Abstract: The PTC circuit protection device includes a PTC polymer material and two electrodes attached to the PTC material. The PTC polymer material includes a polymer matrix and a conductive filler dispersed in the polymer matrix. The conductive filler includes first titanium carbide particles and second titanium carbide particles. The first titanium carbide particles have an average Fisher sub-sieve particle size of less than 2.5 ?m. The second titanium carbide particles have an average Fisher sub-sieve particle size of less than 3.2 ?m.

Abstract: An over-current protection device includes first and second electrodes and a multilayered structure including first and second PTC polymer material layers that are stacked one above the other and that are bonded to each other. The first PTC polymer material layer includes a first polymer matrix and a particulate conductive filler. The second PTC polymer material layer includes a second polymer matrix and a particulate conductive filler. The second polymer matrix is made from a second polymer composition that contains. One of the first and second polymer compositions contains polyvinylidene fluoride and polyolefin and the other of the first and second polymer compositions contains polyolefin or polyvinylidene fluoride.

Abstract: A PPTC over-current protection device includes: a first PPTC component that has a first metal foil layer and a first PTC element including a first polymer matrix, the first metal foil layer being bonded to the first polymer matrix; and a second PPTC component that has a second metal foil layer and a second PTC element including a second polymer matrix. The second metal foil layer is bonded to the second polymer matrix. The first and second PPTC components are stacked one above the other and are bonded to each other to form a stack with the first and second metal foil layers being bonded to each other or with the first and second polymer matrices being bonded to each other.

Abstract: An over-current protection device includes a PTC element having opposite first and second surfaces; first and second electrode layers attached to the first and second surfaces, respectively; first and second conductive leads respectively attached to the first and second electrode layers and each having an end portion that overlaps the PTC element; and first and second heat-sink layers of a heat dissipating and electrically insulative material attached to and covering the first and second electrode layers and the end portions of the first and second conductive leads. The heat dissipating and electrically insulative material has a thermal conductivity greater than 1.7 W/mK.

Abstract: A PTC polymer composition includes a polymer component, and an electrically conductive filler component including an electro-conductive metallic particulate, an electro-conductive ceramic particulate, and an electro-conductive carbon particulate. The weight ratio of the polymer component to the filler component ranges from 1:13˜1:5.5. The weight of the metallic particulate is higher than that of the ceramic particulate, and the weight of the ceramic particulate is higher than that of the carbon particulate. The carbon particulate is present in an amount ranging from 2.8 wt % to 7.3 wt % based on the weight of the filler component.

Abstract: An insertable PPTC over-current protection device includes: first and second electrodes; a solder material; conductive lead pins bonded to the first and second electrodes, respectively, each of the lead pins having a connecting segment extending along and bonded to an outer surface of the respective one of the first and second electrodes through the solder material, and a free segment extending outwardly from the connecting segment beyond a peripheral edge of the respective one of the first and second electrodes; and a PTC polymer matrix laminated between the first and second electrodes. The PTC polymer matrix is formed with at least one hole that has an effective volume to accommodate thermal expansion of the PTC polymer matrix.

Abstract: A PTC material composition for making a PTC circuit protection device comprises a PTC polymer unit and a conductive filler containing a plurality of titanium carbide particles. The titanium carbide particles have a residual oxygen content greater than 0.3 wt % based on the weight of the titanium carbide particles.

Abstract: A method for making a positive temperature coefficient device includes: (a) forming a crosslinkable preform of a positive temperature coefficient polymer composition containing a polymer system and a conductive filler; (b) attaching a pair of electrodes to the preform; (c) soldering a pair of conductive leads to the electrodes using a lead-free solder paste having a melting point greater than 210° C.; and (d) crosslinking the crosslinkable preform after step (c).

Abstract: 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 polymermatrix is made from a polymer composition that contains a primary polymer unit and a reinforcing polyolefin. The primary polymer unit contains a base polyolefin and optionally a grafted polyolefin. The reinforcing polyolefin has a weight average molecular weight greater than that of the base polyolefin. The primary polymer unit and the reinforcing polyolefin are co-melted together and then solidified to form the polymer matrix. The base polyolefin has a melt flow rate ranging from 10 g/10 min to 100 g/10 min, and the reinforcing polyolefin has a melt flow rate ranging from 0.01 g/10 min to 1 g/10 min.

Abstract: A positive temperature coefficient polymer composition includes a polymer system and a conductive particulate filler. The polymer system includes a non-ionic copolymer of a substituted or non-substituted olefin monomer and an anhydride monomer. The olefin monomer and the anhydride monomer form a linear polymer chain.

Abstract: A PTC polymer composition contains: (a) a non-elastomeric polymer mixture in an amount from 20 wt % to 80 wt % based on the weight of the polymer composition; (b) a conductive particulate material in an amount from 20 wt % to 60 wt % based on the weight of the polymer composition; (c) a voltage resistance-enhancing agent that contains particulate metal oxide material in an amount from 1 wt % to 30 wt % based on the weight of the polymer composition; and (d) a polymer stabilizer that contains a thermoplastic elastomer in an amount from 1 wt % to 30 wt % based on the weight of the polymer composition.

Abstract: A PTC circuit protection device has a resistivity at 20° C. of less than 10 ohm-cm and is made from a PTC polymer composition that contains: 40-70 vol % of a non-cross-linked polyvinylidene fluoride (PVDF) or a cross-linked polyvinylidene fluoride formed by cross-linking the non-cross-linked polyvinylidene fluoride by irradiation to a dosage less than 8 Mrads; and 30-60 vol % of a particulate conductive filler. The non-cross-linked polyvinylidene fluoride has a melting flow rate (MFR) of less than 120 g/10 min.

Abstract: A PTC polymer composition contains a polymer mixture, a conductive particulate material, and a voltage resistance-enhancing agent of particulate metal oxide for enhancing voltage resistance of the polymer composition. The polymer mixture contains a crystalline grafted polymer and a crystalline non-grafted polymer.

Abstract: A process for making surface mountable electrical devices includes the steps of laminating two PTC sheets, two inner metal foil sheets, and two outer metal foil sheets to form a laminate such that the inner metal foil sheets are sandwiched between the PTC sheets and overlap each other and that the PTC sheets are bonded to each other, forming patterns of slits in the outer metal foil sheets, forming bores in the laminate along cutting lines, forming conductive transverse layers in interiors of the bores, and cutting the laminate along the cutting lines.

Abstract: A process for making surface mountable electrical devices includes the steps of laminating two PTC sheets, two inner metal foil sheets, and two outer metal foil sheets to form a laminate such that the inner metal foil sheets are sandwiched between the PTC sheets and overlap each other and that the PTC sheets are bonded to each other, forming patterns of slits in the outer metal foil sheets, forming bores in the laminate along cutting lines, forming conductive transverse layers in interiors of the bores, and cutting the laminate along the cutting lines.

Abstract: A surface mountable electrical devices includes a laminate body having a plurality of stacked PTC sheets, two overlapping metal foil sheets sandwiched between two adjacent ones of the PTC sheets, a conductive first electrode layer, a conductive second electrode layer spaced apart from the first electrode layer, and a conductive third electrode layer. The two adjacent ones of the PTC sheets have contact faces with inlaid portions respectively inlaid with the metal foil sheets and non-inlaid portions bonded to each other. At least a conductive transverse layer interconnects the first and third electrode layers and the metal foil sheets.

Abstract: A cocktail-type positive temperature coefficient (PTC) polymer blend composition, and a circuit protection device including a PTC element made from the cocktail-type positive temperature coefficient (PTC) polymer blend composition are disclosed. The composition includes a polymer mixture, containing a crystalline grafted polymer, a crystalline non-grafted polymer and an ionomer of an ionic copolymer of said crystalline non-grafted polymer and an ionized unsaturated carboxylic acid, and a conductive particulate material.

Abstract: A process for manufacturing surface mountable electrical devices includes the steps of preparing a PTC resistive plate, covering the plate with first and second conductive layers to form a laminate, forming a plurality of spaced apart bores of cross-shaped cross-section in the laminate along intersecting cutting lines at locations where the cutting lines intersect, electroplating the first and second conductive layers and the cross-shaped bores, and cutting the laminate along the cutting lines to form a plurality of polygonal elements with each of the bores being divided into four parts, each having a substantially L-shaped cross-section.

Abstract: A surface mountable electrical devices includes a PTC resistive element having opposite first and second surfaces and lateral faces interconnecting the first and second surfaces, spaced apart first and third electrode layers formed on the first surface, a second electrode layer formed on the second surface, and a conductive layer. Each two adjacent lateral faces defines a corner that has a terraced face. The conductive layer has a first lateral segment formed on the third electrode layer, a second lateral segment formed on the second electrode layer, and a transverse segment formed on the terraced face of one of the corners and having a terraced cross-section.

Abstract: A positive temperature coefficient (PTC) polymer blend composition, and a circuit protection device including a PTC element made from the positive temperature coefficient (PTC) polymer blend composition are disclosed. The composition includes a polymer mixture, containing a crystalline grafted polymer and a crystalline non-grafted polymer, and a conductive particulate material.