The invention provides a display device, which employs ultra-thin flexible substrate with WOA disposed on both sides of the flexible substrate, wherein the WOA on the front side is directly connected to the active area, and the WOA on the back side passes through the holes in the flexible substrate to extend to the front side to connect to the active area. As such, the circuit area utilization is improved so that the same size of substrate area can carry almost twice the circuit structure to reduce the border width of the non-active area to achieve borderless or ultra-narrow borders.