JPS60213016A - Method of producing capacitor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a capacitor, in which a capacitor element is wrapped in a plastic film or a laminate film of a plastic film and a metal foil, and the film is fused to seal the capacitor, and particularly to the structure of an external terminal lead-out portion.

Conventionally, for example, in an electrolytic capacitor, capacitor paper is sandwiched between an anode foil and a cathode foil, and the capacitor element impregnated with electrolyte is placed inside a plastic film or a laminate film of a plastic film and a metal foil such as aluminum foil. There is a structure in which the image is collected and the four sides of the film are sealed.

In such a film package type capacitor, the film and the anode lead out terminal.

It is necessary to firmly fuse the film to the cathode lead-out terminal, and for this reason, films such as ethylene/vinyl acetate copolymer or ethylene/methacrylic acid copolymer film with polar groups added to the side chains are used.

However, these films have a low softening point of 60 to 80 DEG C. due to their chemical structure, and when used as a material for bagging capacitors, the maximum operating temperature is limited to 85 DEG C. The softening point is 100℃ to increase the operating temperature of the capacitor.
More than polyester.

It is also possible to use a chained high melting point plastic film such as polyamide or polyvinylidene fluoride, but these films have heat fusion properties with other films of the same material, but have little heat fusion property with foreign materials. It was either not present or extremely weak, making it unsuitable as a capacitor packaging material that requires fusion bonding with the lead-out terminal.

The present invention eliminates the above-mentioned drawbacks and provides a method for manufacturing a film package type capacitor that has improved operating temperature, airtightness, and stable electrical characteristics. As shown in Figure 1, 3FIJ laminates 1 to 3 films consisting of plastic film, aluminum foil, and plastic film (
1) is pressure-molded to create a recess for accommodating the capacitor element (2). The capacitor element (2) is made by sandwiching capacitor paper between the anode foil and the cathode foil and rolling it up, and crushing it flat to form an anode lead terminal (3) and a cathode lead terminal (
4) and connect the lead wires (5) to each of them. The portions of the anode lead terminal (3) and cathode lead terminal (4) exposed from the capacitor element (2) were previously treated with sulfuric acid or phosphoric acid.

A porous film (
6) is formed. The capacitor element (2) thus constructed contains an electrolytic solution and an impregnating agent and is housed in the recess of the laminate film (1) as described above. As shown in FIG. 2, the laminated film (1
) on top of the same or different laminate film (7)
Cover the four sides of the capacitor element (2) with a heat sealer and an ultrasonic sheath, then heat the laminate film (1) and (1).
fuse with. Note that when the laminate film is used by folding it back, it is sufficient to simply fuse the three sides together.

In the capacitor manufacturing method described above, the porous skin 111 (6) formed on the anode lead terminal (3) and the cathode lead terminal (4) has many micropores in the thickness direction of the film, so the laminate film is When (1) and (7) are fml, the softened plastic enters the micropores and acts as an adhesive anchor.

Due to this adhesive anchoring effect, even a high melting point plastic film containing many linear components, which has poor heat fusion properties with foreign substances, has the effect of firmly fusion bonding. Therefore, with the capacitor manufacturing method of the present invention, it is possible to obtain a capacitor that can be used at high temperatures, and it is also possible to obtain a strong fusing force, thereby reducing leakage of electrolyte, impregnating agent, etc. during high temperature use. .

Example 1 The flat parts of the anode and cathode lead terminals were soaked in a 3% oxalic acid solution (
(20℃) 50V, anodized for 10 minutes, anode foil,
Connect to cathode foil and wrap with kraft paper to 10V-4
1000 electrolytic capacitor elements each of 7 μF and 50 V-10 μF were produced. After impregnating the capacitor element with an electrolytic solution, it was crushed and housed between 3B laminated films made of low density polyethylene (150 μm) + aluminum foil (20 μm) + polyester (12 μTrL), and the surrounding area of the capacitor element was heated at 220°C i 5ec4 h / cal'
c The table below shows the leakage status of the electrolyte from the electrolytic capacitor that was heat-pressed. The conventional example has the same structure as the present invention except that the anode and cathode lead terminals are not anodized.

Example 2 The flat parts of the anode and cathode lead terminals were soaked in a 10% sulfuric acid solution (1
Figure 3 shows the capacitance change rate in a 105°C load life test of an electrolytic capacitor with a rating of 50V-10μ, which was subjected to Ill polar oxidation for 20 minutes at 0°C>20V.
nδ is shown in FIG. 4, where curve (A) shows the present invention and curve (8) shows the conventional example. The film used was a three-layer laminate film consisting of high-density polyethylene (100 μm) + aluminum foil (30 μm) + polypropylene (10 μm), and had the same structure as Example 1 except for this. The conventional example has the same structure as the present invention except that a material that is not anodized is used.

As described above, according to the capacitor manufacturing method of the present invention, even a high melting point plastic film has a strong adhesive strength, so it can be used at high temperatures and has a capacitance of 51. A capacitor with excellent tan δ characteristics can be obtained. In the example, a case was described in which a recess was formed in the laminate film, but the recess may be difficult to form due to the flatness of the capacitor element.
It is determined whether it is unnecessary or not, and it is not essential.

[Brief explanation of the drawing]

The drawings all show embodiments of the present invention, and Fig. 1 is a perspective view showing a state in which a capacitor element is accommodated in a laminate film with a recessed part, and Fig. 2 is a perspective view showing a state in which a laminate film containing a capacitor element is fused. Perspective view shown, 3rd
The figure is a curve diagram showing the capacitance change rate of a capacitor, and FIG. 4 is a curve diagram showing tan δ of a capacitor element. (1)... Laminating film (2)...
... Capacitor element (3) ... Anode lead-out terminal (4) ... Cathode lead-out terminal (5) ... Lead wire (6) ... Porous Film (7)... Laminated film patent applicant Marcon Electronics Co., Ltd.

Claims (3)

[Claims] (1) In a method for manufacturing a film package type capacitor, in which a capacitor paper with anode and cathode lead-out terminals is housed between laminate films, and the laminate film is fused and sealed, the anode and cathode lead-out terminals exposed from the capacitor element are 1. A method for producing a capacitor, which comprises: anodizing a terminal portion in advance to form a porous film; and heat-sealing the surrounding area of a capacitor element including the porous film. (2) The method for manufacturing a capacitor according to claim (1), wherein the anodization is performed using sulfuric acid, phosphoric acid, or oxalic acid. (3) A method for manufacturing a capacitor according to claim (1) or (2), characterized in that three or four sides of the laminate film are heat-fused.