JPS6357932B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a metallized film capacitor, which is constructed by winding or laminating a metallized film in which a metal electrode is formed by vapor deposition or the like on the surface of a dielectric film. .

Conventionally, metallized film capacitors have been manufactured by the method described below. First, the first
As shown in the figure, on both sides of a dielectric film 1 such as polypropylene film, polyester film, or polycarbonate film, metal electrodes 2 made of aluminum, zinc, etc. are applied by vacuum evaporation or the like to the ends of the dielectric film 1 in the width direction for 1 mm. By forming a non-metalized part 3 of about ~5 mm,
After obtaining a double-sided metallized film and applying a dielectric layer 4 of polycarbonate, acetyl cellulose, etc. to both sides of the metallized film, this is wound, and then zinc,
A metal material such as tin, copper, or lead is thermally sprayed to form an electrode lead-out part 5, and a lead wire 6 is connected to the electrode lead-out part 5 by welding or the like to obtain a capacitor element, and a suitable exterior is applied to the capacitor element. A capacitor is obtained by applying

In addition to these wound-type capacitors, many multilayer capacitors are also produced, and in this case, they are often manufactured by winding them around a bobbin and then cutting them, but the basic structure is is almost the same as the wound type.

By the way, in the metallized film capacitor manufactured in this way, the non-metalized portion 3 is used for the purpose of preventing the metal electrode 2 from coming into contact with the electrode extension part 5 on the opposite side when the electrode extension part 5 is formed. This non-metalized portion 3
It is necessary that the capacitor has insulation properties that can withstand the voltage applied when using a capacitor. Due to this insulation requirement, conventional film capacitors, even those with low rated voltages, have a narrow width of the non-metallic part.
It was common to provide a thickness of about 1.0 mm.

However, this non-metalized portion 3 does not contribute to the capacitance of the capacitor at all and is a loss portion. Therefore, in the case of a capacitor in which the width of the metal electrode 2 that contributes to capacitance, that is, the width of the counter electrode is relatively large, the width of the non-metalized portion 3 is not a very important issue, but the width of the counter electrode In the case of capacitors with small capacitors, there are important issues in terms of material costs, capacitor shape, etc.

By the way, the formation of the non-metal evaporated portion as the non-metalized portion is achieved by continuously performing metal evaporation on the evaporation substrate during the evaporation process, and while creating the non-metal evaporation portion in the necessary areas, the evaporation process is continued. There is a need to proceed.

To address this need, there are known tape mask methods in which the necessary portions as non-metal vapor deposition portions are covered with tape and oil mask methods in which oil is applied to the necessary portions.

However, in the tape mask method, the heat-resistant tape is moved to cover the required area, and the vapor-deposited metal is attached to the heat-resistant tape to obtain the required area, so the width of the tape is In order to withstand mechanical strength, a width of 2 mm or more is generally required, and since the tape is moving, the accuracy of the non-metal evaporated part is about ±0.5 mm, so the tape method has an extremely narrow width of 1 mm or less. It is difficult to form non-metallic deposited parts.

On the other hand, in the oil mask method, when performing metal vapor deposition processing, oil is sprayed onto the film from the nozzle of an oil evaporator to the non-metal vapor deposition area that needs to be deposited in advance, and the deposited metal vapor forms a film. This method takes advantage of the fact that it cannot be formed. In addition,
In this method, most of the oil adhering to the film evaporates in a vacuum apparatus that performs metal vapor deposition.

However, the minimum width of the non-metal evaporated area obtained by this oil mask method is approximately 1 mm, and
A deviation (deposition blur) of about 300 μm occurs at the periphery.

The present invention was made with the aim of solving the problems of this oil mask method.
The purpose of the present invention is to provide a manufacturing method capable of forming a non-metal evaporated portion with an extremely narrow width. That is, the present invention is characterized in that an appropriate amount of oil that prevents the formation of vapor metal nuclei is left behind during metal deposition without being evaporated, thereby forming a non-metal deposition part with an extremely narrow width. It is. Hereinafter, it will be explained in more detail based on specific examples.

Aluminum was vacuum deposited to a thickness of 300 Å to 600 Å on a polyethylene terephthalate film 7 having a thickness of 3.5 μm using a vacuum evaporator shown in FIG. At this time, the polyethylene terephthalate film 7 is unwound from the take-up shaft 8 and fed sequentially through rollers, and is coated with insulating oil sprayed from the nozzle of the oil evaporator 9 to a thickness of 200 to 30,000 Å. , and is cooled from the back side by a cooling can 10. Then, while being cooled from the back side by another cooling can 11, aluminum evaporated from the vapor deposition source 12 is vapor-deposited and then wound onto the winding shaft 13.

Here, it is preferable that the temperature of the cling canisters 10 and 11 is as low as possible.

FIG. 3 shows a part of the metallized film deposited by the method of the present invention before being wound onto the winding shaft 13, in FIG. 15 is the non-metallized portion, and 16 is the residual oil.

Here, FIGS. 4 to 6 show a comparison of the non-metalized portions of a metallized film obtained by the conventional oil mask method and a metallized film obtained by the method of the present invention. In addition, in FIGS. 4 to 6,
A is the dimension of the nozzle discharge port of the oil evaporator 9, and B is the dimension of the vapor deposition blur around the non-metalized portion 15 after vapor deposition.

Further, FIG. 7 shows the relationship between the amount of residual oil in the non-metalized portion 15 and the size of the vapor deposition blur.

FIG. 4 shows a conventional method in which vapor deposition is performed without cooling using cooling cans 10 and 11, and the amount of residual oil in the non-metalized portion 15 is 0 to 50 Å.
range of thickness. The size of the vapor deposition blur is approximately 300 μm as shown in FIG.

Further, FIG. 5 shows the method of the present invention, in which insulating oil is sprayed from a nozzle of an oil evaporator 9 onto a polyethylene terephthalate film 7 as a dielectric film so as to adhere to a thickness of 200 Å to 2200 Å. Next, the oil in the non-metalized portion 15 is cooled by cooling cans 10 and 11. At this time, the temperature of the cooling cans 10 and 11 should be as low as possible as described above, and in the experiment, the temperature was between -20°C and -40°C. Also,
If the cooling capacity of the cooling can 11 is sufficient,
Even if the cooling can 10 is omitted, the same effect can be obtained. Furthermore, the injection amount from the oil evaporator 9 and the cooling canister 1 are adjusted such that the residual oil in the non-metalized portion 15 after metal deposition is 150 Å to 2000 Å.
The temperature was adjusted to 0.11.

In this way, when the residual oil has a thickness of 150 Å to 2000 Å, the vapor deposition blur becomes very small as shown in FIG. I can do it. Here, in order to deposit oil with a uniform thickness from the nozzle of the oil evaporator 9 onto the polyethylene terephthalate film 7 as the evaporation substrate, it is better to bring the polyethylene terephthalate film 7 into contact with the nozzle of the oil evaporator 9. According to experiments, the nozzle width is 0.05mm.
It was possible to form the non-metalized portion 15 up to this point.

Further, FIG. 6 shows a case where the residual oil in the non-metallized portion 15 exceeds a thickness of 2000 Å in the method according to the present invention. If it exceeds this, vapor deposition blur will occur. This is because the amount of injection from the nozzle of the oil evaporator 9 was too large, causing the oil to flow laterally and spread out, causing vapor deposition blur.

As described above, according to the method for manufacturing a metallized film capacitor of the present invention, the evaporation substrate is brought into contact with the nozzle of the oil evaporator, and the non-metalized portion is cooled before or during passing over the metal evaporator. By adjusting the residual oil in the non-metalized part to 150 Å to 2000 Å, it is possible to form a non-metalized part with an extremely narrow width, that is, to make the width of the non-metalized part much narrower than the conventional 1 mm. Capacitance loss in the metallized portion is significantly reduced, making it possible to obtain a smaller capacitor.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing the schematic structure of a conventional metallized film capacitor, and FIG. 2 is an example of a vacuum evaporation machine used to manufacture a metallized film in the method for manufacturing a metallized film capacitor according to the present invention. 3 is a cross-sectional view showing an example of a metallized film obtained by the same method, FIG. 4 is a cross-sectional view showing essential parts of an example of a metallized film obtained by the conventional manufacturing method, and FIG. The figure is a sectional view showing the main part of the metallized film obtained by the method of the present invention, and Figure 6 shows the structure of the main part of the metallized film when the residual oil amount is not set to a predetermined value in the method of the present invention. The cross-sectional view shown in FIG. 7 is a diagram showing the relationship between the amount of residual oil in the metallized film and the size of the vapor deposition blur in the method of the present invention. 7...Polyethylene terephthalate film,
10, 11...Cooling canister, 14...Metal electrode, 15...Non-metalized portion, 16...Residual oil.

Claims (1)

[Claims] 1. When a metallized film is obtained by forming a non-metalized portion by an oil mask method, the film is cooled before or when the non-metalized portion of the metallized film passes over a metal evaporator. , a method for manufacturing a metallized film capacitor, characterized in that the amount of residual oil is made to have a thickness of 150 Å to 2000 Å.