Protection device and circuit protection apparatus containing the same

A circuit protection apparatus, comprising:

• a protection device, comprising:
• a substrate having a surface provide with a first electrode and a second electrode;
• a fusible element comprising a first metal layer and a second metal layer, the second metal layer being disposed on the first metal layer, the second metal layer having a melting temperature higher than that of the first metal layer the first metal layer being an inner layer of the fusible element, the second metal layer being an outer layer of the fusible element;
• and
• a heating element;
• and
• a detector that senses a voltage drop or a temperature of a circuit to be protected;
• and
• a switch coupled to the detector to receive signals of the detector;
• wherein the second metal layer of the fusible element connects to the first electrode and the second electrode through solder, and the solder has a melting temperature lower than that of the first metal layer;
• wherein the switch turns on to allow current to flow through the heating element by which the heating element heats up to blow the fusible element when the detector senses the voltage drop or the temperature exceeding a threshold value.