WO2023189736A1

WO2023189736A1 - Electrolytic capacitor

Info

Publication number: WO2023189736A1
Application number: PCT/JP2023/010624
Authority: WO
Inventors: 順一粕谷
Original assignee: 株式会社村田製作所
Priority date: 2022-03-28
Filing date: 2023-03-17
Publication date: 2023-10-05

Abstract

This electrolytic capacitor 1 comprises: a laminate 30 which has a first surface 30a and in which a plurality of capacitor elements 20 are laminated, each capacitor element including a valve action metal substrate 4 having a core portion 4a and a porous portion 4b formed along the surface of the core portion, a dielectric layer 5 formed on the porous portion 4b, a solid electrolyte layer 7a formed on the dielectric layer 5, and a conductive layer 7b formed on the solid electrolyte layer 7a; a first conductive resin part 21 which is provided on the first surface 30a of the laminate 30, and to which the core portion 4a of the capacitor element 20 is connected; and a first lead frame 11 connected to the core portion 4a with the first conductive adhesive part 21 therebetween.

Description

Electrolytic capacitor

The present invention relates to an electrolytic capacitor.

Patent Document 1 discloses a solid electrolytic capacitor.
Embodiment 2 of the solid electrolytic capacitor disclosed in Patent Document 1 describes a structure in which three chip-type solid electrolytic capacitors are stacked. A structure is described in which an anode lead-out body is exposed from each capacitor element, and an anode terminal is joined to the anode lead-out body by laser welding.

Japanese Patent Application Publication No. 2001-85273

The anode lead-out body of the solid electrolytic capacitor of Patent Document 1 is made of a valve metal. Furthermore, a member called a lead frame is used as the anode terminal. When a valve metal serving as an anode lead-out body and a lead frame serving as an anode terminal are welded as in Patent Document 1, the joint is hard and there is no flexibility at the joint. Therefore, stress caused by thermal expansion of each member during reflow may cause the lead frame and the valve metal to become disconnected, resulting in an increase in LC (leakage current) in the electrolytic capacitor.

The present invention has been made to solve the above-mentioned problems, and provides an electrolytic capacitor in which a lead frame and a valve metal are electrically connected to relieve stress such as thermal stress. The purpose is to

The electrolytic capacitor of the present invention includes a valve metal base having a core portion and a porous portion formed along the surface thereof, a dielectric layer formed on the porous portion, and a dielectric layer formed on the dielectric layer. a laminate in which a plurality of capacitor elements including a formed solid electrolyte layer and a conductive layer formed on the solid electrolyte layer are stacked and have a first surface; , a first conductive resin part to which the core part of the capacitor element is connected, and a first lead frame connected to the core part via the first conductive resin part.

According to the present invention, it is possible to provide an electrolytic capacitor in which a lead frame and a valve metal are electrically connected, and stress such as thermal stress is relaxed.

FIG. 1 is a perspective view schematically showing an example of an electrolytic capacitor of the present invention. FIG. 2 is a side view of the electrolytic capacitor shown in FIG. 1 viewed from the first end surface. FIG. 3 is a bottom view of the electrolytic capacitor shown in FIG. 1. FIG. 4 is a cross-sectional view taken along line AA of the electrolytic capacitor shown in FIG. FIG. 5 is a cross-sectional view schematically showing the vicinity of the valve metal base on the first surface of the laminate. FIG. 6 is a process diagram schematically showing a part of the manufacturing process of an electrolytic capacitor. FIG. 7 is a process diagram schematically showing a part of the manufacturing process of an electrolytic capacitor. FIG. 8A is a process diagram schematically showing a part of the manufacturing process of an electrolytic capacitor. FIG. 8B is a process diagram schematically showing a part of the manufacturing process of an electrolytic capacitor. FIG. 9A is a process diagram schematically showing a part of the manufacturing process of an electrolytic capacitor. FIG. 9B is a process diagram schematically showing a part of the manufacturing process of an electrolytic capacitor. FIG. 9C is a process diagram schematically showing a part of the manufacturing process of an electrolytic capacitor. FIG. 10 is a LT plane cross-sectional view of an electrolytic capacitor according to another embodiment. FIG. 11 is a LT plane cross-sectional view of an electrolytic capacitor according to another embodiment. FIG. 12 is a process diagram schematically showing a part of the manufacturing process of the electrolytic capacitor shown in FIG. 11.

The solid electrolytic capacitor of the present invention will be explained below.
However, the present invention is not limited to the following configuration, and can be modified and applied as appropriate without changing the gist of the present invention. Note that the present invention also includes a combination of two or more of the individual desirable configurations of the present invention described below.

FIG. 1 is a perspective view schematically showing an example of the electrolytic capacitor of the present invention, FIG. 2 is a side view of the electrolytic capacitor shown in FIG. FIG. 3 is a bottom view of an electrolytic capacitor.

An electrolytic capacitor 1 is shown in FIGS. 1, 2, and 3. As shown in FIG.
The electrolytic capacitor 1 has a rectangular parallelepiped shape as a whole, and has a length direction (L direction), a width direction (W direction), and a thickness direction (T direction).
The electrolytic capacitor 1 has, as its outer surface, a first end surface 1a and a second end surface 1b that face each other in the length direction. The electrolytic capacitor 1 has, as its outer surfaces, a bottom surface 1c and a top surface 1d that face each other in the thickness direction. Further, the electrolytic capacitor 1 includes, as its outer surface, a first side surface 1e and a second side surface 1f that face each other in the width direction.

In this specification, the surface along the length direction (L direction) and thickness direction (T direction) of the electrolytic capacitor is referred to as the LT surface, and the surface along the length direction (L direction) and width direction (W direction) is referred to as the LT surface. The plane along the width direction (W direction) and the thickness direction (T direction) is called the WT plane.

A first lead frame 11 is formed on the first end surface 1a of the electrolytic capacitor 1, and a second lead frame 13 is formed on the second end surface 1b. Further, the first lead frame 11 is formed continuously from the first end surface 1a to the bottom surface 1c of the electrolytic capacitor 1, and the second lead frame 13 is formed continuously from the second end surface 1b to the bottom surface 1c of the electrolytic capacitor 1. It is formed by

In the electrolytic capacitor 1, the periphery of a stacked body (not shown in FIG. 1) in which a plurality of capacitor elements are stacked is sealed with a sealing resin 8, and the surface of the sealing resin 8 and the first lead frame 11 are sealed. A rectangular parallelepiped-shaped resin molded body 9 is constituted by the front surface and the surface of the second lead frame 13 serving as the outer surface.

The surface of the first lead frame 11 and the surface of the sealing resin 8 constitute the first end surface 1a of the electrolytic capacitor 1 (see FIG. 2). Further, the surface of the second lead frame 13 constitutes the second end surface 1b of the electrolytic capacitor 1 together with the surface of the sealing resin 8.
Furthermore, the surface of the first lead frame 11, the surface of the sealing resin 8, and the surface of the second lead frame 13 together constitute the bottom surface 1c of the electrolytic capacitor 1 (see FIG. 3).

In addition, in the electrolytic capacitor of the present invention, the periphery of the laminate is sealed with a sealing resin, and a rectangular parallelepiped-shaped resin molded body is formed in which the surface of the sealing resin and the surface of the first lead frame are the outer surfaces. is preferred. Further, in the electrolytic capacitor of the present invention, the periphery of the laminate is sealed with a sealing resin, and the surface of the sealing resin, the surface of the first lead frame, and the surface of the second lead frame are the outer surfaces. It is preferable to construct a rectangular parallelepiped-shaped resin molded body.

The shape of the electrolytic capacitor of the present invention and the shape of the resin molded body constituting the electrolytic capacitor of the present invention are not particularly limited, and any three-dimensional shape can be adopted. The shape of the electrolytic capacitor and the shape of the resin molding are preferably rectangular parallelepipeds. In addition, the term "cuboid shape" does not mean a perfect rectangular parallelepiped; the surfaces forming the electrolytic capacitor and the resin molded body may not be orthogonal to other surfaces and may have a taper, or may have an angular shape. The shape may be chamfered.

FIG. 4 is a cross-sectional view taken along line AA of the electrolytic capacitor shown in FIG.
The capacitor element 20 includes a valve metal base 4 having a core portion and a porous portion formed along the surface thereof, a dielectric layer 5 formed on the porous portion, and a dielectric layer 5 formed on the dielectric layer 5. The conductive layer 7b (carbon layer 7b1 and metal layer 7b2) is formed on the solid electrolyte layer 7a.
A plurality of capacitor elements 20 are stacked to form a laminate 30, and the periphery of the laminate 30 is sealed with a sealing resin 8 to form a resin molded body 9. In the laminate 30, the stacked capacitor elements 20 may be bonded to each other via a conductive adhesive (not shown).

Examples of the valve metal that constitutes the valve metal base include simple metals such as aluminum, tantalum, niobium, titanium, zirconium, magnesium, and silicon, and alloys containing these metals. Among these, aluminum or aluminum alloy is preferred.

Although the shape of the valve metal base is not particularly limited, it is preferably flat, and more preferably foil-like. Further, the porous portion is preferably an etched layer etched with hydrochloric acid or the like.
The thickness of the valve metal base before etching is preferably 60 μm or more, and preferably 180 μm or less. Further, the thickness of the valve metal base (core portion) that is not etched after the etching treatment is preferably 10 μm or more, and preferably 70 μm or less. The thickness of the porous portion is designed in accordance with the withstand voltage and capacitance required of the electrolytic capacitor, but it is preferable that the total thickness of the porous portions on both sides of the valve metal base is 10 μm or more, and 120 μm or less. It is preferable that

The dielectric layer is preferably made of an oxide film of the valve metal. For example, when aluminum foil is used as a valve metal base, it is anodized to form a dielectric layer by anodizing in an aqueous solution containing boric acid, phosphoric acid, adipic acid, or their sodium salts, ammonium salts, etc. A film can be formed.
The dielectric layer is formed along the surface of the porous portion to form pores (recesses). The thickness of the dielectric layer is designed according to the withstand voltage and capacitance required of the electrolytic capacitor, and is preferably 3 nm or more, and preferably 200 nm or less.

At the anode side end of the capacitor element 20, a mask layer 40 is provided around the valve metal base 4 and the dielectric layer 5. A part of the surface of the mask layer 40 constitutes the first surface 30a of the laminate 30 together with the surfaces of the core and porous portion of the valve metal base 4. The first surface 30a of the laminate 30 corresponds to the first end surface 1a of the electrolytic capacitor 1. The first surface 30a of the laminate 30 is the anode side end surface of the laminate.

A first conductive resin part 21 to which each core part of the capacitor element 20 is connected is provided on the first surface 30a of the laminate 30. Since the first conductive resin part 21 to which each core part of the capacitor element 20 is connected is integrated, the anodes of the plurality of capacitor elements 20 are collected by the first conductive resin part 21. .

The first conductive resin part 21 is further connected to the first lead frame 11. Since the first conductive resin part 21 is connected to the core part of the capacitor element 20 and the first lead frame 11, the first lead frame 11 is connected to the core part of the capacitor element 20 and the first conductive resin part. This means that they are connected via 21.

In the electrolytic capacitor of the present invention, the first lead frame and the core of the capacitor element are not welded but are connected via the first conductive resin part. Since the connection using the first conductive resin part is a connection using resin, it is a joining form in which the joint portion is more flexible than welding. Therefore, problems caused by the first lead frame and the core becoming disconnected due to stress due to thermal expansion of each member during reflow can be prevented.
Further, since the first conductive resin part is made of a conductive material, electrical connection between the first lead frame and the core part is also ensured. From the above, the electrolytic capacitor of the present invention is an electrolytic capacitor in which the first lead frame and the valve metal are electrically connected, and stress such as thermal stress is relaxed.

As the first lead frame, aluminum, copper, nickel, chromium, cobalt, or an alloy containing them can be used.

The first conductive resin portion is preferably a conductive resin electrode layer containing a conductive component and a resin component.
The conductive component preferably contains Ag, Cu, Ni, Sn, etc. as a main component, and the resin component preferably contains an epoxy resin, phenol resin, etc. as a main component.
In particular, it is preferable that the first conductive resin portion contains Ag. A conductive resin electrode layer containing Ag can reduce ESR because Ag has a low specific resistance.
Moreover, it is preferable that the first conductive resin part is a printed resin electrode layer formed by screen printing an electrode paste. When the first conductive resin part is a printed resin electrode layer, the first conductive resin part can be made flat compared to a case where the electrode layer is formed by dipping into electrode paste.
Furthermore, instead of screen printing, the first conductive resin portion may be formed by applying electrode paste using a dispenser.

The electrode paste for forming the first conductive resin portion may contain an organic solvent, and it is preferable to use a glycol ether solvent as the organic solvent. Examples include diethylene glycol monobutyl ether and diethylene glycol monophenyl ether.
Additionally, additives may be used as necessary. Additives are useful in adjusting the rheology of the electrode paste, especially the thixotropy.

Preferably, a contact layer in direct contact with the core is provided on the first surface of the laminate, and the core is connected to the first conductive resin part via the contact layer.
Hereinafter, a mode in which the core portion is connected to the first conductive resin portion via a contact layer will be described.

FIG. 5 is a cross-sectional view schematically showing the vicinity of the valve metal base on the first surface of the laminate.
FIG. 5 is also a sectional view schematically showing a region surrounded by a dotted line B in the lower right portion of FIG.
The valve metal base 4 has a core portion 4a and a porous portion 4b formed along the surface of the core portion 4a. The end portion of the valve metal base 4 is exposed on the first surface 30a of the laminate 30.
A dielectric layer 5 is formed on the surface of the porous portion 4b.

FIG. 5 shows a contact layer 31 that is in direct contact with the core portion 4a. The first conductive resin portion 21 exists around the contact layer 31, and the core portion 4a is connected to the first conductive resin portion 21 via the contact layer 31.
The contact layer 31 is preferably an electrode layer containing at least one selected from the group consisting of Cu, Ni, Sn, Ag, Zn, and Au, and is preferably an electrode layer made of Cu.

By providing the contact layer, the connectivity between the core part and the first conductive resin part can be improved. For example, if the core is aluminum and the main conductive component contained in the first conductive resin part is Ag, it is better to connect aluminum and Ag through another material than to connect them directly. may increase connectivity. For example, if Cu or Zn is used in the contact layer and aluminum and Ag are connected through Cu or Zn, the connectivity between the core made of aluminum and the first conductive resin part containing Ag can be improved. I can do it.

Further, it is preferable that the thickness of the contact layer 31 at the portion formed in the core portion 4a is thicker than the thickness at the portion where the contact layer 31 is formed in the porous portion 4b.
The thickness of the contact layer 31 is determined as the thickness of the contact layer 31 in the normal direction of the first surface 30a of the stacked body 30. Further, the thickness of the contact layer 31 formed in the core portion 4a of the valve metal base 4 and the porous portion 4b of the valve metal base 4 is determined as the thickness at the thickest point at each location. In FIG. 5, the thicknesses of the contact layers 31 formed in the core portion 4a of the valve metal base 4 and the porous portion 4b of the valve metal base 4 are indicated by double arrows T ₁ and T ₂ , respectively.
The direction indicated by the double-headed arrows T ₁ and T ₂ is the normal direction of the first surface 30 a of the laminate 30 .

When forming the contact layer 31 on the first surface 30a of the laminate 30, the contact layer 31 is easily formed in the core part 4a, and the contact layer 31 is not formed in the porous part 4b, which is more fragile than the core part 4a. Hateful. Therefore, the thickness of the contact layer 31 becomes thicker in the core portion 4a.
If the contact layer is thicker in the core, the contact area with the first conductive resin part formed on the contact layer increases compared to when the contact layer is flat, and the contact layer becomes thicker in the core. Since the adhesion with the conductive resin portion is improved, the ESR can be sufficiently lowered.
Furthermore, since the connection strength between the contact layer and the first conductive resin portion is high, the terminal fixing strength when an electrolytic capacitor is mounted can also be increased.

The thickness of the contact layer formed on the core portion is preferably 0.3 μm or more and 30 μm or less. When the thickness of the contact layer is within the above range, the ESR can be lowered, and the terminal fixing strength when an electrolytic capacitor is mounted can be increased.

The contact layer is preferably a layer formed by an aerosol deposition method. In the aerosol deposition method, fine metal particles are injected from a nozzle provided at the tip of an aerosol generator, and collide with the first surface of the laminate to form a contact layer.
In the aerosol deposition method, the oxide film on the surface of the metal forming the core is removed by the collision of an aerosol with the core, the metal is exposed, and the contact layer is bonded to the exposed metal. In the aerosol deposition method, the removal of the oxide film and the bonding of the contact layer are performed successively in a non-oxidizing atmosphere, so it is possible to prevent the formation of an oxide film at the bonding interface between the contact layer and the core. can. Furthermore, since the resistance at the bonding interface between the contact layer and the core is low, the ESR of the electrolytic capacitor can be lowered.
In particular, when the valve metal base is made of aluminum, an oxide film is likely to form on the surface of the core, so the effect of providing the contact layer by the aerosol deposition method is suitably exhibited.

In addition to the aerosol deposition method, methods such as sputtering and vapor deposition can also be used as a method for providing the contact layer.

Up to this point, the structure related to the anode of the electrolytic capacitor has been described. Next, the structure related to the cathode of the electrolytic capacitor and other structures constituting the electrolytic capacitor will be described with reference to FIG. 4.

The capacitor element 20 includes a solid electrolyte layer 7a formed on the dielectric layer 5 and a conductive layer 7b formed on the solid electrolyte layer 7a. An electrolytic capacitor in which a solid electrolyte layer is provided as part of the cathode can be said to be a solid electrolytic capacitor.

The cathode side end of the valve metal base 4 constituting the capacitor element 20 is covered with a dielectric layer 5 or otherwise insulated, so that the core 4a of the valve metal base 4 and the solid electrolyte are It is not in direct contact with layer 7a or conductive layer 7b.

Examples of the material constituting the solid electrolyte layer include conductive polymers having skeletons such as pyrroles, thiophenes, and anilines. Examples of conductive polymers with thiophene skeletons include PEDOT [poly(3,4-ethylenedioxythiophene)], and PEDOT:PSS complexed with polystyrene sulfonic acid (PSS) as a dopant. It may be.

For example, the solid electrolyte layer is formed by forming a polymer film of poly(3,4-ethylenedioxythiophene) or the like on the surface of the dielectric layer using a treatment liquid containing a monomer such as 3,4-ethylenedioxythiophene. The dielectric layer is formed by applying a dispersion of a polymer such as poly(3,4-ethylenedioxythiophene) to the surface of the dielectric layer and drying it. Note that after forming the solid electrolyte layer for the inner layer that fills the pores (recesses), it is preferable to form the solid electrolyte layer for the outer layer that covers the entire dielectric layer.
The solid electrolyte layer can be formed in a predetermined area by applying the above-mentioned treatment liquid or dispersion onto the dielectric layer by sponge transfer, screen printing, spray coating, dispenser, inkjet printing, or the like. The thickness of the solid electrolyte layer is preferably 2 μm or more, and preferably 20 μm or less.

The conductive layer is preferably a carbon layer, a graphene layer, or a silver layer formed by applying a conductive paste such as carbon paste, graphene paste, or silver paste. Further, it may be a composite layer in which a silver layer is provided on a carbon layer or a graphene layer, or a mixed layer in which carbon paste, graphene paste, and silver paste are mixed.

The conductive layer can be formed by forming a conductive paste such as carbon paste on the solid electrolyte layer by sponge transfer, screen printing, spray coating, dispenser printing, inkjet printing, or the like.
FIG. 4 shows a carbon layer 7b1 and a metal layer 7b2 as the conductive layer 7b.

The electrolytic capacitor of the present invention includes a second conductive resin part provided on the second surface of the laminate to which the conductive layer of the capacitor element is connected, and a second lead connected to the second conductive resin part. Preferably, the device further includes a frame.

In the electrolytic capacitor 1 shown in FIG. 4, a second conductive resin portion 23 is formed on the second surface 30b of the laminate 30, and the second conductive resin portion 23 is connected to the conductive layer 7b of the capacitor element 20. has been done. Since the second conductive resin part 23 to which the conductive layer 7b of the capacitor element 20 is connected is integrated, the cathodes of the plurality of capacitor elements 20 are collected by the second conductive resin part 23. The second surface 30b of the laminate 30 is the end surface of the laminate on the cathode side.

The second conductive resin part 23 is further connected to the second lead frame 13. Since the second conductive resin portion 23 is connected to the conductive layer 7b of the capacitor element 20 and the second lead frame 13, the second lead frame 13 is connected to the conductive layer 7b of the capacitor element 20 and the second conductive layer 7b. This means that they are connected via the resin portion 23.

The connection between the second lead frame and the conductive layer of the capacitor element can also be made by directly bonding the second lead frame and the conductive layer of the capacitor element without using the second conductive resin part. . However, when directly bonding the second lead frame and the conductive layer of the capacitor element, the bonding area may be insufficient and the resistance between the second lead frame and the conductive layer of the capacitor element may become high. On the other hand, if the second lead frame and the conductive layer of the capacitor element are connected through the second conductive resin part, the second conductive resin part may enter the gap between the capacitor elements. This increases the connection area between the second conductive resin portion and the conductive layer of the capacitor element. Furthermore, the connection area between the second conductive resin portion and the second lead frame also increases. Therefore, the resistance between the second lead frame and the conductive layer of the capacitor element can be reduced. Furthermore, since the connection using the second conductive resin portion is a connection using resin, the connection is a joining form in which the joint portion is more flexible than welding. Therefore, problems caused by the second lead frame and the conductive layer becoming disconnected due to stress due to thermal expansion of each member during reflow can be prevented.

As the second lead frame, the materials and shapes exemplified for the first lead frame can be used. The material and shape of the second lead frame and the first lead frame may be the same or different.

As the second conductive resin part, a conductive resin electrode layer containing a conductive component and a resin component, which is exemplified as a form of the first conductive resin part, can be used. The material and shape of the second conductive resin part and the first conductive resin part may be the same or different.

Furthermore, it is not necessary to provide a contact layer on the second surface of the laminate. This is because, in many cases, sufficient connectivity between the conductive layer and the second conductive resin portion can be ensured even without providing a contact layer.

Note that the method for drawing out the cathode from the capacitor element in the electrolytic capacitor of the present invention is not limited to the method using the second conductive resin part and the second lead frame, and may be any other conventionally known drawing method. A method may also be used. For example, a method may be used in which a metal foil is used as a conductive layer and drawn out to the end face of a resin molded body, and then a cathode external electrode consisting of a resin electrode layer and a plating layer is formed.

A first conductive resin part and a first lead frame are provided on the first surface of the laminate in which a plurality of capacitor elements are laminated, and if necessary, a second conductive resin part and a first lead frame are provided on the second surface of the laminate. It is preferable that a second lead frame is provided and the periphery of the second lead frame is further sealed with a sealing resin, so that the entire resin molded body has a rectangular parallelepiped shape.

The sealing resin constituting the resin molded article contains at least a resin, and preferably contains a resin and a filler. As the resin, it is preferable to use insulating resins such as epoxy resins, phenol resins, polyimide resins, silicone resins, polyamide resins, and liquid crystal polymers. As for the form of the sealing resin, both solid resin and liquid resin can be used. Further, as the filler, it is preferable to use inorganic particles such as silica particles, alumina particles, and metal particles. It is more preferable to use a material containing silica particles in the solid epoxy resin and phenol resin.
As a method for molding the resin molded body, when a solid sealing material is used, it is preferable to use a resin mold such as a compression mold or a transfer mold, and it is more preferable to use a compression mold. Moreover, when using a liquid sealant, it is preferable to use a molding method such as a dispensing method or a printing method.

In the thus obtained electrolytic capacitor, in a cross section (LT plane cross section) obtained by cutting the electrolytic capacitor along the length direction and thickness direction, the first lead frame is located at the first end surface (anode side end surface) of the electrolytic capacitor. ) preferably has an L-shape with the long sides.
The short side of the L shape becomes the bottom surface of the electrolytic capacitor. The bottom surface of the electrolytic capacitor becomes the mounting surface when mounting the electrolytic capacitor on a board or the like. It is preferable that the length of the short side of the L-shape is long enough to ensure that the area of the first lead frame on the bottom surface of the electrolytic capacitor is large enough for mounting.

In addition, in a cross section (LT cross section) obtained by cutting the electrolytic capacitor along the length direction and the thickness direction, the second lead frame has an L-shape in which the second end surface (cathode side end surface) of the electrolytic capacitor is the long side. It is preferable to have.

FIG. 4 shows a LT plane cross-sectional view of the electrolytic capacitor. FIG. 4 shows that the first lead frame 11 and the second lead frame 13 each have an L-shape in the LT cross section of the electrolytic capacitor.
In FIG. 4, the L-shaped short side portion of the first lead frame 11 is drawn so as to be in contact with the first conductive resin portion 21, the mask layer 40, and the sealing resin 8. The sealing resin 8 may enter between the mask layer 40 and the first lead frame 11 and the mask layer 40 and the first lead frame 11 may be bonded together via the sealing resin 8.
In FIG. 4, the first lead frame 11 has an inverted L shape with the short side facing left, but this shape is also included in the L shape.

Next, an example of a method for manufacturing an electrolytic capacitor will be described.
6, FIG. 7, FIG. 8A, FIG. 8B, FIG. 9A, FIG. 9B, and FIG. 9C are process diagrams schematically showing a part of the manufacturing process of an electrolytic capacitor.
FIG. 6 shows a series of lead frames for use in manufacturing three electrolytic capacitors. The right side is the first lead frame series 110, and the left side is the second lead frame series 120.
The first lead frame series 110 is provided with a plate-like part 111 that becomes a first lead frame of an electrolytic capacitor, and a connecting part 112 that connects the plate-like part 111. There are three plate-like parts 111, and each plate-like part 111 is coated with a conductive paste 113 that becomes a first conductive resin part.
The second lead frame series 120 is provided with a plate-like part 121 that becomes a second lead frame of the electrolytic capacitor, and a connecting part 122 that connects the plate-like part 121. There are three plate-like parts 121, and each plate-like part 121 is coated with a conductive paste 123 that becomes a second conductive resin part.

FIG. 7 shows a state in which the laminate 30 is placed on the first lead frame series 110 and the second lead frame series 120.
The laminate 30 is placed between the plate-like part 111 that becomes the first lead frame and the plate-like part 121 that becomes the second lead frame.
It is preferable that the first surface 30a of the laminate 30 is provided with a contact layer that is in direct contact with the core. Illustration of the contact layer is omitted.

In FIG. 8A, the plate-like part 111 of the first lead frame series 110 and the plate-like part 121 of the second lead frame series 120 are bent toward the first surface 30a and the second surface 30b of the laminate 30, respectively. It shows the condition. FIG. 8B is a side view of the state shown in FIG. 8A viewed from the side of the laminate 30.
Since a conductive paste is applied to each plate-like part, the end face of the laminate and the plate-like part are connected with the conductive paste.
The plate-shaped portion 111 of the first lead frame series 110 becomes the first lead frame 11, and the conductive paste 113 becomes the first conductive resin portion 21.
The plate-shaped portion 121 of the second lead frame series 120 becomes the second lead frame 13, and the conductive paste 123 becomes the second conductive resin portion 23.

FIG. 9A shows a state in which the periphery of the laminate 30 is sealed with a sealing resin 8 to form a resin molded body 9. 9B is a side view of the state shown in FIG. 9A viewed from the side surface of the resin molded body 9, and FIG. 9C is an end view of the state shown in FIG. 9A viewed from the first end surface side of the resin molded body 9.
In FIG. 9B, the stacked body 30 inside the sealing resin 8 is simplified and shown by a dotted line.
As shown in FIG. 9C, the first lead frame 11 is exposed on the first end surface of the resin molded body 9.
Through the steps up to this point, the electrolytic capacitors are connected by the connecting portions of the lead frame series, so that the electrolytic capacitors can be obtained by cutting the connecting portions into individual pieces.

(Another embodiment of electrolytic capacitor)
FIG. 10 is a LT plane cross-sectional view of an electrolytic capacitor according to another embodiment.
In the electrolytic capacitor 201 shown in FIG. 10, the mask layer 240 of the capacitor element 220 located furthest to the bottom among the capacitor elements 20 constituting the laminate 30 is thick.
Further, in the vicinity of the second surface 30b of the laminate 30, a cathode spacer 250 is provided below (on the bottom side) the capacitor element 220 located closest to the bottom side.
The cathode spacer 250 is preferably made of an insulating resin material.

By providing the mask layer 240 and the cathode side spacer 250 under the capacitor element 220 located at the bottom side (on the bottom side), the connection between the capacitor element 220 located at the bottom side and the bottom surface 1c of the electrolytic capacitor 201 is The distance between them becomes longer. In this way, the first lead frame 11 located on the bottom surface 1c of the electrolytic capacitor 201 and the conductive layer 7b of the capacitor element 220 located on the bottom side are prevented from coming into contact and causing a short circuit.

Further, by adopting the structure for preventing short circuits in this way, the length of the L-shaped short side of the first lead frame 11 can be increased, and the first lead frame 11 on the bottom surface 1c of the electrolytic capacitor 201 can be The area of the lead frame 11 can be made large enough for mounting. At the same time, since the conductive layer 7b of the capacitor element 20 can be provided as close to the first surface 30a of the laminate 30 as possible, the capacitance of the electrolytic capacitor can be increased.
The cathode side spacer 250 is provided to match the height with the anode side.

FIG. 11 is a LT plane cross-sectional view of an electrolytic capacitor according to another embodiment.
In the electrolytic capacitor 202 shown in FIG. 11, a cathode-side spacer 250 is provided near the second surface 30b of the laminate 30 for the capacitor element 220 located at the bottom side of the capacitor elements 20 constituting the laminate 30. is provided, and an anode side spacer 260 is provided near the first surface 30a of the laminate 30.
The cathode spacer 250 and the anode spacer 260 are preferably made of an insulating resin material.

Like the electrolytic capacitor 201 shown in FIG. This prevents the conductive layer 7b of the capacitor element 220 located closest to the bottom surface from coming into contact with each other and causing a short circuit. The same applies to other effects.

In the case of the electrolytic capacitor 202 shown in FIG. 11, it is possible to use a capacitor element 220 located at the bottom side with the same specifications (same mask layer specifications) as the other capacitor elements 20, so that the thickness of the mask layer This has an advantage over the electrolytic capacitor 201 shown in FIG. 10 in that there is no need to prepare a thick capacitor element.

FIG. 12 is a process diagram schematically showing a part of the manufacturing process of the electrolytic capacitor shown in FIG. 11.
FIG. 12 shows a series of lead frames for use in manufacturing three electrolytic capacitors. The first lead frame series 110 is on the right side, and the second lead frame series 120 is on the left side, and the lead frame series is similar to the lead frame series shown in FIG.
A spacer paste 270 is applied to the connecting portions 112 of the first lead frame series 110 and the connecting portions 122 of the second lead frame series 120 at positions where the laminate is to be placed. By placing the bottom surface of the laminate at the position where the spacer paste 270 is applied, the cathode spacer 250 and the anode spacer 260 can be provided.
The steps after placing the laminate can be the same as the steps described above to manufacture an electrolytic capacitor.

Furthermore, when manufacturing the electrolytic capacitor 201 shown in FIG. 10, the cathode side spacer 250 can be provided by applying the spacer paste 270 only to the connecting portion 122 of the second lead frame series 120. .
The composition of the spacer paste is preferably insulating and contains a resin material having adhesive properties.

1 Electrolytic capacitor 1a First end face 1b of electrolytic capacitor Second end face 1c of electrolytic capacitor Bottom face 1d of electrolytic capacitor Upper face 1e of electrolytic capacitor First side face 1f of electrolytic capacitor Second side face 4 of electrolytic capacitor Valve action metal base 4a Core portion 4b Porous part 5 Dielectric layer 7a Solid electrolyte layer 7b Conductive layer 7b1 Carbon layer 7b2 Metal layer 8 Sealing resin 9 Resin molded body 11 First lead frame 13 Second lead frame 20 Capacitor element 21 First conductive resin Part 23 Second conductive resin part 30 Laminated body 30a First surface 30b of the laminated body Second surface 31 of the laminated body Contact layer 40 Mask layer 110 First lead frame series 111 Plate-shaped portion 112 Connecting portion 113 Conductive paste 120 Second lead frame series 121 Plate part 122 Connecting part 123

Conductive paste

201, 202 Electrolytic capacitor 220 Capacitor element located at the bottom side 240 Mask layer of the capacitor element located at the bottom side 250 Cathode side spacer 260 Anode Side spacer 270 Spacer paste

Claims

A valve metal base having a core portion and a porous portion formed along the surface thereof, a dielectric layer formed on the porous portion, and a solid electrolyte layer formed on the dielectric layer. , a conductive layer formed on the solid electrolyte layer, and a laminate including a plurality of capacitor elements stacked and having a first surface;
a first conductive resin portion provided on the first surface of the laminate and to which the core portion of the capacitor element is connected;
An electrolytic capacitor comprising: a first lead frame connected to the core portion via the first conductive resin portion.
The first surface of the laminate is provided with a contact layer that is in direct contact with the core, and the core is connected to the first conductive resin part via the contact layer. Electrolytic capacitors listed.
The electrolytic capacitor according to claim 2, wherein the contact layer is an electrode layer containing at least one selected from the group consisting of Cu, Ni, Sn, Ag, Zn, and Au.
The electrolytic capacitor according to claim 2, wherein the contact layer is an electrode layer made of Cu.
The electrolysis method according to any one of claims 2 to 4, wherein the contact layer is thicker in a portion where the contact layer is formed in the core portion than in a portion where the contact layer is formed in the porous portion. capacitor.
The electrolytic capacitor according to any one of claims 1 to 5, wherein the first conductive resin portion to which the core portions of each of the plurality of capacitor elements are connected is integrated.
7. In a cross section of the electrolytic capacitor taken along the length direction and the thickness direction, the first lead frame has an L-shape in which the first end surface of the electrolytic capacitor is the long side. An electrolytic capacitor according to any of the above.
Any one of claims 1 to 7, wherein the periphery of the laminate is sealed with a sealing resin, forming a rectangular parallelepiped-shaped resin molded body whose outer surface is the surface of the sealing resin and the surface of the first lead frame. Electrolytic capacitor described in the above.
A second conductive resin part provided on the second surface of the laminate and to which the conductive layer of the capacitor element is connected; and a second lead frame connected to the second conductive resin part. An electrolytic capacitor according to any one of claims 1 to 7.
Rectangular parallelepiped resin molding in which the periphery of the laminate is sealed with a sealing resin, and the outer surface is the surface of the sealing resin, the surface of the first lead frame, and the surface of the second lead frame. The electrolytic capacitor according to claim 9, which constitutes a body.