In respect to an electrical connection between a control circuit board 20 and bus bars 14 interbonded together, it is an object to enhance stability in quality and reliability in connection. As a solution for achieving the object, the control circuit board 20 is provided with a conductor segment 26 to be electrically connected to a specific one of the bus bars 14 on the opposite side of a rear surface thereof bonded to the bus bars 14, and a through-hole 24 penetrating a main body thereof at a position adjacent to the conductor segment 26 so as to expose the specific bus bar 14 therethrough. Further, an electrically-connecting member 70 is disposed to bridge over the through-hole 24 and the conductor segment 26, and soldered onto the conductor segment 26 and the bus bar portion located in the through-hole 24.