Vertically-partitioned metallized grid safe film electrode structure

Abstract

The invention relates to a vertically-partitioned metallized grid safe film electrode structure, which comprises an upper layer metallized safe film and a lower layer metallized safe film. One side of each layer of the metallized safe films is a clad layer-free residual side, and the other side of each layer of the metallized safe films is a clad layer-thickened side; continuous clad layer zones and grid pattern zones which have roughly equal width are vertically distributed on a clad layer between the residual side and thickened side at intervals and alternately; small electrodes in the gridpattern zones do not interconnect directly; when two layers of the metallized safe films are overlaid for wrapping a capacitor, the residual sides and the clad layer-thickened sides of the upper and lower layers correspond to each other alternately; and the continuous clad layer zones and the grid pattern zones of the upper and lower layers correspond to each other alternately at the same time. The vertically-partitioned metallized grid safe film electrode structure has small overall heat productivity, is suitable for manufacturing alternating-current capacitors and high-frequency capacitors,increases safe reliability and service life, reduces the loss rate of the effective area of the film due to the gap stripes of an pattern, and reduces the manufacturing cost of a safe film capacitor.

Description

technical field [0001] The invention relates to a metallized safety film suitable for making AC and high-frequency capacitors, in particular to an improvement of the electrode structure of the metallized safety film. Background technique [0002] In the field of film capacitors, metallized safety film technology is well known. It separates the metallized electrode coating evaporated on the dielectric into a large number of small pieces with grid pattern gaps, and each small piece forms the electrode of a small unit capacitor. Each small unit has a tiny strip of coating that acts as a fuse, and connects to the surrounding small units across the isolation gap, and the current finally enters the conductive band that collects the current—the thickened side of the coating. If there is an electroweak point on the film of this structure, the breakdown discharge current will burn off the narrow strip of the outer plating layer of the small electrode block where the point is located...

AI Technical Summary

Problems solved by technology

[0004] However, the grid-type metallized safety film has a major defect: because there are tiny coating strips that act as fuses between each small block and adjacent small blocks around it, and most of the small blocks cannot be directly connected to the added film. The thick sides are adjacent to each other, and their current needs to pass through multiple other small blocks and narrow coating strips before reaching the thickened side; because the positions of the narrow coating strips of each small block from the thickened side are different, the superimposed current flowing through them is different , a large superimposed current flows through the tiny coating narrow strip closest to the thickened side that acts as a fuse. This superimposed current produces a large additional heat loss, which reduces the dielectric withstand voltage at the place, and even causes voltage breakdown

In order to reduce this heating loss, it is necessary to increase the width of the narrow strip of coating here, but considering the safety protection effect of the fuse, the width of the narrow strip of coating cannot be increased. This is a contradiction, and the design cannot be both

Therefore, because each small block of the grid-type metallized safety film does not have an independent tiny coating strip that acts as a fuse, current collusion and superposition between the small blocks often cause joint breakdown, and the reliability of safety protection is not as good as satisfactory

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