JPS581531B2 - capacitor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention involves wrapping a plastic film for first winding around a winding core several times and adhering it with a solvent, adhesive, heat sealing, etc. to form an integrated wound layered hollow body, and then The present invention relates to a method for manufacturing a capacitor in which a capacitor element is formed by winding a dielectric material and a metal foil, a metallized dielectric material, or a metalized dielectric material and a dielectric material.

Conventionally, when manufacturing a round metallized film capacitor, for example, metallicon metal such as solder or zinc was sprayed onto both end faces of the capacitor element in order to draw out the electrode lead wires in the process after winding the capacitor element. It's straining.

In general, round-shaped capacitor elements have hollow core trace holes, so during metallization, metallicon metal enters the core trace hole of the capacitor element, which adversely affects electrical properties such as insulation resistance and dielectric loss tangent of the capacitor. .

In order to prevent this problem, it is necessary to plug the winding core hole of the capacitor element, or to prevent metallization metal from entering by providing an appropriate shield when using metallicon, or to use insulating color or plastic film called first winding. The wire is wound several times to reduce the effect of metallic intrusion.

Furthermore, the above-mentioned round metallized film capacitors and round film capacitors in which a plastic film and metal foil are wound have unstable electrical characteristics due to thermal contraction of the plastic film.

As is well known, since plastic films are manufactured by a stretching method, the molecules are oriented in a certain direction, and therefore thermal contraction occurs in the high temperature region as shown in FIG. 1, depending on the characteristics of the plastic film.

In Figure 1, PP is polypropylene film, PS
is polystyrene film, and PET is polyethylene terephthalate film.

Therefore, when a wound capacitor element is heat-treated (this is done to stabilize the electrical characteristics of a plastic film capacitor), stress concentrates on the winding core due to thermal contraction of the plastic film, as shown in Figure 2. The winding core may collapse or cavities may form between the plastic films near the winding core, making it difficult to maintain the set capacitance, and in the case of metallized film capacitors, metallicon metal may enter the cavities between the plastic films during manufacture. Not good.

For capacitors that require high precision capacitance or low dielectric loss tangent by using polypropylene or polystyrene film, which have a particularly high thermal shrinkage rate, a glass core or plastic molded rod may be inserted into the hollow part of the winding core, or a molded plastic rod may be preformed. Generally, a method was adopted in which a plastic film was directly wound around a glass or plastic core.

In addition, capacitors with laminated winding of metallized film and capacitor paper, capacitors with laminated winding of metallized paper and plastic film, and capacitors with laminated winding of plastic film, capacitor paper, and metal foil are also capacitors in the same way as in the above case. This is undesirable because metallicon metal enters the winding core trace hole of the element and heat shrinkage of the plastic film causes the winding core to collapse or a cavity to form between the plastic film and the capacitor paper.

Furthermore, metallized paper capacitors made of metallized paper or metallized paper and capacitor paper wound in a laminated manner, and capacitors made of laminated and wound capacitor paper and metal foil, may have metallic condensate metal entering the winding core hole of the capacitor element and adhering to it. Also, there is a drawback that the capacitor may be deformed during transportation before being housed in a capacitor container.

The present invention seeks to provide a method for manufacturing a capacitor that eliminates the above-mentioned drawbacks.

Hereinafter, a method for manufacturing a capacitor according to the present invention will be explained with reference to FIG.

In the process of winding the first winding plastic film 2 such as polycarbonate film or polyester film around the winding core 1 to a thickness of about 0.5 to lim, the first winding plastic film 2 is first wound around the winding core 1 2 to 5 times. Then, a device 4 (this device moves reciprocatingly) equipped with a container containing a solvent or adhesive, an applicator, a heat source heater, etc. approaches the winding core 1, and then the plastic film for pre-winding is placed on the winding core 1. 2 is wound, a solvent or adhesive is applied to the first-wound plastic film 2, or the first-wound plastic film 2 is heat-sealed by heating with a heat source heater to seal the first-wound plastic film 2 between each other. Glue.

When the device 4 is wound around the winding core 1 a required number of times, the device 4 moves away from the winding core 1.

After that, add 2 to 2 plastic films for first winding.
Wrap it 5 times.

In this way, the layers of the first winding plastic film 20 are completely bonded and integrated to form the wound layered hollow body 3.

This wound layered hollow body 3 exhibits the same effect as a plastic molded rod inserted into the winding core trace, and its strength is significantly greater than that of one that is not integrated (one that is simply wrapped with a plastic film for first winding).

A dielectric material (capacitor paper or plastic film) and a metal foil, or a metalized dielectric material (metalized paper or metalized film), or a metalized dielectric material (metalized paper or metalized film) is placed on the wound layered hollow body 3. ) and a dielectric (capacitor paper or plastic film) are wound to form a capacitor element.

Then, the capacitor element is extracted from the winding core 1 together with the wound layered hollow body 3.

Since the capacitor element formed in this way has a wound layered hollow body 3 made of the plastic film 2 for first winding inside, when metallicon metal is sprayed on both end faces of the capacitor element, the winding core trace hole of the capacitor element Even if metallic metal enters into the capacitor, it is difficult to adhere to the capacitor, so the electrical properties such as insulation resistance and dielectric loss tangent are good.Also, since the wound layered hollow body 3 has high strength, the plastic film near the center of the capacitor element Excellent effects such as no formation of cavities or deformation of the capacitor element due to mechanical impact can be obtained.

Next, examples of the present invention will be shown.

Example 1 Fujitac film (manufactured by Fuji Photo Industries) having a thickness of 20 μm was wound around a winding core as a pre-winding plastic film.

From the third to the 45th time, acetone is applied as a solvent, and the material is wound around the core 50 times to form a wound layered hollow body.

Thereafter, a metallized polypropylene film is wound onto the wound layered hollow body to form a capacitor element.

The capacitor obtained by this manufacturing method has a strong wound layered hollow body, and the capacitor element does not have cavities or deformation due to heat treatment, transportation, etc., and the wound layered hollow body is made of metal. It has good electrical properties because it is difficult to adhere to it.

Example 2 A polycarbonate film (manufactured by Bayer) having a thickness of 25 μm was wound around a winding core as a plastic film for first winding.

From the third to the 35th time, acetone is applied as a solvent and the material is wound 40 times around the core to form a wound layered hollow body.

Thereafter, a metallized polypropylene film is wound onto the wound layered hollow body to form a capacitor element.

The capacitor obtained by this manufacturing method is Example 1.
had a similar effect.

Example 3 A 25 μm thick polyester film (Lumirorashi trademark, manufactured by Toray Industries, Inc.) was wound around a winding core as a first-winding plastic film.

Then, from the third to the 35th time, heat welding is performed using a heat source heater at a temperature of 230 to 240° C., and the material is wound around the core 40 times to form a wound layered hollow body.

Thereafter, a metallized polypropylene film is wound onto the wound layered hollow body to form a capacitor element.

The capacitor obtained by this manufacturing method is Example 1.
had a similar effect.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the thermal shrinkage rate-temperature characteristic of a plastic film, Fig. 2 is a plan view of a conventional round capacitor element, and Fig. 3 is a diagram showing the formation of a wound layered hollow body in the manufacturing process of the capacitor of the present invention. A is a schematic plan view, and the mouth is a schematic side view. PP: polypropylene film, PS: polystyrene film, PET: polyethylene terephthalate film, 1: core, 2: plastic film for first winding, 3:
20 rolls of plastic film for first winding A rolled layered hollow body made by bonding and integrating the layers, 4: Solvent, adhesive, applicator,
A device equipped with a heat source heater, etc.

Claims (1)

[Claims] 1. Wrap a plastic film for first winding around the winding core several times and adhere with solvent, adhesive, heat sealing, etc. to form an integrated wound layered hollow body, and in this wound layered hollow body, dielectric material, metal foil, Or a method for manufacturing a capacitor, which comprises forming a capacitor element by winding a metallized dielectric or a metallized dielectric and a dielectric.