Metallized film capacitor and metal layer spraying and heat treatment method thereof

Abstract

The invention relates to a metallized film capacitor and a metal layer spraying and heat treatment method thereof, the metallized film capacitor comprises a capacitor core, and the metallized film capacitor is characterized in that the capacitor core is of a round core type or a flat core type and is formed by winding at least one polypropylene film, and a plurality of metal layers are respectively sprayed at the upper end and the lower end of the capacitor core after the capacitor core is wound; wherein a plurality of evaporation aluminum layers are distributed on the surface of the polypropylene film, metal thickening layers are arranged on the evaporation aluminum layers, and reserved edges are arranged between the adjacent evaporation aluminum layers. And a plurality of different materials are adopted to spray the plurality of metal layers, so that the end face over-current capability and the heat dissipation capability of the capacitor product are effectively improved. Through cooperation of heat treatment and a hot pressing clamp, it can be effectively guaranteed that the temperature difference inside and outside the capacitor core is small, it is guaranteed that internal tension of the wound capacitor core is fully released, uniformity of internal tension of a polypropylene film is guaranteed, the application range is wide, and practicability is high.

Description

technical field [0001] The invention relates to a capacitor, in particular to a metallized film capacitor and its metal layer spraying and heat treatment methods. Background technique [0002] At present, the traditional metallized film capacitors are directly sprayed with two materials of pure zinc or zinc-tin alloy after winding to form an integral electrode surface, and then welded. In the prior art, limited by the welding process, zinc and tin-zinc alloys are mostly used as the terminal electrode material of capacitors, but zinc and zinc-tin alloys have the disadvantages of high resistivity and low thermal conductivity, and the resistivities of zinc and tin are respectively 59nΩ .m and 11.4nΩ.m, the thermal conductivity of zinc and tin are 112W / mk and 64W / mk respectively; Trapped by the trap bands, the trap charges are formed, which leads to the destruction of the material structure, which limits the service life of the capacitor and the development of higher currents o...

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Problems solved by technology

However, the heat treatment in the atmospheric oven is affected by the heat treatment fixture and the heat treatment process. It is difficult to squeeze out 100% of the water vapor and air remaining in the film after winding, and because the air and water vapor cannot be completely eliminated, the current domestic film resistance The pressure level cannot be raised to the limit of the film; the power used for heat treatment in an empty oven is relatively large, the ambient noise is relatively large, and the working environment is difficult to use. At the same time, the temperature rise is relatively slow, and because the vacuum space is relatively large, the internal temperature cannot be uniform. As a result, the product is heated unevenly inside the oven, and the air and water vapor between the film layers cannot be uniformly removed, resulting in poor heat treatment consistency of the capacitor core.

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