion. The lead wires are soldered to land portions of a circuit substrate. The lower opening is covered with a sealing material. The circuit substrate includes a first region. The insulating sheet portion is defined by a smaller number of layers than the first region.