A capacitor film material with high adhesion to metal layer

Abstract

The invention discloses a capacitor film material with high adhesiveness with a metallic layer and belongs to the technical field of electronic components. The capacitor film material is specifically prepared from the following substances: modified diethyl polyterephthalate, polyimide, polytetrafluoroethylene, calcium carbonate, nano-silica, dibutyl phthalate, an antioxidant, a thermal stabilizer and an ultraviolet absorbent. According to the material disclosed by the invention, a film prepared from the material has good adhesiveness with a metallic zinc coating, a zinc-aluminum two-layer coating structural form can be adopted, and the existing metallic layer aluminum-zinc-aluminum triple-layer coating structure of a metallized film for capacitors is simplified, so that the increase of production efficiency is facilitated, and the production cost is reduced; during actual use, the film and the coating are in tight and stable adhered combination, the residual of internal air is reduced, then, the probability of air breakdown in a high-pressure state is lowered, and finally, the service life of each capacitor can be prolonged by 15% or more.

Description

technical field [0001] The invention belongs to the technical field of electronic components, and in particular relates to a capacitor film material with high adhesion to a metal layer. Background technique [0002] Film capacitors are widely used in analog circuits due to their excellent characteristics such as non-polarity, high insulation resistance, excellent frequency characteristics (broad frequency response), and low dielectric loss. A film capacitor uses a metal foil as an electrode, and it is laminated with a plastic base film such as polyethylene, polypropylene, polystyrene or polycarbonate from both ends, and then wound into a cylindrical structure called a capacitor. Due to the thicker metal foil, with the development of more and more refined electrical components, it is replaced by metal coating, that is, a layer of metal film is coated on the original film surface, which can significantly improve the size of components. . [0003] At present, the common metal...

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Problems solved by technology

That is, aluminum is plated on the film first. Although it is easily oxidized in the air to form a dense oxide layer with aluminum oxide as the main component, it can prevent the metallized film from being further oxidized, but when working under AC high voltage and high current, the The oxide layer will lead to a rapid decline in the capacity of the capacitor; for this reason, a layer of zinc on the basis of metallized film aluminum plating can well prevent the formation of an oxide layer on the inner layer of aluminum plating, so that the capacitor's capacity will not drop rapidly However, the metallized thin film galvanized layer has stronger reducibility and is oxidized faster in the air, and the zinc oxide formed by oxidation has a fluffy structure, which is difficult to prevent further oxidation. Therefore, the metallized thin film galvanized layer not only It is difficult to handle during processing, and it is easy to cause the capacitor to generate heat or even breakdown accidents; for this reason, it is necessary to coat a layer of aluminum on the basis of metallized film aluminum and galvanized, so as to protect the metallized film galvanized layer the role of

It can be found that the existing plating process is relatively complicated, and in order to improve the plating effect, it is usually necessary to carry out special surface treatment such as corona on the film, which undoubtedly increases the manufacturing cost. Even so, in actual use There are still two layers falling off, resulting in pores, and the problem of affecting the performance of the capacitor occurs