Method for preparing thin film capacitor

Abstract

The invention relates to a method for preparing a thin film capacitor. The method includes winding, cold pressing, hot pressing, hot baking, metal spraying and subsequent processes, the preparation method and steps thereof sequentially are: (1) winding: superposing a metalized polypropylene thin film and winding to form a core; (1) cold pressing: flattening the core; (3) pretreatment: placing thecore after cold pressing in a sealed space, adjusting the temperature to 40 DEG C+ / -5 DEG C, adjusting the humidity to RH35% or below, and adjusting placing time to 2 to 10 hours; (3) hot pressing: performing preliminary sizing on the pretreated core; (4) metal spraying: performing metal spraying coating on an end face of the core after hot pressing, the metal spraying coating being in contact with a metal coating on the metalized polypropylene thin film and being let out; (5) hot baking: putting the core after metal spraying in a drying oven to realize sizing; and (6) subsequent processes. The method for preparing the thin film capacitor effectively eliminate various stress generated on the thin film, deformation is not easy to occur, the end face of the core can be guaranteed to be effectively led out, a metal spraying layer is not easy to deform, and hum of the capacitor is obviously reduced.

Description

technical field [0001] The embodiments of the present invention relate to a method for preparing a capacitor, in particular to a method for preparing a film capacitor. Background technique [0002] In the prior art, there are following defects in the production process of film capacitors: [0003] 1. There is no pretreatment process. After the film is wound, there is no tension stress relief process, and it is directly heat-treated. In this way, the film is greatly affected by tension and stretching, and it is difficult to effectively recover the small damage between the films. [0004] 1. The current process sequence of motor capacitors basically adopts the sequence of heat treatment first, and then gold spraying. The defect is that there are still gaps between the films, and the humming sound after the motor is installed is relatively large. [0005] , The current products, post-processing, especially the potting and curing process, will be heat-treated at a certain tempe...

AI Technical Summary

Problems solved by technology

[0005] , The current products, post-processing, especially the potting and curing process, will be heat-treated at a certain temperature, such as 60 ℃, 85 ℃, 115 ℃ and other temperature conditions for heat-baking treatment to ensure the curing performance, but this heat treatment The process will cause a second setting of the capacitor core that has been shaped in the early stage. In fact, this second setting will cause a certain gap in the core that has no air gap. At the same time, due to the curing condition of a certain temperature , the cured epoxy resin will increase its fluidity at a higher temperature, and then enter the gap of the core, forming a certain destructive effect on the core, resulting in the adverse effect of increased hum