Radial-leaded over-current protection device

摘要

A radial-leaded over-current protection device includes a PTC device, first and second electrode leads and an insulating encapsulation layer. The PTC device has first and a second conductive layers and a PTC material layer therebetween. The PTC material layer has a resistivity less than 0.18 Ω-cm and includes crystalline polymer and conductive ceramic filler. The ceramic filler has a resistivity less than 500 Ω-cm and is 35-65% by volume of the PTC material layer. The first electrode lead has an end connecting to the first conductive layer, whereas the second electrode lead has an end connecting to the second conductive layer. The insulating encapsulation layer wraps the PTC device and the ends of the conductive layers. The radial-leaded over-current protection device at 25° C. has a value of hold current thereof divided by an area of the PTC device ranging from 0.027-0.3A/mm2. Each electrode lead has a cross-sectional area of at least 0.16 mm2.

主权项

1. A radial-leaded over-current protection device, comprising:
a PTC device comprising a first conductive layer, a second conductive layer and a PTC material layer sandwiched between the first and second conductive layers, the PTC material layer having a resistivity less than 0.18 Ω-cm, and comprising crystalline polymer and conductive ceramic filler dispersed therein; the conductive ceramic filler has a resistivity less than 500μΩ-cm and comprises 35% to 65% by volume of the PTC material layer; a first electrode lead of which one end connects to the first conductive layer; a second electrode lead of which one end connects to the second conductive layer; and an insulating encapsulation layer wrapping the PTC device and the ends of the first and second electrode leads connecting to the PTC device; wherein the radial-leaded over-current protection device has a resistance less than 100 mΩ, and the radial-leaded over-current protection device, at 25° C., indicates that hold current thereof divided by an area of the PTC device is in the range of 0.027-0.3 A/mm2; wherein each of the first and second electrode leads has a cross-sectional area of at least 0.16 mm2 if the hold current of the radial-leaded over-current protection device at 25° C. is 0.05-2.4 A; each of the first and second electrode leads has a cross-sectional area of at least 0.5 mm2 if the hold current of the radial-leaded over-current protection device at 25° C. is 2.5-11.9 A; and each of the first and second electrode leads has a cross-sectional area of at least 0.8 mm2 if the hold current of the radial-leaded over-current protection device at 25° C. is 12-16 A.