JPH11186090A - Capacitor and metallized dielectric for the capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the increase of tan δ of the dielectric of a capacitor due to humidity in air, etc., by laminating metallic layers on a dielectric, and by providing this metallic layer with a metallized dielectric wherein the metallic layers are covered with a protective layer, made of a fluorine-based substance and having its thickness not smaller than a specific value. SOLUTION: A film form dielectric 2 is made of a macromolecular film or a capacitor paper. Laminating such a thin foundation metal layer such as copper on the surface of the dielectric 2, a metallic layer 3 made of a metal as zinc and aluminum is laminated on the surface thereof. Still, a longitudinal one-end portion of the dielectric 2 is brought into the state of the metallic layer 3 being not laminated on it to use it as a non-metallic portion 4. Then, on the surfaces of the metallic layer 3 and the non-metallic portion 4, there is laminated a protective layer 5 made of a fluorine-based substance and having its thickness not smaller than 1 Å. Still, the protective layer 5 must be laminated at least on the surface of the metallic layer 3 although its lamination on the non-metallic portion 4 is not necessarily required.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a capacitor using a metallized film or metallized paper and a metallized dielectric for the capacitor.

[0002]

2. Description of the Related Art Metallized film capacitors and metallized paper capacitors are made of a metal such as zinc or aluminum on the surface of a film-like dielectric such as a polymer film such as a polyester film or a polypropylene film or a capacitor paper. A metallized dielectric having a structure in which thin films are stacked is used. The film-shaped metallized dielectric is wound to form a capacitor element. Further, a metallikon layer made of a sprayed metal such as zinc or copper is formed on an end face of the capacitor element. Terminals are connected to the metallikon layer by soldering, electric welding, or the like. Furthermore, storing the capacitor element in a resin case or metal case,
It is covered with a resin exterior formed by a resin dipping method or a resin molding method. In particular, a metallized film or the like in which a metal layer made of zinc is stacked has a characteristic that the rate of change in capacitance is smaller than that in a case where a metal layer made of aluminum is stacked.

When a metallized film or metallized paper is left in the air, the metal layer is oxidized due to moisture in the air, the electrical conductivity of the metal layer is reduced, and tan δ is increased. This tendency is larger in the metal layer made of zinc than in aluminum.

Conventionally, in order to prevent the increase in tan δ due to moisture in the air, when a metallized film is used, heat treatment is performed at a temperature of 30 ° C. to 70 ° C. for about 24 to 48 hours (hour). I have.

[0005]

However, when the humidity in the air exceeds 60% RH, the conventional heat treatment alone
The effect of preventing an increase in tan δ of a metalized film or the like is reduced, and there is a disadvantage that tan δ tends to increase.

An object of the present invention is to provide a capacitor and a metallized dielectric for a capacitor which can improve the above disadvantages, prevent an increase in tan δ due to moisture in the air, etc., and improve the life.

[0007]

According to the first aspect of the present invention, there is provided a capacitor having a capacitor element made of a metallized dielectric, in which a metal layer is laminated on the dielectric and the metal layer is formed. A capacitor is provided which comprises a metallized dielectric layer coated with a protective layer comprising a fluorine-based material and having a thickness greater than 1 Å.

According to a second aspect of the present invention, there is provided a metallized dielectric for a capacitor in which a metal layer is laminated on a dielectric, the protective layer comprising a fluorine-based material covering the metal layer and having a thickness of more than 1 Å. A metallized dielectric for a capacitor is provided.

That is, fluorine-based substances such as fluorine-based oils and fluorine-based resins have the property of being hardly soluble in water and acids. Therefore, by covering the metal layer made of zinc or the like with a protective layer made of a fluorine-based material and having a thickness of more than 1 Å, it is possible to prevent the metal layer from being oxidized by moisture in the air or the like for a long time. And capacitors
The increase in tan δ can be reduced.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a perspective view of the metallized dielectric 1. That is, 2 is a film-shaped dielectric,
It consists of polymer film and capacitor paper. As the polymer film, a polyester film or a polypropylene film having a thickness of about several μm to several tens of μm, a polyethylene film, a polyimide film, a polycarbonate film, a polystyrene film, a polytetrafluoroethylene film, a polytetrafluoroethylene film, a polyphenylene sulfide film, A polyvinylidene fluoride film or the like is used. Further, the capacitor paper may have a thickness of about several μm, and may be one coated with an insulating lacquer on one side to a thickness of several μm.

On the surface of the dielectric 2, a thin underlying metal layer (not shown) such as copper is laminated, and the surface is made of a metal such as zinc or aluminum and has a resistance of about 1 to 5 Ω / □. The metal layer 3 is laminated. Note that one end in the longitudinal direction of the dielectric 2 is in a state where the metal layer 3 is not laminated as the non-metal portion 4.

On the surfaces of the metal layer 3 and the non-metal portion 4, a protective layer 5 made of a fluorine-based substance and having a thickness of more than 1 Å is laminated, and covers the metal layer 2. Note that the protective layer 5 only needs to be at least on the surface of the metal layer 3 and does not have to be laminated on the non-metallic part 4. As the fluorine-based substance, for example, a fluorine-based oil or a fluorine-based resin is used. As the fluorinated oil, a vacuum pump oil or the like is used. As the fluorine-based resin, a synthetic resin made of a copolymer such as polytetrafluoroethylene, polychlorotrifluoroethylene, vinyl fluoride, ethylene trifluoride, vinylidene fluoride, and propylene hexafluoride is used. The thickness of the protective layer 5 is 1
It is thicker than Å, preferably about 3 to 700 Å. The thickness of the protective layer 5 is 1
When the thickness is less than Å, there is almost no effect of improving the moisture resistance. Further, the protective layer 5 may not be directly provided on the metal layer 3, and another layer may be interposed between the metal layer 3 and the protective layer 5. That is, the protective layer 5 may cover the metal layer 3 via another layer, and similarly, the moisture resistance and the like are improved by the properties of the fluorine-based oil or the fluorine-based resin forming the protection layer 5. The effect is obtained.

FIG. 2 shows a capacitor 7 having a capacitor element 6 formed by winding the metallized dielectric 2.
FIG. The capacitor element 6 is formed by laminating and winding two metallized dielectrics 1 with the non-metallic parts 4 being reversed with respect to each other, or a film-like dielectric in which the metal layer 3 is not formed between the metallized dielectrics 2. The thing which interposed was wound. This capacitor element 6 may be of a stacked type.

On the end face 8 of the capacitor element 6, a metallikon layer 9 made of a sprayed metal such as zinc, lead, copper, tin or the like is provided.
Are laminated. Metallicon layer 9 has lead-like terminals 1
0 is connected by soldering, electric welding, or the like. Further, the capacitor element 6 is covered with a resin exterior 11 with the end of the terminal 10 pulled out. In addition,
Instead of covering with the exterior 11, the capacitor element 6 may be housed in a case such as a resin case or a metal case.

Next, a manufacturing method according to an embodiment of the present invention will be described. First, a petroleum-based oil is applied to a portion of the surface of the dielectric 2 such as a polymer film which is to be the non-metallic portion 4. Next, using a vacuum deposition, an ion plating device, a sputtering device, or the like, a thin copper film is deposited on the surface of the dielectric 2, and a metal such as zinc or aluminum is deposited on the surface and oil is applied. The metal layer 3 is formed at a location other than the metal part 4. After the formation of the metal layer 3, a fluorine-based substance such as a fluorine-based oil or a fluorine-based resin is directly deposited on the surfaces of the metal layer 3 and the non-metallic part 4 by using the same or different vacuum deposition apparatus or the like. The protective layer 5 having a thickness of more than 1 Å is formed. When a vacuum deposition apparatus is used, the degree of vacuum in the apparatus is set to 50 × 10 ⁻³ Torr or less,
By setting the heating temperature of the fluorine-based material to about 120 ° C. to 200 ° C., it is easy to form a uniform protective layer 5. Thereafter, if necessary, in the case of a metallized film, heat treatment is performed at a temperature of 30 to 70 ° C. for 24 to 48 hours.

After the heat treatment, the metallized dielectric 1 is wound up by a predetermined length by an automatic winding machine to form a capacitor element 6. Then, the capacitor element 6 after winding the metallized dielectric 1 is heated at a temperature of, for example, about 100 ° C. to 150 ° C.
Heat treatment for about 2 hours. By performing this process, when a metallized film is used, the metallized film can be shrunk to stabilize the capacitance and the like. After heating the capacitor element 6, the capacitor element 6
A spray metal such as zinc or copper is sprayed on the end face 8 to form a metallikon layer 9. At this time, the side surface is masked with a paper adhesive tape or the like so that metal does not adhere to the side surface of the capacitor element 6. After the metallikon layer 9 is formed, the terminals 10 are connected to the metallikon layer 9 by soldering, electric welding, or the like. After the terminals 10 are connected, an exterior 11 made of resin or the like is formed by a resin dipping method, a resin molding method, or the like. After the exterior 11 is formed, a voltage process is performed, and the metal layer 3 around the weak point portion of the dielectric such as a polymer film or capacitor paper is predicted in advance.
Is removed. Through the above steps, the capacitor 7 is manufactured.

[0017]

Next, an embodiment of the present invention will be described. The dielectric material is 600mm wide, 3500m long and 7μ thick
m of polypropylene film. Then, on the surface of the polypropylene film, a metal layer made of zinc having a purity of 99.99% and having a resistance value of 4Ω / □ is laminated. Also,
The surface of the metal layer is made of Demnum-S20 (fluorine oil, trade name of Daikin Industries, Ltd.) with a thickness of 3 to 8
A protective layer of 00 Å is laminated. This protective layer is formed by using a vacuum evaporation apparatus and having a degree of vacuum of 50 × 10 ⁻³ Torr.
Hereinafter, Demnum-S20 is formed by heating at a temperature of 120 ° C to 200 ° C and performing vacuum deposition.

Then, a change in the resistance value of the metal layer when the above-described example is left in an atmosphere of a temperature of 65 ° C. and a humidity of 90% RH is measured together with the comparative example and the conventional example.

The comparative example was manufactured under the same conditions except that the thickness of the protective layer was 1 angstrom in the example. The conventional example is manufactured under the same conditions except that the heat treatment time is set as shown in Table 1 without forming the protective layer in the example. Then, the sample is left in a roll shape. The resistance value of the metal layer is a value obtained by measuring the resistance value of the outermost surface of the roll-shaped sample. Table 1 shows the measurement results.

[0020]

[Table 1]

As apparent from Table 1, the resistance value of the metal layer after leaving for 4920 hours was 8.0 Ω in Examples 1 to 5, 26.3 Ω in Comparative Example 1 and the conventional example. 1 to Conventional Example 5 are 23.0 to 25.0Ω. That is, the resistance value of the metal layer of Example 1 to Example 5 was about 3 compared to Comparative Example 1 and Conventional Example 1 to Conventional Example 5.
It is reduced to a size of 4.8% or less. And Example 1
As is clear from Example 5 and Comparative Example 1, when the thickness of the protective layer is 3 Å or more, the effect of reducing the resistance value of the metal layer becomes remarkable.

The oxidation state of the metal layer was observed when the metallized films of the examples and comparative examples were left in an atmosphere of a temperature of 65 ° C. and a humidity of 70% RH. In addition, about the sample, the Example is the same conditions as the Example used in Table 1, except that the thickness of the protective layer is as shown in Table 2 and the heat treatment time is 24 hours. The conditions of the comparative example are the same as those of the comparative example used in Table 1. The oxidation state of the metal layer is obtained by observing the outermost surface of the roll. Table 2 shows the measurement results.

[0023]

[Table 2]

As is evident from Table 2, it is clear that the effect of preventing the oxidation of the metal layer is greater when the thickness of the protective layer is 3 Å or more. If the thickness of the protective layer is 800 angstroms, winding deviation is undesirably generated. Therefore, the thickness of the protective layer is preferably in the range of 3 to 700 Å.

[0025]

As described above, according to the first aspect of the present invention,
Since the capacitor element is formed by using a metallized dielectric in which a metal layer is laminated on a dielectric and this metal layer is covered with a protective layer made of a fluorine-based material and having a thickness of more than 1 Å, moisture resistance is improved. , The tan δ characteristics and the like can be improved, and the life of the capacitor can be improved.

According to the second aspect of the present invention, the metal layer is laminated on the dielectric, and the metal layer is covered with the protective layer made of a fluorine-based material and having a thickness of more than 1 Å. Is hardly oxidized by moisture or the like, and when used for a capacitor, a metallized dielectric for a capacitor that can improve tan δ characteristics and the like can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view of an embodiment of the invention of claim 2;

FIG. 2 is a sectional view of the first embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Metallized dielectric, 2 ... Dielectric, 3 ... Metal layer, 5
... Protective layer, 6 ... Capacitor element, 7 ... Capacitor.

Claims (2)

[Claims] In a capacitor having a capacitor element made of a metallized dielectric, a metal layer is laminated on the dielectric, and this metal layer is covered with a protective layer made of a fluorine-based material and having a thickness of more than 1 Å. A capacitor comprising a metallized dielectric. 2. A capacitor metallized dielectric in which a metal layer is laminated on a dielectric, comprising a protective layer made of a fluorine-based material covering the metal layer and having a thickness of more than 1 Å. Metallized dielectric.