Circuit protective device and method for manufacturing the same

A method of manufacturing a circuit protecting element, the method comprising the steps of:

• forming a pair of surface electrodes on both ends of a top face of an insulating substrate;
• forming a base layer made of a mixture of diatom earth and silicone resin on the top face of the insulating substrate such that at least parts of the surface electrodes can be exposed;
• forming an element for bridging the pair of surface electrodes on a top face of the base layer, and for electrically connecting with the pair of surface electrodes;
• and
• irradiating the element with a laser beam for forming a pair of trimming grooves which are to be used for forming a blowout section, and a plurality of trimming grooves which are to be used for adjusting a resistance value, such that the element can form meanders;
• and
• forming an insulating layer for covering the element,
• wherein the trimming grooves to be used for forming the blowout section are formed before the trimming grooves to be used for adjusting the resistance value are formed.

A method of manufacturing a circuit protecting element, the method comprising the steps of:

• forming a pair of surface electrodes formed on both ends of a top face of an insulating substrate;
• forming a base layer made of a mixture of diatom earth and silicone resin on the top face of the insulating substrate such that at least parts of the surface electrodes can be exposed;
• and
• forming an element for bridging the pair of surface electrodes on a top face of the base layer, and for electrically connecting with the pair of surface electrodes,
• wherein the step of forming the element includes a step of forming a first element by a sputtering method and a step of forming a second element on a top face of the first element by a plating method.

A method of manufacturing a circuit protecting element, the method comprising the steps of:

• forming a plurality of surface electrodes on a top face of a sheet-like insulating substrate, having a plurality of vertical dividing grooves and horizontal dividing grooves, such that the surface electrodes can stride across the horizontal dividing grooves;
• forming a base layer made of a mixture of diatom earth and silicone resin on the top face of the insulating substrate such that at least parts of the surface electrodes can be exposed;
• forming a plurality of first elements for bridging a pair of the surface electrodes;
• forming a square and frame-like dummy electrode which solidly surrounds a region, where the surface electrodes and the first element are formed, and is formed of a pair of lateral dummy sections and a pair of vertical dummy sections;
• and
• forming a second element on a top face of the first element by an electrical plating method,
• wherein the step of forming the dummy electrode connects the pair of lateral dummy sections to the plurality of surface electrodes, and connects a part of the dummy electrode to a power feeder section.