A chip-on-film device including a flexible circuit film having a wire, a passivation layer having a hole, an adhesive layer, a first pad, a second pad, an interconnection, and a bump is provided. A part of the adhesive layer is disposed in the hole. The first pad and the second pad are disposed under the passivation layer.A part of the interconnection is disposed under the passivation layer, and disposed between the first pad and the second pad. The bump is electrically connected to the first pad via the adhesive layer. The bump is welded on the wire. A part of a first part of the bump overlaps the first pad, a second part of the bump extends to an outside of the pad and at least partially overlaps the interconnection, and the third part of the bump overlaps the second pad.