JPH07183160A - Laminated film capacitor and its manufacture - Google Patents

Abstract

PURPOSE:To provide a safe and highly reliable laminated film capacitor. CONSTITUTION:A laminated film capacitor is manufactured by winding a belt- like film around a laminated capacitor element 1 by winding a heat shrinkable tube 2 around the element 1 and heat-shrinking the tube 2. Therefore, such a highly reliable laminated film capacitor that a vapor-deposited film and electrode material are not scattered nor catch fire nor fume can be easily produced at a low cost, since the holding strength of the element 1 in the direction of lamination is reinforced by the film.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated film capacitor and its manufacturing method.

[0002]

2. Description of the Related Art In recent years, film capacitors have been actively developed for miniaturization, high performance and cost reduction. Among them, laminated film capacitors are generally said to be easier to develop than conventional wound film capacitors. This is because the laminated film capacitor uses a method that is easy to mass-produce, and the film-layer adhesive strength is uniform over the entire element, and thus it is easy to obtain characteristics that do not vary.

However, laminated film capacitors are mostly used in the low voltage field. This is because it has a laminated cut surface structurally, and when a high voltage is applied to the laminated film capacitor, it does not function as a capacitor due to discharge at the laminated cut surface.

Therefore, recently, an attempt has been made to use a laminated film capacitor even in a high voltage field by devising a laminated cut surface. Due to this, it is expected that even in the high-voltage field, miniaturization, high performance, and cost reduction will be promoted by laminated film capacitors.

[0005]

However, this laminated film capacitor is used as a power source noise preventive method in order to prevent power noise, by using the explosion hazard test, fire hazard test, and fire hazard test, which are test methods of safety standards in North America (UL or CSA). B (UL.141
4.13 Discharge test of Across the Line Capacitor, Antenna Coupling and Line by Path Component by CSA. 10.
It is very difficult to apply it to the discharge test of across-the-line, antenna isolation or line-by-pass capacitors according to 6.1 and 10.6.3 to 4 because of structural problems. This is because the holding strength of the laminated capacitor element in the laminating direction is only the interlayer adhesive force of the film, so that the vapor deposition film and electrode material of the laminated capacitor element scatter in the case of the above test, which does not satisfy the test.

In view of the above problems, the present invention provides a multilayer capacitor applicable to at least an expansion hazard test and a fire hazard test (UL1414.13), which are test methods for safety standards in North America (UL or CSA), and a manufacturing method thereof. Is provided.

[0007]

In order to solve the above-mentioned problems, the laminated film capacitor of the present invention has a structure in which a dielectric film and electrodes are laminated and electrode portions are formed at both ends to form a capacitor element. In this structure, a strip-shaped film is wound around the outer periphery of the capacitor element.

The thickness of the layer formed by the strip-shaped film is not particularly limited, but is generally 0.00
A range of 5 mm to 2 mm and, if desired, 0.02 mm to 0.5 mm is suitable.

The holes formed in the band-shaped film are
The shape and the number of holes are not particularly limited, but generally, the aperture ratio is 0% to 50%, the strength, the gas escape property at the time of element breakdown, etc. should be desired to be 0% to 15%. The range is appropriate.

The positions of the holes formed in the band-shaped film are not particularly limited, but it is desirable to make holes in the layer-cut surface when the layer-cut film is coated on the layer-cut surface.

[0011]

With the structure of the present invention, the holding strength of the multilayer capacitor element in the stacking direction is reinforced by winding the strip-shaped film, so that the vapor deposition film and the electrode material do not scatter, and at least the expansion hazard test and the fire are performed. Hazard test test (UL141
4.13) can be easily satisfied at low cost.

Further, by making a hole in the band-shaped film, the holding strength in the laminating direction is reinforced and at the same time, the gas escape property at the time of element destruction is ensured and the electric short circuit of the film capacitor element is less likely to occur. , The expansion hazard test, the fire hazard test, and the fire hazard test B (UL1414.13 and CSA.10.6.1 and 10.6.3-4) can be easily satisfied at low cost in a well-balanced manner.

[0013]

EXAMPLES A laminated film capacitor of the present invention and a method for manufacturing the same will be described below with reference to Examples.

(Embodiment 1) As shown in FIG. 1, a polyester-based heat-shrinkable tube 2 as a strip-shaped film is provided between electrode portions 1a at both ends of a capacitor element 1 formed by laminating a dielectric film and electrodes. It is wrapped and reinforced by covering it with heat and shrinking it.

That is, the laminated capacitor element 1 is passed through the cylindrical heat-shrinkable tube 2 and left alone in the heat circulation tank for a predetermined time so that the heat-shrinkable tube 2 tightens the capacitor element 1 in the stacking direction. The wound capacitor element 1 can be easily obtained at low cost. The thickness of the tube 2 after the heat shrinkage was about 0.1 mm. In this example, the lead wire 3 was welded after being reinforced with a strip film.

The reinforced capacitor element 1 was packaged in a case 4 after being inserted into the case 4 in a packaging step to obtain a laminated film capacitor as shown in FIG.

(Embodiment 2) As shown in FIG. 3, two layers of polyester film 6 as a strip-shaped film are wound around a laminated capacitor element 1 and the capacitor element 1 is fastened in the laminating direction. The reinforced capacitor element 1 was then case-covered in a packaging process to form a laminated film capacitor as shown in FIG.

(Embodiment 3) As shown in FIG. 4, a laminated type capacitor element 1 is covered with a polyester type heat-shrinkable tube 7 as a strip-shaped film from above the electrode portion 1a and heat-shrinked to form a wound capacitor element. 1 is fastened in the stacking direction. Tube 7 after this heat shrink
The thickness was about 0.1 mm. Further, the lead wire 3 is connected to the electrode portion 1a before being covered with the heat shrinkable tube 7. Then, the reinforced capacitor element 1 was formed into a laminated film capacitor as shown in FIG.

(Embodiment 4) As shown in FIG. 5, a polyester type heat-shrinkable tube 8 having a hole 8a having an aperture ratio of 10% was used as a strip-shaped film and wound around a capacitor element 12 in the same manner as in Embodiment 1. It was

(Example 5) As shown in FIG. 6, a polyester type heat-shrinkable tube 9 having a hole 9a having an aperture ratio of 50% was used as a strip-shaped film, and was wound around a capacitor element 1 in the same manner as in Example 1. It was

(Comparative Example) A laminated film capacitor as shown in FIG. 7 was obtained by directly packaging the laminated capacitor element 1 without reinforcing the case in the packaging step.

The laminated film capacitor obtained as described above is used as a power supply noise prevention capacitor in the expansion hazard test, fire hazard test, fire hazard test B () which is a test method of safety standards in North America (UL or CSA). UL1414.13 and C
SA. The evaluation was performed at 10.6.1 and 10.6.3-4).

The results are shown in (Table 1).

[0024]

[Table 1]

As can be seen from Table 1, the comparative examples are North American safety standards (UL1414.13 and CSA.10.
It can be seen that the expansion hazard test and the fire hazard test according to 6.1 and 10.6.3 to 4) have failed.

On the other hand, in Examples 1 and 2 of the present invention, at least the expansion hazard test and the fire hazard test (UL1414.13) were passed, and Examples 3, 4 and In 5, the expansion hazard test, the fire hazard test, the fire hazard test B (UL14
14.13 and CSA. 10.6.1 and 10.
6. 3-4) has passed. From these results, it can be seen that the structure is effective according to the present invention.

Although the case exterior is used in the embodiments of the present invention, other exterior materials and exterior structures such as powder resin exterior may be used.

Although a polyester heat shrink tube and a film were used as the strip-shaped film, the present invention is not limited to this, and for example, polyethylene, vinyl chloride, polyolefin, polypropylene, polyphenylene sulfide, etc. may be used. Also, the effect of the present invention can be obtained.

Further, when the strip-shaped film is wound around the outer periphery of the capacitor element, after the strip-shaped film is wound, it can be fixed by adhesion to ensure the reinforcement, or the subsequent exterior process can be facilitated. . Examples of the method include a method in which a band-shaped film coated with an adhesive is used for adhesion, a method in which one or more layers of the band-shaped film are wound, and then thermocompression bonding is performed.

In Embodiment 1, Embodiment 2, Embodiment 4, Embodiment 5, and Embodiment 6 of the present invention, a strip-shaped electrode portion (generally formed by thermal spraying) of the multilayer capacitor element is used. Although the films are not in contact with each other, it is also possible to reduce the scattering of the electrode material during the test by covering a part of the electrode portion as in the third embodiment.

Further, FIGS. 8 to 11 show another embodiment of the present invention. First, the embodiment shown in FIG. 8 is obtained by winding the heat-shrinkable tube 8 so that the hole 8a is located on the upper surface of the capacitor element 1 and tightening the capacitor element 1 in the stacking direction in the embodiment shown in FIG. is there.

The embodiment shown in FIG. 9 is obtained by combining the embodiments shown in FIGS. 1 and 4 and winding the heat-shrinkable tubes 2 and 7 so as to cross each other.

The embodiment shown in FIG. 10 is similar to that shown in FIG.
In the embodiment shown in (2), two layers of a polyester film 10 having holes 10a having an opening ratio of 50% are wound in place of the heat-shrinkable tube 9.

Further, in the embodiment shown in FIG. 11, the strip-shaped film 11 having a width narrower than that of the capacitor element 1 is used.
2 are wound around different positions of the capacitor element 1. In this case, the narrow film 11 may be spirally wound around the capacitor element 1.

Needless to say, the welding of the lead wire 3 to the electrode portion 1a of the capacitor element 1 may be performed before or after the step of winding the strip-shaped film.

[0036]

As described above, according to the present invention, since the holding strength of the laminated capacitor element in the laminating direction is reinforced by the belt-shaped film, the vapor deposition film and the electrode material are less likely to scatter, and at least Expansion Hazard Test, Fire Hazard Test Test (UL
1414.13) could be easily satisfied at low cost.

Further, by making a hole in the band-shaped film, the holding strength in the laminating direction is reinforced and at the same time, it is possible to ensure the gas release property when the element is broken, so that the electrical short circuit state of the film capacitor element is less likely to occur. Expansion hazard test, fire hazard test, fire hazard test B (UL141
4.13 and CSA. 10.6.1 and 10.6.
3-4) can be easily satisfied at low cost.

[Brief description of drawings]

FIG. 1 is a perspective view showing a main part of a laminated film capacitor according to an embodiment of the present invention.

FIG. 2 is a side view showing a partially cross-sectional structure of the laminated film capacitor after packaging.

FIG. 3 is a perspective view showing a main part of a laminated film capacitor according to an embodiment of the present invention.

FIG. 4 is a perspective view showing a main part of a laminated film capacitor according to an embodiment of the present invention.

FIG. 5 is a perspective view showing a main part of a laminated film capacitor according to an embodiment of the present invention.

FIG. 6 is a perspective view showing a main part of a laminated film capacitor according to an embodiment of the present invention.

FIG. 7 is a side view showing a partial cross-section of the structure of a laminated film capacitor as a comparative example of the present invention.

FIG. 8 is a perspective view showing a main part of a laminated film capacitor according to an embodiment of the present invention.

FIG. 9 is a perspective view showing a main part of a laminated film capacitor according to an embodiment of the present invention.

FIG. 10 is a perspective view showing a main part of a laminated film capacitor according to an embodiment of the present invention.

FIG. 11 is a perspective view showing a main part of a laminated film capacitor according to an embodiment of the present invention.

[Explanation of symbols]

 1 Capacitor element 1a Electrode part 2,7,8,9 Heat shrink tube 8a, 9a, 10a Hole 6,10,11 Film

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kenji Kuwata 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (6)

[Claims] 1. A laminated film capacitor in which a dielectric film and an electrode are laminated and electrode portions are formed at both ends to form a capacitor element, and a strip-shaped film is wound around an outer peripheral portion of the capacitor element. 2. The laminated film capacitor according to claim 1, wherein the band-shaped film is provided with holes having an aperture ratio of 50% or less. 3. The laminated film capacitor according to claim 1, wherein a heat-shrinkable tube is used as the strip-shaped film. 4. The laminated film capacitor according to claim 3, wherein the heat-shrinkable tube is provided with a hole having an opening ratio of 50% or less. 5. A laminated film capacitor comprising: a step of forming a capacitor element; a step of winding a strip-shaped film around an outer periphery of the capacitor element; and a step of forming an outer cover so as to cover the whole thereafter. Production method. 6. A method for manufacturing a laminated film capacitor, which comprises a step of forming a capacitor element, a step of covering an outer peripheral portion of the capacitor element with a covering tube, and a step of forming an outer cover so as to cover the whole thereafter. .