Solid electrolytic capacitor

Abstract

This solid electrolytic capacitor is provided with: at least one capacitor element having a positive electrode part and a negative electrode part; a positive electrode terminal electrically connected to the positive electrode part; a negative electrode terminal electrically connected to the negative electrode part; and an exterior resin that covers the capacitor element, the positive electrode terminal, and the negative electrode terminal in a state in which a portion of the positive electrode terminal and a portion of the negative electrode terminal are exposed. The exterior resin has a mounting surface, and four side-surfaces intersecting the mounting surface. By use of a solid electrolytic capacitor having hollow parts open to a side opposite to the exterior resin at sections that are of the positive electrode terminal and the negative electrode terminal and that are exposed along the mounting surface, it is possible to provide a solid electrolytic capacitor having improved quality of substrate mounting through soldering.

Description

solid electrolytic capacitor

[0001] The present disclosure relates to solid electrolytic capacitors.

[0002] Conventionally, a solid electrolytic capacitor has been known that includes a capacitor element having an anode portion and a cathode portion, an anode terminal electrically connected to the anode portion, a cathode terminal electrically connected to the cathode portion, and an exterior resin that covers these (see, for example, Patent Document 1). As shown in Figure 2 of Patent Document 1, the solid electrolytic capacitor of Patent Document 1 has a notch hole in each of the anode terminal and the cathode terminal, and the exterior resin has a protrusion that fits into the notch hole.

[0003] Japanese Patent Application Publication No. 9-92575

[0004] One aspect of the present disclosure relates to a solid electrolytic capacitor including at least one capacitor element having an anode portion and a cathode portion, an anode terminal electrically connected to the anode portion, a cathode terminal electrically connected to the cathode portion, and an exterior resin covering the capacitor element, the anode terminal, and the cathode terminal in a state in which a portion of each of the anode terminal and the cathode terminal is exposed, the exterior resin having a mounting surface and four side surfaces intersecting the mounting surface, and a hollow portion opening toward a side opposite the exterior resin is formed in the exposed portions of the anode terminal and the cathode terminal along the mounting surface.

[0005] According to the present disclosure, the quality of board mounting by soldering can be improved.

[0006] 1A and 1B are diagrams illustrating a solid electrolytic capacitor according to a first embodiment of the present disclosure, where (a) is a cross-sectional view and (b) is a bottom view, and (b) is a diagram illustrating a solid electrolytic capacitor according to a second embodiment of the present disclosure, where (a) is a cross-sectional view and (b) is a bottom view.

[0007] Before describing the embodiments, the problems in the prior art will be briefly described below.

[0008] Solid electrolytic capacitors are typically mounted on a substrate by soldering. However, if a large amount of solder is used, for example, the molten solder may flow around the anode terminal or cathode terminal, causing the solid electrolytic capacitor to tilt or lift. Thus, when a solid electrolytic capacitor is mounted on a substrate by soldering, the mounting quality may be impaired. In view of the above-mentioned problems, one of the objectives of the present disclosure is to improve the quality of substrate mounting by soldering.

[0009] The following describes an embodiment of a solid electrolytic capacitor according to the present disclosure. However, the present disclosure is not limited to the examples described below. While the following description may use specific numerical values ​​and materials, other numerical values ​​and materials may be used as long as the effects of the present disclosure are obtained.

[0010] A solid electrolytic capacitor according to the present disclosure includes at least one capacitor element, an anode terminal, a cathode terminal, and an exterior resin.

[0011] At least one capacitor element has an anode portion and a cathode portion. The anode portion may include an anode body and an anode wire. The anode body may be a porous sintered body obtained by sintering particles of a valve metal or the like. The anode wire may be made of a conductive wire. The cathode portion may include a solid electrolyte layer covering at least a portion of a dielectric layer formed on the surface of the anode body, and a cathode layer covering at least a portion of the solid electrolyte layer.

[0012] The anode terminal is electrically connected to the anode unit. The anode terminal may be made of a conductive material (e.g., metal) and may be bonded to an anode wire included in the anode unit.

[0013] The cathode terminal is electrically connected to the cathode part. The cathode terminal may be made of a conductive material (e.g., metal). The cathode terminal may be bonded to the cathode layer of the cathode part via, for example, a conductive adhesive.

[0014] The exterior resin covers the capacitor element, the anode terminal, and the cathode terminal in a state in which each of the anode terminal and the cathode terminal is partially exposed. The exterior resin may be composed of an insulating resin containing a filler. The exterior resin has a mounting surface and four side surfaces that intersect with the mounting surface. The mounting surface is the surface of the exterior resin that faces a member (such as a circuit board) on which the solid electrolytic capacitor is mounted. The exposed portion of the anode terminal functions as an external anode terminal of the solid electrolytic capacitor. The exposed portion of the cathode terminal functions as an external cathode terminal of the solid electrolytic capacitor.

[0015] The exposed portions of the anode and cathode terminals along the mounting surface (hereinafter also referred to as "first portions") have hollow portions that open toward the side opposite the exterior resin (i.e., toward the circuit board, etc.) (in other words, toward the outside of the solid electrolytic capacitor). The hollow portions define a space between the first portions and a component (such as a circuit board) to which the first portions are connected. The hollow portions may be closed at their peripheries within the first portions. Alternatively, the hollow portions may extend along the outer edge of the first portions. When the hollow portions extend along the outer edge of the first portions, the hollow portions are said to open toward another direction in addition to the side opposite the exterior resin (i.e., toward the circuit board, etc.). The other direction may be toward the center (or inside) of the solid electrolytic capacitor or the opposite side (or outside). At least one hollow portion may be formed in each terminal. The hollow portions function as a space to accommodate molten solder when the solid electrolytic capacitor is soldered to a substrate. The hollow portion functions to prevent solder from flowing out around the anode terminal and the cathode terminal, thereby improving the quality of board mounting by soldering. The distance between the outer edge of the hollow portion and the outer edge of the first portion may be 0.2 mm or more, except for the portion where the hollow portion straddles the outer edge of the first portion. With this configuration, when the solid electrolytic capacitor is soldered to a board, sufficient bonding strength can be ensured via a joint having a width of 0.2 mm or more.

[0016] The hollow portion may be a hollow hole. In other words, the hollow portion may have an outer periphery closed within the first portion. In this case, the hollow portion can be said to be open only toward the side opposite the exterior resin (i.e., the side toward the circuit board, etc.). With this configuration, soldering is performed along the entire periphery of the hollow portion (hollow hole), thereby increasing the bonding strength of the solid electrolytic capacitor to the substrate.

[0017] The hollow portion may penetrate the anode terminal and the cathode terminal in the thickness direction. In this case, the hollow portion has the same depth as the thickness of the anode terminal and the cathode terminal. This makes it easy to ensure a sufficient volume for the hollow portion, and therefore easy to ensure a sufficient space to accommodate molten solder.

[0018] The hollow portion does not have to penetrate the anode terminal and the cathode terminal in the thickness direction. In this case, the hollow portion is configured as a recess having a bottom. Therefore, when molding the capacitor element and each terminal with an exterior resin, there is no risk of molten resin flowing into the hollow portion from the exterior resin side, regardless of the type of solid electrolytic capacitor. The depth of the recess having a bottom (i.e., the distance between the surface of the terminal having the recess farthest from the exterior resin and the bottom) may be, for example, 30% or more, or 50% or more of the thickness of the terminal. The bottom can also be considered a ceiling when viewed from a circuit board, etc.

[0019] The exposed portion of the anode terminal may extend from the side surface of the exterior resin to the mounting surface without being bonded to the exterior resin. The exposed portion of the cathode terminal may extend from the side surface of the exterior resin to the mounting surface without being bonded to the exterior resin. In this case, the solid electrolytic capacitor is configured as a so-called gull-wing type solid electrolytic capacitor. For example, the exposed portions of the anode terminal and cathode terminal are bent toward the mounting surface at the boundary with the side surface of the exterior resin, and then further bent at the boundary between the side surface and the mounting surface to be aligned along the mounting surface. In this type of solid electrolytic capacitor, the first portion of each terminal does not come into contact with the exterior resin during the process of molding each component with the exterior resin. Therefore, regardless of the shape of the hollow portion, there is no risk of molten resin flowing into the hollow portion, making this type particularly suitable for application of the technology disclosed herein. However, the technology disclosed herein can also be applied to other types of solid electrolytic capacitors.

[0020] The ratio of the area of ​​the hollow portion to the area of ​​the portion (first portion) of the anode terminal and the cathode terminal exposed along the mounting surface may be 10% or more and 50% or less. For example, the ratio of the area of ​​the hollow portion formed in the anode terminal to the area of ​​the first portion of the anode terminal may be 10% or more and 50% or less. This configuration ensures both sufficient strength of the first portion of each terminal and sufficient space to accommodate molten solder. Note that when multiple hollow portions are formed in each terminal, the area of ​​the hollow portion refers to the total area of ​​the multiple hollow portions.

[0021] The anode section may include a porous anode body and an anode wire partially embedded in the anode body. The anode terminal may be connected to the anode wire. The cathode section may include a solid electrolyte layer disposed on the anode body with a dielectric layer interposed therebetween.

[0022] As described above, according to the present disclosure, when a solid electrolytic capacitor is mounted on a substrate by soldering, the mounting quality can be improved.

[0023] An example of a solid electrolytic capacitor according to the present disclosure will be specifically described below with reference to the drawings. The components described above can be applied to the components of the example solid electrolytic capacitor described below. The components of the example solid electrolytic capacitor described below can be modified based on the above description. Furthermore, the matters described below may be applied to the above-described embodiment. Of the components of the example solid electrolytic capacitor described below, components that are not essential for the solid electrolytic capacitor according to the present disclosure may be omitted. Note that the diagrams shown below are schematic and do not accurately reflect the shapes and numbers of actual components.

[0024] Embodiment 1 A first embodiment of the present disclosure will be described. As shown in Figures 1(a) and 1(b), a solid electrolytic capacitor 10 of this embodiment includes a capacitor element 11, an anode terminal 17, a cathode terminal 18, and an exterior resin 21. The solid electrolytic capacitor 10 has a substantially hexahedral outer shape.

[0025] Capacitor element 11 has an anode portion 12 and a cathode portion 13. Anode portion 12 has an anode body 12a, which is, for example, a hexahedral porous sintered body, and an anode wire 12b partially embedded in anode body 12a. Cathode portion 13 has a solid electrolyte layer 14 formed on a dielectric layer 16 formed on the surface of anode body 12a, and a cathode layer 15 covering part of the surface of solid electrolyte layer 14.

[0026] The anode body 12a is a porous sintered body obtained by sintering particles of a valve metal or the like (hereinafter simply referred to as metal particles). The metal particles are particles of a valve metal such as titanium, tantalum, or niobium. The anode body 12a uses 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 preferably contains a valve metal as the main component, with the valve metal accounting for 50 atomic % or more.

[0027] The anode wire 12b is, for example, a conductive wire. The material of the anode wire 12b is not particularly limited, and examples thereof include copper, aluminum, aluminum alloys, and the like, in addition to the valve metals described above. The materials constituting the anode body 12a and the anode wire 12b may be the same or different. The cross-sectional shape of the anode wire 12b is not particularly limited, and examples thereof include a circle, a squashed circle (a shape consisting of parallel straight lines and two curves connecting the ends of these lines; hereinafter referred to as a track shape), an ellipse, a rectangle, and a polygon. Among these, the track shape is preferred because it suppresses rolling during welding to the anode terminal 17 and facilitates positioning. The diameter of the anode wire 12b (the major axis in the case of a track shape or an ellipse) is also not particularly limited, and is, for example, 0.1 mm or more and 1.0 mm or less.

[0028] The anode body 12 is fabricated by, for example, embedding a portion of the anode wire 12b in metal particles, press-molding the embedded metal particles into a hexahedron (in this example, a rectangular parallelepiped), and sintering the hexahedron. As a result, the remaining portion of the anode wire 12b extends from the implantation surface (the left side surface in FIG. 1(a)) of the anode body 12a.

[0029] A dielectric layer 16 is formed on the surface of the anode body 12a. The dielectric layer 16 is made of, for example, a metal oxide. Examples of methods for forming a layer containing a metal oxide on the surface of the anode body 12a include a method of immersing the anode body 12a in a chemical conversion solution to anodize the surface of the anode body 12a, and a method of heating the anode body 12a in an atmosphere containing oxygen. The dielectric layer 16 is not limited to the above-mentioned layer containing a metal oxide, and may be any layer that is insulating.

[0030] The solid electrolyte layer 14 is formed so as to cover at least a portion of the dielectric layer 16, and covers at least a portion, preferably the entirety, of the implanted surface. This is expected to increase the capacitance of the solid electrolytic capacitor 10.

[0031] For example, a manganese compound or a conductive polymer is used for the solid electrolyte layer 14. Examples of conductive polymers include polypyrrole, polythiophene, polyfuran, polyaniline, polyacetylene, polyphenylene, polyparaphenylene vinylene, polyacene, polythiophene vinylene, polyfluorene, polyvinyl carbazole, polyvinyl phenol, polypyridine, and derivatives of these polymers. These may be used alone or in combination. The conductive polymer may also be a copolymer of two or more monomers. Among these, polythiophene, polyaniline, polypyrrole, and the like are preferred because of their excellent conductivity. Among these, polypyrrole is preferred because of its excellent water repellency.

[0032] The solid electrolyte layer 14 containing the conductive polymer is formed, for example, by polymerizing a raw material monomer on the dielectric layer 16 or by applying a liquid containing the conductive polymer to the dielectric layer 16. The solid electrolyte layer 14 is composed of one or more solid electrolyte layers. When the solid electrolyte layer 14 is composed of two or more solid electrolyte layers, the composition and formation method (polymerization method) of the conductive polymer used in each layer may be different.

[0033] 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).

[0034] 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 1,5-naphthalenedisulfonic acid, 1,6-naphthalenedisulfonic acid, 1-octane sulfonic acid, 1-naphthalenesulfonic acid, 2-naphthalenesulfonic acid, 2,6-naphthalenedisulfonic acid, 2,7-naphthalenedisulfonic acid, 2-methyl-5-isopropylbenzenesulfonic acid, 4-octylbenzenesulfonic acid, 4-nitrotoluene-2-sulfonic acid, m-nitrobenzenesulfonic acid, n-octyl sulfonic acid, n-butanesulfonic acid, n-hexanesulfonic acid, o-nitrobenzenesulfonic acid, p-ethylbenzenesulfonic acid, trifluoromethanesulfonic acid, hydroxybenzenesulfonic acid, butylnaphthalenesulfonic acid, benzenesulfonic acid, polystyrenesulfonic acid, polyvinylsulfonic acid, methanesulfonic acid, and derivatives thereof. Examples of the derivatives include metal salts such as lithium salts, potassium salts, and sodium salts; ammonium salts such as methylammonium salts, dimethylammonium salts, and trimethylammonium salts; piperidium salts, pyrrolidium salts, and pyrrolinium salts.

[0035] When the conductive polymer is dispersed in the dispersion medium in the form of particles, the average particle size D50 of the particles is preferably, 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 anode body 12 a.

[0036] The cathode layer 15 includes a carbon layer 15a and a metal (e.g., silver) paste layer 15b formed on the surface of the carbon layer 15a. The carbon layer 15a is formed so as to cover a portion of the solid electrolyte layer 14. The carbon layer 15a is made of a composition containing a conductive carbon material such as graphite. The metal paste layer 15b is made of a composition containing silver particles and a resin, for example. The configuration of the cathode layer 15 is not limited to this, and any configuration having a current collecting function may be used.

[0037] The anode terminal 17 is electrically connected to the anode portion 12. The anode terminal 17 is electrically connected to the anode body 12a via the portion of the anode wire 12b that protrudes from the anode body 12a. The material of the anode terminal 17 is not particularly limited as long as it is electrochemically and chemically stable and conductive, and may be metallic or non-metallic. The shape of the anode terminal 17 is also not particularly limited, and may be, for example, a long, flat plate having a first main surface and a second main surface. In this case, the thickness of the anode terminal 17 (the distance between the main surfaces of the anode terminal 17) is preferably 25 μm or more and 200 μm or less, more preferably 25 μm or more and 100 μm or less, from the viewpoint of reducing the height.

[0038] The anode terminal 17 may be joined to the anode wire 12b by a conductive adhesive or solder, or by resistance welding or laser welding. The conductive adhesive may be, for example, a mixture of a thermosetting resin and carbon particles or metal particles.

[0039] The cathode terminal 18 is electrically connected to the cathode portion 13. The cathode terminal 18 is electrically connected to the cathode layer 15. The material of the cathode terminal 18 is not particularly limited as long as it is electrochemically and chemically stable and conductive, and may be metallic or non-metallic. The shape of the cathode terminal 18 is also not particularly limited, and may be, for example, a long, flat plate having a first main surface and a second main surface. In this case, from the viewpoint of reducing the height, the thickness of the cathode terminal 18 is preferably 25 μm or more and 200 μm or less, and more preferably 25 μm or more and 100 μm or less. The cathode terminal 18 is bonded to the cathode layer 15 via, for example, a conductive adhesive 19.

[0040] The exterior resin 21 covers the capacitor element 11, the anode terminal 17, and the cathode terminal 18, leaving a portion of each of the anode terminal 17 and the cathode terminal 18 exposed. The exterior resin 21 has a mounting surface 21a (the lower surface in FIG. 1( a)) and four side surfaces that intersect with the mounting surface 21a. The exterior resin 21 is provided to electrically insulate the anode terminal 17 and the cathode terminal 18, and is made of an insulating material. The exterior resin 21 includes, for example, a cured thermosetting resin. Examples of thermosetting resins include epoxy resin, phenolic resin, silicone resin, melamine resin, urea resin, alkyd resin, polyurethane, polyimide, and unsaturated polyester.

[0041] The exterior resin 21 is formed, for example, by placing the thermosetting resin and the capacitor element 11, to which the anode terminal 17 and the cathode terminal 18 are connected, in a mold and then performing transfer molding, compression molding, or the like. At this time, the capacitor element 11 is covered with the exterior resin 21 so that at least a portion of the anode terminal 17 and the cathode terminal 18 are protruding from the exterior resin 21. The exterior resin 21 has an outer shape of, for example, a rectangular parallelepiped. The protruding portions of the anode terminal 17 and the cathode terminal 18 (hereinafter also referred to as exposed portions) are folded along the outer shape of the exterior resin 21 and positioned on the mounting surface 21a side of the exterior resin 21. The exposed portions of the anode terminal 17 and the cathode terminal 18 each extend from the side surface of the exterior resin 21 to the mounting surface 21a, and are not bonded to the exterior resin 21.

[0042] The portions (first portions 17a, 18a) of the anode terminal 17 and the cathode terminal 18 that are exposed along the mounting surface 21a of the exterior resin 21 have hollow portions 20 that open toward the side opposite the exterior resin 21 (downward in FIG. 1( a) ). As shown in FIG. 1( b) , the shape of the hollow portions 20 is square, but this is not limited thereto and they may have any other shape, such as a circle, a rectangle, or an oval. The shape and size of the hollow portions 20 of the anode terminal 17 and the cathode terminal 18 may be the same or different from each other.

[0043] The hollow portion 20 is a hollow hole that penetrates the anode terminal 17 and the cathode terminal 18 in the thickness direction. That is, in this embodiment, the depth of the hollow portion 20 is equal to the thickness of the anode terminal 17 and the cathode terminal 18. The area of ​​each first portion 17a, 18a used for soldering has an angular O-shape. The ratio of the area of ​​the hollow portion 20 to the area of ​​the first portion 17a, 18a of the anode terminal 17 and the cathode terminal 18 is preferably 10% or more and 50% or less, but is not limited to this range. The hollow portion 20 may be formed, for example, by punching the anode terminal 17 and the cathode terminal 18.

[0044] The distance between the outer edge of the hollow portion 20 and the outer edges of the first portions 17a, 18a is 0.2 mm or more. For example, in the example shown in FIG. 1( b), the distance between the right end of the first portion 17a of the anode terminal 17 and the right end of the hollow portion 20 of the anode terminal 17 may be 0.2 mm or more. Also, in the example shown in the same figure, the distance between the left end of the first portion 18a of the cathode terminal 18 and the left end of the hollow portion 20 of the cathode terminal 18 may be 0.2 mm or more. This is because, in the illustrated example, the distance between the outer edge of the hollow portion 20 and the outer edges of the first portions 17a, 18a is smallest at these locations.

[0045] The hollow portion 20 functions as a space for accommodating molten solder when the solid electrolytic capacitor 10 is soldered to a substrate (not shown). The function of the hollow portion 20 is to prevent the solder from flowing out around the anode terminal 17 and the cathode terminal 18, thereby improving the quality of the substrate mounting by soldering.

[0046] Second Embodiment A second embodiment of the present disclosure will be described. A solid electrolytic capacitor 10 of this embodiment differs from the first embodiment in the configuration of the hollow portion 20. The following mainly describes the differences from the first embodiment.

[0047] 2( a) and 2(b), hollow portion 20 in this embodiment is configured as a recess formed in first portions 17a, 18a of anode terminal 17 and cathode terminal 18. In other words, hollow portion 20 does not penetrate anode terminal 17 and cathode terminal 18 in the thickness direction. The depth of hollow portion 20 may be, for example, 20% or more and 80% or less of the thickness of anode terminal 17 and cathode terminal 18.

[0048] The hollow portion 20 straddles the outer edges of the first portions 17a, 18a. Specifically, in the example shown in Figure 2(b), the hollow portion 20 of the anode terminal 17 straddles the left edge of the first portion 17a of the anode terminal 17. In addition, in the example shown in the same figure, the hollow portion 20 of the cathode terminal 18 straddles the right edge of the first portion 18a of the cathode terminal 18. The area used for soldering in each of the first portions 17a, 18a has an angular U-shape.

[0049] The present disclosure can be used for solid electrolytic capacitors.

[0050] 10: Solid electrolytic capacitor 11: Capacitor element 12: Anode portion 12a: Anode body 12b: Anode wire 13: Cathode portion 14: Solid electrolyte layer 15: Cathode layer 15a: Carbon layer 15b: Metal paste layer 16: Dielectric layer 17: Anode terminal 17a: First portion 18: Cathode terminal 18a: First portion 19: Conductive adhesive 20: Hollow portion 21: Exterior resin 21a: Mounting surface

Claims

1. At least one capacitor element having an anode portion and a cathode portion, An anode terminal electrically connected to the anode portion, A cathode terminal electrically connected to the cathode portion, An exterior resin that covers the capacitor element, the anode terminal, and the cathode terminal in a state where a part of each of the anode terminal and the cathode terminal is exposed, Comprising, The exterior resin has a mounting surface and four side surfaces intersecting the mounting surface, A solid electrolytic capacitor in which a hollow portion that opens toward the side opposite to the exterior resin is formed in a portion of the anode terminal and the cathode terminal that is exposed along the mounting surface.

2. The solid electrolytic capacitor according to claim 1, wherein the hollow portion is constituted by a hollow hole.

3. The solid electrolytic capacitor according to claim 1 or 2, wherein the hollow portion penetrates the anode terminal and the cathode terminal in the thickness direction.

4. The solid electrolytic capacitor according to claim 1 or 2, wherein the hollow portion does not penetrate the anode terminal and the cathode terminal in the thickness direction.

5. The exposed portion of the anode terminal extends from the side surface of the exterior resin to the mounting surface and is not adhered to the exterior resin, The exposed portion of the cathode terminal extends from the side surface of the exterior resin to the mounting surface and is not adhered to the exterior resin. The solid electrolytic capacitor according to claim 1 or 2.

6. The solid electrolytic capacitor according to claim 1 or 2, wherein the ratio of the area of the hollow portion to the area of the portion of the anode terminal and the cathode terminal that is exposed along the mounting surface is 10% or more and 50% or less.

7. The anode portion has a porous anode body and an anode wire partially embedded in the anode body, The anode terminal is connected to the anode wire, The solid electrolytic capacitor according to claim 1 or 2, wherein the cathode portion has a solid electrolyte layer disposed on the anode body via a dielectric layer.