JP7301975B2 - Film capacitor - Google Patents

Description

The present invention relates to film capacitors.

As one type of capacitor, there is a film capacitor having a structure in which a flexible resin film is used as a dielectric, and a first counter electrode and a second counter electrode are arranged to face each other with the resin film interposed therebetween. Such a film capacitor is produced, for example, by winding or laminating a resin film on which a first counter electrode is formed and a resin film on which a second counter electrode is formed (see, for example, Patent Documents 1 and 2 reference).

Patent Document 1 discloses a capacitor element formed by superimposing metallized films and forming metal electrodes on both ends in the axial direction, and external extraction terminals on the anode side and the cathode side connected to the metal electrodes of the capacitor element. , wherein the first metallized film has a first electrode pattern in which the metal deposition electrodes are divided and connected to each other through a fuse portion, and the anode side The second metallized film is connected to an external lead-out terminal, while the second metallized film is in a non-divided state in which the metallized electrode remains continuous or in a state divided by an area larger than the metallized electrode of the first metallized film. having a film resistance value greater than the film resistance value of the metal-evaporated electrode of the first metallized film and connected to the cathode-side external extraction terminal. is disclosed.

Patent Document 2 discloses a film capacitor element having a first vapor deposition electrode, a second vapor deposition electrode, and at least two dielectric films, and metallikon portions are formed on both sides of the film capacitor element. and a fuse connecting the divided electrodes in parallel. A metallized film capacitor is disclosed that is elevated above the evaporated electrodes.

JP 2017-191823 A JP-A-2004-95604

In Patent Document 1, a split electrode having a fuse portion is connected to the anode side, and the film resistance value thereof is made lower than the film resistance value of a non-split electrode having no fuse portion, thereby improving withstand voltage performance. It discloses that

However, in the film capacitor described in Patent Document 1, since the split electrode having the fuse part is arranged on the anode side, the anodization reaction proceeds in a high temperature environment exceeding 125° C., and the anode side The film resistance value of the arranged split electrodes will increase. If the film resistance value of the split electrodes increases, there is a problem that a current required to operate the fuses in the vapor deposition pattern cannot be supplied, resulting in a short failure.

Further, Patent Document 2 discloses that the self-recovery performance of the non-split electrodes can be improved by making the film resistance of the non-split electrodes higher than the film resistance of the split electrodes. However, Patent Document 2 does not specify whether the split electrodes and the non-split electrodes are arranged on the anode or the cathode.
However, in Patent Document 2, if the undivided electrode with high film resistance is arranged on the anode side, an anodization reaction proceeds in the undivided electrode with originally high film resistance, resulting in a further increase in film resistance. On the other hand, when a non-divided electrode with high film resistance is arranged on the cathode side, the same problem as in Patent Document 1 arises.

Under these circumstances, there has been a demand for a film capacitor whose fuse operability is less likely to deteriorate even in a high temperature environment exceeding 125°C.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems, and to provide a film capacitor whose fuse operability is less likely to deteriorate even in a high temperature environment exceeding 125.degree.

A film capacitor of the present invention has a first main surface and a second main surface, a first dielectric film made of resin, and a first dielectric film facing the first main surface of the first dielectric film. an electrode layer, a second electrode layer facing the second main surface of the first dielectric film, and the first dielectric film interposed between the first electrode layer or the second electrode layer a second dielectric film made of resin and having a third main surface and a fourth main surface, and a first external electrode electrically connected to the first electrode layer; and a second external electrode electrically connected to the second electrode layer, wherein the first external electrode is a cathode-side external electrode, and the The second external electrode is an anode-side external electrode, and the first electrode layer has a first electrode pattern in which first regions separated by slits are connected to each other via fuse portions. and the second electrode layer has a second region having an area larger than that of the first region, and the thickness of the second electrode layer is larger than the thickness of the first electrode layer. , characterized in that

According to the present invention, it is possible to provide a film capacitor whose fuse operability is less likely to deteriorate even in a high temperature environment exceeding 125°C.

FIG. 1 is a cross-sectional view schematically showing one example of the film capacitor of the present invention. FIG. 2 is a perspective view schematically showing an example of a method of obtaining a wound body constituting the film capacitor shown in FIG. 1. FIG. FIG. 3 is a perspective view schematically showing another example of the wound body forming the film capacitor shown in FIG. FIG. 4A is a top view schematically showing an example of a first electrode layer, and FIG. 4B is a top view schematically showing an example of a second electrode layer. 5A and 5B are perspective views schematically showing an example of how to use the film capacitor shown in FIG. 1. FIG. FIG. 6 is a cross-sectional view schematically showing another example of the film capacitor of the present invention. 7 is a perspective view schematically showing an example of a wound body forming the film capacitor shown in FIG. 6. FIG. 8 is a perspective view schematically showing another example of the wound body forming the film capacitor shown in FIG. 6. FIG.

The film capacitor of the present invention will be described below.
However, the present invention is not limited to the following configurations, and can be appropriately modified and applied without changing the gist of the present invention.
Combinations of two or more of the individual preferred configurations of the invention described below are also the invention.

[Film capacitor]
A film capacitor of the present invention has a first main surface and a second main surface, a first dielectric film made of resin, and a first dielectric film facing the first main surface of the first dielectric film. an electrode layer, a second electrode layer facing the second main surface of the first dielectric film, and the first dielectric film interposed between the first electrode layer or the second electrode layer a second dielectric film made of resin and having a third main surface and a fourth main surface, and a first external electrode electrically connected to the first electrode layer; and a second external electrode electrically connected to the second electrode layer, wherein the first external electrode is a cathode-side external electrode, and the The second external electrode is an anode-side external electrode, and the first electrode layer has a first electrode pattern in which first regions separated by slits are connected to each other via fuse portions. and the second electrode layer has a second region having an area larger than that of the first region, and the thickness of the second electrode layer is larger than the thickness of the first electrode layer. , characterized in that

In the film capacitor of the present invention, by increasing the thickness of the second electrode layer connected to the external electrode on the anode side, the film resistance value of the second electrode layer is reduced and the progress of the anodization reaction is slowed down. can be suppressed. Furthermore, since the first electrode layer having the first electrode pattern in which the first regions partitioned by the slits are connected to each other via the fuse portion is arranged on the cathode side, the anodic oxidation reaction does not proceed. , the fuse operability does not easily deteriorate even in a high temperature environment exceeding 125°C.
In addition, since the thickness of the first electrode layer connected to the external electrode on the anode side is smaller than the thickness of the second electrode layer, the film resistance of the first electrode layer is high and the fuse operability is enhanced. be able to.

In the film capacitor of the present invention, the first dielectric film and the second dielectric film may be laminated and wound, and the first dielectric film and the second dielectric film may It may be laminated repeatedly.
A wound film capacitor will be described below as an example of the film capacitor of the present invention.

FIG. 1 is a cross-sectional view schematically showing one example of the film capacitor of the present invention, and FIG. 2 is a perspective view schematically showing one example of a method of obtaining a wound body constituting the film capacitor shown in FIG. FIG. 3 is a perspective view schematically showing another example of the wound body forming the film capacitor shown in FIG.
In the film capacitor 1 shown in FIG. 1, a first dielectric film 10, a second dielectric film 20, a first electrode layer 30, and a second electrode layer 40 are laminated and wound. It is provided with a wound body 51 that is wrapped.
The first electrode layer 30 is provided on the first major surface 11 of the first dielectric film 10 .
The second electrode layer 40 is provided on the third major surface 21 of the second dielectric film 20 .

The thickness of the second electrode layer 40 is greater than the thickness of the first electrode layer 30 .

A first external electrode 61 is formed at one end of the wound body 51 , and the first external electrode 61 is electrically connected to the first electrode layer 30 .
The first external electrode 61 is a cathode-side external electrode.

A second external electrode 62 is formed on the other end of the wound body 51 , and the second external electrode 62 is electrically connected to the second electrode layer 40 .
The second external electrode 62 is an anode-side external electrode.

A first lead terminal 71 is connected to the first external electrode 61 , and a second lead terminal 72 is connected to the second external electrode 62 .
Since the length of the second lead terminal 72 is longer than the length of the first lead terminal 71, the second lead terminal 72 and the first lead terminal 71 can be distinguished from each other when the film capacitor 1 is viewed from the outside. It is in a good state.

As shown in FIG. 2 , in the wound body 50 , the first dielectric film 10 is wound outside the second dielectric film 20 .
A second electrode layer 40 is provided on the outer main surface (third main surface 21 ) of the second dielectric film 20 . A first electrode layer 30 is provided on the outer main surface (first main surface 11 ) of the first dielectric film 10 .
By deforming the wound body 50 shown in FIG. 2, the wound body 51 shown in FIGS. 1 and 3 is obtained.

In the film capacitor of the present invention, the surface roughness of the first main surface of the first dielectric film is preferably smaller than the surface roughness of the second main surface.
If the surface of the dielectric film has large unevenness, the surface of the first electrode layer having the first electrode patterns in which the first regions partitioned by the slits are connected to each other through the fuse portion may be deteriorated by oxidation. A defect that serves as a starting point is likely to be formed. Therefore, by providing the first electrode layer on the first main surface having the smaller surface roughness, the oxidation deterioration of the first electrode layer can be suppressed.
In the film capacitor shown in FIG. 1, the surface roughness of the first principal surface 11 is smaller than the surface roughness of the second principal surface 12 .
In FIG. 1, of the two principal surfaces (the first principal surface 11 and the second principal surface 12) of the first dielectric film 10, the principal surface (the second principal surface) with relatively larger surface roughness The surface 12) is represented by a wavy line, and the principal surface (first principal surface 11) with relatively smaller surface roughness is represented by a straight line.

In the film capacitor of the present invention, in the second dielectric film, the surface roughness of the fourth main surface is larger than the surface roughness of the third main surface, and the fourth main surface is laminated so as to face the first electrode layer It is preferable that
When the fourth main surface having a larger surface roughness is laminated so as to face the first electrode layer, the fuse portion operates and evaporates between the first electrode layer and the fourth main surface. A space for this is easily secured, and the fuse operability is improved.
In the film capacitor 1 shown in FIG. 1 , the surface roughness of the fourth principal surface 22 is greater than the surface roughness of the third principal surface 21 , and the fourth principal surface 22 is laminated so as to face the first electrode layer 30 . ing.
In FIG. 1, of the two principal surfaces (the third principal surface 21 and the fourth principal surface 22) of the second dielectric film 20, the principal surface (fourth principal surface) having relatively larger surface roughness The surface 22) is represented by a wavy line, and the principal surface (third principal surface 21) with relatively smaller surface roughness is represented by a straight line.

In the film capacitor of the present invention, the surface roughness of the first main surface is preferably 1 μm or more and 10 μm or less, more preferably 1 μm or more and less than 10 μm.

In the film capacitor of the present invention, the second main surface preferably has a surface roughness of 10 μm or more and 100 μm or less.

In the film capacitor of the present invention, the surface roughness of the third main surface is preferably 1 μm or more and 10 μm or less, more preferably 1 μm or more and less than 10 μm.

In the film capacitor of the present invention, the fourth main surface preferably has a surface roughness of 10 μm or more and 100 μm or less.

The surface roughness of the first, second, third and fourth principal surfaces means arithmetic mean roughness Ra defined in JIS B 0601:2013. The surface roughness Ra can be measured using a non-contact laser surface roughness meter (eg VK-X210 manufactured by Keyence Corporation).

In the film capacitor of the present invention, the first electrode layer has a first electrode pattern in which first regions defined by slits are interconnected via fuse portions.
Preferably, the first electrode layer further has an effective electrode portion facing the second electrode layer, and an electrode extension portion provided in a belt shape along one side edge of the first dielectric film.
At this time, it is preferable that the effective electrode portion and the lead-out electrode portion are separated by an electrode separation slit arranged parallel to the lead-out electrode portion, and connected by a fuse portion that partially crosses the electrode separation slit.
Furthermore, on the first main surface, a portion where the first electrode layer is not provided (hereinafter, referred to as a first margin (also called part).

FIG. 4A is a top view schematically showing an example of the first electrode layer.
As shown in FIG. 4A, the first electrode layer 30 is provided on the first major surface 11 of the first dielectric film 10 .
The first electrode layer 30 has an effective electrode portion 32 facing the second electrode layer 40, and an electrode extension portion 31 provided in a belt shape along one end portion 10a of the first dielectric film 10. .
The effective electrode portion 32 and the extended electrode portion 31 are separated by an electrode separation slit 33 arranged parallel to the extended electrode portion 31 and connected by a fuse portion 34 that partially crosses the electrode separation slit 33 . The effective electrode portion 32 has a first electrode pattern in which first regions 35 partitioned by electrode separating slits 33 and partitioning slits 36 (also collectively referred to as slits) are interconnected via fuse portions 34 .
Also, on the first main surface 11, the other end 10b of the first dielectric film 10 has a first margin portion 11a where the first electrode layer 30 is not provided.

In the film capacitor of the present invention, the second electrode layer has a second region with an area larger than that of the first region.
The second region may be a region partitioned by slits or may be a region not partitioned by slits.
The second electrode layer includes an effective electrode portion facing the first electrode layer, and the other side edge of the first dielectric film (the side edge of the first electrode layer where the lead-out electrode portion of the first electrode layer is provided). It is preferable to further have an electrode lead-out portion provided in a belt shape along the opposite side end.

FIG. 4B is a top view schematically showing an example of the second electrode layer.
As shown in FIG. 4B, the second electrode layer 40 is provided on the third major surface 21 of the second dielectric film 20 .
The second electrode layer 40 has an electrode lead-out portion 41 provided in a strip shape along the other end portion 20b of the second dielectric film 20, and an effective electrode portion 42 facing the first electrode layer 30. exist. No slit or the like is provided between the extended electrode portion 41 and the effective electrode portion 42 . Since the second electrode layer 40 is not provided with a slit or the like, it can be said that the second electrode layer 40 has a second region having a larger area than the first region.
Further, on the third main surface 21, one end 20a of the second dielectric film 20 has a second margin portion 21a where the second electrode layer 40 is not provided.

FIG. 4B illustrates an example of a second electrode layer having second regions not partitioned by slits, but the second electrode layer has second regions partitioned by slits. good too. However, the area of the second region is larger than the area of the first region. The second regions partitioned by the slits may be interconnected through the fuse portion.

When the areas of the first regions are different, the average area of the first regions is used for comparison with the area of the second regions. A region that exists in the second electrode layer and is larger than the average area of the first region is the second region. The second electrode layer may have a region with an area smaller than that of the first region as a region other than the second region.

The ratio of the area of the second region to the area of the first region is preferably 150% or more, more preferably 200% or more.

In the effective electrode portion of the first electrode layer, the ratio of the area that does not contribute to the capacitance of the capacitor is preferably 5% or more and 10% or less.
In addition, in the effective electrode portion of the second electrode layer, the ratio of the area that does not contribute to the capacitance of the capacitor is preferably 0% or more and less than 5%. When the ratio of the area that does not contribute to the capacitance of the capacitor is 0%, it is a so-called solid pattern.

In the film capacitor of the present invention, the wound body is preferably pressed into a flattened shape such as an ellipse or an ellipse in cross section to make it more compact.
The oblateness of the cross-sectional shape of the wound body is preferably less than 0.7. If the flatness of the cross-sectional shape of the wound body is 0.7 or more, the film capacitor may vibrate and grow loudly.
The oblateness f can be obtained by f=[(ab)/b] from the major axis a and the minor axis b when the outer shape of the wound body is measured with a vernier caliper or the like.

In the film capacitor of the present invention, the wound body may have a cylindrical winding shaft. The winding axis is arranged on the central axis of the wound first dielectric film and the second dielectric film, and the first dielectric film and the second dielectric film are wound. It becomes the winding shaft when doing.

In the film capacitor of the present invention, terminal conductors and lead terminals may be connected to the first external electrode and the second external electrode, respectively.
The film capacitor 1 shown in FIG. 1 has a first lead terminal 71 connected to the first external electrode 61 and a second lead terminal 72 connected to the second external electrode 62 .

The film capacitor 1 shown in FIG. A film capacitor with two terminal conductors is also a film capacitor of the present invention.

The film capacitor of the present invention has a specified polarity.
Specifically, the first external electrode is a cathode-side external electrode, and the second external electrode is an anode-side external electrode.
Although the method for distinguishing the polarity is not particularly limited, the length of the lead terminal connected to the anode side and the length of the lead terminal connected to the cathode side are changed (for example, the length of the lead terminal connected to the anode side is changed). The length of the lead terminal connected to the cathode side is longer than that of the lead terminal), and the surface of the film capacitor is provided with a design to distinguish the polarities.
In the film capacitor 1 shown in FIG. 1, the length of the second lead terminal 72 connected to the second external electrode 62 serving as the anode-side external electrode is equal to the length of the first external electrode 61 serving as the cathode-side external electrode. is longer than the length of the first lead terminal 71 connected to .

In the film capacitor of the present invention, the first dielectric film and the second dielectric film are laminated and wound. Also, it is preferable that the surface roughness of the main surface located on the core side is larger than the surface roughness of the main surface located on the side opposite to the core.
If the surface roughness of the principal surface located on the core side is greater than the surface roughness of the principal surface located on the side opposite to the core, the first dielectric film and the second dielectric film are laminated and wound. During winding, an air layer is less likely to be formed between the winding roll used for winding and the main surface of the laminate on the winding core side, and the film is less likely to meander. Therefore, the adhesion between the first dielectric film and the second dielectric film during winding becomes high, and the film capacitor has high heat shock resistance and current resistance.

The film capacitor of the present invention may be surrounded by an exterior resin, or housed in an exterior case, and the interior of the exterior case may be filled with a filling resin.

Thermosetting resins such as epoxy resins, silicone resins, and urethane resins are used as materials for the exterior resin or filling resin, for example. Amine curing agents and imidazole curing agents may be used as curing agents for epoxy resins. As the exterior resin or the filling resin, only the resin may be used, but a reinforcing agent may be added for the purpose of improving the strength. Silica, alumina, or the like can be used as the reinforcing agent.

Resins such as polyphenylene sulfide (PPS) and liquid crystal polymer (LCP) are used as materials for the exterior case.

An example in which the film capacitor of the present invention is housed in an exterior case will be described with reference to FIGS. 5A and 5B.
5A and 5B are perspective views schematically showing an example of how to use the film capacitor shown in FIG. 1. FIG.
As shown in FIG. 5A, the film capacitor 1 is housed in an outer case 80. As shown in FIG.
Subsequently, as shown in FIG. 5B , by filling the inside of the exterior case 80 with the filling resin 90 , the periphery of the film capacitor 1 is covered with the filling resin 90 and the opening of the exterior case 80 is sealed.
With such a method of use, the moisture resistance of the film capacitor is improved.

In the film capacitor of the present invention, the positions where the first electrode layer and the second electrode layer are provided are not particularly limited, but the first electrode layer and the second electrode layer are provided on separate dielectric films. and the case where the first electrode layer and the second electrode layer are provided on the same dielectric film.

When the first electrode layer and the second electrode layer are provided on separate dielectric films, the first electrode layer is provided on the first main surface of the first dielectric film and the second electrode layer is provided on the first main surface of the first dielectric film. is preferably provided on the third main surface of the second dielectric film.
1 and 2 (the wound body 51 in FIG. 1 and the wound body 50 in FIG. 2), the first electrode layer 30 is formed on the first main surface 11 of the first dielectric film 10. A second electrode layer 40 is provided on the third major surface 21 of the second dielectric film 20 .

When the first electrode layer and the second electrode layer are provided on the same dielectric film, the first electrode layer is provided on the first main surface of the first dielectric film, and the second electrode layer is It is preferably provided on the second main surface of the first dielectric film. In this case, no electrode layer is provided on the second dielectric film.

An example in which the first electrode layer and the second electrode layer are provided on the same dielectric film will be described with reference to FIGS. 6, 7 and 8. FIG.
FIG. 6 is a cross-sectional view schematically showing another example of the film capacitor of the present invention, and FIG. 7 is a perspective view schematically showing an example of the wound body forming the film capacitor shown in FIG. 8 is a perspective view schematically showing another example of the wound body forming the film capacitor shown in FIG. 6. FIG.
As shown in FIG. 6, the film capacitor 2 includes a first dielectric film 10, a second dielectric film 20, a first electrode layer 30, and a second electrode layer 40 which are laminated and wound. It is equipped with a wound body 53 that is wrapped.

The width _W2 of the second dielectric film 20 is smaller than the width W1 of the first dielectric film 10, and the one end _10a and the other end 10b of the first dielectric film 10 are separated from each other. A second dielectric film 20 is arranged between.

The first electrode layer 30 is provided on the first major surface 11 of the first dielectric film 10 .
The second electrode layer 40 is provided on the second major surface 12 of the first dielectric film 10 .

The thickness of the second electrode layer 40 is greater than the thickness of the first electrode layer 30 .

A first external electrode 61 that is a cathode-side external electrode is formed at one end of the wound body 53 , and the first external electrode 61 is electrically connected to the first electrode layer 30 . there is
A second external electrode 62 , which is an anode-side external electrode, is formed at the other end of the wound body 53 , and the second external electrode 62 is electrically connected to the second electrode layer 40 . there is

A first lead terminal 71 is connected to the first external electrode 61 , and a second lead terminal 72 is connected to the second external electrode 62 .
Since the length of the second lead terminal 72 is longer than the length of the first lead terminal 71, the second lead terminal 72 and the first lead terminal 71 can be distinguished from each other when the film capacitor 2 is viewed from the outside. It is in a good state.

As shown in FIG. 7, in the wound body 52, the second dielectric film 20 is wound outside the first dielectric film.
A first electrode layer 30 is provided on the outer main surface (first main surface 11 ) of the first dielectric film 10 . A second electrode layer 40 is provided on the inner main surface (second main surface 12 ) of the first dielectric film 10 .
By deforming the wound body 52 shown in FIG. 7, the wound body 53 shown in FIGS. 6 and 8 is obtained.

When the first electrode layer and the second electrode layer are provided on the same dielectric film, in the film capacitor of the present invention, the second dielectric film is wound outside the first dielectric film. In a cross section along the direction of the winding core, the width of the second dielectric film is smaller than the width of the first dielectric film, and one end and the other end of the first dielectric film A second dielectric film is preferably disposed between the ends of the .
The second dielectric film is wound outside the first dielectric film, and in a cross section along the direction of the core, the width of the second dielectric film is the width of the first dielectric film. When the width is smaller than the width and the second dielectric film is arranged between one end and the other end of the first dielectric film, one end of the first dielectric film Both the end and the other end protrude outward (both ends of the winding axis) from the second dielectric film, so the electrode layer formed on the surface of the first dielectric film The contact area between the (first electrode layer and the second electrode layer) and the external electrode is increased, and the contact between the electrode layer and the external electrode is improved.

When the first electrode layer and the second electrode layer are provided on the same dielectric film, and the second dielectric film is wound outside the first dielectric film, the present invention In the film capacitor of , in a state in which the first dielectric film and the second dielectric film are laminated, one end of the second dielectric film overlaps the electrode lead-out portion of the first electrode layer It is preferably placed in position.
Since the second dielectric film has light transmittance in the visible region to the infrared region, it is difficult to recognize its outline by image recognition or the like. However, the lead-out electrode portion (part of the first electrode layer) is arranged on the far side (inside) of one end (part of the contour) of the second dielectric film wound on the outside. In this case, the edge of the second dielectric film can be easily recognized by image recognition or the like due to the background of the electrode lead-out portion having low light transmittance in the visible region to the infrared region. Therefore, it becomes easy to manage the displacement width of the film by image recognition or the like, and deterioration of heat shock resistance and current resistance characteristics due to displacement of the film during winding can be suppressed.

[Other preferred configurations]
In the film capacitor of the present invention, the first dielectric film and the second dielectric film preferably contain a curable resin as a main component.

As used herein, the term "main component" means a component with the highest abundance (% by weight), preferably a component with an abundance of more than 50% by weight. Therefore, the dielectric resin film may contain, as components other than the main component, additives such as silicone resin, and uncured portions of starting materials such as the first organic material and the second organic material, which will be described later.

The curable resin may be a thermosetting resin or a photocurable resin.
As used herein, a thermosetting resin means a resin that can be cured by heat, and does not limit the curing method. Therefore, thermosetting resins include resins cured by methods other than heat (for example, light, electron beams, etc.) as long as they are heat-curable resins. In addition, depending on the material, a reaction may be initiated due to the reactivity of the material itself, and a material that cures without necessarily applying heat or light from the outside is also defined as a thermosetting resin. The same applies to the photocurable resin, and the curing method is not limited.

The curable resin may or may not have at least one of a urethane bond and a urea bond.
The presence of urethane bonds and/or urea bonds can be confirmed using a Fourier transform infrared spectrophotometer (FT-IR).

The dielectric resin film is preferably made of a cured product of the first organic material and the second organic material. Examples thereof include a cured product obtained by reacting a hydroxyl group (OH group) of the first organic material and an isocyanate group (NCO group) of the second organic material.

When a cured product is obtained by the reaction described above, uncured portions of the starting material may remain in the film. For example, the dielectric resin film may contain at least one of an isocyanate group (NCO group) and a hydroxyl group (OH group). In this case, the dielectric resin film may contain either one of an isocyanate group and a hydroxyl group, or may contain both an isocyanate group and a hydroxyl group.
The presence of isocyanate groups and/or hydroxyl groups can be confirmed using a Fourier transform infrared spectrophotometer (FT-IR).

The first organic material is preferably a polyol having multiple hydroxyl groups (OH groups) in its molecule. Examples of polyols include polyvinyl acetals such as polyvinyl acetoacetal, polyether polyols such as phenoxy resins, and polyester polyols. As the first organic material, two or more organic materials may be used together.

The second organic material is preferably an isocyanate compound, an epoxy resin, or a melamine resin having multiple functional groups in its molecule. As the second organic material, two or more organic materials may be used together.

Examples of isocyanate compounds include aromatic polyisocyanates such as diphenylmethane diisocyanate (MDI) and tolylene diisocyanate (TDI), and aliphatic polyisocyanates such as hexamethylene diisocyanate (HDI). Modified products of these polyisocyanates, such as modified products containing carbodiimide or urethane, may also be used.

The epoxy resin is not particularly limited as long as it has an epoxy ring, and examples thereof include bisphenol A type epoxy resin, biphenyl skeleton epoxy resin, cyclopentadiene skeleton epoxy resin, naphthalene skeleton epoxy resin, and the like.

The melamine resin is not particularly limited as long as it is an organic nitrogen compound having a triazine ring in the center of the structure and three amino groups around it, and examples thereof include alkylated melamine resins. In addition, it may be a modified form of melamine.

In the film capacitor of the present invention, the first dielectric film and the second dielectric film are desirably formed by forming a resin solution containing the first organic material and the second organic material into a film shape, followed by heat treatment. Obtained by curing.

In the film capacitor of the present invention, the first dielectric film and the second dielectric film may also contain additives for adding other functions. For example, smoothness can be imparted by adding a leveling agent. The additive is more preferably a material that has a functional group that reacts with a hydroxyl group and/or an isocyanate group and that forms part of the crosslinked structure of the cured product. Examples of such materials include resins having at least one functional group selected from the group consisting of epoxy groups, silanol groups and carboxyl groups.

Moreover, in the film capacitor of the present invention, the first dielectric film and the second dielectric film may contain a vapor-deposited polymer film as a main component. A vapor deposition polymer film refers to a film formed by a vapor deposition polymerization method, and is basically included in a curable resin.

In the film capacitor of the present invention, both the resin forming the first dielectric film and the resin forming the second dielectric film are preferably thermosetting resins.

In the film capacitor of the present invention, the thicknesses of the first dielectric film and the second dielectric film are not particularly limited, but are preferably 0.5 μm or more and 5 μm or less, respectively.
Moreover, it is preferable that the thickness of the first dielectric film and the thickness of the second dielectric film are the same.
The thicknesses of the first dielectric film and the second dielectric film can be measured using an optical film thickness meter.

In the film capacitor of the present invention, the first dielectric film and the second dielectric film are preferably made of the same material. Here, that the first dielectric film and the second dielectric film are composed of the same material means that the types of resins constituting the first dielectric film and the second dielectric film are the same. , when other ingredients are included, it means that the types and contents of the other ingredients are the same.
If the first dielectric film and the second dielectric film are made of the same material, manufacturing costs can be suppressed.

In the film capacitor of the present invention, the types of metals contained in the first electrode layer and the second electrode layer (hereinafter collectively referred to as electrode layers) are not particularly limited, but the electrode layers are aluminum (Al), titanium (Ti), zinc (Zn), magnesium (Mg), tin (Sn) and nickel (Ni).

In the film capacitor of the present invention, the thickness of the electrode layer is not particularly limited, but from the viewpoint of suppressing breakage of the electrode layer, the thickness of the electrode layer is preferably 5 nm or more and 40 nm or less.
The thickness of the electrode layer can be specified by observing a cross section obtained by cutting the first dielectric film in the thickness direction using an electron microscope such as a field emission scanning electron microscope (FE-SEM). can be done.

1, 2 film capacitor 10 first dielectric film 10a one end 10b of the first dielectric film the other end 11 first principal surface 11a first margin 12 second principal Surface 20 Second dielectric film 20a One end 20b of second dielectric film Other end 21 of second dielectric film Third major surface 21a Second margin 22 Fourth major surface 30 First electrode layer 31 first electrode layer electrode extraction portion 32 first electrode layer effective electrode portion 33 electrode separation slit 34 fuse portion 35 first region 36 division slit 40 second electrode layer 41 second electrode layer The electrode lead-out portion 42 of the effective electrode portion (second region) of the second electrode layer
50, 51, 52, 53 wound body 61 first external electrode 62 second external electrode 71 first lead terminal 72 second lead terminal 80 exterior case 90 filling resin

Claims (7)

a first dielectric film having a first main surface and a second main surface and made of resin;
a first electrode layer facing the first main surface of the first dielectric film;
a second electrode layer facing the second main surface of the first dielectric film;
a second dielectric film which is laminated on the first dielectric film via the first electrode layer or the second electrode layer, has a third main surface and a fourth main surface, and is made of a resin; ,
a first external electrode electrically connected to the first electrode layer;
A film capacitor comprising a second external electrode electrically connected to the second electrode layer,
The first external electrode is a cathode-side external electrode,
The second external electrode is an anode-side external electrode,
the first electrode layer has a first electrode pattern in which first regions partitioned by slits are connected to each other via fuse portions;
the second electrode layer has a second region having a larger area than the first region;
The thickness of the second electrode layer is greater than the thickness of the first electrode layer,
The first electrode layer is provided on the first main surface of the first dielectric film,
The second electrode layer is provided on the third main surface of the second dielectric film,
In the first dielectric film, the surface roughness of the first main surface is smaller than the surface roughness of the second main surface,
In the second dielectric film, the surface roughness of the fourth principal surface is greater than the surface roughness of the third principal surface,
A film capacitor, wherein the fourth main surface is laminated so as to face the first electrode layer. a first dielectric film having a first main surface and a second main surface and made of resin;
a first electrode layer facing the first main surface of the first dielectric film;
a second electrode layer facing the second main surface of the first dielectric film;
a second dielectric film which is laminated on the first dielectric film via the first electrode layer or the second electrode layer, has a third main surface and a fourth main surface, and is made of a resin; ,
a first external electrode electrically connected to the first electrode layer;
A film capacitor comprising a second external electrode electrically connected to the second electrode layer,
The first external electrode is a cathode-side external electrode,
The second external electrode is an anode-side external electrode,
the first electrode layer has a first electrode pattern in which first regions partitioned by slits are connected to each other via fuse portions;
the second electrode layer has a second region having a larger area than the first region;
The thickness of the second electrode layer is greater than the thickness of the first electrode layer,
The first electrode layer is provided on the first main surface of the first dielectric film,
The second electrode layer is provided on the second main surface of the first dielectric film,
In the first dielectric film, the surface roughness of the first main surface is smaller than the surface roughness of the second main surface,
In the second dielectric film, the surface roughness of the fourth principal surface is greater than the surface roughness of the third principal surface,
A film capacitor, wherein the fourth main surface is laminated so as to face the first electrode layer. a first dielectric film having a first main surface and a second main surface and made of resin;
a first electrode layer facing the first main surface of the first dielectric film;
a second electrode layer facing the second main surface of the first dielectric film;
a second dielectric film which is laminated on the first dielectric film via the first electrode layer or the second electrode layer, has a third main surface and a fourth main surface, and is made of a resin; ,
a first external electrode electrically connected to the first electrode layer;
A film capacitor comprising a second external electrode electrically connected to the second electrode layer,
The first external electrode is a cathode-side external electrode,
The second external electrode is an anode-side external electrode,
the first electrode layer has a first electrode pattern in which first regions partitioned by slits are connected to each other via fuse portions;
the second electrode layer has a second region having a larger area than the first region;
The thickness of the second electrode layer is greater than the thickness of the first electrode layer,
The first electrode layer is provided on the first main surface of the first dielectric film,
The second electrode layer is provided on the third main surface of the second dielectric film,
The first dielectric film and the second dielectric film are laminated and wound,
In both the first dielectric film and the second dielectric film, the surface roughness of the main surface located on the core side is larger than the surface roughness of the main surface located on the side opposite to the core. A film capacitor characterized by : a first dielectric film having a first main surface and a second main surface and made of resin;
a first electrode layer facing the first main surface of the first dielectric film;
a second electrode layer facing the second main surface of the first dielectric film;
a second dielectric film which is laminated on the first dielectric film via the first electrode layer or the second electrode layer, has a third main surface and a fourth main surface, and is made of a resin; ,
a first external electrode electrically connected to the first electrode layer;
A film capacitor comprising a second external electrode electrically connected to the second electrode layer,
The first external electrode is a cathode-side external electrode,
The second external electrode is an anode-side external electrode,
the first electrode layer has a first electrode pattern in which first regions partitioned by slits are connected to each other via fuse portions;
the second electrode layer has a second region having a larger area than the first region;
The thickness of the second electrode layer is greater than the thickness of the first electrode layer,
The first electrode layer is provided on the first main surface of the first dielectric film,
The second electrode layer is provided on the second main surface of the first dielectric film,
The first dielectric film and the second dielectric film are laminated and wound,
In both the first dielectric film and the second dielectric film, the surface roughness of the main surface located on the core side is larger than the surface roughness of the main surface located on the side opposite to the core. A film capacitor characterized by: In the first dielectric film, the surface roughness of the first main surface is smaller than the surface roughness of the second main surface,
In the second dielectric film, the surface roughness of the fourth principal surface is greater than the surface roughness of the third principal surface,
5. The film capacitor according to claim 3 , wherein said fourth main surface is laminated so as to face said first electrode layer. 6. The film capacitor according to claim 1, wherein said first dielectric film and said second dielectric film are made of the same material. 7. The film capacitor according to claim 1, wherein said resin constituting said first dielectric film and said resin constituting said second dielectric film are both thermosetting resins.

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