Fuse Resistor, and discharging-type surge absorbing device with security mechanism

A fuse resistor comprising:

• an insulating substrate having a first and a second surface;
• a heat-generating resistant film being formed on said insulating substrate;
• a metal film being formed on said insulating substrate;
• a first circuit connected to said metal film;
• a thermoplastic film being formed on said metal film;
• said heat-generating resistant film being connected to a second circuit;
• said heat-generating resistant film being heated when a first current of more than a predetermined value is applied to said second circuit, whereby said insulating substrate is fractured by heat from said heat-generating resistant film when said first current exceeds said predetermined value, thereby breaking said second circuit;
• at least a portion of said metal film being melted when a second current of less than said predetermined value is applied to said second circuit;
• said thermoplastic film being melted after said at least a portion melts, whereby said thermoplastic film fills a gap in said metal film;
• and
• said first circuit being opened by said gap.

A discharging-type surge absorbing element with a security mechanism, comprising:

• an insulating substrate;
• a pair of heat-generating resistant films being formed on said insulating substrate;
• a pair of discharging surge absorbing electrode films being formed on said insulating substrate;
• a cover;
• said pair of heat-generating resistant films having a discharging space therebetween;
• said pair of discharging surge absorbing electrode films being connected to an external circuit;
• said pair of discharging surge absorbing electrode films being further connected to said pair of heat-generating resistant films;
• said cover covering said insulating substrate to form a space filled with a discharge gas;
• said pair of heat-generating resistant films being heated when a first overcurrent of more than a predetermined value is applied to said external circuit, whereby said insulating substrate is fractured by heat from said heat-generating resistant film when said overcurrent exceeds said predetermined value, thereby breaking said circuit;
• and
• said pair of heat-generating resistant films having physical properties effective for fracturing said insulating substrate.

A discharging-type surge absorbing element with a security mechanism comprising:

• an insulating substrate;
• a pair of terminals formed on said insulating substrate;
• a pair of heat-generating resistant films each connected to a one of said pair of terminals;
• a cap on said insulating substrate;
• a pair of discharging surge absorbing electrodes in said cap and connected to said pair of terminals;
• said pair of heat generating resistant films having a tiny discharging space therebetween;
• said cap covering said insulating substrate to produce a space;
• said space being filled with a discharge gas;
• said pair of discharging electrodes having a discharging space therebetween;
• and
• said insulating substrate having a recess corresponding to said tiny discharging space.