JP5007678B2 - Solid electrolytic capacitor and manufacturing method thereof - Google Patents

Description

  The present invention relates to a multi-terminal solid electrolytic capacitor that is thin and has a high degree of freedom in component arrangement, and has excellent manufacturing accuracy and efficiency in addition to characteristics, and a manufacturing method thereof.

At present, various capacitors are used in various electronic circuit fields, and as one of them, solid electrolytic capacitors having a small equivalent series resistance (ESR) and excellent frequency characteristics are widely used. Patent Documents 1 and 2 show an example of a conventional solid electrolytic capacitor and a manufacturing method thereof. In this example, a solid electrolyte layer or the like is provided in a recess provided in a metal plate serving as an anode body and is cut into individual pieces. Two cathode bodies are sandwiched and an anode terminal is attached.
JP-A-3-284818 JP-A-4-5813 JP-A-2-301118

  However, in recent years, in the field of digital equipment such as personal computers, multi-terminal type solid electrolytic capacitors have been demanded from the viewpoint of improving characteristics such as low ESL (equivalent series inductance), and the equipment has been adapted to downsizing and high speed operation. Combined with the demand for excellent transient response, there is a need for a solid electrolytic capacitor that is thinner and has a high degree of freedom in component placement. Furthermore, there is a great demand for further improvement in production efficiency from the viewpoint of meeting increasing demand and costs.

  In this regard, the conventional solid electrolytic capacitor as described above has a structure in which a cathode body is sandwiched between two pieces and an anode terminal is attached, and there is a limit to improvement in manufacturing efficiency and reduction in size. Also, in the conventional solid electrolytic capacitor as described above, due to size and shape restrictions, it is essential to mount it on the board at a position shifted in the horizontal direction from the LSI that is the current supply target. There is a limit to the improvement, and from this point, an increase in the degree of freedom in component arrangement has been desired.

  In addition, in a method of manufacturing a solid electrolytic capacitor in which a flat solid electrolyte layer or an insulating layer having openings is laminated on a substrate to draw out each electrode, the substrate is divided into comb-like rows and columns by cutting. Although there are proposals to improve the manufacturing efficiency (for example, refer to Patent Document 3, especially FIG. 1 (B)), the substrate in which only one end is connected is unstable and the accuracy and efficiency of processing are limited. .

  The present invention solves the above-described conventional problems, and its purpose is a multi-terminal solid that is thin and small, has a high degree of freedom in component placement, and has excellent manufacturing accuracy and efficiency in addition to characteristics. An electrolytic capacitor and a manufacturing method thereof are provided.

  In order to achieve the above object, a solid electrolytic capacitor according to an aspect of the present invention is formed by forming a reinforcing layer on one surface of a metal plate made of a valve metal and forming a protective layer on the opposite surface, and cutting the surface of the protective layer. By forming a plurality of groove-shaped holes that penetrate the metal plate but do not penetrate the reinforcing layer, a metal plating process is applied to at least the inner surface of the hole, and a predetermined surface is formed on the surface of the metal plate between the adjacent holes. By exposing the ingot of the metal plate forming the anode part on the inner surface of the recess by forming recesses at intervals, the ingot of the inner surface of the recess is expanded, and an oxide film layer is formed on the surface, A solid electrolyte layer is formed on the oxide film layer in the recess, a cathode terminal is formed on the solid electrolyte layer, and the metal plate and the reinforcing layer are cut at the groove-shaped hole portion. Thus, a solid electrolytic capacitor can be obtained. The features.

  Another aspect of the present invention is a method for manufacturing a solid electrolytic capacitor, taking the above aspect from the viewpoint of a method, the step of forming a reinforcing layer on one surface of a metal plate made of a valve metal and a protective layer on the opposite surface; A step of forming a plurality of groove-shaped holes penetrating the metal plate by cutting from the surface of the protective layer but not the reinforcing layer; and a step of performing metal plating on at least an inner surface of the hole; A step of exposing the metal plate of the metal plate to form an anode part on the inner surface of the recess by forming recesses at predetermined intervals on the surface of the metal plate between the adjacent holes; A step of forming an oxide film layer on the surface, a step of forming a solid electrolyte layer on the oxide film layer in the recess, and a cathode terminal portion on the solid electrolyte layer And the groove-shaped hole portion In by cutting the metal plate and the reinforcing layer, characterized by comprising the steps of a solid electrolytic capacitor of the pieces, the.

  In this way, by providing an oxide film layer, a solid electrolyte layer, and a cathode terminal in the concave portion on one side of the metal plate, by performing metal plating on the inner surface of the groove-shaped hole formed in the metal plate, and cutting at the position of the hole The metal plating on the inner surface of the hole is exposed to the outside of both ends of the solid electrolytic capacitor, and becomes the external electrode of the anode as it is. As described above, since the anode external electrode is directly formed on the metal plate serving as the anode part of the solid electrolytic capacitor, the area of the anode terminal part that does not contribute to the capacitance of the solid electrolytic capacitor may be extremely small. it can. Further, the metal plate that forms the anode portion on the inner surface as a concave portion on one side of the metal plate provided with the protective layer is exposed, and an oxide film layer, a solid electrolyte layer, and a cathode terminal are provided, thereby providing a capacitor. The cathode terminal part is formed in the vicinity of the interface between the oxide film and the solid electrolyte layer, which is a capacitor holding part, and the distance to the circuit pattern or LSI device connected to the capacitor holding part and the cathode terminal part is short. Since the current routing path inside the capacitor is shortened, the transient response to the unstable power supply voltage is improved. In particular, by adding a reinforcing layer to the metal plate and forming a hole that penetrates the metal plate but does not penetrate the reinforcing layer, the metal plate is processed stably with the reinforcing layer compared to the case of cutting in a comb-like shape as in the past. Accuracy and efficiency can be maintained.

  Another aspect of the present invention is characterized in that in the solid electrolytic capacitor, a portion of the cathode terminal portion excluding a predetermined external exposed portion to be exposed to the outside is covered with an insulating resin.

  Another aspect of the present invention is to capture the above aspect from the viewpoint of a method. In the method for manufacturing the solid electrolytic capacitor, a portion of the cathode terminal portion excluding a predetermined external exposed portion to be exposed to the outside. And a step of coating with an insulating resin.

  Thus, by covering the periphery of the cathode terminal portion with the insulating resin, the resin enters the gap between the cathode external electrode and the concave portion to improve the insulation between the anode and the cathode, and the cathode external portion constituting the cathode terminal portion. By covering a part of the electrode, the bonding strength of the cathode external electrode can be increased.

  According to another aspect of the present invention, in any one of the solid electrolytic capacitors, after the hole that has been cut is further closed with a sealing member, the surface enlargement process and the subsequent steps are performed, and the solid electrolytic process is performed individually. The sealing member is removed before the cutting into the capacitor.

  Another aspect of the present invention is to capture the above aspect from the viewpoint of a method. In any one of the above-described solid electrolytic capacitor manufacturing methods, the cut hole is closed with a sealing member before the surface expansion treatment. And a step of removing the sealing member before the cutting of the individual pieces into the solid electrolytic capacitor.

  Thus, by closing the hole that has been cut with the sealing member before the surface expansion treatment, the metal plating can be reliably used as an anode terminal without being dissolved during etching for the surface expansion treatment. By removing before cutting into individual pieces, the cutting process becomes smooth and highly accurate, and the adhesion of impurities to the individual pieces of products can be suppressed to a minimum.

  A solid electrolytic capacitor according to another aspect of the present invention is formed by forming a reinforcing layer on one surface of a metal plate made of a valve metal and a protective layer on the opposite surface, and cutting the metal plate from the surface of the protective layer. Forming a plurality of groove-shaped holes that penetrate but do not penetrate the reinforcing layer, fill the inside of the holes with a conductive material, and form recesses at predetermined intervals on the surface of the metal plate between the adjacent holes. The metal plate forming the anode part on the inner surface of the recess is exposed by the above, the valve metal metal on the inner surface of the recess is expanded, an oxide film layer is formed on the surface, Forming a solid electrolyte layer on the oxide film layer, forming a cathode terminal portion on the solid electrolyte layer, and filling the conductive material and the metal plate at the groove-shaped hole portion And by cutting the reinforcing layer, individual solid electrolytic capacitors Characterized in that it was.

  Another aspect of the present invention is a method for manufacturing a solid electrolytic capacitor, taking the above aspect from the viewpoint of a method, the step of forming a reinforcing layer on one surface of a metal plate made of a valve metal and a protective layer on the opposite surface; A step of forming a plurality of groove-shaped holes that penetrate the metal plate by cutting from the surface of the protective layer but do not penetrate the reinforcing layer; and a step of filling the inside of the hole with a conductive material; A step of exposing a metal bar of the metal plate to form an anode part on the inner surface of the concave part by forming concave parts at predetermined intervals on the metal plate surface between the adjacent holes; A step of expanding the surface to form an oxide film layer on the surface, a step of forming a solid electrolyte layer on the oxide film layer in the recess, and a cathode terminal portion on the solid electrolyte layer Filling the process and the groove-shaped hole part By in said conductive material and cutting said metal plate and said reinforcement layer, characterized by comprising the steps of a solid electrolytic capacitor of the pieces, the.

  As described above, the oxide film layer, the solid electrolyte layer, and the cathode terminal are provided in the concave portion on one side of the metal plate, and the conductive material filled in the groove-like hole formed in the metal plate is separated into pieces by separating the holes at the positions of the holes. It is exposed to the outside of both ends of the solid electrolytic capacitor and becomes the external electrode of the anode as it is. The thus obtained multi-terminal type solid electrolytic capacitor has an anode terminal that does not contribute to the capacitance of the solid electrolytic capacitor because the external electrode of the anode is formed directly on the metal plate that becomes the anode part of the solid electrolytic capacitor. The area of the part can be made extremely small. Moreover, the concave portion is exposed on one side of the metal plate provided with the protective layer, and the oxide film layer, the solid electrolyte layer, and the cathode terminal are provided, so that the interface between the dielectric oxide film and the solid electrolyte layer, which is a capacity holding portion as a capacitor, Is a structure in which the cathode terminal part is formed in the vicinity of the circuit pattern, the distance to the device such as the circuit pattern and LSI connected to the capacitor holding part and the cathode terminal part is short, and the current routing path inside the capacitor is shortened. Transient response to power supply voltage instability is improved. In addition, since the reinforcing layer is a hole that does not penetrate, the metal plate is more stable than before and processing accuracy and efficiency can be maintained. In addition, the entire inside of the hole is filled with copper, so that the inner surface of the hole is plated rather than plated. This eliminates the need for a protective resin, which simplifies the process and improves production efficiency and cost.

  As described above, according to the present invention, it is possible to provide a multi-terminal solid electrolytic capacitor that is thin and small, has a high degree of freedom in component placement, and has excellent manufacturing accuracy and efficiency in addition to characteristics, and a manufacturing method thereof. It becomes possible.

Next, the best mode for carrying out the present invention will be described with reference to the drawings. In addition, the premise common to the content already demonstrated by the background art and the subject is abbreviate | omitted suitably.
(1) Configuration The present embodiment relates to a method for manufacturing a solid electrolytic capacitor by the following processes A to J, and a solid electrolytic capacitor manufactured as such. Here, each process step is shown in the cross-sectional views of FIGS. 1 and 2, and a part of the process is shown in the perspective view of FIG.

A. Preparation of Metal Plate First, a metal plate 1 made of a valve metal, that is, a valve action metal is prepared (FIG. 1 (1)). This metal plate is long as shown in the perspective view of FIG. 3, and FIG.1 and FIG.2 is sectional drawing whose depth direction becomes a longitudinal direction toward the figure. The metal plate 1 is preferably made of aluminum and generally has a thickness of about 200 to 800 microns, but the type and thickness of the metal can be changed as appropriate. For example, valve action metals such as tantalum, niobium, and titanium can be used in addition to aluminum.

B. Formation of Reinforcing Layer and Protective Layer A reinforcing layer 2 (FIG. 1 (2)) is formed on one surface of the metal plate 1, and a protective layer 3 is formed on the opposite surface (FIG. 1 (3)). The reinforcing layer 2 can be selected freely by attaching a reinforcing member, that is, an insulating resin material such as an epoxy material, or by applying an insulating resin or a SUS material. It is preferable to use an insulating resin from the viewpoint of ensuring the above.

  In addition, the protective layer 3 does not need to cover the whole surface of the metal plate 1, and the window part for subsequent processing may be formed. Further, as the protective layer 3, in addition to a resin coating layer such as a so-called resist, an anodized film may be formed. If the layer is not corroded by the etching solution during the surface expansion treatment by etching described later, The formation method and the like can be freely selected.

C. Formation of hole Subsequently, the metal plate 1 is cut from the surface of the protective layer 3 to form a groove-like hole 4 that penetrates the metal plate 1 but does not penetrate the reinforcing layer 3 (FIG. 1 (4)). . Since this hole 4 is a part which makes an inner surface metal plating process, such as copper, and serves as an anode terminal in the both ends of the solid electrolytic capacitor piece which is a final product, as a shape of the hole 4, the perspective view of FIG. As shown in FIG. 3 (1)), it may be a continuous groove shape, or may be a plurality of holes intermittent at a constant pitch (length and interval). In any case, the reinforcing layer 3 is not connected in a comb-teeth shape, as viewed from the longitudinal direction of the groove-shaped hole, at least a part near both ends.

D. Metal Plating Treatment and Closure of Holes At least the inner surface of the hole 4 thus configured is subjected to metal plating treatment such as copper to form a metal plating surface 5 (FIG. 1 (5)). Further, the groove-shaped hole 4 subjected to the metal plating process is closed with a sealing member P such as a film tape made of an insulating resin (FIG. 1 (5)). When cutting a hole, the protective layer is removed to a certain extent around the hole to expose the metal plate, and the metal plating process is performed not only on the inner surface of the hole but also on the surface of the metal plate exposed on the periphery. FIG. 3 shows such an example.

E. Formation of Recesses Subsequently, by forming recesses 6 at predetermined intervals on the surface of the metal plate between the holes 4, the metal plate forming the anode part is exposed on the inner surface of the recess 6 (FIG. 1 (6 ), FIG. 3 (2)). Here, as a means for forming the recess 6, cutting of the metal plate 1 is suitable. When the protective layer 3 has a window portion, the window portion may be pressed to form a recess, or the window portion may be etched to form the recess 6. When the recess 6 is formed by the above, the recess can be efficiently formed by simultaneously performing the etching process of “F. Etching and formation of oxide film” described later.

F. Etching and Formation of Oxide Film Thereafter, the bare metal exposed on the inner surface of the recess 6 is subjected to a surface expansion process by etching, and further anodized on the surface of the recess subjected to the surface expansion process to form an oxide film layer 7 (FIG. 2). (7)). Here, well-known means can be used for etching and anodic oxidation.

G. Formation of Solid Electrolyte Layer A solid electrolyte layer 8 is formed on the oxide film layer 7 (FIG. 2 (8)). Here, as the solid electrolyte layer 8, a conductive polymer is suitable, and such a conductive polymer layer is formed by a known technique such as chemical polymerization or electrolytic polymerization based on thiophene, pyrrole, or the like. do it.

H. Formation of the cathode terminal portion And, by providing a cathode external electrode on the solid electrolyte layer 8 through a graphite (Gr) layer and a silver paste layer (indicated by reference numeral 9 together) (FIG. 2 (9)), The cathode terminal portion 10 is formed (FIG. 2 (10)). The graphite (Gr) layer and the silver paste layer itself may be the same as a known technique in a solid electrolytic capacitor.

  Moreover, as a cathode external electrode, it is suitable to connect metal board | plate materials, such as copper, with a conductive adhesive, However, A flat plate may be sufficient as a board | plate material. Moreover, you may use the cathode external electrode which has a processus | protrusion on a flat plate, In that case, the processus | protrusion part becomes a cathode external terminal. Further, the cathode external electrode may be configured by performing copper plating on the silver paste layer. However, a distance for insulation, that is, a gap is provided between the cathode external electrode which is the cathode terminal portion 10 and the protective layer 3.

  When a plate material having a plurality of protrusions formed on a flat plate is used as a cathode external electrode, and the plurality of protrusions are used as cathode external terminals, the cathode terminal portion 10 is a multi-terminal electrode structure derived as a plurality of cathode terminal portions 10. It becomes.

  It should be noted that a flat plate material may be used as the cathode external electrode, and the protrusions may be formed after the flat plate material is bonded to the silver paste layer. This protrusion is formed by using a so-called bump electrode, a gold bump obtained by cutting a gold wire by thermocompression bonding, and a ball grid array in which solder balls are bonded on a copper plating to form ball-shaped terminals in a grid array ( BGA) and the like can be freely selected.

I. Next, a portion of the cathode terminal portion 10 excluding a predetermined external exposed portion to be exposed to the outside is covered by injecting the insulating resin 11 around the gap or the like (FIG. 2 ( 11)). Here, the externally exposed portion is, for example, the upper surface or the protruding portion of the cathode terminal portion 10, and the portion excluding the externally exposed portion is, for example, the side end surface or the gap between the protective layer 3 and the like. Moreover, as the insulating resin 11, a thermosetting epoxy resin is suitable.

  The insulating resin 11 enters the gap between the concave portion and the cathode external electrode, so that the insulation between the anode and the cathode can be enhanced, and by covering a part of the cathode external electrode, the bonding strength of the cathode external electrode can be increased. Can be increased. For example, if a plate material having a plurality of protrusions formed on a flat plate is used as the cathode external electrode and the upper surface of the plate material is covered with the insulating resin 11 so that only the protrusions are exposed, the upper surface of the cathode external electrode is integrated with the metal plate. Thus, the bonding strength of the cathode external terminal can be increased.

J. et al. Cutting into pieces Finally, the sealing member P such as a film tape made of an insulating resin that closes the hole 4 is removed, and the metal plate 1 and the reinforcing layer 3 are cut (cut) at the hole 4 portion. At the same time, the individual cathode terminal portions 10 are cut to form individual solid electrolytic capacitors (FIGS. 2 (12) and 3 (3)).

(2) Operation and effect As described above, a concave portion is formed on one surface of a metal plate to expose the base metal, and an oxide film layer, a solid electrolyte layer, a cathode terminal are provided in the concave portion, and a groove shape formed on the metal plate. By metal-plating the inner surface of the hole and cutting at the position of the hole, the metal-plated surface 5 of the inner surface of the hole is exposed to the outside of both ends of the solid electrolytic capacitor, and becomes the external electrode of the anode as it is. Since the external electrode of this anode is directly formed on the metal plate that becomes the anode part of the solid electrolytic capacitor, the area of the anode terminal part that does not contribute to the capacitance of the solid electrolytic capacitor can be made extremely small.

  In addition, a concave portion is formed on one side of the metal plate provided with the protective layer to expose the base metal, and an oxide film layer, a solid electrolyte layer, and a cathode terminal are provided in the concave portion, thereby providing a capacity holding portion as a capacitor. The cathode terminal part is formed near the interface between the oxide film and the solid electrolyte layer. The distance between the capacitor holding part and the cathode terminal part to the circuit pattern or LSI device is short, and the current draw inside the capacitor is reduced. Since the rotation path is shortened, the transient response to the unstable power supply voltage is improved.

  In particular, the reinforcing layer 2 is added to the metal plate 1 and the hole 4 does not penetrate the metal plate 1 but penetrates the metal plate 1. The metal plate 1 is stable and the processing accuracy and efficiency can be maintained.

  In particular, since the conventional sandwich structure is not required, the anode external electrode is directly formed on the metal plate that becomes the anode part of the solid electrolytic capacitor, so that the miniaturization is realized and the size is reduced to about 5 mm square. Can be reduced. In addition, when metal plating is performed not only on the inner surface of the hole but also on the surface of the metal plate exposed to the periphery thereof, the external electrode of the anode is formed on the thickness of the cathode external electrode and the formation surface of the cathode terminal portion of the metal plate. Control the height of the external electrode of the formed anode (that is, the thickness of the plating) so that the height of the external terminal of the anode and the cathode is the same plane position, and the entire plane including the external terminal is made the same flat shape without waste This makes it possible to place solid electrolytic capacitors close to the current supply target LSI, such as stacking them vertically, such as between the substrate and the back surface of the substrate, or by direct wiring using bump electrodes. This further shortens the current path and further improves the transient response.

  In addition, the anode external electrode and the cathode terminal portion are close to each other, and the effect of canceling the induced magnetic field generated when current flows through the anode external electrode and the cathode terminal portion is increased, thereby reducing the ESL of the solid electrolytic capacitor. be able to.

  Moreover, in this embodiment, the metal-plating is not melt | dissolved at the time of the etching for a surface expansion process by obstruct | occluding the cut hole 4 with the sealing member P before a surface expansion process, and it serves as an anode terminal reliably. On the other hand, by removing the sealing member P before cutting into individual pieces, the cutting process becomes smooth and highly accurate, and the adhesion of impurities to the individual pieces of the product can be minimized.

  Furthermore, in this embodiment, the periphery of the cathode terminal portion 10 is covered with the insulating resin 11 (FIG. 2 (11)), so that the insulating resin 11 enters the gap between the concave portion and the cathode external electrode, thereby insulating the anode and the cathode. In addition, by covering a part of the cathode external electrode constituting the cathode terminal portion 10 with the insulating resin 11, the bonding strength of the cathode external electrode can be increased.

(3) Other Embodiments The present invention is not limited to the above-described embodiment, and includes the following embodiments and other embodiments. For example, it is possible to omit covering the portion of the cathode terminal portion 10 excluding the externally exposed portion that should be exposed to the outside with the insulating resin 11.

  Also, instead of metal plating the inner surface of the hole and closing the inlet of the hole with a sealing member, the inside of the hole is filled with a conductive material such as copper, and the conductive material is filled at the hole portion. May be cut into pieces in the form of half cuts. The means for filling the conductive material is arbitrary. For example, a copper plate having a shape corresponding to the groove-like hole is filled with a conductive adhesive. In addition, the conductive material can be filled into the groove-like holes by printing the conductive paste. In this way, the conductive material filled in the entire inside of the groove-shaped hole formed in the metal plate is exposed to the outside of both ends of the solid electrolytic capacitor of the piece by cutting at the position of the hole, and the external electrode of the anode as it is This eliminates the need for a sealing member at the time of etching rather than plating the inner surface of the hole, simplifies the process, and improves production efficiency and cost.

  In addition, when cutting holes, the metal layer is exposed not only to the inner surface of the hole but also to the peripheral metal plate by removing the protective layer with a certain width around the hole to expose the metal plate. (FIG. 3) When the surface of the protection 3 is mounted as a bottom surface toward a substrate or the like, the bottom surface can be used as an external electrode, so that the degree of freedom of component arrangement is further increased.

Sectional drawing which shows the manufacturing method (first half) of the solid electrolytic capacitor in embodiment of this invention. Sectional drawing which shows the manufacturing method (latter half) of the solid electrolytic capacitor in embodiment of this invention. The perspective view which shows the manufacturing method (part) of the solid electrolytic capacitor in embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Metal plate 2 ... Reinforcement layer 3 ... Protective layer 4 ... Hole 5 ... Copper plating surface 6 ... Recess 7 ... Oxide film layer 8 ... Solid electrolyte layer 10 ... Cathode terminal part 11 ... Resin P ... Sealing member

Claims (8)

A reinforcing layer is formed on one side of the metal plate made of valve metal, and a protective layer is formed on the opposite side.
Forming a plurality of groove-like holes that penetrate the metal plate by cutting from the surface of the protective layer but do not penetrate the reinforcing layer,
Apply metal plating to at least the inner surface of the hole,
By exposing the metal plate to form the anode portion on the inner surface of the recess by forming recesses at predetermined intervals on the surface of the metal plate between the adjacent holes,
Expanding the surface of the inner surface of the recess, forming an oxide film layer on the surface,
Forming a solid electrolyte layer on the oxide film layer in the recess,
Forming a cathode terminal on the solid electrolyte layer;
A solid electrolytic capacitor, wherein the metal plate and the reinforcing layer are cut at the groove-shaped hole portion to form a solid electrolytic capacitor as a single piece.   2. The solid electrolytic capacitor according to claim 1, wherein a portion of the cathode terminal portion excluding a predetermined external exposed portion to be exposed to the outside is covered with an insulating resin.   After the cut hole is closed with a sealing member, the surface enlargement process and the subsequent steps are performed, and the sealing member is removed before the cutting into individual solid electrolytic capacitors. The solid electrolytic capacitor according to claim 1 or 2. A reinforcing layer is formed on one side of the metal plate made of valve metal, and a protective layer is formed on the opposite side.
Forming a plurality of groove-like holes that penetrate the metal plate by cutting from the surface of the protective layer but do not penetrate the reinforcing layer,
Filling the hole with a conductive material;
By exposing the metal plate to form the anode portion on the inner surface of the recess by forming recesses at predetermined intervals on the surface of the metal plate between the adjacent holes,
Expanding the surface of the inner surface of the recess, forming an oxide film layer on the surface,
Forming a solid electrolyte layer on the oxide film layer in the recess,
Forming a cathode terminal on the solid electrolyte layer;
A solid electrolytic capacitor, wherein the conductive material, the metal plate, and the reinforcing layer that are filled in the groove-shaped hole portion are cut into individual solid electrolytic capacitors. Forming a reinforcing layer on one side of a metal plate made of valve metal, and forming a protective layer on the opposite side;
Forming a plurality of groove-shaped holes that penetrate the metal plate by cutting from the surface of the protective layer but do not penetrate the reinforcing layer;
Applying metal plating to at least the inner surface of the hole;
A step of exposing the metal plate to form an anode portion on the inner surface of the recess by forming recesses at predetermined intervals on the surface of the metal plate between the adjacent holes;
Expanding the valve metal ingot on the inner surface of the recess, and forming an oxide film layer on the surface;
Forming a solid electrolyte layer on the oxide film layer in the recess;
Forming a cathode terminal on the solid electrolyte layer;
Cutting the metal plate and the reinforcing layer at the groove-shaped hole portion to form a solid electrolytic capacitor as a piece;
The manufacturing method of the solid electrolytic capacitor characterized by including this.   6. The method of manufacturing a solid electrolytic capacitor according to claim 5, further comprising a step of covering a portion of the cathode terminal portion excluding a predetermined external exposed portion to be exposed to the outside with an insulating resin. Before the surface expansion treatment, the step of closing the hole that has been cut with a sealing member;
Removing the sealing member before the cutting into individual solid electrolytic capacitors;
The method for producing a solid electrolytic capacitor according to claim 5 or 6, comprising: Forming a reinforcing layer on one side of a metal plate made of valve metal, and forming a protective layer on the opposite side;
Forming a plurality of groove-shaped holes that penetrate the metal plate by cutting from the surface of the protective layer but do not penetrate the reinforcing layer;
Filling the inside of the hole with a conductive material;
A step of exposing the metal plate to form an anode portion on the inner surface of the recess by forming recesses at predetermined intervals on the surface of the metal plate between the adjacent holes;
Expanding the surface of the inner surface of the recess, and forming an oxide film layer on the surface;
Forming a solid electrolyte layer on the oxide film layer in the recess;
Forming a cathode terminal on the solid electrolyte layer;
Cutting the filled conductive material, the metal plate, and the reinforcing layer at the groove-shaped hole portion to form an individual solid electrolytic capacitor;
The manufacturing method of the solid electrolytic capacitor characterized by including this.

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