An electronic device includes a substrate, a side wiring, a protective film, and a first filler. The substrate has a first surface, a second surface, and a side surface connected between the first surface and the second surface. The side wiring is disposed on the substrate and extends from the first surface to the second surface through the side surface. The protective film is disposed on the side wiring. The side wiring is sandwiched between the substrate and the protective film. An edge of the protective film extends beyond a side wall of the side wiring, and the protective film, the side wall of the side wiring, and the substrate define a gap. The first filler is disposed on the protective film and in the gap, wherein the first filler includes a first material and a plurality of particles mixed within the first material.