Abstract: A PTC device comprises a laminated substrate, a first PTC material layer, a second PTC material layer, a first metal layer and a second metal layer. The laminated substrate comprises a first conductive layer, a second conductive layer and an insulating layer laminated between the first and second conductive layers. The first PTC material layer is disposed on the first conductive layer, and the second PTC material layer is disposed on the second conductive layer. The first metal layer is disposed on the first PTC material layer, and the second metal layer is disposed on the second PTC material layer. The insulating layer has a through hole filled with PTC material to form a PTC connecting member of which one end connects to the first PTC material layer and another end connects to the second PTC material layer.

Abstract: An over-current protection device is a hexahedron comprising an upper surface, a lower surface and four lateral surfaces. The over-current protection device comprises a PTC device, a first insulating layer, a first electrode layer and a second electrode layer. The PTC device comprises a first conductive layer, a second conductive layer and a PTC material layer laminated therebetween. The first conductive layer comprises a first conductive section and a second conductive section separated by at least one trench. The first insulating layer is disposed on the first conductive layer. The first electrode layer is disposed on the first insulating layer and electrically coupled to the first conductive section. The second electrode layer is disposed on the first insulating layer and electrically coupled to the second conductive section. The trench comprises a primary portion not parallel to a longitudinal direction of the first and second electrode layers.

Abstract: An over-current protection device is a hexahedron comprising an upper surface, a lower surface and four lateral surfaces. The over-current protection device comprises a PTC device, a first insulating layer, a first electrode layer and a second electrode layer. The PTC device comprises a first conductive layer, a second conductive layer and a PTC material layer laminated therebetween. The first conductive layer comprises a first conductive section and a second conductive section separated by at least one trench. The first insulating layer is disposed on the first conductive layer. The first electrode layer is disposed on the first insulating layer and electrically coupled to the first conductive section. The second electrode layer is disposed on the first insulating layer and electrically coupled to the second conductive section. The trench comprises a primary portion not parallel to a longitudinal direction of the first and second electrode layers.

Abstract: A PTC device comprises a current and temperature sensing element, a first insulating layer, a second insulating layer, a first electrode layer and a second electrode layer. The current and temperature sensing device is a laminated structure comprising a first conductive layer, a second conductive layer and a PTC material layer. The first and second conductive layers are disposed on first and second surfaces of the PTC material layer, respectively. The second surface is opposite to the first surface. The first and second insulating layers are disposed on the first and second conductive layers, respectively. The first electrode layer is disposed on the first insulating layer and electrically connects to the first conductive layer. The second electrode layer is disposed on the second insulating layer and electrically connects to the second conductive layer. Corners of the current and temperature sensing device are provided with insulating members.

Abstract: A PTC device comprises a current and temperature sensing element, a first insulating layer, a second insulating layer, a first electrode layer and a second electrode layer. The current and temperature sensing device is a laminated structure comprising a first conductive layer, a second conductive layer and a PTC material layer. The first and second conductive layers are disposed on first and second surfaces of the PTC material layer, respectively. The second surface is opposite to the first surface. The first and second insulating layers are disposed on the first and second conductive layers, respectively. The first electrode layer is disposed on the first insulating layer and electrically connects to the first conductive layer. The second electrode layer is disposed on the second insulating layer and electrically connects to the second conductive layer. Corners of the current and temperature sensing device are provided with insulating members.

Abstract: A connector comprises a terminal and a layered circuit substrate. The layered circuit substrate connects to an end of the terminal, and comprises a PTC material layer, a first electrode layer forming an upper layer of the layered circuit substrate, and a second electrode layer forming a lower surface of the layered circuit substrate. The PTC material layer is disposed between the first and second electrode layers. The first and second electrode layers comprise first and second electrode pads which connect to a power supply, and the PTC material layer electrically connects to the first and second electrode pads to form an electrically conductive path in which the PTC material layer serves as a PTC resistor in series connection between the first and second electrode pads. When over-current or over-temperature occurs in the electrically conductive path, the PTC resistor will trip to a high resistance state.

Abstract: A PTC device comprises a current and temperature sensing element, a first insulating layer, a second insulating layer, a first electrode layer and a second electrode layer. The current and temperature sensing element is a laminated structure comprising a first electrically conductive layer, a second electrically conductive layer and a PTC material layer. The first and second electrically conductive layers are disposed on first and second surfaces of the PTC material layer. The first and second insulating layers are disposed on the first and second electrically conductive layers. The first electrode layer is disposed on the first insulating layer and electrically connects to the first electrically conductive layer. The second electrode layer is disposed on the second insulating layer and electrically connects to the second electrically conductive layer. The first and second electrode layers serve as solder attach surfaces for soldering the PTC device onto a circuit board.

Abstract: A surface mountable over-current protection device comprises a PTC material layer, first and second conductive layers, left and right electrodes, left and right conductive members, and left and right insulating members. The PTC material layer comprises a left notch at a left end and a right notch at a right end. The first conductive layer comprises a primary portion disposed on an upper surface of the PTC material layer and a secondary portion extending over the left notch, and the second conductive layer comprises a primary portion disposed on a lower surface of the PTC material layer and a secondary portion extending over the underside of the right notch. The left conductive member connects to the left electrode and the first conductive layer and isolates from the second conductive layer. The right conductive member connects to the right electrode and the second conductive layer and isolates from the first conductive layer.

Abstract: An over-current protection device comprises a PTC device and a heating element operable to heat the PTC device. The PTC device contains crystalline polymer and metal or ceramic conductive filler dispersed therein. The PTC device has a resistivity less than 0.1 ?·cm. The over-current protection device has the relation: It (heating)<Ih (60° C.)×10%, where Ih (60° C.) is a hold current of the over-current protection device at 60° C. when the heating element is not activated; It (heating) is a trip current of the over-current protection device when the heating element is activated to heat the PTC device. The PTC device has high hold current, thereby allowing a battery containing the device can be fast charged with a large current. In a specific situation, the heating element heats the PTC device to decrease the hold current of the over-current protection device of low resistivity, and accordingly the PTC device can trip by a small current.

Abstract: A surface mountable over-current protection device comprises a PTC material layer, first and second conductive layers, left and right electrodes, left and right conductive members, and left and right insulating members. The PTC material layer comprises a left notch at a left end and a right notch at a right end. The first conductive layer comprises a primary portion disposed on an upper surface of the PTC material layer and a secondary portion extending over the left notch, and the second conductive layer comprises a primary portion disposed on a lower surface of the PTC material layer and a secondary portion extending over the underside of the right notch. The left conductive member connects to the left electrode and the first conductive layer and isolates from the second conductive layer. The right conductive member connects to the right electrode and the second conductive layer and isolates from the first conductive layer.

Abstract: A connector comprises a terminal and a layered circuit substrate. The layered circuit substrate connects to an end of the terminal, and comprises a PTC material layer, a first electrode layer forming an upper layer of the layered circuit substrate, and a second electrode layer forming a lower surface of the layered circuit substrate. The PTC material layer is disposed between the first and second electrode layers. The first and second electrode layers comprise first and second electrode pads which connect to a power supply, and the PTC material layer electrically connects to the first and second electrode pads to form an electrically conductive path in which the PTC material layer serves as a PTC resistor in series connection between the first and second electrode pads. When an over-current or over-temperature event occurs in the electrically conductive path, the PTC resistor will trip to a high resistance state.

Abstract: An over-current protection device comprises a PTC device and a heating element operable to heat the PTC device. The PTC device contains crystalline polymer and metal or ceramic conductive filler dispersed therein. The PTC device has a resistivity less than 0.1 ?·cm. The over-current protection device has the relation: It (heating)<Ih (60° C.)×10%, where Ih (60° C.) is a hold current of the over-current protection device at 60° C. when the heating element is not activated; It (heating) is a trip current of the over-current protection device when the heating element is activated to heat the PTC device. The PTC device has high hold current, thereby allowing a battery containing the device can be fast charged with a large current. In a specific situation, the heating element heats the PTC device to decrease the hold current of the over-current protection device of low resistivity, and accordingly the PTC device can trip by a small current.

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: An over-current protection device comprises a PTC device, first and second electrodes, a first welding metal plate and a second welding metal plate. The PTC device comprises a first conductive layer, at second conductive layer and a PTC polymeric material layer laminated therebetween. The first electrode electrically connects to the first conductive layer. The second electrode electrically connects to the second conductive layer and is separated from the first electrode. The first welding metal plate is formed on an upper surface of the device and connects to the first electrode. The second welding metal plate is formed on the upper surface or a lower surface of the device and connects to the second electrode. The first and second welding metal plates are placed at two opposite ends of the strip-like structure, and each of them has a thickness sufficient to withstand spot-welding without significant resultant damage to the PTC device.

Abstract: An over-current protection device adapted to be soldered onto a circuit board comprises a PTC material layer, a first electrode foil, a second electrode foil, a bonding section and a metal connecting member. The PTC material layer has opposite first and second surfaces. The first electrode foil is in physical contact with the first surface, and the second electrode foil electrically connects to the second surface. Both the second electrode foil and the bonding section are disposed on bottom of the device, and the bonding section is separated from the second electrode foil. The metal connecting member is disposed on the lateral surface of the device. The second electrode foil is adapted to be soldered onto an electrode section of the circuit board. The bonding section and the metal connecting member connect to corresponding joint section of the circuit board.

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: An over-current protection device, which can be surface-mounted and stand upright on a circuit board and withstand 60 to 600 volts, comprises a PTC device, first and second electrodes. The PTC device is a laminated structure comprising first and second conductive layers and a PTC material layer. The first and second conductive layers are in physical contact with first and second planar surfaces of the PTC material layer, respectively. The first electrode is disposed on the first conductive layer. The second electrode is disposed on the second conductive layer and is separated from the first electrode. The first electrode, the second electrode and the PTC device commonly form an end surface which is substantially perpendicular to the first and second planar surfaces. The first electrode and the second electrode at the end surface serve as interfaces electrically connecting to the circuit board.

Abstract: A PTC composition comprises crystalline polymer and conductive ceramic filler dispersed therein. The crystalline polymer has a melting point less than 90° C. and comprises 5%-30% by weight of the PTC composition. The crystalline polymer comprises ethylene, vinyl copolymer or the mixture thereof. The vinyl copolymer comprises at least one of the functional group selected from the group consisting of ester, ether, organic acid, anhydride, imide or amide. The conductive ceramic filler comprises a resistivity less than 500 ??-cm and comprises 70%-95% by weight of the PTC composition. The PTC composition has a resistivity about 0.01-5 ?-cm and its resistance at 85° C. is about 103 to 108 times that at 25° C.

Abstract: An anti-surge over-current protection device comprises a PTC material layer, first and second conductive layers. The PTC material layer has opposite first and second planar surfaces. The first conductive layer is in physical contact with the first planar surface and comprises a plurality of first conductive members isolated from each other. The second conductive layer is in physical contact with the second planar surface, and comprises a plurality of second conductive members isolated from each other. The first conductive layer, the PTC material layer and the second conductive layer form a circuit containing first and second conductive paths. In the first conductive path, the PTC material layer forms a first series connection resistive component having at least two resistors. In the second conductive path, the PTC material layer forms a second series connection resistive component having at least two resistors.

Abstract: An over-current protection device adapted to be soldered onto a circuit board comprises a PTC material layer, a first electrode foil, a second electrode foil, a bonding section and a metal connecting member. The PTC material layer has opposite first and second surfaces. The first electrode foil is in physical contact with the first surface, and the second electrode foil electrically connects to the second surface. Both the second electrode foil and the bonding section are disposed on bottom of the device, and the bonding section is separated from the second electrode foil. The metal connecting member is disposed on the lateral surface of the device. The second electrode foil is adapted to be soldered onto an electrode section of the circuit board. The bonding section and the metal connecting member connect to corresponding joint section of the circuit board.