A shield is provided, including a frame and a cover. The frame includes a plurality of frame side walls and a frame top structure. Each frame side wall includes at least one frame side wall wedge. The frame side walls are connected to the frame top structure, and the frame top structure includes at least one cantilever beam. The cover includes a plurality of cover side walls and a cover top structure. Each cover side wall includes at least one cover side wall opening. The frame side wall wedge is adapted to be wedged into the cover side wall opening to restrict the movement of the cover in a first direction. The cover side walls are connected to the cover top structure. The cover top structure includes at least one cover top opening. The cantilever beam is wedged into and abuts the cover top opening.