PURPOSE: A barrier is provided to obtain a simple structure of an insulating frame by forming a first upper side insulating beam and a second upper side insulating beam. CONSTITUTION: A first upper side insulating beam(21) is installed over the upper side and the lateral side of the substrate of an insulating frame. One end of an upper side terminal conductor(22) is installed to the center part of the first upper side insulating beam. A second upper side insulating beam(23) is installed on the insulating frame and a U-shaped opening end. The second upper side insulating beam is expanded from one end of the upper side terminal conductor. A middle part of the upper side terminal conductor is installed to the second upper side insulating beam.
