In one example, a board mating connection, which includes a ground unit in which a tapered portion is formed, includes: a signal contact unit which has one side in contact with a signal electrode of a board and is electrically connected to the signal electrode; a ground contact unit which has one side in contact with a ground electrode of the board and is electrically connected to the ground electrode; and a dielectric unit which is disposed between the signal contact unit and the ground contact unit, wherein the ground contact unit includes a first ground portion which has a first ground hollow portion and includes a second ground portion of which the other side is partially inserted into the first ground hollow portion and which has a second ground hollow portion, the first ground portion includes a first ground tapered portion formed on a wall thereof so as to have an inclined shape such that an inner diameter thereof is gradually decreased toward the other side thereof, and the second ground portion has the other end in contact with the first ground tapered portion and is relatively moved.