Abstract: The present invention provides a novel method for electrical connection between a polymer PTC device and a metal lead element to thereby prevent the problems of the connection by caulking or soldering. For this purpose, the present invention provides a process for producing a connection structure by laser welding, said connection structure having (A) a PTC device (10) including (i) a laminar polymer PTC element (12) and (ii) a metal foil electrode (14) disposed on a main surface of the laminar polymer PTC element (12), and (B) a metal lead element (20) electrically connected to the metal foil electrode. The metal foil electrode (14) has at least two metal layers, one of which, the X-th layer, has laser beam absorption a % that is the lowest among the metal layers of the metal foil electrode (14). The X-th layer is present between a first metal layer (18) of the metal foil electrode and the laminar polymer PTC element (12).

Abstract: The present invention provides a novel method for electrical connection between a polymer PTC device and a metal lead element to thereby prevent the problems of the connection by caulking or soldering. For this purpose, the present invention provides a process for producing a connection structure by laser welding, said connection structure having (A) a PTC device (10) including (i) a laminar polymer PTC element (12) and (ii) a metal foil electrode (14) disposed on a main surface of the laminar polymer PTC element (12), and (B) a metal lead element (20) electrically connected to the metal foil electrode. The metal foil electrode (14) has at least two metal layers, one of which, the X-th layer, has laser beam absorption a % that is the lowest among the metal layers of the metal foil electrode (14). The X-th layer is present between a first metal layer (18) of the metal foil electrode-and the laminar polymer PTC element (12).

Abstract: An electrical device comprising a pair of electrodes, three substrates, and PTC elements inserted between the substrates, each PTC element having metal layers on both surfaces, in which each of the outer substrates has a metal layer on the inner surface, the two metal layers being electrically connected to one of the electrodes and in electrical contact with the respective metal layers of the PTC elements facing said metal layers of the outer substrates, and the center substrate has a metal layer on both surfaces, such metal layers being electrically connected to the other electrode and in electrical contact with the respective metal layers of the PTC elements facing said metal layers of the center substrate. This electrical device can increase the area of the PTC elements without increasing the projected area as a whole.

Abstract: An electrical device comprising a pair of electrodes, three substrates, and PTC elements inserted between the substrates, each PTC element having metal layers on both surfaces, in which each of the outer substrates has a metal layer on the inner surface, the two metal layers being electrically connected to one of the electrodes and in electrical contact with the respective metal layers of the PTC elements facing said metal layers of the outer substrates, and the center substrate has a metal layer on both surfaces, such metal layers being electrically connected to the other electrode and in electrical contact with the respective metal layers of the PTC elements facing said metal layers of the center substrate. This electrical device can increase the area of the PTC elements without increasing the projected area as a whole.