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 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 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 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 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.

Abstract: A secondary battery supplying electrical power to a load comprises a battery unit, at least one PTC temperature sensing device and a load switch. The battery unit is encompassed by a battery shell. The PTC temperature sensing device is disposed on a primary surface of the battery shell to effectively sense a temperature of the battery unit. The load switch connects to the battery unit and a load and determines whether the battery unit and the load switch are in electrical connection or in an open circuit state upon resistance variation of the PTC temperature sensing device. When the resistance of the PTC temperature sensing device increases by a threshold times within a specific temperature variation or time period, the load switch receives a control signal and accordingly switches to an open circuit state.

Abstract: A secondary battery supplying electrical power to a load comprises a battery unit, at least one PTC temperature sensing device and a load switch. The battery unit is encompassed by a battery shell. The PTC temperature sensing device is disposed on a primary surface of the battery shell to effectively sense a temperature of the battery unit. The load switch connects to the battery unit and a load and determines whether the battery unit and the load switch are in electrical connection or in an open circuit state upon resistance variation of the PTC temperature sensing device. When the resistance of the PTC temperature sensing device increases by a threshold times within a specific temperature variation or time period, the load switch receives a control signal and accordingly switches to an open circuit state.

Abstract: A radial-leaded over-current protection device includes a PTC device, first and second electrode leads and an insulating encapsulation layer. The PTC device has first and a second conductive layers and a PTC material layer therebetween. The PTC material layer has a resistivity less than 0.18 ?-cm and includes crystalline polymer and conductive ceramic filler. The ceramic filler has a resistivity less than 500 ?-cm and is 35-65% by volume of the PTC material layer. The first electrode lead has an end connecting to the first conductive layer, whereas the second electrode lead has an end connecting to the second conductive layer. The insulating encapsulation layer wraps the PTC device and the ends of the conductive layers. The radial-leaded over-current protection device at 25° C. has a value of hold current thereof divided by an area of the PTC device ranging from 0.027-0.3A/mm2. Each electrode lead has a cross-sectional area of at least 0.16 mm2.

Abstract: A radial-leaded over-current protection device includes a PTC device, first and second electrode leads and an insulating encapsulation layer. The PTC device has first and a second conductive layers and a PTC material layer therebetween. The PTC material layer has a resistivity less than 0.18 ?-cm and includes crystalline polymer and conductive ceramic filler. The ceramic filler has a resistivity less than 500 ?-cm and is 35-65% by volume of the PTC material layer. The first electrode lead has an end connecting to the first conductive layer, whereas the second electrode lead has an end connecting to the second conductive layer. The insulating encapsulation layer wraps the PTC device and the ends of the conductive layers. The radial-leaded over-current protection device at 25° C. has a value of hold current thereof divided by an area of the PTC device ranging from 0.027-0.3 A/mm2. Each electrode lead has a cross-sectional area of at least 0.16 mm2.

Abstract: A surface-mountable over-current protection device comprises a PTC material layer, first and second conductive layers, first and second electrodes, first and second electrically conductive connecting members. The PTC material layer has a resistivity less than 0.18 ?-cm. The conductive layers are in contact with opposite surfaces of the PTC material layer. The first electrode comprises pair of first metal foils and is insulated from the second conductive layer. The second electrode comprises a pair of second metal foils and is insulated from the first conductive layer. The first electrically conductive connecting member connects to the first metal foils and conductive layer. The second electrically conductive connecting member connects to the second metal foils and conductive layer. The first electrically conductive connecting member comprises 40%-100% by area of the first lateral surface, and the second electrically conductive connecting member comprises 40%-100% by area of the second lateral surface.

Abstract: A surface-mountable over-current protection device comprises one PTC material layer, first and second connecting conductors, first and second electrodes and an insulating layer. The PTC material layer has a resistivity less than 0.2 ?-cm, and comprises crystalline polymer and conductive filler dispersed therein. The first and second connecting conductors are capable of effectively dissipating heat generated from the PTC material layer. The first and second electrodes are electrically connected to first and second surfaces of the PTC material layer through the first and second connecting conductors, respectively. The dissipation factor depending on the ratio of the total area of the electrodes and the conductors to the area of the PTC material layer is greater than 0.6. At 25° C., the value of the hold current of the device divided by the product of the area of the PTC material layer and the number of the PTC material layer is greater than 1A/mm2.

Abstract: A surface-mountable over-current protection device comprises one PTC material layer, first and second connecting conductors, first and second electrodes and an insulating layer. The PTC material layer has a resistivity less than 0.2 ?-cm, and comprises crystalline polymer and conductive filler dispersed therein. The first and second connecting conductors are capable of effectively dissipating heat generated from the PTC material layer. The first and second electrodes are electrically connected to first and second surfaces of the PTC material layer through the first and second connecting conductors, respectively. The dissipation factor depending on the ratio of the total area of the electrodes and the conductors to the area of the PTC material layer is greater than 0.6. At 25° C., the value of the hold current of the device divided by the product of the area of the PTC material layer and the number of the PTC material layer is greater than 1A/mm2.

Abstract: An over-current protection device is disposed on a circuit board and configured to protect a battery. The over-current protection device includes a resistive device, at least one insulation layer and a weld electrode layer. The resistive device exhibits positive temperature coefficient behavior. The insulation layer has a thickness of at least 0.03 mm. The weld electrode layer is configured to weld a strip interconnect member to electrically coupled to the battery, and has a thickness of at least 0.03 mm. The insulation layer and the resistive device are disposed between the weld electrode layer and the circuit board. The circuit board, the resistive device and the weld electrode layer are electrically coupled in series. The association of the resistive device and the weld electrode layer has a thermal mass capable of withstanding welding the strip interconnect member without significant damage to the over-current protection device.

Abstract: A surface-mountable over-current protection device comprises a PTC material layer, first and second conductive layers, first and second electrodes, first and second electrically conductive connecting members. The PTC material layer has a resistivity less than 0.18 ?-cm. The conductive layers are in contact with opposite surfaces of the PTC material layer. The first electrode comprises a pair of first metal foils and is insulated from the second conductive layer. The second electrode comprises a pair of second metal foils and is insulated from the first conductive layer. The first electrically conductive connecting member connects to the first metal foils and conductive layer. The second electrically conductive connecting member connects to the second metal foils and conductive layer. The first electrically conductive connecting member comprises 40%-100% by area of the first lateral surface, and the second electrically conductive connecting member comprises 40%-100% by area of the second lateral surface.

Abstract: An over-current protection device is disposed on a circuit board and configured to protect a battery. The over-current protection device includes a resistive device, at least one insulation layer and a weld electrode layer. The resistive device exhibits positive temperature coefficient behavior. The insulation layer has a thickness of at least 0.03 mm. The weld electrode layer is configured to weld a strip interconnect member to electrically coupled to the battery, and has a thickness of at least 0.03 mm. The insulation layer and the resistive device are disposed between the weld electrode layer and the circuit board. The circuit board, the resistive device and the weld electrode layer are electrically coupled in series. The association of the resistive device and the weld electrode layer has a thermal mass capable of withstanding welding the strip interconnect member without significant damage to the over-current protection device.

Abstract: A surface-mounted over-current protection device with positive temperature coefficient (PTC) behavior is disclosed. The surface-mounted over-current protection device comprises a first metal foil, a second metal foil corresponding to the first metal foil, a PTC material layer stacked between the first metal foil and the second metal foil, a first metal electrode, a first metal conductor electrically connecting the first metal foil to the first metal electrode, a second metal electrode corresponding to the first metal electrode, a second metal conductor electrically connecting the second metal foil to the second metal electrode, and at least one insulated layer to electrically insulate the first metal electrode from the second metal electrode. The surface-mounted over-current protection device, at 25° C., indicates that a hold current thereof divided by the product of a covered area thereof and the number of the conductive composite module is at least 0.16 A/mm2.