A novel polymer positive temperature coefficient (PPTC) material, device, and method of fabrication. One example of polymer positive temperature coefficient (PPTC) includes a polymer matrix, the polymer matrix comprising a first polymer. The PPTC material may further include a conductive filler, disposed in the polymer matrix; and at least one polymer filler, dispersed within the polymer matrix. The at least one polymer filler may comprise a second polymer, different from the first polymer, wherein the at least one polymer comprises a first melting temperature, and wherein the second polymer comprises a second melting temperature, the second melting temperature exceeding the first melting temperature by at least 20 C.

A conductive nanocomposite which contains a mixed polymer matrix which contains a rubber and a polyether, carbon nanoparticles, and transition metal nanoparticles. The conductive nanocomposite has a nonlinear relationship between resistivity and temperature characterized by an exponential increase reaching a peak resistivity followed by an exponential decrease as temperature increases. Also disclosed is a method of forming the conductive nanocomposite involving mixing the components, aging, and pressing. The conductive nanocomposite forms a component of a heater that is self-regulating as a result of the nonlinear relationship between resistivity and temperature of the conductive nanocomposite. The nanocomposite also forms a component of a thermistor.

A polymeric positive temperature coefficient (PPTC) tank heater features a first conductive region, a heater body, and a second conductive region, forming a sandwich. The first conductive region includes a first conductive surface connected to a first lead and a second conductive surface connected to a second lead. The heater body is a PPTC polymer matrix including a conductive filler and a semi-crystalline polymer. The sandwich includes multiple heating elements connected in series and each heating element supplies a different resistance.

A positive temperature coefficient (PTC) composition having a first thermally active polymer having a melting point of 30-70° C. and providing a first PTC in a lower temperature range below 70° C., and a second thermally active polymer having a melting point of 70-140° C. and providing a second PTC in a higher temperature range above 70° C., the composition also having conductive particles; and an organic solvent with a boiling point higher than 100° C., solvent being capable of dissolving both the first and second thermally active polymer. The PTC composition has two distinct PTC characteristics at the two different temperature ranges.

An over-current protection device includes a resistor element, an outer electrode, and an encapsulation layer. The resistor element has a first insulation layer, a first electrically conductive layer, a PTC material layer, a second electrically conductive layer and a second insulation layer stacked sequentially from bottom to top. The first insulation layer has a. bottom surface and a first sidewall adjoining the bottom surface. The outer electrode has a first electrode and a second electrode disposed on the bottom surface. The first and second electrodes are electrically connected to the first conductive layer through the first and second vias, respectively. The encapsulation layer covers the first sidewall of the first insulation layer and extends to a part of the bottom surface, thereby forming a first perimeter on the bottom surface of the first insulation layer. The first and second electrodes are located inside the first perimeter.

A novel polymer positive temperature coefficient (PPTC) material, device, and method of fabrication. The PPTC device may include a PPTC body; a first electrode disposed on a first surface of the PPTC body and a second electrode disposed on a second surface of the PPTC body, opposite the first electrode. The PPTC body may include a polymer matrix; and a conductive filler, disposed in the polymer matrix. The conductive filler may include a tungsten carbide component comprising at least 30 volume percent of the PPTC body; and a carbon component, wherein a total volume fraction of the conductive filler comprises between forty volume percent and sixty five volume percent of the PPTC body.

A hybrid circuit protection device includes a positive temperature coefficient (PTC) component, a voltage-dependent resistor, a gas discharge tube (GDT), and first and second conductive leads that are respectively connected to the PTC component and the GDT. The voltage-dependent resistor and the PTC component are electrically connected in series, the GDT is electrically connected to the voltage-dependent resistor and the PTC component, and the GDT has a breakdown voltage greater than a varistor voltage of the voltage-dependent resistor as determined at 1 mA.

A pPTC heating device having areas with different power densities distributed over the surface of the device. The device is constructed using a base layer composed of a pPTC material having a layer of sectioned conductive plates disposed over and under the layer of pPTC such as to control the path of the current through the device, thereby controlling resistance of the device and the power density of the device.

A novel heater is disclosed for a temperature sensitive actuator. The heater is a polymeric positive temperature coefficient (PPTC) device consisting of conductive filler and semi-crystalline polymer. The PPTC heater is strategically designed to have a predetermined self-regulation temperature suited to whatever application utilizes the heater. Physical characteristics of the PPTC heater, such as gap width and thickness, enable the current flow through the heater to be strategically controlled.

A PTC circuit protection device includes a PTC polymeric layer; a first electrically conductive layer electrically connected to the PTC polymeric layer; a second electrically conductive layer electrically connected to the PTC polymeric layer; an insulation layer unit disposed on the first and second electrically conductive layers; a first electrode formed on the insulation layer unit and electrically connected to the first electrically conductive layer; and a second electrode formed on the insulation layer unit and electrically connected to the second electrically conductive layer, wherein the first electrode is formed with a first recess.