WO2024070067A1

WO2024070067A1 - Film capacitor and module

Info

Publication number: WO2024070067A1
Application number: PCT/JP2023/021733
Authority: WO
Inventors: 賢城岸
Original assignee: 株式会社村田製作所
Priority date: 2022-09-30
Filing date: 2023-06-12
Publication date: 2024-04-04

Abstract

Provided is a film capacitor in which a laminate film covering a capacitor element is hardly damaged even when being sandwiched by means of pressure force. A film capacitor (1) according to the present invention includes: a capacitor element (10) including an element body (11) having end surfaces (11e) located on both ends in the longitudinal direction (L) and lateral surfaces (11s) connecting the end surfaces (11e) to each other, and external electrodes (12) provided on the end surfaces (11e) of the element body (11); a laminate film (20) covering the capacitor element (10); and an intermediate member (30) disposed at at least a portion between the capacitor element (10) and the laminate film (20).

Description

Film capacitors and modules

The present invention relates to a film capacitor and a module.

A type of capacitor known is a film capacitor, which uses a flexible resin film as the dielectric film with opposing metal layers sandwiched between the dielectric film. The capacitor elements that make up a film capacitor are manufactured, for example, by creating a laminate in which a metalized film having a metal layer provided on the surface of a dielectric film is wound or laminated, and then forming external electrodes (also called metallikon electrodes) on both end faces of the laminate.

Patent Document 1 discloses that in order to use such a film capacitor in a high-humidity, high-temperature environment, the film capacitor is wrapped in a laminate material that has a high barrier property against moisture, etc., and also discloses a motor that includes a capacitor wrapped in a laminate material.
That is, Patent Document 1 discloses a motor that is characterized by having a motor drive capacitor that is enclosed in a laminate material and sealed with its terminal parts exposed to the outside, and is built in between the motor shell and the outer periphery of the stator coil.

Japanese Patent No. 4294446

In order to fix a film capacitor wrapped in a laminate material as described in Patent Document 1 to a substrate or a housing without using adhesives, etc., it is necessary to clamp the film capacitor with a constant pressure. When a film capacitor wrapped in a laminate material is clamped with a constant pressure, if the pressure increases, the laminate film will be strongly pressed against the external electrodes of the film capacitor.
Generally, external electrodes are formed by metal spraying, but their surfaces are rough and not very smooth, so when the laminate film is pressed strongly against the external electrodes, pressure is concentrated in one part of the laminate film, causing the laminate film to easily break.

The present invention has been made to solve the above problems, and the object of the present invention is to provide a film capacitor in which the laminate film covering the capacitor element is not easily damaged even when clamped with pressure. Furthermore, the object of the present invention is to provide a module that includes the above film capacitor.

The film capacitor of the present invention includes a capacitor element including an element body having end faces located at both ends in the longitudinal direction and side faces connecting the end faces, and external electrodes provided on the end faces of the element body, a laminate film covering the capacitor element, and an intermediate member disposed at least partially between the capacitor element and the laminate film.

The module of the present invention comprises a substrate, a fixture arranged on the substrate, and the film capacitor of the present invention that is attached to the substrate of the fixture, and the side of the element body of the film capacitor is attached to the fixture via the laminate film of the film capacitor.

The present invention can provide a film capacitor in which the laminate film covering the capacitor element is not easily damaged even when clamped with pressure. Furthermore, the present invention can provide a module including the above-mentioned film capacitor.

FIG. 1A is a perspective view illustrating an example of a film capacitor according to an embodiment of the present invention. FIG. 1B is a cross-sectional view taken along line AA of FIG. 1A. FIG. 1C is an exploded view of the film capacitor according to the first embodiment of the present invention shown in FIG. 1A. FIG. 2A is a cross-sectional view illustrating a schematic diagram of another example of an external electrode included in the film capacitor according to the first embodiment of the present invention. FIG. 2B is a cross-sectional view illustrating typically another example of an external electrode included in the film capacitor according to the first embodiment of the present invention. FIG. 3A is a perspective view illustrating a schematic example of a wound film capacitor. FIG. 3B is a cross-sectional view of the element body shown in FIG. 3A taken along line BB. FIG. 4 is a perspective view that shows a schematic example of the first metallized film and the second metallized film that constitute the element body that constitutes the capacitor element shown in FIGS. 3A and 3B. FIG. 5A is a perspective view illustrating an example of a module according to the first embodiment of the present invention. FIG. FIG. 5B is a cross-sectional view of the module shown in FIG. 5A taken along line CC. FIG. 5C is a cross-sectional view of the module shown in FIG. 5A taken along line DD. FIG. 6A is a cross-sectional view illustrating an example of a film capacitor according to a second embodiment of the present invention. FIG. 6B is an exploded view of an example of the film capacitor according to the second embodiment of the present invention. FIG. 7A is a cross-sectional view illustrating an example of a film capacitor according to a third embodiment of the present invention. FIG. 7B is an exploded view of an example of the film capacitor according to the third embodiment of the present invention. FIG. 8A is a cross-sectional view illustrating an example of a film capacitor according to a fourth embodiment of the present invention. FIG. 8B is an exploded view of an example of the film capacitor according to the fourth embodiment of the present invention.

The film capacitor of the present invention will be described below.
The film capacitor of the present invention includes a capacitor element including an element body having end faces located at both ends in the longitudinal direction and side faces connecting the end faces to each other, and external electrodes provided on the end faces of the element body, a laminate film covering the capacitor element, and an intermediate member arranged at least partially between the capacitor element and the laminate film.
As long as the film capacitor of the present invention has the above-mentioned configuration, it may be modified as appropriate without departing from the spirit and scope of the present invention.

In this specification, terms indicating the relationship between elements (e.g., "vertical," "parallel," "orthogonal," etc.) and terms indicating the shapes of elements are not expressions that only express a strict meaning, but also expressions that include a range of substantial equivalence, for example, differences of about a few percent. In addition, the drawings shown below are schematic diagrams, and the dimensions, aspect ratio, etc. may differ from those of the actual product.

The embodiments described below are merely examples, and it goes without saying that partial replacement or combination of the configurations shown in different embodiments is possible. In addition, a combination of multiple individual preferred configurations described below also constitutes the present invention.
In the second and subsequent embodiments, the description of the matters common to the first and second embodiments will be omitted, and only the differences will be described. In particular, the same effects and advantages due to the same configurations will not be mentioned in each embodiment.

First Embodiment
First, a film capacitor according to a first embodiment of the present invention will be described with reference to the drawings.
FIG. 1A is a perspective view illustrating an example of a film capacitor according to an embodiment of the present invention.
FIG. 1B is a cross-sectional view taken along line AA of FIG. 1A.
FIG. 1C is an exploded view of the film capacitor according to the first embodiment of the present invention shown in FIG. 1A.

The film capacitor 1 shown in Figures 1A, 1B, and 1C includes a capacitor element 10, a laminate film 20 that covers the capacitor element 10, and an intermediate member 30 that is disposed between the capacitor element 10 and the laminate film 20.

The capacitor element 10 includes an element body 11 having end faces 11e located at both ends in the longitudinal direction (the direction indicated by the arrow L in Figures 1A, 1B, and 1C) and side faces 11s connecting the end faces 11e, and a pair of external electrodes 12 provided on both end faces 11e of the element body 11.

1C, the element body 11 has, for example, a racetrack-shaped end face 11e and a columnar shape as a whole. The side face 11s of the element body 11 is composed of a flat portion _11s1 formed in a flat shape and a curved portion _11s2 formed in a curved shape.

The external electrode 12 is, for example, in the form of a plate, and is shaped to cover the end surface 11 e of the element body 11 .
As shown in Figures 1B and 1C, the external electrode 12 has an end face 12e that is visible when the external electrode 12 is viewed in a plane from the longitudinal direction L, and a side face 12s that is visible when the external electrode 12 is viewed in a plane from a direction perpendicular to the longitudinal direction L.
As shown in FIG. 1C, the end face 12e of the external electrode 12 has a racetrack shape in plan view.
The side surface s of the external electrode 12 is composed of a flat portion _12s1 formed in a flat shape and a curved portion _12s2 formed in a curved shape.

As shown in Figures 1B and 1C, a pull-out terminal 40 electrically connected to the external electrode 12 is formed on the end surface 12e of the external electrode 12. Also, as shown in Figure 1C, insulating resin 41 is disposed at the base of the protruding portion of the pull-out terminal 40. The insulating resin 41 is heat-welded to the laminate film 20, and also fixes the pull-out terminal 40.

1A, 1B, and 1C, laminate film 20 is formed by bonding a pair of upper and lower laminate materials 21 that cover capacitor element 10. Laminate material 21 has a shape that follows the outer shape of capacitor element 10, and has, for example, a flange portion 22 on the outer edge. Laminate material 21 may also have a drawing opening 23 for drawing out drawing terminal 40.
The pair of laminate materials 21 are heat-welded to each other at the flange portion 22 to form the laminate film 20. At the outlet 23, the insulating resin 41 and the flange portion 22 are heat-welded to each other.

1B and 1C , in the film capacitor 1, the intermediate member 30 is disposed at least between the external electrode 12 and the laminate film 20. More specifically, the intermediate member 30 continuously covers the flat portion _11s1 of the side surface 11s of the element body 11 and the flat portion _12s1 of the side surface 12s of the external electrode 12.
Therefore, in the film capacitor 1, the side surface 12s of the external electrode 12 and the laminate film 20 are separated from each other and are not in direct contact with each other.

In the film capacitor 1 , the Young's modulus of the intermediate member 30 is preferably lower than the Young's modulus of the external electrodes 12 .
The ratio of the Young's modulus of the external electrode 12 to the Young's modulus of the intermediate member 30 is preferably 20 or more and 25,000 or less when expressed as Young's modulus of external electrode/Young's modulus of intermediate member.

When the film capacitor 1 is clamped with a pressure force in a direction perpendicular to the longitudinal direction L, the laminate film 20 is pressed against the flat portion 12 s ₁ of the side surface 12 s of the external electrode 12 via the intermediate member 30 .
As described above, since the Young's modulus of the intermediate member 30 is lower than that of the external electrode 12, the pressure applied to the laminate film 20 is reduced compared to when the laminate film 20 is directly pressed against the flat portion _12s1 of the side surface 12s of the external electrode 12. As a result, damage to the laminate film 20 can be prevented.
Furthermore, if the intermediate member 30 is made of a material that is easily elastically deformed, the pressure applied to the laminate film 20 is dispersed, making it possible to prevent the pressure from concentrating in one area.
That is, in the film capacitor 1 , the intermediate member 30 functions as a buffer material that protects the external electrodes 12 .

In addition, in Figures 1B and 1C, the external electrode 12 is plate-shaped, and the angle between the end face 12e of the external electrode 12 and the side face 12s of the external electrode 12 is 90 degrees. Therefore, in Figure 1B, the end face 12e of the external electrode 12 and the side face 12s of the external electrode 12 are clearly separated without overlapping.

In the film capacitor of the present invention, the external electrode may have a shape in which the corners are chamfered. The chamfered portion is visible when the external electrode is viewed in a plan view from the longitudinal direction, and is also visible when the external electrode is viewed in a plan view from a direction perpendicular to the longitudinal direction. In other words, the chamfered portion belongs to both the end face and the side face of the external electrode. Thus, in the film capacitor of the present invention, the external electrode may have a portion that belongs to both the end face and the side face of the external electrode.
Such an embodiment will be described below with reference to the drawings.

2A and 2B are cross-sectional views illustrating schematic diagrams of another example of an external electrode included in the film capacitor according to the first embodiment of the present invention.
An external electrode 12' shown in Figs. 2A and 2B has the same configuration as the external electrode 12 described above, except that corners 12R' are chamfered.
In Fig. 2A, the range (the portion indicated by the reference symbol "A1" in Fig. 2A) that can be seen when the external electrode 12' is viewed in plan from the longitudinal direction L is the end face 12e'. In Fig. 2B, the range (the portion indicated by the reference symbol "A2" in Fig. 2B) that can be seen when the external electrode 12' is viewed in plan from a direction perpendicular to the longitudinal direction L is the end face 12e'.
Thus, in the external electrode 12', the corner portion 12R' belongs to both the end face 12e' of the external electrode 12' and the side face 12s' of the external electrode 12'.
In the film capacitor according to the first embodiment of the present invention, the external electrodes may have such a shape.

The individual components of the film capacitor are described in detail below.

(Capacitor element)
In the capacitor element of the film capacitor according to the first embodiment of the present invention, the element body may be a wound film capacitor in which a metallized film is laminated and wound, or it may be a laminated film capacitor in which a metallized film is laminated.

In the following description, a wound film capacitor in which the element body is wound with a metallized film laminated thereon will be described.
FIG. 3A is a perspective view illustrating a schematic example of a wound film capacitor.
FIG. 3B is a cross-sectional view of the element body shown in FIG. 3A taken along line BB.

In the capacitor element 10 shown in Figures 3A and 3B, the element body 11 is a laminate including a first metallized film 51 and a second metallized film 52. The element body 11 is a wound body in which the first metallized film 51 and the second metallized film 52 are wound in a laminated state. A pair of external electrodes 12 are electrically connected to both end faces of the element body 11.

As shown in FIG. 3B, the first metallized film 51 includes a first dielectric film 53 and a first metal layer 55 provided on the surface of the first dielectric film 53, and the second metallized film 52 includes a second dielectric film 54 and a second metal layer 56 provided on the surface of the second dielectric film 54.

As shown in FIG. 3B, the first metal layer 55 and the second metal layer 56 face each other with the first dielectric film 53 or the second dielectric film 54 sandwiched therebetween. Furthermore, the first metal layer 55 is electrically connected to one of the external electrodes 12, and the second metal layer 56 is electrically connected to the other external electrode 12.

The first dielectric film 53 and the second dielectric film 54 may have different configurations, but preferably have the same configuration.

The first metal layer 55 is formed on one side of the first dielectric film 53 so as to reach one edge, but not to reach the other edge. On the other hand, the second metal layer 56 is formed on one side of the second dielectric film 54 so as not to reach one edge, but to reach the other edge. The first metal layer 55 and the second metal layer 56 are composed of, for example, an aluminum layer.

FIG. 4 is a perspective view showing a schematic example of a first metallized film and a second metallized film that constitute the element body of the capacitor element shown in FIGS. 3A and 3B.

3B and 4, the first dielectric film 53 and the second dielectric film 54 are stacked with a shift in the width direction (left and right direction in FIG. 3B) so that the end of the first metal layer 55 that reaches the side edge of the first dielectric film 53 and the end of the second metal layer 56 that reaches the side edge of the second dielectric film 54 are both exposed from the stacked films. As shown in FIG. 4, the element body 11 becomes a roll of metallized films by rolling up the first dielectric film 53 and the second dielectric film 54 in a stacked state, and is stacked with the first metal layer 55 and the second metal layer 56 exposed at their ends.

In Figures 3B and 4, the second dielectric film 54 is wound on the outside of the first dielectric film 53, and the first metal layer 55 and the second metal layer 56 of each of the first dielectric film 53 and the second dielectric film 54 are wound so that they face inward.

The roll of metallized film may have a cylindrical winding shaft. The winding shaft is disposed on the central axis of the rolled metallized film and serves as the winding shaft when winding the metallized film.

When such a roll of metallized film is pressed from above and below into a flat shape, the end faces become racetrack-shaped and the overall shape of the element body becomes columnar.

The external electrodes 12 are formed by spraying, for example, zinc, on each end face of the element body 11 obtained as described above. One external electrode 12 contacts the exposed end of the first metal layer 55 and is thereby electrically connected to the first metal layer 55. The other external electrode 12 contacts the exposed end of the second metal layer 56 and is thereby electrically connected to the second metal layer 56.

In the film capacitor of the present invention, the dielectric film constituting the element body of the capacitor element may contain a curable resin as a main component, or may contain a thermoplastic resin as a main component. From the viewpoint of improving the heat resistance of the film capacitor, it is preferable that the dielectric film contains a curable resin as a main component.

In this specification, the "main component of the dielectric film" means the component with the largest weight percentage, and preferably means the component with a weight percentage exceeding 50% by weight. Therefore, the dielectric film may contain, as components other than the main component, for example, additives such as silicone resin, and uncured portions of starting materials such as the first organic material and second organic material described below.

The curable resin may be a thermosetting resin or a photocurable resin.

In this specification, thermosetting resin means a resin that can be cured by heat, and does not limit the curing method. Therefore, as long as it is a resin that can be cured by heat, resins that have been cured by methods other than heat (for example, light, electron beams, etc.) are also included in thermosetting resins. Furthermore, depending on the material, a reaction may be initiated due to the reactivity of the material itself, and resins that cure without necessarily being exposed to external heat or light are also considered to be thermosetting resins. The same applies to photocurable resins, 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. Examples of such resins include urethane resins having urethane bonds, and urea resins having urea bonds. The curable resin may also be a resin having both urethane bonds and urea bonds.

The presence of urethane bonds and/or urea bonds can be confirmed using a Fourier transform infrared spectrophotometer (FT-IR).

The curable resin is preferably a cured product of a first organic material and a second organic material. For example, it may be a cured product obtained by reacting a hydroxyl group (OH group) of the first organic material with an isocyanate group (NCO group) of the second organic material.

When a cured product is obtained by the above reaction, uncured portions of the starting material may remain in the film. For example, the dielectric film may contain at least one of an isocyanate group and a hydroxyl group. In this case, the dielectric film may contain either an isocyanate group or 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 in the molecule. Examples of polyols include polyether polyol, polyester polyol, and polyvinyl acetal. Two or more types of organic materials may be used in combination as the first organic material.

The second organic material is preferably an isocyanate compound, an epoxy resin, or a melamine resin, each of which has multiple functional groups in its molecule. Two or more organic materials may be used in combination as the second organic material. Of the second organic materials, an isocyanate compound is preferable.

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 versions of these polyisocyanates, such as modified versions with carbodiimide or urethane, may also be used.

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

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

In the film capacitor of the present invention, the dielectric film constituting the element body of the capacitor element is preferably obtained by forming a resin solution containing the first organic material and the second organic material into a film, and then curing it by heat treatment.

In the film capacitor of the present invention, the dielectric film constituting the element body of the capacitor element may contain a vapor deposition polymer film as a main component. The vapor deposition polymer film may or may not have at least one of a urethane bond and a urea bond.

In addition, vapor deposition polymerization films refer to films formed using the vapor deposition polymerization method, and are basically included in the category of curable resins.

In the film capacitor of the present invention, the dielectric film constituting the element body of the capacitor element may contain a thermoplastic resin as a main component. Examples of the thermoplastic resin include polypropylene, polyethersulfone, polyetherimide, polyarylate, etc.

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

In the film capacitor of the present invention, the thickness of the dielectric film that constitutes the element body of the capacitor element is not particularly limited, but it is preferable to design it appropriately according to the required capacitance and required element volume of the capacitor to be manufactured.

The thickness of the dielectric film can be measured using an optical film thickness gauge.

In the film capacitor of the present invention, the type of metal contained in the metal layer constituting the element body of the capacitor element is not particularly limited, but it is preferable that the metal layer contains at least one metal selected from the group consisting of aluminum, titanium, zinc, magnesium, tin, and nickel.

In the film capacitor of the present invention, the thickness of the metal layer constituting the element body of the capacitor element is not particularly limited, but from the viewpoint of suppressing damage to the metal layer, it is preferable that the thickness of the metal layer is 5 nm or more and 40 nm or less.

The thickness of the metal layer can be determined by observing a cross section of the metallized film cut in the thickness direction using an electron microscope such as a field emission scanning electron microscope (FE-SEM).

In the film capacitor of the present invention, the lead terminal connected to the external electrode is preferably a lead wire or a bus bar. The lead terminal is preferably connected to the external electrode by welding.

In the film capacitor of the present invention, the material constituting the insulating resin arranged at the base of the protruding portion of the pull-out terminal is not particularly limited as long as it can be heat-sealed to the laminate film and can fix the pull-out terminal, but it is preferable that it is, for example, a polyolefin-based thermoplastic resin such as polypropylene.

(Laminate film)
In the film capacitor according to the first embodiment of the present invention, the laminate film is a laminate material having a high barrier property against moisture, and is not particularly limited as long as the laminate materials can be thermally welded to each other.
An example of such a laminate film is a laminate film configured by laminating a first resin layer, a metal film, and a second resin layer in this order from the side closest to the capacitor element.

The first resin layer is a layer for thermally welding the laminate films together, and is preferably made of, for example, a polyolefin-based thermoplastic resin such as polypropylene resin.
The thickness of the first resin layer is preferably 20 μm or more and 150 μm or less.

The metal film is a layer for improving the barrier properties against moisture, and is preferably made of a vapor-deposited metal film.
The metal film is preferably made of a metal material such as aluminum.
The thickness of the metal film is preferably 20 μm or more and 50 μm or less.

The second resin layer is a layer for improving the barrier property against moisture and protecting the metal film, and is preferably made of a resin material such as nylon resin or polyethylene terephthalate resin.
The thickness of the second resin layer is preferably 10 μm or more and 40 μm or less.

In the film capacitor according to the first embodiment of the present invention, the total thickness of the laminate film is preferably 80 μm or more and 200 μm or less, and more preferably 100 μm or more and 160 μm or less.
If the thickness of the laminate film is less than 80 μm, the strength of the laminate film is reduced and the laminate film becomes more susceptible to breakage.
If the thickness of the laminate film exceeds 200 μm, the processability of the laminate film may deteriorate, and the overall size of the film capacitor may become large, making it difficult to miniaturize products using the film capacitor.

(Intermediate part)
In the film capacitor according to the first embodiment of the present invention, the intermediate member may be made of any material capable of dispersing and equalizing the pressure applied to the laminate film, but it is preferable that the intermediate member be made of a resin material such as silicone rubber, fluororubber, urethane rubber, or elastic epoxy resin.
Since these materials have high elasticity, the intermediate member made of these materials functions favorably as a cushioning material.

In the film capacitor according to the first embodiment of the present invention, the thickness of the intermediate member is preferably designed appropriately depending on the pressure applied, the size of the capacitor element, etc., and is more preferably 0.2 mm or more and 2 mm or less, and even more preferably 0.5 mm or more and 1.2 mm or less.
If the thickness of the intermediate member is less than 0.2 mm, the intermediate member is too thin and it becomes difficult to distribute the pressure on the laminate film.
If the thickness of the intermediate member exceeds 2 mm, the overall size of the film capacitor tends to become large, and heat dissipation properties tend to deteriorate.

In the film capacitor according to the first embodiment of the present invention, the Young's modulus of the intermediate member is preferably 5 MPa or more and 4 GPa or less, and more preferably 10 MPa or more and 700 MPa or less.
When the Young's modulus of the intermediate member is within the above range, the intermediate member has sufficient strength, and when the film capacitor according to the first embodiment of the present invention is clamped with a pressure, the pressure applied to the laminate film is easily distributed and uniformed.

In the film capacitor according to the first embodiment of the present invention, the intermediate member may contain a heat-transmitting material. When the intermediate member contains a heat-conducting material, the heat dissipation property of the film capacitor can be improved.
Examples of thermally conductive materials include inorganic materials such as aluminum oxide, magnesium oxide, silica, silicon nitride, boron nitride, and aluminum nitride.

The film capacitor 1 can be manufactured, for example, by the following method.
First, the capacitor element 10, a pair of laminating materials 21, and a pair of intermediate members 30 are prepared.
Next, the intermediate member 30 is disposed on the capacitor element 10 so as to continuously cover the flat portion 11 s ₁ of the side surface 11 s of the element body 11 and the flat portion 12 s ₁ of the side surface 12 s of the external electrode 12 .
Next, the capacitor element 10 with the intermediate member 30 disposed thereon is sandwiched from above and below between a pair of laminate materials 21. At this time, the lead-out terminal 40 of the capacitor element 10 is drawn out from the lead-out opening 23 of the laminate material 21, and the insulating resin 41 disposed at the base of the protruding portion of the lead-out terminal 40 is made to come into contact with the lead-out opening 23.
Thereafter, the flange portion 22 of the laminate material 21 is heat-pressed to heat-weld the flange portion 22 and integrate the laminate material 21. At this time, the flange portion 22 is also heat-welded to the insulating resin 41 arranged at the base of the protruding portion of the lead-out terminal 40. Note that the heat-welding process is preferably performed in a vacuum in order to eliminate the air and moisture present therein. The heat-welding process in a vacuum can effectively suppress the swelling of the laminate material 21 caused by the expansion of the air present when the film capacitor 1 is exposed to high temperatures, and the oxidation of the evaporated metal caused by the influence of the air and moisture present therein. Note that the heat-welding process in a vacuum causes the laminate film 20 to deform somewhat so as to conform to the internal members, but does not affect the characteristics of the film capacitor 1.
By the above method, the film capacitor 1 can be manufactured.

Next, a module in which the film capacitor according to the first embodiment of the present invention is used will be described.
A module including the film capacitor according to the first embodiment of the present invention is one aspect of the present invention.
The module according to the first embodiment of the present invention comprises a substrate, a fixing device arranged on the substrate, and a film capacitor according to the first embodiment of the present invention engaged with the substrate of the fixing device, the fixing device engaging a side of the element body of the film capacitor via the laminate film of the film capacitor.

Such a module according to the first embodiment of the present invention will be described below with reference to the drawings.
FIG. 5A is a perspective view illustrating an example of a module according to the first embodiment of the present invention. FIG.
Fig. 5B is a cross-sectional view of the module shown in Fig. 5A taken along line CC, and Fig. 5C is a cross-sectional view of the module shown in Fig. 5A taken along line DD.
That is, FIG. 5B is a cross-sectional view of the module shown in FIG. 5A cut through the external electrode of the capacitor element, and FIG. 5C is a cross-sectional view of the module shown in FIG. 5A cut through the element body of the capacitor element.

The module 60 shown in FIG. 5A includes a substrate 70 , a fixture 80 disposed on the substrate 70 , and a film capacitor 1 secured by the fixture 80 .
In an actual product, the lead-out terminal 40 of the film capacitor 1 is connected to other members. However, for the sake of convenience, the other members are omitted from the illustration in FIG. 5A.

In the module 60 shown in FIGS. 5A, 5B, and 5C, the film capacitor ₁ is arranged such that the planar portion 11s1 of the side surface 11s of the element body ₁₁ and the planar portion 12s1 of the side surface 12s of the external electrode 12 are positioned perpendicular to the main surface 71 of the substrate 70, and the length direction L is parallel to the main surface 71 of the substrate 70.

As shown in FIGS. 5A, 5B, and 5C, the fixture 80 has a gripping portion 81.
The fixing tool 80 has a gripping portion 81 that engages the side surface 11 s of the element body 11 of the film capacitor 1 via the laminate film 20 of the film capacitor 1 .

In such a module 60, the film capacitor 1 receives a pressure force from the side surface 11s of the element body 11 toward the center of the element body 11.

If the film capacitor does not have an intermediate member, the laminate film and the external electrode will be in direct contact, and the laminate film will be pressed directly against the external electrode by the above pressure. Since the surface of the external electrode is rough and not very smooth, when the above pressure is applied to the film capacitor, the pressure will be concentrated in one part of the laminate film, making the laminate film prone to damage.

However, in module 60, as shown in FIG. 5B, an intermediate member 30 is disposed between laminate film 20 and external electrode 12. Therefore, the pressure on laminate film 20 is dispersed more than if laminate film 20 were pressed directly against external electrode 12. This makes it possible to prevent pressure from concentrating on one part of laminate film 20, and as a result, it is possible to prevent damage to laminate film 20.

In the above module 60, the film capacitor 1 is arranged so that the flat portion _11s1 of the side surface 11s of the element body 11 and the flat portion 12s1 of the side surface 12s of the external electrode ₁₂ are positioned perpendicular to the main surface 71 of the substrate 70 and the length direction L is parallel to the main surface 71 of the substrate 70, but in the module according to the first embodiment of the present invention, the film capacitor may be arranged on the substrate in any state as long as the side surface of the element body of the film capacitor is fastened by a fastener via the laminate film of the film capacitor. For example, the film capacitor may be arranged so that its length direction intersects with the main surface of the substrate.
Such a module can be manufactured by changing the shape of the gripping portion, the shape of the fixture such as the arrangement position of the gripping portion, etc.

The material of the substrate 70 in the module 60 is not particularly limited, but examples include resin materials such as epoxy resin and ceramic materials such as alumina. In addition, fillers or woven fabrics made of inorganic or organic materials may be added to the material of the substrate 70.

The fixing device 80 in the module 60 is not particularly limited, but may be a screw-type fixing device, a clip-type fixing device, a spring-type fixing device, etc.

Second Embodiment
Next, a film capacitor according to a second embodiment of the present invention will be described.
The film capacitor of the second embodiment of the present invention has the same configuration as the film capacitor of the first embodiment of the present invention, except that instead of the intermediate member continuously covering the flat portion of the side surface of the element body and the flat portion of the side surface of the external electrode, the intermediate member is arranged so as to cover the end face of the external electrode.

A film capacitor according to a second embodiment of the present invention will be described with reference to the drawings.
FIG. 6A is a cross-sectional view illustrating an example of a film capacitor according to a second embodiment of the present invention.
FIG. 6B is an exploded view of an example of the film capacitor according to the second embodiment of the present invention.

As shown in FIGS. 6A and 6B , in the film capacitor 101 , an intermediate member 130 is disposed so as to cover an end surface 12 e of the external electrode 12 .
As shown in FIG. 6B, the intermediate member 130 has a notch 131 for leading out the lead-out terminal 40 .
Note that the cutout portion 131 in Figure 6B has a shape in which a continuous cutout extends from the center to the outer edge of the intermediate member 130, but in the film capacitor according to the second embodiment of the present invention, the cutout portion may be formed as a through hole.

The film capacitor 101 is clamped with a pressure applied in a direction parallel to the longitudinal direction L.
When the film capacitor 101 is clamped with a pressure force in a direction parallel to the longitudinal direction L, the laminate film 20 is pressed against the end faces 12 e of the external electrodes 12 via the intermediate members 130 .
Therefore, the pressure applied to the laminate film 20 is dispersed more than when the laminate film 20 is directly pressed against the end surface 12e of the external electrode 12. This makes it possible to prevent the pressure from concentrating on a portion of the laminate film 20, and as a result, it is possible to prevent the laminate film 20 from being damaged.
That is, in the film capacitor 101 , the intermediate member 130 functions as a buffer material that protects the external electrodes 12 .

Third Embodiment
Next, a film capacitor according to a third embodiment of the present invention will be described.
The film capacitor of the third embodiment of the present invention has the same configuration as the film capacitor of the first embodiment of the present invention, except that instead of the intermediate member continuously covering the flat portion of the side surface of the element body and the flat portion of the side surface of the external electrode, the intermediate member continuously covers the side surface of the external electrode and the outer edge of the end face of the external electrode, and is positioned so as to expose a portion of the end face of the external electrode.

A film capacitor according to a third embodiment of the present invention will be described with reference to the drawings.
FIG. 7A is a cross-sectional view illustrating an example of a film capacitor according to a third embodiment of the present invention.
FIG. 7B is an exploded view of an example of the film capacitor according to the third embodiment of the present invention.

7A and 7B , in the film capacitor 201, the intermediate member 230 is disposed so as to continuously cover the entire periphery of the side surface 12s of the external electrode 12 and the outer edge of the end face 12e of the external electrode 12, and to expose a part of the end face 12e of the external electrode 12. In other words, the intermediate member 230 has an opening 231 that exposes the end face 12e of the external electrode 12.
As shown in FIG. 7B , the lead-out terminal 40 is led out from the opening 231 of the intermediate member 230 .

The film capacitor 201 may be clamped with a pressure force in a direction parallel to the length direction L, or may be clamped with a pressure force in a direction perpendicular to the length direction L.
Regardless of the direction from which pressure is applied to the film capacitor 201 , the laminate film 20 is pressed against the side surface 12 s or the end surface 12 e of the external electrode 12 via the intermediate member 230 .
Therefore, the pressure applied to the laminate film 20 is dispersed more than when the laminate film 20 is directly pressed against the side surface 12s or the end surface 12e of the external electrode 12. This makes it possible to prevent pressure from concentrating on a portion of the laminate film 20, and as a result, it is possible to prevent damage to the laminate film 20.
That is, in the film capacitor 201 , the intermediate member 230 functions as a buffer material that protects the external electrodes 12 .

Fourth Embodiment
Next, a film capacitor according to a fourth embodiment of the present invention will be described.
The film capacitor according to the fourth embodiment of the present invention differs from the film capacitor according to the first embodiment of the present invention in the position and function of the intermediate member. Note that in the film capacitor according to the fourth embodiment of the present invention, the capacitor element and the laminate film have the same configurations as those in the film capacitor according to the first embodiment of the present invention.

FIG. 8A is a cross-sectional view illustrating an example of a film capacitor according to a fourth embodiment of the present invention.
FIG. 8B is an exploded view of an example of the film capacitor according to the fourth embodiment of the present invention.

As shown in FIGS. 8A and 8B, in a film capacitor 301, an intermediate member 330 is disposed so as to cover a flat portion _11s1 of a side surface 11s of an element body 11.
In addition, the flat portion _12s1 of the side surface 12s of the external electrode 12 is separated from the laminate film 20. Furthermore, the flat portion _12s1 of the side surface 12s of the external electrode 12 is exposed, and a space 302 is formed between the laminate film 20 and the flat portion _12s1 of the side surface 12s of the external electrode 12.

In the film capacitor 301 , the intermediate member 330 functions as a spacer for forming a space 302 between the laminate film 20 and the flat portion 12 s ₁ of the side surface 12 s of the external electrode 12 .

The film capacitor 301 is sandwiched by a pressure applied from the side surface 11 s of the element body 11 toward the center of the element body 11 .
Even if the film capacitor 301 is clamped with a pressure applied from the side surface 11s of the element body 11 toward the center of the element body 11, the intermediate member 330 functions as a spacer, so that the laminate film 20 does not come into contact with the external electrode 12, or even if it does come into contact, the laminate film 20 is not pressed strongly against the external electrode.
Therefore, damage to the laminate film 20 can be prevented.

In the film capacitor 301 , the Young's modulus of the intermediate member 330 is preferably lower than the Young's modulus of the external electrodes 12 .
The ratio of the Young's modulus of the external electrode 12 to the Young's modulus of the intermediate member 330 is preferably 20 or more and 25,000 or less when expressed as Young's modulus of external electrode/Young's modulus of intermediate member.

In the film capacitor according to the fourth embodiment of the present invention, the Young's modulus of the intermediate member 330 is preferably 5 MPa or more and 4 GPa or less, and more preferably 10 MPa or more and 700 MPa or less.

In the film capacitor according to the fourth embodiment of the present invention, the intermediate member may be made of any material as long as it can function as a spacer, but it is preferable that the intermediate member be made of a resin material such as silicone rubber, fluororubber, urethane rubber, or elastic epoxy resin.
These materials function favorably as spacers.

In the film capacitor according to the fourth embodiment of the present invention, the thickness of the intermediate member is preferably designed appropriately depending on the pressure applied, the size of the capacitor element, etc., and is more preferably 0.2 mm or more and 2 mm or less, and even more preferably 0.5 mm or more and 1.2 mm or less.
If the thickness of the intermediate member is less than 0.2 mm, the intermediate member will be too thin, making it difficult to form a space between the laminate film and the external electrode.
If the thickness of the intermediate member exceeds 2 mm, the overall size of the film capacitor tends to become large, and heat dissipation properties tend to deteriorate.

Other Embodiments
In the film capacitors according to the first to fourth embodiments of the present invention, the element body has end faces in a racetrack shape, and the entire film capacitor is a cylindrical wound film capacitor. However, the shape of the film capacitor of the present invention is not limited to the above shape, and may be a cylindrical shape or an elliptical cylindrical shape.
Furthermore, the film capacitor of the present invention may be a laminated film capacitor in which a metallized film is laminated, and its shape may be a rectangular parallelepiped or a cube.

In the film capacitors according to the first to third embodiments of the present invention, the intermediate member is disposed so as to cover a portion of the external electrode.
In the film capacitor of the present invention, when the intermediate member functions as a cushioning material, the intermediate member may be arranged in any manner as long as it is located at least partially between the laminate film and the external electrode in the direction in which pressure is applied.

For example, the insulating layer 12 may be disposed so as to cover the entire side surface of the external electrode, or may be disposed so as to cover a part of the side surface of the external electrode.
Furthermore, when the intermediate member functions as a cushioning material, in the film capacitor of the present invention, the intermediate member may be arranged so as to cover the entire side surface of the element body, may be arranged so as to cover part of the side surface of the element body, or may not be arranged on the side surface of the element body.

In the film capacitor according to the fourth embodiment of the present invention, the intermediate member is disposed so as to cover a portion of the side surface of the element body.
In the film capacitor of the present invention, when the intermediate member functions as a cushioning material, the intermediate member may be positioned in any manner so long as it is positioned at least partially between the laminate film and the element body in the direction in which pressure is applied and at least a portion of the side surface of the external electrode is separated from the laminate film.
For example, the intermediate member may be disposed so as to cover the entire side surface of the element body.

Furthermore, in the film capacitor according to the fourth embodiment of the present invention, the side surfaces of the external electrodes and the laminate film are spaced apart from each other, forming a space therebetween.
In the film capacitor according to the present invention, when the intermediate member functions as a cushioning material, the cushioning material is arranged in the area where the side surface of the external electrode and the laminate film are separated, so that no space does not have to be formed.

This specification includes the following:

The present disclosure (1) is a film capacitor including a capacitor element including an element body having end faces located at both ends in the longitudinal direction and side faces connecting the end faces, and external electrodes provided on the end faces of the element body, a laminate film covering the capacitor element, and an intermediate member disposed at least partially between the capacitor element and the laminate film.

The present disclosure (2) is a film capacitor according to the present disclosure (1) in which the Young's modulus of the intermediate member is lower than the Young's modulus of the external electrode.

The present disclosure (3) is a film capacitor according to the present disclosure (1) or (2), in which the intermediate member is disposed between the external electrode and the laminate film.

The present disclosure (4) is a film capacitor according to the present disclosure (3), in which the external electrode has an end face visible when the external electrode is viewed in a planar view from the longitudinal direction and a side face visible when the external electrode is viewed in a planar view from a direction perpendicular to the longitudinal direction, and the intermediate member is arranged so as to cover at least a portion of the side face of the external electrode.

The present disclosure (5) is a film capacitor according to the present disclosure (3), in which the external electrode has an end face visible when the external electrode is viewed in a planar view from the longitudinal direction and a side face visible when the external electrode is viewed in a planar view from a direction perpendicular to the longitudinal direction, and the intermediate member is arranged to continuously cover the outer edges of the side face and the end face of the external electrode and to expose at least a portion of the end face of the external electrode.

The present disclosure (6) is a film capacitor according to the present disclosure (4) or (5), in which the intermediate member continuously covers the side surface of the element body and the side surface of the external electrode.

The present disclosure (7) is a film capacitor according to the present disclosure (3), in which the external electrode has an end face visible when the external electrode is viewed in a planar view from the longitudinal direction and a side face visible when the external electrode is viewed in a planar view from a direction perpendicular to the longitudinal direction, and the intermediate member is arranged so as to cover at least a portion of the end face of the external electrode.

The present disclosure (8) is a film capacitor according to the present disclosure (1) or (2), in which the external electrode has an end face visible when the external electrode is viewed in a planar view from the longitudinal direction and a side face visible when the external electrode is viewed in a planar view from a direction perpendicular to the longitudinal direction, the intermediate member is arranged to cover the side face of the element body, and at least a portion of the side face of the external electrode is separated from the laminate film.

The present disclosure (9) is a film capacitor according to the present disclosure (8), in which the side of the external electrode that is away from the laminate film is exposed, and a space is formed between the laminate film and the exposed portion of the side of the external electrode.

The present disclosure (10) is a module comprising a substrate, a fixture disposed on the substrate, and a film capacitor according to any one of the present disclosures (4) to (6), (8), and (9) that is secured to the substrate of the fixture, in which the side of the element body of the film capacitor is secured to the fixture via the laminate film of the film capacitor.

1, 101, 201, 301 Film capacitor 10 Capacitor element 11 Element body 11e End face 11s of element body Side face 11s of element body ₁ Flat portion 11s of side face of element body ₂ Curved portion 12, 12' of side face of element

body External electrode

12e, 12e': End face 12R' of

external electrode Corner

12s, 12s' of external electrode Side face 12s of external electrode ₁ Flat portion 12s of side face of external electrode ₂ Curved portion 20 of side face of external electrode Laminate film 21 Laminate material 22 Flange portion 23

Lead outlet

30, 130, 230, 330 Intermediate member 40 Lead terminal 41 Insulating resin 51 First metallized film 52 Second metallized film 53 First dielectric film 54 Second dielectric film 55 First metal layer 56 Second metal layer 60 Module 70 Substrate 71 Main surface 80 of substrate Fixture 81 Grip portion 131 Notch portion 231 Opening 302 Space

Claims

a capacitor element including an element body having end faces located at both ends in a longitudinal direction and side faces connecting the end faces, and an external electrode provided on the end faces of the element body;
a laminate film covering the capacitor element;
A film capacitor comprising: an intermediate member disposed at least partially between the capacitor element and the laminate film.
The film capacitor of claim 1, wherein the Young's modulus of the intermediate member is lower than the Young's modulus of the external electrode.
The film capacitor according to claim 1 or 2, wherein the intermediate member is disposed between the external electrode and the laminate film.
the external electrode has an end face that is seen when the external electrode is viewed in a planar manner from a longitudinal direction, and a side face that is seen when the external electrode is viewed in a planar manner from a direction perpendicular to the longitudinal direction,
The film capacitor according to claim 3 , wherein the intermediate member is disposed so as to cover at least a portion of a side surface of the external electrode.
the external electrode has an end face that is seen when the external electrode is viewed in a planar manner from a longitudinal direction, and a side face that is seen when the external electrode is viewed in a planar manner from a direction perpendicular to the longitudinal direction,
The film capacitor according to claim 3 , wherein the intermediate member is disposed so as to continuously cover the side surfaces of the external electrodes and the outer edges of the end faces of the external electrodes, and to expose at least a portion of the end faces of the external electrodes.
The film capacitor according to claim 4 or 5, wherein the intermediate member continuously covers the side surface of the element body and the side surface of the external electrode.
the external electrode has an end face that is seen when the external electrode is viewed in a planar manner from a longitudinal direction, and a side face that is seen when the external electrode is viewed in a planar manner from a direction perpendicular to the longitudinal direction,
The film capacitor according to claim 3 , wherein the intermediate member is disposed so as to cover at least a portion of an end surface of the external electrode.
the external electrode has an end face that is seen when the external electrode is viewed in a planar manner from a longitudinal direction, and a side face that is seen when the external electrode is viewed in a planar manner from a direction perpendicular to the longitudinal direction,
The intermediate member is disposed so as to cover a side surface of the element body,
3. The film capacitor according to claim 1, wherein at least a part of a side surface of the external electrode is separated from the laminate film.
The film capacitor of claim 8, wherein the side of the external electrode that is away from the laminate film is exposed, and a space is formed between the laminate film and the exposed portion of the side of the external electrode.
A substrate;
A fixture disposed on the substrate;
and a film capacitor according to any one of claims 4 to 6, 8 and 9, which is fixed to the substrate of the fixture;
A module in which the side of the element body of the film capacitor is engaged by the fixing device via the laminate film of the film capacitor.