Heat-assisted wiring traces and a conductive support substrate are respectively formed on first and second surfaces of an insulating layer. Further, connection terminals electrically insulated from the support substrate and electrically respectively connected to the heat-assisted wiring traces are formed on the second surface of the insulating layer. Each connection terminal has an element connection portion, a pattern connection portion and a spread blocking portion. When a circuit element is connected to the element connection portion of the connection terminal by solder, spreading of a molten solder applied to the element connection portion to the pattern connection portion is blocked by the spread blocking portion.