A polymeric positive temperature coefficient (PPTC) device including a PPTC body, a first electrode disposed on a first side of the PPTC body, and a second electrode disposed on a second side of the PPTC body, wherein the PPTC body is formed of a PPTC material that includes a maximum of 65% by volume of a conductive filler, wherein 10%-39% by volume of the PPTC material is a conductive ceramic filler and wherein the rest of the conductive filler includes at least one of carbon and a metallic filler.

A temperature sensing tape including a flexible, electrically insulating substrate, a plurality of temperature sensing elements disposed on the substrate, each temperature sensing element including a first electrode and a second electrode arranged in a confronting, spaced-apart relationship to define a gap therebetween, and a variable resistance material disposed within the gap and connecting the first electrode to the second electrode, wherein the first electrode of at least one of the temperature sensing elements is connected to the second electrode of an adjacent temperature sensing element by a flexible electrical conductor.

Provided herein are positive temperature coefficient (PTC) devices including interdigitated contacts. In one approach, a PTC device includes a core component, and a first contact and a second contact disposed along a first side of the core component. Each of the first and second contacts may include a frame member, and a plurality of digits extending perpendicularly from the frame member. The plurality of digits of the first contact may be interleaved with the plurality of digits of the second contact. In some embodiments, the plurality of digits of the first contact and the plurality of digits of the second contact extend along a same plane, and are arranged substantially parallel to one another. In some embodiments, a polymer PTC material layer is provided over the plurality of digits of the first and second contacts. The interleaved contact digits permit the PTC device to function as a 2-D current collector.

A protective element including (i) a PTC element having an opening passing through in the thickness direction, and (ii) a first electrode and a second electrode positioned on both main surfaces of the PTC element, the protective element characterized in that the first electrode extends from a main surface of the PTC element over an edge thereof and into the opening wherein the PTC element is not prevented from expanding even when secured by a screw or caulking.

A device may include a lead frame, where the lead frame includes a central portion, and a side pad, the side pad being laterally disposed with respect to the central portion. The device may further include a thyristor device, the thyristor device comprising a semiconductor die and further comprising a gate, wherein the thyristor device is disposed on a first side of the lead frame on the central portion. The device may also include a positive temperature coefficient (PTC) device electrically coupled to the gate of the thyristor device, wherein the PTC device is disposed on the side pad on the first side of the lead frame; and a thermal coupler having a first end connected to the thyristor device and a second end attached to the PTC device.

A PTC circuit protection device includes a PTC polymer material and two electrodes attached to the PTC polymer material. The PTC polymer material includes a polymer matrix and a particulate conductive filler dispersed in the polymer matrix. The polymer matrix is made from a polymer composition that contains a non-grafted polyolefin. The conductive filler includes tungsten carbide particles having a total carbon content that is less than 6.0 wt % based on the total weight of the tungsten carbide particles.

A surface-mountable over-current protection device comprises at least one chip, a first lead and a second lead. The chip comprises a PTC material layer and two metal electrode layers disposed on upper and lower surfaces of the PTC material layer. The first lead is bent into multiple portions comprising a first electrode connecting portion connecting to one of the two metal electrode layers of the at least one chip and a first soldering portion for surface-mounting. The second lead is bent into multiple portions comprising a second electrode connecting portion connecting to another one of the two electrode layers of the at least one chip and a second soldering portion for surface-mounting. The PTC material layer comprises crystalline polymer and conductive filler dispersed therein, and the conductive filler has a resistivity less than 500.Math.cm. The surface-mountable over-current protection device can withstand a cycle life test of 300 cycles at 20V/40A without blowout.

A surface-mountable over-current protection device comprises at least one chip, a first lead and a second lead. The chip comprises a PTC material layer and two metal electrode layers disposed on upper and lower surfaces of the PTC material layer. The first lead is bent into multiple portions comprising a first electrode connecting portion connecting to one of the two metal electrode layers of the at least one chip and a first soldering portion for surface-mounting. The second lead is bent into multiple portions comprising a second electrode connecting portion connecting to another one of the two electrode layers of the at least one chip and a second soldering portion for surface-mounting. The PTC material layer comprises crystalline polymer and conductive filler dispersed therein, and the conductive filler has a resistivity less than 500 .Math.cm. The surface-mountable over-current protection device can withstand a cycle life test of 300 cycles at 20V/40 A without blowout.

In accordance with one aspect of the present disclosure, an external unit used by being mounted on a bottom part of a motor body having at least two motor terminals has a holder, a PTC thermistor arranged on the holder, a first terminal connected to the PTC thermistor, a part of the first terminal exposed to an outside of the holder, and a second terminal electrically connected to the first terminal through the PTC thermistor and electrically connected to one of the motor terminals. The PTC thermistor is flat-plate shaped, and a surface of the PTC thermistor is directed toward a rotary shaft direction of the motor.

A fuse device including a fuse component, a first electrode, disposed on a first side of the fuse component, a second electrode, disposed on a second side of the fuse component, and a phase change component, disposed in thermal contact with the fuse component. The fuse component may comprise a fuse temperature, wherein the phase change component exhibits a phase change temperature, the phase change temperature marking a phase transition of the phase change component, and wherein the phase change temperature is less than the fuse temperature.