JP6774745B2 - Solid electrolytic capacitors and their manufacturing methods - Google Patents

Description

The present invention relates to a terminal structure of a tantalum solid electrolytic capacitor.

Numerous attempts have been made to increase the capacity of solid electrolytic capacitors. That is, by changing the arrangement and size of components other than the porous body such as the anode terminal and the anode lead without changing the size of the solid electrolytic capacitor itself, the porous body directly contributes to the increase in capacitance. Various methods for increasing the volume have been proposed.

Patent Document 1 describes solid electrolysis including an anode terminal and a cathode terminal provided by plating layers on both sides of a molding portion covering a capacitor element so that the end of the anode wire and the end of the cathode extraction layer are exposed. Capacitors are listed.

Patent Document 2 describes a capacitor element on the surface of either or both of a synthetic resin sheet piece on which a capacitor element is mounted on the upper surface and a synthetic resin package body that seals the capacitor element on the upper surface of the sheet piece. The structure of a package-type solid electrolytic capacitor in which an anode-side electrode film conductive to the anode portion and a cathode-side terminal electrode film conducting to the cathode portion is described.

JP-A-2009-302499 Japanese Unexamined Patent Publication No. 2001-052961

In the solid electrolytic capacitor described in Patent Document 1, it is said that the cathode terminal and the anode terminal can be provided by plating on both side surfaces of the molding portion, so that the cathode terminal can be provided without another lead frame. It is extremely difficult to plate the anode wire, and even if it is realized, the reliability of the electrical connection is low and the manufacturing cost increases because the connection is made only within the cross-sectional area of the anode wire. There is a problem.

The structure of the package-type solid electrolytic capacitor described in Patent Document 2 is such that the sheet piece is sealed with a synthetic resin sheet piece or a synthetic resin package in order to reduce the size and weight. A terminal electrode film is provided, and it is difficult to apply it as it is to a packaged solid electrolytic capacitor.

An object of the present invention is to provide a solid electrolytic capacitor having high reliability of electrical connection, shortening working time and reducing cost.

In order to solve the above problems, in the solid electrolytic capacitor according to the present invention, a metal foil having a cross-sectional area larger than that of the anode lead is connected to the anode lead, and the cross section of the metal foil or the cross section of the valve acting metal and the anode lead is plated. By applying this to make an anode terminal, or by connecting a metal foil made of a material different from that of the anode lead to the anode lead, the reliability of the electrical connection is enhanced. Further, an oxide film having a predetermined thickness is formed on the surfaces of the anode lead and the valve acting metal to suppress an increase in leakage current. In addition, if a metal such as aluminum whose oxide film can be easily removed is used as the metal foil, the working time can be shortened and the cost can be reduced.

According to the present invention, a porous body obtained by sintering a valvening metal powder, an anode lead derived from the porous body, and the porous body so as to be electrically insulated from the anode lead. A capacitor element including a conductive polymer layer, a graphite layer, a silver paste layer, and a silver protrusion provided on the silver paste, which are sequentially laminated on the body, is coated with an exterior resin, and the surface of the exterior resin is coated. It is a solid electrolytic capacitor provided with an anode terminal and a cathode terminal, and a metal foil of a material different from that of the anode lead is connected to the anode lead, and at least a part of the metal foil is made of the exterior resin. Solid electrolysis characterized in that it is exposed and plated to form the anode terminal, and a part of the silver protruding portion is exposed from the exterior resin and plated to form the cathode terminal. A anode is obtained.

According to the present invention, a solid electrolytic capacitor can be obtained in which the area of the exposed portion of the metal foil from the exterior resin is larger than the area of the cross section in the direction orthogonal to the longitudinal direction of the anode lead.

According to the present invention, a porous body obtained by sintering a valvening metal powder, an anode lead derived from the porous body, and the porous body so as to be electrically insulated from the anode lead. A capacitor element including a conductive polymer layer, a graphite layer, a silver paste layer, and a silver protrusion provided on the silver paste, which are sequentially laminated on the body, is coated with an exterior resin, and the surface of the exterior resin is coated. It is a solid electrolytic capacitor provided with an anode terminal and a cathode terminal, and a metal foil is connected to the anode lead, and at least a part of the metal foil is exposed from the exterior resin and plated. The area of the exposed portion of the metal foil from the exterior resin is formed by forming the anode terminal, and a part of the silver protruding portion is exposed from the exterior resin and plated to form the cathode terminal. Is obtained, which is larger than the area of the cross section in the direction orthogonal to the longitudinal direction of the anode lead.

According to the present invention, the porous body obtained by sintering the valve acting metal powder, the anode lead derived from the porous body, and the porous body so as to be electrically insulated from the anode lead. A capacitor element including a conductive polymer layer, a graphite layer, a silver paste layer, and a silver protrusion provided on the silver paste, which are sequentially laminated on the body, is coated with an exterior resin, and the surface of the exterior resin is coated. It is a solid electrolytic capacitor provided with an anode terminal and a cathode terminal, and a metal foil is connected to the anode lead, and a part of the anode lead and a part of the metal foil are exposed from the exterior resin. Then, it is plated to be the anode terminal, a part of the silver protrusion is exposed from the exterior resin, and is plated to be the anode terminal, and the anode lead and the metal foil are formed. A solid electrolytic capacitor is obtained, wherein the total area of the exposed portion from the exterior resin is larger than the area of the cross section in the direction orthogonal to the longitudinal direction of the anode lead.

According to the present invention, a solid electrolytic capacitor is obtained in which an oxide film is applied to the surfaces of the anode lead and the (valve action) metal foil except for the contact portion with the plating.

According to the present invention, the metal foil is a solid electrolytic capacitor characterized by being a valve acting metal.

According to the present invention, the metal foil provides a solid electrolytic capacitor characterized by containing aluminum.

According to the present invention, a step of connecting a metal foil made of a material different from that of the anode lead to an anode lead derived from a porous body obtained by sintering a valve acting metal powder, and the anode lead and the valve. A step of forming an oxide film on the surface of the working metal foil, and a conductive polymer layer, a graphite layer, and a silver paste layer are sequentially formed on the surface of the porous body, and a silver protrusion portion is partially formed on the silver paste layer. A step of forming the capacitor element to obtain a capacitor element, a step of coating the capacitor element with an exterior resin, a step of exposing the metal foil and the silver protrusions from the exterior resin, and an exposed portion of the metal foil. A step of forming an anode terminal by plating a part of the surface of the exterior resin, and plating a part of the surface of the exterior resin so as to include an exposed portion of the silver protrusion to form an anode terminal. A method for manufacturing a solid electrolytic capacitor is obtained, which comprises a step of forming a cathode terminal so as to be electrically insulated.

According to the present invention, the area of the cross section of the anode lead derived from the porous body obtained by sintering the valve acting metal powder in the direction orthogonal to the longitudinal direction of the anode lead is larger than that of the anode lead. A step of connecting a metal foil having a large cross-sectional area in a direction orthogonal to the longitudinal direction, a step of forming an oxide film on the surface of the anode lead and the valve acting metal foil, and a step of high conductivity on the surface of the porous body. A step of sequentially forming a molecular layer, a graphite layer, and a silver paste layer and forming a silver protrusion on a part of the silver paste layer to obtain a capacitor element, a step of coating the capacitor element with an exterior resin, and the above-mentioned A step of exposing the metal foil and the silver protrusion from the exterior resin, a step of plating a part of the surface of the exterior resin so as to include the exposed portion of the metal foil to form an anode terminal, and the silver. Solid electrolysis comprising a step of plating a part of the surface of the exterior resin so as to include an exposed portion of a protrusion to form a cathode terminal so as to be electrically insulated from the anode terminal. A method for manufacturing a capacitor can be obtained.

As a result, it is possible to provide a solid electrolytic capacitor having high reliability of electrical connection, shortening working time and reducing cost.

It is sectional drawing of the solid electrolytic capacitor which concerns on 1st Embodiment of this invention. It is a partial explanatory view of the solid electrolytic capacitor which concerns on 1st Embodiment of this invention. It is sectional drawing of the solid electrolytic capacitor which concerns on 2nd Embodiment of this invention. It is a partial explanatory view of the solid electrolytic capacitor which concerns on 2nd Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail.

(First Embodiment)
FIG. 1 is a cross-sectional view of a solid electrolytic capacitor according to the first embodiment of the present invention.
FIG. 2 is a partial explanatory view of the solid electrolytic capacitor according to the first embodiment of the present invention.

Similarly, one end of the anode lead 1 made of tantalum is embedded in the porous body 2 obtained by sintering using tantalum powder as the valve acting metal, and the other end is derived. As illustrated in FIG. 2, a part of the front surface of the metal foil 3 using aluminum is connected to a part of the side peripheral surface of the anode lead 1 by welding.

Tantalum has a high ability to form an oxide film and forms a strong oxide film. Therefore, when tantalum is used as the anode lead, it is necessary to perform plating after removing the oxide film formed on the cross section of the anode lead, but it is difficult to remove the oxide film. Therefore, in general, substitution plating is formed with a palladium catalyst, and then an anode terminal is formed by electroless plating or electrolytic plating, but the use of palladium increases the manufacturing cost.

In the present embodiment, paying attention to this point, manufacturing man-hours and costs are reduced by using an aluminum metal foil that is easier to plate than tantalum, that is, has a lower acid resistance of the oxide film and does not require the use of a palladium catalyst. To do.

Further, in order to further improve the reliability of the electrical connection, the direction in which the anode lead 1 is derived, that is, the direction orthogonal to the longitudinal direction of the anode lead 1 rather than the area of the cross section of the anode lead 1 in the direction orthogonal to the longitudinal direction. The area and thickness of the front surface of the metal foil 3 are appropriately adjusted so that the cross-sectional area of the metal foil 3 is large.

Either connecting metal foils of different materials or using a metal foil having a larger area than the cross-sectional area of the anode reed is effective, but it is more preferable to use both at the same time.

It is also possible to increase the area for plating by exposing both a part of the anode reed and a part of the valve working metal connected to the anode reed from the exterior resin layer in order to improve the reliability of the electrical connection. preferable.

The area, thickness, and shape of the front surface of the metal foil 3 may be any as long as the above conditions are satisfied and the shape does not come into contact with the porous body 2 when the capacitor element is molded with the exterior resin. The metal foil 3 also includes a plate-shaped or columnar metal piece.

Further, when tantalum is adopted as the anode lead 1 as in the present embodiment, or when niobium or an alloy thereof is adopted, a chemical or the like containing a relatively expensive material such as palladium is used before plating formation. The existing pretreatment process is required. However, when aluminum or an alloy containing aluminum is used as the metal foil 3, the pretreatment step can be simplified.

Therefore, if the total area of the plating forming portion is made larger than the cross section of the anode lead, the metal foil 3 may use the same material as the anode lead 1, but it is relatively easy to weld the anode lead 1 to the metal foil 1. It is preferable to select a material that can be connected to and is easier to form plating. That is, as the metal foil, it is preferable to appropriately select and use a metal having a valve action such as tantalum, niobium, aluminum or an alloy containing these, or copper or a copper alloy, etc., but as the anode lead, tantalum, niobium or When these alloys are adopted, it is more preferable to use aluminum or an alloy containing aluminum as the metal foil.

Further, an oxide film 4 is formed on the surfaces of the anode lead 1 and the metal foil 3 by a known means. That is, for example, a voltage higher than the rated voltage of the solid electrolytic capacitor, which is the final product, is applied in the phosphoric acid aqueous solution to form an oxide film 4 having a rated voltage of 1.3 nm or more per 1 V.

A conductive polymer layer 5, a graphite layer 6, and a silver paste layer 7 are sequentially formed on the surface of the porous body 2 as a cathode layer. When the method of immersing the porous body 2 in the polymer solution or suspension of the conductive polymer is adopted when forming the conductive polymer layer 5, a part of the conductive polymer layer 5 is formed. It crawls up to the anode lead 1 and the aluminum metal foil 3, and the oxide film 4 and the conductive polymer layer 5 overlap each other at the lead-out portion of the anode lead 1.

With this configuration, the generation of leakage current is suppressed, so that the metal foil 3 can be arranged close to the porous body 2 to some extent. Therefore, the volume of the porous body 3 can be made larger than before without changing the size of the entire capacitor element.

Subsequently, a convex silver protrusion 8 is provided on the surface of the porous body 2 facing the surface from which the anode lead 1 is derived, using the same silver paste as the silver paste layer 7, to form a capacitor element.

The capacitor element is molded by, for example, an exterior resin layer 9 made of an epoxy resin and a filler, and then cut by dicing, for example, so as to have a desired product shape, and the cross section of the metal foil 3 and the silver protrusion 8 is exteriorized. It is exposed from the resin layer 9.

Subsequently, the cross section of the metal foil 3 exposed from the exterior resin layer 9 is surface-treated by a known means to form a plating forming portion. That is, for example, the cross section of the metal foil 3 is immersed in a strong acid to remove the oxide film 4 on the surface, and then the cross section of the metal foil 3 is further treated with, for example, a zinc catalyst.

After the surface treatment is completed, for example, electroless plating is applied, and further, the surface of the exterior resin layer 9 including the cross section of the metal foil 3 is sequentially subjected to, for example, a palladium catalyst or electroless plating by a known means. , The anode terminal 10 is formed.

Similarly, the surface of the exterior resin layer 9 including the cross section of the silver protrusion 8 exposed from the exterior resin layer 9 is also subjected to a known means, that is, for example, a palladium catalyst or electroless plating is sequentially applied to the cathode. The terminal 11 is formed to obtain a solid electrolytic capacitor.

A part of the anode terminal 10 and the cathode terminal 11 is arranged in the same plane in order to be an electrode terminal for solder mounting, for example, but these are electrically insulated by the exterior resin layer 9. There is.

As described above, by connecting a metal foil to the anode lead to obtain a plating forming surface larger than the area of the cross section in the direction orthogonal to the longitudinal direction of the anode lead, an anode terminal having a more stable electrical connection is formed. It is possible to obtain a solid electrolytic capacitor with reduced ESR.

However, although tantalum, which easily forms an oxide film, is suitable as an anode lead material, man-hours are required to remove the oxide film when plating. Cost and manufacture by connecting a metal foil made of a material that is relatively easy to form a plating, that is, a metal foil made of a material that has an easy pretreatment step for plating or a small number of steps, and using the cross section as a plating forming surface. It is possible to reduce the number of steps.

(Second Embodiment)
FIG. 3 is a cross-sectional view of the solid electrolytic capacitor according to the second embodiment of the present invention.
FIG. 4 is a partial explanatory view of the solid electrolytic capacitor according to the second embodiment of the present invention.

A solid electrolytic capacitor is obtained by the same materials and methods as in the first embodiment.

In the present embodiment, as illustrated in FIG. 4, a part of the front surface of the metal foil 3 is connected by welding to a cross section in a direction orthogonal to the longitudinal direction of the anode lead 1. At this time, the area of the front surface of the metal foil 3 is so that the area of the front surface of the metal foil 3 is larger than the area of the cross section of the anode lead 1 in the direction orthogonal to the longitudinal direction of the anode lead 1. Is adjusted as appropriate.

Compared to the first embodiment, since the metal foil 3 is more exposed from the exterior resin layer 9, the reliability of the electrical connection with the anode terminal is increased.

According to various experiments, the exposed area of the metal foil from the exterior resin is preferably twice or more, more preferably 10 times or more, the cross-sectional area of the anode lead.

Hereinafter, examples of the present invention will be specifically described.

(Example 1)
Tantalum powder is sintered on an anode lead 1 made of columnar tantalum having a diameter of 0.2 mm to form a porous body 2, and the thickness is 0 on the anode lead 1 at a distance of 0.05 mm from the porous body 2. An aluminum metal foil 3 having a width of .2 mm and a width of 0.16 mm and having substantially the same cross-sectional area as the anode lead 1 was welded.

Subsequently, a voltage of 20 V was applied to the surfaces of the anode lead 1, the porous body 2 and the metal foil 3 in an aqueous phosphoric acid solution to form an oxide film 4 having a diameter of 26 nm or more on the surfaces.

Next, the conductive polymer layer 5 is filled inside the pores of the porous body 2 with a polymerization solution composed of ethylenedioxythiophene and ferric toluenesulfonic acid, and further, the outer surface of the porous body 2 is about. The conductive polymer layer 5 was formed so as to have a thickness of 5 μm. Due to the surface tension of the polymer solution, a part of the conductive polymer layer 5 crawls up to the metal foil 3 via the anode lead 1.

After the graphite layer 6 and the silver paste layer 7 are sequentially formed on the conductive polymer layer 5 excluding the embedded surface of the anode lead 1 of the porous body 2, the facing surface of the embedded surface of the anode lead 1 of the porous body 2 is formed. On the silver paste layer 7 of the above, a convex silver protrusion 8 was formed with the same type of silver paste as the silver paste layer 7 at a height of 0.2 mm to form a condenser element.

The exterior resin layer 9 is formed to have a thickness of 1 mm by injection molding using a resin composed of an epoxy resin and a filler so as to cover all of the anode lead 1, the porous body 2, the metal foil 3, and the silver protrusion 8. did.

The exterior resin layer 9 is cut by dicing so as to have a shape of 2.0 mm in the length direction and 1.2 mm in the width direction, and the metal foil 3 and the silver protrusion 8 are respectively formed on the cut surface obtained by dicing. Exposed.

Next, the exposed portion of the metal foil 3 is immersed in 10 wt% sulfuric acid to remove the oxide film 4, and the cross section of the metal foil 3 is immersed in a zinc catalyst, followed by electroless copper plating, electroless nickel plating, and electroless electrolysis. Tin plating was sequentially formed and plated so that the total thickness was 0.1 mm or less.

Further, a palladium catalyst, electroless copper plating, electroless nickel plating, and electroless tin plating are applied to the exterior resin layer 9 on the same surface as the metal foil 3 including the exposed portion of the metal foil 3 and the mounting surface of the exterior resin layer 9. They were sequentially formed and plated with a total thickness of 0.1 mm or less to form an anode terminal.

Further, the exterior resin layer 9 on the same surface as the silver protrusion 8 including the exposed portion of the silver protrusion 8 and the mounting surface of the exterior resin layer 9 are surfaced with a palladium catalyst, electroless copper plating, electroless nickel plating, and electroless tin. A solid electrolytic capacitor was obtained in which plating was sequentially formed and plating having a total thickness of 0.1 mm or less was performed to form a cathode terminal, and the anode terminal 10 and the cathode terminal 11 were used as electrode terminals for solder mounting.

Here, on the mounting surface, the intermediate portion between the anode terminal 10 and the cathode terminal 11 is previously divided by a masking process and electrically insulated.

Compared with the case where the solid electrolytic capacitor according to this example is plated on the anode lead of tantalum, the metal foil of aluminum is plated, so that there is a danger of hydrofluoric acid or the like as a treatment agent before plating. Since it is not necessary to use various chemicals and the oxide film can be removed in a short time, the work time for plating has been reduced by about 20%.

Similarly, by substituting a part of the palladium catalyst used as a treatment agent before plating with a zinc catalyst, the amount of palladium used could be reduced and the material cost of plating could be reduced by 10%.

(Example 2)
As the metal foil 3, the same material as in the examples and the same materials as in the examples except that the area of the exposed portion from the exterior resin layer 9 is twice the area of the cross section in the direction orthogonal to the longitudinal direction of the anode lead 1 are used. A solid electrolytic capacitor was made by the method.

Similar to the first embodiment, not only the working time for plating and the material cost of plating can be significantly reduced, but also the reliability of the electrical connection is improved by the stable connection with the anode terminal.

That is, the solid electrolytic capacitor of this embodiment is electrically charged because the aluminum metal foil 3 having twice the cross-sectional area is plated as compared with the case where the cross section of the tantalum anode lead is plated. The reliability of the connection is greatly improved, and in the temperature cycle test from -55 ° C to 105 ° C, the solid electrolytic capacitor of the conventional example having the same configuration as this example except that no metal foil is used has 100 cycles. However, the solid electrolytic capacitor of this example was within the standard even after 1000 cycles.

Further, since the connection resistance between the anode and the plated portion is significantly reduced, the ESR of the solid electrolytic capacitor of the above-mentioned conventional example is 80 mΩ on average, whereas the ESR of the solid electrolytic capacitor of this example is 60 mΩ on average. Met.

(Example 3)
Tantal powder is sintered on the anode lead 1 of a columnar tantalum having a diameter of 0.2 mm to form a porous body 2, and the thickness is 0.3 mm on the anode lead 1 0.05 mm away from the porous body 2. A tantalum metal foil 3 having a width of 1.2 mm and a cross-sectional area 10 times or more that of the anode lead 1 is welded to the surface of the anode lead 1, the porous body 2, and the metal foil at 20 V in an aqueous phosphate solution. A voltage is applied to form an oxide film 4 on the surface so as to have an anode of 26 nm or more, and in the same process as in Example 1, cutting is performed by dying to obtain cross sections of the metal foil 3 and the silver protrusion 8. It was exposed from the exterior resin layer 9.

Next, the cross section of the metal foil 3 is immersed in 10 wt% sulfuric acid to remove the oxide film 4, and the cross section of the metal foil 3 is immersed in a zinc catalyst, followed by electroless copper plating, electroless nickel plating, and electroless tin. Plating was sequentially formed, and plating was performed so that the total thickness of the plating was 0.1 mm or less.

Further, a palladium catalyst, electroless copper plating, electroless nickel plating, and electroless tin plating are applied to the exterior resin layer 9 on the same surface as the metal foil 3 including the exposed portion of the metal foil 3 and the mounting surface of the exterior resin layer 9. They were sequentially formed and plated with a total thickness of 0.1 mm or less to form an anode terminal.

Further, the exterior resin layer 9 on the same surface as the silver protrusion 8 including the exposed portion of the silver protrusion 8 and the mounting surface of the exterior resin layer 9 are surfaced with a palladium catalyst, electroless copper plating, electroless nickel plating, and electroless tin. A solid electrolytic capacitor was obtained in which plating was sequentially formed and plating having a total thickness of 0.1 mm or less was performed to form a cathode terminal, and the anode terminal 10 and the cathode terminal 11 were used as electrode terminals for solder mounting.

Here, on the mounting surface, the intermediate portion between the anode terminal 10 and the cathode terminal 11 is previously divided by a masking process and electrically insulated.

Since the solid electrolytic capacitor of this embodiment is plated on the metal leaf 3 of tantalum having a cross-sectional area 10 times or more that of the case where plating is formed on the cross section of the anode lead of tantalum, it is electrically connected. The reliability is greatly improved, and in the temperature cycle test from -55 ° C to 105 ° C, the solid electrolytic capacitor of the above-mentioned conventional example becomes out of specification in 100 cycles, whereas the solid electrolytic capacitor of this example is 1000. It was within the standard even in the cycle.

Further, since the connection resistance between the anode and the plated portion is significantly reduced, the ESR of the solid electrolytic capacitor of the above-mentioned conventional example is 100 mΩ on average, whereas the ESR of the solid electrolytic capacitor of this example is 60 mΩ on average. Met.

As described in detail, a metal foil having a cross section larger than that of the anode lead is connected to the anode lead, and the cross section of the metal foil is plated to obtain a solid electrolytic capacitor with improved reliability of electrical connection. Was done.

Furthermore, by connecting a metal foil, which is relatively easy to form plating, to the anode reed, unlike the anode reed, which requires man-hours for plating formation, a solid electrolytic capacitor that shortens the work time and realizes cost reduction was obtained. ..

In addition, a solid electrolytic capacitor in which an increase in leakage current was suppressed was obtained by forming an oxide film having a predetermined thickness on the surfaces of the anode lead and the valve acting metal.

Although the examples of the present invention have been described above, the present invention is not limited to the above, and the configuration can be changed or modified without departing from the gist of the present invention. That is, various modifications and modifications that can be made by those skilled in the art are also included in the present invention.

1 Anode lead 2 Porous body 3 Metal foil 4 Oxide film 5 Conductive polymer layer 6 Graphite layer 7 Silver paste layer 8 Silver protrusion 9 Exterior resin layer 10 Anode terminal 11 Cathode terminal

Claims (5)

A porous body obtained by sintering a valve-acting metal powder, an anode lead derived from the porous body, and sequentially laminated on the porous body so as to be electrically insulated from the anode lead. A capacitor element including a conductive polymer layer, a graphite layer, a silver paste layer, and a silver protrusion provided on the silver paste is coated with an exterior resin, and an anode terminal and a cathode terminal are provided on the surface of the exterior resin. It is a solid electrolytic capacitor provided with
The anode leads consist of tantalum, niobium or alloys of these.
A metal foil containing aluminum is connected to the anode reed.
Of the two surfaces of the metal foil orthogonal to the longitudinal direction of the capacitor element, one surface is connected to the anode lead, and the entire surface of the other surface not connected to the anode lead is exposed from the exterior resin. It is plated and used as the anode terminal.
A solid electrolytic capacitor characterized in that a part of the silver protruding portion is exposed from the exterior resin and plated to serve as the cathode terminal. The claim is characterized in that the area of the exposed portion, which is the other surface of the metal foil exposed from the exterior resin , is larger than the area of the cross section of the anode lead in the direction orthogonal to the longitudinal direction of the anode lead. 1. The solid electrolytic capacitor according to 1. The solid electrolytic capacitor according to claim 1 or 2, wherein an oxide film is applied to the surfaces of the anode lead and the metal foil except for the contact portion with the plating. A step of connecting a metal foil containing aluminum to an anode lead derived from a porous body obtained by sintering a metal powder of tantalum, niobium, or an alloy thereof, and
A step of forming an oxide film on the surfaces of the anode lead and the metal foil, and
A step of sequentially forming a conductive polymer layer, a graphite layer, and a silver paste layer on the surface of the porous body, and forming a silver protrusion on a part of the silver paste layer to obtain a capacitor element.
The process of coating the capacitor element with exterior resin and
The metal foil, one of the two surfaces perpendicular to the longitudinal direction of the capacitor element, in the state where one surface is connected to the anode lead, the entire surface of the other surface of the metal foil is not connected to the anode lead The process of removing the oxide film and exposing it from the exterior resin,
The step of exposing the silver protrusion from the exterior resin and
A step of forming an anode terminal by plating a part of the surface of the exterior resin so as to include an exposed portion which is the other surface of the metal foil.
It is characterized by including a step of plating a part of the surface of the exterior resin so as to include an exposed portion of the silver protrusion to form a cathode terminal so as to be electrically insulated from the anode terminal. A method for manufacturing a solid electrolytic capacitor. A step of connecting the metal foil to the anode lead, which has a larger cross-sectional area in the direction orthogonal to the longitudinal direction of the anode lead than the cross-sectional area of the anode lead in the direction orthogonal to the longitudinal direction of the anode lead. The method for manufacturing a solid electrolytic capacitor according to claim 4, wherein the solid electrolytic capacitor is included.

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