An electronic device includes a substrate, first signal lines, pixel structures, first pads, transmission pads, a first combination circuit board, and a transmission circuit board. The first pads are electrically connected to some of a plurality of first signal lines. The transmission pads are electrically connected to some of the first signal lines. The first combination circuit board is disposed between a first side and a second side of the substrate opposite to each other. The transmission circuit board is disposed between the first combination circuit board and the second side of the substrate. The first combination circuit board is electrically connected to at least some of the first pads, and a first pitch exists between the adjacent first pads. The transmission pads are electrically connected to the transmission circuit board, and a transmission-pad pitch exists between the adjacent transmission pads. The transmission-pad pitch is greater than the first pitch.