Abstract: An over-current protection device includes an electrode layer and a heat-sensitive layer. The heat-sensitive layer includes a polymer matrix and a conductive filler. The polymer matrix includes a polyolefin-based polymer and an olefin-acrylate copolymer. The polyolefin-based polymer is represented by a formula (I): ?wherein R1 and R2 are selected from the group consisting of CH3, C2H5, and C3H7. The olefin-acrylate copolymer is represented by a formula (II): ?wherein R is selected from the group consisting of COOCH3, COOC2H5, and COOC4H9.

Abstract: An over-current protection device includes an electrode layer and a heat-sensitive layer. The heat-sensitive layer exhibits a positive temperature coefficient (PTC) characteristic, and is laminated between a top metal layer and a bottom metal layer of the electrode layer. The heat-sensitive layer includes a polymer matrix and a conductive filler. The polymer matrix includes a fluoropolymer. The fluoropolymer has a plurality of spherulites, and the fractal dimension of each spherulite is lower than 12.

Abstract: An over-current protection device includes an electrode layer and a heat-sensitive layer. The heat-sensitive layer exhibits a positive temperature coefficient (PTC) characteristic, and is laminated between a top metal layer and a bottom metal layer of the electrode layer. The heat-sensitive layer includes a polymer matrix and a conductive filler. The polymer matrix includes a first fluoropolymer and a second fluoropolymer. The first fluoropolymer includes a first melting point, and the second fluoropolymer has a second melting point lower than the first melting point. The difference between the first melting point and the second melting point is smaller than 14° C. The second fluoropolymer has a second melt flow index ranging from 0.4 g/10 min to 0.7 g/10 min.

Abstract: An over-current protection device includes an electrode layer and a heat-sensitive layer. The heat-sensitive layer exhibits a positive temperature coefficient (PTC) characteristic, and is laminated between a top metal layer and a bottom metal layer of the electrode layer. The heat-sensitive layer includes a polymer matrix and a conductive filler. The polymer matrix includes a first fluoropolymer and a second fluoropolymer. The first fluoropolymer has a first volume and a first melt flow index, and the second fluoropolymer has a second volume and a second melt flow index. The second melt flow index ranges from 0.4 g/10 min to 0.7 g/10 min and is lower than the first melt flow index, and a volume ratio by dividing the second volume by the first volume ranges from 0.4 to 0.6.

Abstract: An over-current protection device includes an electrode layer and a heat-sensitive layer. The heat-sensitive layer exhibits a positive temperature coefficient (PTC) characteristic, and is laminated between a top metal layer and a bottom metal layer of the electrode layer. The heat-sensitive layer includes a polymer matrix and a conductive filler. The polymer matrix includes a first fluoropolymer and a second fluoropolymer. The weight average molecular weight of the second fluoropolymer ranges from 630000 g/mol to 1100000 g/mol. The conductive filler is dispersed in the polymer matrix, thereby forming an electrically conductive path in the heat-sensitive layer.

Abstract: An over-current protection device includes an electrode layer and a heat-sensitive layer. The heat-sensitive layer exhibits a positive temperature coefficient (PTC) characteristic, and is laminated between a top metal layer and a bottom metal layer of the electrode layer. The heat-sensitive layer includes a polymer matrix and a conductive filler. The polymer matrix includes a fluorine-containing copolymer, and its melting point ranges from 210° C. to 240° C. The conductive filler consists of carbon black solely, and is used to form an electrically conductive path in the heat-sensitive layer. In addition, the over-current protection device has a resistance-jump ratio ranging from 1.2 to 1.3 between 40° C. and 130° C.

Abstract: An over-current protection device includes an electrode layer and a heat-sensitive layer. The heat-sensitive layer contacts a top metal layer and a bottom metal layer of the electrode layer, and is laminated therebetween. In addition, the heat-sensitive layer exhibits a positive temperature coefficient (PTC) characteristic and includes a polymer matrix and a conductive filler. The polymer matrix includes a first fluoropolymer, by which the over-current protection device has a starting jump temperature of resistance ranging from 184° C. to 192° C. The conductive filler includes carbon black and a metal compound, thereby forming an electrically conductive path in the heat-sensitive layer.

Abstract: An over-current protection device includes a heat-sensitive layer and an electrode layer. The electrode layer includes a top metal layer and a bottom metal layer, and the heat-sensitive layer attached therebetween. The heat-sensitive layer exhibits a positive temperature coefficient (PTC) characteristic and includes a polymer matrix and a conductive filler. The polymer matrix includes a polyolefin-based homopolymer and a polyolefin-based copolymer. The polyolefin-based homopolymer has a first coefficient of thermal expansion (CTE), and the polyolefin-based copolymer has a second CTE lower than the first CTE. The polyolefin-based homopolymer and the polyolefin-based copolymer together form an interpenetrating polymer network (IPN).

Abstract: An over-current protection device includes first and second electrode layers and a PTC material layer laminated therebetween. The PTC material layer includes a polymer matrix, a conductive filler, and a titanium-containing dielectric filler. The polymer matrix has a fluoropolymer. The titanium-containing dielectric filler has a compound represented by a general formula of MTiO3, wherein the M represents transition metal or alkaline earth metal. The total volume of the PTC material layer is calculated as 100%, and the titanium-containing dielectric filler accounts to for 5-15% by volume of the PTC material layer.

Abstract: An over-current protection device includes first and second electrode layers and a PTC material layer laminated therebetween. The PTC material layer includes a polymer matrix, and a conductive filler. The polymer matrix has a fluoropolymer. The total volume of the PTC material layer is calculated as 100%, and the fluoropolymer accounts for 47-62% by volume of the PTC material layer. The fluoropolymer has a melt viscosity higher than 3000 Pa·s.

Abstract: An over-current protection device includes a first metal layer, a second metal layer and a heat-sensitive layer laminated therebetween. The heat-sensitive layer exhibits a positive temperature coefficient (PTC) characteristic and includes a polymer matrix and a first conductive filler. The polymer matrix includes a polyolefin-based polymer and a fluoropolymer. The fluoropolymer has a melt flow index higher than 1.9 g/10 min, and the polyolefin-based polymer and the fluoropolymer together form an interpenetrating polymer network (IPN). The first conductive filler has a metal-ceramic compound dispersed in the polymer matrix.

Abstract: An over-current protection device includes a first metal layer, a second metal layer and a heat-sensitive layer laminated therebetween. The heat-sensitive layer exhibits a positive temperature coefficient (PTC) characteristic and includes a first polymer and a conductive filler. The first polymer consists of polyvinylidene difluoride (PVDF), and PVDF exists in different phases such as ?-PVDF, ?-PVDF and ?-PVDF. The total amount of ?-PVDF, ?-PVDF and ?-PVDF is calculated as 100%, and the amount of ?-PVDF accounts for 33% to 42%.

Abstract: An over-current protection device includes a first metal layer, a second metal layer and a heat-sensitive layer laminated therebetween. The heat-sensitive layer exhibits a positive temperature coefficient (PTC) characteristic and includes a first polymer and a conductive filler. The first polymer consists of polyvinylidene difluoride (PVDF), and PVDF exists in different phases such as ?-PVDF, ?-PVDF and ?-PVDF. The total amount of ?-PVDF, ?-PVDF and ?-PVDF is calculated as 100%, and the amount of ?-PVDF accounts for 48% to 55%. The conductive filler has a metal-ceramic compound.

Abstract: An over-current protection device comprises first and second electrode layers and a PTC material layer laminated therebetween. The PTC material layer includes a polymer matrix, a conductive filler and a titanium-containing inner filler. The polymer matrix has a fluorine-free polyolefin-based polymer. The titanium-containing inner filler has a compound represented by a general formula of MTiO3, wherein the M represents transition metal or alkaline earth metal. The total volume of the PTC material layer is calculated as 100%, and the titanium-containing inner filler accounts for 1-9% by volume of the PTC material layer.

Abstract: An over-current protection device includes first and second electrode layers and a PTC material layer laminated therebetween. The PTC material layer includes a polymer matrix, a conductive filler, and a titanium-containing dielectric filler. The polymer matrix has a fluoropolymer. The titanium-containing dielectric filler has a compound represented by a general formula of MTiO3, wherein the M represents transition metal or alkaline earth metal. The total volume of the PTC material layer is calculated as 100%, and the titanium-containing dielectric filler accounts to for 5-15% by volume of the PTC material layer.

Abstract: 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 and carbon black. The polymer matrix comprises a fluoropolymer having a melting point higher than 150° C. The carbon black is dispersed in the polymer matrix. A resistance jump Rjump_1000@16V/50A of the over-current protection device at 16V/50 A by 1000 cycles is 0.80-1.20. A resistance jump Rjump_1000@25V/50A of the over-current protection device at 25V/50 A by 1000 cycles is 0.90-1.30.

Abstract: 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.

Abstract: 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 and carbon black. The polymer matrix comprises a fluoropolymer having a melting point higher than 150° C. The carbon black is dispersed in the polymer matrix. A resistance jump Rjump_1000@16V/50A of the over-current protection device at 16V/50 A by 1000 cycles is 0.80-1.20. A resistance jump R1000@16V/50A of the over-current protection device at 25V/50 A by 1000 cycles is 0.90-1.30.

Abstract: 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.

Abstract: 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, an electrically conductive filler and a metal compound filler. The PTC material layer comprises the polymer of 50-70% by volume, and the electrically conductive filler and the metal compound filler are distributed in the polymer. The metal compound filler has a particle size D50 of 2-15 ?m and 5-20% by volume and is selected from the group consisting of aluminum nitride, aluminum hydroxide, aluminum oxide, titanium oxide and zirconium oxide. The over-current protection device has a resistivity of 0.7-1.2 ?·cm.