An over-current protection device comprises first and second electrode layers and a PTC material layer laminated therebetween. The PTC material layer comprises a polymer matrix, a conductive ceramic filler, a carbon-containing conductive filler, and an inner filler. The polymer matrix comprises a fluoropolymer having a melting point higher than 150° C. The inner filler is selected from one of aluminum nitride, silicon carbide, zirconium oxide, boron nitride, graphene, aluminum oxide, or any mixtures thereof, and comprises 2-10% by volume of the PTC material layer. The over-current protection device is able to mitigate negative temperature coefficient (NTC) behavior after trip of device, and achieves high hold current and high endurable power.

A circuit protection device including a positive temperature coefficient (PTC) device and a backup fuse electrically connected in series with one another, the backup fuse comprising a quantity of solder disposed on a dielectric chip and having a melting temperature that is higher than a trip temperature of the PTC device, wherein the a surface of the dielectric chip exhibits a de-wetting characteristic relative to the solder such that, when the solder is melted, the solder draws away from the surface to create a galvanic opening in the backup fuse.

A thermal sensor wire. The thermal sensor wire may include a thermal sensing portion extending along a wire axis of the thermal sensor wire; and a carrier portion, the carrier portion extending along the wire axis, adjacent to the thermal sensing portion, the thermal sensing portion comprising a polymer positive temperature coefficient (PPTC) material or a negative temperature coefficient (NTC) material.

A polymer positive temperature coefficient (PPTC) material may include a polymer matrix, the polymer matrix defining a PPTC body; and a graphene filler component, disposed in the polymer matrix, wherein the graphene filler component comprises a plurality of graphene particles aligned along a predetermined plane of the PPTC body.

The invention relates to a switch including a switch housing, a contact system and a base disposed in the switch housing, a resistive element for diagnosing a state of a switch, and at least two terminals leading from the base. The resistive element has a specific resistance value. The resistive element is a conductive material formed on the base, the terminals being electrically connected by the conductive material.

A surface-mountable over-current protection device comprises at least one PTC material layer, a first conductive layer, a second conductive layer, a first electrode, a second electrode, an insulating layer, and a cover layer. The PTC material layer comprises crystalline polymer and conductive fillers dispersed therein. The first conductive layer and the second conductive layer are disposed on a first surface and a second surface of the PTC material layer, respectively. The first electrode and the second electrode are electrically connected to the first conductive layer and the second conductive layer, respectively. The insulating layer is disposed between the first electrode and the second electrode for insulation. The cover layer includes a fluorine-containing polymer, and wraps around an entire outer surface of the surface-mountable over-current protection device.

A resistance heater may include a polymer positive temperature coefficient (PPTC) material, arranged in a ring shape that defines a heater body; and an electrode assembly, comprising two or more electrodes arranged in contact with the heater body at two or more locations, wherein PPTC material comprises: a polymer matrix, the polymer matrix defining a PPTC body; and a conductive filler component, disposed in the polymer matrix.

A chip ceramic semiconductor electronic component includes a ceramic body including a ceramic semiconductor, and a first surface and a second surface in contact with the first surface, the first outer electrode on the first surface of the ceramic body, and the second outer electrode covering the first outer electrode and extending onto the second surface of the ceramic body, in which an area of a first surface of the first outer electrode is less than about 0.17 mm.sup.2, and a hard particle made of a material harder than the first outer electrode is at the interface between the first and second outer electrodes.

A composite circuit protection device includes: a first positive temperature coefficient (PTC) component; a first voltage-dependent resistor (VDR); a second VDR; and a plurality of conductive leads that correspondingly connect to the first PTC component, the first VDR and the second VDR. The second VDR and the first PTC component are electrically connected in series, the first VDR is electrically connected to the series connection of the first PTC component and the second VDR in parallel, and the first VDR has a varistor voltage greater than that of the second VDR as determined at 1 mA.

Structurally supported positive temperature coefficient (PTC) materials are disclosed. Furthermore, methods to provide structurally supported PTC materials are disclosed. In one implementation, a structurally supported PTC material includes a support structure that is at least partially covered by a PTC material. In one example, the support structure is a mesh material integrated at least partially in the PTC material.