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JP-2026076009-A - Capacitor and method for manufacturing the same

JP2026076009AJP 2026076009 AJP2026076009 AJP 2026076009AJP-2026076009-A

Abstract

[Problem] To provide a capacitor with low loss and excellent long-term durability at high temperatures, and a method for manufacturing the same. [Solution] The capacitor has a structure in which metallized films, each having metal layers B1, B2, C1, C2, D1, and D2 on both sides of a resin film, are adjacent to each other. This is equivalent to doubling the thickness of the electrode metal layer, thus achieving low resistance, which in practical terms suppresses heat generation and makes short-circuit failures less likely. [Selection Diagram] Figure 3

Inventors

  • 藤城 義和

Assignees

  • 王子ホールディングス株式会社

Dates

Publication Date
20260511
Application Date
20241023

Claims (11)

  1. A capacitor characterized by having adjacent metallized films, each having a metal layer on both sides of a resin film.
  2. The capacitor according to claim 1, comprising winding or laminating the aforementioned metallized film.
  3. The capacitor according to claim 1, wherein the void ratio in the thickness direction is 0.5% or more and 5% or less.
  4. The capacitor according to claim 1, wherein the film resistance of the metal layer is 5 to 25 Ω/□.
  5. The capacitor according to claim 1, wherein the metal layer is formed by vapor deposition.
  6. The capacitor according to claim 1, wherein the adjacent metal layers are drawn out to the same end face of the capacitor.
  7. A method for manufacturing a capacitor, A manufacturing method characterized by comprising step 1 of winding or laminating a metallized film having metal layers on both sides of a resin film.
  8. The manufacturing method according to claim 7, wherein the capacitor has a void ratio in the thickness direction of 0.5% or more and 5% or less.
  9. The manufacturing method according to claim 7, wherein the film resistance of the metal layer is 5 to 25 Ω/□.
  10. The manufacturing method according to claim 7, further comprising a metal deposition step of forming a metal layer on both sides of the resin film by vapor deposition, prior to step 1.
  11. The manufacturing method according to claim 7, further comprising step 2 of forming a pair of metallicon electrodes on both end faces of the capacitor after step 1.

Description

This invention relates to a capacitor and a method for manufacturing the same. Conventionally, capacitors such as film capacitors have been used in electronic and electrical equipment. Examples of such capacitors include high-voltage capacitors, filter capacitors for converters and inverters, and smoothing capacitors. Power conversion devices such as converters and inverters, as described above, require improved power conversion efficiency, and power transmission and distribution networks require improved transmission and distribution efficiency. In particular, since power is converted into heat due to power loss, capacitors must have low losses. The capacitors mentioned above may be used at high temperatures depending on the application. Furthermore, with the increasing performance of electronic and electrical equipment in recent years, capacitors are subjected to loads, and self-heating can cause them to become hot. Therefore, there is a demand for capacitors that can be used at high temperatures. As a capacitor for use at high temperatures, a capacitor has been proposed in which a metallized film, having a metal layer on one side, is laminated onto a resin film such as a polypropylene film and then wound up (see, for example, Patent Document 1). Japanese Patent Publication No. 2018-125547 This is a schematic diagram illustrating the capacitor of the present invention.This is a schematic diagram showing the cross-section parallel to both end faces and the thickness of the capacitor of the present invention.This is a schematic diagram showing a portion of the cross-section perpendicular to both end faces of the capacitor of the present invention.This is a schematic diagram showing a conventional capacitor with stacked metallized films.This is a schematic diagram showing a conventional capacitor with stacked metallized films. In this specification, the expression "consisting of" includes the concepts of "substantially consisting of" and "consisting of only." In this specification, the term "capacitor" includes the concepts of "capacitor," "capacitor element," and "film capacitor." 1. Capacitor The capacitor of the present invention is a capacitor having a structure in which metallized films, each having a metal layer on both sides of a resin film, are adjacent to each other. The capacitor of the present invention having the above features uses a metallized film having a metal layer on both sides of a resin film, and because the metallized films are adjacent to each other, the metal layers of the metallized films are adjacent with only a small gap between them. As a result, the thickness of the metal layer is equivalently doubled, the ESR (equivalent series resistance) can be reduced, and the loss is reduced. Therefore, power loss in the circuit is suppressed, and the power transmission and distribution efficiency and conversion efficiency are improved. Furthermore, even when voltage is loaded onto the capacitor of the present invention at high temperatures, unlike the case of a single thick metal layer, the presence of an air gap between the two metal layers makes it easier for the electrodes to evaporate, thus providing self-healing properties, suppressing dielectric breakdown, and providing excellent long-term durability at high temperatures. Furthermore, in the capacitor of the present invention, since there is almost no air gap between the metal layers (between electrodes) sandwiched between the resin film, the capacitance is increased. As a result, a capacitor of the same volume can have a larger capacitance, and a capacitor of the same capacitance can be made smaller. The capacitor of the present invention is a capacitor having a structure in which metallized films, each having a metal layer on both sides of a resin film, are adjacent to each other. The capacitor of the present invention only needs to have a structure in which the metallized films are adjacent to each other, as long as it is manufactured using a metallized film having a metal layer on both sides of a resin film. It may also include, to a small extent, capacitors that include a metallized film with a metal layer on one side of the resin film, or a resin film without a metal layer. In other words, the capacitor of the present invention may be substantially composed of a metallized film having a metal layer on both sides of a resin film. From the viewpoint of achieving lower losses and improved long-term durability at high temperatures, it is preferable that the capacitor of the present invention consists only of a metallized film having a metal layer on both sides of a resin film (without including a metallized film with a metal layer on one side of the resin film, or a resin film without a metal layer). The structure of the capacitor of the present invention will be explained with reference to the figures. Figure 1 is a schematic diagram showing the capacitor of the present invention. In Figure 1, the capacitor 10 of the present invent