High pressure resistant surface mounted fuse

Abstract

The invention discloses a high pressure resistant surface mounted fuse, which comprises a fusing chip and a fusing body with a circular through hole in the middle, wherein the fusing chip is mainly composed of two end electrodes, a ceramic substrate, a first fusant layer and a first arc extinguishing glass layer; the end electrodes are composed of surface electrodes, back electrodes and side electrodes, a second fusant layer is arranged on the lower surface of the ceramic substrate, two back electrodes are arranged on the two sides of the second fusant layer respectively and in electrical connection with the second fusant layer; a second arc extinguishing glass layer is covered on the second fusant layer and the area in the back electrodes close to the second fusant layer; the fusing chip is arranged in the circular through hole of the fusing body, two metal covers are arranged on the two ends of the fusing body respectively and cover the circular through hole to form a closed cavity, and the end electrodes are in electrical connection with the metal covers through soldering pieces. The fuse is mounted on the surface, so that metallic vapor in the fusant layer can be absorbed uniformly by the arc extinguishing glass layer, arc discharge is reduced, risks of secondary short circuit after fusing are reduced, and insulation resistance after fusing is increased.

Description

technical field [0001] The invention relates to the technical field of fuses, in particular to a high-voltage, high-reliability surface mount fuse. Background technique [0002] Surface mount fuses are mainly used for overcurrent protection of printed circuit boards and other circuits. The principle is that when the circuit fails or is abnormal, the metal melt of the fuse itself will fuse and cut off the current to protect the circuit. [0003] Existing surface mount fuses and their manufacture include: fuses made by monolithic technology, fuses made by chip resistance technology and fuses with metal wires in the insulator. The monolithic process is to print one or more layers of melt on the ceramic green substrate through a thick film, and then cut it horizontally and vertically to form a green body of a single element, and then obtain it through co-firing, sealing and electroplating. Its advantages Its glass ceramics have strong arc extinguishing ability, so it can achiev...

AI Technical Summary

Problems solved by technology

The monolithic process is to print one or more layers of melt on the ceramic green substrate through a thick film, and then cut it horizontally and vertically to form a green body of a single element, and then obtain it through co-firing, sealing and electroplating. Its advantages Its glass ceramics have strong arc extinguishing ability, so it can achieve a large breaking capacity. The disadvantage is that its production cycle is long, and there is a risk of mutual penetration when the fuse and the green body are co-fired, resulting in poor consistency; The resistance process is a very mature process. The basic process is to first provide an insulating substrate with front and back sides. There are horizontal and vertical grooves on the substrate, so as to divide the substrate into multiple rectangular units, and then each The surface electrode, the back electrode, the melt and the protective layer covering the melt are respectively formed on the unit, the substrate is divided into multiple substrates along the longitudinal groove, and the terminal internal electrodes are formed on the two sides of each substrate. Finally, each substrate is divided into multiple rectangular units according to the transverse grooves to obtain the required chips. The advantages are simple manufacturing process, short production cycle, and mass production. The disadvantage is that it cannot be used in high-voltage, high-voltage applications. In the reliability environment; the fuse that wears a metal wire in the insulator is the most common way to pass the fuse into the cavity of the ceramic body and then connect to the terminal electrode. The advantage is that the fuse has a large breaking capacity and consistency. Well, the disadvantage is that the fuse is small and easy to break, the wire threading process is complicated, the efficiency is low, it is difficult to produce in large quantities, and the shape of the fuse can be designed limited

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