The present invention provides a protection device including a bimetal component and a PTC component. This protection device includes a resin base, a first terminal, a second terminal, a PTC component, a bimetal component, an arm, an upper plate and a resin cover. A portion of the first terminal configures a first electrode, and a portion of a second terminal configures the second electrode, and the first electrode and the second electrode are exposed outward at the bottom surface of the resin base. In a normal state, the first terminal, the arm and the second terminal are electrically connected in series. When the bimetal component is activated, the first terminal and the arm become electrically cut off while the first terminal, the PTC component, the bimetal component, the arm and the second terminal are electrically connected in series in the mentioned order.

The present invention provides a protection device including a bimetal component and a PTC component. This protection device includes a resin base, a first terminal, a second terminal, a PTC component, a bimetal component, an arm, an upper plate and a resin cover. A portion of the first terminal configures a first electrode, and a portion of a second terminal configures the second electrode, and the first electrode and the second electrode are exposed outward at the bottom surface of the resin base. In a normal state, the first terminal, the arm and the second terminal are electrically connected in series. When the bimetal component is activated, the first terminal and the arm become electrically cut off while the first terminal, the PTC component, the bimetal component, the arm and the second terminal are electrically connected in series in the mentioned order.

A reflowable thermal fuse comprises a conduction element with first and second elastic portions, a sensor, a restraining element, a heating element and mounting pads. The first elastic portion is adapted to apply force on the conduction element in an activated state of the thermal fuse. The sensor is in mechanical communication with the first elastic portion of the conduction element. The restraining element is adapted to secure the second elastic portion of the conduction element and thereby prevent the second elastic portion from applying force on the conduction element in an installation state of the thermal fuse. Application of an activating current through the heating element causes heat generated and transferred to the restraining element and makes the restraining element to lose resilience, thereby releasing the second elastic portion and placing the thermal fuse in the activated state. The sensor loses its ability to hold the first elastic portion in place and allows the conduction element to open during a subsequent fault condition.

A reflowable thermal fuse comprises a conduction element with first and second elastic portions, a sensor, a restraining element, a heating element and mounting pads. The first elastic portion is adapted to apply force on the conduction element in an activated state of the thermal fuse. The sensor is in mechanical communication with the first elastic portion of the conduction element. The restraining element is adapted to secure the second elastic portion of the conduction element and thereby prevent the second elastic portion from applying force on the conduction element in an installation state of the thermal fuse. Application of an activating current through the heating element causes heat generated and transferred to the restraining element and makes the restraining element to lose resilience, thereby releasing the second elastic portion and placing the thermal fuse in the activated state. The sensor loses its ability to hold the first elastic portion in place and allows the conduction element to open during a subsequent fault condition.

To spread flux evenly across the entire surface of a rectangular meltable conductor, a protective element includes: an insulating substrate; a heat-generating resistor disposed on the insulating substrate; a first and a second electrodes laminated onto the insulating substrate; a heat-generating element extracting electrode overlapping the heat-generating resistor in a state electrically insulated therefrom and electrically connected to the heat-generating resistor on a current path between the first and the second electrodes; a rectangular meltable conductor laminated between the heat-generating element extracting electrode and the first and the second electrodes for interrupting a current path between the first electrode and the second electrode by being melted by heat; and a plurality of flux bodies disposed on the meltable conductor; wherein the flux bodies are disposed along the heat-generating resistor.

To spread flux evenly across the entire surface of a rectangular meltable conductor, a protective element includes: an insulating substrate; a heat-generating resistor disposed on the insulating substrate; a first and a second electrodes laminated onto the insulating substrate; a heat-generating element extracting electrode overlapping the heat-generating resistor in a state electrically insulated therefrom and electrically connected to the heat-generating resistor on a current path between the first and the second electrodes; a rectangular meltable conductor laminated between the heat-generating element extracting electrode and the first and the second electrodes for interrupting a current path between the first electrode and the second electrode by being melted by heat; and a plurality of flux bodies disposed on the meltable conductor; wherein the flux bodies are disposed along the heat-generating resistor.

A heat-reactive switch includes an airtight container with a housing and a lid plate, two conductive terminal pins fixed in through-holes in the lid plate, a fixed contact point fixed on one of the conductive terminal pins, a heater connected to the other conductive terminal pin and to the lid plate, a heat-reactive plate connected to the housing internal surface, the bending direction becoming inverted at a predetermined temperature, and a mobile contact point provided at the end of the heat-reactive plate. A heating element has a plurality of serpentine portions made from a metal plate in ribbon form, disposed between the lid plate and the heat-reactive plate so as to be parallel thereto. At least two of the serpentine portions are disposed to face each other while sandwiching the conductive terminal pin. Each portion follows the inner peripheral surface of the housing and have planar portions facing each other.

A heat-reactive switch includes an airtight container with a housing and a lid plate, two conductive terminal pins fixed in through-holes in the lid plate, a fixed contact point fixed on one of the conductive terminal pins, a heater connected to the other conductive terminal pin and to the lid plate, a heat-reactive plate connected to the housing internal surface, the bending direction becoming inverted at a predetermined temperature, and a mobile contact point provided at the end of the heat-reactive plate. A heating element has a plurality of serpentine portions made from a metal plate in ribbon form, disposed between the lid plate and the heat-reactive plate so as to be parallel thereto. At least two of the serpentine portions are disposed to face each other while sandwiching the conductive terminal pin. Each portion follows the inner peripheral surface of the housing and have planar portions facing each other.

In a protective circuit substrate having a circuit substrate and a protective element, the protective element including: an insulating substrate; a heat-generating element; first and second electrodes laminated on the insulating substrate; a first and second connecting terminals provided on one side edge of a mounting surface to be mounted to the circuit substrate, the first connecting terminals being continuous with the first and second electrodes; a heat-generating element extracting electrode provided in a current path between the first and second electrodes and electrically connected to the heat-generating element; and a meltable conductor provided between the first and second electrodes, wherein the circuit substrate includes a region for mounting the protective element in which no electrode pattern other than a connecting electrode to the protective element is provided.

In a protective circuit substrate having a circuit substrate and a protective element, the protective element including: an insulating substrate; a heat-generating element; first and second electrodes laminated on the insulating substrate; a first and second connecting terminals provided on one side edge of a mounting surface to be mounted to the circuit substrate, the first connecting terminals being continuous with the first and second electrodes; a heat-generating element extracting electrode provided in a current path between the first and second electrodes and electrically connected to the heat-generating element; and a meltable conductor provided between the first and second electrodes, wherein the circuit substrate includes a region for mounting the protective element in which no electrode pattern other than a connecting electrode to the protective element is provided.