JP2010016160A - Metalized film capacitor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve an anti-thermal shock property and resistance to vibration under use conditions of a wide temperature range in a metalized film capacitor having a case of which the upper end face is opened, one or a plurality of capacitor elements stored in the case that use metalized films, and have metallicon electrodes at both ends, an external leading terminal connected to the metallicon electrode, and a resin composition that is filled in the case and buried with the capacitor element. <P>SOLUTION: The capacitor element is buried by the resin composition filled in the case. The metallicon electrode and the external leading terminal of the metallicon electrode portion are coated with removers. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a metallized film capacitor in which one or more capacitor elements using a metallized film are housed in a case having an opening and filled with a resin composition.

  In recent years, reliability required for metallized film capacitors has been increasing, and similar reliability is required even in severe use environments.

  Conventionally, a capacitor element using a metallized film is housed in a case with an opening, and a metallized film capacitor filled with a resin composition is formed by winding or laminating two metallized films, After winding or laminating a metal such as zinc on the wound or laminated end faces to bring out metallicon, a capacitor element is manufactured by performing a temperature treatment called heat treatment as necessary. Next, external terminals were connected to the electrodes at both ends of the capacitor element or the plurality of capacitor elements, housed in a resin case, and then filled with a resin composition.

  In recent years, an inverter circuit suitable for energy saving and high efficiency has been adopted from the consideration of the environment. However, since the working voltage is high, there is a tendency to use a film capacitor among the capacitors. In particular, in applications such as on-vehicle moving bodies, conditions for use such as moisture resistance and vibration resistance are required over a long period of time in a wide temperature range.

As a technique for improving the durability of a metallized film capacitor housed in such a case, Patent Document 1 describes that the resin composition filled in the case is made into a layer of an epoxy resin composition, and the external lead terminal is most derived. A technique in which the linear expansion coefficient of the upper layer is minimized is disclosed. This technology makes the linear expansion coefficient of the uppermost layer of the epoxy resin composition closer to the linear expansion coefficient of the external lead terminal, which is a metal, and prevents cracks from occurring in the resin composition of the upper layer. Techniques to do this are disclosed.
JP 2006-147687 A

  However, as described above, the technology for bringing the linear expansion coefficient of another substance closer to the linear expansion coefficient of a certain substance uses a metallized film mainly made of resin, and a metallicon electrode made of metal on both ends and an external lead electrode. However, it is not a solution for a portion where different linear expansion coefficients are mixed, such as a metallicon electrode portion where a resin composition filled on the surface is present.

  An object of the present invention is to eliminate problems that occur in the metallicon electrode portion of a metallized film capacitor housed in a case, and to stabilize moisture resistance and vibration resistance over a long period of time under a wide temperature range of use conditions.

As a means for solving the problems, the present invention includes a case having an open upper end surface, and one or more capacitor elements housed in the case and using metallized films and provided with metallicon electrodes at both ends. And an external lead terminal connected to the metallicon electrode, and a resin composition filled in the case to bury the capacitor element, the metallicon electrode being covered with a release material.
Further, the metallicon electrode and the external lead terminal of the metallicon electrode portion are covered with a release material.

ADVANTAGE OF THE INVENTION According to this invention, the malfunction which generate | occur | produces in the metallicon part of a metallized film capacitor with a case is eliminated, and the metallized film capacitor which improves a thermal shock and vibration resistance on the use conditions of a wide temperature range can be provided.

  The case of the present invention is a container generally used for a film capacitor having an open upper end surface, and is made of plastic or metal. In the case of plastic, for example, it is made of a resin such as polyethylene terephthalate, polybutylene terephthalate, polycarbonate, or polyphenylene sulfide. If it is a metal, it will consist of aluminum, magnesium, iron, stainless steel, copper, etc., for example.

  Capacitor element of the present invention, the film surface of polyethylene terephthalate, polypropylene, etc., a metallized film vapor-deposited metal such as aluminum, copper, zinc, etc. A metallized electrode is provided by spraying a metal such as copper or aluminum. The cross-sectional shape is circular when it is wound, flat when it is crushed, and quadrilateral when it is stacked, but the side of the flat or square is flat and the storage efficiency and heat dissipation are improved.

  As the metallicon electrode of the present invention, those generally used for film capacitors can be used, which are made of metal or alloy such as copper, zinc, aluminum, tin, solder, etc., and formed by thermal spraying. In some cases, the surface of the electrode may be plated.

  The external lead terminal of the present invention is generally used for a film capacitor and has a rod shape or a plate shape. The material is, for example, a metal or alloy such as copper, aluminum, iron, nickel, stainless steel, phosphor bronze, etc. In some cases, the surface is plated with tin, solder, or the like. The plate thickness can be used without particular limitation from about 0.1 mm to 2.0 mm.

  The resin composition of the present invention is a material generally used for filling a film capacitor, and is obtained by mixing a filler or the like with a resin such as an epoxy resin or a urethane resin. As the filler, hydroxides such as silicon, titanium, aluminum, calcium, zirconium, and magnesium, oxides, carbides, nitrides, and composites thereof can be used. If necessary, a flame retardant and an antioxidant may be added.

The release material of the present invention is a material that undergoes displacement deformation due to peeling of the release material interface or internal destruction of the release material, for example, a resin such as silicone resin, fluorine-containing resin, fluorine-containing coupling material, silicone rubber, silicone gel, In addition to fluorine-containing rubber and fluorine-containing gel, silicone oil and resin containing fluorine-containing oil can be used.
Moreover, the shape can be used without limitation, such as a liquid, a solidified liquid, or a sheet. A sheet-like material is easy to install if an adhesive or a fusing agent is laminated on one side to be adhered.
The places where the release material is provided are provided on the surface of the metallicon electrode at both ends of the capacitor element, the external lead terminal part of the metallicon electrode part, and the metallicon electrode peripheral part. Although it is preferable to provide the entire surface of each of these portions, it may be partially missing. Further, the external lead terminal portion of the metallicon electrode portion and the peripheral portion of the metallicon electrode may be omitted as necessary.
The release material can be applied by spraying, brushing, or dipping the end face, or by wrapping a mask film around the side surface of the film between the metallicon electrodes or the external lead terminal, etc. The film for masking may be removed after immersion.
For brush coating, only the metallicon electrode or only the external lead terminal part in contact with the metallicon electrode and the metallicon electrode can be covered with a release material, and the remaining external lead terminal part and the resin composition can be sufficiently adhered. it can. Moreover, in order to coat the metallicon electrode and the external lead terminal on the upper surface portion of the metallicon electrode portion with a release material, spraying or end face dipping can be employed, and the coating workability can be improved.
The coating thickness of the release material is within a range that does not hinder the miniaturization of the capacitor. Specifically, the thickness is about 1 μm to 200 μm, preferably about 2 μm to 100 μm.

According to the present invention, the capacitor element itself housed in the case is fixed by the resin composition that is filled and buried in the case, so that it is difficult to resonate with external vibration, and the amplitude is larger than external vibration. There is nothing. In addition, since the metallicon electrode portions at both ends are covered with a release material, the stress generated due to the difference in thermal expansion coefficient generated at the interface with the resin composition filled and buried in the case is subjected to interface peeling or It can be mitigated by displacement deformation due to destruction inside the release material. Therefore, it is possible to prevent occurrence of cracks in the metallicon electrode and disconnection at the metallicon portion corresponding to the use conditions in a wide temperature range. Also, stress that affects the electrical connection between the metallicon electrode and the metallized film is less likely to occur.

Hereinafter, the present invention will be described based on embodiments shown in the drawings.
FIG. 1 shows a schematic cross-sectional view (a) and a schematic vertical cross-sectional view (b) of a metallized film capacitor according to the present invention. FIG. 1 shows that a capacitor element using a metallized film housed in a case with an open upper end surface is filled with resin and buried, and the metallicon electrode surface at both ends of the capacitor element and the metallicon of the external lead terminal The example which coat | covered the electrode connection part and the metallicon electrode peripheral part with the peeling material is shown.
Reference numeral 1 denotes a case opened upward, which is made of metal or plastic.
Reference numeral 2 denotes a capacitor element. Two metallized films, that is, two thin strip-like insulating films (usually polyester films) in which aluminum or the like is deposited on one side to form a metal electrode are overlapped and wound a predetermined number of times. The oblong columnar body is flattened, and the metallicon electrodes 3 formed by thermal spraying of metal or alloy are provided on both end faces thereof. In FIG. 1, two capacitor elements 2 are arranged in parallel.
Reference numeral 4 denotes an external lead terminal, one end of which is connected to the metallicon electrode 3 and the other end is connected to the outside.
5 is a release material, which is provided on the surface of the metallicon electrode 3 at both ends of the capacitor element 2, the external lead terminal 4 portion of the metallicon electrode 3 portion, and the peripheral portion of the metallicon electrode 3.
6 is a resin composition in which a filler is added to a resin such as an epoxy resin or a urethane resin.

  FIG. 2 shows a cross-sectional schematic view of another metallized film capacitor according to the present invention. An example is shown in which the surface of the metallicon electrode 3 at both ends of the capacitor element 2, the external lead terminal 4 portion of the metallicon electrode 3 portion, and the peripheral portion of the metallicon electrode 3 are covered with a release material 5.

FIG. 3 shows a cross-sectional schematic view of another metallized film capacitor according to the present invention.
The case where the adhesive tape as the release material 5 is attached to the surface of the metallicon electrode 3 and the external lead terminal 4 of the metallicon electrode 3 is shown.

Example 1
Aluminum is vapor-deposited on one side, two thin strip-like insulating polyester films with metal electrodes are stacked and wound, flattened into an oval column, copper on both ends, and tin sprayed on the surface A capacitor element was obtained by providing a metallicon electrode formed by: Next, two capacitor elements were arranged in parallel, and one end of a copper plate plated with tin processed for an external lead electrode was joined to the surface of the metallicon electrode portion by welding. Next, a silicone resin as a release material was provided with a film thickness of about 5 μm to 20 μm as a release material on the surface of the metallicon electrode, the metallicon electrode connecting portion of the external lead terminal, and the peripheral portion of the metallicon electrode. Next, it was housed in a case made of a polyphenylene sulfide resin and filled with a resin composition in which an epoxy resin was mixed with a filler such as magnesium oxide.

(Example 2)
Using the silicone resin of Example 1 as a release material, with a spray method, the metallicon electrode surface of the metallicon electrode surface, the external lead terminal portion of the metallicon electrode portion and the metallicon electrode peripheral portion with a film thickness of about 5 μm to 20 μm It was created in the same manner as Example 1 except that it was provided.

(Example 3)
It was produced in the same manner as in Example 1 except that a 50 μm-thick fluorine-containing resin adhesive tape was applied as a release material from the side surface to the metallicon electrode surface and the external lead terminal portion of the metallicon electrode portion.

(Comparative Example 1)
A silicone resin of Example 1 was used, and the same as Example 1 was made except that the entire capacitor element was immersed in this resin.

The above examples and comparative examples, and those using no release material as conventional example 1, heat cycle test, high temperature and high humidity test, vibration test were carried out at each n = 10, increase in loss rate before and after the test The result of Table 1 was obtained from the average value.
As a test condition, the heat cycle test is 1000 cycles at −40 ° C. to 105 ° C. High temperature and high humidity test is 85 ° C, 85%, 1000 hours. In the vibration test, the front, rear, left, right, and upper directions were set to 8 G of 5 to 200 Hz in 5 hours.
From the above test, the example of the present invention was more stable against thermal fluctuation and vibration than the comparative example in which the release material was provided on the entire capacitor element and the conventional example having no release material.

The cross-sectional schematic and longitudinal cross-sectional schematic of the metallized film capacitor which concern on this invention are shown. Figure 2 shows a cross-sectional schematic view of another metallized film capacitor according to the present invention. Figure 2 shows a cross-sectional schematic view of another metallized film capacitor according to the present invention.

Explanation of symbols

1 Case 2 Capacitor Element 3 Metallicon Electrode 4 External Lead Terminal 5 Release Material 6 Resin Composition

Claims (2)

  A case having an open upper end surface, a single or a plurality of capacitor elements provided with metallized electrodes on both ends using a metallized film, and an external lead terminal connected to the metallized electrode, housed in the case; A metallized film capacitor comprising a resin composition filled in the case and embedded in a capacitor element, wherein the metallicon electrode is covered with a release material.   The metallized film capacitor according to claim 1, wherein a connecting portion between the metallicon electrode and the metallicon electrode of the external lead terminal is covered with a release material.

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