JP2020136518A - Capacitor and manufacturing method of capacitor - Google Patents

Abstract

To provide a capacitor achieving weight saving and having excellent moisture resistance.SOLUTION: A capacitor 10 includes: a capacitor element 1; and a pair of metallicon electrodes 2 provided to both ends of the capacitor element. The pair of metallicon electrodes cover the boundary between both end surfaces and the side surface of the capacitor element. The capacitor element preferably includes: a body 11; and an exterior material 12 that covers at least part of the side of the body, and further preferably includes a metal foil 4 covering at least part of the capacitor element.SELECTED DRAWING: Figure 1

Description

The present disclosure relates generally to a capacitor and a method of manufacturing a capacitor, and more particularly to a capacitor including a capacitor element and a method of manufacturing a capacitor including a capacitor element.

Capacitors are passive components that store and release electric charges and are used as components in electronic devices. Since a capacitor may be defective due to moisture absorption, a capacitor having excellent moisture resistance is required. For example, Patent Document 1 discloses a case-molded capacitor in which a capacitor is housed in a resin case and the case is filled with an insulating mold resin.

Japanese Unexamined Patent Publication No. 2008-25159

In Patent Document 1, although a film capacitor having a certain degree of moisture resistance can be obtained, weight reduction is not considered.

An object of the present disclosure is to provide a capacitor and a method for manufacturing a capacitor, which realizes weight reduction and has excellent moisture resistance.

The capacitor according to one aspect of the present disclosure includes a capacitor element and a pair of metallikon electrodes provided on both end faces of the capacitor element, and the pair of metallikon electrodes includes both end faces and side surfaces of the capacitor element. Cover the boundary of the.

The method for manufacturing a capacitor according to one aspect of the present disclosure includes a step of forming a pair of metallikon electrodes covering both end faces and side surfaces of the capacitor element on both end faces of the capacitor element.

According to the present disclosure, it is possible to provide a capacitor having excellent moisture resistance while realizing weight reduction.

FIG. 1A is a schematic cross-sectional view of a capacitor according to an embodiment of the present disclosure. FIG. 1B is a schematic cross-sectional view of a capacitor according to another embodiment of the present disclosure. FIG. 2 is a perspective view of a capacitor according to an embodiment of the present disclosure.

1. 1. Overview As shown in FIGS. 1A and 1B, the capacitor 10 according to the present embodiment includes a capacitor element 1 and a pair of metallikon electrodes 2 (21, 22) provided on both end faces of the capacitor element 1. The pair of metallikon electrodes 2 (21, 22) covers the boundary between both end faces and the side surfaces of the capacitor element 1.

The capacitor 10 does not include an outer case as described in Patent Document 1 and a mold resin filled in the outer case. That is, the capacitor 10 adopts a so-called caseless structure. Therefore, the capacitor 10 can be reduced in weight by at least the amount corresponding to the conventional outer case.

Further, the capacitor 10 includes a pair of metallikon electrodes 2 (21, 22) that cover the boundary between both end faces and the side surfaces of the capacitor element 1. Therefore, as compared with the case where the metallikon electrodes are formed only on both end faces of the capacitor element, it is possible to prevent gas such as water vapor from entering from the boundary between both end faces and the side surface of the capacitor element 1, and the capacitor element can be prevented from entering. It becomes easy to prevent the moisture absorption of 1. This makes it possible to prevent the capacitor 10 from being deteriorated by a gas such as water vapor.

2. 2. Details Hereinafter, the capacitor 10 according to the present embodiment will be described in detail with reference to FIGS. 1A, 1B, and 2. FIG. 2 is a perspective view of the capacitor 10 according to the present embodiment. FIG. 1A is a cross-sectional view of the capacitor 10 at the cutting line XX of FIG. FIG. 1B is a modification of the capacitor 10 shown in FIG. 1A.

The capacitor 10 according to the present embodiment adopts a so-called caseless structure, and does not have an exterior case as described in Patent Document 1. That is, the capacitor 10 is a caseless capacitor. As shown in FIGS. 1A and 1B, the capacitor 10 includes a capacitor element 1 and a pair of metallikon electrodes 2 (21, 22) provided on both end faces of the capacitor element 1.

First, the metallikon electrode 2 (21, 22) will be described. As shown in FIGS. 1A and 1B, the metallikon electrodes 2 are provided on both end faces of the capacitor element 1, and the first conductive layer (first internal electrode) and the second conductive layer (second conductive layer) of the capacitor element 1 described later. It is electrically connected to the internal electrode). That is, the capacitor 10 has a pair of metallikon electrodes 21 and 22. The both end faces of the capacitor element 1 mean the end faces formed by the cross sections of the plurality of first metallized films and the plurality of second metallized films in the capacitor element 1 described later. Further, the side surface of the capacitor element means a peripheral surface connecting the end faces of the capacitor element 1.

The metallikon electrodes 2 (21, 22) cover the boundary between both end faces and the side surfaces of the capacitor element 1. As shown in FIGS. 1A and 1B, the metallikon electrode 21 of the pair of metallicon electrodes 2 is formed on one end face of the capacitor element 1, and the metallikon electrode 22 is formed on the other end face of the capacitor element 1. The metallikon electrodes 2 (21, 22) cover the entire circumference of the boundary between both end faces and the side surfaces of the capacitor element 1 and are formed in a cap shape. Both end faces of the capacitor element 1 include a plurality of cross sections of the first metallized film and the second metallized film, as will be described later. Therefore, simply forming the metallikon electrode 2 on both end faces of the capacitor element 1 may allow gas such as water vapor to enter between the boundary between both end faces and the side surface of the metallikon electrode and the capacitor element 1. If water or gas enters from such a place, the water or gas reaches the cross section of the first metallized film and the second metallized film, causing a defect in the capacitor 10 or shortening the life of the capacitor 10. There is a risk of However, as shown in FIGS. 1A and 1B, by covering the boundary between both end faces and the side surfaces of the capacitor element 1 with the metallikon electrode, it is possible to prevent the intrusion of gas and moisture from this boundary, and the capacitor. Moisture resistance of 10 can be improved.

The pair of metallikon electrodes 2 (21, 22) are formed so as not to come into contact with each other. That is, the metallikon electrode 21 and the metallicon electrode 22 are formed so as not to come into contact with each other. As will be described later, the metallikon electrode 2 is formed by metallikon (metal spraying). Therefore, for example, the portion of the side surface of the capacitor element 1 that is not covered with the metallikon electrode 2 is masked with an adhesive tape or the like, the metal is sprayed, and then the masking is removed. The 22 can be formed so that they do not come into contact with each other. Thereby, a short circuit defect can be prevented. The shortest distance A between the end on the side surface of the capacitor element 1 of the metallikon electrode 21 and the end on the side surface of the capacitor element 1 of the metallikon electrode 22 is preferably 10 mm or more. In this case, it becomes easier to prevent the metallikon electrodes 21 and 22 from coming into contact with each other and causing a short circuit failure. The shortest distance A between the end on the side surface of the capacitor element 1 of the metallikon electrode 21 and the end on the side surface of the capacitor element 1 of the metallikon electrode 22 is more preferably 20 mm or more.

The distance B between the end on the side surface of the capacitor element 1 of the metallikon electrode 2 and the boundary between the end surface and the side surface of the capacitor element 1 is preferably 2.5 mm or more. That is, it is preferable that the metallikon electrode 2 covers the entire circumference of the side surfaces on both ends of the capacitor element 1 with a width of 2.5 mm or more. In this case, it becomes easier to prevent gas and moisture from entering from the boundary between both end faces and the side surfaces of the capacitor element 1. The distance B between the end of the metallikon electrode 2 on the side surface of the capacitor element 1 and the boundary between the end surface and the side surface of the capacitor element 1 is more preferably 5.0 mm or more.

The metallikon electrode 2 is an external electrode formed by metallikon (metal spraying). The metallikon electrode 2 is formed by the metallikon so as to cover both end faces of the capacitor element 1 with a boundary portion between both end faces and side surfaces of the capacitor element 1. The metallikon electrode 2 is electrically connected to the first conductive layer (first internal electrode) and the second conductive layer (second internal electrode) of the capacitor element 1.

For example, when a winding type capacitor element described later is used, a pair of metallikon electrodes 21 and 22 are formed by metallikons on two surfaces located at both ends of the flattened winding type capacitor element. The two surfaces located at both ends of the wound capacitor element include a cross section of a first metallized film and a plurality of second metallized films. Therefore, by forming the metallikon electrodes 21 and 22 on the two surfaces located at both ends of the wound capacitor element, the metallikon electrodes 21 and 22 and the first conductive layer (first internal electrode) and the second conductive layer (first) are formed. 2 Internal electrodes) can be electrically connected to each other.

On the other hand, when a laminated capacitor element described later is used, a pair of metallikon electrodes 21 and 22 are formed by a metallikon on a pair of surfaces having a cross section of a plurality of first metallized films and a plurality of second metallized films. The pair of surfaces means that the two surfaces are located at both ends of the laminated capacitor element. The two surfaces located at both ends of the laminated capacitor element are composed of a plurality of first metallized films and a plurality of cross sections of the second metallized films. Therefore, by forming the metallikon electrodes 21 and 22 on the two surfaces located at both ends of the laminated capacitor element, the metallikon electrodes 21 and 22 and the first conductive layer (first internal electrode) and the second conductive layer (second conductive layer) are formed. Internal electrodes) can be electrically connected to each other.

The method of metallikon (metal spraying) is not particularly limited, and for example, a plasma spraying method, a frame spraying method, and an arc spraying method can be used. When forming the metallikon electrode 2, it is preferable to use a plasma spraying method and a frame spraying method. In this case, the homogeneity of the formed metallikon electrode 2 layer can be enhanced, and moisture and gas can be made difficult to permeate. Further, in the plasma spraying method and the frame spraying method, the temperature of the metal material used as the material of the metallikon electrode 2 can be raised, so that the metallikon electrode 2 can be easily formed on the side surface of the capacitor element 1 and the capacitor element can be easily formed. The adhesion between 1 and the metallikon electrode 2 tends to be high. This is because by raising the temperature of the metal material, when the metal material adheres to the side surface of the capacitor element 1, the side surface of the capacitor element 1 is slightly melted by the heat of the hot metal material that has been sprayed, and the capacitor element 1 It is considered that this is because the metal material enters the unevenness due to the occurrence of minute irregularities on the side surface of the capacitor element 1 and the adhesion to the side surface of the capacitor element 1 is improved. The temperature of the metal material when forming the metallikon electrode 2 is preferably higher than the melting point of the material on the side surface of the capacitor element 1. Further, as described later, when the capacitor element 1 has the exterior material 12, the temperature of the metal material is preferably higher than the melting point of the exterior material 12. As a result, the adhesion between the metallikon electrode 2 and the side surface of the capacitor element 1 can be further improved.

The temperature of the metal material when forming the metallikon electrode 2 is preferably 1200 ° C. or lower. In this case, it becomes easy to prevent defects from occurring on both end faces of the capacitor element 1 due to the heat of the sprayed metal material. The temperature of the metal material when forming the metallikon electrode 2 is more preferably 1000 ° C. or lower.

The material of the metallikon electrode 2 is not particularly limited, and includes, for example, zinc, copper, and aluminum. The metallikon electrode 2 may be formed of only one kind of metal, or may be formed of a mixture of two or more kinds of metals.

Next, the capacitor element 1 will be described. The capacitor element 1 has a plastic film as a dielectric. The capacitor element 1 may be a winding type capacitor element or a laminated type capacitor element. An example of a winding type capacitor element and a laminated type capacitor element is shown below.

The winding type capacitor element can be manufactured, for example, as follows. First, a first metallized film having a first dielectric film and a first conductive layer and a second metallized film having a second dielectric film and a second conductive layer are prepared. The first dielectric film and the second dielectric film are long products. A first conductive layer is formed on one side of the first dielectric film. Further, a second conductive layer is formed on one side of the second dielectric film.

The first dielectric film and the second dielectric film are made of, for example, polypropylene, polyethylene terephthalate, polyethylene naphthalate, polyphenyl sulfide, polystyrene, or the like. The first conductive layer and the second conductive layer are formed by a method such as a vapor deposition method or a sputtering method. The first conductive layer and the second conductive layer are made of, for example, aluminum, zinc, magnesium, or the like.

Next, two of each of the first metallized film and the second metallized film so that the first dielectric film or the second dielectric film is interposed between the first conductive layer and the second conductive layer. Align the long sides and stack them. By winding the first metallized film and the second metallized film in a stacked state in this way, a columnar wound body can be obtained. Next, the side surfaces of the winding body are pressed from both sides to process the winding body having an oval cross section. Thereby, a winding type capacitor element can be obtained. Both end faces of the wound body having an elongated cross section are surfaces composed of cross sections of a plurality of first metallized films and a plurality of second metallized films, and these surfaces are both end surfaces of the capacitor element 1. By flattening the capacitor element in this way, space can be saved. The side surface of the wound capacitor element may be covered with, for example, a protective film having electrical insulation. Further, the first dielectric film in the first metallized film located on the outermost layer on the side surface of the wound body may function as a protective film.

On the other hand, the laminated capacitor element can be manufactured, for example, as follows. First, a first metallized film having a first dielectric film and a first conductive layer and a second metallized film having a second dielectric film and a second conductive layer are prepared. The first dielectric film and the second dielectric film have a rectangular shape having the same size. A first conductive layer is formed on one side of the first dielectric film. Further, a second conductive layer is formed on one side of the second dielectric film.

The first dielectric film and the second dielectric film are made of, for example, polypropylene, polyethylene terephthalate, polyethylene naphthalate, polyphenyl sulfide, polystyrene, or the like. The first conductive layer and the second conductive layer are formed by a method such as a vapor deposition method or a sputtering method. The first conductive layer and the second conductive layer are made of, for example, aluminum, zinc, magnesium, or the like.

Next, the four sides of the first metallized film and the second metallized film are aligned so that the first dielectric film or the second dielectric film is interposed between the first conductive layer and the second conductive layer. Stack alternately. In this way, a laminated body can be obtained by laminating and integrating a plurality of first metallized films and second metallized films. The laminate may be coated with, for example, a protective film having electrical insulation, except for a pair of surfaces on which the external electrodes are formed. When the capacitor element 1 is a laminated capacitor element, the surface other than the pair of surfaces on which the external electrode is formed is referred to as the side surface of the capacitor element 1. In this laminated body, the external electrode is formed on a surface formed by a cross section of a plurality of first metallized films and a plurality of second metallized films. As a result, a laminated capacitor element can be obtained.

A winding type capacitor element or a laminated type capacitor element may be used as it is as the capacitor element 1. Further, the capacitor element 1 may be obtained by using the wound capacitor element and the laminated capacitor element as the main body 11 of the capacitor element 1 and covering at least a part of the side surface of the main body 11 with the exterior material 12. The capacitor element 1 preferably includes a main body 11 and an exterior material 12 that covers at least a part of the side surface of the main body 11. The exterior material 12 has an electrical insulating property. The exterior material 12 is preferably in the form of a film.

The exterior material 12 preferably covers a portion of the side surface of the main body 11 that is covered with the metallikon electrode 2. That is, it is preferable that the exterior material 12 covers the entire circumference of the side surfaces of the main body 11 on both end faces. In this case, since the metallikon electrode 2 is not directly formed on the side surface of the main body 11 but is formed on the exterior material 12, it is easy to improve the adhesion between the metallikon electrode 2 and the side surface of the capacitor element 1.

As described above, the side surfaces of the wound capacitor element and the laminated capacitor element may be coated with a protective film (not shown) having electrical insulation. That is, the side surface of the main body 11 of the capacitor element 1 may be covered with a protective film. In this case, at least a part of the side surface of the main body 11 may be covered with the exterior material 12 from above the protective film. The material of the protective film is not particularly limited as long as it is a film having electrical insulation.

A case where the entire side surface of the main body 11 is covered with the exterior material 12 will be described. As shown in FIG. 1A, the exterior material 12 may cover the entire side surface of the main body 11. In this case, the side surface of the main body 11 may or may not be covered with the protective film. When the side surface of the main body 11 is covered with the protective film, the exterior material 12 covers the side surface of the main body 11 from above the protective film. When the side surface of the main body 11 is not covered with the protective film, the exterior material 12 directly covers the side surface of the main body 11, that is, the side surface of the wound capacitor element or the laminated capacitor element, and therefore also functions as a protective film. ..

Next, a case where a part of the side surface of the main body 11 is covered with the exterior material 12 will be described. As shown in FIG. 1B, the exterior material 12 may cover the portion covered by the metallikon electrode 2 on the side surface of the main body 11. That is, the exterior material 12 (121, 122) may cover the entire circumference of the side surface on both end faces of the main body 11. In FIG. 1B, the exterior material 121 covers the side surface on the side where the metallikon electrode 21 is formed, and the exterior material 122 covers the side surface on the side where the metallikon electrode 22 is formed. In this case, the side surface of the main body 11 may or may not be covered with the protective film. However, from the viewpoint of preventing short-circuit defects, it is preferable that at least the portion of the side surface of the main body 11 that is not covered with the exterior material 12 is covered with a protective film. That is, for example, the entire side surface of the main body 11 may be covered with a protective film, and then the side surfaces on both end faces of the main body 11 may be further covered with the exterior material 12, and the portion of the side surface of the main body 11 other than the end surface sides may be covered. After covering with a protective film, the side surfaces on both end faces may be covered with the exterior material 12.

As shown in FIG. 1B, the width C of the side surfaces of the main body 11 covered by the exterior material 12 on both end faces is preferably larger than the width B of the side surfaces of the capacitor element 11 covered by the metallikon electrode 2. .. In this case, it becomes easy to improve the adhesion between the metallikon electrode 2 and the side surface of the capacitor element 1.

The material of the exterior material 12 is not particularly limited, and may be made of a material having electrical insulation. Examples of materials for exterior material 12 include polypropylene, polyethylene, polyethylene terephthalate (PET), polybutadiene, and nylon.

When the side surface of the main body 11 is covered with a protective film, the melting point of the exterior material 12 is preferably lower than the melting point of the protective film. In this case, as described above, when the metallikon electrode 2 is formed on the side surface of the capacitor element 1 by thermal spraying, the surface of the exterior material 12 is easily melted by the heat of the sprayed metal, and the capacitor element 1 and the metallikon are easily melted. Adhesion with the electrode 2 tends to be high. Further, since the melting point of the protective film is also high in the exterior material 12, even if the surface of the exterior material 12 is melted by heat, the surface of the protective film is difficult to melt, and the heat causes a defect in the capacitor element 1. It becomes easier to prevent.

The exterior material 12 is preferably in the form of a film. In this case, the main body 11 can be easily covered with the exterior material 12.

The exterior material 12 is preferably formed of a non-stretched film. In this case, since the adhesion between the metallikon electrode 2 and the exterior material 12 is further improved, the adhesion between the metallikon electrode 2 and the side surface of the capacitor element 1 is enhanced, and it becomes easier to prevent the permeation of moisture and gas. As described above, when the entire side surface of the main body 11 is covered with the exterior material 12, the entire side surface of the main body 11 may be covered with an unstretched film, and a part of the film is stretched by biaxial stretching or the like. , A film in which a part of the film is not stretched and is left unstretched may be used. When a partially unstretched film is used as described above, it is preferable that the portion of the side surface of the main body 11 covered by the metallikon electrode 2 is covered with the unstretched film. For example, only the central portion is stretched without stretching both ends of a long film having the same length as the capacitor element 1, and the unstretched portions at both ends of the film are located on both ends of the capacitor element 1. By wrapping the film around the side surface of the main body 11 as described above, the main body 11 can be covered with the exterior material 12.

The exterior material 12 is preferably roughened. In this case, since the adhesion between the metallikon electrode 2 and the exterior material 12 is further improved, the adhesion between the metallikon electrode 2 and the side surface of the capacitor element 1 is enhanced, and it becomes easier to prevent the permeation of moisture and gas. The roughening method is not particularly limited, and for example, a blast method and an etching method can be used. After the film used as the exterior material 12 is roughened in advance, it may be wound around the main body 11 to cover the main body 11. Further, after covering the main body 11 with the exterior material 12, the side surface of the exterior material 12 (that is, the side surface of the capacitor element 1) may be roughened. As described above, when the entire side surface of the main body 11 is covered with the exterior material 12, the entire side surface of the main body 11 may be covered with the roughened film, and after the main body 11 is covered with the exterior material 12, The entire exterior material 12 may be roughened. Further, the entire side surface of the main body 11 may be covered with a partially roughened film, or only a part of the exterior material 12 may be roughened after the main body 11 is covered with the exterior material 12. .. When a partially roughened film is used, it is preferable that the portion covered by the metallikon electrode 2 on the side surface of the main body 11 is covered with the roughened film. For example, the main body of the film is such that only both ends of a long film having the same length as the capacitor element 1 are roughened, and the roughened portions at both ends of the film are located on both ends of the capacitor element 1. By wrapping around the side surface of 11, the main body 11 can be covered with the exterior material 12. Of course, after covering the entire side surface of the main body 11 with the exterior material 12, only the side surfaces on both ends on which the metallikon electrode 2 is formed may be roughened.

It is preferable that the capacitor 10 further includes a metal foil 4 that covers at least a part of the capacitor element 1. By covering at least a part of the surface of the capacitor element 1 with the metal foil 4, it becomes easy to prevent moisture absorption from the surface of the capacitor element 1.

The type of the metal foil 4 is not particularly limited, and any metal foil 4 may be used as long as it is less likely to allow moisture or gas such as water vapor to permeate than the metallikon electrode 2. When the capacitor element 1 has the exterior material 12, it is preferable to use a material that is less likely to allow moisture or gas such as water vapor to permeate than the exterior material 12. When the main body 11 of the capacitor element 1 has a protective film, it is preferable to use a material that is less likely to allow moisture or gas such as water vapor to permeate than the protective film. Specific examples of the material of the metal leaf 4 include copper, aluminum, iron, stainless steel, magnesium, silver, gold, nickel, and platinum. As the metal foil 4, a metal foil with a resin having a resin layer provided on one side of the metal foil may be used.

It is preferable that the capacitor 10 further includes an insulating protective material 5 provided between the capacitor element 1 and the metal foil 4. By covering the capacitor element 1 with the metal foil 4 and further covering it with the insulating protective material 5, it becomes easier to prevent moisture absorption from the surface of the capacitor element 1.

The material of the insulating protective material 5 is not particularly limited, and may be any material having insulating properties. As the material of the insulating protective material 5, it is preferable to use a material that is less likely to allow moisture or gas such as water vapor to permeate than the metallikon electrode 2. In this case, the moisture resistance of the capacitor 10 can be further improved. When the capacitor element 1 has the exterior material 12, it is preferable to use a material that is less likely to allow moisture or gas such as water vapor to permeate than the exterior material 12. When the main body 11 of the capacitor element 1 has a protective film, it is preferable to use a material that is less likely to allow moisture or gas such as water vapor to permeate than the protective film.

The insulating protective material 5 preferably contains at least one selected from the group consisting of an insulating film, a gas barrier film, and a cured product of a prepreg. In this case, it becomes easier to prevent moisture absorption from the surface of the capacitor element 1, and the moisture resistance of the capacitor 10 can be further improved.

The insulating film is not particularly limited as long as it is a film having insulating properties. Specific examples of the material of the insulating film include polypropylene, polyethylene, polyimide and the like.

The gas barrier film is not particularly limited as long as it has an insulating property and has a property of making it difficult for a gas such as water vapor to permeate. As the gas barrier film, a film having a base film and a gas barrier layer formed on the base film can be used. The base film is not particularly limited, and is, for example, a polyethylene terephthalate (PET) film (melting point 265 ° C., glass transition point 80 ° C. (TMA method)), a polyphenylene sulfide (PPS) film (melting point 280 ° C., glass transition point 100 ° C.). ), Polyetheralphon (PES) film (glass transition point 220 ° C), polyetherimide (PEI) film (glass transition point 220 ° C), and polyetheretherketone (PEEK) film (melting point 340 ° C, glass transition point). 140 ° C.) and the like can be used. Since these films are also excellent in heat resistance, the heat resistance of the capacitor 10 can be improved. The above melting point and glass transition point are data obtained by the DSC method (heating rate: 10 ° C./min). The gas barrier layer is not particularly limited, and includes, for example, at least one of silicon oxide and aluminum oxide. The gas barrier layer can be formed by, for example, a vapor deposition method, a sputtering method, a plasma CVD method, or the like.

A cured product of the prepreg means that the prepreg is completely cured and is in the C-stage state. The C-stage is an insoluble and insoluble state, which is the final state of the curing reaction. The prepreg contains a reinforcing material and a thermosetting resin composition.

The reinforcing material is not particularly limited, and may be, for example, an organic fiber or an inorganic fiber woven fabric or a non-woven fabric. Specific examples of the reinforcing material include a glass cloth and a non-woven fabric of PET fibers.

The thermosetting resin composition is not particularly limited, and a composition containing a thermosetting resin that is liquid at room temperature (25 ° C.) before the curing reaction can be used. The thermosetting resin is not particularly limited, and examples thereof include an epoxy resin, an unsaturated polyester resin, and a polyimide resin. Of these, epoxy resin is preferred. Epoxy resin is excellent in properties such as heat resistance, chemical resistance, toughness, electrical insulation and adhesiveness. The curing temperature of the thermosetting resin composition is preferably 120 ° C. or lower. In this case, the influence of heat on the capacitor element 1 when curing the prepreg can be reduced. The thermosetting resin composition may contain an inorganic filler. The inorganic filler is not particularly limited, and examples thereof include silica, alumina, silicon nitride, boron nitride, magnesia, boehmite, calcium carbonate, aluminum hydroxide and talc. Further, the thermosetting resin composition may contain a known curing agent, catalyst and the like, if necessary.

The insulating protective material 5 is preferably provided between the capacitor element 1 and the metal foil 4. In the present embodiment, as shown in FIGS. 1A and 1B, the insulating protective material 5 is provided between the capacitor element 1 and the metal foil 4, and covers the entire surface of the capacitor element 1 and a part of the metallikon electrode 2. Cover. By providing the insulating protective material 5 between the capacitor element 1 and the metal foil 4 in this way, it becomes easier to prevent moisture absorption from the surface of the capacitor element 1.

The insulating protective material 5 preferably electrically insulates the metal foil 4 and the metallikon electrode 2. As described above, in the present embodiment, the insulating protective material 5 covers the entire surface of the capacitor element 1 and the side surface of the metallikon electrode 2. Therefore, even if the metal foil 4 for covering the capacitor element 1 is provided on the insulating protective material 5, the metal foil 4 and the metallikon electrode 2 are electrically insulated, and a short circuit can be prevented.

The insulating protective material 5 preferably covers the boundary between both end faces and the side surfaces of the capacitor element 1. In the present embodiment, the heat-shrinkable tube 6 described later covers the boundary between both end faces and the side surfaces of the capacitor element 1, and the insulating protective material 5 covers the boundary between both end faces and the side surfaces of the capacitor element 1. Not covered. However, for example, when the capacitor 10 does not have the heat-shrinkable tube 6, or when the heat-shrinkable tube 6 does not cover the boundary between both end faces and the side surfaces of the capacitor element 1, the insulating protective material 5 is the capacitor element 1. It is preferable to cover the boundary between both end faces and the side surfaces of the above. As a result, it is possible to prevent moisture or gas such as steam from entering from the boundary between both end faces and the side surfaces of the capacitor element 1, and the capacitor 10 can have more excellent moisture resistance.

In FIGS. 1A and 1B, one insulating protective material 5 covers the entire surface of the capacitor element 1 and the side surfaces of the pair of metallikon electrodes 21 and 22, but is not limited to this. Using a pair of insulating protective materials 5, a part of the side surface of the metallikon electrode 21 and the surface of the capacitor element 1 on the metallikon electrode 21 side, and one of the side surface of the metallikon electrode 22 and the surface of the capacitor element 1 on the metallikon electrode 22 side. The portions may be covered with each other. Even in this case, since the metal foil 4 and the metallikon electrodes 21 and 22 are electrically insulated from each other, a short circuit can be prevented. However, from the viewpoint of simplifying the manufacturing process and improving the moisture resistance of the capacitor 10, one insulating protective material 5 forms the entire surface of the capacitor element 1 and the metallikon electrode 21 as shown in FIGS. 1A and 1B. , 22 are preferably covered with the side surface.

When the capacitor 10 has an insulating protective material 5 and the metal foil 4 and the metallikon electrode 2 are electrically insulated by the insulating protective material 5, the metal foil 4 is formed by the metallikon electrode 2 and the capacitor element 1. It is preferable to cover the boundary portion. That is, as shown in FIGS. 1A and 1B, the end portion of the metal foil 4 extends outward from the boundary portion between the metallikon electrode 2 and the capacitor element 1, and is connected to the metallikon electrode 2 via the insulating protective material 5. It is preferable to cover the boundary portion with the capacitor element 1. In this case, it becomes easy to prevent moisture or gas such as water vapor from entering from the boundary portion between the metallikon electrode 2 and the capacitor element 1, so that the moisture resistance of the capacitor 10 can be further improved.

When the capacitor 10 does not have the insulating protective material 5, the metal foil 4 is provided so as not to come into contact with the metallikon electrodes 21 and 22. Thereby, a short circuit can be prevented. In this case, for example, using a metal foil 4 having a width shorter than the distance from the boundary between the metallikon electrode 21 and the capacitor element 1 to the boundary between the metallikon electrode 22 and the capacitor element 1, only the central portion of the capacitor element 1 is used. Can be coated with the metal foil 4 so as not to come into contact with the metallikon electrodes 21 and 22. The distance between the boundary portion between the metallikon electrode 21 and the capacitor element 1 and the end portion of the metal foil 4 on the metallicon electrode 21 side is preferably 3 mm or more. Further, the distance between the boundary portion between the metallikon electrode 22 and the capacitor element 1 and the end portion of the metal foil 4 on the metallicon electrode 22 side is preferably 3 mm or more. In this case, it becomes easier to prevent contact between the metallikon electrodes 21 and 22 and the metal foil 4. It is more preferable that the distance between the boundary portion between the metallikon electrode 21 and the capacitor element 1 and the end portion of the metal foil 4 on the metallicon electrode 21 side is 5 mm or more. Further, it is more preferable that the distance between the boundary portion between the metallikon electrode 22 and the capacitor element 1 and the end portion of the metal foil 4 on the metallicon electrode 22 side is 5 mm or more.

The capacitor 10 preferably further includes a heat shrink tube 6 that covers at least a part of the metal foil 4. The heat-shrinkable tube 6 is a resin member formed in a tubular shape and has a property of shrinking when heat is applied.

It is preferable that the metal foil 4 is not exposed to the outside. That is, the heat-shrinkable tube preferably covers the entire metal foil 4. As shown in FIGS. 1A and 1B, the metal foil 4 is preferably arranged between the insulating protective material 5 and the heat shrink tube 6 so as not to be exposed. By not exposing the metal foil 4 to the outside in this way, it is possible to prevent the metal foil 4 and the metallikon electrode 2 from coming into contact with each other and causing a short circuit. Further, since the metal foil 4 is not exposed to the outside, the moisture resistance of the capacitor 10 can be particularly improved.

In the heat-shrinkable tube 6, for example, the heat-shrinkable tube 6 is cut out according to the length of the condenser 10, and the cut-out heat-shrinkable tube 6 is fitted in the condenser 10 and heated, whereby the heat-shrinkable tube 6 is contracted, whereby the condenser The heat shrink tube 6 can be brought into close contact with the 10. The material, thickness, and size of the heat-shrinkable tube 6 are not particularly limited, and any one can be used according to the size of the capacitor 10. Since the capacitor 10 has the heat-shrinkable tube 6, it is possible to prevent moisture such as water vapor and gas from entering the inside of the capacitor element 1, and the capacitor 10 can have better moisture resistance. The heat-shrinkable tube 6 is preferably mounted on the outermost layer of the capacitor 10.

The heat-shrinkable tube 6 preferably covers the boundary between both end faces and the side surfaces of the capacitor element 1. In the present embodiment, as shown in FIGS. 1A and 1B, the heat-shrinkable tube 6 covers the boundary between both end faces and the side surfaces of the capacitor element 1 and partially covers both end faces of the capacitor element 1. There is. As a result, it is possible to prevent moisture or gas such as steam from entering from the boundary between both end faces and the side surfaces of the capacitor element 1, and the capacitor 10 can have more excellent moisture resistance.

The capacitor 10 may further include a bus bar (not shown). A pair of bus bars can be adhered to the metallikon electrodes 21 and 22, respectively, and the metallikon electrodes 21 and 22 and the pair of bus bars can be electrically connected to each other. The bus bar is not particularly limited, and for example, a bus bar formed of copper, a copper alloy, or the like in a plate shape can be used. The method of bonding the bus bar to the metallikon electrode 2 is not particularly limited, and the bus bar can be bonded by, for example, solder welding, resistance welding, ultrasonic welding or the like. From the viewpoint of preventing a short circuit, when the capacitor 10 has the metal foil 4, the bus bar is provided so as not to come into contact with the metal foil 4 and to electrically insulate the bus bar and the metal foil 4.

The capacitor 10 may include a resin encapsulant (not shown) that covers the metallikon electrodes 21 and 22. By coating the metallikon electrode 2 with a resin encapsulant, it becomes easier to prevent moisture absorption by the external electrode 2.

The material of the resin encapsulant is not particularly limited, and any resin material that is less likely to allow moisture or gas such as water vapor to permeate than the metallikon electrode 2 may be used. For example, a thermosetting resin such as an epoxy resin can be used as the material of the resin encapsulant. In this case, the resin encapsulant can be formed by adhering the bus bar to the metallikon electrode 2 and then applying and curing such a resin material so as to cover the metallikon electrode 2. When a thermosetting resin is used as the material of the resin encapsulant, the curing temperature of the thermosetting resin is preferably 120 ° C. or lower. In this case, the influence of heat on the capacitor element 1 when curing the prepreg can be reduced. A resin non-sealing material may be formed by using a resin composition in which an inorganic filler, a known curing agent, a catalyst, or the like is added to the resin.

The capacitor 10 may include a water-repellent layer (not shown) that covers a pair of metallikon electrodes 21 and 22. By coating the metallikon electrode 2 with a water-repellent layer, it becomes easy to prevent moisture absorption by the metallikon electrode 2.

The material of the water-repellent layer is not particularly limited, and the water-repellent layer may be formed by using a material that is less likely to allow moisture or gas such as water vapor to permeate than the metallikon electrode 2. For example, a water-repellent layer can be formed by using a fluorine-based or silicon-based water repellent. In this case, after the bus bar is adhered to the metallikon electrode 2, a water repellent layer can be formed by applying a water repellent agent so as to cover the metallikon electrode 2 and drying the bus bar.

3. 3. Aspects As will be clear from the above embodiments and modifications, the present disclosure includes the following aspects. In the following, reference numerals are given in parentheses only to clearly indicate the correspondence with the embodiments.

The capacitor (10) according to the first aspect includes a capacitor element (1) and a pair of metallikon electrodes (2) provided on both end faces of the capacitor element (1), and the pair of metallicon electrodes (1). 2) covers the boundary between both end faces and the side surfaces of the capacitor element (1).

According to the first aspect, it is possible to obtain a capacitor (10) having excellent moisture resistance while realizing weight reduction.

In the capacitor (10) according to the second aspect, in the first aspect, the capacitor element (1) is an exterior material (12) that covers at least a part of a main body (11) and a side surface of the main body (11). The exterior material (12) is formed of a non-stretched film.

According to the second aspect, the adhesion between the metallikon electrode (2) and the capacitor element (1) can be improved.

The capacitor (10) according to the third aspect further includes a metal foil (4) that covers at least a part of the capacitor element (1) in the first or second aspect.

According to the third aspect, it becomes easier to prevent moisture absorption from the surface of the capacitor element (1).

The capacitor (10) according to the fourth aspect further includes an insulating protective material (5) provided between the capacitor element (1) and the metal foil (4) in the third aspect.

According to the fourth aspect, it becomes easier to prevent moisture absorption from the surface of the capacitor element (1), and it becomes easier to prevent a short circuit.

In the capacitor (10) according to the fifth aspect, in the fourth aspect, the insulating protective material (5) is at least one selected from the group consisting of an insulating film, a gas barrier film, and a cured product of a prepreg. Including.

According to the fifth aspect, it becomes easier to prevent moisture absorption from the surface of the capacitor element (1).

The capacitor (10) according to the sixth aspect further includes a heat shrink tube (6) that covers at least a part of the metal foil (4) in any one of the third to fifth aspects.

According to the sixth aspect, the moisture resistance of the capacitor (10) can be further improved.

The method for manufacturing a capacitor (10) according to a seventh aspect is a pair of metallikon electrodes (2) that cover both end faces of the capacitor element (1) with a boundary portion between both end faces and side surfaces of the capacitor element (1). ) Is included.

According to the seventh aspect, it is possible to obtain a capacitor (10) having excellent moisture resistance while realizing weight reduction.

In the method for manufacturing a capacitor (10) according to the eighth aspect, in the seventh aspect, the capacitor element (1) includes a main body (11) and an exterior material (12), and at least a side surface of the main body (11) is provided. The step of covering a part with the exterior material (12) is further included.

According to the eighth aspect, the adhesion between the metallikon electrode (2) and the capacitor element (1) can be improved.

In the method for manufacturing the capacitor (10) according to the ninth aspect, in the eighth aspect, the exterior material (12) is formed of a non-stretched film.

According to the ninth aspect, the adhesion between the metallikon electrode (2) and the capacitor element (1) can be improved.

The method for manufacturing the capacitor (10) according to the tenth aspect further includes a step of roughening the exterior material (12) in the eighth aspect.

According to the tenth aspect, the adhesion between the metallikon electrode (2) and the capacitor element (1) can be improved.

10 Capacitor 1 Capacitor element 11 Main body 12 Exterior material 2 Metallicon electrode 4 Metal foil 5 Insulating protective material 6 Heat shrink tube

Claims (10)

Capacitor element and
A pair of metallikon electrodes provided on both end faces of the capacitor element are provided.
The pair of metallikon electrodes are capacitors that cover the boundary between both end faces and side surfaces of the capacitor element. The capacitor element includes a main body and an exterior material that covers at least a part of the side surface of the main body.
The exterior material is formed of a non-stretched film.
The capacitor according to claim 1. Further comprising a metal foil covering at least a part of the capacitor element.
The capacitor according to claim 1 or 2. Further provided with an insulating protective material provided between the capacitor element and the metal foil.
The capacitor according to claim 3. The insulating protective material comprises at least one selected from the group consisting of an insulating film, a gas barrier film, and a cured product of a prepreg.
The capacitor according to claim 4. Further comprising a heat shrink tube covering at least a part of the metal foil.
The capacitor according to any one of claims 3 to 5. A step of forming a pair of metallicon electrodes covering the boundary between both end faces and the side surfaces of the capacitor element is included on both end faces of the capacitor element.
How to make a capacitor. The capacitor element includes a main body and an exterior material, and has
Further including a step of covering at least a part of the side surface of the main body with the exterior material.
The method for manufacturing a capacitor according to claim 7. The exterior material is formed of a non-stretched film.
The method for manufacturing a capacitor according to claim 8. Further including a step of roughening the exterior material,
The method for manufacturing a capacitor according to claim 8.

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