Capacitor assembly

Abstract

This capacitor assemply comprises a capacitor element, a first external packaging case, and a second external packaging case. One of the first external packaging case and the second external packaging case is an anode external packaging case that is provided with an anode terminal for electrically connecting with an anode section of the capacitor element, and is a bottomed tube shape in which one end section is open, and the other is a cathode external packaging case that is provided with a cathode terminal for electrically connecting with a cathode section of the capacitor element, and is a bottomed tube shape in which one end section is open. The open end section of the first external packaging case and the open end section of the second external packaging case are joined, unifying the anode external packaging case and the cathode external packaging case and storing the capacitor element.

Description

Capacitor Assembly

[0001] The present invention relates to a capacitor assembly, and more particularly to the structure of an exterior case that houses a capacitor element within the capacitor assembly.

[0002] Electrolytic capacitors have a low equivalent series resistance (ESR) and excellent frequency characteristics, and are therefore used in a variety of electronic devices.

[0003] As a method for housing an electrolytic capacitor in an outer case, Patent Document 1 describes a capacitor assembly including an electrolytic capacitor and a ceramic housing that houses the electrolytic capacitor. With the electrolytic capacitor positioned in the ceramic housing, a lid is positioned on the ceramic housing, and the lid is welded to a side wall of the ceramic housing in the presence of a gas atmosphere containing an inert gas, thereby obtaining a capacitor assembly.

[0004] JP 2009-253278 A

[0005] In Patent Document 1, in order to weld the lid to the side wall of the ceramic housing, the side wall must be sufficiently thick. This limits the size of the electrolytic capacitor that can be housed within the ceramic housing. In addition, space is required to electrically connect the anode of the electrolytic capacitor to the anode terminal provided outside the ceramic housing, which may leave excess space within the housing that is not occupied by the electrolytic capacitor. As a result, the mounting size of the electrolytic capacitor is limited, making it difficult to increase the capacitance.

[0006] In view of the above, one aspect of the present disclosure relates to a capacitor assembly including a capacitor element, a first outer case, and a second outer case, wherein one of the first outer case or the second outer case is a cylindrical anode outer case with a bottom and one end open and provided with an anode terminal that electrically connects to an anode portion of the capacitor element, and the other of the first outer case or the second outer case is a cylindrical cathode outer case with a bottom and one end open and provided with a cathode terminal that electrically connects to a cathode portion of the capacitor element, the open end of the first outer case and the open end of the second outer case are joined, and the anode outer case and the cathode outer case together house the capacitor element.

[0007] The dimensions of the capacitor element or electrolytic capacitor that can be housed in the exterior case can be increased, making it easy to realize a high-capacity electrolytic capacitor.

[0008] The novel features of the present invention are set forth in the appended claims, but the present invention, both in terms of structure and content, together with other objects and features of the present invention, will be better understood from the following detailed description taken in conjunction with the drawings.

[0009] FIG. 1 is a cross-sectional view schematically showing an example of a configuration of a capacitor assembly according to an embodiment of the present disclosure; FIG. 2 is a side view and a bottom view schematically showing an example of a configuration of a capacitor assembly according to an embodiment of the present disclosure; FIG. 3 is a bottom view showing an anode exterior case and a cathode exterior case used in the capacitor assembly according to an embodiment of the present disclosure in a separated state; FIG. 4 is a bottom view showing another example of a capacitor assembly according to an embodiment of the present disclosure in a separated state of the anode exterior case and the cathode exterior case; FIG. 5 is a bottom view showing yet another example of a capacitor assembly according to an embodiment of the present disclosure in a separated state of the anode exterior case and the cathode exterior case; FIG. 6 is a bottom view showing yet another example of a capacitor assembly according to an embodiment of the present disclosure in a separated state of the anode exterior case and the cathode exterior case; FIG. 7 is a top view of the interior of a capacitor assembly showing an embodiment of a capacitor assembly having a plurality of capacitor elements; FIG. 8 is a cross-sectional view of a capacitor assembly showing an embodiment of a capacitor assembly including an element stack in which a plurality of capacitor elements are stacked;

[0010] Hereinafter, embodiments of the present disclosure will be described using examples, but the present disclosure is not limited to the examples described below. In the following description, specific numerical values, materials, etc. may be exemplified, but other numerical values, materials, etc. may be applied as long as the effects of the present disclosure are obtained. In this specification, the expression "numerical value A to numerical value B" includes numerical value A and numerical value B and can be read as "numerical value A or more and numerical value B or less." In the following description, when lower and upper limits of numerical values ​​related to specific physical properties or conditions are exemplified, any of the exemplified lower limits and any of the exemplified upper limits can be arbitrarily combined, as long as the lower limit is not equal to or greater than the upper limit. When multiple materials are exemplified, one of the materials may be selected and used alone, or two or more of the materials may be used in combination.

[0011] The present disclosure also encompasses combinations of two or more features arbitrarily selected from the appended claims, i.e., two or more features arbitrarily selected from the appended claims can be combined unless a technical contradiction arises.

[0012] A capacitor assembly according to an embodiment of the present disclosure includes a capacitor element, a first outer case, and a second outer case. One of the first outer case and the second outer case is a cylindrical anode outer case with one open end and an anode terminal electrically connected to the anode portion of the capacitor element, and the other of the first outer case and the second outer case is a cylindrical cathode outer case with one open end and an anode terminal electrically connected to the cathode portion of the capacitor element. In the capacitor assembly, the open end of the first outer case and the open end of the second outer case are joined, and the anode outer case and the cathode outer case are integrated to house the capacitor element. The shape of the integrated outer case of the anode outer case and the cathode outer case is, for example, a substantially rectangular parallelepiped. In the following description, the first outer case is the anode outer case and the second outer case is the cathode outer case. However, the present invention is not limited thereto, and the first outer case may be the cathode outer case and the second outer case may be the anode outer case.

[0013] According to this capacitor assembly, by joining the open ends of the first outer case and the second outer case together, a joint is formed on the outer surface of each outer case, so that the mounting dimensions of the capacitor element are not affected by the joint, and the mounting dimensions of the capacitor element can be increased.

[0014] For example, a first joint portion where a metal material is exposed may be provided on the outer surface of the open end of the first outer case. Similarly, a second joint portion where a metal material is exposed may be provided on the outer surface of the open end of the second outer case. By joining the first joint portion and the second joint portion, the two outer cases can be easily joined while ensuring strength. Examples of metal materials include solder, copper, gold, iron, nickel, iron-nickel alloys, etc. The metal material may be fixed to a ceramic substrate, for example, by a gas-phase method such as vapor deposition or a liquid-phase method such as electroless plating. The first joint portion and the second joint portion are joined by, for example, soldering or welding.

[0015] It is preferable that the outer surface of the first outer case at the first joint where the metal material is exposed is flush with the outer surface of the second outer case at the second joint where the metal material is exposed, which makes it possible to easily join the first and second joints.

[0016] The anode terminal may be provided on the bottom of the anode outer case (either the first outer case or the second outer case). The cathode terminal may be provided on the bottom of the cathode outer case (the other of the first outer case or the second outer case). In this case, the anode terminal and the cathode terminal are arranged in opposing positions across the cylindrical portion of the outer case. In this case, the structure for electrically connecting the capacitor element to the anode terminal and the cathode terminal can be made compact, and the dimensions of the capacitor element relative to the outer case can be maximized. In addition, since the terminal arrangement is similar to that of conventional chip-type capacitors, it is easy to mount on a printed circuit board. Here, the "bottom" refers to the closed portion on the opposite side of the opening of the bottomed cylindrical case.

[0017] For example, in the case of a capacitor element provided with an anode body and an anode wire embedded in the anode body, the anode terminal can be disposed opposite the embedded surface of the anode wire and on an extension of the anode wire extending from the embedded surface. The cathode terminal can be disposed, for example, at a position facing the surface of the anode body opposite the embedded surface of the anode wire.

[0018] To facilitate fastening the first outer case and the second outer case, the second outer case may be provided with a fitting portion that protrudes from the open end toward the open end. The fitting portion is inserted into the inside of the open end of the first outer case to fasten the first outer case and the second outer case. The fitting portion allows the first outer case and the second outer case to be temporarily fastened together, and welding or the like can be performed in the temporarily fastened state to facilitate joining the first joint portion and the second joint portion.

[0019] To facilitate insertion of the fitting portion, the outer diameter of the fitting portion may be smaller than the outer diameter of the open end of the first outer case. In this case, the outer surface of the fitting portion may be flush with the outer surface of the second outer case excluding the joint portion and the fitting portion. In other words, the outer diameter of the tubular portion of the second outer case may be made smaller at least in a portion on the open end side, and the portion of the tubular portion with the smaller outer diameter may serve as the fitting portion.

[0020] A protrusion may be provided on the inner surface of the opening end of the first outer case to regulate the insertion position of the fitting portion inserted into the first outer case, which makes it easier to position the first outer case and the second outer case and to temporarily fasten them together.

[0021] The first and second outer cases may be filled with a gas for the purpose of suppressing deterioration in the characteristics of the capacitor element. The gas may be an inert gas. Examples of inert gases include nitrogen gas, argon gas, and helium gas. A heat dissipation member may be enclosed in the first and second outer cases. The heat dissipation member has excellent thermal conductivity and quickly dissipates heat generated in the capacitor element (electrolytic capacitor), suppressing a temperature rise in the capacitor element (electrolytic capacitor). The heat dissipation member may be a heat dissipation sheet. Examples of materials for the heat dissipation member or heat dissipation sheet include silicone rubber containing a thermally conductive filler.

[0022] The anode exterior case and / or the cathode exterior case may include a ceramic housing and a metal material adhered to a predetermined area on the surface of the housing. In this case, the anode terminal and / or the cathode terminal may be formed of the metal material adhered to the outer surface of the anode exterior case or the cathode exterior case.

[0023] Similarly, an exposed metal region where the metal material is exposed can be formed on the inner surface of the anode exterior case and / or the cathode exterior case. The exposed metal region on the inner surface of the anode exterior case is electrically connected to the anode terminal, and the anode portion of the capacitor element can be electrically connected to the anode terminal via the exposed metal region. Alternatively, the exposed metal region on the inner surface of the cathode exterior case is electrically connected to the cathode terminal, and the cathode portion of the capacitor element can be electrically connected to the cathode terminal via the exposed metal region. The connection between the exposed metal region on the inner surface of each exterior case and the anode or cathode terminal on the outer surface may be made, for example, by penetrating the interior of the housing where the anode or cathode terminal is provided, and electrically connecting to the metal material exposed on the inner surface of the case.

[0024] An anode outer case and a cathode outer case, each having a hole (third joint) in the anode terminal or the cathode terminal, may be joined at the first joint and the second joint to form an integrated outer case having a hole, and then the third joint may be joined by a laser, soldering, welding, or the like, thereby electrically connecting the capacitor element to the anode terminal and the cathode terminal and sealing the outer case.

[0025] One of the anode exterior case or the cathode exterior case may comprise a metal housing. The other of the anode exterior case or the cathode exterior case comprises a ceramic housing and a metal material fixed to a predetermined region of the surface of the housing. By using a metal housing as one of the exterior cases, the amount of expensive ceramic material used can be reduced. Furthermore, the metal housing does not require the formation of a first joint or a second joint, and can be manufactured inexpensively. The inner surface of the metal housing may be covered with an insulating material.

[0026] The capacitor assembly may include a plurality of capacitor elements, each of which may be electrically connected in parallel to an anode terminal and a cathode terminal, and the capacitor assembly may include an element stack in which the plurality of capacitor elements are stacked.

[0027] The capacitor assembly according to this embodiment will be described below with reference to the accompanying drawings as appropriate. However, the present invention is not limited thereto. FIG. 1A is a cross-sectional view schematically showing an example of a capacitor assembly according to this embodiment. FIG. 1B is a bottom view and a side view of the capacitor assembly shown in FIG. 1A. FIG. 1B(a) is a side view taken along the main surface S3 of FIG. 1A. FIG. 1B(b) is a bottom view taken along the main surface S1 of FIG. 1A. FIG. 1B(c) is a side view taken along the main surface S4 of FIG. 1A. Note that in FIG. 1A, the thickness of the exterior case is depicted as being thicker than it actually is for the sake of explanation.

[0028] FIG. 2 is a bottom view of the anode outer case 40A and the cathode outer case 40B in a separated state before the capacitor element 10 is housed, as viewed from the surface S1 side of FIG. 1A.

[0029] The capacitor assembly 100 includes a capacitor element 10, an anode outer case (first outer case) 40A, and a cathode outer case (second outer case) 40B.

[0030] The anode outer case 40A and the cathode outer case 40B are each a cylindrical outer case with one end open and a bottom, and the other end of the anode outer case 40A and the cathode outer case 40B is closed by a bottom.

[0031] The anode exterior case 40A has a ceramic housing 41A, and a metal material 42A is fixed to a predetermined region of the housing 41A by vapor deposition, using the housing 41A as a base layer. The vapor-deposited metal material 42A forms an anode terminal 43A, a joint (first joint) 44A, and an exposed region 45A.

[0032] Like the anode case 40A, the cathode case 40B has a ceramic housing 41B, and a metal material 42B is fixed to a predetermined region of the housing 41B by vapor deposition, using the housing 41B as a base layer. The vapor-deposited metal material 42B forms a cathode terminal 43B, a joint (second joint) 44B, and an exposed region 45B.

[0033] The first bonding portion 44A and the second bonding portion 44B are provided on the outer surfaces of the open ends of the anode outer case 40A and the cathode outer case 40B, respectively. By bonding the first bonding portion 44A to the second bonding portion 44B, one open end of each outer case is closed by the other, and the anode outer case 40A and the cathode outer case 40B form an integrated outer case as a whole. The anode outer case 40A and the cathode outer case 40B are integrated and house the capacitor element 10.

[0034] The outer surface of the anode outer case 40A at the first joint portion 44A is flush with the outer surface of the cathode outer case 40B at the second joint portion 44B, forming a flat joint surface, which makes it easy to form the joint and increases the joint strength.

[0035] In an outer case in which the anode outer case 40A and the cathode outer case 40B are joined together to form an integrated case, the positions of the first joint portion 44A and the second joint portion 44B may be located at the center of the integrated outer case or may be located off to the bottom side of the anode outer case 40A or the cathode outer case 40B, and are not particularly limited.

[0036] The anode terminal 43A is provided on the outer surface of the bottom of the anode exterior case 40A. An exposed area 45A is provided on the inner surface of the bottom of the anode exterior case 40A, located behind the anode terminal 43A. A through-hole 46A is provided in the housing 41A at the bottom of the anode exterior case 40A, and the through-hole 46A is filled with a metal material. The exposed area 45A is electrically connected to the anode terminal 43A via the through-hole 46A.

[0037] The exposed region 45A is electrically connected to the anode portion 6 of the capacitor element, whereby the anode terminal 43A is electrically connected to the anode portion 6.

[0038] Similarly, a cathode terminal 43B is provided on the outer surface of the bottom of the cathode exterior case 40B. An exposed region 45B is provided on the inner surface of the bottom of the cathode exterior case 40B, located behind the cathode terminal 43B. A through-hole 46B is provided in the housing 41B at the bottom of the cathode exterior case 40B, and the through-hole 46B is filled with a metal material. The exposed region 45B is electrically connected to the cathode terminal 43B via the through-hole 46B.

[0039] The exposed region 45B is electrically connected to the cathode portion 7 of the capacitor element, whereby the cathode terminal 43B is electrically connected to the cathode portion 7.

[0040] An exposed area to which a metal material is fixed using the housing as a base layer may also be provided on the back surface of the first bonding portion 44A and / or the second bonding portion 44B, and the exposed area may be electrically connected to the first bonding portion 44A and the second bonding portion 44B. In this case, the first bonding portion 44A and the second bonding portion 44B function as an anode terminal or a cathode terminal (e.g., a cathode terminal).

[0041] Either the anode outer case 40A or the cathode outer case 40B may be an outer case in which a metal material is fixed to a predetermined region of a ceramic housing by vapor deposition, and the other may be a cylindrical case made of metal and with a bottom.

[0042] The anode outer case 40A and the cathode outer case 40B may be integrated into one outer case, and a specific gas may be filled in the integrated outer case. The gas may be, for example, an inert gas. A heat dissipation member (for example, a heat dissipation sheet) may be enclosed in the integrated outer case.

[0043] Capacitor element 10 has an anode portion 6 and a cathode portion 7. Anode portion 6 is electrically connected to anode terminal 43A, and cathode portion 7 is electrically connected to cathode terminal 43B, respectively, to form capacitor assembly 100. In the example of FIG. 1 , anode portion 6 has anode body 1 and anode wire 2. An implanted portion 2b of anode wire 2 extending from anode body 1 is joined to exposed region 45A, thereby electrically connecting anode portion 6 to anode terminal 43A via anode wire 2. Anode body 1 is a porous sintered body of a valve metal, and a dielectric layer 3 is formed on the surface of anode body 1. Cathode portion 7 has solid electrolyte layer 4 covering at least a portion of dielectric layer 3 and cathode layer 5 covering at least a portion of the surface of solid electrolyte layer 4. Cathode layer 5 is adhesively fixed to exposed region 45A via conductive adhesive 8, thereby electrically connecting cathode portion 7 to cathode terminal 43B.

[0044] When the anode wire 2 is joined to the exposed region 45A by laser welding, a hole may be provided in the bottom of the anode exterior case 40A to facilitate welding, and the third joining portion 53 may be formed in the hole.

[0045] The configuration of the capacitor element is not limited thereto, and for example, a valve metal foil may be used as the anode body 1. At least a partial region of the valve metal foil may be roughened by, for example, etching, and a dielectric layer 3 may be formed on the surface of the roughened region. At least a portion of the dielectric layer 3 is covered with a cathode portion 7. A partial region of the surface of the valve metal foil is not covered with the cathode portion 7, and the portion of the anode body 1 not covered with the cathode portion 7 is adhesively fixed to the exposed region 45A via a conductive adhesive, thereby electrically connecting the anode portion 6 and the anode terminal 43A. A laminate of valve metal foils on which the cathode portion 7 is formed may be used as the anode body 1.

[0046] Fig. 3 shows another embodiment of the anode exterior case 40A and the cathode exterior case 40B. Fig. 3 is a bottom view of the anode exterior case 40A1 and the cathode exterior case 40B1 in a separated state. One of the anode exterior case 40A1 and the cathode exterior case 40B1 (here, the cathode exterior case 40B1) is provided with a fitting portion 47 that protrudes from the open end of the exterior case toward the open end. The fitting portion 47 protrudes toward the open end on a side closer to the open end than the joint portion (here, the second joint portion 44B).

[0047] The fitting portion 47 is inserted into the inside of the open end of the other of the anode exterior case 40A1 and the cathode exterior case 40B1 (here, the cathode exterior case 40B1). By inserting the fitting portion 47, the anode exterior case 40A1 and the cathode exterior case 40B1 are temporarily fixed in an integrated state. Since the first bonding portion 44A and the second bonding portion 44B can be bonded in the temporarily fixed state, the first bonding portion and the second bonding portion can be easily bonded.

[0048] The fitting portion 47 is inserted into the cathode outer case 40B1 until the first bonding portion 44A and the second bonding portion 44B are adjacent to or overlap each other.

[0049] To facilitate the insertion of the fitting portion 47, as shown in FIG. 3, the outer diameter of the tube at the fitting portion 47 may be formed smaller than the outer diameter of the open end of the other of the anode outer case 40A1 and the cathode outer case 40B1 (here, the anode outer case 40A1 into which the fitting portion 47 is inserted).

[0050] Fig. 4 shows yet another embodiment of the anode exterior case 40A and the cathode exterior case 40B. Fig. 4 is a bottom view of the anode exterior case 40A2 and the cathode exterior case 40B2 in a separated state. In the example of Fig. 4, a protrusion 48 that protrudes toward the inside of the cylinder is provided on the inner surface of the open end of the anode exterior case 40A2, into which the fitting portion 47 is inserted. The other configurations are similar to those of the anode exterior case 40A1 and the cathode exterior case 40B1 shown in Fig. 3.

[0051] The protrusion 48 is, for example, a recess formed in a predetermined region of the housing of the anode exterior case 40A2 and protruding toward the inside of the cylinder. The protrusion 48 regulates the insertion position when the fitting portion 47 of the cathode exterior case 40B2 is inserted into the open end of the anode exterior case 40A2, making it easy to position the cathode exterior case 40B2 relative to the anode exterior case 40A2.

[0052] 5 shows yet another embodiment of the anode exterior case 40A and the cathode exterior case 40B. FIG. 5 is a bottom view showing the anode exterior case 40A3 and the cathode exterior case 40B3 in a separated state. As shown in FIG. 5, the outer diameter of the cylindrical portion of one of the anode exterior case 40A3 and the cathode exterior case 40B3 (here, the cathode exterior case 40B3 on which the fitting portion 47 is provided) may be smaller than the outer diameter of the cylindrical portion of the other (here, the anode exterior case 40A3 on which the fitting portion 47 is inserted). In this case, the outer surface of the fitting portion 47 may be flush with the outer surface of the cylindrical portion of the cathode exterior case 40B3 in a portion excluding the second joint portion 44B and the fitting portion 47 (for example, the exposed portion of the housing 41B).

[0053] In the above example, the fitting portion 47 is provided on the cathode outer case 40B1 to 40B3. The protrusion 48 is provided on the anode outer case 40A2. However, the present invention is not limited to this, and the fitting portion 47 may be provided on the anode outer case and the protrusion 48 may be provided on the cathode outer case.

[0054] FIG. 6 shows yet another embodiment of the anode exterior case 40A and the cathode exterior case 40B. FIG. 6 is a bottom view of the anode exterior case 40A4 and the cathode exterior case 40B4 in a separated state. In this example, the anode exterior case 40A4 is a cylindrical metal case with a bottom and an opening, and the entire surface of the metal case can form the anode terminal 43A. The end of the metal case on the opening side forms the first joint portion 44A. Like the cathode exterior cases 40B and 40B1 to 40B3, the cathode exterior case 40B4 is an exterior case in which a metal material is vapor-deposited in a predetermined region of a ceramic housing 41B, and the cathode terminal 43B and the second joint portion 44B are formed.

[0055] A plurality of capacitor elements may be housed in the capacitor assembly. The plurality of capacitor elements may be mounted on a substrate, for example, with the anode portions of the respective capacitor elements electrically connected to an anode terminal and the cathode portions of the respective capacitor elements electrically connected to a cathode terminal. The plurality of capacitor elements may be stacked such that the cathode portions of the respective capacitor elements overlap each other to form an element stack.

[0056] FIG. 7 shows an example of a capacitor assembly 101 in which eight capacitor elements 10a to 10h are mounted on a substrate. FIG. 7 is a top view of the interior of the capacitor assembly (as viewed from the main surface S2 side of FIG. 1A). Wiring layers are formed on the surface of the substrate 50 facing the capacitor elements 10a to 10h and on the opposite surface, and the wiring layers on both surfaces are electrically connected via through holes. Each of the anode portions of the capacitor elements 10a to 10h is electrically connected to an anode terminal 43A via a connecting member 51A and a conductive adhesive 8 provided at the end of the substrate 50 on the anode outer case 40A side. Each of the cathode portions of the capacitor elements 10a to 10e is electrically connected to a cathode terminal 43B via a connecting member 51B and a conductive adhesive 8 provided at the end of the substrate 50 on the cathode outer case 40B side, thereby forming the capacitor assembly 101. A structure in which multiple substrates are stacked in multiple stages may also be used.

[0057] 8 is a cross-sectional view showing an example of a capacitor assembly 102 including an element stack in which five capacitor elements 10a to 10e are stacked. The anode portions of the five stacked capacitor elements 10a to 10e are bundled together on the anode outer case 40A side and electrically connected to the anode terminal 43A via a connecting member 52. The cathode portions of the capacitor elements 10a to 10e are bundled together on the cathode outer case 40B side and electrically connected to the cathode terminal 43B via a connecting member. <Capacitor Elements>

[0058] Hereinafter, capacitor element 10 will be described in detail, taking as an example a case where a solid electrolyte layer is provided as the electrolyte.

[0059] The anode part 6 includes an anode body 1 and an anode wire 2 extending from one surface of the anode body 1 and electrically connecting to an anode terminal. The anode body 1 is, for example, a rectangular porous sintered body obtained by sintering metal particles. The metal particles are particles of a valve metal such as titanium (Ti), tantalum (Ta), or niobium (Nb). The anode body 1 includes one or more types of metal particles. The metal particles may be an alloy of two or more metals. For example, an alloy containing a valve metal and silicon, vanadium, boron, or the like may be used. Alternatively, a compound containing a valve metal and a typical element such as nitrogen may be used. The valve metal alloy contains a valve metal as the main component, for example, at least 50 atomic % of the valve metal.

[0060] The anode wire 2 is made of a conductive material. The material of the anode wire 2 is not particularly limited and includes, for example, copper, aluminum, aluminum alloys, and the like, in addition to the valve metals described above. The anode body 1 and the anode wire 2 may be made of the same material or different materials. The anode wire 2 has a first portion 2a that is embedded inside the anode body 1 from one surface of the anode body 1, and a second portion 2b that extends from the above surface of the anode body 1. The cross-sectional shape of the anode wire 2 is not particularly limited and includes, for example, a circle, a track shape (a shape consisting of parallel straight lines and two curves connecting the ends of these straight lines), an ellipse, a rectangle, a polygon, and the like.

[0061] The anode part 6 is fabricated, for example, by press-molding the first portion 2a into a rectangular parallelepiped shape while the first portion 2a is embedded in a powder of particles of the first metal, followed by sintering. This results in the second portion 2b of the anode wire 2 extending from one surface of the anode body 1 in an upright position. The second portion 2b is joined to the exposed region 45A of the anode exterior case 40A by welding or the like, thereby electrically connecting the anode wire 2 and the anode terminal 13. The welding method is not particularly limited, and examples include resistance welding and laser welding.

[0062] A dielectric layer 3 is formed on the surface of the anode body 1. The dielectric layer 3 is made of, for example, a metal oxide. Methods for forming a layer containing a metal oxide on the surface of the anode body 1 include, for example, a method of immersing the anode body 1 in a chemical conversion solution to anodize the surface of the anode body 1, and a method of heating the anode body 1 in an oxygen-containing atmosphere. The dielectric layer 3 is not limited to the above-mentioned layer containing a metal oxide, and may be any layer that is insulating.

[0063] (Cathode Section) The cathode section 7 has a solid electrolyte layer 4 and a cathode layer 5 covering the solid electrolyte layer 4. The solid electrolyte layer 4 is formed so as to cover at least a portion of the dielectric layer 3.

[0064] For example, a manganese compound or a conductive polymer is used for the solid electrolyte layer 4. Examples of conductive polymers include polypyrrole, polythiophene, polyfuran, polyaniline, and polyacetylene. These may be used alone or in combination. The conductive polymer may also be a copolymer of two or more monomers. In terms of excellent conductivity, polythiophene, polyaniline, and polypyrrole may be used. In particular, in terms of excellent water repellency, polypyrrole may be used.

[0065] The solid electrolyte layer 4 containing the conductive polymer may be composed of two or more solid electrolyte layers. For example, the solid electrolyte layer 4 may include a first conductive polymer layer covering the dielectric layer 3 and a second conductive polymer layer covering the first conductive polymer layer. When the solid electrolyte layer 4 is composed of two or more layers, the conductive polymers used in each layer may have different compositions or formation methods (polymerization methods). For example, the first conductive polymer layer may be formed by polymerizing a raw material monomer on the dielectric layer 3. Alternatively, the second conductive polymer layer may be formed by applying a liquid containing the conductive polymer to the dielectric layer 3.

[0066] In this specification, polypyrrole, polythiophene, polyfuran, polyaniline, etc. refer to polymers having polypyrrole, polythiophene, polyfuran, polyaniline, etc. as their basic skeletons, respectively. Therefore, polypyrrole, polythiophene, polyfuran, polyaniline, etc. may also include their respective derivatives. For example, polythiophene includes poly(3,4-ethylenedioxythiophene).

[0067] Various dopants may be added to the polymerization liquid for forming the conductive polymer, or the solution or dispersion of the conductive polymer in order to improve the conductivity of the conductive polymer. The dopant is not particularly limited, but examples thereof include naphthalenesulfonic acid, p-toluenesulfonic acid, and polystyrenesulfonic acid.

[0068] When the conductive polymer is dispersed in the dispersion medium in the form of particles, the average particle size D50 of the particles is, for example, 0.01 μm or more and 0.5 μm or less. If the average particle size D50 of the particles is in this range, the particles can easily penetrate into the interior of the anode body 1.

[0069] The cathode layer 5 has, for example, a carbon layer 5a formed to cover the solid electrolyte layer 4 and a metal paste layer 5b formed on the surface of the carbon layer 5a. The carbon layer 5a contains a conductive carbon material such as graphite and a resin. The metal paste layer 5b contains, for example, metal particles (e.g., silver) and a resin. The configuration of the cathode layer 5 is not limited to this configuration. The configuration of the cathode layer 5 may be any configuration that has a current collecting function.

[0070] While the present invention has been described in terms of presently preferred embodiments, such disclosure is not to be interpreted as limiting. Various changes and modifications will no doubt become apparent to those skilled in the art to which the present invention pertains upon reading the above disclosure. It is therefore intended that the appended claims be interpreted to cover all changes and modifications that do not depart from the true spirit and scope of the invention.

[0071] The present invention can be used in electrolytic capacitors, and preferably in electrolytic capacitors that use a porous body as an anode body.

[0072] 100, 101, 102: capacitor assembly 10a to 10h: capacitor element 1: anode body 2: anode wire 2a: first portion 2b: second portion 3: dielectric layer 4: solid electrolyte layer 5: cathode layer 5a: carbon layer 5b: metal paste layer 6: anode portion 7: cathode portion 8: conductive adhesive 40A, 40A1 to 40A3: anode exterior case 41A: housing 42A: metal material 43A: anode terminal 44A: joint portion (first joint portion) 45A: exposed area 46A: through hole 40B, 40B1 to 40B4: cathode exterior case 41B: housing 42B: metal material 43B: cathode terminal 44B: joint portion (second joint portion) 45B: exposed area 46B: through hole 47: fitting portion 48: protrusion 50: Substrate 51A, 51B, 52: Connection member 53: Hole portion (third joint portion)

Claims

1. a capacitor element; a first outer case; a second outer case; one of the first outer case and the second outer case is an anode outer case having a cylindrical shape with a bottom and one end open, and provided with an anode terminal electrically connected to an anode portion of the capacitor element; the other of the first outer case and the second outer case is a cylindrical cathode outer case having a bottom and one open end and provided with a cathode terminal electrically connected to a cathode portion of the capacitor element, a capacitor assembly in which the open end of the first outer case and the open end of the second outer case are joined together, and the anode outer case and the cathode outer case are integrated to house the capacitor element.

2. a first bonding portion where a metal material is exposed is provided on an outer surface of the open end of the first outer case; a second bonding portion where a metal material is exposed is provided on an outer surface of the open end of the second exterior case; The capacitor assembly of claim 1 , wherein the first joint portion is joined to the second joint portion.

3. The capacitor assembly according to claim 2 , wherein the outer surface of the first outer case at the first joint is flush with the outer surface of the second outer case at the second joint.

4. The capacitor assembly according to claim 2 , wherein the first joint portion is joined to the second joint portion by soldering or welding.

5. The capacitor assembly of claim 2 , wherein the metallic material in at least one of the first and second joints is bonded to a ceramic substrate.

6. the anode terminal is provided on the bottom of the anode exterior case, 6. The capacitor assembly according to claim 1, wherein the cathode terminal is provided at a bottom of the cathode exterior case.

7. The second exterior case is provided with a fitting portion that protrudes from the opening end toward the opening end side, 6. The capacitor assembly according to claim 1, wherein the fitting portion is inserted into the inside of the open end of the first outer case, thereby fixing the first outer case and the second outer case together.

8. The capacitor assembly according to claim 7 , wherein the fitting portion has an outer diameter smaller than the outer diameter of the open end of the first exterior case.

9. The capacitor assembly according to claim 8 , wherein an outer surface of the fitting portion is flush with an outer surface of the second exterior case excluding the joint portion and the fitting portion.

10. The capacitor assembly according to claim 7 , wherein a protrusion for regulating the position of the fitting portion is provided on the inner surface of the opening end of the first outer case.

11. 6. The capacitor assembly according to claim 1, wherein the first outer case and the second outer case are filled with an inert gas.

12. 6. The capacitor assembly according to claim 1, wherein a heat dissipation member is enclosed within the first outer case and the second outer case.

13. The capacitor assembly according to any one of claims 1 to 5, wherein the anode exterior case and the cathode exterior case each comprise a ceramic housing and a metal material adhered to a predetermined area of ​​a surface of the housing.

14. one of the anode exterior case and the cathode exterior case has a metal housing; The capacitor assembly according to any one of claims 1 to 5, wherein the other of the anode exterior case and the cathode exterior case comprises a ceramic housing and a metal material adhered to a predetermined area of ​​the surface of the housing.

15. at least one of the anode terminal and the cathode terminal is formed of a metal material fixed to an outer surface of the anode outer case or the cathode outer case, an exposed metal region in which the metal material is exposed is provided on an inner surface of at least one of the anode exterior case and the cathode exterior case; 14. The capacitor assembly according to claim 13, wherein the exposed metal area on the inner surface of the anode exterior case is electrically connected to the anode terminal, or the exposed metal area on the inner surface of the cathode exterior case is electrically connected to the cathode terminal.

16. a plurality of the capacitor elements; 6. The capacitor assembly according to claim 1, wherein each of the plurality of capacitor elements is electrically connected to the anode terminal and the cathode terminal in parallel with one another.

17. The capacitor assembly according to claim 16 , comprising an element stack in which the plurality of capacitor elements are stacked.