JP2009200378A - Composite metallized-film capacitor - Google Patents

Abstract

An object of the present invention is to provide a composite metallized film capacitor in which two types of elements having different functions are wound on the same axis to improve heat dissipation and moisture resistance.
A first element 1 in which a metallized film is wound as a pair, an insulating film 2 wound around the outer periphery of the first element 1, and a first element 1 on the insulating film 2 Similarly, the second element 3 is wound, and the first element 1 and the metallicon electrode independently formed on both end faces of the second element 3, and the thickness of the dielectric film of the first element 1 By using the second element 3 having a thick dielectric film, two types of elements having different functions on the same axis are independently formed, so that the second element 3 is located on the outer peripheral side while being reduced in size. Heat dissipation and moisture resistance can be improved by using a film having a thickness of the dielectric film of the element 3 larger than that of the dielectric film of the first element 1.
[Selection] Figure 1

Description

  The present invention is used in various electronic devices, electrical devices, industrial devices, automobiles, etc., and in particular, among metallized film capacitors that are optimal for smoothing, filtering, and snubbing of inverter circuits for driving motors of hybrid vehicles. The present invention relates to a composite metallized film capacitor in which two types of metallized film capacitors having different values are formed on the same axis.

  In recent years, from the viewpoint of environmental protection, all electric devices are controlled by inverter circuits, and energy saving and high efficiency are being promoted. In particular, in the automobile industry, hybrid vehicles (hereinafter referred to as HEVs) that run on electric motors and engines have been introduced into the market, and the development of technologies relating to energy saving and high efficiency has been activated, which is friendly to the global environment.

  Since such a HEV electric motor has a high operating voltage range of several hundred volts, a metallized film capacitor having high withstand voltage and low loss electric characteristics as a capacitor used in connection with such an electric motor. In addition, the trend of adopting metalized film capacitors with a very long life is conspicuous due to the demand for maintenance-free in the market.

  Such metallized film capacitors are roughly classified into those generally using a metal foil as an electrode and those using a deposited metal provided on a dielectric film as an electrode. Among these, metallized film capacitors that use vapor-deposited metal as an electrode (hereinafter referred to as metal vapor-deposited electrode) have a smaller volume occupied by the electrode compared to that of metal foil and can be reduced in size and weight. High reliability in dielectric breakdown due to recovery function (capacity of metal evaporated electrode around the defective part evaporates and scatters and insulates when the short-circuit occurs in the defective part) Therefore, it has been widely used conventionally.

  FIG. 6 is a schematic cross-sectional view showing the structure of a conventional metallized film capacitor of this type, and FIG. 7 is a schematic diagram of a first metallized film used in this metallized film capacitor. 11 and 11a are dielectric films, 12 and 12a are metal vapor deposition electrodes formed on the dielectric films 11 and 11a, and 13 and 13a are low metal films formed by thickening such metal vapor deposition electrodes. The resistance part 14 is a fuse part that divides a divided electrode, which will be described later, when micro-breakdown occurs, 15 and 15a are margin parts where metal deposition is not performed, 15b is the width of the margin parts 15 and 15a, and 16 is connected by the fuse part 14. An electrode partition portion for forming a divided electrode, 17 is a width of the low resistance portions 13 and 13a, 18 is a micro block partitioned into divided electrodes by the electrode partition portion 16, 19 First metal films, 20 shows a second metallized film.

  Then, the first metallized film 19 and the second metallized film 20 thus configured are opposed to the metal vapor-deposited electrodes 12 and 12a through the dielectric films 11 and 11a as shown in FIG. Thus, a metallized film capacitor was constituted by forming an element by winding and forming a metallicon electrode (not shown) by metal spraying on both end faces of the element.

  In addition, the said 2nd metallized film 20 is the same as the 1st metallized film 19, and the metal vapor deposition electrode shape which has the micro block 18 and the fuse part 14, or the metal vapor deposition which does not have the micro block 18 and the fuse part 14 Any of the electrode shapes may be used.

  The conventional metalized film capacitor configured as described above is capable of improving the operability of the self-protection mechanism formed by connecting the micro blocks 18 formed of the divided electrodes by the fuse portion 14 ( Patent Document 1).

  FIG. 8 is a cross-sectional view showing the structure of a composite metallized film capacitor divided into a plurality of capacitor elements by winding an insulating sheet coaxially in one element. Reference numeral 21 denotes a capacitor element, 22 denotes a capacitor element portion, 23 denotes an insulating layer, 24 denotes a metallicon layer, 25 denotes a metallicon removal portion, and 26 denotes an electrode extraction portion.

The conventional composite metallized film capacitor configured as described above can be miniaturized by forming two metallized film capacitors having different functions on the same axis (Patent Document 2).
JP 2005-85870 A Japanese Utility Model Publication No. 55-173132

  However, when the above conventional metallized film capacitor is molded in a case using a mold resin and used for HEV, it is used for the purpose of smoothing the AC component of the DC power supply. Since the current is increased, the heat generation of the capacitor is increased and the thermal margin is reduced, so that there is a problem that high heat dissipation performance is required.

  In addition, it is inevitable that external moisture or air enters from the interface between the metalized film capacitor and the mold resin, and moisture or air enters the inside of the capacitor element, which may deteriorate the performance and quality of the metalized film capacitor. There is also a problem that high moisture resistance is required because of the risk of incurring.

  Therefore, in the composite metallized film capacitor that is miniaturized by forming two metallized film capacitors having different functions on the same axis, in addition to reducing the size and weight and reducing the cost, high heat dissipation performance and moisture resistance performance are achieved. It had a problem of being required.

  An object of the present invention is to solve such a conventional problem, and to provide a composite metallized film capacitor capable of exhibiting high heat dissipation performance and moisture resistance in addition to reduction in size and weight and cost. Is.

  In order to solve the above-mentioned problems, the present invention forms a pair of metallized films in which metal vapor-deposited electrodes are formed on a dielectric film, and the metal vapor-deposited electrodes are overlapped and wound so as to face each other through the dielectric film. A first element; an insulating film wound around the outer periphery of the first element; a second element wound on the insulating film in the same manner as the first element; and the first element. In addition, it is made up of a metallicon electrode independently formed on both end faces of the second element, and is coaxial by using a dielectric film of the second element that is thicker than the dielectric film of the first element. Two types of elements having different functions are formed independently on each other.

  As described above, the composite metallized film capacitor according to the present invention is reduced in size by forming two metallized film capacitors having different functions on the same axis, and the dielectric of the second element located on the outer peripheral side. By using a film having a thickness greater than that of the dielectric film of the first element, the effect of improving the heat dissipation performance and moisture resistance performance can be obtained.

(Embodiment 1)
In the following, the first and third aspects of the present invention will be described with reference to the first embodiment.

  1 is a perspective view showing a configuration of a composite metallized film capacitor according to Embodiment 1 of the present invention, FIG. 2 is a cross-sectional view thereof, FIG. 3 is a circuit diagram thereof, and in FIGS. This first element 1 uses a polypropylene film (hereinafter referred to as a PP film) having a thickness of 3.0 μm and a width of 50 mm as a dielectric film, on one or both sides of the PP film. A pair of metallized films (not shown) on which a metal vapor deposition electrode having a resistance value of 20Ω / □ is formed and wound in a state where the metal vapor deposition electrodes oppose each other through a PP film, so that the capacitance is 150 μF. The smoothing capacitor is constructed.

  Reference numeral 2 denotes an insulating film wound around the outer periphery of the first element 1. In this embodiment, a PP film having a thickness of 10 μm and a width of 55 mm is used and wound for 7 turns.

  3 is a second element. Like the first element 1, the second element 3 uses a PP film having a thickness of 12 μm and a width of 50 mm as a dielectric film. A pair of metallized films (not shown) having a metal vapor-deposited electrode having a resistance value of 2Ω / □ on both surfaces is wound on the insulating film 2 with the metal vapor-deposited electrodes facing each other through a PP film. Thus, a snubber capacitor having a capacitance of 1 μF is configured.

  Reference numerals 1a, 1b, 3a, and 3b are a P-electrode and an N-electrode made of metallicon. These electrodes are independent by spraying zinc on both end faces of the first element 1 and the second element 3, respectively. Thus, the P-pole electrode 1a and the N-pole electrode 1b of the first element 1, and the P-pole electrode 3a and the N-pole electrode 3b of the second element 3, respectively, are provided. Between the P-pole electrode 1a of the first element 1 and the P-pole electrode 3a of the second element 3, and between the N-pole electrode 1b of the first element 1 and the N-pole electrode 3b of the second element 3, respectively. Therefore, the individual electrodes are all in an independent state.

  The composite metallized film capacitor according to this embodiment configured as described above can be reduced in size by forming two metallized film capacitors having different functions for smoothing and snubber on the same axis of one element. There is an extraordinary effect that the cost can be reduced.

  Further, the thickness of the dielectric film of the second element 3 located on the outer peripheral side is thicker than the thickness of the dielectric film of the first element 1, and the resistance of the second element 3 is higher than that of the first element 1. It is possible to improve the heat dissipation performance and the moisture resistance performance by the configuration in which the capacitance is small (the thickness of the metal deposition electrode is thick) and the capacitance of the second element 3 is smaller than the capacitance of the first element 1. (Table 1) shows the results of a moisture resistance test (85 ° C., 85%) conducted for the purpose of confirming such effects, together with comparative examples.

  In the moisture resistance current test, the composite metallized film capacitor according to the present embodiment is housed in a resin case having a thickness of 2 mm, molded with an epoxy resin so that the resin thickness becomes 2 mm, and then the first element 1 Apply a 0.1 Arms / μF @ 20 kHz sine wave to the smoothing capacitor, and a 10 Arms / μF @ 10 kHz sine wave to the snubber capacitor, which is the second element 3. , And the capacitance change rate after 2000 hours of the smoothing capacitor as the first element 1 was measured.

  Further, Comparative Example 1 is configured by independently preparing a smoothing capacitor as the first element 1 and a snubber capacitor as the second element 3, respectively. 2 is configured by winding with the snubber capacitor as the second element 3 inside and the smoothing capacitor as the first element 1 outside.

  As is clear from (Table 1), the composite metallized film capacitor according to the present embodiment is excellent in heat dissipation because the temperature rise of both the first element 1 and the second element 3 is small compared to the comparative example. In addition, it can be seen that the first element 1 has a low capacitance change rate, and thus has excellent moisture resistance.

  The types and thicknesses of the dielectric films of the first element 1 and the second element 3 described in the present embodiment, the resistance value, the capacitance, and the types and thicknesses of the insulating film 2 are shown as an example. However, the present invention is not limited to these examples.

(Embodiment 2)
The second aspect of the present invention will be described below with reference to the second embodiment.

  In the present embodiment, the configuration of the metallicon electrode of the composite metallized film capacitor described in Embodiment 1 with reference to FIGS. 1 to 3 is partially different, and other configurations are implemented. Therefore, the same parts are denoted by the same reference numerals and detailed description thereof will be omitted, and only different parts will be described in detail below with reference to the drawings.

  4 is a cross-sectional view showing a configuration of a composite metallized film capacitor according to Embodiment 2 of the present invention, FIG. 5 is a circuit diagram thereof, and in FIGS. 4 and 5, 1 is the first element, 2 is Insulating film, 3 is the second element, 1a is the P pole electrode of the first element 1, 3a is the P pole electrode of the second element 3, and 1c is the N pole electrode and the second element of the first element 1. It is a common N pole electrode which connected the 3 N pole electrode in the conduction | electrical_connection state.

  The composite metallized film capacitor according to the present embodiment configured as described above has an effect obtained by the composite metallized film capacitor according to the first embodiment, in addition to the N pole electrodes of two types of elements having different functions. Are connected by the common N-pole electrode 1c, so that the connection with the external lead terminal is simplified, and there is an extraordinary effect that the cost and performance can be improved. Table 1 shows the results of the moisture resistance test (85 ° C., 85%) performed in step 1 and the comparative example.

  As is clear from (Table 1), the composite metallized film capacitor according to the present embodiment is excellent in heat dissipation because the temperature rise of both the first element 1 and the second element 3 is small compared to the comparative example. In addition, it can be seen that the first element 1 has a low capacitance change rate, and thus has excellent moisture resistance.

  The composite metallized film capacitor according to the present invention has the effect of reducing the size and weight and reducing the cost, and being excellent in heat dissipation and moisture resistance, and particularly for automobiles that require a reduction in size and weight and high reliability. It is useful as a field capacitor.

The perspective view which showed the structure of the composite type metallized film capacitor by Embodiment 1 of this invention Cross section Same circuit diagram Sectional drawing which showed the structure of the composite type metallized film capacitor by Embodiment 2 of this invention Same circuit diagram Cross-sectional schematic diagram showing the structure of a conventional metallized film capacitor Schematic diagram of the first metallized film used in the metallized film capacitor Sectional view showing the structure of a conventional composite metallized film capacitor

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st element 1a P pole electrode of 1st element 1b N pole electrode of 1st element 1c Common N pole electrode 2 Insulating film 3 2nd element 3a P pole electrode of 2nd element 3b 2nd element N pole electrode

Claims (5)

A first element in which a metallized film having a metal vapor-deposited electrode formed on a dielectric film is paired, and the metal vapor-deposited electrode is overlapped and wound so as to face each other through the dielectric film, and the first element An insulating film wound around the outer periphery of the substrate, a second element wound on the insulating film in the same manner as the first element, and metal spraying on both end faces of the first element and the second element. Each having a metallicon electrode formed independently, and the function of the second element is different from that of the first element by using a thicker dielectric film than the first element. A composite metallized film capacitor in which two types of elements are formed independently. The composite metallized film capacitor according to claim 1, wherein the resistance of the second element is smaller than the resistance of the first element. The composite metallized film capacitor according to claim 1, wherein the capacitance of the second element is smaller than the capacitance of the first element. 2. The composite metallized film capacitor according to claim 1, wherein one metallicon electrode of metallicon electrodes independently formed on both end faces of the first element and the second element is connected with the same polarity. The composite metallized film capacitor according to claim 1, wherein the first element is for smoothing the inverter circuit, and the second element is for the snubber.

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