JPS5972124A - Film condenser - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a film capacitor constructed from a coated aluminum foil and a vapor deposited film.

2. Description of the Related Art Conventional Structures and Their Problems Today, the competition for miniaturization of electric and electronic equipment is fierce, and there is a strong demand for miniaturization of each electronic component that constitutes the equipment. In order to perform high-density mounting of electronic components, the components need to be small and at the same time have high-temperature stability to withstand the soldering temperature during mounting. Among today's various electronic components, miniaturization.

It can be said that plastic film capacitors have been the slowest to respond to improvements in heat resistance.

In conventional film capacitors, as shown in Figure 1, aluminum is vapor-deposited on plastic films 1 and 1' to form electrodes 2 and 2', and these two weights are slightly shifted. After winding up the film, metal spraying (hereinafter referred to as metallization) is applied to both sides of the wound film to form vapor-deposited electrodes 2 and 2' and metal IJ contact electrodes 3 and 3'. Connect the lead wire 4.4"i to this
The structure is similar to that of connecting, but instead of the vapor-deposited electrode in Figure 1, two sheets of aluminum foil are used, and two sheets of aluminum foil and two sheets of plastic film are overlapped alternately and rolled up. It had a structure.

Of the two types of structures mentioned above, the former is effective in the high capacitance range, but in the low capacitance range of 10,000 PI" or less, the productivity is poor and it is difficult to mass produce, and the 250 to 260 At temperatures as high as ℃, the characteristics deteriorate significantly. Therefore, in the low capacity range, capacitors using the latter type of aluminum foil were the mainstream.

However, two pieces of aluminum foil and two pieces of film were used.
There is a limit to miniaturization with the method of winding up the sheets at the same time, and even with this type, it was difficult to avoid large characteristic deterioration during soldering.

OBJECTS OF THE INVENTION The present invention completely eliminates these drawbacks and provides a high-performance film capacitor mainly in the low capacity range.

Structure of the Invention The film condenser of the present invention consists of a short (It)-shaped aluminum foil on which a heat-resistant plastic dielectric layer is formed on one surface, aluminum vapor-deposited on one surface, and a layer of aluminum foil on the other surface. A heat-resistant plastic film in the form of a rectangular heat-resistant plastic film with aluminum vapor-deposited, leaving a certain width in the width direction, is placed so that the other surface of the aluminum foil and the other surface of the heat-resistant plastic face each other. , and the heat-resistant plastic is wound so as to be overlapped so that the undeposited part on the other side is exposed, and metal electrode layers are formed on both sides of the resulting wound body.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings. Second
The figure shows a developed perspective view of an embodiment of the present invention, and FIG. 3 shows a cross-section of the laminated structure taken along the line A-A' in FIG. In the film condenser of the present invention, a dielectric layer 6 is coated on the second side of the aluminum foil 5, and on the side of the plastic film 7 that does not come into contact with the aluminum foil 5, a metal serving as an electrode is deposited on the entire surface of the film to form an aluminum layer. An electrode 8 is formed facing the foil. On the other hand, on the side of the plastic film that contacts the aluminum foil 5, there are two cases in which a vapor-deposited aluminum electrode 8' is provided in a portion overlapping with the aluminum foil 5 as shown in the cross-sectional view of FIG. As shown in the figure, there are two types of structures in which aluminum is not vapor-deposited, both of which are included in the present invention.
t'Lru. In addition, when performing uneven aluminum vapor deposition on both sides of a plastic film as shown in Fig. 3, an undeposited part 9 is absolutely necessary except for the overlapped part of the plastic film and aluminum foil. Later, when I tried to extract the electrode sound from the side, I shorted it out and lost it. Now,
Now, the dielectric layer 6 coated on the aluminum foil 6
Let C be the electric capacitance of the plastic film, and C is the electric capacitance of the plastic film.
It can be found by (M+Cjp). When vapor deposition is performed on both sides of the plastic film as shown in FIG. 3, k=o, whereas when vapor deposition is performed on only one side as shown in FIG. 4, k becomes a kina value slightly larger than 0.

This k is the porosity created between the aluminum foil 5 and the plastic film 7 during winding.

The materials constituting the entire film capacitor of the present invention are aluminum foil, dielectric film, heat-resistant film, and sprayed metal. I will explain everything.

The aluminum foil is the base material of the dielectric layer and can also serve as one of the electrodes. Since the thickness is directly related to the shape of the element, it is preferable that the thickness be as thin as possible, and from the viewpoint of workability, a thickness of 40 μm or less is suitable.

The dielectric layer is preferably formed on the sialuminum foil by dissolving it in a solvent or by melt extrusion. One or a combination of heat-resistant thermoplastic resins, thermosetting resins such as epoxy resins, diallyl phthalate resins, acrylic resins, and crosslinked polybutadienes is used. As the heat-resistant film, a film made of the above-mentioned heat-resistant thermoplastic resin is used. Finally, the metal materials to be thermally sprayed include Al and Zn, which have good conductivity and are easy to thermally spray.
, Ni, etc. or a combination thereof. The film wound in this way is made by wrapping a heat-resistant film that has not been vapor-deposited several times, applying pressure under high temperature to self-fuse to prevent unwinding, and then pulling out the lead wire. By packaging, the film capacitor of the present invention is completed.

The features of the present invention can be summarized as follows: an element that can withstand the Nonda heat resistance test, easy winding and productivity, and miniaturization of the element in a low capacity range.

More specific examples of the present invention will be shown below.

(Example 1) Polyether sulfone was coated on a 12μ aluminum foil to a thickness of 2μ, and the foil was coated with a thickness of 6 mm and 10t1.
It was cut into a strip of π length. On the other hand, on one side of a polyether sulfone film with a thickness of 3 μm and a width of 6 mm, 200 to 500 aluminum was vapor-deposited on the entire surface, and on the other side, a margin part with a width of 1 M was formed on the - side. , 200 to 500 people were deposited in a 4-width area.
Cut it into long strips.

Next, as shown in FIG. 3, the plastic film 7 and the aluminum foil 5 are placed one on top of the other with a width of 4 mm, and the surface on which the aluminum foil is not coated and the surface of the film with the margin part face each other. The winding was performed by shifting the length of the winding, aligning the end faces at the beginning of the winding. After winding, the undeposited polyether sulfone film was wound two to three times, and the films were self-fused together using a heated iron. A zinc and nickel alloy was sprayed on both sides of the wound coil, and two lead wires were welded on top of that, connected to aluminum foil and vapor-deposited electrodes, and then covered with epoxy resin. . The characteristics of the device thus produced are shown in the AIK table below.

(Example 2) In Example 1, a 3 μm film of polyether sulfone was deposited on only one side, and the surface on which the aluminum foil was not coated and the surface on which the plastic film was not deposited faced each other. Using the same method as in Example 1, an element using aluminum foil and plastic film of the same dimensions was manufactured. Its characteristics are shown in Table 52.

(Example 3) A device was manufactured in the same manner as in Example 1 by coating polyphenylene oxide to a thickness of 2μ on 12μ aluminum-lamb seedling soil, and using a polyphenylene oxide film layer having a thickness of 3μ. Its characteristics are shown in Table 53.

(Example 4) Diaryl phthalate was placed on a 12μ aluminum foil for 2 hours.
A device was manufactured in the same manner as in Example 1 using a polysulfone film having a thickness of 3 μm. Its characteristics are shown in Table 4.

(Example 5) Cyclized polybutadiene (Japan Synthetic Rubber ■, trade name CBR-Mcao1) was applied to a thickness of 2 μm on a 12 μm aluminum foil, and the film f″L was cured by irradiation with ultraviolet rays. A device was manufactured using a 3μ thick film in the same manner as in Example 1. Its characteristics are shown in f5 in the table.

(Conventional example) Two pieces of 12μ aluminum foil are cut out to a width of 5mm and a length of IQrJn, and on the other hand, a piece of polyethylene terephthalate with a thickness of 4mm is cut out.
Two pieces of film each having a width of 6 mm and a length of 11 cm were cut out. As shown in Figure 5, the aluminum foil 1
0+ Film 11. Aluminum foils 1o and 10' are stacked one on top of the other in a 1M stack, like aluminum foil 10' and film 11', and the four sheets are wound at the same time. Metal spraying is applied to both sides of the wound coil to form aluminum foil 10. 10', and then welded lead wires to each of them and covered them. The characteristics of the conventional device are shown in the table.

(Reference example) 3 u to the stomach, 1 to the shoulder, 1 to the w surface of 11 sulfones, and 1 to 1 of the sulfone w surface.
I cut it out. As shown in Figure 1, the ζ5, etc. were rolled up while shifting one question at a time. After spraying metal on both sides, the lead wires were pulled out and packaged. The characteristics of the device thus manufactured are shown in the table.

In addition, the heat exchange test listed in the table was conducted by immersing the sample in a 270° C. bath for 10 seconds.

(Monday, 2013-46) Effects of the Invention As is clear from the above table, the film capacitor of the present invention has a larger capacity per unit volume than the conventional example, and the device is more compact. At the same time, the volume does not change before and after the heat distribution test, and there is no short circuit, making it extremely superior to conventional products. :, has the characteristics.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a conventional film capacitor, Fig. 2 is a developed perspective view of an embodiment of the film capacitor of the present invention, and Fig. 3 is a sectional view showing an embodiment in which aluminum is vapor-deposited on both sides of a plastic film. 4 is a sectional view showing an embodiment in which aluminum is vapor-deposited on one side of a plastic film, and FIG. 5 is a sectional view of a conventional film capacitor. 3...Sprayed metal electrode, 6...Aluminum foil, 6...Dielectric layer, End...Plastic film, 8.8'... ...Vapour-deposited electrode.

Claims (2)

[Claims] (1) A strip of aluminum foil with a heat-resistant plastic dielectric layer formed on one side, and one side with aluminum vapor-deposited and the other side with nothing or a constant width in the width direction. A strip-shaped heat-resistant plastic film on which aluminum has been vapor-deposited, leaving a A film capacitor characterized in that the film capacitors are stacked and wound so that the undeposited portions of the surfaces are exposed, and metal electrode layers are formed on both sides of the resulting wound body. (2) Heat-resistant plastics include polysulfone, polyethersulfone, polyimide, and fluorine resin. The film capacitor according to claim 1, characterized in that it is one or a combination of epoxy resin, diallyl phthalate resin, thermosetting acrylic resin, and crosslinked polybutadiene.