JP2009206313A - Dry metal-evaporated film capacitor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dry metal-evaporated film capacitor which contrives the practical use of a capacitor element having polyvinylidene fluoride as a dielectric and allows further miniaturization than the capacitor element having polyvinylidene fluoride as a dielectric. <P>SOLUTION: A polyvinylidene fluoride resin film 1 mixed with a high-dielectric-constant filler having a metal-evaporated layer 2, e.g., a barium titanate powder, is wound. On the end surface thereof, metal is thermal-sprayed to form electrodes 3a and 3b, and external terminals 4a and 4b are connected and fixed to the electrodes 3a and 3b to form the capacitor element. The external terminals 4a and 4b are led out and coated with a metal laminate film 5 formed of a surface resin layer 5a, a metal layer 5b and an internal resin layer 5c to form a dry metal-evaporated film capacitor. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a dry metal vapor deposition film capacitor using a polyvinylidene fluoride resin film used as an electric device as a dielectric.

  A metal vapor deposition film in which a metal such as aluminum, zinc, or an alloy thereof is vapor-deposited is wound around the surface of a polymer film such as polypropylene or polyethylene terephthalate, and zinc, lead, tin, or an alloy thereof is thermally sprayed on both end surfaces thereof. The dry capacitor element formed by fixing the terminal to the electrode is used in, for example, a time constant circuit or an oscillation circuit of an electric device or the like.

By the way, in recent years, electric appliances and the like have been reduced in size. However, a capacitor using a polypropylene film (hereinafter referred to as PP film) or a polyethylene terephthalate film (hereinafter referred to as PET film) as a dielectric as described above. Then, there exists a problem that it cannot respond to size reduction of an electric equipment, since it cannot reduce in size with the same electrostatic capacitance and voltage.

In order to solve this problem, a polyvinylidene fluoride film having a relative dielectric constant several times larger than that of PP film (relative dielectric constant 2.2) or PET film (relative dielectric constant 3.2) is used instead of PP film or PET film ( It has been considered to use a dielectric constant of 10).
Japanese Examined Patent Publication No. 47-49661 Japanese Examined Patent Publication No. 46-37972

However, a capacitor element using a polyvinylidene fluoride resin as a dielectric can be reduced in size because of its large relative dielectric constant. However, even if the capacitor element is sealed in a can, it is molded with urethane rubber. However, there is a problem that the deterioration is so rapid that it cannot be put into practical use.

  The problem to be solved by the present invention is that a capacitor element using polyvinylidene fluoride as a dielectric can be put into practical use, and can be further reduced in size as compared with a capacitor element using polyvinylidene fluoride as a dielectric. It is to provide a capacitor.

  The present invention relates to a capacitor laminate formed by winding a metal-deposited polyvinylidene fluoride resin film and spraying metal onto its end face to form an electrode, and a metal laminate film formed of a surface resin layer, a metal layer, and an inner surface resin layer A dry metal vapor-deposited film capacitor that is packaged with a high dielectric constant filler mixed with the polyvinylidene fluoride resin.

  In the present invention, since a polyvinylidene fluoride resin film mixed with a high dielectric constant filler such as barium titanate is used as the dielectric of the capacitor element, the capacitor element can be made small, and the capacitor element can be formed with a surface resin layer. Since it is packaged with a metal laminate film formed of a metal layer and an inner surface resin layer, the capacitor element is completely sealed, thereby preventing a decrease in electrical breakdown strength over a long period of time, and a highly reliable dry metal vapor deposition film A capacitor can be obtained.

  A capacitor element using polyvinylidene fluoride as a dielectric material can be put into practical use, and the purpose of providing a dry metal vapor deposition film capacitor that can be further reduced in size compared to a capacitor element using polyvinylidene fluoride as a dielectric material A capacitor element is formed by winding a polyvinylidene fluoride resin film mixed with a high-dielectric-constant filler on which a layer is deposited, and the capacitor element is packaged with a metal laminate film formed of a surface resin layer, a metal layer, and an inner surface resin layer. It was realized by doing.

  FIG. 1 is a cross-sectional view showing a configuration of a metal vapor deposition film capacitor according to an embodiment of the present invention. In FIG. 1, 1 is a polyvinylidene fluoride resin film mixed with about 20% by volume of barium titanate powder, 2 is a deposited metal layer, 3a and 3b are electrodes, 4a and 4b are external terminals, and 5 is a metal laminate film. is there. The metal laminate film 5 includes a surface resin layer 5a, a metal layer 5b, and an inner surface resin layer 5c. Specifically, the surface resin layer 5a and the inner surface resin layer 5c form a plastic layer having a thickness of about 30 μm, and the metal layer 5b has a thickness. It is made of about 40 μm aluminum.

The polyvinylidene fluoride resin film mixed with barium titanate powder (relative dielectric constant 2000 or more) is obtained by mixing and stirring barium titanate powder having an average particle size of 0.3 μm or less when the polyvinylidene fluoride resin is heated and melted. Is formed into a film. The relationship between the mixing amount of the barium titanate powder and the relative dielectric constant ε is about 20 when the volume ratio is 20%, twice the relative dielectric constant 10 of the polyvinylidene fluoride resin, and 30% when the volume ratio is mixed. About 30, which is three times the relative dielectric constant 10 of the polyvinylidene fluoride resin.

The capacitor element is formed by stacking and winding a pair of polyvinylidene fluoride resin films mixed with barium titanate powder on which metal such as aluminum, zinc or an alloy thereof is deposited, and then pulling out the electrodes. The electrodes 3a and 3b are formed by thermal spraying a metal such as zinc, and the external terminals 4a and 4b are connected and fixed to the electrodes to form capacitor elements. Thereafter, the capacitor element is covered with the metal laminate film 5 with the external terminals 4a and 4b being led out, and the surrounding three sides are thermally welded and closed, and after the predetermined heat treatment, the remaining one side is thermally welded. The capacitor element is sealed with a metal laminate film 5.

As Example 1, a metal-deposited polyvinylidene fluoride resin film mixed with 12 μm-thick barium titanate powder was wound, and a capacitor element with a rating of 2000 V and 40 μF was packaged with a metal laminate film as described above. The volume at this time is 0.13 liter.

As Comparative Example 1, similarly to Example 1, a metal-deposited polyvinylidene fluoride resin film mixed with 12 μm-thick barium titanate powder was wound to form a capacitor element with a rating of 2000 V and 40 μF. A molded capacitor was formed. The volume at this time is 0.13 liter.

As Comparative Example 2, a 12 μm-thick metal-deposited polyvinylidene fluoride resin film was wound to form a capacitor element having a rating of 2000 V and 40 μF, and the capacitor element was formed by covering with a metal laminate film as described above. The volume at this time is 0.2 liter.

It can be seen that Example 1 and Comparative Example 1 are significantly smaller in volume than Comparative Example 2 and can be made compact. Therefore, for Example 1 and Comparative Example 1, long-term voltage application was performed at the rated voltage, and the element was taken out in the middle to measure the insulation strength. The result is shown in FIG. In FIG. 2, rhombuses indicate Example 1, circles indicate Comparative Example 1, the vertical axis indicates the rated voltage as 100, and the horizontal axis indicates the elapsed time. As is apparent from FIG. 2, in Example 1, the initial insulation strength was maintained even after 10000 hours, but in Comparative Example 1, the insulation strength suddenly decreased from around 80 hours.

Moreover, about Example 1 and the comparative example 1, long-term voltage application was performed with several types of voltages, and the voltage and time at the time of destruction were evaluated. The result is shown in FIG. In FIG. 3, rhombuses indicate Example 1, circles indicate Comparative Example 1, the vertical axis indicates the rated voltage as 100, and the horizontal axis indicates time. As is clear from FIG. 3, in Example 1, the capacitor element does not break down even after 10,000 hours have elapsed with an electric power of 125, that is, 2500 V, but in Comparative Example 1, the capacitor element breaks down even when the rated voltage of 2000 V is applied. To do.

That is, it can be seen from the above results that the capacitor according to the present invention is a highly reliable capacitor with stable electrical insulation characteristics over a long period of time.

It is sectional drawing which shows the structure of the dry-type metal vapor deposition film capacitor based on the Example of this invention. It is a characteristic view which shows the measurement result of the dielectric breakdown strength of a dry-type metal vapor deposition film capacitor | condenser element. It is an evaluation figure which shows the voltage and time at the time of destruction of a dry-type metal vapor deposition film capacitor | condenser element.

Explanation of symbols

1 Polyvinylidene fluoride resin film mixed with high dielectric constant filler 2 Deposition metal layers 3a and 3b are electrodes 4a and 4b External terminals 5 Metal laminate film

Claims (1)

A capacitor element formed by winding a metal-deposited polyvinylidene fluoride resin film and spraying metal on its end face to form an electrode is covered with a metal laminate film formed of a surface resin layer, a metal layer, and an inner surface resin layer. A dry metal vapor deposition film capacitor comprising a polyvinylidene fluoride resin mixed with a high dielectric constant filler.

Images