High-square-resistance safety film having horizontal spacing bars for isolation

Abstract

The invention relates to an electrode structure of a high-square-resistance metalized safety film having horizontal spacing bars for isolation, wherein the metalized safety film is used by a capacitor. A polypropylene medium basal film is plated and coated with a zinc / aluminium metal electrode plating layer to form a composite film; and a plurality of horizontal spacing bars that are parallel to each other and are arranged at equal intervals are arranged between a blank left edge and a plating layer thickened edge of the composite layer to carry out segmented protection on contact and connection between the thickened edge and a metal spraying layer. The electrode parts between the adjacent horizontal spacing bars is thinned substantially and then ladder-shaped distribution is formed, so that the damage degree of the basal film during the evaporating and plating process can be reduced and the working field intensity of the medium is enhanced. Moreover, the energy needed by self healing is reduced substantially, thereby achieving an objective of safety self healing.

Description

technical field [0001] The invention relates to a metallized thin film material for capacitors, in particular to an improvement of a metallized safety film electrode structure for capacitors. Background technique [0002] A major shortcoming in the existing metallized film technology is that the dielectric base film is damaged during the process of evaporating electrodes and receiving high temperature and high-speed molecular precipitation of metal vapor, which makes the working field strength (or withstand voltage) of the medium Greatly reduced. Another major defect is that the connection between the thickened side of the metallized film and the gold spray is a weak link, which limits the impact current resistance and working life. And there is still no fundamental solution to these problems. [0003] In addition, the use of metallized safety film technology to improve the effectiveness of electroweak point breakdown self-healing in capacitors is well known. The metalliz...

AI Technical Summary

Problems solved by technology

It also has disadvantages: First, when breakdown and self-healing occur, although the capacitance of the isolated small electrode unit is very small, the area is about 50mm 2 , but with a normal breakdown self-healing point area of ​​0.5mm 2 In comparison, the difference is hundreds of times. Therefore, in the self-healing test of the film capacitor, the capacity loss value is many times larger than the standard index value of the ordinary metallized film capacitor, and cannot pass the test standard.

Second, when there is a voltage breakdown on the small electrode unit block, although there are externally connected narrow strips of coating to protect against fusing, many externally connected narrow strips of coating that have not been fused under normal operation are operated by the charging and discharging of the capacitor. When the current gathers and flows, the current density is much higher than that of the surrounding electrodes, which makes the narrow strip of the coating become a heating point. Due to the heating, the dielectric withstand voltage will inevitably be reduced, thereby reducing the dielectric working field strength of the capacitor.

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