LEAD FREE CERAMIC COMPOSITION FOR PTC THERMISTOR AND PTC CERAMIC THERMISTOR THEREBY

摘要

PURPOSE: A ceramic composition for a lead-free PTC thermistor, a PTC ceramics thermistor manufactured therefrom, and a manufacturing method thereof are provided to manufacture the PTC ceramics thermistor including a Curie temperature over 130 deg C without containing lead. CONSTITUTION: A ceramic composition for a lead-free PTC thermistor contains a ceramic material marked as BT-xNKN in which Na0.5K0.5NbO3(NKN) is formed as a solid solution of BaTiO_3(BT). The ceramic material additionally contains 0~0.05 mol% of dopant material with Nb2O_5 powder. The manufacturing method of the PTC ceramics thermistor comprises the following steps: preparing BaTiO_3 with the purity of 99.9%; manufacturing (1-x)BT-xNKN ceramic material powder; ball milling the ceramic material powder; crushing the ceramic material powder after drying and adding into mortar; incinerating the ceramic material powder; ball milling the ceramic material powder for 24 hours; and manufacturing the ceramic material powder into a sensor shape.