Patent ID: 7852192

Claim:
An over-current protection device, comprising: a positive temperature coefficient (PTC) device, comprising a PTC material layer and two metal electrode foils on an upper surface and a lower surface of the PTC material layer; at least one insulation layer placed on a surface of the PTC device; at least one electrode layer placed on a surface of the insulation layer, the insulation layer being between the electrode layer and the PTC device and serving as a surface of the over-current protection device; and at least one conductive channel electrically connecting the PTC device and the electrode layer and comprising: at least one blind hole penetrating through the electrode layer and the insulation layer and ending at a surface of the PTC device; and at least one conductive layer on a surface of the blind hole and being configured to electrically connect the PTC device and the electrode layer; wherein the PTC device, the insulation layer and the electrode layer form a stack structure.