WO2021039761A1

WO2021039761A1 - Film capacitor

Info

Publication number: WO2021039761A1
Application number: PCT/JP2020/031955
Authority: WO
Inventors: 亮真島; 賢城岸; 菊池　公明; 亀井　聡
Original assignee: 株式会社村田製作所; 株式会社指月電機製作所
Priority date: 2019-08-30
Filing date: 2020-08-25
Publication date: 2021-03-04
Also published as: JPWO2021039761A1; JP7244032B2; CN114051646A

Abstract

A film capacitor 1 of the present invention comprises: a capacitor element 5 including a stack 10 and a pair of external electrodes (a first external electrode 51 and a second external electrode 52) provided on both end surfaces, in a width direction W perpendicular to a stacking direction T, of the stack 10, the stack 10 having films stacked therein in the stacking direction T, the films including a metalized film (a first metalized film 21 and a second metalized film 22) comprising a dielectric film (a first dielectric film 31 and a second dielectric film 32) with a metal layer (a first metal layer 41 and a second metal layer 42) provided on a major surface thereof; external lead-out terminals (a first external lead-out terminal 61 and a second external lead-out terminal 62) connected to the external electrodes (the first external electrode 51 and the second external electrode 52); a separating material 70 covering a part of the capacitor element 5 and a part of the external lead-out terminals (the first external lead-out terminal 61 and the second external lead-out terminal 62); an exterior case 80 having an opening 81 in one end and accommodating the capacitor element 5; and a filler resin 90 with which the exterior case 80 is filled and in which the capacitor element 5 is buried. The stack 10 has an upper surface 10A positioned on the opening 81 side of the exterior case 80. The separating material 70 covers portions of the external lead-out terminals (the first external lead-out terminal 61 and the second external lead-out terminal 62) that are connected to the external electrodes (the first external electrode 51 and the second external electrode 52) and the external electrodes (the first external electrode 51 and the second external electrode 52), and does not cover at least a part of the upper surface 10A of the stack 10. The filler resin 90 is provided in a region enclosed by the external electrodes (the first external electrode 51 and the second external electrode 52), the external lead-out terminals (the first external lead-out terminal 61 and the second external lead-out terminal 62), and the separating material 70, and in a region between the separating material 70 and the exterior case 80.

Description

Film capacitor

The present invention relates to a film capacitor.

The film capacitor has a capacitor element in which a metallized film having a metal layer provided on the surface of a dielectric film is wound or laminated. Such a capacitor element is manufactured, for example, by laminating or laminating two metallized films and then forming a pair of external electrodes on both end faces thereof. Then, after forming the external lead-out terminal connected to the external electrode, the capacitor element may be housed in the outer case, and the filling resin may be filled in the outer case.

When such a film capacitor is moved to a low temperature environment, the linear expansion coefficient of the metallized film laminate (including the wound body) is larger than the linear expansion coefficient of the filling resin, so that the external electrode becomes the surrounding filling resin. In the restrained state, the laminate of the metallized film tries to shrink. Therefore, tensile stress is generated in the external electrode, and cracks occur.

On the other hand, when the film capacitor is moved from the low temperature environment to the high temperature environment, the filling resin around the external electrode and the outer case begin to expand before the metallized film laminate. Therefore, tensile stress is generated in the external electrode, and cracks occur.

As described above, the film capacitor has a problem that cracks occur in the external electrode when used in a wide temperature range. In particular, in in-vehicle applications such as automobiles, high reliability is required in a wide temperature range, and therefore, it is important to solve the above problems.

In response to the above problem, Patent Document 1 describes a case in which the upper end surface is open and a single or a plurality of capacitor elements housed in the case in which metallized films are used and metallikon electrodes are provided at both ends. Disclosed is a metallized film capacitor comprising an external lead-out terminal connected to a metallikon electrode and a resin composition for burying a capacitor element filled in a case, and the metallikon electrode coated with a release material.

Japanese Unexamined Patent Publication No. 2010-16160

On the other hand, in order to realize high reliability of the film capacitor, it is also important to suppress the infiltration of water into the external electrode. On the other hand, in the metallized film capacitor described in Patent Document 1, the metallikon electrode is coated with a release material, but there is room for improvement in suppressing the infiltration of water into the external electrode.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a film capacitor in which the occurrence of cracks in an external electrode is suppressed and the infiltration of water into the external electrode is suppressed. Is what you do.

The film capacitor of the present invention is a laminate in which a film containing a metallized film having a metal layer provided on a main surface of a dielectric film is laminated in the lamination direction, and the laminate in a width direction orthogonal to the lamination direction. A release material that covers a capacitor element having a pair of external electrodes provided on both end surfaces of the capacitor element, an external lead-out terminal connected to the external electrode, a part of the capacitor element, and a part of the external lead-out terminal. An outer case having an opening at one end and accommodating the capacitor element inside, and a filling resin filled in the outer case and burying the capacitor element are provided, and the laminate is the outer case. The release material has an upper surface located on the opening side of the above, covers the connection portion of the external extraction terminal with the external electrode and the external electrode, and covers at least a part of the upper surface of the laminate. The filler is not covered and is provided in a region surrounded by the external electrode, the external extraction terminal, and the release material, and in a region between the release material and the outer case.

According to the present invention, it is possible to provide a film capacitor in which the occurrence of cracks in the external electrode is suppressed and the infiltration of water into the external electrode is suppressed.

It is a perspective schematic diagram which shows an example of the film capacitor of this invention. It is a perspective schematic diagram which shows the state which disassembled the film capacitor in FIG. It is sectional drawing which shows the part corresponding to the line segment A1-A2 in FIG. It is sectional drawing which shows the part corresponding to the line segment B1-B2 in FIG. It is sectional drawing which shows the part corresponding to the line segment C1-C2 in FIG. It is a perspective schematic diagram which shows the capacitor element in FIG. It is sectional drawing which shows the part corresponding to the line segment D1-D2 in FIG. It is a perspective schematic diagram which shows the 1st method about the process of providing the release material in the manufacturing method of the film capacitor of this invention. It is a perspective schematic diagram which shows the 1st method about the process of providing the release material in the manufacturing method of the film capacitor of this invention. It is a perspective schematic diagram which shows the 2nd method about the process of providing the release material in the manufacturing method of the film capacitor of this invention. It is a perspective schematic diagram which shows the 2nd method about the process of providing the release material in the manufacturing method of the film capacitor of this invention. It is a graph which shows the measurement result of the change rate of the equivalent series resistance with respect to the film capacitor of Example 1 and Comparative Example 1.

Hereinafter, the film capacitor of the present invention will be described. The present invention is not limited to the following configuration, and may be appropriately modified without departing from the gist of the present invention. In addition, a combination of a plurality of individual preferred configurations described below is also the present invention.

[Film capacitor]
As an example of the film capacitor of the present invention, a so-called winding type film in which a film containing a metallized film having a metal layer provided on at least one main surface of a dielectric film is wound in a laminated state. The capacitor will be described below. The film capacitor of the present invention may be a so-called laminated film capacitor in which the above films are laminated.

FIG. 1 is a schematic perspective view showing an example of the film capacitor of the present invention. FIG. 2 is a schematic perspective view showing a state in which the film capacitor in FIG. 1 is disassembled. FIG. 2 shows a state before the capacitor element with the external extraction terminal is housed in the outer case. FIG. 3 is a schematic cross-sectional view showing a portion corresponding to the line segments A1-A2 in FIG. FIG. 4 is a schematic cross-sectional view showing a portion corresponding to the line segments B1-B2 in FIG. FIG. 5 is a schematic cross-sectional view showing a portion corresponding to the line segments C1-C2 in FIG.

In the present specification, the stacking direction and the width direction of the film capacitor are defined by arrows T and W, respectively, as shown in FIGS. 1, 2, 3, 4, and 5, respectively. It can be said that the winding type film capacitor has a plurality of stacking directions, but in the present specification, the direction is defined by the arrow T. Here, the stacking direction T and the width direction W are orthogonal to each other.

As shown in FIGS. 1, 2, 3, 4, and 5, the film capacitor 1 is peeled off from the capacitor element 5, the first external extraction terminal 61, and the second external extraction terminal 62. It has a material 70, an outer case 80, and a filling resin 90.

<Capacitor element>
FIG. 6 is a schematic perspective view showing the capacitor element in FIG. FIG. 7 is a schematic cross-sectional view showing a portion corresponding to the line segments D1-D2 in FIG. As shown in FIGS. 6 and 7, the capacitor element 5 includes a laminate 10, a first external electrode 51 provided on one end surface of the laminate 10 in the width direction W, and a laminate in the width direction W. It has a second external electrode 52 provided on the other end face of the ten. Here, both end faces of the laminated body 10 face each other in the width direction W.

The laminated body 10 has an upper surface 10A, a lower surface 10B, and a side surface 10C in addition to both end faces provided with the first external electrode 51 and the second external electrode 52. As shown in FIGS. 3 and 4, when the capacitor element 5 is housed in the outer case 80, the upper surface 10A of the laminated body 10 is located on the opening 81 side of the outer case 80. The lower surface 10B of the laminated body 10 faces the upper surface 10A and is located on the bottom surface side of the outer case 80. The side surfaces 10C of the laminated body 10 are a pair of surfaces facing each other in the stacking direction T. As shown in FIG. 4, the upper surface 10A and the lower surface 10B of the laminated body 10 may be rounded.

As shown in FIG. 7, the laminated body 10 is a wound body in which the first metallized film 21 and the second metallized film 22 are wound in a state of being laminated in the stacking direction T. The film capacitor 1 is a winding type film capacitor having a laminated body 10 which is also such a winding body.

In the capacitor element 5, from the viewpoint of reducing the height of the capacitor element 5, the cross-sectional shape of the laminated body 10 is pressed into a flat shape such as an ellipse or an oval, and the cross-sectional shape of the laminated body 10 is a perfect circle. It is preferable that the shape has a small thickness.

The capacitor element 5 may have a columnar winding shaft. The winding shaft is arranged on the central axis of the first metallized film 21 and the second metallized film 22 in the wound state, and the first metallized film 21 and the second metallized film 22 are arranged. It serves as a winding shaft when winding 22.

The first metallized film 21 has a first metal layer 41 provided on one main surface of the first dielectric film 31.

The first metal layer 41 is provided so as to reach one side edge of the first metallized film 21 and not reach the other side edge of the first metallized film 21 in the width direction W.

The second metallized film 22 is one in which a second metal layer 42 is provided on one main surface of the second dielectric film 32.

The second metal layer 42 is provided so as not to reach one side edge of the second metallized film 22 but to reach the other side edge of the second metallized film 22 in the width direction W.

In the laminated body 10, the end portion of the first metal layer 41 on the side reaching the side edge of the first metallized film 21 is exposed on one end surface of the laminated body 10, and the second metal layer 42 The adjacent first metallized film 21 and the second metallized film 22 are arranged so that the end portion on the side reaching the side edge of the second metallized film 22 is exposed to the other end surface of the laminated body 10. It is deviated in the width direction W.

Since the laminate 10 is wound in a state where the first metallized film 21 and the second metallized film 22 are laminated in the lamination direction T, the first metal layer 41 and the first dielectric material are formed. It can also be said that the film 31, the second metal layer 42, and the second dielectric film 32 are wound in a state of being laminated in order in the stacking direction T.

In the laminated body 10, the first metallized film 21 is inside the second metallized film 22, the first metal layer 41 is inside the first dielectric film 31, and the second metal layer 42 is inside. The first metallized film 21 and the second metallized film 22 are wound in a laminated state in the stacking direction T so as to be inside the second dielectric film 32.

The second metal layer 42 may be provided not on one main surface of the second dielectric film 32 but on the other main surface of the first dielectric film 31. In this case, in the laminated body 10, the first metal layer 41 is provided on one main surface of the first dielectric film 31, and the second metal layer 42 is provided on the other main surface. The metallized film and the second dielectric film 32 are wound in a state of being laminated in the stacking direction T.

It is preferable that the first dielectric film 31 and the second dielectric film 32 each contain a curable resin as a main component. Here, the principal component means a component having the largest weight percentage, and preferably means a component having a weight percentage larger than 50% by weight.

The curable resin may be a thermosetting resin or a photocurable resin. The thermosetting resin means a resin that can be cured by heat, and does not limit the curing method. Therefore, as long as the resin can be cured by heat, the thermosetting resin also includes a resin cured by a method other than heat (for example, light, electron beam, etc.). Further, depending on the material, the reaction may be started due to the reactivity of the material itself, and a thermosetting resin is also used if the material is cured without necessarily applying heat or light from the outside. The same applies to the photocurable resin, and the curing method is not limited as long as the resin can be cured by light.

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

The curable resin is preferably composed of a cured product of the first organic material and the second organic material. Examples of such a cured product include a cured product obtained by reacting a hydroxyl group (OH group) contained in the first organic material with an isocyanate group (NCO group) contained in the second organic material. When a cured product is obtained by such a reaction, an uncured portion of the starting material may remain in the dielectric film. For example, the first dielectric film 31 and the second dielectric film 32 may each contain at least one of a hydroxyl group and an isocyanate group. In this case, the first dielectric film 31 and the second dielectric film 32 may each contain one of a hydroxyl group and an isocyanate group, or may contain both a hydroxyl group and an isocyanate group. .. The presence of hydroxyl groups and / or isocyanate groups can be confirmed using a Fourier transform infrared spectrophotometer.

The first organic material is preferably a polyol having a plurality of hydroxyl groups in the molecule. Examples of the polyol include polyvinyl acetal such as polyvinyl acetal acetal, polyether polyol such as phenoxy resin, polyester polyol and the like. As the first organic material, a plurality of types of organic materials may be used in combination.

The second organic material is preferably an isocyanate compound, an epoxy resin, or a melamine resin having a plurality of functional groups in the molecule. As the second organic material, a plurality of types of organic materials may be used in combination.

Examples of the isocyanate compound include aromatic polyisocyanates such as diphenylmethane diisocyanate (MDI) and tolylene diisocyanate (TDI), and aliphatic polyisocyanates such as hexamethylene diisocyanate (HDI). The isocyanate compound may be a modified product of these polyisocyanates, for example, a modified product having carbodiimide, urethane, or the like.

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

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. The melamine resin may be a modified form of melamine.

The first dielectric film 31 and the second dielectric film 32 are preferably formed by forming a resin solution containing the first organic material and the second organic material into a film, and then heat-treating and curing the resin solution. It is made.

The first dielectric film 31 and the second dielectric film 32 may each contain a vapor-deposited polymer film as a main component. The vapor-deposited polymerized film may have at least one of a urethane bond and a urea bond, or may not have both a urethane bond and a urea bond. The thin-film deposition polymer film refers to a film formed by a thin-film deposition polymerization method, and is basically included in a curable resin.

The first dielectric film 31 and the second dielectric film 32 may each contain a thermoplastic resin as a main component. Examples of the thermoplastic resin include polypropylene, polyether sulfone, polyetherimide, polyarylate and the like.

Each of the first dielectric film 31 and the second dielectric film 32 has uncured portions of starting materials such as silicone resin, first organic material and second organic material as components other than the main components. Etc. may be contained.

The first dielectric film 31 and the second dielectric film 32 may each contain additives for adding various functions. Examples of the additive include a leveling agent for imparting smoothness. The additive preferably has a functional group that reacts with a hydroxyl group and / or an isocyanate group, and forms a part of the crosslinked structure of the cured product. Examples of such an additive include a resin having at least one functional group selected from the group consisting of a hydroxyl group, an epoxy group, a silanol group, and a carboxyl group.

The compositions of the first dielectric film 31 and the second dielectric film 32 may be different from each other, but are preferably the same.

The thickness of the first dielectric film 31 and the second dielectric film 32 is preferably 0.5 μm or more and 5 μm or less, respectively. The thicknesses of the first dielectric film 31 and the second dielectric film 32 may be different from each other, but are preferably the same.

The thickness of the first dielectric film 31 and the second dielectric film 32 can be measured using an optical film thickness meter.

Examples of the constituent materials of the first metal layer 41 and the second metal layer 42 include metals such as aluminum, zinc, titanium, magnesium, tin, and nickel, respectively.

The compositions of the first metal layer 41 and the second metal layer 42 may be different from each other, but are preferably the same.

The thicknesses of the first metal layer 41 and the second metal layer 42 are preferably 5 nm or more and 40 nm or less, respectively.

The thickness of the first metal layer 41 can be specified by observing the cut surface of the first metallized film 21 in the thickness direction using a transmission electron microscope (TEM). The thickness of the second metal layer 42 can be specified in the same manner.

The first external electrode 51 is provided on one end surface of the laminated body 10 and is connected to the first metal layer 41 by coming into contact with the exposed end portion of the first metal layer 41.

From the viewpoint of connectivity between the first metal layer 41 and the first external electrode 51, at one end surface of the laminate 10, the first metallized film 21 has a width with respect to the second metallized film 22. It is preferable that it protrudes in the direction W.

The second external electrode 52 is provided on the other end surface of the laminated body 10 and is connected to the second metal layer 42 by coming into contact with the exposed end portion of the second metal layer 42.

From the viewpoint of connectivity between the second metal layer 42 and the second external electrode 52, at the other end face of the laminate 10, the second metallized film 22 has a width with respect to the first metallized film 21. It is preferable that it protrudes in the direction W.

Examples of the constituent materials of the first external electrode 51 and the second external electrode 52 include metals such as zinc, aluminum, tin, and zinc-aluminum alloy. The first external electrode 51 and the second external electrode 52 are preferably formed by spraying a metal as described above onto one end face and the other end face of the laminate 10, respectively.

The compositions of the first external electrode 51 and the second external electrode 52 may be different from each other, but are preferably the same.

The configuration of the laminated body 10 may be different from the configuration as shown in FIG. For example, in the first metallized film 21, the first metal layer 41 is divided into two metal layers in the width direction W, one metal layer reaches one side edge of the first metallized film 21, and the other. The metal layer may be provided so as to reach the other side edge of the first metallized film 21. In this case, in the first metal layer 41, one metal layer is connected to the first external electrode 51, and the other metal layer is connected to the second external electrode 52, while the second metal layer 42 is connected. Is provided so as not to be connected to both the first external electrode 51 and the second external electrode 52, a capacitor can be formed between the first metal layer 41 and the second metal layer 42.

<External drawer terminal>
As shown in FIGS. 2, 3, 4, and 5, the first external extraction terminal 61 is connected to the first external electrode 51. The first external lead-out terminal 61 may be electrically connected to the first external electrode 51 via, for example, a solder layer. The first external drawer terminal 61 projects from the inside of the outer case 80 toward the outside.

The connection position between the first external lead-out terminal 61 and the first external electrode 51 may be the central portion of the first external electrode 51, as described in FIG. 1 of Japanese Patent No. 4733566. It may be the end of the first external electrode 51 close to the opening 81 of the outer case 80.

The second external extraction terminal 62 is connected to the second external electrode 52. The second external extraction terminal 62 may be electrically connected to the second external electrode 52, for example, via a solder layer. The second external drawer terminal 62 projects from the inside of the outer case 80 toward the outside.

The connection position between the second external extraction terminal 62 and the second external electrode 52 may be the central portion of the second external electrode 52, as described in FIG. 1 of Japanese Patent No. 4733566. It may be the end of the second external electrode 52 close to the opening 81 of the outer case 80.

Examples of the constituent materials of the first external lead-out terminal 61 and the second external lead-out terminal 62 include metals such as copper, tin, and aluminum.

The compositions of the first external extraction terminal 61 and the second external extraction terminal 62 may be different from each other, but are preferably the same.

The shape of the first external drawer terminal 61 and the second external drawer terminal 62 may be linear (rod-shaped) or plate-shaped.

The shapes of the first external extraction terminal 61 and the second external extraction terminal 62 may be different from each other, but are preferably the same.

<Exterior case>
As shown in FIGS. 2, 3 and 4, the outer case 80 is provided with an opening 81 at one end and houses the capacitor element 5 inside.

The shape of the outer case 80 is not particularly limited as long as it has an opening 81 at one end, and is, for example, a bottomed square cylinder having a square cylindrical side wall portion as shown in FIG. It may be a bottomed cylinder having a cylindrical side wall portion.

Examples of the constituent material of the outer case 80 include metals such as aluminum, magnesium, iron, stainless steel, and copper, alloys of these metals, resins such as polybutylene terephthalate, polyphenylene sulfide, and liquid crystal polymer (LCP). ..

When the constituent material of the outer case 80 is a metal or alloy as described above, the water vapor barrier property of the outer case 80 is enhanced. Therefore, even if the film capacitor 1 is used in a high temperature and high humidity environment, the hydroxylation reaction of the first metal layer 41 and the second metal layer 42 due to the infiltration of water is less likely to proceed, and as a result, it becomes difficult to proceed. The decrease in capacitance is suppressed. On the other hand, since the conductivity of the outer case 80 is also increased, it may be necessary to take measures for insulation between the first external drawer terminal 61 and the second external drawer terminal 62 and the outer case 80.

When the constituent material of the outer case 80 is a metal or alloy as described above, the outer case 80 is manufactured by, for example, impact molding or the like.

When the constituent material of the exterior case 80 is a resin composition containing a resin having high insulating properties as described above, the above-mentioned insulating measures are not required. In particular, when the resin composition constituting the outer case 80 contains a liquid crystal polymer, the water vapor barrier property of the outer case 80 is enhanced.

Examples of the liquid crystal polymer contained in the resin composition include a liquid crystal polymer having a p-hydroxybenzoic acid and a 6-hydroxy-2-naphthoic acid group in the skeleton. In addition to the p-hydroxybenzoic acid and the 6-hydroxy-2-naphthoic acid group, a liquid crystal polymer having a polycondensate formed by using various components such as phenol, phthalic acid, and ethylene terephthalate can be used. Further, when classifying liquid crystal polymers, there are classification methods such as type I, type II, and type III, but the material means the same material as the liquid crystal polymer formed from the above components.

The content of the liquid crystal polymer in the resin composition is preferably 40% by weight or more and 95% by weight or less, and more preferably 40% by weight or more and 85% by weight or less.

The resin composition preferably contains an inorganic filler in addition to the liquid crystal polymer. As the inorganic filler, a material having higher strength than the liquid crystal polymer can be used. The inorganic filler is preferably a material having a melting point higher than that of the liquid crystal polymer, and more preferably a material having a melting point of 680 ° C. or higher.

The form of the inorganic filler is not particularly limited, and examples thereof include a form having a longitudinal direction such as a fibrous shape or a plate shape. A plurality of types of inorganic materials may be used in combination as the inorganic filler having such a form. The resin composition preferably contains at least one of a fibrous inorganic material and a plate-shaped inorganic material as the inorganic filler.

In the present specification, the fibrous means that the relationship between the longitudinal length of the filler in the longitudinal direction and the cross-sectional diameter in the cross section perpendicular to the longitudinal direction is the longitudinal length / cross-sectional diameter ≥ 5 (that is, the aspect ratio is It means a state of 5: 1 or more). Here, the cross-sectional diameter is the longest distance between two points on the outer circumference of the cross-section. If the cross-sectional diameter differs in the longitudinal direction, the measurement is performed at the point where the cross-sectional diameter is maximum.

In the present specification, the plate shape means a state in which the relationship between the cross-sectional diameter of the surface having the maximum projected area and the maximum height in the direction perpendicular to this cross-section is cross-sectional diameter / maximum height ≥ 3. To do.

The resin composition may contain an inorganic filler that satisfies both the fibrous and plate-like conditions described above. In this case, the inorganic filler contains only one type of inorganic material. However, also in this case, it is said that "the resin composition contains both a fibrous inorganic material and a plate-shaped inorganic material as an inorganic filler".

The inorganic filler has a portion that is oriented toward the opening 81 from the bottom side and a portion that is oriented toward the adjacent side wall in each side wall of the side portion of the exterior case 80. It is preferable that it has and is dispersed inside the outer case 80.

The size of the inorganic filler is preferably a size having a diameter of 5 μm or more and a length of 50 μm or more.

It is preferable that the inorganic filler is dispersed throughout the outer case 80 without agglomeration.

Examples of the inorganic filler include inorganic materials such as glass fiber, mica, talc, various oxides, and various hydroxides.

The content of the inorganic filler in the resin composition is preferably 5% by weight or more, more preferably 15% by weight or more. Further, from the viewpoint of ensuring the moldability of the outer case 80, the content of the inorganic filler in the resin composition is preferably 60% by weight or less.

The content of the inorganic filler in the resin composition is measured by measuring the residual component as an inorganic component by ash content measurement or thermogravimetric analysis using a test piece having a thickness of 20 mm × 20 mm × 0.5 mm. It can be calculated from the measured initial weight and residual component weight. More specifically, based on the JIS K 7250 A method (direct ashing method), the organic material is burned and the combustion residue is measured by heating it at a high temperature until it becomes constant.

When the constituent material of the outer case 80 is a resin composition containing the resin as described above, the outer case 80 is manufactured by, for example, injection molding or the like.

<Release material>
As shown in FIGS. 2, 3 and 5, the release material 70 includes a part of the capacitor element 5, a part of the first external extraction terminal 61, and a part of the second external extraction terminal 62. It covers and. More specifically, the release material 70 covers a part of the surface of the first external electrode 51 and the second external electrode 52 located on the opening 81 side of the outer case 80. Further, the release material 70 covers the connection portion of the first external extraction terminal 61 with the first external electrode 51 and the connection portion of the second external extraction terminal 62 with the second external electrode 52. .. Here, when the first external extraction terminal 61 and the second external extraction terminal 62 are electrically connected to the first external electrode 51 and the second external electrode 52, respectively, via a solder layer. , The connection portion of the first external extraction terminal 61 with the first external electrode 51 and the connection portion of the second external extraction terminal 62 with the second external electrode 52 each include a solder layer.

The release material 70 is a connection portion between the first external electrode 51 and the first external electrode 51 in the first external extraction terminal 61, a second external electrode 52, and a second external extraction terminal 62. By covering the connection portion of 2 with the external electrode 52, the connection portion between the first external electrode 51 and the first external electrode 51 at the first external extraction terminal 61, and the second external electrode 52 , The connection portion of the second external extraction terminal 62 with the second external electrode 52 is less likely to be bound by the filling resin 90 described later. Therefore, even if the film capacitor 1 is moved to a low temperature environment or a high temperature environment, tensile stress is less likely to occur in the first external electrode 51 and the second external electrode 52. As a result, the occurrence of cracks in the first external electrode 51 and the second external electrode 52 is suppressed.

As shown in FIGS. 2 and 3, the release material 70 does not cover at least a part of the upper surface 10A of the laminated body 10. More specifically, the release material 70 does not cover a part of the upper surface 10A of the laminated body 10, or does not cover the entire upper surface 10A of the laminated body 10. The release material 70 has a first external extraction terminal 61 and a second external extraction terminal 61 when the capacitor element 5 with the first external extraction terminal 62 and the second external extraction terminal 62 is viewed from the upper surface 10A side of the laminated body 10. It does not have to cover the area connecting the drawer terminal 62. The width of such a region is preferably equal to or greater than the width of the smaller of the widths of the first external extraction terminal 61 and the second external extraction terminal 62.

Since the release material 70 does not cover at least a part of the upper surface 10A of the laminate 10, a part of the upper surface 10A comes into contact with the filling resin 90 described later. Therefore, the infiltration of water from the opening 81 of the outer case 80 into the upper surface 10A of the laminated body 10 is suppressed.

When the release material 70 does not cover a part of the upper surface 10A of the laminate 10, that is, covers a part of the upper surface 10A of the laminate 10, a part of the upper surface 10A of the laminate 10 covered with the release material 70. May be in close contact with the release material 70.

As shown in FIG. 3, the release material 70 does not have to cover at least a part of the lower surface 10B of the laminated body 10. More specifically, the release material 70 may not cover a part of the lower surface 10B of the laminated body 10, or may not cover the entire lower surface 10B of the laminated body 10. Since the release material 70 does not cover at least a part of the lower surface 10B of the laminate 10, a part of the lower surface 10B comes into contact with the filling resin 90 described later. Therefore, the infiltration of water from the opening 81 of the outer case 80 into the lower surface 10B of the laminated body 10 is suppressed.

As shown in FIGS. 2 and 5, the release material 70 may cover the side surface 10C of the laminate 10. By covering the side surface 10C of the laminate 10 with the release material 70, the release material 70 can be easily fixed. Further, since the side surface 10C of the laminated body 10 is less likely to be restrained by the filling resin 90 described later, the stress generated in the laminated body 10 when the film capacitor 1 is moved to a low temperature environment or a high temperature environment is relaxed.

Examples of the release material 70 include a biaxially stretched polypropylene film, a polyester adhesive tape (Mylar tape), and the like.

As an example of the method of providing the release material 70, the connection portion between the first external electrode 51 and the first external electrode 51 in the first external extraction terminal 61, the second external electrode 52, and the second external For example, a biaxially stretched polypropylene film is drawn from the first external drawing so as to cover the connection portion of the drawing terminal 62 with the second external electrode 52 and not to cover at least a part of the upper surface 10A of the laminated body 10. Examples thereof include a method of providing the capacitor element 5 with the terminal 61 and the second external extraction terminal 62 so as to be wound around the capacitor element 5. A specific example of the method of providing the release material 70 in this way will be described later.

In FIGS. 1, 2, 3, 4, and 5, a state in which a single capacitor element 5 is housed in a single exterior case 80 is illustrated, but is described in, for example, Patent Document 1. As described above, a plurality of capacitor elements 5 may be housed in a single exterior case 80. In this case, the release material 70 may be individually provided on the plurality of capacitor elements 5, or may be provided alone so as to bundle the plurality of capacitor elements 5.

The thickness of the release material 70 is preferably 12 μm or more and 50 μm or less.

The thickness of the release material 70 can be measured using an optical film thickness meter.

<Filling resin>
As shown in FIGS. 1, 3, 4, and 5, the filling resin 90 is filled in the outer case 80, and the capacitor element 5 is buried.

As shown in FIG. 5, the release material 70 is in at least in contact with the corner portion where the pair of side surfaces of the first external electrode 51 in the stacking direction T and the end surface in the width direction W intersect with the first external extraction terminal 61. However, it is at least not in contact with the end face of the first external electrode 51. Therefore, there is a region surrounded by the first external electrode 51, the first external extraction terminal 61, and the release material 70. Similarly, the release material 70 is in contact with at least the corner portion where the pair of side surfaces of the second external electrode 52 in the stacking direction T and the end surface in the width direction W intersect with the second external extraction terminal 62, and the second external electrode 52 is in contact with the second external electrode 52. At least not in contact with the end face of the external electrode 52. Therefore, there is a region surrounded by the second external electrode 52, the second external extraction terminal 62, and the release material 70. In such a state, since the filling resin 90 is filled from the opening 81 of the outer case 80, at least a part of the upper surface 10A of the laminate 10 not covered with the release material 70 is connected to the first external electrode 51. It enters the region surrounded by the first external extraction terminal 61 and the release material 70, and the region surrounded by the second external electrode 52, the second external extraction terminal 62, and the release material 70. Therefore, as shown in FIG. 5, in the film capacitor 1, the filled resin 90 is surrounded by the first external electrode 51, the first external extraction terminal 61, and the release material 70, and the second outer surface. It is provided in a region surrounded by the electrode 52, the second external extraction terminal 62, and the release material 70.

As described above, the release material 70 does not have to cover at least a part of the lower surface 10B of the laminate 10, but in this case, the filling resin 90 is the lower surface 10B of the laminate 10 not covered with the release material 70. A region surrounded by the first external electrode 51 and the release material 70 (a region in which the first external extraction terminal 61 is not provided), and a second external electrode 52 and the release material 70 from at least a part of the above. You may enter the area surrounded by (the area where the second external extraction terminal 62 is not provided).

The filling resin 90 is provided in the area surrounded by the first external electrode 51, the first external extraction terminal 61, and the release material 70, so that the first external electrode 51 comes into contact with the filling resin 90. Therefore, the infiltration of water from the opening 81 of the outer case 80 into the first external electrode 51 is suppressed.

The filling resin 90 is provided in the area surrounded by the second external electrode 52, the second external extraction terminal 62, and the release material 70, so that the second external electrode 52 comes into contact with the filling resin 90. Therefore, the infiltration of water from the opening 81 of the outer case 80 into the second external electrode 52 is suppressed.

Here, a region surrounded by the first external electrode 51, the first external extraction terminal 61, and the release material 70, and surrounded by the second external electrode 52, the second external extraction terminal 62, and the release material 70. Since the amount of the filling resin 90 provided in the region is small, the connection portion between the first external electrode 51 and the first external electrode 51 in the first external extraction terminal 61, and the second external electrode 52 And there is no influence to the extent that the connection portion between the second external extraction terminal 62 and the second external electrode 52 is restrained. Therefore, even if the film capacitor 1 is moved to a low temperature environment or a high temperature environment, tensile stress is less likely to occur in the first external electrode 51 and the second external electrode 52. As a result, while the generation of cracks in the first external electrode 51 and the second external electrode 52 is suppressed, the infiltration of water into the first external electrode 51 and the second external electrode 52 is suppressed as described above. Will be done.

Further, since the connection portion of the first external extraction terminal 61 with the first external electrode 51 and the connection portion of the second external extraction terminal 62 with the second external electrode 52 are small, in a conventional film capacitor, When a load is applied to the first external extraction terminal 61 and the second external extraction terminal 62, the first external extraction terminal 61 is separated from the first external electrode 51, and the second external extraction terminal 62 is the second. There is a risk of separation from the external electrode 52 of 2. On the other hand, in the film capacitor 1, the region surrounded by the first external electrode 51, the first external extraction terminal 61 and the release material 70, and the second external electrode 52 and the second external extraction terminal Since the filling resin 90 is provided in the region surrounded by the release material 70, the connection portion between the first external electrode 51 and the first external extraction terminal 61 is reinforced, and the second external electrode 52 and the second external electrode 52 are reinforced. The connection portion with the second external extraction terminal 62 is reinforced. As a result, even if a load is applied to the first external extraction terminal 61 and the second external extraction terminal 62, the first external extraction terminal 61 is suppressed from being separated from the first external electrode 51, and the second external extraction terminal 61 is prevented from being separated. Separation of the external extraction terminal 62 from the second external electrode 52 is suppressed.

Since the filling resin 90 is filled through the opening 81 of the outer case 80, it also enters the region between the release material 70 and the outer case 80. Therefore, as shown in FIG. 5, in the film capacitor 1, the filling resin 90 is provided in the region between the release material 70 and the outer case 80.

By providing the filling resin 90 in the region between the release material 70 and the outer case 80, the infiltration of water from the opening 81 of the outer case 80 into the entire capacitor element 5 is suppressed.

As shown in FIG. 5, the filling resin 90 may be provided in the region between the side surface 10C of the laminate 10 and the release material 70. By providing the filling resin 90 in the region between the side surface 10C of the laminated body 10 and the release material 70, the side surface 10C of the laminated body 10 comes into contact with the filling resin 90. Therefore, the infiltration of water from the opening 81 of the outer case 80 into the side surface 10C of the laminated body 10 is suppressed.

As the filling resin 90, it is preferable to appropriately select a resin having low moisture permeability from the viewpoint of suppressing the infiltration of water into the capacitor element 5, and examples thereof include epoxy resin, silicone resin, and urethane resin. Examples of the epoxy resin curing agent include amine curing agents and imidazole curing agents.

A reinforcing agent may be added to the filling resin 90 for the purpose of improving the strength. Examples of the reinforcing agent include silica, alumina and the like.

From the viewpoint of suppressing the infiltration of water into the capacitor element 5, it is preferable that the thickness of the filling resin 90 in the opening 81 of the outer case 80 is large. The thickness of the filling resin 90 in the opening 81 of the outer case 80 is preferably sufficiently large within an allowable range of the volume (physique) of the entire film capacitor 1, specifically, preferably 2 mm or more, more preferably 4 mm. That is all. In particular, by locating the capacitor element 5 on the bottom surface side of the exterior case 80 on the bottom surface side of the opening 81 side inside the exterior case 80, the thickness of the filling resin 90 with respect to the capacitor element 5 can be adjusted to the bottom surface on the opening 81 side of the exterior case 80. It is preferable to make it larger than the side.

The thickness of the filling resin 90 can be measured using a soft X-ray device if it is in a non-destructive state, and can be measured using a length measuring device such as a caliper if it is in a broken state.

The relationship between the height of the filling resin 90 and the height of the outer case 80 is such that the thickness of the filling resin 90 at the opening 81 of the outer case 80 may be made as large as possible, and may be up to the position on the inner side of the outer case 80. It may be full, or it may be slightly overflowed due to surface tension.

[Manufacturing method of film capacitors]
The film capacitor of the present invention is manufactured by, for example, the following method.

<Process for manufacturing capacitor elements>
First, for example, a resin solution is prepared by mixing the above-mentioned first organic material, second organic material, additives and the like. Then, the obtained resin solution is formed into a film and then heat-treated and cured to produce a first dielectric film and a second dielectric film.

Then, by depositing a metal such as aluminum, zinc, titanium, magnesium, tin, or nickel on one main surface of the first dielectric film to form a first metal layer, the first metal layer is formed. Make a metallized film. At this time, in the width direction, the first metal layer is formed so as to reach one side edge of the first metallized film and not reach the other side edge of the first metallized film.

Further, a second metal layer is formed by depositing a metal such as aluminum, zinc, titanium, magnesium, tin, or nickel on one main surface of the second dielectric film to form a second metal layer. Make a metallized film. At this time, the second metal layer is formed so as not to reach one side edge of the second metallized film in the width direction but to reach the other side edge of the second metallized film.

The second metal layer may be formed not on one main surface of the second dielectric film but on the other main surface of the first dielectric film. In this case, in this step, a metallized film in which the first metal layer is provided on one main surface of the first dielectric film and the second metal layer is provided on the other main surface. It will be manufactured. At this time, in the width direction, the first metal layer is formed so as to reach one side edge of the metallized film and not reach the other side edge of the metallized film, and one side edge of the metallized film is formed. The second metal layer may be formed so as to reach the other side edge of the metallized film without reaching.

Next, the first metallized film and the second metallized film are stacked in a state of being shifted by a predetermined distance in the width direction, and then wound to produce a laminated body (winding body). If necessary, the obtained laminate may be sandwiched from a direction perpendicular to the width direction and pressed into an elliptical cylinder shape.

Next, the first external electrode is connected to the first metal layer by spraying a metal such as zinc, aluminum, tin, or zinc-aluminum alloy onto one end face of the laminate. Form.

Further, the second external electrode is formed so as to be connected to the second metal layer by spraying a metal such as zinc, aluminum, tin, or zinc-aluminum alloy onto the other end face of the laminate. To do.

From the above, the capacitor element is manufactured.

<Process of providing an external lead-out terminal>
The first external lead-out terminal is provided so as to be connected to the first external electrode, for example, via a solder layer. Further, the second external extraction terminal is provided so as to be connected to the second external electrode via, for example, a solder layer. The constituent materials of the first external lead-out terminal and the second external lead-out terminal are, for example, metals such as copper, tin, and aluminum, respectively.

<Process of providing release material>
A connection portion between the first external electrode and the first external electrode at the first external extraction terminal, and a connection portion between the second external electrode and the second external electrode at the second external extraction terminal. For example, a biaxially stretched polypropylene film is provided so as to be wrapped around a capacitor element having a first external extraction terminal and a second external extraction terminal so as to cover and not cover at least a part of the upper surface of the laminate. Specific examples of the method of providing the release material in this way include the following two methods.

(First method)
First, the first method will be described with reference to FIGS. 8 and 9. 8 and 9 are schematic perspective views showing a first method for providing a release material in the method for manufacturing a film capacitor of the present invention.

As shown in FIG. 8, a shrink film 170 such as a biaxially stretched polypropylene film is formed into a tubular shape by heat-sealing the ends with a heat seal. The shrink film 170 will later become the release material 70. Further, the width G of the shrink film 170 is the direction of the capacitor element 5 in the direction orthogonal to the stacking direction T and the width direction W (in FIG. 8, the direction in which the first external extraction terminal 61 and the second external extraction terminal 62 extend). It is preferably larger than the length.

Then, as shown in FIG. 9, by inserting the capacitor element 5 with the first external extraction terminal 61 and the second external extraction terminal 62 into the tubular shrink film 170, the capacitor element 5 shrinks. The state is covered with the film 170.

After that, by shrinking the shrink film 170 by heat treatment, as shown in FIG. 2, the capacitor element 5 with the first external extraction terminal 61 and the second external extraction terminal 62 provided with the release material 70 is formed. obtain. More specifically, in the connection portion between the first external electrode 51 and the first external electrode 51 in the first external extraction terminal 61, the second external electrode 52, and the second external extraction terminal 62. The release material 70 is provided so as to cover the connection portion with the second external electrode 52 and not to cover at least a part of the upper surface 10A of the laminated body 10.

The release material 70 has traces of the heat seal of the shrink film 170 as described above. The trace of such a heat seal exists in the release material 70 at a position facing the side surface 10C of the laminated body 10, for example. Further, the shape of the heat seal may be point-shaped or planar.

(Second method)
Next, the second method will be described with reference to FIGS. 10 and 11. 10 and 11 are schematic perspective views showing a second method for a step of providing a release material in the method for manufacturing a film capacitor of the present invention.

As shown in FIG. 10, one end of a shrink film 170 such as a biaxially stretched polypropylene film is fixed to the side surface 10C of the laminated body 10 of the capacitor element 5 by heat fusion by heat sealing. The shape of the heat seal may be point-shaped or planar. Further, the width G of the shrink film 170 is the direction of the capacitor element 5 in the direction orthogonal to the stacking direction T and the width direction W (in FIG. 10, the direction in which the first external extraction terminal 61 and the second external extraction terminal 62 extend). It is preferably larger than the length.

Then, as shown in FIG. 11, the shrink film 170 is wound around the capacitor element 5 with the first external extraction terminal 61 and the second external extraction terminal 62 so as to cover the capacitor element 5. At this time, the shrink film 170 may be wound for one round or for two or more turns. After winding the shrink film 170, the other end of the shrink film 170 is fixed to a part of the shrink film 170, for example, a position facing the side surface 10C of the laminate 10 in the shrink film 170 by heat fusion by heat sealing. .. The shape of the heat seal may be point-shaped or planar.

<Process of storing the capacitor element in the outer case>
First, an exterior case having an opening at one end is produced by injection molding using a resin composition containing a highly insulating resin such as polybutylene terephthalate, polyphenylene sulfide, and a liquid crystal polymer. Alternatively, an outer case having an opening at one end may be produced by impact molding using a metal such as aluminum, magnesium, iron, stainless steel, or copper, or an alloy thereof.

Then, the capacitor element with the first external extraction terminal and the second external extraction terminal provided with the release material is housed inside the outer case.

<Process of filling filling resin>
A filling resin such as an epoxy resin, a silicone resin, or a urethane resin is filled through the opening of the outer case, and the capacitor element is buried. At this time, the filling resin is formed from at least a part of the upper surface of the laminate not covered with the release material, a region surrounded by the first external electrode, the first external extraction terminal, and the release material, and the second. It enters the area surrounded by the external electrode, the second external extraction terminal, and the release material. The filling resin also enters the area between the release material and the outer case. Therefore, the filling resin contains a region surrounded by the first external electrode, the first external extraction terminal, and the release material, a region surrounded by the second external electrode, the second external extraction terminal, and the release material, and It will be provided in the area between the release material and the outer case.

From the above, the film capacitor of the present invention is manufactured.

Hereinafter, an example in which the film capacitor of the present invention is disclosed more specifically will be shown. The present invention is not limited to these examples.

[Example 1]
The film capacitor of Example 1 was manufactured by the following method.

<Process for manufacturing capacitor elements>
First, a resin solution was prepared by mixing phenoxy resin, which is a bisphenol A type epoxy resin as a first organic material, and diphenylmethane diisocyanate, which is a second organic material, at a weight ratio of 7: 3. Then, the obtained resin solution was formed into a film and then heat-treated and cured to prepare a first dielectric film and a second dielectric film. The thickness of the first dielectric film and the second dielectric film was 3 μm.

Then, aluminum was vapor-deposited on one main surface of the first dielectric film to form the first metal layer, thereby producing the first metallized film. At this time, in the width direction, the first metal layer was formed so as to reach one side edge of the first metallized film and not reach the other side edge of the first metallized film. The thickness of the first metal layer was 20 nm.

Further, a second metallized film was produced by depositing aluminum on one main surface of the second dielectric film to form a second metal layer. At this time, the second metal layer was formed so as not to reach one side edge of the second metallized film in the width direction but to reach the other side edge of the second metallized film. The thickness of the second metal layer was 20 nm.

Next, the first metallized film and the second metallized film were laminated in a state of being shifted by a predetermined distance in the width direction, and then wound to prepare a laminated body (winding body). Then, the obtained laminate was sandwiched from a direction perpendicular to the width direction and pressed into an elliptical cylinder shape.

Next, zinc was sprayed onto one end face of the laminate to form a first external electrode so as to be connected to the first metal layer.

Further, the second external electrode was formed so as to be connected to the second metal layer by spraying zinc on the other end face of the laminated body.

From the above, the capacitor element was manufactured.

<Process of providing an external lead-out terminal>
The first external lead-out terminal is provided so as to be connected to the first external electrode via a solder layer. Further, the second external lead-out terminal is provided so as to be connected to the second external electrode via the solder layer. The first external lead-out terminal and the second external lead-out terminal were each made of copper and had a tin-plated surface.

<Process of providing release material>
According to the first method described above, the connection portion between the first external electrode and the first external electrode in the first external extraction terminal, the second external electrode, and the second in the second external extraction terminal. A biaxially stretched polypropylene film as a release material is provided as a first external extraction terminal and a second external extraction terminal so as to cover the connection portion with the external electrode and not to cover at least a part of the upper surface of the laminate. It was provided in the attached capacitor element. The heat treatment for shrinking the shrink film was carried out at 120 ° C. for 3 seconds using a hot air gun or a dryer. The thickness of the release material was 50 μm.

<Process of storing the capacitor element in the outer case>
First, using a liquid crystal polymer, an outer case having an opening at one end was produced by injection molding.

Then, a capacitor element with a first external extraction terminal and a second external extraction terminal provided with a release material was housed inside the outer case.

<Process of filling filling resin>
An epoxy resin as a filling resin was filled through the opening of the outer case, and the capacitor element was buried. At this time, the filling resin is formed from at least a part of the upper surface of the laminate not covered with the release material, a region surrounded by the first external electrode, the first external extraction terminal, and the release material, and the second. It entered the area surrounded by the external electrode, the second external extraction terminal, and the release material. The filling resin also entered the area between the release material and the outer case. Therefore, the filling resin contains a region surrounded by the first external electrode, the first external extraction terminal, and the release material, a region surrounded by the second external electrode, the second external extraction terminal, and the release material, and It was provided in the area between the release material and the outer case.

As described above, the film capacitor of Example 1 was manufactured for 5 samples.

[Comparative Example 1]
A film capacitor of Comparative Example 1 was produced for 5 samples in the same manner as the film capacitor of Example 1 except that the step of providing the release material was not performed.

[Evaluation]
The film capacitors of Example 1 and Comparative Example 1 were subjected to a heat cycle test in a temperature range of −40 ° C. or higher and 125 ° C. or lower. In the heat cycle test, one cycle was defined as a cycle in which the film capacitor was transferred from a low temperature environment of −40 ° C. to a high temperature environment of 125 ° C. and then from a high temperature environment of 125 ° C. to a low temperature environment of −40 ° C. Then, the rate of change of the equivalent series resistance (ESR) at a predetermined number of cycles was measured as an index for evaluating the degree of crack occurrence in the first external electrode and the second external electrode. FIG. 12 is a graph showing the measurement results of the rate of change of the equivalent series resistance with respect to the film capacitors of Example 1 and Comparative Example 1. In FIG. 12, five samples of the film capacitor of Example 1 are used in "Example 1-1", "Example 1-2", "Example 1-3", "Example 1-4", and "Example 1-4". It is shown as "Example 1-5". Further, 5 samples of the film capacitor of Comparative Example 1 were used as "Comparative Example 1-1", "Comparative Example 1-2", "Comparative Example 1-3", "Comparative Example 1-4", and "Comparative Example 1". It is shown as -5 ".

Regarding the rate of change of the equivalent series resistance, the equivalent series resistance before and after the heat cycle test at a predetermined number of cycles was measured using the LCR meter "ZM2371" manufactured by NF Circuit Design Block, and based on the following formula (F). Calculated. The measurement conditions for the equivalent series resistance were a measurement frequency of 10 kHz and a measurement voltage of 2 V.
100 x ["Equivalent series resistance after heat cycle test"-"Equivalent series resistance before heat cycle test"] / "Equivalent series resistance before heat cycle test" (F)

As shown in FIG. 12, in the film capacitor of Example 1, the equivalent series resistance is stable even if the number of cycles is increased, and the occurrence of cracks in the first external electrode and the second external electrode is suppressed. It turned out that. On the other hand, in the film capacitor of Comparative Example 1, it was found that the rate of change of the equivalent series resistance increased as the number of cycles increased, and the occurrence of cracks in the first external electrode and the second external electrode was not suppressed. It was.

1 Film capacitor 5 Capacitor element 10 Laminated body 10A Upper surface of laminated body 10B Lower surface of laminated body 10C Side surface of laminated body 21 First metallized film 22 Second metallized film 31 First dielectric film 32 Second dielectric Body film 41 First metal layer 42 Second metal layer 51 First external electrode 52 Second external electrode 61 First external extraction terminal 62 Second external extraction terminal 70 Release material 80 Exterior case 81 Exterior case Opening 90 Filling resin 170 Shrink film G Shrink film width T Lamination direction W Width direction

Claims

A film containing a metallized film having a metal layer provided on the main surface of the dielectric film is laminated in the laminating direction, and the laminated body is provided on both end faces of the laminated body in a width direction orthogonal to the laminating direction. A capacitor element having a pair of external electrodes and
An external lead-out terminal connected to the external electrode and
A release material that covers a part of the capacitor element and a part of the external extraction terminal,
An exterior case with an opening at one end to house the capacitor element inside,
A filling resin, which is filled in the outer case and buries the capacitor element, is provided.
The laminate has an upper surface located on the opening side of the exterior case.
The release material covers the connection portion of the external extraction terminal with the external electrode and the external electrode, and does not cover at least a part of the upper surface of the laminated body.
The film capacitor is provided in a region surrounded by the external electrode, the external extraction terminal, and the release material, and a region between the release material and the exterior case.
The laminated body has a lower surface facing the upper surface and has a lower surface facing the upper surface.
The film capacitor according to claim 1, wherein the release material does not cover at least a part of the lower surface of the laminate.
The film capacitor according to claim 1 or 2, wherein the release material covers the side surface of the laminate.