JP2002289459A - Metallized film capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain a metallized film capacitor having no risk of firing and burning of a capacitor element at the time of the eventual breakdown of the element. SOLUTION: In the metallized film capacitor 10 constituted such that a plurality of pairs of metallized films 18 formed by depositing each electrode film 16 composed of a metallic material on the surfaces of two dielectric films 12 in such a way that each margin part 14 is left along one side surface of each dielectric film 12 are stacked or wound by lamination in such a way that marginal parts 14 of the plurality of pairs of the metallized films 18 are arranged on the opposite side to each other to form a capacitor element 20 and at the same time, electrode materials are made to adhere on both end surfaces of the element 20 to form outer electrodes 22, gas adsorption materials 28 formed into cap shapes are bonded to the outer surfaces of the above electrodes 22 in such a way as to cover the electrodes 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metallized film capacitor, and more particularly to a metallized film capacitor capable of preventing ignition and burning at the time of ultimate destruction of a capacitor element.

[0002]

2. Description of the Related Art Conventionally, a metallized film capacitor using a capacitor element formed by laminating or winding a metallized film obtained by depositing an electrode metal on the surface of a dielectric film causes partial breakdown of the capacitor element. However, since it is excellent in self-healing property for restoring insulation again, it is widely used in various electric / electronic devices including household electric appliances.

FIG. 9 shows an example of such a metallized film capacitor. This metallized film capacitor 80 has electrode films 84 on the surface of a dielectric film 82, respectively.
After laminating a pair of metallized films 86 on which
Winding is performed by a winder (not shown) to fix the terminal end, and heat and pressure are applied thereto to form a capacitor element 88. External electrodes (metallicon electrodes) 90 are formed on both end faces of the capacitor element 88. It is manufactured by doing. On the surface of the dielectric film 82, a margin portion 92 (a portion not covered by the electrode film 84) is secured with a predetermined width along one side. Also, on the surface of the other dielectric film 82, a similar margin portion 92 is formed along the side opposite to the above.
Is secured.

[0004]

In the metallized film capacitor 80 having the above-described structure, even if a partial dielectric breakdown occurs in the dielectric film 82 and the electrode films 84 are short-circuited, the self-recovery property is immediately restored. Although it has recoverability, if an abnormal surge voltage is applied many times or if it is used for a long time, the dielectric film 82 that constitutes the capacitor element 88 deteriorates to cause partial breakdown. The frequency of occurrence increases, and the partial discharge accompanying the dielectric breakdown and the rise in temperature due to the partial discharge further promote the deterioration, and eventually lead to the ultimate breakdown. However, even in this state, since the metallized film capacitor 80 does not become a complete short circuit due to the self-healing function, an external safety device such as a current fuse or a breaker cannot operate, and the state where power supply is continued is considered. Become. For this reason, there is a danger that the capacitor element 88 will be ignited or burned by flammable gas generated by the decomposition of the dielectric film 82 due to the subsequent partial discharge and an abnormal temperature rise caused by the partial discharge.

The present invention has been devised to solve the above-mentioned problems of the prior art, and there is no danger of the capacitor element being ignited or burnt out when the capacitor element is finally destroyed. The purpose is to realize.

[0006]

In order to achieve the above-mentioned object, a metallized film capacitor according to the present invention has a metal material on a surface of a dielectric film such that a margin is left along one side. A plurality of metallized films formed by evaporating an electrode film comprising, laminated such that the margins between the plurality of metallized films are arranged on the opposite side, or rolled and laminated to form a capacitor element, In a metallized film capacitor in which an electrode material is attached to both end surfaces of the capacitor element to form external electrodes, a gas adsorbent is disposed inside the capacitor element or near the capacitor element and / or the external electrode. It is characterized by comprising.

In the metallized film capacitor of the present invention, when the capacitor is finally destroyed, the dielectric film is decomposed due to partial discharge and an abnormal temperature rise caused by the partial discharge, and flammable gas is generated. Also, since the combustible gas can be adsorbed by the gas adsorbent disposed inside the capacitor element or in the vicinity of the capacitor element and / or the external electrode, there is no danger of the capacitor element being ignited or burnt.

The above-mentioned gas adsorbent is formed, for example, in the form of a cap and then joined so as to cover the outer surface of the external electrode.
Also, after being formed into a sheet shape, it is arranged near the capacitor element and / or the external electrode by winding it around the outer surface of the capacitor element.

Further, an outer covering made of a gas adsorbing material is formed on the outer surface of the capacitor element and the outer electrode, or a gas adsorbing material is formed inside the outer covering formed on the outer surface of the capacitor element and the outer electrode. By mixing, the gas adsorbent can be arranged near the capacitor element and / or the external electrode.

In addition, a pair of metallized films are laminated so that their respective margins are disposed on opposite sides, and wound around a cylindrical core to form the capacitor element. By inserting a gas adsorbent inside the capacitor element, the gas adsorbent can be disposed inside the capacitor element.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first metallized film capacitor 10 according to the present invention is, as shown in FIGS. 1 and 2, provided on a surface of a pair of dielectric films 12 made of polypropylene, polyethylene or the like. An electrode film 16 made of a metal material such as aluminum or zinc is deposited with a thickness of 10 nm to 80 nm to form a pair of metallized films 18 so that the margin portion 14 is left along the side, and a pair of metallized films 18 are formed. Metallized film
After laminating so that the respective margin portions 14 of 18 are arranged on the opposite side (FIG. 1), they are wound by a winder (not shown) to fix the end portions, and subjected to heat and pressure treatment. Forming a capacitor element 20;
An external electrode (metallicone electrode) 22 is formed by adhering a molten electrode material such as solder or copper to both end surfaces of 20. One end of a lead terminal 24 is connected to the external electrode 22 via solder 26, and a cap-shaped gas adsorbent 28 is formed on the outer surface of the external electrode 22 to which the lead terminal 24 is connected. , So as to cover the external electrodes 22. The other end of the lead terminal 24 passes through a hole 30 formed in the cap-shaped gas adsorbent 28 and is led out of the gas adsorbent 28.

As the gas adsorbent 28, a molecular sieve or activated carbon can be suitably used. Molecular sieves are mainly composed of Al ₂ O ₃ ,
It is a porous insulating material having pores with a uniform pore diameter, and has an action of adsorbing gas molecules in the pores. This molecular sieve activates when heat energy is applied,
The attraction force increases.

In the first metallized film capacitor 10, when the capacitor is finally destroyed, the dielectric film 12 is decomposed due to the partial discharge and an abnormal temperature rise caused by the partial discharge, and the flammable gas is removed. Even if generated, the flammable gas can be adsorbed by the gas adsorbing material 28 bonded to the outer surface of the external electrode 22, so that there is no danger that the capacitor element 20 will be ignited or burnt.

FIGS. 3 and 4 show a second metallized film capacitor 32 according to the present invention. In this second metallized film capacitor 32, a gas adsorbent formed in a sheet shape is used. The first metallized film capacitor 10 is different from the first metallized film capacitor 10 in that the material 28 is wound around the outer surface of the capacitor element 20, and the other configuration is the same as the first metallized film capacitor 10.

In the second metallized film capacitor 32, when the capacitor is finally destroyed,
Even if the dielectric film 12 is decomposed due to the partial discharge and an abnormal temperature rise caused by the partial discharge, a flammable gas is generated, the flammable gas is wound on the outer surface of the capacitor element 20 in a sheet-like gas adsorbent. Since the capacitor element 20 can be adsorbed, there is no danger of the capacitor element 20 being ignited or burnt.

FIG. 5 shows a third metallized film capacitor 34 according to the present invention. In the third metallized film capacitor 34, one end of a substantially L-shaped lead terminal 24 is connected to the external electrodes 22 on both end surfaces of the capacitor element 20 via solder 26, and the lead Terminal
The present embodiment is characterized in that an outer covering 36 made of a gas adsorbing material is formed on the outer surfaces of the capacitor element 20 and the external electrode 22 of the connected capacitor 24. The above outer covering 36
Can be formed by dipping the condenser 34 in the gas adsorbent in a liquid state and then curing the gas adsorbent.

In the third metallized film capacitor 34, when the capacitor is finally destroyed,
Even if the dielectric film 12 is decomposed due to the partial discharge and an abnormal temperature rise caused by the partial discharge, a flammable gas is generated, the flammable gas is covered with an outer covering made of a gas adsorbent.
Capacitor element because it can be absorbed by 36
There is no danger of ignition or burning of 20.

FIG. 6 shows a fourth metallized film capacitor 38 according to the present invention. The fourth metallized film capacitor 38 has a powdery gas contained in an outer covering 40 made of resin or the like. The feature is that the adsorbent 28 is mixed. That is, in the fourth metallized film capacitor 38, one ends of the substantially L-shaped lead terminals 24 are connected to the external electrodes 22 on both end surfaces of the capacitor element 20 via the solder 26, respectively. The capacitor 38 to which the lead terminal 24 is connected is housed in a case 42 made of an insulating material such as resin or ceramic, and the lead terminal
The other end of 24 is led out of the case 42, and the inside of the case 42 is filled with a resin material such as urethane resin mixed with the powdery gas adsorbent 28, and then cured to form a capacitor 38 (capacitor 38). On the outer surfaces of the element 20 and the external electrodes 22), an outer covering 40 mixed with a gas adsorbent 28 is formed. The outer cover 40 on the outer surface of the capacitor 38
Can be formed by a resin dipping method.

Thus, in the fourth metallized film capacitor 38, when the capacitor is finally destroyed,
Even if the dielectric film 12 is decomposed by a partial discharge and an abnormal temperature rise caused by the partial discharge to generate a flammable gas, the flammable gas is mixed by the gas adsorbent 28 mixed in the outer coating 40. Since it can be adsorbed, there is no danger of the capacitor element 20 igniting or burning.

FIG. 7 shows a fifth metallized film capacitor 44 according to the present invention. The fifth metallized film capacitor 44 has a pair of metallized films 18 and a margin portion 14. After lamination so as to be disposed on the opposite side, these pair of metallized films 18 are wound around a cylindrical core 46 made of resin and the terminal ends are fixed to form the capacitor element 20, Furthermore, after inserting sealing plugs 48 at both ends of the core 46, a molten electrode material such as solder or copper is attached to both end surfaces of the capacitor element 20 to form external electrodes (metallicon electrodes) 22. Consisting of The sealing plug 48 is provided to prevent the molten electrode material from entering the inside of the core 46 and forming a short circuit between the external electrodes 22 and 22 when the external electrode 22 is formed. Is characterized in that the sealing plug 48 is made of a gas adsorbent.

Thus, in the fifth metallized film capacitor 44, when the capacitor is finally destroyed,
Even if the dielectric film 12 is decomposed due to the partial discharge and an abnormal temperature rise caused by the partial discharge to generate a flammable gas, the flammable gas is supplied to the sealing plug 48 made of a gas adsorbent.
Can be absorbed by the capacitor element 20
There is no danger of ignition or burning.

FIG. 8 shows a sixth metallized film capacitor 50 according to the present invention. In this sixth metallized film capacitor 50, a gas adsorbent 28 is provided inside a winding core 46. It has a characteristic in that it is inserted and arranged. Further, sealing plugs 52 made of resin are inserted into both ends of the core 46.

Thus, in the sixth metallized film capacitor 50, when the capacitor is finally destroyed,
If an abnormal temperature rise occurs due to partial discharge, the core 46
Is melted, and as a result, the inside and outside of the core 46 are in communication with each other. Therefore, the dielectric film is caused by the partial discharge and the abnormal temperature rise caused by the partial discharge.
Even if the flammable gas is generated by decomposition of the flammable gas 12, the flammable gas can be adsorbed by the gas adsorbing material 28 disposed inside the core 46. Absent.

[0024]

According to the metallized film capacitor of the present invention, when the capacitor is finally destroyed, the dielectric film is decomposed due to partial discharge and an abnormal temperature rise caused by the partial discharge, and flammable gas is generated. Even so, the combustible gas can be adsorbed by the gas adsorbent disposed inside the capacitor element or in the vicinity of the capacitor element and / or the external electrode, so that the capacitor element may be ignited or burnt. Absent.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a laminated state of a pair of metallized films in a first metallized film capacitor according to the present invention.

FIG. 2 is a sectional view showing a first metallized film capacitor according to the present invention.

FIG. 3 is a perspective view showing a second metallized film capacitor according to the present invention.

FIG. 4 is a sectional view showing a second metallized film capacitor according to the present invention.

FIG. 5 is a schematic sectional view showing a third metallized film capacitor according to the present invention.

FIG. 6 is a schematic sectional view showing a fourth metallized film capacitor according to the present invention.

FIG. 7 is a sectional view showing a fifth metallized film capacitor according to the present invention.

FIG. 8 is a sectional view showing a sixth metallized film capacitor according to the present invention.

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

[Explanation of symbols]

 10 First metallized film capacitor 12 Dielectric film 14 Margin 16 Electrode film 18 Metallized film 20 Capacitor element 22 External electrode 28 Gas adsorbent 32 Second metallized film capacitor 34 Third metallized film capacitor 36 Gas Exterior coating made of adsorbent 38 Fourth metallized film capacitor 40 Exterior coating made of resin etc. 44 Fifth metallized film capacitor 46 Core 48 Sealing plug made of gas adsorbent 50 Sixth metallized film capacitor

Claims (6)

[Claims] A plurality of metallized films formed by depositing an electrode film made of a metal material on a surface of a dielectric film so that a margin portion is left along one side; A metallized film formed by laminating or winding and laminating such that the margin portion is disposed on the opposite side, and forming external electrodes by adhering electrode materials to both end surfaces of the capacitor element. A metallized film capacitor, wherein a gas adsorbent is disposed inside the capacitor element or near the capacitor element and / or the external electrode. 2. The metallized film capacitor according to claim 1, wherein the gas adsorbent is formed in a cap shape and is joined so as to cover the outer surface of the external electrode. 3. The metallized film capacitor according to claim 1, wherein the gas adsorbent is formed in a sheet shape, and is wound around an outer surface of the capacitor element. 4. The metallized film capacitor according to claim 1, wherein an outer covering made of a gas adsorbent is formed on the outer surfaces of the capacitor element and the external electrodes. 5. An exterior coating is formed on the outer surfaces of the capacitor element and the external electrodes, and
2. A gas adsorbent is mixed.
4. The metallized film capacitor according to any one of claims 1 to 3. 6. A pair of said metallized films are laminated so that their respective margins are disposed on opposite sides, and wound around a cylindrical core to form said capacitor element. The metallized film capacitor according to any one of claims 1 to 5, wherein a gas adsorbent is inserted inside the core.