JP2007287829A - Metallized film capacitor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To further improve moisture resistance by a small number of processes by eliminating a metallized contact metal removing process. <P>SOLUTION: A metallized film is formed such that a metal evaporated electrode 3 is formed on a dielectric film 2. The metallized film is wound so that individual turns of the metal evaporated electrode 3 face each other via the dielectric film 2, and metallized contact electrodes 5 are formed on both end faces. Then, external terminals are so installed as to be exposed above the metallized contact electrodes 5 and provided at a capacitor element 1. The metallized film capacitor is formed by winding a plastic film 4 having a gas barrier property which is coated with a releasing agent around the capacitor element 1. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a metallized film capacitor in which a metallized film obtained by depositing metal on a dielectric film is wound.

  FIG. 9 is a side sectional view showing a conventional metallized film capacitor.

  In FIG. 9, a capacitor element 106 is wound with two metallized films deposited with metal deposited on one side of a dielectric film facing each other, and a winding film 108 using a polymer film is wound around the outermost periphery of the winding. It is a turn.

  A metallicon electrode 107 is formed on the winding end face of the capacitor element 106 as an electrode lead portion.

  In order to improve the moisture resistance, a metal barrier electrode 107 is formed by metal spraying after a gas barrier film or the like is wound around the outer periphery of the capacitor element 106 as a subsequent film 108 that is a barrier plastic film. It was. At this time, when the metallicon electrode 107 is formed, metal debris of the metallicon electrode 107 adheres to the side surface of the outer peripheral portion of the capacitor element 106, and therefore, an operation and a process for removing the adhered metal debris are necessary.

  After connecting the external terminal 109 to the metallicon electrode 107, it was wound with a plastic film 110 or the like, and both ends of the capacitor element 106 were covered with an insulating resin 111 or the like to constitute a metallized film capacitor.

As prior art document information related to the invention of this application, for example, Patent Document 1 and Patent Document 2 are known.
Japanese Patent Laid-Open No. 2002-8940 JP 2002-184642 A

  In the metallized film capacitor having the above-described conventional configuration, when the latter film 108 sprays the metallicon electrode 107, the metallicon metal adheres on the latter film 108, and the short circuit between the different electrodes due to the metallicon metal residue or the leakage current between the metallicon electrodes 107. Therefore, a work process for removing the metallicon metal was necessary because of the occurrence of defects due to the large size. An object of the present invention is to solve such a conventional problem and prevent the metallicon metal from adhering. Further, when the latter film 108 is wound around the capacitor element 106, when heat is applied to the capacitor element 106, the capacitor element 106 and the latter film 108 are caused by a difference in thermal shrinkage between the metallized film and the latter film 108. A gap or the like was formed between them, which had an adverse effect on moisture resistance.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to reduce the metallicon metal removal work process and further improve the moisture resistance with a small number of man-hours.

  Therefore, in order to achieve this object, the present invention is the same as a dielectric film in which a gas barrier plastic film with a release agent applied to the outer periphery of a capacitor element is wound, or a barrier plastic film is coated with a release agent. It is characterized by being sandwiched or pasted with a material.

  Since the metallized film capacitor of the present invention uses a barrier plastic film having a release agent applied to the outermost peripheral portion, work for removing excess metallicon metal on the outer peripheral portion of the capacitor element side surface adhering during metallicon metal spraying In addition, the moisture resistance can be improved. Further, since the moisture resistance of the capacitor element is improved, the epoxy resin and the case material, which are filling resins used for moisture-proof purposes, can be made thinner and lighter.

  In addition, the barrier plastic film is sandwiched between the same materials as the dielectric film, and by laminating, there is no sagging of the film due to differences in thermal shrinkage, and the effect of improving the moisture resistance without the looseness of the winding of the capacitor element is greater than before. Is.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment)
1 to 3 are configuration diagrams of a metallized film capacitor element according to an embodiment of the present invention.

  In FIG. 1, a capacitor element 1 includes two metallized films obtained by vapor-depositing a metal such as aluminum or zinc on one side of a dielectric film 2 such as polypropylene, and the metal vapor-deposited electrode 3 is a dielectric. It is wound so as to face each other through the film 2. In addition, when the metal vapor deposition electrode 3 was vapor-deposited on both surfaces of the dielectric film 2, what wound the metallized film and the dielectric film 2 may be used.

  As shown in FIG. 2, a gas barrier plastic film 4 coated with a release agent is wound around the outer periphery of the capacitor element 1. At this time, the release agent applied to the gas barrier plastic film 4 includes any of an alkyl pendant type, a silicon type, and a fluorine type. In the past, since no release agent was applied, the gas barrier plastic film 4 was likely to adhere metallicon metal such as zinc to the surface. However, alkyl pendant, silicon and fluorine compounds are zinc. Therefore, it is possible to prevent the metallicon metal from adhering to it by using it as a release agent. In addition, this mold release agent may be a fatty acid compound, and it makes it difficult for the metallicon metal to adhere by making the film surface smooth, and further prevents the adhesion of the metallicon metal by using a fatty acid compound. Also play.

  Next, as shown in FIG. 3, the metallicon electrode 5 is formed by spraying metallicon metal (not shown) from both end faces of the capacitor element 1 wound with the gas barrier plastic film 4. In addition, it winds so that the surface which apply | coated the mold release agent may become the outermost side of the capacitor | condenser element 1. FIG.

  At this time, a part of the metallicon metal which is the metallicon electrode 5 adheres so as to slightly wrap around the outer peripheral side surface from both end surfaces of the capacitor element 1.

  Thus, it is a technical feature in the present technology that the release agent is applied to the surface of the gas barrier plastic film 4 and wound around the outer peripheral portion of the capacitor element 1, whereby the metallicon electrodes provided at both ends of the capacitor element 1. In addition to the effect of preventing short circuit due to leakage between the metal electrodes, it is possible to reduce the removal work of excess metallicon metal on the outer peripheral side surface of the capacitor element 1 that adheres during metal spraying of the extraction electrode metallurgy and improve the moisture resistance. It has the effect of being able to do it.

  FIG. 4 is a perspective sectional view showing a barrier plastic film used in the embodiment of the present invention. The gas barrier plastic film 4 is intended for moisture resistance, and improves moisture resistance by providing an inorganic oxide layer coated with silicon oxide or silicon oxide and alumina on a resin film. As shown in FIG. 4, as a film obtained by applying a release agent to the gas barrier plastic film 4, a barrier layer 7 is applied on one side of the resin film 6 and a release agent 8 is applied and coated on the other side. Any resin film 6 may be used as long as it can deposit an inorganic oxide layer such as polypropylene, polyethylene terephthalate, polyethylene naphthalate, polyimide, and polyphenylene sulfite, and can add barrier properties by coating or the like. Capacitor element 1 using a polypropylene film When a resin film different from a dielectric film is used on the outer peripheral portion of the capacitor element, when heat is applied, a difference in heat shrinkage or a difference in film surface state causes loosening of the winding of the element or a subsequent film 9 Looseness is likely to occur. For example, polyethylene terephthalate and silicon oxide have excellent gas barrier properties. However, when the dielectric is a polypropylene film, the latter film 9 tends to loosen, which may adversely affect moisture resistance. Therefore, it is possible to increase the adhesion and improve the moisture resistance by laminating and sandwiching the gas barrier plastic film 4 with the same material as that of the dielectric film in which the release agent 8 is applied. In addition, as shown in FIG. 5, the barrier film may be formed by sandwiching the barrier layer 7 with a dielectric same material film 10 which is the same material as the dielectric film. In FIG. 2, the gas barrier plastic film 4 covers the entire outer periphery of the capacitor element 1, but it is preferable to provide a gap of at least 2.0 mm from the end face of the capacitor element 1. As a result, as shown in FIG. 3, the metallicon electrode 5 slightly wraps around and adheres to the portion having a distance of 2.0 mm or more, so that the outer peripheral portion of the capacitor element 1 is laid on the gas barrier plastic film 4. Metallicon metal can be prevented from adhering to the surface. Further, by separating the gap, the metallicon metal adhering to the portion adheres more strongly to the metallicon electrode 5, whereby the adhesive strength between the metallicon electrode 5 and the film can be increased.

  In addition, as a method of improving the barrier property of the gas barrier plastic film 4, the thickness of the gas barrier plastic film 4 may be increased, or a plurality of gas barrier plastic films 4 may be bonded together with an adhesive or the like. As a result, the moisture resistance is further improved.

  Furthermore, by making the gas barrier plastic film 4 a film having an inorganic oxide layer coated with silicon oxide or silicon oxide and alumina, the gas barrier plastic film 4 has better chemical resistance, acid resistance and oil resistance. It is possible to suppress oxygen permeability and water vapor permeability. The gas barrier plastic film 4 is wound around the outer periphery of the capacitor element 1 and is electrically drawn out from the metallicon electrode 5 with an external terminal or the like, housed in a case (not shown), and filled with a resin. The capacitor was completed. By doing so, it is possible to further prevent moisture and gas from entering the capacitor element 1 from the outside.

Example 1
As Example 1, a metallized film capacitor having the structure shown in the above embodiment was used. At this time, as the gas barrier plastic film 4, a 12 μm polyethylene terephthalate (PET) film obtained by vapor-depositing silicon oxide on one side was used, and the other side was coated with a silicon release agent.

(Example 2)
As Example 2, the same gas barrier plastic film 4 as the gas barrier plastic film 4 was obtained by depositing 4 sheets of silicon oxide deposited on a 12 μm PET film with a polyurethane-based adhesive and different from the silicon oxide deposited surface. What was bonded together with the polypropylene film which apply | coated the silicone type mold release agent on the other side was used.

(Example 3)
As Example 3, a gas barrier plastic film 4 in which silicon oxide was vapor-deposited on a 12 μm PET film and a polypropylene film coated with a silicon release agent was used as a gas barrier plastic film 4.

(Comparative Example 1)
As Comparative Example 1, the gas barrier plastic film 4 shown in each of the above examples was not used.

(Comparative Example 2)
As comparative example 2, it was set as the structure apply | coated to the post-wrapping film which has conventionally used the metallicon metal adhesion prevention release agent shown in the said Example.

  The results of performing a moisture resistance test on the metallized film capacitors of Examples 1 to 3 and Comparative Examples 1 and 2 thus configured are shown in FIG. 6, FIG. 7, and FIG.

  As test conditions, DC400V was loaded, and the capacity reduction rate at an ambient temperature of 85 ° C. and a humidity of 85% was measured.

  FIG. 6 shows Examples 1 and 2 and Comparative Example 1, and FIG. 7 shows Examples 1 and 3 and Comparative Example 1. In FIG. 6, the capacity reduction rate is suppressed by increasing the number of the gas barrier plastic films 4 to be bonded. This is because the moisture resistance of the capacitor is improved by the gas barrier plastic film 4. In FIG. 7, the capacity reduction rate is similarly suppressed by using the same material as the dielectric film 2 as the gas barrier plastic film 4. This is because the gas barrier plastic film 4 is the same as the dielectric film 2, so there is no difference in thermal shrinkage even when heat is applied to the capacitor element 1. As a result, the moisture resistance was improved and the capacity reduction rate was suppressed.

  FIG. 8 shows that in Example 1 and Comparative Example 2, the metallicon metal adhesion preventing release agent is applied to the gas barrier plastic film 4 to suppress the capacity reduction rate. When a metallicon metal adhesion preventing release agent is applied to a film other than the barrier plastic film, the capacity reduction increases because the release agent adversely affects oxidation and deterioration on the metallized film.

  Further, even if the metallicon metal removal work step was omitted by applying the release agent, there was no leakage on the outer peripheral side surface of the capacitor element between the metallicon electrodes 5.

  Further, according to the present embodiment, only the capacitor element 1 has been described. However, a lead-out terminal or the like is attached to the capacitor element 1, and the capacitor element 1 is accommodated in the case so as to be exposed from the resin case. The space between the element 1 and this case may be filled with resin.

  In this way, if the moisture resistance should be increased by increasing the thickness of the resin case and the resin to be filled, the thickness of the case and the filled resin can be reduced by 10 to 60% and light weight. It will be able to become.

  As described above, according to the metallized film capacitor according to the present invention, it is possible to greatly reduce the work process of removing the excess metallicon metal adhering to the outer peripheral side surface portion of the capacitor element, and to improve the moisture resistance by the barrier plastic film. Therefore, the present invention is useful for automobile systems that require high reliability in environments such as high temperature and high humidity.

Configuration diagram of metalized film capacitor according to Embodiment 1 of the present invention The perspective view of the metallized film capacitor by Embodiment 1 of this invention Metallicon electrode configuration diagram of metallized film capacitor according to Embodiment 1 of the present invention The perspective sectional view of the barrier film which applied the mold release agent by Embodiment 1 of the present invention Sectional drawing of composition of bonding of barrier film according to embodiment 1 of the present invention Graph of capacity reduction rate in moisture resistance test of Examples 1 and 2 and Comparative Example 1 Graph of capacity reduction rate in moisture resistance test of Examples 1 and 3 and Comparative Example 1 Graph of capacity reduction rate in moisture resistance test of Example 1 and Comparative Example 2 Sectional view of a conventional metallized film capacitor

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Capacitor element 2 Dielectric film 3 Metal vapor deposition electrode 4 Gas barrier plastic film 5 Metallicon electrode 6 Resin film 7 Barrier layer 8 Mold release agent 9 Back wound film 10 Dielectric material film 11 Capacitor element 12 Metallicon electrode 13 Back wound film 14 External terminal 15 Resin film 16 Insulating resin

Claims (7)

A metallized film having a metal vapor-deposited electrode formed on a dielectric film is wound so that the metal vapor-deposited electrode is opposed to the dielectric film, and metallized electrodes are formed on both end surfaces. A metallized film capacitor comprising a capacitor element having an external terminal attached so as to be taken out, and a gas barrier plastic film coated with a release agent on the outer periphery of the capacitor element. 2. The gas barrier plastic film having a release agent applied on the surface thereof is adhered and laminated, and the laminated gas barrier plastic film is wound around an outer periphery of the capacitor element. Metalized film capacitor. The metallized film capacitor according to claim 1, wherein the mold release agent includes any one of an alkyl pendant type, a silicon type, and a fluorine type compound. The metallized film capacitor according to claim 1, wherein the release agent is a fatty acid compound. 2. The metallized film capacitor according to claim 1, wherein the gas barrier plastic film is wound with a gap of 2.0 mm or more from each take-out electrode of the capacitor element. 2. The metallized film capacitor according to claim 1, wherein the gas barrier plastic film is a film having a layer coated with and coated with either silicon oxide or an alumina compound. The metallized film capacitor according to any one of claims 1 to 6, wherein the capacitor element is housed in a case and a space between the capacitor element and the case is filled with a resin.

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