JP2021052114A - Electrolytic capacitor - Google Patents

Abstract

To prevent short-circuiting between an exterior member and lead terminals.SOLUTION: An electrolytic capacitor comprises: a capacitor element having an anode part and a cathode part; lead terminals which are connected to the anode part and the cathode part, respectively; an exterior member having a conductive lateral wall which at least partially surrounds the capacitor element and a bottom face from which at least one of the lead terminals is partially exposed; and a frame-like insulating member which insulates the lateral wall from the one of the lead terminals exposed from the bottom face. The insulating member has: a base part which supports a first end on the bottom face side of the lateral wall; and a rib which is erected from the base part along the lateral wall.SELECTED DRAWING: Figure 1

Description

The present invention relates to an electrolytic capacitor, and more particularly to an electrolytic capacitor including a conductive exterior member accommodating a capacitor element.

Electrolytic capacitors are installed in various electronic devices because they have a small equivalent series resistance (ESR) and excellent frequency characteristics. An electrolytic capacitor usually includes a capacitor element including an electrode portion, a lead terminal electrically connected to the electrode portion, and an exterior member accommodating the capacitor element.

Patent Document 1 uses a metal case as an exterior member. The metal case is provided with a notch, and the lead terminal is inserted through this notch.

JP-A-2007-103575

In the configuration of Patent Document 1, the metal case and the lead terminal may be short-circuited.

One aspect of the present invention is a capacitor element having an anode portion and a cathode portion, a lead terminal connected to the anode portion and the cathode portion, respectively, and a side wall that surrounds at least a part of the capacitor element and has conductivity. The insulating member includes an exterior member having a bottom surface on which at least a part of the lead terminal is exposed, and a frame-shaped insulating member that insulates the side wall and the lead terminal exposed from the bottom surface. The present invention relates to an electrolytic capacitor, comprising a base portion that supports the first end portion of the side wall surface on the bottom surface side, and ribs that rise from the base portion along the side wall.

According to the present invention, a short circuit between the conductive exterior member and the lead terminal is suppressed.

It is sectional drawing which shows typically the electrolytic capacitor which concerns on one Embodiment of this invention. It is a perspective view which shows typically the insulating member which concerns on 1st Embodiment of this invention. It is a top view which shows typically the insulating member which concerns on 1st Embodiment of this invention. It is a perspective view which shows typically the insulating member which concerns on 2nd Embodiment of this invention. It is a top view which shows typically the insulating member which concerns on 2nd Embodiment of this invention. It is a perspective view which shows typically the insulating member which concerns on 3rd Embodiment of this invention. It is a top view which shows typically the insulating member which concerns on 3rd Embodiment of this invention. It is a perspective view which shows typically the insulating member which concerns on 4th Embodiment of this invention. It is a back view which shows typically the insulating member which concerns on 4th Embodiment of this invention. It is a perspective view which shows typically the insulating member which concerns on 5th Embodiment of this invention. It is a back view which shows typically the insulating member which concerns on 5th Embodiment of this invention. It is sectional drawing which shows typically the capacitor element which concerns on embodiment of this invention. It is sectional drawing which shows typically the laminated capacitor element which concerns on embodiment of this invention.

The capacitor element is housed in an exterior member. The exterior member comprises a side wall that surrounds at least a portion of the capacitor element. The lead terminal connected to the capacitor element extends across the side wall to the outside of the exterior member and is exposed from one side of the electrolytic capacitor. The electrolytic capacitor is mounted with the exposed surface of the lead terminal facing the electronic component.

The side walls of the exterior member are conductive. Therefore, in the present embodiment, the electrolytic capacitor is provided with a frame-shaped insulating member that insulates the exterior member and the exposed lead terminal (hereinafter, referred to as an exposed lead terminal). As a result, a short circuit between the exterior member and the exposed lead terminal is suppressed.

That is, the electrolytic capacitor according to the present embodiment has a capacitor element having an anode portion and a cathode portion, a lead terminal connected to the anode portion and the cathode portion, respectively, and a side wall that surrounds at least a part of the capacitor element and has conductivity. , And an exterior member having a bottom surface on which at least a part of one of the lead terminals is exposed, and a frame-shaped insulating member that insulates the side wall and the lead terminal exposed from the bottom surface. Hereinafter, the surface on which the lead terminals of the exterior member are exposed is simply referred to as a bottom surface.

The insulating member has a frame shape and includes a base portion that supports the first end portion on the bottom surface side of the side wall, and a rib that rises from the base portion. The base is a frame that can be along the first end of the side wall. The rib rises from the base along the side wall toward the side opposite to the bottom surface. The ribs may be arranged inside the side wall or outside.

The base prevents contact between the first end of the side wall and the exposed lead terminal. Therefore, the side wall and the exposed lead terminal are insulated. Further, since the base has a frame shape, the insulating member can be easily positioned and fixed. The ribs suppress the misalignment of the insulating member. Therefore, the certainty of insulation between the side wall and the exposed lead terminal is increased. In addition, the ribs make it easier to position the insulating member.

The exposed lead terminal may be an anode lead terminal connected to the anode portion, a cathode lead terminal connected to the cathode portion, or both an anode lead terminal and a cathode lead terminal.

The capacitor element may be sealed with a non-conductive sealing resin. That is, the exterior member may include a side wall and a sealing resin. The sealing resin suppresses the permeation of oxygen and moisture into the electrolytic capacitor, suppresses the deterioration of the capacitor element, and improves the heat insulating performance. In this case, the bottom surface of the exterior member is formed of a sealing resin. Further, the exterior member may include a ceiling portion that closes one opening of the side wall. Hereinafter, the side wall and the ceiling may be collectively referred to as an exterior case.

FIG. 1 is a cross-sectional view schematically showing an electrolytic capacitor according to the present embodiment. However, the present invention is not limited to this.
The electrolytic capacitor 100 includes a capacitor element 110, an anode lead terminal 120A, a cathode lead terminal 120B, an exterior member 130, and an insulating member 140.

The exterior member 130 includes a side wall 131, a ceiling portion 132 integrally molded with the side wall 131, and a sealing resin 133. The ceiling portion 132 is arranged on a surface opposite to the bottom surface 130X. The capacitor element 110 is sealed with the sealing resin 133 and is housed in the side wall 131 and the ceiling portion 132. The bottom surface 130X is formed of the sealing resin 133.

The capacitor element 110 has an anode portion 110a and a cathode portion 110b. An anode lead terminal 120A is connected to the anode portion 110a. A cathode lead terminal 120B is connected to the cathode portion 110b. A part of both the anode lead terminal 120A and the cathode lead terminal 120B is exposed from the exterior member 130.

A frame-shaped insulating member 140 is interposed between the first end portion 131a of the side wall 131 and the anode lead terminal 120A and the cathode lead terminal 120B. The insulating member 140 has a base portion 141 that is interposed between the first end portion 131a and the anode lead terminal 120A and between the first end portion 131a and the cathode lead terminal 120B to support the first end portion 131a. It is provided with a rib 142 rising from the base 141. The rib 142 is arranged inside the side wall 131.

[Insulation member]
The insulating member has a frame shape and insulates the side wall and the lead terminal.
The insulating member includes a base portion that supports the first end portion on the bottom surface side of the side wall, and a rib that rises from the base portion. The base and the rib may be integrally molded or may be separate bodies.

The material of the insulating member is not particularly limited, and resins such as thermosetting resin, thermoplastic resin, and ultraviolet curable resin; ceramics such as aluminum oxide, zirconium dioxide, aluminum nitride, and silicon nitride; styrene butadiene rubber, isoprene rubber, and butadiene. Examples include rubbers such as rubber, ethylene propylene rubber, urethane rubber, silicone rubber, and fluororubber; glass; thermosetting paper, and composite materials thereof.

It is preferable that the insulating member is easy to mold, has high heat resistance, and has a coefficient of linear expansion equivalent to that of the side wall. The heat resistant temperature of the insulating member is preferably equal to or higher than the general reflow temperature (for example, 260 degrees). The coefficient of linear expansion of the insulating member is preferably 30 ppm / ° C. or less. Examples of the material satisfying these conditions include crystalline thermoplastic resins. Examples of the crystalline thermoplastic resin include polyphenylene sulfide (PPS), liquid crystal polymer (LCP), polyetheretherketone (PEEK) and the like.

(base)
The base is a frame that can be along the first end of the side wall. When viewed from the bottom surface side, the first end portion overlaps the base portion, and a part of the base portion protrudes from the first end portion. Other than this point, the shape of the base is not particularly limited. When the side wall is a frame having a plurality of corners, the base is also a frame having a plurality of corners.

From the viewpoint of space saving, it is preferable that the base portion does not excessively protrude to the outside of the side wall when viewed from the bottom surface side. When the ribs are arranged inside the side wall, the amount of protrusion L1 of the base portion from the side wall to the outside is preferably 0.1 mm or less, and more preferably 0.05 mm or less. When the ribs are arranged on the outside of the side wall, the amount of protrusion L1 of the base from the side wall to the outside is preferably not more than the sum of the rib thickness and 0.1 mm, and the rib thickness and 0.05 mm. It is more preferably less than or equal to the sum.

From the viewpoint of design freedom, it is preferable that the base does not excessively protrude inside the side wall when viewed from the bottom surface side. When the rib is arranged inside the side wall, the amount of protrusion L2 of the base from the side wall to the inside is preferably not more than the sum of the rib thickness and 0.1 mm, and the rib thickness and 0.05 mm. It is more preferably less than or equal to the sum. When the ribs are arranged on the outside of the side wall, the amount of protrusion L2 of the base portion from the side wall to the inside is preferably 0.1 mm or less, and more preferably 0.05 mm or less.

The amount of protrusion L1 of the base portion from the side wall to the outside is obtained by arbitrarily measuring the distance between the outermost portion of the first end portion and the outermost portion of the base portion at three points when viewed from the bottom surface side. , Calculated as the average value. The amount of protrusion L2 of the base from the side wall to the inside measures the distance between the innermost part of the first end and the innermost part of the base at three arbitrary points when viewed from the bottom surface side. , Calculated as the average value. Here, the outside or the inside means the outside or the inside with respect to the electrolytic capacitor.

The thickness of the base is not particularly limited. From the viewpoint of insulation and low profile, the thickness of the base may be, for example, 0.05 mm or more and 1 mm or less, and 0.1 mm or more and 0.5 mm or less. The thickness of the base is calculated as an average value by arbitrarily measuring the distance between the main surface (first main surface) on the bottom surface side of the base and the main surface (second main surface) on the opposite side at three points. Will be done.

(rib)
The ribs rise from the base along the side walls towards the ceiling. The presence of the ribs suppresses the displacement of the insulating member and makes it easier to position the insulating member.

The ribs may be located inside the side wall. In this case, since the outer shape of the electrolytic capacitor is almost the same, the degree of freedom in design is improved. Further, when the exterior member includes a sealing resin, the insulating member is easily fixed. In addition, when the raw material of the sealing resin is filled in the outer case, it is easy to prevent the raw material from flowing out to the outside of the outer case.

The ribs may be located on the outside of the side wall. In this case, since the internal volume of the outer case is almost the same, a large capacitor element can be accommodated.

From the viewpoint of space saving and fixability, it is preferable that the rib is arranged so that a part of the rib is in contact with the side wall. More preferably, the ribs are arranged so as to fit into the side wall. In these cases, an adhesive may be interposed between the rib and the side wall. As a result, the fixing property of the insulating member is further improved. The adhesive is preferably non-conductive and is preferably a thermosetting resin, which will be described later.

The ribs need only rise from at least a part of the base. From the viewpoint of fixing and positioning, the ribs preferably rise from the entire circumference of the frame-shaped base. In other words, the ribs preferably rise from the base so as to surround the opening formed by the frame-shaped base. When the ribs rise from a part of the base, it is preferable that a plurality of ribs are intermittently arranged along the circumferential direction of the base.

If the side wall is a frame with corners, the preferred rib is a frame with corners that fits into the side wall. When the ribs are arranged inside the side wall, it is preferable that at least one of the plurality of corners is formed with an inwardly recessed step in the frame-shaped rib having a corner that fits the side wall. Due to the step, the inner diameter of the frame-shaped rib is partially reduced. As a result, the thickness at the corner of the side wall can be increased, and the strength of the side wall can be increased.

The shape of the step portion is not particularly limited. The step portion is formed in a step shape of one or more steps, for example. The amount of dent inward (step G) of the step portion is not particularly limited, and may be appropriately set in consideration of the thickness at the corner of the side wall. The step G is, for example, 0.02 mm or more and 0.5 mm or less, and may be 0.05 mm or more and 0.2 mm or less. The step G is calculated as an average value obtained by arbitrarily measuring the amount of dents in the step portion at three points when the insulating member is viewed from the second main surface of the base portion.

In the frame-shaped rib having an angle to be fitted to the side wall, a notch may be formed at at least one of the plurality of corners. Thereby, similarly to the above, the thickness at the corner of the side wall can be increased, and the strength of the side wall can be increased. In addition, the notch allows the rib to be tilted inward or outward. Therefore, for example, when assembling the insulating member, the rib is less likely to be loaded, and damage to the insulating member, deformation of the outer case, and the like are easily suppressed. Both the step and the notch may be formed at at least one of the plurality of corners. Steps and / or notches may be formed at all of the corners.

The notch is formed, for example, to divide the frame-shaped rib. The shape of the notch is not particularly limited, and may be rectangular or V-shaped. The width W of the notch is not particularly limited, and may be appropriately set in consideration of the thickness at the corner of the side wall. The width W of the notch may be, for example, 0.05 mm or more and 2 mm or less, and may be 0.05 mm or more and 1.5 mm or less. The width W of the notch is calculated as an average value by arbitrarily measuring the distances of the gaps on the inner surface side of the ribs at three points when the insulating member is viewed from the direction horizontal to the second main surface of the base.

The frame-shaped side wall having corners is produced, for example, by bending or drawing a metal plate. At this time, the corners of the side wall tend to be thick. The thickened side wall corners are accommodated in the above-mentioned steps and / or notches provided in the ribs. Therefore, even if the insulating member is arranged, the capacitor element having the same size as the conventional one can be accommodated in the outer case.

The thickness of the rib is not particularly limited. From the viewpoint of fixability and space saving, the thickness of the rib may be, for example, 0.05 mm or more and 1 mm or less, and 0.1 mm or more and 0.5 mm or less. The thickness of the rib is calculated as an average value by arbitrarily measuring the distance between the inner surface and the outer surface of the rib at three points.

The height of the rib is not particularly limited, and is appropriately set according to the first end portion. From the viewpoint of fixability and space saving, the height of the rib may be, for example, 0.1 mm or more and 2 mm or less, and may be 0.2 mm or more and 1.5 mm or less. The height of the rib is calculated as an average value by arbitrarily measuring the distance from the second main surface of the base to the end surface of the rib on the ceiling side at three points.

(Convex part)
It is preferable that at least two convex portions are arranged on the bottom surface side surface of the base portion. That is, it is preferable that the base portion is provided with a convex portion that protrudes in the direction opposite to the rib. The exposed lead terminals are arranged between these protrusions. When an electrolytic capacitor is mounted on an electronic component, a space is formed between the electronic component and the base by the convex portion. When the lead terminal is passed between the convex portions, at least a part of the thickness of the exposed lead terminal is absorbed in the above space.

Normally, when an electrolytic capacitor is mounted on an electronic component, the exposed lead terminal comes into contact with the electronic component, while a portion other than the exposed lead terminal of the electrolytic capacitor cannot come into contact with the electronic component. That is, a part of the electrolytic capacitor is lifted from the electronic component by the thickness of the exposed lead terminal, and is easily shaken. If soldering is performed in this state, the electrolytic capacitor may be tilted or the electrolytic capacitor may be misaligned.

According to this embodiment, the amount of lifting of the electrolytic capacitor from the electronic component is small, or a plurality of convex portions come into contact with the electronic component, so that the posture of the electrolytic capacitor is easily stabilized. Therefore, it is possible to prevent the electrolytic capacitor from tilting or shifting due to soldering.

The height of the convex portion is preferably equal to or less than the thickness of the exposed lead terminal. As a result, at least a part or all of the thickness of the exposed lead terminal is absorbed in the space formed between the electronic component and the base. Therefore, the posture of the electrolytic capacitor is stable as compared with the case where there is no convex portion. From the viewpoint of low profile and connection reliability, the height H of the convex portion is preferably 0.5 times or more and 1.1 times or less, and 0.8 times or more and 1.0 times or more the thickness of the exposed lead terminal. It is more preferable that it is as follows.

The arrangement of the convex portions is not particularly limited. The convex portion is arranged in a region (hereinafter, referred to as a non-opposing region) other than the region crossed by the exposed lead terminal in the first main surface of the base portion. The convex portion may be arranged so as to cover the entire non-opposing region, or may be partially arranged in the non-opposing region. Among them, it is preferable that the plurality of convex portions are partially arranged in the non-opposing region. When the raw material of the sealing resin is filled in the outer case, the raw material tends to get wet along the convex portion. By partially arranging the convex portion, the wetness of the raw material is suppressed, and the raw material is easily suppressed from flowing out to the outside of the outer case. When the base portion is a frame body having a plurality of corners, the convex portions are preferably arranged so as to avoid the corners of the base portion. This is because the raw material of the sealing resin tends to get wet at the corners of the base.

When the convex portions are partially arranged in the non-opposing region, it is preferable that three or more convex portions are arranged. As a result, one plane passing through the convex portion is determined, so that the shaking of the electrolytic capacitor is easily suppressed, and the posture is further stabilized.

Hereinafter, the insulating member according to the present embodiment will be specifically described with reference to the drawings. However, this embodiment is not limited to this.

[First Embodiment]
FIG. 2A is a perspective view schematically showing an insulating member according to the present embodiment. FIG. 2B is a top view schematically showing an insulating member according to the present embodiment. FIG. 2B shows the insulating member from the second main surface side of the base.

In the present embodiment, the insulating member 140A has a frame-shaped base 141 having four corners, and a frame-shaped rib 142 rising from the entire circumference of the base 141 and having four corners. The rib 142 projects toward the second main surface 141Y side of the base portion 141. The rib 142 is arranged inside the side wall and fits into the side wall. Step portions 142a for reducing the inner diameter of the rib 142 are formed at each of the four corners of the rib 142. The step portion 142a is one step. The recessed amount (step G) of the step portion 142a is about 0.07 mm.

[Second Embodiment]
FIG. 3A is a perspective view schematically showing an insulating member according to the present embodiment. FIG. 3B is a top view schematically showing an insulating member according to the present embodiment. FIG. 3B shows the insulating member from the second main surface side of the base.

The insulating member 140B according to the present embodiment has the same configuration as that of the first embodiment except that notches 142b are formed at four corners of the rib 142 together with a step portion 142a for reducing the inner diameter of the rib 142. Have. The notch 142b divides the rib 142 into four parts. The width W of the notch 142b is about 0.1 mm.

[Third Embodiment]
FIG. 4A is a perspective view schematically showing an insulating member according to the present embodiment. FIG. 4B is a top view schematically showing an insulating member according to the present embodiment. FIG. 4B shows the insulating member from the second main surface side of the base.

In the present embodiment, the insulating member 140C has a frame-shaped base 141 having four corners, and a frame-shaped rib 142 rising from the entire circumference of the base 141 and having four corners. The rib 142 is arranged outside the side wall and fits into the side wall.

[Fourth Embodiment]
FIG. 5A is a perspective view schematically showing an insulating member according to the present embodiment. FIG. 5B is a back view schematically showing the insulating member according to the present embodiment. FIG. 5B shows the insulating member from the first main surface side of the base. In FIG. 5B, non-opposing regions are hatched for convenience.

The insulating member 140D according to the present embodiment has the same configuration as that of the first embodiment except that a plurality of convex portions 143 are partially arranged in the non-opposing region 141a on the first main surface 141X of the base portion 141. Have. The height H of the convex portion 143 is about 0.09 mm. The plurality of convex portions 143 are arranged in the vicinity of the corners of the base portion 141, avoiding the corners. A total of eight convex portions 143 are arranged.

[Fifth Embodiment]
FIG. 6A is a perspective view schematically showing an insulating member according to the present embodiment. FIG. 6B is a back view schematically showing the insulating member according to the present embodiment. FIG. 6B shows the insulating member from the first main surface side of the base. In FIG. 5B, non-opposing regions are hatched for convenience.

The insulating member 140E according to the present embodiment has the same configuration as that of the fourth embodiment except that the two convex portions 143 are arranged so as to cover the entire two non-opposing regions 141a.

[Exterior member]
The exterior member includes a side wall that surrounds at least a part of the capacitor element and has conductivity, and a bottom surface that exposes a part of at least one lead terminal. The appearance of the exterior member is generally a rectangular parallelepiped. The exterior member may be provided with a ceiling portion on the side opposite to the bottom surface. The side wall and the ceiling may be integrally molded or may be separate bodies. The integral side wall and ceiling (ie, exterior case) are molded, for example, by drawing a metal plate.

(Wall wall)
The side wall is frame-shaped and extends in the direction of intersecting the bottom surface. The side wall has, for example, a plurality of corners. One opening on the side wall may be closed by a ceiling.

The side walls are conductive. The material of the side wall is not particularly limited as long as it has conductivity, and examples thereof include a metal material. Examples of the metal material include aluminum, titanium, tantalum, iron, copper, zinc, nickel, molybdenum, tungsten, and composite materials thereof. Since the side wall of the exterior member contains a metal material, the permeation of oxygen and water into the electrolytic capacitor is suppressed, and the deterioration of the capacitor element is suppressed.

The first end of the side wall is a region that combines an inner region that is a part of the inner surface of the side wall and is formed along the side on the bottom surface side and the end surface of the side wall that connects the inner region and the outer surface of the side wall. Is. The inner region occupies, for example, 30% or less of the area of the inner surface of the side wall, and may occupy 20%.

(Encapsulating resin)
The exterior member may include a sealing resin. The sealing resin is filled in, for example, the gap between the capacitor element and the side wall and the gap between the capacitor element and the ceiling portion, and also covers the bottom surface side of the capacitor element. In this case, the bottom surface of the electrolytic capacitor is formed of a sealing resin.

A protective layer having low permeability to at least one of oxygen and moisture may be formed on the bottom surface made of the sealing resin. As a result, deterioration of the capacitor element is more likely to be suppressed. The inner surface of the side wall and the surface of the lead terminal may be roughened. As a result, the adhesion between the sealing resin and the inner surface of the side wall and the lead terminal is improved.

The sealing resin is non-conductive and includes, for example, a cured product of a thermosetting resin and engineering plastics. Examples of the thermosetting resin include epoxy resin, phenol resin, silicone resin, melamine resin, urea resin, alkyd resin, polyurethane, and unsaturated polyester. Engineering plastics include general purpose engineering plastics and super engineering plastics. Examples of engineering plastics include polyimide and polyamide-imide.

[Lead terminal]
The anode lead terminal is electrically connected to the anode portion of the capacitor element. The material of the anode lead terminal is not particularly limited as long as it is electrochemically and chemically stable and has conductivity, and may be metal or non-metal. The shape is also not particularly limited. The thickness of the anode lead terminal (distance between the main surfaces of the anode terminal) is preferably 25 μm or more and 200 μm or less, and more preferably 25 μm or more and 100 μm or less from the viewpoint of reducing the height.

The anode lead terminal may be electrically connected to the anode portion via a conductive adhesive or solder, or may be joined to the anode portion by resistance welding or laser welding. The conductive adhesive is, for example, a mixture of a thermosetting resin and carbon particles or metal particles.

The cathode lead terminal is electrically connected to the cathode portion of the capacitor element. The material of the cathode lead terminal is also not particularly limited as long as it is electrochemically and chemically stable and has conductivity, and may be metal or non-metal. The shape is also not particularly limited. From the viewpoint of reducing the height, the thickness of the cathode lead terminal is preferably 25 μm or more and 200 μm or less, and more preferably 25 μm or more and 100 μm or less. The cathode lead terminal is electrically connected to the cathode portion via, for example, a conductive adhesive.

[Capacitor element]
The capacitor element has an anode portion and a cathode portion.
The anode portion is composed of an anode body.
The cathode portion includes an anode, a dielectric layer formed on at least a part of the surface of the anode body, and a cathode layer formed on at least a part of the surface of the dielectric layer. The cathode layer has a solid electrolyte layer formed on at least a part of the dielectric layer and a cathode extraction layer formed on at least a part of the solid electrolyte layer. Such a capacitor element is, for example, a sheet or a flat plate.

(Anode)
The anode body includes a foil (metal foil) containing a valve acting metal as a conductive material or a porous sintered body containing a valve acting metal. Anode wires are planted from the porous sintered body. The anode wire is used for connection with the anode lead terminal. Examples of the valve acting metal include titanium, tantalum, aluminum and niobium. The anode body may contain one kind or two or more kinds of the above-mentioned valve action metals. The anode body may contain the valve acting metal in the form of an alloy containing the valve acting metal, a compound containing the valve acting metal, or the like. The thickness of the anode body, which is a metal foil, is not particularly limited, and is, for example, 15 μm or more and 300 μm or less. The thickness of the anode body, which is a porous sintered body, is not particularly limited, and is, for example, 15 μm or more and 5 mm or less.

(Dielectric layer)
The dielectric layer is formed on at least a portion of the surface of the anode. The dielectric layer is formed by, for example, anodizing the surface of the anode body by chemical conversion treatment or the like. Therefore, the dielectric layer may contain oxides of the valvening metal. For example, when aluminum is used as the valve acting metal, the dielectric layer may contain _{Al 2} O _3. The dielectric layer is not limited to this, and may be any one that functions as a dielectric.

(Cathode layer)
The cathode layer has, for example, a solid electrolyte layer and a cathode extraction layer.

The solid electrolyte layer may be formed so as to cover at least a part of the dielectric layer, and may be formed so as to cover the entire surface of the dielectric layer.
For the solid electrolyte layer, for example, a manganese compound or a conductive polymer can be used. As the conductive polymer, polypyrrole, polyaniline, polythiophene, polyacetylene, derivatives thereof and the like can be used. The solid electrolyte layer containing the conductive polymer can be formed, for example, by chemically polymerizing and / or electrolytically polymerizing the raw material monomer on the dielectric layer. Alternatively, it can be formed by applying a solution in which the conductive polymer is dissolved or a dispersion liquid in which the conductive polymer is dispersed to the dielectric layer.

The cathode extraction layer may be formed so as to cover at least a part of the solid electrolyte layer, and may be formed so as to cover the entire surface of the solid electrolyte layer.
The cathode extraction layer has, for example, a carbon layer and a metal (for example, silver) paste layer formed on the surface of the carbon layer. The carbon layer is composed of a composition containing a conductive carbon material such as graphite. The metal paste layer is composed of, for example, a composition containing silver particles and a resin. The structure of the cathode extraction layer is not limited to this, and may be any structure having a current collecting function.

FIG. 7 is a cross-sectional view schematically showing the capacitor element according to the present embodiment. The capacitor element 110 has a sheet shape. The anode portion 110a is composed of the anode body 11. The cathode portion 110b includes an anode body 11, a dielectric layer 12, and a cathode layer 13. The cathode layer 13 has a solid electrolyte layer 13a and a cathode extraction layer 13b.

The electrolytic capacitor may include a plurality of capacitor elements. A plurality of capacitor elements are laminated. The number of laminated capacitor elements is not particularly limited, and is, for example, 2 or more and 20 or less.

The anode portions of the laminated capacitor elements are joined by welding and / or caulking, etc., and are electrically connected to each other. An anode lead terminal is bonded to the anode portion of at least one capacitor element. The plurality of anode portions are crimped by, for example, bent anode lead terminals. The anode portion and the anode lead terminal may be further laser welded. As a result, the connection reliability between the plurality of anode portions and the connection reliability between the anode portions and the anode lead terminals are improved.

The cathode portions of the laminated capacitor elements are also electrically connected to each other. A cathode lead terminal is bonded to the cathode layer of at least one capacitor element. The cathode lead terminals are bonded to the cathode layer via, for example, a conductive adhesive.

FIG. 8 is a cross-sectional view schematically showing the laminated capacitor elements according to the present embodiment. In FIG. 8, seven capacitor elements are laminated, but the number thereof is not particularly limited.

The anode lead terminal 120A is bent, and the anode portions 110a of a plurality of laminated capacitor elements 110A to 110G are sandwiched in the thickness direction. The cathode lead terminal 120B is also bent, and the cathode portions 110b of a plurality of laminated capacitor elements 110A to 110G are sandwiched in the width direction.

The present invention can be used for an electrolytic capacitor including a conductive exterior member.

100: Electrolytic capacitors 110, 110A to 110G: Capacitor elements 110a: Anode part 110b: Cathode part 11: Anode body 12: Dielectric layer 13: Cathode layer 13a: Solid electrolyte layer 13b: Cathode extraction layer 120A: Anode lead terminal 120B: Cathode lead terminal 130: Exterior member 130X: Bottom surface 131: Side wall 131a: First end 132: Ceiling 133: Encapsulating resin 140, 140A to 140E: Insulation member 141: Base 141X: First main surface 141Y: Second main Surface 141a: Non-opposing region 142: Rib 142a: Step portion 142b: Notch 143: Convex portion

Claims (9)

A capacitor element having an anode part and a cathode part,
Lead terminals connected to the anode portion and the cathode portion, respectively,
An exterior member having a side wall that surrounds at least a part of the capacitor element and has conductivity, and a bottom surface that exposes at least one part of the lead terminal.
A frame-shaped insulating member that insulates the side wall and the lead terminal exposed from the bottom surface is provided.
The insulating member is an electrolytic capacitor including a base portion that supports the first end portion of the side wall surface on the bottom surface side, and ribs that rise from the base portion along the side wall. The electrolytic capacitor according to claim 1, wherein the rib rises from the entire circumference of the base. The electrolytic capacitor according to claim 1 or 2, wherein the rib is arranged inside the side wall. The rib rises from the entire circumference of the base and has a plurality of corners.
The electrolytic capacitor according to claim 3, wherein a step portion recessed inward is formed at at least one of the corners. The rib rises from the entire circumference of the base and has a plurality of corners.
The electrolytic capacitor according to claim 3 or 4, wherein a notch is formed in at least one of the corners. The electrolytic capacitor according to claim 1 or 2, wherein the rib is arranged outside the side wall. The electrolytic capacitor according to any one of claims 1 to 6, wherein an adhesive is interposed between the rib and the side wall. At least two convex portions are arranged on the bottom surface side surface of the base portion.
The electrolytic capacitor according to any one of claims 1 to 7, wherein the lead terminal exposed from the bottom surface is arranged between the convex portions. The electrolytic capacitor according to any one of claims 1 to 8, wherein the exterior member includes a sealing resin filled in a gap between the capacitor element and the side wall.

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