Surface-mountable over-current protection device

A surface-mountable over-current protection device, comprising:

• a PTC material layer having opposite left and right ends, the left end comprising a left notch, the right end comprising a right notch;
• a first conductive layer comprising a primary portion disposed on an upper surface of the PTC material layer and a secondary portion extending over the left notch;
• a second conductive layer comprising a primary portion disposed on a lower surface of the PTC material layer and a secondary portion extending over the underside of the right notch;
• a left electrode electrically connecting to the first conductive layer;
• a right electrode electrically connecting to the second conductive layer;
• a left conductive member connecting to the left electrode and the first conductive layer and isolating from the second conductive layer;
• a right conductive member connecting to the right electrode and the second conductive layer and isolates from the first conductive layer;
• a left insulating member disposed in the left notch and between the left conductive member and the PTC material layer for isolation;
• and
• a right insulating member disposed in the right notch and between the right conductive member and the PTC material layer for isolation;
• wherein the PTC material layer is not in direct contact with the left and right conductive members, and the primary portion and the secondary portion of the first conductive layer or the second conductive layer have difference thicknesses.