A mounting method of an electronic device includes providing an electronic device which includes a semiconductor chip body including an upper surface, a lower surface opposite to the upper surface, and side surfaces connecting the upper surface and the lower surface, a plurality of bumps disposed on the lower surface, and an under-fill element disposed on at least one side surface. The method further includes mounting the electronic device on a printed circuit board including connecting pads formed thereon. The bumps of the semiconductor chip body are connected to the connecting pads. The method additionally includes heating the under-fill element to a predetermined temperature to form an under-fill layer between the lower surface of the semiconductor chip body and the printed circuit board.