Heat dispersion structure and method of thin film capacitor

Abstract

The invention discloses a heat dispersion structure and method of a thin film capacitor. The thin film capacitor comprises a thin film core and positive and negative bus-bars connected with an end face of the thin film core, wherein the thin film core and the bus-bars are arranged in a closed plastic shell; the bus-bars extend along a contact bottom surface of the plastic shell and a cooling plate respectively to form an epitaxial part; and the epitaxial part contacts the cooling plate; or the thin film core and the bus-bars are arranged in a plastic shell with an open bottom; the bus-bars contact the cooling plate directly or by the extended epitaxial part; and insulation paper is arranged between the contacted bus-bars and the cooling plate. On the basis of keeping the original size of the thin film capacitor, the internal bus-bars are extended, thus the bus-bars contact the cooling plat for the purpose of heat dispersion through the insulation paper, thereby greatly reducing the heat resistance of the thin film capacitor, solving the heat dispersion problem of the thin film capacitor completely, and prolonging the service life of the thin film capacitor.

Description

technical field [0001] The invention relates to a film capacitor, in particular to a heat dissipation structure of a film capacitor. Background technique [0002] Film capacitor is a kind of capacitor with good performance. It has the characteristics of small parasitic parameters, good temperature frequency response characteristics, safety and reliability, and is gradually replacing traditional electrolytic capacitors. It is currently widely used in the automotive field, especially in electric vehicles and in hybrid cars. [0003] The film core 1 of the film capacitor has the dissimilarity of heat conduction, and the thermal conductivity of the film itself is not good, but a layer of metal coating 12 evaporated on the film 11 has good thermal conductivity, so the heat is easier to flow along the coil. Conducted in the axial direction of the winding, that is, the thermal resistance of the film core in the axial direction is much smaller than that in the radial direction, suc...

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Problems solved by technology

Especially in hybrid applications, the environment can reach a high temperature of 105°C, and the polypropylene film inside the capacitor can withstand a hot spot temperature of 105°C, so the capacitor cannot bear the heat caused by any current at this time.

Even if the ambient temperature is below 85°C, the internal core temperature will be close to 105°C for a long time when working at full capacity, which will shorten the life of the capacitor

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