Solid electrolytic capacitor and method for manufacturing solid electrolytic capacitor

Abstract

The disclosed manufacturing method is a method for manufacturing a solid electrolytic capacitor including at least one solid electrolytic capacitor element (100) including a cathode part (130) and an anode part (110) including an anode lead-out part (111a). The manufacturing method includes: a step (i) in which one anode connection member (211) comprising a metal that is not a valve metal is connected to an anode lead-out section (111a) of at least one solid electrolytic capacitor element (100); a step (ii) in which the exterior body (140) is formed so as to cover at least a portion of the at least one solid electrolytic capacitor element (100) and the anode connection member (211); a step (iii) for exposing a part of the surface of the anode connection member (211) as a connection surface (211a) from the exterior body (140) by removing a part of the exterior body (140); and a step (iv) for connecting the anode lead terminal (212) and the connection surface (211a).

Description

Technical Field

[0001] The present disclosure relates to a solid electrolytic capacitor and a method for manufacturing the solid electrolytic capacitor. Background Art

[0002] A solid electrolytic capacitor generally includes a solid electrolytic capacitor element, a lead terminal connected to the solid electrolytic capacitor element, and an outer casing that seals the solid electrolytic capacitor element. Various proposals have been made in the past regarding the connection method between the lead terminal and the solid electrolytic capacitor element.

[0003] Patent document 1 (Japanese Patent Application Publication No. 2013-515381) discloses "a method for forming a solid electrolytic capacitor, comprising: forming an anode including a valve metal or a conductive oxide of a valve metal, wherein an anode lead extension is formed protruding from the anode; forming a dielectric on the anode; forming a cathode layer on the dielectric; accommodating the anode, the dielectric, and the cathode layer in a non-conductive material container; exposing the anode lead extension on a side surface outside the container; bonding a conductive metal layer to the anode lead extension; and electrically connecting a preformed solid metal terminal to the conductive metal layer on the side surface."

[0004] Patent document 2 (Japanese Patent Publication No. 2008-235413) discloses "a solid electrolytic capacitor, comprising: a flat element, in which a conductive polymer is used for a solid electrolyte, and an anode electrode portion and a cathode electrode portion are arranged with an insulating portion therebetween; an anode common terminal and a cathode common terminal, and the anode electrode portion and the cathode electrode portion arranged in the element are respectively joined; and an insulating outer resin, which integrally covers the above-mentioned element, the anode common terminal and the cathode common terminal in a state where a portion of the anode common terminal and the cathode common terminal are respectively exposed, wherein in the solid electrolytic capacitor, cutout portions are provided at both ends of the end portion of the cathode electrode portion in the direction connecting the anode electrode portion and the cathode electrode portion of the above-mentioned element, and side wall portions are provided so that both ends of the element mounting portion of the cathode common terminal carrying the cathode electrode portion of the element are bent and abut against the side surfaces of the cutout portion provided in the cathode electrode portion of the above-mentioned element."

[0005] Patent document 3 (Japanese Patent Publication No. 2004-87893) discloses "a solid electrolytic capacitor comprising: a capacitor element, wherein an insulating portion is provided on an anode body made of a valve-acting metal and separated into an anode portion and a cathode portion, and a dielectric oxide film layer, a solid electrolyte layer, and a cathode layer are sequentially stacked and provided on the surface of the cathode portion; an anode common terminal, which integrally connects the anode portions of each capacitor element in a state where a plurality of capacitor elements are stacked; a cathode common terminal, which also integrally connects the cathode portions; and an insulating outer resin, which integrally covers the plurality of capacitor elements in a state where a portion of the anode common terminal and the cathode common terminal are respectively exposed to the outer surface, wherein the connection between the anode portion of each capacitor element and the anode common terminal is performed by resistance welding via a through hole provided on a bonding surface of the anode common terminal on which the anode portion of the capacitor element is mounted."

[0006] Prior Art Literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application No. 2013-515381

[0009] Patent Document 2: Japanese Patent Application Publication No. 2008-235413

[0010] Patent Document 3: Japanese Patent Application Publication No. 2004-87893 Summary of the invention

[0011] -Problems that the invention aims to solve-

[0012] There is a demand for further improvement in the volume capacity density (electrostatic capacitance per unit volume) of solid electrolytic capacitors. One object of the present disclosure is to provide a solid electrolytic capacitor having a high volume capacity density and a method for manufacturing the same.

[0013] -Methods used to solve the problem-

[0014] One aspect of the present disclosure relates to a method for manufacturing a solid electrolytic capacitor. The method is a method for manufacturing a solid electrolytic capacitor including at least one solid electrolytic capacitor element, wherein the at least one solid electrolytic capacitor element includes a cathode portion and an anode portion including an anode lead portion, and the method for manufacturing a solid electrolytic capacitor includes:

[0015] Step (i), connecting an anode connecting member made of a metal other than a valve metal to the anode lead-out portion of the at least one solid electrolytic capacitor element;

[0016] Step (ii), forming an outer casing so as to cover at least one solid electrolytic capacitor element and at least a portion of the anode connecting member;

[0017] (iii), removing a portion of the outer casing so that a portion of the surface of the anode connecting member is exposed from the outer casing as a connecting surface; and

[0018] The step (iv) is to connect an anode lead terminal to the connection surface of the anode connection member.

[0019] Another aspect of the present disclosure relates to a solid electrolytic capacitor. The solid electrolytic capacitor comprises:

[0020] At least 1 solid electrolytic capacitor element;

[0021] an anode connecting member composed of a metal other than valve metal;

[0022] an outer casing configured to cover the at least one solid electrolytic capacitor element and the anode connecting member; and

[0023] Anode lead terminal, exposed to the outside,

[0024] The solid electrolytic capacitor element comprises: a cathode portion and an anode portion including an anode lead portion,

[0025] The anode connecting member is connected to the anode lead-out portion,

[0026] A portion of the surface of the anode connecting member is exposed from the outer casing as a connecting surface,

[0027] The connection surface of the anode connection member is connected to the anode lead terminal.

[0028] -Effects of the Invention-

[0029] According to the present disclosure, a solid electrolytic capacitor having a high volume capacity density can be obtained.

[0030] The novel features of the present invention are described in the appended claims, but the present invention will be better understood from the following detailed description both as to structure and content, taken in conjunction with other objects and features of the present invention, with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1A One step of an example of the manufacturing method of Embodiment 1 is schematically shown.

[0032] Figure 1B Schematically showing the Figure 1A A process after the process.

[0033] Figure 1C Schematically showing the Figure 1B A process after the process.

[0034] Figure 1D An example of a solid electrolytic capacitor manufactured by the manufacturing method of Embodiment 1 is schematically shown.

[0035] Figure 2 A cross section of an example of a solid electrolytic capacitor element used in the manufacturing method of Embodiment 1 is schematically shown.

[0036] Figure 3A An example of the shape of the connection surface exposed by step (iii) is schematically shown.

[0037] Figure 3B An example of step (iii-b) is schematically shown.

[0038] Figure 4 Another example of the solid electrolytic capacitor manufactured by the manufacturing method of Embodiment 1 is schematically shown.

[0039] Figure 5A One step of another example of the production method of Embodiment 1 is schematically shown.

[0040] Figure 5B Another example of the solid electrolytic capacitor manufactured by the manufacturing method of Embodiment 1 is schematically shown.

[0041] Fig. 6A One step of the manufacturing method of the second embodiment is schematically shown.

[0042] Figure 6B An example of a solid electrolytic capacitor manufactured by the manufacturing method of Embodiment 2 is schematically shown.

[0043] Figure 7 A cross section of an example of a solid electrolytic capacitor element used in the manufacturing method of the second embodiment is schematically shown. DETAILED DESCRIPTION

[0044] Hereinafter, the embodiments involved in the present disclosure will be described with examples, but the present disclosure is not limited to the examples described below. In the following description, there are cases where specific numerical values ​​and materials are illustrated, but other numerical values ​​and other materials can also be applied as long as the effect of the present disclosure can be obtained. In this specification, the description of "numerical value A to numerical value B" includes numerical value A and numerical value B, which can be replaced by "numerical value A or above and numerical value B or below". In the following description, when the lower limit and upper limit of numerical values ​​related to specific physical properties, conditions, etc. are illustrated, as long as the lower limit is not above the upper limit, any one of the illustrated lower limits and any one of the illustrated upper limits can be arbitrarily combined. In the following description, when examples of structural elements and examples of methods are listed, as long as there is no special description, only one of the examples listed can be used, or multiple of the examples listed can be used in combination. In this specification, in the method of connecting two components, a method of directly connecting two components and a method of connecting two components through a layer, etc. are included. For examples of this layer, a conductive layer (solder layer, metal paste layer, etc.) is included.

[0045] (Method for manufacturing solid electrolytic capacitor)

[0046] The manufacturing method of the present embodiment is a manufacturing method of a solid electrolytic capacitor including at least one solid electrolytic capacitor element, wherein the solid electrolytic capacitor element includes: a cathode portion; and an anode portion including an anode lead portion. Hereinafter, the manufacturing method is sometimes referred to as "manufacturing method (M)". The solid electrolytic capacitor manufactured by the manufacturing method (M) is not particularly limited.

[0047] The manufacturing method (M) includes steps (i), (ii), (iii) and (iv) in sequence. These steps will be described later. In the manufacturing method (M), the anode lead-out portion and the anode lead terminal are connected via an anode connecting member made of a metal that is not a valve metal (a metal that does not have a valve function). Therefore, the anode connecting member and the anode lead terminal are easily connected, and the anode connecting member and the anode lead terminal can be connected reliably and firmly.

[0048] Furthermore, when the solid electrolytic capacitor includes a plurality of solid electrolytic capacitor elements, the ends of the anode lead portions are collectively connected to one anode connecting member in step (i), thereby significantly reducing manufacturing cost and time compared to connecting each end to a separate anode connecting member.

[0049] (Process (i))

[0050] Step (i) is a step of connecting an anode connecting member made of a metal that is not a valve metal (a metal that does not have a valve function) to the anode lead portion of the at least one solid electrolytic capacitor element. Examples of the anode lead portion include a portion of the anode foil (anode body) described below and an anode lead wire.

[0051] The so-called metal with valve function refers to a metal that exhibits rectification properties through a relatively stable oxide film formed on the surface. Metals with valve function are called valve metals. Examples of valve metals include titanium, tantalum, aluminum, and niobium. Metals that do not have valve function are metals that are not valve metals. Examples of metals that do not have valve function include copper and copper alloys. That is, the metal that does not have valve function can be at least one selected from the group consisting of copper and copper alloys, or copper or copper alloys. Copper and copper alloys are preferred in terms of high conductivity and easy connection.

[0052] The method for connecting the anode connecting member and the anode lead-out portion is not particularly limited, and a known method can be used. Examples of the connection method include connection based on welding, connection using a conductive paste, connection using solder, etc. In addition, examples of welding include laser welding, resistance welding, and other welding methods (the same applies to the welding described below). The conductive paste can be a mixture of a resin and conductive particles (carbon particles, metal particles, etc.). The conductive paste can also be a metal paste containing metal particles (such as a silver paste).

[0053] The solid electrolytic capacitor element is not particularly limited. Examples of the solid electrolytic capacitor element include a capacitor having a foil including a valve metal in the anode portion and a capacitor having a sintered body in the anode portion. That is, the anode portion may also include a sintered body including a valve metal.

[0054] The solid electrolytic capacitor element can be formed by a known method. The number of solid electrolytic capacitor elements contained in the solid electrolytic capacitor can be either 1 or more than 2. There is no upper limit on the number of solid electrolytic capacitor elements contained in the solid electrolytic capacitor, and it can be less than 10. Multiple solid electrolytic capacitor elements are usually connected in parallel.

[0055] The solid electrolytic capacitor may also include a plurality of stacked solid electrolytic capacitor elements. In this case, in step (i), the ends of the anode lead portions of the plurality of solid electrolytic capacitor elements may be collectively connected to the anode connecting member. For example, in the case where the anode lead portion is composed of a metal foil, the ends of the plurality of anode lead portions may overlap and be connected to the anode connecting member. The ends of the anode lead portions are connected to each other. These connection methods are not particularly limited. Examples of connection methods include connection based on welding, connection using a metal paste (e.g., silver paste), connection using solder, and the like. Alternatively, the ends of the anode lead portions may be physically connected by a method such as a method of surrounding with an anode connecting member.

[0056] When the solid electrolytic capacitor includes a plurality of stacked solid electrolytic capacitor elements, the anode connecting member may be sandwiched between the stacked anode lead portions, and the cathode connecting member may be sandwiched between the stacked cathode portions.

[0057] (Step (ii))

[0058] Step (ii) is a step of forming an outer casing to cover at least a portion of the at least one solid electrolytic capacitor element and the anode connecting member. The outer casing and the method for forming the outer casing are not particularly limited, and a known outer casing and a known method can be used. Examples of outer casings will be described later. The outer casing can be formed using molding techniques such as transfer molding, compression molding, and injection molding. The outer casing formed by step (ii) includes a portion that becomes the outer casing of the manufactured solid electrolytic capacitor and a portion that is removed by step (iii).

[0059] (Process (iii))

[0060] Step (iii) is a step of removing a portion of the outer casing so that a portion of the surface of the anode connecting member is exposed from the outer casing as a connecting surface. Step (iii) generally includes a cutting step of cutting a portion of the outer casing. By including this step (iii), the volume of the outer casing can be reduced without changing the volume of the portion of the solid electrolytic capacitor element that generates electrostatic capacitance, and the volume capacity density can be increased. The outer casing is removed (e.g., cut) so that the direction LD (refer to Figure 1B ) is shortened. For example, the outer casing (and, if necessary, the anode connecting member) may be cut along a direction perpendicular to the direction LD.

[0061] The method for performing the cutting process is not particularly limited. The cutting process can be performed using a blade (e.g., a circular blade). For example, the cutting process can also be performed using a dicing blade used for cutting a semiconductor wafer. That is, the cutting process can also be performed using a dicing machine for cutting a semiconductor wafer or a similar device.

[0062] The width of the cut is not particularly limited. In addition, the distance L between the cathode portion and the cut surface during cutting is not particularly limited. The shorter the distance L is, the higher the volume capacity density can be.

[0063] Step (iii) may include step (iii-a) of removing a portion of the outer casing by cutting the outer casing and the anode connecting member together. The cutting step in step (iii-a) allows a portion of the surface of the anode connecting member to be exposed from the outer casing as a connection surface.

[0064] Step (iii) may further include, after step (iii-a), step (iii-b) of removing the portion of the outer casing exposed on the cut surface so that a portion of the anode connecting member protrudes from the outer casing. By protruding a portion of the anode connecting member from the outer casing, the area of ​​the anode connecting member exposed from the outer casing (the area of ​​the contact surface) can be increased. As a result, the anode connecting member and the anode lead terminal can be easily and firmly connected.

[0065] The method for performing step (iii-b) is not particularly limited. Examples of methods for performing step (iii-b) include sandblasting, laser irradiation (laser ablation, etc.). Through step (iii-b), the length (height) H of the anode connecting member protruding from the outer body can be 50 μm or more or 100 μm or more. By setting the length H to be 50 μm or more, the anode connecting member and the anode lead terminal can be particularly easily and firmly connected. The upper limit of the length H is not particularly limited, but from the perspective of manufacturing cost and manufacturing time, it can be 200 μm or less or 150 μm or less.

[0066] When the step (iii-b) is performed, the entire surface of the outer casing at the cut surface may be removed, or only a portion of the surface of the outer casing at the cut surface may be removed. For example, a portion of the surface of the outer casing at the cut surface may be removed in the shape of a groove. The relationship between the width of the groove to be formed, the width of the connection surface, and the width of the anode lead terminal is described in Embodiment 1.

[0067] (Process (iv))

[0068] Step (iv) is a step of connecting the anode lead terminal to the connection surface of the anode connection member. Through step (iv), the anode portion and the anode lead terminal are electrically connected via the anode connection member. The method for connecting the anode lead terminal to the connection surface of the anode connection member is not particularly limited. Examples of the connection method include connection based on welding, connection using a metal paste (e.g., silver paste), connection using solder, etc. The anode lead terminal is assembled from the outside. That is, the anode lead terminal is exposed to the outside.

[0069] The solder (e.g., solder paste) is not particularly limited, and a known lead-free solder can be used. For the solder, a solder with a higher solidus temperature (lead-free solder) can also be used. For example, a solder that does not remelt during the reflow process performed when installing electronic components can also be used. By using such a solder, it is possible to suppress the occurrence of short circuits, etc. during the reflow process. The solidus temperature of the solder with a higher solidus temperature can be either above 230°C or below 300°C. For the solder with a higher solidus temperature, commercially available solders and known solders can be used. Examples of solders with a high solidus temperature of 230°C or higher include Sn-5Sb or Sn-10Sb solders of the Sn-Sb type.

[0070] In the above description, a process of exposing a part of the surface of the anode connecting member as a connection surface by removing a part of the outer body is described. The manufacturing method (M) may also include a process of exposing a part of the surface of the cathode connecting member as a connection surface by removing a part of the outer body. According to this process, the volume capacity density can be further improved. In this case, the steps (i) to (iv) may also be performed as follows. First, the step (i) further includes a step of connecting a cathode connecting member composed of a metal that is not a valve metal (a metal that does not have a valve function) to the cathode portion. Next, in the step (ii), the outer body is formed to cover the at least one solid electrolytic capacitor element, at least a part of the anode connecting member, and at least a part of the cathode connecting member. Next, the step (iii) further includes a step of exposing a part of the surface of the cathode connecting member from the outer body as a connection surface by removing another part of the outer body. Next, the step (iv) further includes a step of connecting the cathode lead terminal to the above-mentioned connection surface of the cathode connecting member.

[0071] The method of connecting the cathode connecting member to the cathode portion in step (i) is not limited and can be performed by a known method. For example, the two can be connected using a metal paste (e.g., a silver paste). Since steps (ii) to (iv) can be implemented by the same method as the method described for steps (ii) to (iv) with respect to the anode connecting member, repeated descriptions are omitted. In step (iv), the cathode lead terminal is assembled from the outside. That is, the cathode lead terminal is exposed to the outside.

[0072] The solid electrolytic capacitor can be obtained by the manufacturing method (M). The anode lead terminal and the cathode lead terminal each function as a connection terminal.

[0073] (Solid electrolytic capacitor)

[0074] Hereinafter, the solid electrolytic capacitor of the present embodiment is sometimes referred to as a "solid electrolytic capacitor (E)". The solid electrolytic capacitor (E) can be manufactured by the manufacturing method (M). Since the matters described for the manufacturing method (M) can be applied to the solid electrolytic capacitor (E), repeated descriptions are sometimes omitted. In addition, the matters described for the solid electrolytic capacitor (E) can also be applied to the manufacturing method (M). In addition, the solid electrolytic capacitor (E) can also be manufactured by a method other than the manufacturing method (M).

[0075] The solid electrolytic capacitor (E) comprises: at least one solid electrolytic capacitor element; an anode connecting member, which is composed of a metal that is not a valve metal (a metal that does not have a valve function); an outer casing, which is configured to cover at least one solid electrolytic capacitor element and the anode connecting member; and an anode lead terminal, which is exposed to the outside. The solid electrolytic capacitor element includes a cathode portion and an anode portion, and the anode portion includes an anode lead portion. The anode connecting member is connected to the anode lead portion. The surface of a portion of the anode connecting member is exposed from the outer casing as a connection surface. The connection surface of the anode connecting member is connected to the anode lead terminal.

[0076] According to the solid electrolytic capacitor (E), the volume of the outer casing can be reduced without changing the volume of the portion of the solid electrolytic capacitor element that generates electrostatic capacitance, thereby improving the volume capacity density.

[0077] The solid electrolytic capacitor (E) may include a plurality of stacked solid electrolytic capacitor elements. In this case, the ends of the plurality of anode lead portions of the plurality of solid electrolytic capacitor elements may be collectively connected to the anode connecting member.

[0078] The anode portion may include a sintered body containing a valve metal. Alternatively, the anode portion may include a foil of a valve metal.

[0079] The part of the anode connecting member may protrude from the outer casing. This structure can be achieved by step (iii-b).

[0080] The solid electrolytic capacitor (E) may further include: a cathode connecting member, which is covered by an outer casing and is composed of a metal that is not a valve metal (a metal that does not have a valve function); and a cathode lead terminal, which is exposed to the outside. The cathode connecting member may be connected to the cathode portion. A portion of the surface of the cathode connecting member may be exposed from the outer casing as a connecting surface. The above-mentioned connecting surface of the cathode connecting member may be connected to the cathode lead terminal.

[0081] The following describes examples of structural elements used in the solid electrolytic capacitor (E) and the manufacturing method (M) of the present embodiment. In addition to the characteristic parts of the present disclosure, structural elements of known solid electrolytic capacitors can also be applied to the structural elements used in the solid electrolytic capacitor (E) and the manufacturing method (M).

[0082] (Solid electrolytic capacitor element)

[0083] The solid electrolytic capacitor element includes an anode portion, a cathode portion, and a dielectric layer. The cathode portion includes an electrolyte layer and may further include a cathode lead layer.

[0084] (Anode)

[0085] The anode portion includes an anode lead-out portion and an anode body. The anode lead-out portion is electrically connected to the anode body. The anode body can be formed using a valve metal or a metal containing a valve metal.

[0086] For the anode body, a metal foil (a foil containing a valve metal or a foil composed of a valve metal) can also be used. The thickness of the metal foil (anode body) is not particularly limited. The thickness of the metal foil can be, for example, 15 μm or more or 80 μm or less, or 300 μm or less or 250 μm or less. The surface of at least a portion of the metal foil (anode body) can also be roughened by electrolytic etching or the like. In this case, the anode body has a porous portion on its surface. A preferred example of an anode body as a metal foil is aluminum foil. In the case where the anode body is a metal foil, one end of the metal foil can function as an anode lead-out portion.

[0087] The anode body may also be a sintered body formed by sintering particles of a material. Examples of particles of a material include particles of a valve metal and particles of an alloy containing a valve metal. A preferred example of an anode body as a sintered body is a sintered body of tantalum. When the anode body is a sintered body, an anode lead may be used as an anode lead. One end of the anode lead is buried in the sintered body, and the other end protrudes from the end face of the sintered body.

[0088] (Dielectric layer)

[0089] The dielectric layer is formed on at least a portion of the surface of the anode body. For example, the dielectric layer can be formed by anodizing the surface of the anode body (anodizing by chemical formation treatment). In this case, the dielectric layer contains an oxide of a valve metal. For example, when aluminum is used as the valve metal, the dielectric layer can contain aluminum oxide. When there is a porous portion on the surface of the anode body, the dielectric layer can also be formed on at least a portion of the surface of the porous portion of the anode body.

[0090] (Cathode)

[0091] The cathode portion includes an electrolyte layer and a conductive layer adjacent to the electrolyte layer. The conductive layer only needs to be formed to cover at least a portion of the electrolyte layer, and can also be formed to cover the entire surface of the electrolyte layer. Examples of the conductive layer include a carbon-containing layer, a metal-containing layer, and the like. The metal-containing layer can be formed by a metal paste (e.g., a silver paste). The conductive layer may also include a carbon-containing layer formed on the electrolyte layer, and a metal-containing layer (e.g., a silver-containing layer) formed on the carbon-containing layer.

[0092] (Electrolyte layer)

[0093] The electrolyte layer (solid electrolyte layer) is configured to cover at least a portion of the dielectric layer. The electrolyte layer includes, for example, a manganese compound and a conductive polymer. Examples of conductive polymers include polypyrrole, polythiophene, polyfuran, polyaniline, polyacetylene, polyphenylene, polyphenylene vinylene, polyacene, polythiophene ethylene, and derivatives thereof. A preferred example of the conductive polymer is poly (3,4-ethylenedioxythiophene).

[0094] The conductive polymer may be contained in the solid electrolyte layer together with a dopant. A preferred example of the dopant is a polymer anion derived from polystyrene sulfonic acid. A preferred example of the electrolyte layer is formed using poly(3,4-ethylenedioxythiophene) (PEDOT) doped with polystyrene sulfonic acid (PSS).

[0095] (Anode connecting member and cathode connecting member)

[0096] The anode connecting member and the cathode connecting member can be formed of a metal other than a valve metal (e.g., copper, copper alloy, etc.). The thickness of the anode connecting member and the cathode connecting member can also be in the range of 25 μm to 200 μm (e.g., in the range of 25 μm to 100 μm). Thin metal sheets used in known lead terminals can also be used to form the anode connecting member and the cathode connecting member.

[0097] (outer body)

[0098] The outer casing is not particularly limited, and a known outer casing can be used. The outer casing includes an outer casing resin. Examples of the outer casing resin include curable resins, engineering plastics, and the like. Examples of curable resins (e.g., thermosetting resins) include epoxy resins, phenolic resins, silicone resins, melamine resins, urea resins, alkyd resins, polyurethanes, and unsaturated polyesters. Examples of engineering plastics include general engineering plastics and super engineering plastics. Examples of engineering plastics include polyimides and polyamide-imides.

[0099] The outer casing may contain other additives such as inorganic fillers in addition to the outer casing resin. That is, at least a portion of the outer casing may also be composed of a resin composition. Examples of inorganic fillers include silica (fused silica, etc.), talc, calcium carbonate, aluminum oxide, etc.

[0100] Hereinafter, examples of embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In addition, the examples described below can be changed based on the above description. In addition, the matters described below can also be applied to the above embodiments. In addition, in the embodiments described below, non-essential structural elements in the solid electrolytic capacitor of the present disclosure can also be omitted. In addition, for ease of understanding, in the following figures, the illustration of a part of the components is sometimes omitted.

[0101] (Implementation method 1)

[0102] In the first embodiment, a method for manufacturing an example of a solid electrolytic capacitor including a plurality of solid electrolytic capacitor elements is described.

[0103] First, if Figure 1A As shown, a plurality of solid electrolytic capacitor elements 100 are stacked and connected to an anode connecting member 211 and a cathode connecting member 221 (step (i)). Step (i) can be performed in the same manner as a known method of stacking a plurality of solid electrolytic capacitor elements 100 and connecting them to an anode lead terminal and a cathode lead terminal. The anode connecting member 211 and the cathode connecting member 221 are connected to the sheet 200. The anode connecting member 211 and the cathode connecting member 221 can be formed by cutting and bending a portion of the sheet 200. The sheet 200 is a sheet made of a metal that is not a valve metal (a metal that does not have a valve function).

[0104] The anode connecting member 211 includes a portion 211x surrounding the stacked anode lead-out portions 111a. The cathode connecting member 221 includes two sidewall portions 221y, which are arranged to sandwich the side surfaces of the stacked solid electrolytic capacitor elements 100. However, the shapes of the anode connecting member 211 and the cathode connecting member 221 may be Figure 1AShapes other than those shown.

[0105] Figure 2 , a cross-sectional view of an example of a solid electrolytic capacitor element 100 is schematically shown. The solid electrolytic capacitor element 100 includes: an anode portion 110 including an anode body (anode foil) 111 and an anode lead portion 111a; a dielectric layer 120 covering at least a portion of the anode body 111; and a cathode portion 130 covering at least a portion of the dielectric layer 120. The cathode portion 130 includes: an electrolyte layer (solid electrolyte layer) 131 covering at least a portion of the dielectric layer 120; and a conductive layer 132 formed on the electrolyte layer 131.

[0106] The conductive layers 132 of the stacked plurality of solid electrolytic capacitor elements 100 are connected to each other. At least one conductive layer 132 is connected to the cathode connecting member 221 by metal paste or the like. One end of the metal foil constituting the anode body 111 functions as the anode lead-out portion 111a. The anode lead-out portions 111a of the plurality of solid electrolytic capacitor elements 100 overlap and are connected to each other. At least one anode lead-out portion 111a is connected to the anode connecting member 211 by welding or the like.

[0107] Next, if Figure 1B As shown in FIG. 1 , outer casing 140 is formed to cover solid electrolytic capacitor element 100 , at least a portion of anode connecting member 211 , and at least a portion of cathode connecting member 221 (step (ii)). Figure 1B In the embodiment, the surface of the outer package 140 on the end surface side of the anode lead portion 111a of the solid electrolytic capacitor element 100 is defined as the front surface 140f, and the surface opposite to the front surface 140f is defined as the rear surface 140r. The direction connecting the front surface 140f and the rear surface 140r is defined as the direction LD.

[0108] Next, if Figure 1C As shown, a portion of the outer casing 140 is removed so that a portion of the surface of the anode connecting member 211 is exposed from the outer casing 140 as the connecting surface 211a (process (iii)). In addition, a portion of the surface of the cathode connecting member 221 is removed so that a portion of the surface of the cathode connecting member 221 is exposed from the outer casing 140 as the connecting surface 221a. The removal of a portion of the outer casing is performed by cutting the outer casing 140 and the anode connecting member 211 together. The removal of the other portion of the outer casing is performed by cutting the outer casing 140 and the cathode connecting member 221 together. These cuts are performed so that the length of the outer casing 140 in the direction LD becomes shorter. By these cuts, cut surfaces 140sa and 140sb are formed. On the cut surface 140sa, the connecting surface 211a is exposed, and on the cut surface 140sb, the connecting surface 221a is exposed.

[0109] Figure 3A FIG. 2 shows an example of the connection surface (end surface) 211 a of the anode connection member 211 exposed in step (iii). Figure 3A The cross section of the connection surface 211a in the example shown is C-shaped and has a shape surrounding the overlapped anode lead-out portion 111a. Such a connection surface 211a can be formed by bending the anode connection member 211 into a substantially cylindrical shape in step (i). In this way, the anode lead-out portion 111a and the anode connection member 211 can be firmly fixed. In addition, the shape of the connection surface 211a is not limited to Figure 3A The shape shown may be a substantially linear shape or a substantially U-shape. The shape of the connection surface 221 a varies depending on the shape of the anode connection member 211 in step (i).

[0110] When performing the above step (iii-b), the entire surface of the outer casing 140 at the cut surface 140sa (or the cut surface 140sb) may be removed, or only a portion of the surface of the outer casing 140 at the cut surface 140sa (or the cut surface 140sb) may be removed. Figure 3B FIG. 1 shows an example in which only a portion of the outer casing 140 with the cut surface 140sa removed. Figure 3B In the example shown, a portion of the surface of the outer casing 140 at the cut surface 140sa is removed in a groove shape to form a groove portion 140g. The width W2 of the groove portion 140g can be wider than the width W1 of the connection surface 211a, and can be formed to a width that the anode lead terminal 212 can enter. Specifically, the width W2 can be formed to be the same as the width of the anode lead terminal 212 or slightly larger than the width of the anode lead terminal 212. As a result, since a portion of the anode lead terminal 212 can be embedded in the groove portion 140g, the connection between the anode lead terminal 212 and the connection surface 211a becomes easy. In addition, the connection between the anode lead terminal 212 and the connection surface 211a is stable. In addition, the width of the anode lead terminal 212 is wider than the width of the connection surface 211a, and the anode lead terminal 212 covers the entire connection surface 211a.

[0111] Next, if Figure 1DAs shown, the anode lead terminal 212 is connected to the connection surface 211a of the anode connecting member 211 (step (iv)). Similarly, the cathode lead terminal 222 is connected to the connection surface 221a of the cathode connecting member 221. The anode lead terminal 212 and the cathode lead terminal 222 are respectively exposed to the outside. That is, they are exposed from the outer body 140. A portion of the anode lead terminal 212 and a portion of the cathode lead terminal 222 are arranged on the bottom surface 140b of the outer body 140. These portions can function as terminals when the manufactured solid electrolytic capacitor 10 is mounted on a printed circuit board, etc. The anode lead terminal 212 and the cathode lead terminal 222 can also be connected to the connection surface in a state of being processed into an L shape. Alternatively, the anode lead terminal 212 and the cathode lead terminal 222 can also be connected to the connection surface and then bent.

[0112] The anode lead portion 111a contains a valve metal, so a relatively stable natural oxide film is formed on the surface. Therefore, it is difficult to connect the anode lead terminal 212 to the anode lead portion 111a. In contrast, the connection between the anode lead terminal 212 and the anode connecting member 211 can be easily and reliably performed. Of course, when the anode lead terminal 212 and the anode connecting member 211 are connected, the anode lead terminal 212 and the anode lead portion 111a can also be connected. These descriptions also apply to the connection on the cathode portion 130 side.

[0113] As described above, solid electrolytic capacitor 10 is obtained. In solid electrolytic capacitor 10, connection surface 211a of anode connection member 211 is covered by anode lead terminal 212 but is exposed from exterior body 140. Similarly, connection surface 221a of cathode connection member 221 is covered by cathode lead terminal 222 but is exposed from exterior body 140.

[0114] In the above example, the cathode connecting member 221 side is also cut. However, the cathode connecting member 221 side may not be cut. In this case, the cathode connecting member is not cut and is used as the cathode lead terminal 231. Figure 4 An example of a solid electrolytic capacitor 10 in this case is schematically shown in FIG.

[0115] In the above-described manufacturing method, the anode connecting member 211 may be sandwiched between the ends of the plurality of stacked anode lead-out portions 111 a , and the cathode connecting member 221 may be sandwiched between the plurality of stacked cathode portions 130 . Figure 5A The state after completion of step (i) in this case is schematically shown in FIG. Figure 5B The solid electrolytic capacitor 10 obtained is schematically shown in FIG. Figure 5A as well as Figure 5BAs shown, the anode connection member 211 is sandwiched between the plurality of stacked anode lead-out portions 111 a , and the cathode connection member 221 is sandwiched between the plurality of stacked cathode portions 130 .

[0116] (Implementation method 2)

[0117] In Embodiment 2, a method for manufacturing another example of a solid electrolytic capacitor including a solid electrolytic capacitor element is described. The anode body of the solid electrolytic capacitor element used in Embodiment 2 is a sintered body. The solid electrolytic capacitor of Embodiment 2 includes one solid electrolytic capacitor element.

[0118] First, if Fig. 6A As shown, one solid electrolytic capacitor element 100 is connected to the anode connecting member 211 and the lead terminal 231 on the cathode side (step (i)). In addition, in Embodiment 2, an example in which only the anode connecting member 211 side is cut is described, but similarly to Embodiment 1, the cathode connecting member and the solid electrolytic capacitor element 100 may be connected, and both the anode connecting member 211 side and the cathode connecting member side may be cut. In this case, as described above, the connection surface of the cathode connecting member exposed by cutting is connected to the cathode lead terminal.

[0119] Figure 7 , a cross-sectional view of an example of a solid electrolytic capacitor element 100 is schematically shown. The solid electrolytic capacitor element 100 includes: an anode portion 110 including an anode body (sintered body) 111 and an anode lead portion (anode wire) 111a; a dielectric layer 120 covering at least a portion of the anode body 111; and a cathode portion 130 covering at least a portion of the dielectric layer 120. The cathode portion 130 includes: an electrolyte layer 131 covering at least a portion of the dielectric layer 120; and a conductive layer 132 formed on the electrolyte layer 131.

[0120] Conductive layer 132 is connected to cathode lead terminal 231 by metal paste or the like. One end of anode lead portion 111a is embedded in anode body 111. The other end of anode lead portion 111a is connected to anode connection member 211 by welding or the like.

[0121] Next, steps (ii) to (iv) are carried out in the same manner as in Embodiment 1 except that the cathode connecting member side is not cut. Figure 6B The solid electrolytic capacitor 10 is shown.

[0122] (Note)

[0123] The above description discloses the following technology.

[0124] (Technique 1)

[0125] A method for manufacturing a solid electrolytic capacitor, the solid electrolytic capacitor comprising at least one solid electrolytic capacitor element, the at least one solid electrolytic capacitor element comprising a cathode portion and an anode portion comprising an anode lead-out portion, the method for manufacturing the solid electrolytic capacitor comprising:

[0126] Step (i), connecting an anode connecting member made of a metal other than a valve metal to the anode lead-out portion of the at least one solid electrolytic capacitor element;

[0127] Step (ii), forming an outer casing so as to cover at least one solid electrolytic capacitor element and at least a portion of the anode connecting member;

[0128] (iii), removing a portion of the outer casing so that a portion of the surface of the anode connecting member is exposed from the outer casing as a connecting surface; and

[0129] The step (iv) is to connect an anode lead terminal to the connection surface of the anode connection member.

[0130] (Technique 2)

[0131] In the manufacturing method described in technology 1,

[0132] The solid electrolytic capacitor includes a plurality of stacked solid electrolytic capacitor elements.

[0133] In the step (i), the ends of the anode lead-out portions of the plurality of solid electrolytic capacitor elements are collectively connected to the anode connecting member.

[0134] (Technique 3)

[0135] In the manufacturing method described in technology 1 or 2,

[0136] The anode portion includes a sintered body containing a valve metal.

[0137] (Technique 4)

[0138] In the manufacturing method described in any one of techniques 1 to 3,

[0139] The step (iii) includes a step (iii-a) of removing the portion of the outer casing by cutting the outer casing and the anode connecting member together.

[0140] (Technique 5)

[0141] In the manufacturing method described in technique 4,

[0142] The step (iii) further includes, after the step (iii-a), a step (iii-b) of removing a portion of the outer casing exposed at the cut surface so that the portion of the anode connecting member protrudes from the outer casing.

[0143] (Technique 6)

[0144] In the manufacturing method described in any one of techniques 1 to 5,

[0145] The step (i) further includes the step of connecting a cathode connecting member made of a metal other than a valve metal to the cathode portion,

[0146] In the step (ii), the outer casing is formed so as to cover the at least one solid electrolytic capacitor element, at least a portion of the anode connecting member, and at least a portion of the cathode connecting member.

[0147] The step (iii) further includes the step of removing another portion of the outer casing to expose a portion of the surface of the cathode connecting member from the outer casing as a connecting surface.

[0148] The step (iv) further includes the step of connecting a cathode lead terminal to the connection surface of the cathode connection member.

[0149] (Technique 7)

[0150] A solid electrolytic capacitor, comprising:

[0151] At least 1 solid electrolytic capacitor element;

[0152] an anode connecting member composed of a metal other than valve metal;

[0153] an outer casing configured to cover the at least one solid electrolytic capacitor element and the anode connecting member; and

[0154] Anode lead terminal, exposed to the outside,

[0155] The solid electrolytic capacitor element comprises a cathode portion and an anode portion including an anode lead portion,

[0156] The anode connecting member is connected to the anode lead-out portion,

[0157] A portion of the surface of the anode connecting member is exposed from the outer casing as a connecting surface,

[0158] The connection surface of the anode connection member is connected to the anode lead terminal.

[0159] (Technique 8)

[0160] In the solid electrolytic capacitor described in Technology 7,

[0161] The solid electrolytic capacitor includes a plurality of stacked solid electrolytic capacitor elements.

[0162] Ends of the plurality of anode lead-out portions of the plurality of solid electrolytic capacitor elements are collectively connected to the anode connecting member.

[0163] (Technique 9)

[0164] In the solid electrolytic capacitor described in technology 7 or 8,

[0165] The anode portion includes a sintered body containing a valve metal.

[0166] (Technology 10)

[0167] In the solid electrolytic capacitor described in any one of Techniques 7 to 9,

[0168] The portion of the anode connecting member protrudes from the exterior body.

[0169] (Technology 11)

[0170] In the solid electrolytic capacitor described in any one of Techniques 7 to 10,

[0171] The solid electrolytic capacitor further comprises: a cathode connecting member covered by the outer casing and made of a metal other than a valve metal; and a cathode lead terminal exposed to the outside,

[0172] The cathode connecting member is connected to the cathode portion,

[0173] A portion of the surface of the cathode connecting member is exposed from the outer casing as a connecting surface,

[0174] The connection surface of the cathode connection member is connected to the cathode lead terminal.

[0175] Industrial Applicability

[0176] The present disclosure can be applied to solid electrolytic capacitors.

[0177] The present invention has been described with respect to the present preferred embodiments, but such disclosure should not be construed in a limiting sense. Various modifications and changes will be apparent to those skilled in the art of the art to which the present invention pertains upon reading the above disclosure. Therefore, the appended claims should be construed as including all modifications and changes without departing from the true spirit and scope of the present invention.

[0178] -Explanation of symbols-

[0179] 10: Solid electrolytic capacitor

[0180] 100: Solid electrolytic capacitor element

[0181] 110: Anode

[0182] 111: Anode

[0183] 111a: Anode lead-out portion

[0184] 130: Cathode

[0185] 140: Exterior body

[0186] 211: Anode connecting member

[0187] 211a: Connection surface

[0188] 212: Anode lead terminal

[0189] 221: Cathode connecting member

[0190] 221a: Connection surface

[0191] 222: Cathode lead terminal

[0192] 231: Lead terminal.

Claims

1. A method for manufacturing a solid electrolytic capacitor, the solid electrolytic capacitor comprising at least one solid electrolytic capacitor element, the at least one solid electrolytic capacitor element comprising a cathode portion and an anode portion comprising an anode lead portion, the method for manufacturing the solid electrolytic capacitor comprising: Step (i), connecting an anode connecting member made of a metal other than a valve metal to the anode lead-out portion of the at least one solid electrolytic capacitor element; Step (ii), forming an outer casing so as to cover at least one solid electrolytic capacitor element and at least a portion of the anode connecting member; (iii) removing a portion of the outer casing so that a portion of the surface of the anode connecting member is exposed from the outer casing as a connecting surface; and and step (iv) connecting an anode lead terminal to the connection surface of the anode connection member.

2. The manufacturing method according to claim 1, wherein: The solid electrolytic capacitor includes a plurality of stacked solid electrolytic capacitor elements. In the step (i), the ends of the anode lead-out portions of the plurality of solid electrolytic capacitor elements are collectively connected to the anode connecting member.

3. The manufacturing method according to claim 1, wherein: The anode portion includes a sintered body containing a valve metal.

4. The manufacturing method according to claim 1 or 2, wherein: The step (iii) includes a step (iii-a) of removing the portion of the outer casing by cutting the outer casing and the anode connecting member together.

5. The manufacturing method according to claim 4, wherein: The step (iii) further includes, after the step (iii-a), a step (iii-b) of removing a portion of the outer casing exposed at the cut surface so that the portion of the anode connecting member protrudes from the outer casing.

6. The manufacturing method according to claim 1, wherein: The step (i) further includes the step of connecting a cathode connecting member made of a metal other than a valve metal to the cathode portion, In the step (ii), the outer casing is formed so as to cover the at least one solid electrolytic capacitor element, at least a portion of the anode connecting member, and at least a portion of the cathode connecting member. The step (iii) further includes the step of removing another portion of the outer casing to expose a portion of the surface of the cathode connecting member from the outer casing as a connecting surface. The step (iv) further includes the step of connecting a cathode lead terminal to the connection surface of the cathode connection member.

7. A solid electrolytic capacitor comprising: At least 1 solid electrolytic capacitor element; an anode connecting member composed of a metal other than valve metal; an outer casing configured to cover the at least one solid electrolytic capacitor element and the anode connecting member; and Anode lead terminal, exposed to the outside, The solid electrolytic capacitor element comprises: a cathode portion and an anode portion including an anode lead portion, The anode connecting member is connected to the anode lead-out portion, A portion of the surface of the anode connecting member is exposed from the outer casing as a connecting surface, The connection surface of the anode connection member is connected to the anode lead terminal.

8. The solid electrolytic capacitor according to claim 7, wherein: The solid electrolytic capacitor includes a plurality of stacked solid electrolytic capacitor elements. Ends of the plurality of anode lead-out portions of the plurality of solid electrolytic capacitor elements are collectively connected to the anode connecting member.

9. The solid electrolytic capacitor according to claim 7, wherein: The anode portion includes a sintered body containing a valve metal.

10. The solid electrolytic capacitor according to claim 7 or 8, wherein: The portion of the anode connecting member protrudes from the exterior body.

11. The solid electrolytic capacitor according to claim 7 or 8, wherein: The solid electrolytic capacitor further comprises: a cathode connecting member covered by the outer casing and made of a metal other than a valve metal; and a cathode lead terminal exposed to the outside, The cathode connecting member is connected to the cathode portion, A portion of the surface of the cathode connecting member is exposed from the outer casing as a connecting surface, The connection surface of the cathode connection member is connected to the cathode lead terminal.

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