A display device includes: a flexible substrate having a display area for displaying an image and a peripheral area outside the display area; a first pad electrode in the peripheral area of the flexible substrate; and a driver connected to the first pad electrode. The driver includes: a circuit board including a driving circuit; a second pad electrode on one side of the circuit board and facing the first pad electrode; a convex structure on one side of the second pad electrode and having an oval cross-section; and a bump electrode on one side of the convex structure and connected to the first pad electrode. The bump electrode includes a column covering the convex structure and a convex portion extending from one side of the column and protruding to the first pad electrode.