The over-current protection device of the present invention can be used for over-current protection to PCM. The over-current protection device comprises a PTC device, at least one insulation layer; at least one electrode layer and at least one conductive channel. The insulation layer is placed on a surface of the PTC device, and the electrode layer is formed on the insulation layer afterwards. As a result, the insulation layer is between the electrode layer and the PTC device. The electrode layer serves as a surface of the over-current protection device. The conductive channel electrically connects the PTC device and the electrode layer. In an embodiment, the conductive channel is a blind hole penetrating through the electrode layer and the insulation layer and ending at the surface of the PTC device, and the surface of the blind hole is coated with a conductive layer to electrically connect the PTC device and the electrode layer.