JPS5915062Y2 - metallized plastic film capacitor - Google Patents

Description

[Detailed description of the invention] This invention is a product made by winding a metalized film.
This invention relates to a metallized film capacitor that has improved tan δ and current intensity by stabilizing the connection between an electrode film and a metallized metal.

Conventional metallized film capacitor in which a pair of metallized films having an electrode film consisting of a vapor-deposited part and a non-evaporated part are shifted in the width direction and overlapped and wound, and an electrode lead-out part is provided on the end face of the wound body using metallicon or the like. was known.

It is desirable that the displacement in the width direction of the metal film is as small as possible, but it is currently set to about 1 mm because meandering phenomena due to the precision of the winder, expansion and contraction of the film, etc. cannot be avoided.

Due to this meandering phenomenon, the non-evaporated portion may form the end face of the wound body, resulting in the disadvantage that the metallicon metal is not connected to the electrode or conduction is incomplete.

In recent years, with the increase in the number of applications in which large currents are passed through capacitors, such as in high-frequency pulses, the number of disconnection accidents in metallized parts has increased, and the current strength of the metallized parts has become more important.

In order to investigate this disconnection accident, the inventors observed the connection between the metallcon part and the electrode, and found that in this type of capacitor element, the end face of the plastic film 1 of the wound body was extremely uneven, as shown in Figure 1. , and film 1
The gap between the two electrodes is only two thicknesses of the film of the other pole, but even though the width direction shift is around 1 mm, the gap between the films is 0.
0.004 to 0.016 mm (that is, approximately the film thickness), it may shrink or bend due to tightening of the wound body, heat treatment, heat and pressure during metallization, etc.
It was discovered that the connection with the computer was unstable.

Note that 3 is an electrode film deposited on the film 1, and 4 is an electrode portion deposited on the film 2 of the other electrode.

The present invention was developed in view of the above points, and aims to stabilize the connection between the electrode film formed in the film and the metallicon, thereby improving tan δ and the current intensity at the connection portion. be.

This will be explained below using examples.

Example 1 As shown in FIG. 2, an electrode film 13 was formed by depositing AI on one end of a polypropylene film 11 (hereinafter referred to as PP film) with a thickness of 9 μm and a width of 20 mm, leaving a 2 mm non-deposited portion 12. Further, an auxiliary electrode 14 having a width of 4 mm was formed on the back surface of the non-evaporated portion 12.

The membrane resistance of the electrode film 13 is 2Q/cm2.

A capacitor element having a rating of 250 V-0.1 .mu.F was constructed by winding the metalized PP film 1 with the sheets shifted by 1.5 mm from each other.

Therefore, in the combination of the electrode film 13 and the auxiliary electrode 14, as is clear from the figure, the auxiliary electrode formed on the back surface of one electrode film comes into contact with the other electrode film.

The outer circumferential surface of such a capacitor element was clamped with a clamping jig and pressed by applying a pressure of 50 kg/cm2, and the clamping jig was fixed in that state.

Zn is thermally sprayed onto both end surfaces of the capacitor element fixed in this pinched state to form electrode lead-out portions 15.
After heating at 10° C. for 1.5 hours, the capacitor element was removed from the clamping jig.

Lead wires are connected to the electrode extensions formed on both end faces of the condenser element using solder, etc., and this is then covered with resin.5
The five tan δ characteristics are shown in FIG. 3, and the frequencies are indicated by marks.

In addition, 55 samples without the auxiliary electrode of the present invention but with the same conditions as before were prepared and used as a conventional example, and the tan δ characteristics are also shown in FIG. 3, where the frequency is indicated by an x mark.

Example 2 A sample of the present invention using 30 samples prepared in the same manner as Example 1 with a rating of 250V-0.2μF was applied to a sample of the present invention at 300V 60
The tan δ characteristics before and after the test when a pulse current of 0 A was passed 100,000 times are shown in FIGS. 4 and 5.

FIG. 4 shows the frequency of tan δ values before the test, and FIG. 5 shows the frequency of tan δ values after the test.

Similar pre-test characteristics of the conventional example are shown in FIG. 6, and similar characteristics after the test are shown in FIG. 7.

The metallized plastic film of the present invention is the 8th.
As shown in the figure, it can be obtained by forming electrode films alternately on both the front and back surfaces and cutting them.

Note that the dotted line indicates the cutting location. As is clear from the above results, in the metallized plastic film capacitor according to the present invention, even if the capacitor element is heated and pressurized by the auxiliary electrode 14 formed on the back surface of the non-evaporated part of the electrode film 13, it is clear that the capacitor element does not come into contact with the electrode extension part 15. is in good condition so jan
The δ characteristics are stable and the pulse current test shows excellent results as described above.

Moreover, even if the winding misalignment occurs due to the winding of the metallized plastic film, stable characteristics can be obtained since the indirect oil conditions of the electrode film, auxiliary electrode, and electrode lead-out portion are hardly affected.

Although the above embodiment describes the case in which the electrode lead portion 15 is formed by metal spraying, even if the electrode lead portion is formed by immersing the end face of the capacitor element in molten solder that has been melted or vibrated, the solder and the electrode film will be removed. Excellent effects can be obtained through good contact with the

In addition, in the examples, the case where PP film was used was described, but other films such as tetrafluoroethylene, polyethylene terephthalate, polycarbonate, polyvinylisone fluoride, polybutylene terephthalate, polyethylene naphthalate, polyacetal, polysulfone, etc. Alternatively, similar effects can be obtained by combining two or more types.

[Brief explanation of the drawing]

FIG. 1 is a partial front cross-sectional view for explaining the state of the element end face of a conventional metallized plastic film capacitor, and FIG. 2 is a partial front cross-sectional view showing the state of the element end face of the metallized plastic film capacitor according to the present invention. , Fig. 3 is a characteristic distribution diagram showing the distribution of tan δ characteristics of the metallized plastic film container of the present invention and the conventional metallized plastic film container, and Fig. 4 is a characteristic distribution diagram showing the distribution of tan δ characteristics of the metallized plastic film container of the present invention before testing. Figure 5 is a characteristic distribution diagram showing the distribution of tan δ characteristics after the test, Figure 6 is a characteristic distribution diagram showing the distribution of tan δ characteristics of a conventional metallized plastic film capacitor before the test, and Figure 7 is a characteristic distribution diagram showing the distribution of tan δ characteristics before the test. Similarly, a characteristic distribution diagram showing the distribution of tan δ characteristics after the test, and FIG. 8 are explanatory diagrams showing cutting conditions for obtaining the metallized plastic film according to the present invention. 11...Polypropylene film, 12...
...Non-evaporated portion, 13...Electrode film, 14...
...Auxiliary electrode.

Claims (2)

[Scope of utility model registration request] (1) A metallized plastic film capacitor made of a capacitor element formed by winding a pair of plastic films each having an electrode film and a non-evaporated portion on its surface, and electrode extension portions of the electrode film and lead wires formed on both end faces of the capacitor element. 2. A metallized plastic film capacitor according to claim 1, further comprising an auxiliary electrode formed on the back surface of the non-evaporated portion. (2) The pair of plastic films is made of one or a combination of two or more of polypropylene, tetrafluoroethylene, polyethylene terephthalate, polycarbonate, polyvinylidene fluoride, polybutylene terephthalate, polyethylene naphthalate, polyacetal, and polysulfone. Scope of claims for utility model registration (1) characterized by
) Metallized plastic film capacitors as described in section 2.