JPH02138719A - Capacitor - Google Patents

Abstract

PURPOSE:To prevent the capacity reduction and the deterioration in insulating properties by the life test, etc., from occurring by a method wherein the title capacitor is manufactured by winding around metallized plastic films provided with a zinc spray coated film at respective specified film resistance values as well as an aluminum evaporated film. CONSTITUTION:The title capacitor is manufactured by winding around a metallized plastic film 12 provided with a zinc spray coated layer 11 to be one metallized electrode with the film resistance values at respective wound ends of 2-10OMEGA per unit space at the thick side end part 11a and 10-50OMEGA at the other part as well as another metallized plastic film 14 provided with an aluminum evaporated layer 13 to be the other metallized electrode. Through these procedures, the capacity reduction and the deterioration in insulation resistance between mutual terminals by the life test can be restrained and prevented from occurring, thereby enabling the title capacitor of long life and high reliability to be manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a container formed by winding a metallized plastic film.

BACKGROUND OF THE INVENTION Aluminum or zinc is generally used as the vapor-deposited metal (metallized electrode) for metalized plastic films. Furthermore, the two opposing metallized electrodes used the same metal, such as aluminum or zinc.

There have been problems such as erosion and a decrease in capacitance due to erosion, and a decrease in insulation resistance between terminals due to incomplete self-healing action.

Means for Solving the Problems In order to solve the above problems, in the capacitor of the present invention, one of the metallized electrodes is made of zinc, and the end of the metallized electrode on the electrode extraction side is made thicker than the other part. The material of the other metallized electrode is aluminum.

Effect: The above means suppresses a decrease in capacity during a life test and a decrease in insulation resistance between terminals, thereby improving reliability.

EXAMPLES Hereinafter, examples of the present invention will be described with reference to the accompanying drawings.

In FIG. 1, reference numeral 11 denotes a zinc vapor-deposited film deposited on the film 12, and the film thickness at the electrode lead-out side end 11a is increased (
The remaining portion 11b has a thinner film thickness (membrane resistance value 10 to 60 Ω/hole). Reference numeral 13 denotes an aluminum vapor-deposited film deposited on the film 14, and the film resistance value was set to 3010.

A 60 μF capacitor was prepared using a single-sided vapor deposited polypropylene (hereinafter referred to as PP) film having a thickness of 6 μm as a sample. comparison hb 7
/ Samples were prepared using evaporated metals of reminium and zinc. The film resistance value of each vapor-deposited metal was set to sQ1. A continuous durability test was conducted as a life test. The test conditions were to apply AC 300 V in a thermostatic chamber with an oC atmosphere, and to examine the rate of change in capacitance and the change in insulation resistance between terminals compared to before the test (initial value). The results are shown in FIGS. 2 and 3. From this test result, the rate of change in capacity relative to the initial value (
(see Figure 2), the sample in which 7-luminium was used as the vapor-deposited metal of the two electrodes showed a large decrease. In addition, it can be seen from the change in insulation resistance between terminals (refer to Figure 3) that the sample in which zinc was used as the vapor-deposited metal of the two electrodes was significantly deteriorated.

In addition, the same test was conducted with a capacitor having the same specifications as described above by changing the film resistance value of the zinc evaporated film other than the electrode lead-out side end, and the relationship between the supply edge resistance value and tan δ for 1000 hours is shown in Figure 7. Shown below.

As can be seen from FIG. 7, when the resistance value of the deposited zinc film is low, it affects the change in the insulation resistance value, and when the film resistance value exceeds a certain value, it affects the tan δ of the capacitor.

Next, we created a capacitor with a safety function by dividing the evaporated M electrode on the aluminum evaporated metal side into multiple pieces and attempted a reliability test using samples other than those in which the evaporated metal of both electrodes was zinc. is. In FIG. 4, the aluminum vapor deposited film 16 was divided, the ratio of the width n of the joint between the electrode part and the metal sprayed layer to the division width m was set to 10%, and the dielectric structure was the same as in FIG. An intermittent durability test was conducted as a life test.

The test conditions were ACs in a constant temperature chamber with an atmosphere of 100℃.
Current was applied intermittently for 2 seconds at soV and no current was applied for 2 seconds, and the rate of change in capacity relative to before the test (initial value) was examined. The results are shown in FIG. Table 1 also shows the safety test results.

Table 1 The test results also show that the capacity reduction of the present invention is suppressed, and even with the addition of the safety function, the non-joint fusing effect between the electrode part of the vapor deposited film and the metal sprayed layer (hereinafter referred to as metallicon) is excessive. It can be seen that this does not occur, and that it has both safety functions and practical capacitor life, and can withstand long-term use.

In this example, of the two vapor-deposited metals, the film thickness of the electrode 11 on the electrode lead-out side of the zinc vapor-deposited metal and the electrical contact with the metallicon were investigated. As a test, a forced short-circuit charge/discharge test was conducted.

Figure 6 shows the membrane resistance value and t at 50th cycle at DC300V.
The relationship between andδ is shown.

As is clear from FIG. 6, it can be seen that by setting the film thickness of the zinc-deposited film at the electrode lead-out side end to 2 to 10 Ω/hole, the strength of the metallicon joint is improved. When the film resistance value of the zinc evaporation was lower than 20/port, the film was thermally damaged during the evaporation process, thermal deformation occurred, and the evaporation yield decreased. From this, 2Ω/mouth to 1o/mouth is appropriate.

Effects of the Invention As described above, by having each of the superior points of vapor-deposited metal aluminum and zinc, it is possible to suppress the decrease in capacity and the deterioration of the insulation resistance between terminals in life tests, etc., resulting in a long life. , a highly reliable capacitor can be realized.

[Brief Description of the Drawings] Figure 1A is an exploded perspective view of a capacitor showing an embodiment of the present invention, Figure 1B is a sectional view of the same capacitor, and Figure 2 shows the capacitance change of the same capacitor during testing. 3 is a characteristic diagram showing the change in insulation resistance between terminals during testing of the same capacitor, FIG. 4A is an exploded perspective view of a capacitor showing another embodiment of the present invention, and FIG. 4B is the same. A developed plan view of the capacitor, Figure 5 is a characteristic diagram showing the capacitance change during a life test of the same capacitor, and Figure 6 is a characteristic diagram showing the relationship between the Zn vapor deposited film resistance value and tan δ at the end of the electrode extraction side of the same capacitor. , Figure 7 shows the film resistance value of the part other than the electrode lead-out side end on the vapor-deposited metal zinc side, the change in insulation resistance between terminals during life test, and tan
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Claims (3)

[Claims] (1) A metallized plastic film is wound, and a lead-out metal sprayed layer is provided on the end surface of the winding. The material of the metallized electrode of one pole is zinc, and the end of the metallized electrode on the lead-out side of the other pole is made of zinc. A capacitor characterized in that the material of the metallized electrode of the other pole, which is formed thicker than the metallized electrode of the one pole and is opposed to the metallized electrode of the one pole, is made of aluminum. (2) A claim characterized in that the metallized electrode made of zinc has a membrane resistance value of 2 to 10 Ω/□ at the electrode extraction side end, and a membrane resistance value of 10 to 50 Ω/□ in other parts. The capacitor according to item 1. (3) The capacitor according to claim 1 or 2, wherein the safety mechanism is provided by dividing a metallized electrode made of aluminum into a plurality of parts.