JP2009021411A - Method of manufacturing metallized polypropylene film capacitor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a product which has a stable breakdown voltage by suppressing a beat sound when using a dry type metallized polypropylene film capacitor with a high voltage at high frequency. <P>SOLUTION: A device formed by winding a metallized polypropylene film is heat-pressed at a temperature of 80 to 120°C under a press pressure of 500×10<SP>4</SP>to 800×10<SP>4</SP>Pa, then metallized contact portions are formed on both winding end surfaces, and heat aging is performed at 80 to 120°C. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a dry-type metallized polypropylene film capacitor for electronic equipment using a metallized polypropylene film, and particularly relates to reduction of beat noise.

Metalized polypropylene film capacitors have a wide range of applications, especially in inverter circuits in the field of electronic equipment and automobiles, which are mainly used at high voltages and high frequencies. Had the problem of loud sounds.
In order to solve this problem, it has been proposed to prevent the beat sound generated from the capacitor element from leaking to the outside using a sound absorbing material (for example, Patent Document 1).
Also proposed is a method for reducing the beat noise by heating and pressure-molding a capacitor element in which a metallized film in which aluminum is vapor-deposited on a polyester film is wound from the top and bottom and from the left and right of the cross section (for example, patents). Reference 2).

JP 2005-93515 A JP 2000-12371 A

However, in the technology of Patent Document 1, it is necessary to examine the material, thickness, and the like of an appropriate sound absorbing material in order to prevent the beat sound generated from the capacitor element from leaking outside using the sound absorbing material. Not only is the structure complicated, but there is a disadvantage that the cost increases due to the use of a sound absorbing material. Therefore, it has been demanded to reduce beat noise with a simpler structure and manufacturing method.
Moreover, even when a capacitor element obtained by winding a metallized film in which aluminum is vapor-deposited on a polyester film is heated and pressure-molded from the top and bottom of the cross section and from the left and right directions by the method according to Patent Document 2, the roaring noise is sufficiently reduced. I couldn't make it. Therefore, instead of this, there has been a demand for a method for sufficiently reducing the beat sound.

The present invention solves the above-mentioned problem, and a polypropylene film provided with a metal vapor deposition film on one side is rolled and wound, or a polypropylene film provided with a metal vapor deposition film on both sides and a metal vapor deposition film on the surface. The present invention relates to a method of manufacturing a metallized polypropylene film capacitor having a capacitor element that is wound by overlapping with a polypropylene film that is not provided. The wound element is subjected to a temperature of 80 to 120 ° C. and a press pressure of 500 × 10 ^{4 to} 800 ×. After hot pressing at 10 ⁴ Pa, a metallicon part is formed on both winding end faces, and then heat aging is performed at 80 to 120 ° C.

In the metallized polypropylene film capacitor manufactured by the method of the present invention, the winding element is hot-pressed at a temperature of 80 to 120 ° C. and a pressing pressure of 500 × 10 ^{4 to} 800 × 10 ⁴ Pa, and then a metallicon part is formed. Heat aging at ˜120 ° C. can reduce beat noise when using high voltage and high frequency. Compared to the case of using a metallized film in which aluminum is vapor-deposited on a polyester film, the beat sound is reduced by 17 to 32. % Can be suppressed.
In addition, the breakdown voltage after the rated voltage and current application can be stabilized.

  In the production method of the present invention, the hot pressing time may be appropriately adjusted depending on the hot pressing temperature, the pressing pressure, the thickness of the polypropylene film, and the like. Generally, it is 3 to 20 minutes, preferably 5 to 15 minutes.

  In the production method of the present invention, thermal aging is performed by keeping the capacitor element at 80 to 120 ° C. in the air. For example, it can be performed in an air atmosphere using a thermostatic bath. The heat aging time is preferably 10 to 30 hours, and more preferably 15 to 25 hours.

  In the production method of the present invention, the preferred thickness of the polypropylene film is 3 to 12 μm.

In the present invention, the polypropylene film constituting the capacitor element, the deposited metal, the film thickness of the deposited metal, and the like may be the same as those of a normal dry metallized polypropylene film capacitor. Moreover, the other manufacturing process of a capacitor | condenser element and a capacitor | condenser may be the same as the manufacturing process of a normal dry-type metallized polypropylene film capacitor.
For example, after heat aging the capacitor element according to the present invention, a lead wire is welded by a normal method, and then put into a resin case and filled with a resin such as epoxy or urethane, or by dip coating, Metalized polypropylene film capacitors can be manufactured.

Hereinafter, the present invention will be described in detail by way of examples. The capacitors used in each example and comparative example were manufactured by the following method.
A metallized polypropylene film (deposited metal thickness: 0.015 μm, film resistance: 5Ω / □) deposited on one side of a 10 μm polypropylene film is wound and overlapped to form a capacitor element. After hot pressing to form a flat shape by heating and pressing from above and below for a minute, tin-based alloy was metallized on both winding end faces, and then heat aging was performed for 16 hours at a temperature described later. .
Thereafter, lead wires were welded to both metallicon electrodes, the capacitor element was dip-coated, and cured to produce a dry metallized polypropylene film capacitor (rated voltage: 630 V, capacitance: 10 μF).

[Examples 1-1 to 1-7]
According to the test conditions shown in Table 1, hot pressing was performed at a hot pressing temperature of 80, 100, and 120 ° C. and a hot pressing pressure of 500 × 10 ⁴ , 650 × 10 ⁴ , and 800 × 10 ⁴ Pa. The heat aging temperature was 80, 100, and 120 ° C.

(Comparative Examples 1-1 to 1-7)
Moreover, as a comparative example, hot pressing was performed at a hot pressing temperature of 70 and 130 ° C. and a hot pressing pressure of 400 × 10 ⁴ and 900 × 10 ⁴ Pa. The heat aging temperature was 70 and 130 ° C. And the thing without heat aging was also added for the effect confirmation by heat aging.

(Comparative Examples 2-1 to 2-14)
And as another comparative example, instead of the polypropylene film, for the polyester film, the metallized film capacitor in the same conditions as in Examples 1-1 to 1-7 and Comparative Examples 1-1 to 1-7. Fabricated and compared.

[performance test]
For the metallized polypropylene film capacitor and the metallized polyester film capacitor of the above-described Examples and Comparative Examples, the vibration of sound when 70 Vrms was applied at a frequency of 10, 20 kHz was measured.
In addition, about the measurement of the roaring sound, the microphone was measured 2 cm away from the metallized film capacitor. For the measurement, an integral sound level meter: LA4350 (manufactured by Ono Keiki Co., Ltd.) and an FFT analyzer: DS-2004 (manufactured by Ono Keiki Co., Ltd.) were used.
Table 1 shows the roaring sound and the destructive test result after 1000 hours of the rated voltage / current energization test. The measurement was performed one by one for each of the capacitors of each example or comparative example, and the average value was calculated. The evaluation was performed based on whether or not the beat sound at 10 kHz was less than 15 dB, the beat sound at 20 kHz was less than 20 dB, and the breakdown voltage was 3.0 kV or more.

From the results of Table 1 above, it can be seen that in Examples 1-1 to 1-7, the beat sound and breakdown voltage level are good. In Comparative Examples 1-1, 1-3, and 1-6, three conditions of a hot press temperature of 80 to 120 ° C., a hot press pressure of 500 × 10 ^{4 to} 800 × 10 ⁴ Pa, and a heat aging temperature of 80 to 120 ° C. Of these, when one of the values falls outside the lower limit, the winding of the capacitor element becomes loose, the beat noise becomes high, and the breakdown voltage after the energization test is reduced due to the influence of vibration, which indicates that the characteristics are not good.
In addition, from Comparative Examples 1-2, 1-4, and 1-7, even when one of the above three conditions (hot press temperature, hot press pressure, thermal aging temperature) deviates from the upper limit, the roaring noise increases and breaks down. It can be seen that the voltage decreases, which is not preferable. In particular, from Comparative Examples 1-2 and 1-4, when the hot press temperature or hot press pressure is outside the upper limit, the beat noise is improved compared to the case where the hot press temperature is outside the lower limit, but the breakdown voltage level is rather deteriorated. I understand.
Further, the condition of Comparative Example 1-5 without thermal aging is not preferable because the winding of the capacitor element becomes loose and voids are generated, and the beat noise becomes high and the breakdown voltage decreases.
And when the manufacturing method of the metallized polypropylene film capacitor | condenser by this invention is used, compared with Comparative Examples 2-1 to 2-14 using the metallized film which vapor-deposited aluminum on the polyester film, a roar is 17 Up to about 32% could be suppressed.

  The metallized polypropylene film capacitor of the present invention can be used with low roaring noise at high voltage and high frequency, such as an inverter circuit in the field of electronic equipment and automobiles, and can be widely used in consumer and industrial electrical equipment.

Claims (1)

A polypropylene film with a metal vapor-deposited film on one side is overlapped and wound, or a polypropylene film with a metal vapor-deposited film on both sides and a polypropylene film without a metal vapor-deposited film on the surface are superimposed. A method for producing a metallized polypropylene film capacitor having a wound capacitor element,
The wound element was hot-pressed at a temperature of 80 to 120 ° C. and a press pressure of 500 × 10 ^{4 to} 800 × 10 ⁴ Pa, and then a metallicon part was formed on both winding end faces, and then heated at 80 to 120 ° C. A method for producing a metallized polypropylene film capacitor, characterized by performing aging.