JPH0563008B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a method of manufacturing a multilayer film capacitor.

(Prior Art) In general, a laminated film capacitor is manufactured by laminating and winding a pair of metallized films, each of which has vapor-deposited electrodes on dielectric films offset from each other, around a large-diameter winding core.
The mother element formed with metallicon electrodes on both end faces is removed from the large-diameter winding core and cut in the radial direction with a rotary saw blade to form the vapor-deposited electrode 21 with a cut surface as shown in FIG. There are those that have margin portions 22 on both sides, and those that have vapor deposition electrodes 21 exposed on both sides as shown in FIG. In FIGS. 10 and 11, 23 is a dielectric film, and 24 is a metallicon electrode.

However, since the one shown in FIG. 10 has margin portions 22 on both sides, the effective capacitance per unit volume is limited, and the capacitance is also reduced due to mask displacement and scattering during vapor deposition during the formation of the vapor deposition electrode 21. The dielectric film 23 shown in FIG. 11 is thin, so there is a risk of short-circuiting between opposing electrodes or green surface discharge during cutting, resulting in poor reliability.

Therefore, Japanese Patent Publication No. 61-29533 is a technique aimed at eliminating these drawbacks.
The technique disclosed in this publication is a means of forming a margin of the vapor deposition electrode at the cut surface by chemically dissolving and removing the tip of the vapor deposition electrode exposed on both side surfaces by cutting, thereby obtaining the necessary and minimum margin. This is what we are trying to do.

However, it is difficult to control the invasion of chemical species, it is difficult to control the internal margin, and processes such as water washing of chemical species are required, which complicates the vapor deposition electrode margin formation process, and it is difficult to remove chemical species. However, there were problems with reliability.

(Problems to be Solved by the Invention) With the above-described means for forming a margin on a cut surface, it is difficult to control the margin formation dimensions, and water washing is required, which complicates the process and at the same time causes the chemical species to It was difficult to remove, resulting in a loss of reliability.

The present invention has been made in view of the above points, and it is an object of the present invention to provide a method for manufacturing a laminated film capacitor that has good workability and enables formation of an arbitrary vapor-deposited electrode margin on a cut surface with high accuracy. be.

[Structure of the Invention] (Means for Solving the Problems) The method for manufacturing a multilayer film capacitor of the present invention includes alternately laminating a plurality of metalized films each having a vapor-deposited electrode, leaving a blank space at one end in the length direction. Then, metallicon electrodes are formed on both end faces, and a part of the vapor deposited electrode is electrically discharged and removed along the cut surface of the obtained unit element by cutting the mother element, and a vapor deposited electrode margin is formed on the cut surface. It is characterized by this.

(Function) According to the above means, since the margin formation of the evaporation electrode on the cut surface is performed electrically, the margin formation can be easily controlled, and uniform margin formation without variation is possible. This can greatly contribute to improving reliability by securing a laminated film capacitor of the specified rating and having good characteristics, while at the same time simplifying the process and greatly contributing to improving workability and efficiency.

(Example) An example of the present invention will be described below. 1st
2 and 2 show a laminated film capacitor obtained according to the present invention. As a means for forming this capacitor 1, for example, as shown in FIG. A pair of metallized films 4 provided with electrodes 3 are laminated and wound around a large-diameter winding core (not shown), and metallicon electrodes 5 are provided on both end faces.
The mother element 6 formed with the above is removed from the large-diameter winding core and cut in the radial direction with a rotating saw blade.Then, as shown in FIG. 4, the metallicon electrodes 5 of the unit elements 7 obtained by cutting are collectively Then, a metal brush 10 applied with a negative potential is brought into contact with the cut surfaces 8 and 9 to remove the tip of the vapor deposition electrode 3, and a vapor deposition electrode margin 11 is formed on each of the cut surfaces 8 and 9. This is what happens.

Note that the current in this case varies depending on the applied voltage, but is suitably approximately 3 mH or less.

According to the method for manufacturing a multilayer film capacitor constructed as described above, as shown in FIG. 5, the dimension of the deposited electrode margin 11 is controlled by the applied voltage, and the discharge current is appropriately limited to prevent excessive energy from being discharged. By suppressing the evaporation electrode margin 11, it becomes possible to easily form the evaporation electrode margin 11 arbitrarily and uniformly.
There is no creeping discharge deterioration of the film as a dielectric material,
A multilayer film capacitor with no variation in capacitance or variation in insulation resistance can be easily obtained.

In the above embodiment, the unit element forming means is obtained by radially cutting a mother element formed by winding it around a large-diameter winding core, but as shown in FIG. As shown in FIG. 7, the metallized film strips 12 are laminated alternately, and the metallicon electrodes 13 are formed on both end faces of the mother element 14. It may be cut into a plurality of pieces in the direction.

Further, in the above embodiment, as a means for forming the vapor deposition electrode margin 11, a method of applying a positive potential to the metallicon electrodes 5 all at once and applying a negative potential to the cut surfaces 8 and 9 was explained as an example, but FIG. As shown, the same effect can be obtained by applying a positive potential to one cut surface 8 and applying a negative potential to the other cut surface 9.

Furthermore, in addition to the above explanation, as shown in FIG. 9, a resin 15 is applied to the surface on which the vapor deposition electrode margin 5 is formed,
It is more effective to improve reliability if the vapor deposition electrode margin 5 is sealed. Further, in this case, the same effect can be achieved even if the surface on which the vapor deposition electrode margin 5 is formed is thermally welded instead of using resin.

[Effects of the Invention] According to the present invention, it is easy to form a desired evaporated electrode margin on the cut surface, and a highly reliable multilayer film capacitor that eliminates various characteristics deterioration factors can be obtained, and a multilayer film capacitor with high practical value can be manufactured. How can you get it?

[Brief explanation of the drawing]

1 to 4 relate to an embodiment of the present invention, FIGS. 1 and 2 show a capacitor, FIG. 1 is a perspective view of the main parts, FIG. The figure is a partially expanded perspective view showing the mother element, FIG. 4 is a perspective view showing the vapor deposition electrode margin forming means, FIG. 5 is a correlation diagram between applied voltage and vapor deposition electrode margin depth, and FIGS.
FIG. 7 shows a mother element forming means according to another embodiment, FIG. 6 is a perspective view showing a stacked state of metallized films, FIG. 7 is a perspective view of the mother element, and FIG. 8 is a perspective view of another embodiment of the present invention. FIG. 9 is a perspective view showing a vapor deposition electrode margin forming means according to an embodiment, FIG. 9 is a side sectional view showing a capacitor according to another embodiment, and FIG. 10 and FIG. FIG. 2... Margin, 3... Vapor deposited electrode, 4... Metallized film, 5... Metallicon electrode, 6... Mother element, 7... Unit element, 8... Cut surface, 9... Cut surface, 11 ... Vapor deposition electrode margin, 13 ... Metallicon electrode, 14 ... Mother element, 15 ... Resin.

Claims (1)

[Scope of Claims] 1. A means for forming a mother element by alternately stacking a plurality of metallized films on which vapor-deposited electrodes are applied, leaving a margin at one end in the length direction, and forming metallicon electrodes on both end faces; means for cutting the mother element to obtain unit elements;
A method for manufacturing a multilayer film capacitor, comprising means for electrically discharging and removing a part of the vapor deposited electrode along a cut surface of the unit element to form a vapor deposit electrode margin on the cut surface. 2. The method for manufacturing a multilayer film capacitor according to claim 1, wherein the formation of a vapor deposited electrode margin on the cut surface is carried out by applying and discharging a voltage between the metallicon electrode and the cut surface. 3. The method of manufacturing a multilayer film capacitor according to claim 1, wherein the formation of a vapor deposition electrode margin on the cut surfaces is carried out by applying and discharging a voltage between the cut surfaces. 4. Claim 1, characterized in that the cut surface on which the vapor deposited electrode margin is formed is covered with a resin.
A method for manufacturing a multilayer film capacitor according to any one of items 1 to 3. 5. The method for manufacturing a multilayer film capacitor according to any one of claims 1 to 3, characterized in that the cut surface on which the vapor-deposited electrode margin is formed is covered by thermal welding.