阅读说明：本技术 电解电容器 (Electrolytic capacitor ) 是由 植松秀典 于 2020-05-26 设计创作，主要内容包括：电解电容器具备：电容器元件、覆盖电容器元件的外装体、与电容器元件的阳极体电连接的阳极端子、与电容器元件的阴极部电连接的阴极端子。阳极端子以及阴极端子分别具备：与电容器元件接触的连接部；与连接部连接设置并从外装体的内部导出到外表面的导出部；和与导出部连接设置并且沿着外装体的外表面配置、并具有露出面的外部端子部。在阳极端子以及阴极端子的至少一个的导出部的被外装体覆盖的覆盖部分的至少一部分,与外装体的外表面的导出部被导出的表面区域平行地形成的截面具有倒角形状的角部。(An electrolytic capacitor is provided with: the capacitor element, an outer package covering the capacitor element, an anode terminal electrically connected to an anode body of the capacitor element, and a cathode terminal electrically connected to a cathode portion of the capacitor element. The anode terminal and the cathode terminal are respectively provided with: a connection portion in contact with the capacitor element; a lead-out part connected with the connecting part and led out from the inside of the outer casing to the outer surface; and an external terminal portion connected to the lead-out portion, disposed along an outer surface of the exterior body, and having an exposed surface. At least a part of a covering portion covered with the package of the lead-out portion of at least one of the anode terminal and the cathode terminal has a corner portion having a chamfered shape in cross section formed in parallel with a surface region of the outer surface of the package from which the lead-out portion is led out.)

1. An electrolytic capacitor is provided with:

a capacitor element including an anode body, a dielectric layer disposed on a surface of the anode body, and a cathode portion disposed on a surface of the dielectric layer; an outer package covering the capacitor element; an anode terminal electrically connected to the anode body; and a cathode terminal electrically connected to the cathode portion,

the anode terminal and the cathode terminal each include: a connection portion in contact with the capacitor element; a lead-out portion connected to the connection portion and led out from the inside of the outer package to an outer surface; and an external terminal portion connected to the lead-out portion, disposed along the outer surface, and having an exposed surface,

at least a part of a covering portion of the lead-out portion of at least one of the anode terminal and the cathode terminal, which is covered with the exterior body, has a corner portion having a chamfered shape in a cross section formed in parallel with a surface region of the outer surface from which the lead-out portion is led out.

2. The electrolytic capacitor according to claim 1,

the cross section has a corner portion of the chamfered shape at least at a boundary portion of the lead-out portion exposed from the outer surface.

3. The electrolytic capacitor according to claim 1,

the boundary portion of the leading-out portion exposed from the outer surface forms a bent portion,

the lead-out portion is connected to the external terminal portion at the bent portion,

at least the cross section corresponding to the curved portion has a corner portion of the chamfered shape on the inner side in the curved direction of the curved portion.

4. The electrolytic capacitor as recited in any one of claims 1 to 3,

in the cathode terminal, the connecting portion and the external terminal portion are provided in parallel with each other,

the cathode terminal is formed in a stepped shape by the connecting portion, the lead-out portion, and the external terminal portion.

5. The electrolytic capacitor as recited in any one of claims 1 to 4,

the anode body is provided with an anode lead and a porous body of a valve metal,

the anode lead has: a first portion embedded in the porous body, and a second portion led out to rise from the porous body,

the connection portion of the anode terminal is connected to the second portion.

6. The electrolytic capacitor as recited in any one of claims 1 to 5,

all of the corners at the cross section are the corners of the chamfered shape.

Technical Field

The present invention relates to an electrolytic capacitor including a capacitor element.

Background

An electrolytic capacitor is provided with: a capacitor element; an outer package covering the capacitor element; an anode terminal electrically connected to the anode body of the capacitor element; and a cathode terminal electrically connected to the cathode portion of the capacitor element. The anode terminal and the cathode terminal are respectively provided with: a connection portion in contact with the capacitor element; a lead-out part connected with the connecting part and led out from the inside of the outer casing to the outer surface; and an external terminal portion connected to the lead-out portion, disposed along an outer surface of the exterior body, and having an exposed surface. In patent document 1, the connecting portion and the external terminal portion are provided in parallel with each other, and a stepped cathode terminal having a stepped portion as a lead-out portion is used.

Prior art documents

Patent document

Patent document 1: japanese patent laid-open publication No. 2000-77269

Disclosure of Invention

Problems to be solved by the invention

The electrolytic capacitor is exposed to high temperature due to, for example, reflow soldering to a substrate. When the electrolytic capacitor is exposed to high temperature, the capacitor element and the package expand. In this case, stress concentrates on the interface portion where the outer package contacts the corner portion of the lead-out portion, and a crack may occur in the outer package from the interface portion as a starting point. The cracks reduce the sealing property of the electrolytic capacitor, and reduce the reliability of the electrolytic capacitor.

Means for solving the problem

One aspect of the present invention relates to an electrolytic capacitor including: a capacitor element including an anode body, a dielectric layer disposed on a surface of the anode body, and a cathode portion disposed on a surface of the dielectric layer; a package covering the capacitor element; an anode terminal electrically connected to the anode body; and a cathode terminal electrically connected to the cathode portion, wherein the anode terminal and the cathode terminal each include: a connection portion in contact with the capacitor element; a lead-out portion connected to the connection portion and led out from the inside of the exterior body to an outer surface; and an external terminal portion which is connected to the lead-out portion, is arranged along the outer surface, and has an exposed surface, wherein a corner portion having a chamfered shape in cross section, which is formed in parallel with a surface region of the outer surface from which the lead-out portion of the outer surface is led out, is formed in at least a part of a covering portion of the lead-out portion of at least one of the anode terminal and the cathode terminal, which is covered with the outer case.

Effect of invention

The present invention can suppress the occurrence of cracks in the outer package in the electrolytic capacitor.

Drawings

Fig. 1 is a front view showing an example of an electrolytic capacitor according to an embodiment of the present invention.

Fig. 2 is a longitudinal sectional view of the electrolytic capacitor of fig. 1.

Fig. 3 is a bottom view of the electrolytic capacitor of fig. 1.

Fig. 4 is an enlarged view of the X portion of fig. 3.

Fig. 5 is a front view of a main portion of the electrolytic capacitor of fig. 1 in cross section.

Fig. 6 is a perspective view of the cathode terminal in fig. 1.

Fig. 7 is a front view showing another example of the electrolytic capacitor according to the embodiment of the present invention.

Fig. 8 is a cross-sectional view of the cathode terminal on the same plane as the outer surface of the package from which the cathode terminal is led out in fig. 7.

Fig. 9 is an enlarged view of a portion Y of fig. 8.

Detailed Description

An electrolytic capacitor according to an embodiment of the present invention includes a capacitor element and an exterior covering the capacitor element, the capacitor element including: an anode body, a dielectric layer disposed on a surface of the anode body, and a cathode portion disposed on a surface of the dielectric layer. The electrolytic capacitor further includes: an anode terminal electrically connected to the anode body, and a cathode terminal electrically connected to the cathode portion. Each of the anode terminal and the cathode terminal (hereinafter, also referred to as an electrode terminal) includes: a connection portion in contact with the capacitor element; a lead-out portion connected to the connection portion and led out from the inside of the exterior body to the outer surface; and an external terminal portion which is provided so as to be connected to the lead-out portion, is arranged along an outer surface of the exterior body, and has an exposed surface. At least a part of a covering portion (hereinafter, also referred to as a covering portion a) in which a lead-out portion of at least one of the anode terminal and the cathode terminal is covered with the package has a chamfered corner portion in a cross section (hereinafter, also referred to as a cross section B) formed parallel to a surface region of an outer surface of the package in which the lead-out portion is led out.

By forming the corner portion of the lead-out portion into a chamfered shape, it is possible to alleviate concentration of stress at the interface portion where the exterior body and the corner portion of the lead-out portion are in contact with each other when the electrolytic capacitor is exposed to high temperature and expansion of the capacitor element or the like, and it is possible to suppress occurrence of cracks in the exterior body starting from the interface portion. Therefore, the sealing property of the electrolytic capacitor can be ensured, and the reliability of the electrolytic capacitor can be improved.

There is a region where the distance from the surface of the capacitor element to the outer surface of the package is short, that is, a thin region where the thickness of the package is small, and when the lead-out portion is disposed in the thin region, the above-described crack is likely to occur. Therefore, when the lead-out portion is disposed in the thin region and the cross section B of the lead-out portion has a chamfered corner, the effect of suppressing the occurrence of cracks in the package becomes remarkable.

Preferably, the cross section B has a chamfered corner at least at a boundary portion where the lead-out portion is exposed from the outer surface of the outer package. The outer package is likely to crack from a position in contact with the boundary portion of the lead-out portion. Therefore, when the cross section B has chamfered corners at the boundary portion, the effect of suppressing the occurrence of cracks in the package becomes remarkable.

The lead-out portion may be formed as a bent portion at a boundary portion exposed from the outer surface of the exterior body, and the lead-out portion may be connected to the external terminal portion at the bent portion. In this case, it is preferable that at least the cross section B corresponding to the bent portion has a chamfered corner portion on the inner side (concave portion side of the bent portion) in the bending direction of the bent portion. The outer package is likely to crack from a position contacting the inside of the bent portion in the bending direction. Therefore, when the cross section B has a chamfered corner portion on the inner side in the bending direction of the bent portion, the effect of suppressing the occurrence of cracks in the package becomes remarkable.

The cross section B of the lead-out portion may have a plurality of (e.g., 2 or 4) corners. From the viewpoint of enhancing the effect of suppressing the occurrence of cracks, it is preferable that all of the corners in the cross section B of at least a part of the covering portion a of the lead-out portion be chamfered. In addition, it is preferable that all of the corners in the cross section B are chamfered corners in the entire cover portion a.

The chamfered shape of the corner of the lead-out portion is not particularly limited, and may be, for example, an R-chamfered shape or a C-chamfered shape. The R-chamfered shape is obtained by R-chamfering in which a corner portion is cut roundly. The C-chamfered shape is obtained by C-chamfering processing of obliquely cutting off a portion of an angular point at an angle of 45 °. The R chamfering is performed, for example, in a range of R0.01 to R0.05. For example, in the case of R0.05, R chamfering is performed so that the corner portion is curved with a curvature radius of 0.05 mm. The C chamfering is performed, for example, in the range of C0.01 to C0.05. For example, in the case of C0.05, C chamfering is performed by cutting off the corner portions in the form of right isosceles triangles each having 0.05mm on both sides. The chamfering of the corner of the lead-out portion may be performed simultaneously with the formation of the electrode terminal, or may be performed after the formation of the electrode terminal.

The exposed surface of the external terminal portion of the electrode terminal is used for soldering to a substrate on which an electrolytic capacitor is to be mounted. A lead frame can be used for the counter electrode terminal. For example, copper or a copper alloy is used as a material for the lead frame.

The electrode terminal can be manufactured by, for example, preparing a predetermined die capable of forming the electrode terminal including a lead-out portion having a chamfered corner portion, and punching a metal piece using the die.

The electrode terminal may be manufactured by the following method.

The metal sheet is subjected to punching to form an intermediate body (electrode terminal before chamfering the corner of the lead-out portion). Then, a predetermined mold for chamfering a corner portion of a predetermined position (at least a portion corresponding to the lead-out portion) of the intermediate body is separately prepared. With this die, corners of the intermediate body at predetermined positions are chamfered by punching.

Hereinafter, the package and the capacitor element will be described in detail.

(outer body)

The package includes a resin material, preferably a cured product of a curable resin composition, and may include a thermoplastic resin or a composition containing the same. The exterior body can be formed by using a molding technique such as injection molding, insert molding, or compression molding. The package can be formed, for example, by filling a curable resin composition or a thermoplastic resin (composition) together with the outer surface of the capacitor element to a predetermined position so as to cover a part of the electrode terminal using a predetermined mold.

The curable resin composition may contain a filler, a curing agent, a polymerization initiator, a catalyst, and the like, in addition to the curable resin. As the curable resin, for example, a compound (for example, a monomer, an oligomer, a prepolymer, or the like) which is cured or polymerized by the action of heat can be used. Examples of the compound (or curable resin) include epoxy resin, phenol resin, urea resin, polyimide, polyamideimide, polyurethane, diallyl phthalate, and unsaturated polyester. The curable resin composition may contain a plurality of curable resins.

As the filler, for example, insulating particles (inorganic or organic) and/or fibers are preferable. Examples of the insulating material constituting the filler include insulating compounds (oxides and the like) such as silica and alumina, glass, mineral materials (talc, mica, clay and the like), and the like. One kind of the filler may be used alone, or two or more kinds may be used in combination. The curing agent, polymerization initiator, catalyst, and the like may be appropriately selected depending on the type of the curable resin.

As the thermoplastic resin, for example, polyphenylene sulfide (PPS), polybutylene terephthalate (PBT), or the like can be used. The composition containing a thermoplastic resin may contain the above-mentioned filler and the like in addition to the thermoplastic resin.

(capacitor element)

The capacitor element includes an anode body, a dielectric layer covering the anode body, and a cathode portion covering the dielectric layer.

(Anode body)

The anode body may be provided with an anode lead or a porous body of a valve metal. The anode lead has a first portion embedded in the porous body and a second portion led out to rise from the porous body, and the connection portion of the anode terminal is connected to the second portion.

The porous body is, for example, a sintered body of a valve metal. One end of the anode lead is embedded in the sintered body. The anode body is obtained, for example, by pressing a powder containing a valve metal in a state where one end portion of an anode lead is embedded in the powder to obtain a molded body having a desired shape (for example, a block shape), and then sintering the molded body. Examples of the valve metal contained in the porous body include tantalum.

Further, a foil-like or plate-like base material containing a valve metal may be used for the anode body. The surface of the base material is roughened by etching treatment or the like. Examples of the material of the substrate include a valve metal, an alloy containing a valve metal, and a compound containing a valve metal. These may be used alone, or 2 or more kinds may be used in combination. Examples of the valve metal contained in the base material include aluminum, tantalum, niobium, and titanium.

When the above-described base material is used for the anode body, the anode body includes: a region facing the cathode portion and a region not facing the cathode portion. The surface of the substrate may be roughened at least in the region facing the cathode portion. An insulating separator is formed in a region of the anode body not facing the cathode portion, adjacent to the cathode portion, so as to cover the surface of the anode body in a band-like manner, thereby restricting contact between the cathode portion and the anode body. The other part of the region of the anode body not facing the cathode portion is electrically connected to the anode terminal by welding.

(dielectric layer)

The dielectric layer comprises an oxide of a valve action metal (e.g., aluminum oxide, tantalum pentoxide, etc.). The dielectric layer is formed along the porous surface (including the inner wall surface of the hole) of the anode body. The surface of the dielectric layer is formed with a concave-convex shape corresponding to the shape of the surface of the anode body.

The dielectric layer is formed by, for example, anodizing the surface of the anode body. The anodic oxidation can be performed by a known method such as chemical conversion treatment. The chemical conversion treatment can be performed, for example, by immersing the anode body in a chemical conversion solution, immersing the surface of the anode body in the chemical conversion solution, using the anode body as an anode, and applying a voltage between the anode body and a cathode immersed in the chemical conversion solution. As the chemical conversion solution, for example, an aqueous phosphoric acid solution or the like can be used.

(cathode part)

The cathode portion includes a solid electrolyte layer covering at least a part of the dielectric layer, and a cathode lead layer covering the solid electrolyte layer. The cathode lead layer includes, for example, a carbon layer covering the solid electrolyte layer and a silver paste layer covering the carbon layer. The silver paste layer of the cathode portion is electrically connected to the connecting portion of the cathode terminal via an adhesive layer formed by a conductive adhesive.

The solid electrolyte layer contains, for example, a manganese compound or a conductive polymer. As the conductive polymer, for example, polypyrrole, polythiophene, polyaniline, a derivative thereof, and the like can be used. The solid electrolyte layer may also contain a dopant. More specifically, the solid electrolyte layer can contain poly (3, 4-ethylenedioxythiophene) (PEDOT) as a conductive polymer, and can contain polystyrene sulfonic acid (PSS) as a dopant.

The solid electrolyte layer can be formed by, for example, chemically polymerizing and/or electrolytically polymerizing a raw material monomer on the dielectric layer. The solid electrolyte layer may be formed by adhering a treatment liquid containing a conductive polymer to the dielectric layer and then drying the treatment liquid. The treatment liquid may further contain other components such as a dopant. The treatment liquid is a dispersion or solution of a conductive polymer. Examples of the dispersion medium (solvent) include water, an organic dispersion medium (solvent), and a mixture thereof.

The carbon layer may have conductivity, and for example, it is formed using a conductive carbon material such as graphite. The silver paste layer is formed using a composition containing silver powder and a binder resin (epoxy resin or the like), for example.

An example of an electrolytic capacitor according to an embodiment of the present invention will be described below with reference to fig. 1 to 6. Fig. 1 is a front view showing an example of an electrolytic capacitor according to an embodiment of the present invention. Fig. 2 is a longitudinal sectional view of the electrolytic capacitor of fig. 1. Fig. 2 shows a cross section perpendicular to side surface 6a of package 6 and along the longitudinal direction of anode lead 9. Fig. 3 is a bottom view of the electrolytic capacitor of fig. 1, as seen from the side surface 6 a. Fig. 4 is an enlarged view of the X portion of fig. 3. Fig. 5 is a front view of a main portion of the electrolytic capacitor of fig. 1 in cross section. In fig. 5, only the package 6 is shown in cross section for convenience. P1 in fig. 5 indicates a boundary portion of lead-out portion 15 exposed from side surface 6a of exterior body 6. P2 in fig. 5 indicates the inner side of the bending direction of the bent portion 20 (the concave portion side of the bent portion 20). Fig. 6 is a perspective view of the cathode terminal in fig. 1.

The electrolytic capacitor 1 includes a capacitor element 2. The capacitor element 2 includes: an anode body 3, a dielectric layer 4 disposed on the surface of the anode body 3, and a cathode portion 5 disposed on the surface of the dielectric layer 4. The electrolytic capacitor 1 includes: capacitor element 2, package 6 covering capacitor element 2, anode terminal 7 electrically connected to anode element 3, and cathode terminal 8 electrically connected to cathode portion 5. The package 6 has a substantially rectangular parallelepiped shape, and the electrolytic capacitor 1 also has a substantially rectangular parallelepiped shape. The side surface 6a of the package 6 is one of 6 side surfaces of a rectangular parallelepiped, which is the outer shape of the package 6.

The anode body 3 includes an anode lead 9 and a porous body 10 of a valve metal. The anode lead 9 has: a first portion 9a embedded in the porous body 10, and a second portion 9b drawn out to rise from the porous body 10. The porous body 10 is, for example, a porous sintered body of tantalum. The dielectric layer 4 is, for example, a layer of tantalum pentoxide.

The cathode portion 5 includes: a solid electrolyte layer covering at least a part of the dielectric layer 4, and a cathode lead-out layer covering the solid electrolyte layer. The cathode lead-out layer includes: a carbon layer covering the solid electrolyte layer, and a silver paste layer covering the carbon layer.

The anode terminal 7 includes: a connection portion 11 that contacts capacitor element 2, a lead-out portion 12 provided to be connected to connection portion 11, and an external terminal portion 13 provided to be connected to lead-out portion 12. Lead-out portion 12 is led out from the inside of exterior body 6 to side surface 6 a. The external terminal portions 13 are disposed along the side surfaces 6a of the package 6 and have exposed surfaces 13 a. The connection portion 11 of the anode terminal 7 is connected to the second portion 9b of the anode lead 9 by welding. A part of external terminal portion 13 on the side of package 6 is embedded in package 6.

The cathode terminal 8 includes: a connection portion 14 contacting the capacitor element 2, a lead-out portion 15 connected to the connection portion 14, and an external terminal portion 16 connected to the lead-out portion 15. Lead-out portion 15 is led out from the inside of exterior body 6 to side surface 6 a. External terminal portions 16 are disposed along side surfaces 6a of package 6, and have exposed surfaces 16 a. Connection portion 14 of cathode terminal 8 is electrically connected to the silver paste layer of cathode portion 5 via an adhesive layer (not shown) formed of a conductive adhesive.

In the cathode terminal 8, the connecting portion 14 and the external terminal portion 16 are provided in parallel with each other. Here, the term "parallel" means that an angle (acute angle) formed by the connecting portion 14 and the external terminal portion 16 is 0 ° or more and 10 ° or less. As shown in fig. 2 and 6, the cathode terminal 8 is formed in a stepped shape by the connecting portion 14, the lead-out portion 15, and the external terminal portion 16. Connecting portion 14 and external terminal portion 16 are located on one side of side surface 6a of package 6 as viewed from capacitor element 2. The lead-out portion 15 has a bent portion 19 at a boundary portion with the connecting portion 14, and has a bent portion 20 at a boundary portion with the external terminal portion 16. A part of the bent portion 20 is exposed to the outside from the side surface 6a of the exterior body 6.

A cross section B of the lead-out portion 15 formed parallel to the side surface 6a of the lead-out portion 15 of the package 6 has a chamfered corner portion 17. The chamfered shape of the corner portion 17 is an R-chamfered shape. The radius of curvature of the corner portion 17 of the R-chamfered shape in the cross section B is, for example, 0.01mm to 0.05 mm.

In the entire covering portion a of lead-out portion 15 covered with exterior body 6, all of the corner portions in cross section B of lead-out portion 15 are chamfered corner portions 17. For example, the cross section B of the lead-out portion 15 at the boundary portion P1 exposed from the side surface 6a of the package 6 has two chamfered corner portions 17. The cross section B corresponding to the curved portion 20 has two chamfered corners 17 on the inner side P2 and the outer side in the curved direction of the curved portion 20.

Lead-out portion 15 of second-order cathode terminal 8 is disposed in a thin region where the thickness of case 6 is small (a region where the distance from side surface 6a of case 6 to capacitor element 2 is short). The outer package is likely to crack from an interface portion where the thin-walled region contacts with a corner portion of the lead-out portion of the cathode terminal. Therefore, the effect of suppressing the occurrence of cracks in the exterior body can be remarkably obtained by providing the chamfered corner portion 17 in the cross section B at the lead-out portion 15 of the cathode terminal 8 disposed in the thin region.

Preferably, at least at a boundary portion P1 where lead-out portion 15 is exposed from side surface 6a of outer package 6, cross section B has chamfered corner 17. The outer package is likely to crack from a position in contact with the boundary portion P1 of the lead-out portion. Therefore, the effect of suppressing the occurrence of cracks in the exterior body can be remarkably obtained by providing the corner portion 17 having the chamfered shape in the cross section B at the boundary portion P1.

As shown in fig. 1 and 2, a part of external terminal portion 16 on the side of exterior body 6 is embedded in exterior body 6. In this case, as shown in fig. 5, bent portion 20 is formed at boundary portion P1 of lead-out portion 15 exposed from side surface 6a of outer package 6. That is, the curved portion 20 includes the boundary portion P1. The lead-out portion 15 is connected to the external terminal portion 16 at the bent portion 20. In this case, it is preferable that at least the cross section B corresponding to the curved portion 20 has the chamfered corner 17 on the inner side (the concave portion side of the curved portion 20) P2 in the curved direction of the curved portion 20. The outer package is likely to crack from a position in contact with the inside P2 in the bending direction of the bent portion. Therefore, the effect of suppressing the occurrence of cracks in the exterior body can be remarkably obtained by providing the corner portion 17 having the chamfered shape in the cross section B at the inner side P2 in the bending direction of the bent portion 20.

In the present embodiment, the external terminal portion 16 of the cathode terminal 8 has a chamfered corner portion 18 provided in connection with the chamfered corner portion 17 of the lead-out portion 15. The corner of the external terminal portion may not have a chamfered shape.

In the present embodiment, all of the corners of the cross section B of the lead-out portion 15 are chamfered corners 17 in the entire cover portion a of the lead-out portion 15 covered with the outer package 6, but the cross section B of the lead-out portion may have chamfered corners in at least a part of the cover portion a. The corner portions 17 and 18 have an R-chamfered shape, but the chamfered shape of the corner portions may be a C-chamfered shape. The corner of lead-out portion 12 of anode terminal 7 is not chamfered, but the lead-out portion of the anode terminal may have a chamfered corner.

Next, another example of the electrolytic capacitor according to the embodiment of the present invention will be described with reference to fig. 7 to 9. Fig. 7 is a front view showing another example of the electrolytic capacitor according to the embodiment of the present invention. Fig. 8 is a cross-sectional view of the cathode terminal on the same surface as side surface 26B of the package from which the cathode terminal is led out in fig. 7, and shows cross-section B of lead-out portion 35 at boundary portion P3 exposed from side surface 26B of package 26. Fig. 9 is an enlarged view of a portion Y of fig. 8.

The electrolytic capacitor 21 includes a capacitor element 22. The capacitor element 22 has the same structure as the capacitor element 2 in fig. 1 and 2. The electrolytic capacitor 21 includes: capacitor element 22, package 26 covering capacitor element 22, anode terminal 27 electrically connected to the anode of capacitor element 22, and cathode terminal 28 electrically connected to the cathode of capacitor element 22. Outer package 26 has a substantially rectangular parallelepiped shape, and electrolytic capacitor 21 also has a substantially rectangular parallelepiped shape. Side surfaces 26a to 26c of package 26 are 3 side surfaces out of 6 side surfaces of a rectangular parallelepiped, which is the outer shape of package 26. The side surfaces 26a and 26b are located on mutually opposite sides and have a perpendicular relationship to the side surfaces 26c, respectively.

The anode terminal 27 includes: a connection portion 31 contacting the capacitor element 22, a lead-out portion 32 connected to the connection portion 31, and an external terminal portion 33 connected to the lead-out portion 32. Lead-out portion 32 is led out from the inside of package 26 to side surface 26 a. External terminal portions 33 are disposed along side surface 26c from side surface 26a of package 26. The portion of the external terminal portion 33 disposed along the side surface 26c of the package 26 has an exposed surface 33 a. The portion of the external terminal portion 33 having the exposed surface 33a is disposed in a recess provided in the side surface 26c of the package 26. The connection portion 31 of the anode terminal 27 is connected to the second portion 29b of the anode wire of the capacitor element 22 by welding.

The cathode terminal 28 includes: a connection portion 34 that contacts the capacitor element 22, a lead-out portion 35 provided to be connected to the connection portion 34, and an external terminal portion 36 provided to be connected to the lead-out portion 35. Lead-out portion 35 is led out from the inside of package 26 to side surface 26 b. External terminal portions 36 are disposed along side surface 26c from side surface 26b of package 26. The portion of the external terminal portion 36 disposed along the side surface 26c of the package 26 has an exposed surface 36 a. The portion of the external terminal portion 36 having the exposed surface 36a is disposed in a recess provided in the side surface 26c of the package 26. The connecting portion 34 of the cathode terminal 28 is electrically connected to the silver paste layer of the cathode portion of the capacitor element 22.

As shown in fig. 7, the cathode terminal 28 is formed into a substantially コ shape by the connecting portion 34, the lead-out portion 35, and the external terminal portion 36. The capacitor element 22 is located between a contact portion of the connecting portion 34 with the capacitor element 22 and a portion of the external terminal portion 36 having the exposed surface 36 a. The lead-out portion 35 has a bent portion 39 at a boundary with the connecting portion 34, and has a bent portion 40 at a boundary with the external terminal portion 36. The bent portion 40 is exposed to the outside from the side surface 26b of the package 26.

As shown in fig. 9, a cross section B of lead-out portion 35 formed parallel to side surface 26B from which lead-out portion 35 of package 26 is led out has chamfered corner 37. The chamfered shape of the corner portion 37 is an R-chamfered shape. In the entire covering portion a of the lead-out portion 35 covered with the exterior body 26, all of the corner portions in the cross section B of the lead-out portion 35 are chamfered corner portions 37. For example, the cross section B of the lead-out portion 37 at the boundary portion P3 exposed from the side surface 26B of the package 26 has 4 chamfered corner portions 37.

The bent portion 40 is formed at the portion of the lead portion 35 exposed to the outside from the side surface 26b of the package 26. That is, bent portion 40 does not include boundary portion P3 of lead-out portion 37 exposed from side surface 26b of package 26. The lead-out portion 35 is connected to the external terminal portion 36 at the bent portion 40. In this case, it is preferable that the cross section B has a chamfered corner 37 at least at a boundary portion P3 of the lead-out portion 37 exposed from the side surface 26B of the package 26.

In the present embodiment, all of the corners of the cross section B of the lead-out portion 35 are chamfered corners 37 in the entire cover portion a of the lead-out portion 35 covered with the outer package 26, but the cross section B of the lead-out portion may have chamfered corners in at least a part of the cover portion a. The corner 37 has an R-chamfered shape, but the corner may have a C-chamfered shape. The corner of lead-out portion 32 of anode terminal 27 is not chamfered, but the lead-out portion of the anode terminal may have a chamfered corner.

Industrial applicability

The electrolytic capacitor according to the present invention can be used in various applications in which high reliability is required even when exposed to a high-temperature environment.

-description of symbols-

1. 21: electrolytic capacitor, 2, 22: capacitor element, 3: anode body, 4: dielectric layer, 5: cathode portion, 6, 26: package, 6a, 26b, 26 c: side surface of outer package, 7, 27: anode terminal, 8, 28: cathode terminal, 9: anode lead, 9 a: first portion, 9b, 29 b: second part, 10: porous body, 11, 31: connection portion of anode terminal, 12, 32: lead-out portion of anode terminal, 13, 33: external terminal portion of anode terminal, 13a, 33 a: exposed surface of external terminal portion of anode terminal, 14, 34: connection portion of cathode terminal, 15, 35: lead-out portion of cathode terminal, 16, 36: external terminal portion of cathode terminal, 16a, 36 a: exposed surface of external terminal portion of cathode terminal, 17, 37: corner of lead-out portion of cathode terminal, 18: corner portions of external terminal portions of cathode terminals, 19, 20, 39, 40: and a bent portion of the lead-out portion of the cathode terminal.