A fuse device and a fuse element having excellent rapid blowout properties and excellent insulation properties after blowout even in a size-reduced fuse device are provided. A fuse element constitutes a current path of a fuse device and blows out due to self-generated heat when a rating-exceeding current flows, a length W in a width direction perpendicular to a conduction direction being greater than a total length L in the conduction direction in the fuse element. In particular, the fuse element includes a low melting point metal layer and a high melting point metal layer, the low melting point metal layer eroding the high melting point metal layer when current flows to cause blowout.

A protective element includes: an insulating substrate; a heat-generating element formed on the insulating substrate; first and second electrodes formed on side edges of a front surface of the insulating substrate; first and second connecting terminals provided on the back surface of the insulating substrate and being continuous with the electrodes; through-holes penetrating the front and back surfaces of the insulating substrate to connect the electrodes to the connecting terminals respectively; a heat-generating element extracting electrode electrically connected to the heat-generating element; and a meltable conductor laminated on a region extending from the heat-generating element extracting electrode to the electrodes and to be melted by heat to interrupt the current path between the electrodes; wherein the through-holes are formed at a central portion of the side edges of the insulating substrate on which the electrodes are formed.

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.

Disclosed is an SMD micro mixed fuse with a thermal fuse function that stably operates at high voltage surges and can interrupt electrical current at a predetermined temperature. The SMD micro mixed fuse includes: a fuse substrate provided with a first electrode and a second electrode; a variator layer formed on a front surface of the fuse substrate; a first contact terminal and a second contact terminal respectively arranged at a first side and a second side of a front surface of the varistor layer and respectively connected to the first electrode and the second electrode; at least one thermal fuse that is arranged on the front surface of the variator layer, is not connected to the first and second contact terminals, but is connected to the fuse substrate; and a fusible element that is wire-bonded to the first and second contact terminals and is not connected to the thermal fuse.

A protection device comprises a substrate, a fusible element and a heating element. The substrate comprises a first electrode and a second electrode on its surface. The fusible element is disposed on the substrate and connects to the first electrode and the second electrode at two ends. The fusible element comprises a first metal layer and a second metal layer disposed on the first metal layer. The second metal layer has a lower melting point than that of the first metal layer. The heating element is disposed on the substrate. In the event of over-voltage or over-temperature, the heating element heats up to melt and blow the fusible element. The second metal layer is 40-95% of the fusible element in thickness.

A protection device comprises a substrate, a fusible element and a heating element. The substrate comprises a first electrode and a second electrode on its surface. The fusible element is disposed on the substrate and connects to the first electrode and the second electrode at two ends. The fusible element comprises a first metal layer and a second metal layer disposed on the first metal layer. The second metal layer has a lower melting point than that of the first metal layer. The heating element is disposed on the substrate. In the event of over-voltage or over-temperature, the heating element heats up to melt and blow the fusible element. The second metal layer is 40-95% of the fusible element in thickness.

To provide a power converter and a breaking mechanism which can break a DC current and can suppress that a fused material scatter to other circuits at fusing, in the case the breaking mechanism of excess current is formed by a circuit pattern of a circuit board. A breaking mechanism is formed by a multilayer circuit board, and is provided with one or two fuse patterns which fuse when excessive current flows, and a scattering prevention pattern, wherein the one or two fuse patterns are provided in an inner layer, and wherein the scattering prevention pattern is provided in a layer different from the one or the two fuse patterns, and overlaps with at least a part of a fusing part of each of the one or two fuse patterns, viewing in a normal direction of a circuit board face.

To provide a power converter and a breaking mechanism which can break a DC current and can suppress that a fused material scatter to other circuits at fusing, in the case the breaking mechanism of excess current is formed by a circuit pattern of a circuit board. A breaking mechanism is formed by a multilayer circuit board, and is provided with one or two fuse patterns which fuse when excessive current flows, and a scattering prevention pattern, wherein the one or two fuse patterns are provided in an inner layer, and wherein the scattering prevention pattern is provided in a layer different from the one or the two fuse patterns, and overlaps with at least a part of a fusing part of each of the one or two fuse patterns, viewing in a normal direction of a circuit board face.

An electronic assembly, has at least one circuit board with conductor tracks, at least one current-limiting arrangement in the form of a thermal predetermined breaking point in at least one of the conductor tracks, and a fire-containment device in the region of the current-limiting arrangement.

A circuit board with integrated fusing includes an insulating substrate having a circuit trace formed on a surface thereof, the circuit trace including a first circuit trace portion and a second circuit trace portion. A fusible link electrically connects the first circuit trace portion to the second circuit trace portion, the fusible link including a planar surface extending from the first circuit trace portion to the second circuit trace portion. A dielectric reflow encapsulates the fusible link on the planar surface from the first circuit trace portion to the second circuit trace portion.