US Patent 7364438 Electrical connection box

A case that houses a circuit component includes a frame along a peripheral edge of a circuit board, and a cover assembled to the frame so as to cover the circuit board, and connectors, facing an outer peripheral side of the frame are provided in the frame. In corresponding surfaces of the cover and each of the connectors, a first rib, a second rib, a first rib receiving groove, and a second rib receiving groove are formed that can regulate passage of a liquid in clearances between the connectors and the cover by fitting of protrusions and recesses. This prevents or limits a liquid outside the frame from entering the frame through the clearances between the connectors and the cover.