JPH10208973A - Manufacture of film capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a film capacitor which avoids depositing molten metal particles or makes the deposited metal particles easily removably when metal sprayed parts are formed at both ends of a film winding. SOLUTION: A metal deposition layer 13 on an outermost metallized film 11 is burned off to remove, winding the film and spraying a molten metal on both ends of the film winding 10 to be a capacitor element. A metal foil 14d for feeding a current to an electrode 14b of a burn-off apparatus is kept coated with a releasing agent 20 and wound by being transferred to a resin film at the deposited metal-free part A by the heating of the burn-off. The molten metal is sprayed on both ends of the winding 10 to form sprayed metal parts.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a film capacitor having a capacitor element formed by winding a metallized film formed by evaporating a metal on a resin film surface.

[0002]

2. Description of the Related Art Conventionally, this type of film capacitor has
As shown in FIG. 2, a general film on which no metal is vapor-deposited is formed on a protective film 12 on the outermost periphery of a film roll 10 on which a metallized film (metallized film) 11 formed by vapor-depositing metal on the surface of a resin film. As shown in FIG. 3, or as shown in FIG. 3, the evaporated metal layer 13 of the metalized film 11 at the end of the winding is electrically removed, and the portion A where the evaporated metal layer 13 is removed is used as the outermost protective film. Rolled up, glued and stopped by heat. As a method for electrically removing the vapor-deposited metal layer 13, a method called a burn-off method using a burn-off device 14 is usually employed.

[0003] The above-deposited metal layer 13 is removed and rolled up.
After bonding and stopping by heat, the element is thermoformed, and in the next step, molten metal particles are sprayed on both ends of the film winding body 10 to form a metal sprayed portion (generally called metallikon). In order to prevent the molten metal particles from adhering to other parts when spraying the molten metal particles, as shown in FIGS.
0 is masked using two masking tapes 15 and 16, and thereafter, molten metal particles are sprayed to form a metal spray portion.

[0004]

However, the above masking is not perfect, and when molten metal particles are sprayed to form a metal sprayed portion at both ends, the molten metal particles enter the gap 17 of the masking, and as shown in FIG. As shown, the molten metal particles 1
8 adheres and short-circuits the metal sprayed portions 19 formed at both ends of the film winding body 10 so that the insulation resistance and the dielectric loss tangent (ta) are reduced.
nδ). In particular, the temperature of the molten metal particles 18 for forming the metal spray portion 19 is high and the adhesion to the film is extremely large, so that it is extremely difficult to remove the molten metal particles 18 attached to the surface of the film roll 10. It is.

In order to prevent the adhesion of the molten metal particles, a method of applying a release agent such as wax or silicon to the outermost periphery of the wound capacitor element has been studied. If the thickness is not controlled very finely, there is a problem that the adhesion between the winding-stop films becomes poor, or the electrode wraps around the end surface (metal sprayed portion 19) from which the electrode is taken out, resulting in poor connection in electrical characteristics. For this reason, there has been a problem that the application of the release agent is technically difficult, and precise equipment is required to implement the release agent, resulting in an excessive cost.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and eliminates the above-mentioned problems. When a metallized film is wound and a capacitor element is manufactured, a vapor-deposited metal layer of the outermost metallized film is removed by burn-off. At the same time, a small amount of release agent is applied to the removed part to prevent the adhesion of molten metal particles when forming metal sprayed parts on both ends of the film roll, or even if it adheres, it is relatively easy An object of the present invention is to provide a method of manufacturing a film capacitor capable of removing molten metal particles.

[0007]

In order to solve the above problems, a metallized film formed by evaporating a metal on the surface of a resin film is wound, and the evaporated metal of the outermost wound metallized film is removed by a burn-off process. A film capacitor as a capacitor element is formed by winding a resin film of a portion from which the vapor-deposited metal has been removed as a protective film for the outermost periphery and spraying a molten metal on both ends of the metallized film roll to form a metal sprayed portion. In the manufacturing method, a release agent is previously coated on a metal foil used for an electrode in a burn-off step, and the release agent is transferred to a resin film of a portion from which a deposition metal has been removed by heat at the time of burn-off and wound, Thereafter, a molten metal is sprayed on both ends of the metalized film roll to form a metal sprayed portion.

[0008]

Embodiments of the present invention will be described below. FIG. 1 is a diagram illustrating a method for manufacturing a film capacitor according to the present invention. FIG. 3A is a diagram showing a state in which a metal deposition portion on the outermost periphery of a wound metallized film is removed by a burn-off process, and FIG. 3B is a partially enlarged view thereof.

In FIG. 1, a metallized film 11
Is a vapor-deposited metal layer (thickness of 100 to 150) obtained by vapor-depositing aluminum on the surface of PET (polyethylene terephthalate).
Å) 13 is formed. The metallized film 11 is wound to form a film roll 10. The vapor-deposited metal layer 13 of the final metallized film 11 is removed by burn-off using a burn-off device 14.
A small amount of the release agent 20 is added to the portion A where the metal deposition layer 13 is removed.
Is applied, and the part A to which the release agent 20 is applied is wound as a protective film for the outermost periphery, and is adhered and stopped by heat.

The burn-off device 14 includes a pair of electrodes 14b,
14c, metal foils 14d and 14e such as aluminum foil for supplying a current to the electrodes 14b and 14c, and a power supply 14a. The pair of electrodes 14b and 14c covered with the metal foils 14d and 14e are brought into contact with the metallized metal layer 13 of the metallized film 11, and a voltage is applied between the electrodes 14b and 14c via the metal foils 14d and 14e. 13 scatters. By moving the pair of electrodes 14b and 14c, the outermost wound metallized film 1 is moved.
In FIG. 1, a portion A from which the deposited metal layer 13 has been removed is formed.

A release agent 20 made of wax is previously applied to the surface of the metal foil 14d of the burn-off device 14 at a temperature of about 100.
Apply as thinly as possible at ℃. In this state, a pair of electrodes 14b, 14 covered with metal foils 14d, 14e
When c is brought into contact with the vapor-deposited metal layer 13 of the metallized film 11 and a voltage is applied between the electrodes 14b and 14c, the vapor-deposited metal layer 13 is scattered by burn-off as described above. At the same time, the heat generated at the time of burn-off
Is transferred to the portion A where the deposited metal layer 13 is removed.

As described above, the part A where the metallized film 13 of the outermost metallized film 11 is removed and the release agent 20 is transferred is wound as a protective film and adhered by heat.
Stop winding. Since the release agent 20 transferred here is very small, it does not affect the adhesive force by the heat seal for stopping the winding.

As described above, the deposited metal layer 13 of the outermost metallized film 11 is removed by the burn-off process, a small amount of the release agent 20 is transferred to the removed portion, wound, adhered and stopped by heat. The film winding body 10 having the configuration shown in FIG. 6 does not have to be subjected to the complicated masking in which the entire circumference is masked with a masking tape as in the related art.
The molten metal particles can be sprayed on both ends (for example, sprayed with molten solder) to form a metal sprayed portion by masking having a simple structure as shown in FIG. After forming the metal spray portion, the molten metal particles attached around the film winding body 10 are removed by a normal cleaning method.

As a result of performing a short-circuit check of the capacitor element manufactured as described above using a tester, all the capacitor elements were non-defective without short-circuit. Also, peeling due to poor sealing of the film winding does not occur. For comparative study, as in the conventional example, the outermost metallized film was wound by removing the vapor-deposited metal layer 13 by ordinary burn-off, and the same simple masking as described above was applied to the film wound body which was bonded and stopped by heat. After that, a metal sprayed portion sprayed with molten metal particles is formed, and thereafter, the capacitor element in which the molten metal particles adhered to the periphery of the film wound body are removed by a normal cleaning method, all of the short checks by the above tester are defective ( Short).

[0015]

As described above, according to the present invention, a metal foil used for an electrode in a burn-off step is coated with a release agent in advance, and the release agent is removed by heat at the time of burn-off. Transferred to the resin film of the part, and then wound a metallized film, since the molten metal is sprayed on both ends of the film wound body to form a metal sprayed part,
By simply applying a simple masking, it is possible to prevent the adhesion of the molten metal particles when forming the metal sprayed portion, or to remove the molten metal particles relatively easily even if they are attached. Therefore, the manufacturing method of the film capacitor becomes extremely easy.

[Brief description of the drawings]

FIG. 1 is a view for explaining a method of manufacturing a film capacitor according to the present invention. FIG. 1 (a) shows a state in which a metal deposition portion of a metallized film on the outermost periphery is removed by a burn-off step, and FIG. Is a partially enlarged view of FIG.

FIG. 2 is a diagram illustrating a conventional method for manufacturing a film capacitor.

3A and 3B are views for explaining a conventional method for manufacturing a film capacitor, in which FIG. 3A shows a state in which a metal deposition portion of a metallized film on the outermost periphery is removed by a burn-off step, and FIG. ) Is a partially enlarged view thereof.

FIGS. 4A and 4B are diagrams showing an example of masking in a conventional method for manufacturing a film capacitor. FIGS.

FIG. 5 is an external view of a capacitor element manufactured by a conventional film capacitor manufacturing method.

FIG. 6 is a diagram showing a simple masking example applied to a film roll.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Film roll 11 Metallized film 13 Metallized metal layer 14 Burn-off device 14a Power supply 14b, 14c Electrode 14d, 14e Metal foil 20 Release agent

Claims (1)

[Claims] 1. A metallized film formed by evaporating a metal on the surface of a resin film, and a metallized film of the outermost wound metallized film is removed by a burn-off process, and a portion of the resin film from which the evaporated metal is removed is removed. Is wound as a protective film for the outermost periphery, and a molten metal is sprayed on both ends of the metallized film wound body to form a metal sprayed portion to form a capacitor element. The metal foil to be coated is coated with a release agent in advance, and the release agent is transferred to a portion of the resin film from which the vapor-deposited metal has been removed and wound by heat at the time of burn-off. A method for manufacturing a film capacitor, characterized in that a molten metal is sprayed on both ends of the film to form a metal sprayed portion.