Patent ID: 8803652

Claim:
A protection element for protecting a device to be protected, the protection element comprising: an insulation baseboard; a pair of electrodes provided at both ends of a top face of the insulation baseboard; a low-melting metal conductor which is disposed on the insulation baseboard, and which is adapted to be connected to a power supply path of the device to be protected, wherein the low-melting metal conductor is adapted to cause a blowout by means of a predetermined abnormal electric power, and the protection element is adapted to allow the low-melting metal conductor to blow out and shut off a current path thereof if the abnormal electric power is supplied to the device to be protected; an insulation cover which is mounted on the baseboard so as to cover the low-melting metal conductor with a predetermined space therebetween; a flux which is applied to a surface of the low-melting metal conductor and is positioned in the space; a stepped portion which is formed on a center part of an interior face of the insulation cover opposite to the low-melting metal conductor, for retaining the flux at a predetermined position in the space in direct physical contact with the flux, wherein the flux is retained at the predetermined position in the space in direct physical contact with the stepped portion due to its wettability and surface tension, wherein the insulation cover mounted on the insulation baseboard is formed in a box shape which opens at one side face, wherein a hole portion retaining the flux is formed in the low-melting metal conductor, the hole portion being a through hole formed at a center part of the low-melting metal conductor, the flux being positioned on the low-melting metal conductor so as to be in direct physical contact with at least a peripheral surface of the hole portion so as to be retained at the hole portion due to its wettability and surface tension, and wherein the stepped portion is concentrically circular and comprises a cylindrical protrusive stripe portion which is formed on the interior face of the insulation cover integrally therewith and is provided face-to-face opposite to the hole portion of the low-melting metal conductor.