Stacked capacitors
By designing a structure in which the anode protrudes in different directions in the multilayer capacitor and connecting it with multiple terminals to form an extended transmission line, the problem of insufficient noise filtering performance of existing multilayer capacitors in high-frequency equipment is solved, and a higher noise reduction effect is achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
- Filing Date
- 2025-01-15
- Publication Date
- 2026-07-31
AI Technical Summary
Existing multilayer capacitors have insufficient noise filtering performance in high-frequency electronic equipment, making it difficult to meet the requirements for improvement.
Design a stacked capacitor structure in which the anode of the capacitor element protrudes in different directions and is connected by multiple anode and cathode terminals to form an extended transmission line to enhance noise filtering function.
By extending the transmission line, the noise reduction capability of the stacked capacitors is significantly improved, especially the noise suppression effect under high-frequency signals.
Smart Images
Figure CN122498014A_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to stacked capacitors. Background Technology
[0002] Previously, surface-mount type stacked capacitors known as transmission line noise filters were known (e.g., Patent Document 1). The stacked capacitor in Patent Document 1 includes: a box-shaped resin molded housing base, a plurality of capacitor elements stacked with anodes at both ends and a cathode in the center, and a box-shaped housing cover.
[0003] Existing technical documents
[0004] Patent documents
[0005] Patent Document 1: Japanese Patent Application Publication No. 2009-076651 Summary of the Invention
[0006] The problem the invention aims to solve
[0007] In recent years, due to the increasingly higher operating frequencies of electronic devices, there is a growing expectation for further improvements in the performance of multilayer capacitors.
[0008] Solution for solving the problem
[0009] One aspect of this disclosure relates to a stacked capacitor. The stacked capacitor comprises: a first capacitor element and a second capacitor element, each having an anode body, a cathode portion, and a dielectric layer between the anode body and the cathode portion, and stacked on top of each other. The anode body of the first capacitor element has: a first portion protruding from the cathode portion in a region on one side of a first direction; and a second portion protruding from the cathode portion in a region on the other side of the first direction. The anode body of the second capacitor element has: a third portion protruding from the cathode portion in a region on one side of the first direction; and a fourth portion protruding from the cathode portion in a region on the other side of the first direction.
[0010] The stacked capacitor includes: a first anode terminal electrically connected to a first portion of the first capacitor element; a second anode terminal electrically connected to a third portion of the second capacitor element; and a cathode terminal electrically connected to the cathode portions of the first capacitor element and the second capacitor element, wherein the second portion and the fourth portion are electrically connected to each other.
[0011] The effects of the invention
[0012] According to this disclosure, it is possible to provide stacked capacitors that reduce noise. Attached Figure Description
[0013] Figure 1This is a schematic cross-sectional view of the stacked capacitor of Embodiment 1, (a) showing the cross-section along... Figure 2 (a) shows the cross section of line IA-IA, and (b) shows the section along line IA-IA. Figure 2 The cross section of the IB-IB line in (a).
[0014] Figure 2 This is a schematic cross-sectional view of the stacked capacitor of Embodiment 1, (a) showing the cross-section along... Figure 1 (a) shows the cross section of line IIA-IIA, and (b) shows the section along line IIA-IIA. Figure 1 (a) Cross section of line IIB-IIB.
[0015] Figure 3 These are schematic side cross-sectional views of capacitor elements. (a) shows a capacitor element when the stacked capacitor is a solid electrolytic capacitor, and (b) shows a capacitor element when the stacked capacitor is a ceramic capacitor.
[0016] Figure 4 This is a perspective view schematically showing the first and second capacitor elements and the cathode terminal of Embodiment 1.
[0017] Figure 5 This is a perspective view schematically showing the first and second capacitor elements and the cathode terminal of Embodiment 2.
[0018] Figure 6 This is a perspective view schematically representing the stacked capacitor of Embodiment 3, (a) showing the first and second capacitor elements, and (b) showing them covered by the outer casing. Detailed Implementation
[0019] The following examples illustrate embodiments of the multilayer capacitors disclosed herein. However, this disclosure is not limited to the examples described below. Specific values and materials are sometimes illustrated in the following description, but other values and materials can be applied as long as the effects of this disclosure are achieved.
[0020] The stacked capacitor of the present invention can be used as a transmission line component with noise filtering function. The stacked capacitor disclosed herein includes: a first capacitor element, a second capacitor element, a first anode terminal, a second anode terminal, and a cathode terminal. It should be noted that there can be two or more anode terminals and one or more cathode terminals.
[0021] The first capacitor element has an anode body, a cathode portion, and a dielectric layer. The anode body, for example, is sheet-like and may have a shape comprising two opposite sides in a first direction and two opposite sides in a second direction intersecting the first direction (typically a quadrilateral). The quadrilateral is preferably a rectangle with a short side and a long side. The anode body of the first capacitor element has a first portion protruding from the cathode portion in a region on one side of the first direction and a second portion protruding from the cathode portion in a region on the other side of the first direction. The first direction is preferably the length direction of the anode body. The first direction may be perpendicular to the stacking direction, and the second direction may be perpendicular to both the first and stacking directions. The region on one side of the first direction and the region on the other side of the first direction refer to the region on one side and the region on the other side when the anode body is equally divided into two regions in the first direction (preferably its length direction) (the same applies to the anode body of the second capacitor element). When multiple first capacitor elements are present, adjacent first portions in the stacking direction and adjacent second portions in the stacking direction may also be electrically connected to each other.
[0022] The second capacitor element has an anode body, a cathode portion, and a dielectric layer. The anode body of the second capacitor element has a third portion protruding from the cathode portion in a region on one side of a first direction, and a fourth portion protruding from the cathode portion in a region on the other side of the first direction. When multiple second capacitor elements are present, adjacent third portions in the stacking direction and adjacent fourth portions in the stacking direction can also be electrically connected to each other.
[0023] The first capacitor element and the second capacitor element are stacked on top of each other. The number of first capacitor elements and the number of second capacitor elements are not particularly limited. The stacking order of the first capacitor elements and the second capacitor elements is independent of the number of capacitor elements and is not particularly limited. When there are multiple first capacitor elements, the first portions are electrically connected to each other, and the second portions are electrically connected to each other. When there are multiple second capacitor elements, the third portions are electrically connected to each other, and the fourth portions are electrically connected to each other.
[0024] The anodes of the first and second capacitor elements can also be made of a valve-acting metal. Examples of valve-acting metals constituting the anodes include aluminum, tantalum, niobium, and titanium. The anode can be a foil of the valve-acting metal or a sintered body of valve-acting metal particles. Alternatively, the anodes of the first and second capacitor elements can also be made of metals other than the valve-acting metal, or they can be vapor-deposited metals. Examples of such metals include silver, nickel, and palladium.
[0025] The dielectric layer of the first and second capacitor elements may also cover at least a portion of the surface of the anode body. The dielectric layer may also be composed of an oxide (e.g., alumina) formed on the surface of the anode body by liquid-phase methods such as anodic oxidation, vapor deposition, or atomic layer deposition. Alternatively, the dielectric layer may be composed of sintered particles of a dielectric magnetic composition. The dielectric magnetic composition may, for example, be primarily composed of barium titanate. The dielectric layer is formed at least between the anode body and the cathode portion.
[0026] The cathode portions of the first and second capacitor elements may also have a solid electrolyte layer covering at least a portion of the surface of the dielectric layer, and a cathode layer covering at least a portion of the surface of the solid electrolyte layer. Adjacent cathode portions in the stacking direction may also be electrically connected to each other. The solid electrolyte layer may also contain a conductive polymer. The solid electrolyte layer may also further contain a dopant if necessary. Alternatively, the cathode portion may be a metal layer composed of silver, nickel, palladium, etc., or it may be a vapor-deposited metal.
[0027] As conductive polymers, known materials used in solid electrolytic capacitors, such as π-conjugated conductive polymers, can be used. Examples of conductive polymers include those with a basic backbone of polypyrrole, polythiophene, polyaniline, polyfuran, polyacetylene, polyphenylene, polyphenylenevinylene, polyphenylene oxide, and polythiophene vinylene. Among these, polymers with a basic backbone of polypyrrole, polythiophene, or polyaniline are preferred. These polymers also include homopolymers, copolymers of two or more monomers, and their derivatives (substitutes with substituents, etc.). For example, polythiophene includes poly(3,4-ethylenedioxythiophene). A single conductive polymer can be used, or two or more can be used in combination.
[0028] As a dopant, at least one selected from the group consisting of low-molecular-weight anions and polyanions is used. Examples of low-molecular-weight anions include sulfate ions, nitrate ions, phosphate ions, borate ions, organic sulfonate ions, and carboxylate ions, without particular limitation. Examples of dopants that generate organic sulfonate ions include benzenesulfonic acid, p-toluenesulfonic acid, and naphthalenesulfonic acid. Examples of polyanions include high-molecular-weight polysulfonic acids and high-molecular-weight polycarboxylic acids. Examples of high-molecular-weight polysulfonic acids include polyvinylsulfonic acid, polystyrene sulfonic acid, polyallyl sulfonic acid, polyacrylic acid sulfonic acid, and polymethacrylic acid sulfonic acid. Examples of high-molecular-weight polycarboxylic acids include polyacrylic acid and polymethacrylic acid. Polyanions also include polyester sulfonic acid and phenol sulfonic acid phenolic resins. However, polyanions are not limited to these.
[0029] The solid electrolyte layer may further include, as needed, known additives and known conductive materials other than conductive polymers. Examples of such conductive materials include at least one selected from the group consisting of conductive inorganic materials such as manganese dioxide and TCNQ (7,7,8,8-tetracyano-p-benzoquinone dimethane) complex salts.
[0030] The cathode layer may also consist of a carbon layer formed on the surface of the solid electrolyte layer and a conductive layer formed on the surface of the carbon layer. The conductive layer may also be composed of a silver paste. As the silver paste, a composition containing, for example, silver particles and a resin component (binder resin) can be used. As the resin component, thermoplastic resins can also be used, but thermosetting resins such as imide resins and epoxy resins are preferred. Alternatively, the conductive layer may also use a metal foil with an aluminum or copper substrate.
[0031] The first anode terminal is electrically connected to a first portion of the first capacitor element. In the case of multiple first capacitor elements, the first anode terminal may also be electrically connected to the first portions of all the first capacitor elements. The first anode terminal may also be divided into two or more parts. The first anode terminal may be made of copper, a copper alloy, aluminum, or an aluminum alloy, and may be plated. Alternatively, the first anode terminal may have: a conductive body layer comprising conductive particles and resin material (e.g., a silver paste layer), and at least one plating layer (e.g., a Ni / Sn plating layer). The first anode terminal may be electrically connected to the first portion by riveting or by welding (e.g., laser welding or resistance welding). Additionally, the first anode terminal may also be a current collector exposed from the end face of the outer casing.
[0032] The second anode terminal is electrically connected to the third portion of the second capacitor element. When multiple second capacitor elements exist, the second anode terminal may also be electrically connected to the third portion of all of the second capacitor elements. The second anode terminal may also be divided into two or more parts. The material of the second anode terminal may be the same as or different from that of the first anode terminal. The second anode terminal can be electrically connected to the third portion by riveting or by welding (e.g., laser welding or resistance welding). Alternatively, the second anode terminal may also collect electricity from the exposed end face of the outer casing.
[0033] One of the first anode terminal and the second anode terminal may be disposed on one side of the second direction, and the other of the first anode terminal and the second anode terminal may be disposed on the other side of the second direction. The first anode terminal and the third anode terminal may also be separate from each other in the second direction. In the second direction, the length of the first anode terminal may be 50% or less, or 45% or less, of the length of the first capacitor element. In the second direction, the length of the second anode terminal may also be 50% or less, or 45% or less, of the length of the second capacitor element.
[0034] The cathode terminal is electrically connected to the cathode portion of both the first and second capacitor elements. That is, the cathode terminal is electrically connected to all cathode portions. The cathode terminal can also be electrically connected to the cathode portion via a conductive adhesive. The cathode terminal can be made of copper, copper alloy, aluminum, or aluminum alloy, and can be plated or vapor-deposited. The constituent material of the cathode terminal can be the same as or different from that of the first anode terminal. The cathode terminal can also be divided into two or more parts. Furthermore, the cathode terminal can also collect current from its exposed end face within the outer casing.
[0035] The second part of the first capacitor element and the fourth part of the second capacitor element are electrically connected to each other. This electrical connection can also be achieved by any method. For example, the second part and the fourth part can be electrically connected via metal terminals, or they can be electrically connected by cold pressing, laser welding, etc.
[0036] The multilayer capacitor having the above configuration has a transmission line (or current path) in the following order (or reverse order): a first anode terminal, a first portion, a main body portion of a first capacitor element (i.e., the portion of the first capacitor element excluding the first and second portions), a second portion, a fourth portion, a main body portion of a second capacitor element (i.e., the portion of the second capacitor element excluding the third and fourth portions), a third portion, and a second anode terminal. When a current containing noise components flows through these transmission lines, the noise components can be reduced by flowing into the cathode portions and cathode terminals of each capacitor element. The longer the transmission line, the higher this noise reduction function becomes. Furthermore, the transmission line of the multilayer capacitor according to this disclosure includes the main bodies of the first capacitor element and the main bodies of the second capacitor element in series, and is therefore longer than the transmission line of a conventional multilayer capacitor (i.e., a transmission line containing only the main body portion of one capacitor element). Therefore, the multilayer capacitor according to this disclosure can have a high noise reduction function relative to its size.
[0037] The multilayer capacitor disclosed herein may also have a third anode terminal electrically connected to the second portion of the first capacitor element and the fourth portion of the second capacitor element. In this case, the multilayer capacitor is a 4-terminal type multilayer capacitor. Such a 4-terminal type multilayer capacitor, in addition to its use as a multilayer capacitor with a long transmission line as described above, can also be used, for example, in a configuration where the third anode terminal is used as an input terminal and the first and second anode terminals are used as output terminals respectively. The third anode terminal may also be divided into two or more parts. The third anode terminal may be made of copper, copper alloy, aluminum, or aluminum alloy, and may also be plated. The third anode terminal can be electrically connected to the second and fourth portions either by riveting or by welding (e.g., laser welding or resistance welding). Furthermore, the third anode terminal may also be a collector surface exposed from the outer casing.
[0038] The first part may also protrude from the cathode portion of the first capacitor element toward one side in the first direction. The second part may also protrude from the cathode portion of the first capacitor element toward the other side in the first direction. The third part may also protrude from the cathode portion of the second capacitor element toward one side in the first direction. The fourth part may also protrude from the cathode portion of the second capacitor element toward the other side in the first direction. In this case, the transmission line between the first and second parts and the transmission line between the fourth and third parts become longer. Therefore, by further extending the transmission line from the first part to the third part, the noise reduction performance of the multilayer capacitor can be further improved. It should be noted that at least one of the first and second parts may also protrude from the cathode portion of the first capacitor element toward the second direction (i.e., Figure 1 The third and fourth portions protrude from the cathode portion of the second capacitor element in the second direction (vertical direction of the paper).
[0039] At least one of the first and second portions may also protrude from the cathode portion of the first capacitor element in a second direction. In this case, it is easy to ensure a larger distance between the first and second portions, which increases the flexibility in the configuration of the first and second anode terminals electrically connected to them. The second direction may also intersect (preferably perpendicular to) the stacking direction and the first direction.
[0040] The cathode terminal may also have: a mounting face disposed at one end in the stacking direction of the first capacitor element and the second capacitor element; and a sidewall portion continuously raised from the mounting face and electrically connected to the side of each cathode portion of the first and second capacitor elements. The mounting face and the sidewall portion are integrally formed with each other. The mounting face may also be electrically connected to the cathode portion of the nearest first or second capacitor element. The sidewall portion may also be electrically connected to the side of each cathode portion via a conductive adhesive. By having such a sidewall portion, the impedance of the resistive and inductive components originating from the cathode terminal can be reduced, improving the noise reduction function of the stacked capacitor. In addition, since the sidewall portion is integrally formed with the mounting face, the cathode terminal having the mounting face and the sidewall portion can be easily manufactured, for example, by bending a specified frame material.
[0041] The first capacitor element and the second capacitor element may also have a conductive polymer layer covering at least a portion of the dielectric layer, or a ceramic layer constituting the dielectric layer. The conductive polymer layer may contain conductive polymers of the types described above. The ceramic layer may contain, for example, barium titanate and secondary components. As secondary components, they may include: at least one of the rare earth elements selected from dysprosium, holmium, erbium, and yttrium; at least one of manganese and vanadium; at least one of silicon and aluminum; barium; and magnesium.
[0042] At least multiple second capacitor elements can be provided. In this case, the capacitance of the stacked capacitor can be increased, and the equivalent series resistance and impedance of the stacked capacitor can be reduced. It should be noted that multiple first capacitor elements and multiple second capacitor elements can also be provided. The number of first capacitor elements and the number of second capacitor elements can be the same or different.
[0043] The first capacitor element and multiple second capacitor elements can also be stacked alternately. In this case, the direction of the current flowing through the first capacitor element is opposite to the direction of the current flowing through the second capacitor element. Therefore, by alternately stacking the two capacitor elements, the equivalent series inductance of the stacked capacitors can be reduced.
[0044] The cathode terminal may also have a mounting surface disposed at one end of the stacking direction of the first and second capacitor elements. Multiple second capacitor elements may also be stacked together on one side of the mounting surface. The first capacitor elements may also be stacked on the opposite side of the mounting surface. The mounting surface may also be electrically connected to the cathode portion of the nearest second capacitor element. Here, the closer to the mounting surface, the higher the noise reduction function of the current flowing through the capacitor element. Therefore, when using a stacked capacitor with this configuration as output terminals, with the first and second anode terminals respectively, it is advisable to connect the output terminal corresponding to the second capacitor element stacked together on the mounting surface side to a circuit with relatively strict noise requirements. The cathode terminal may also further have a sidewall portion that continuously rises from the mounting surface and is electrically connected to the side of each cathode portion of the first and second capacitor elements.
[0045] As described above, according to this disclosure, it is possible to provide a stacked capacitor that has a high noise reduction function by extending the transmission line.
[0046] Hereinafter, an example of a multilayer capacitor according to the present disclosure will be specifically described with reference to the accompanying drawings. The constituent elements of the multilayer capacitor in the example described below can be applied using the constituent elements described above. The constituent elements of the multilayer capacitor in the example described below can be modified based on the above description. Furthermore, the matters to be explained below can also be applied to the above-described embodiments. In the constituent elements of the multilayer capacitor in the example described below, constituent elements not essential to the multilayer capacitor according to the present disclosure may be omitted. It should be noted that the figures shown below are schematic diagrams and do not accurately reflect the shape and number of actual components.
[0047] Implementation Method 1
[0048] Embodiment 1 of this disclosure will be described. For example... Figures 1-4 As shown, the stacked capacitor 10 of this embodiment includes at least one (two in this example) first capacitor element 20, at least one (two in this example) second capacitor element 30, a first anode terminal 51, a second anode terminal 52, a third anode terminal 53, a cathode terminal 60, and an outer casing 70. It should be noted that... Figure 1 In the middle, the side wall portion 60b, which will be described later, is indicated by a double-dotted line.
[0049] The first capacitor element 20 has a first anode body 21, a first cathode portion 22, and a first dielectric layer 23. The first anode body 21 has a portion on one side along its length ( Figure 1 The first portion 21a protruding from the first cathode portion 22 in the region on the left side of the first cathode portion 22, and on the other side in the length direction ( Figure 1The second portion 21b protrudes from the first cathode portion 22 in the area to the right of the first anode body 21. The first capacitor element 20 also has a first insulating portion 24 disposed between the first anode body 21 and the first cathode portion 22 and electrically insulating the two. The first anode body 21 is an example of an anode body. The first cathode portion 22 is an example of a cathode portion. The first dielectric layer 23 is an example of a dielectric layer. Figure 1 The length direction in the middle is an example of the first direction.
[0050] The second capacitor element 30 has a second anode body 31, a second cathode portion 32, and a second dielectric layer 33. The second anode body 31 has a portion on one side along its length ( Figure 1 The third portion 31a protruding from the second cathode portion 32 in the region on the left side, and on the other side in the length direction ( Figure 1 The fourth portion 31b protrudes from the second cathode portion 32 in the region on the right side of the image. The second capacitor element 30 also has a second insulating portion 34 disposed between the second anode body 31 and the second cathode portion 32, and electrically insulating the two. The second anode body 31 is an example of an anode body. The second cathode portion 32 is an example of a cathode portion. The second dielectric layer 33 is an example of a dielectric layer.
[0051] The first part 21a extends from the first cathode portion 22 along the length direction to one side ( Figure 1 The second part 21b protrudes from the left side of the first cathode portion 22 along the length direction. Figure 1 The third part 31a protrudes from the second cathode part 32 along the length direction (to the right). Figure 1 The fourth part 31b protrudes from the second cathode part 32 to the other side in the length direction. Figure 1 (Protruding to the right of the middle). It should be noted that the first to fourth parts 21a, 21b, 31a, 31b can also extend from the first or second cathode part 22, 32 in the width direction ( Figure 1 The vertical direction of the paper is highlighted. The width direction is an example of the second direction.
[0052] Two first capacitor elements 20 and two second capacitor elements 30 are stacked on top of each other. In this embodiment, the two first capacitor elements 20 and the two second capacitor elements 30 are stacked alternately.
[0053] The first anode 21 and the second anode 31 are each made of foil of a valve-acting metal (aluminum in this example), but are not limited thereto. The first portions 21a of the two first anodes 21 are electrically connected to each other. The third portions 31a of the two second anodes 31 are electrically connected to each other. The first portions 21a and the third portions 31a are on one side of the length direction of the stacked capacitor 10 (…). Figure 1The left side of the stacked capacitor 10 is not directly connected. In other words, the first part 21a and the third part 31a are in the width direction of the stacked capacitor 10. Figure 1 They are separated from each other in the vertical direction of the paper.
[0054] like Figure 3 As shown in (a), a first dielectric layer 23 covers at least a portion of the surface of the first anode body 21. The first dielectric layer 23 is composed of an oxide (in this example, aluminum oxide) formed on the roughened surface of the first anode body 21, but is not limited thereto. A second dielectric layer 33 covers at least a portion of the surface of the second anode body 31. The second dielectric layer 33 is composed of an oxide (in this example, aluminum oxide) formed on the roughened surface of the second anode body 31, but is not limited thereto.
[0055] The first cathode portion 22 has a solid electrolyte layer (conductive polymer layer) covering at least a portion of the first dielectric layer 23 and a cathode layer covering at least a portion of the surface of the solid electrolyte layer. The second cathode portion 32 has a solid electrolyte layer (conductive polymer layer) covering at least a portion of the second dielectric layer 33 and a cathode layer covering at least a portion of the surface of the solid electrolyte layer. In the stacking direction ( Figure 1 The first cathode portion 22 and the second cathode portion 32, which are adjacent in the vertical direction, are electrically connected to each other via a conductive paste 40. Therefore, all the first cathode portions 22 and the second cathode portions 32 are electrically connected to each other. The solid electrolyte layer includes a conductive polymer and a dopant. The cathode layer consists of a carbon layer formed on the surface of the solid electrolyte layer and a conductive layer formed on the surface of the carbon layer. The conductive layer may also be composed of a silver paste. Alternatively, the conductive layer may use a metal foil with aluminum or copper as the substrate.
[0056] It should be noted that the stacked capacitor 10 in this embodiment is equipped with Figure 3 Solid electrolytic capacitors of the type of first and second capacitor elements 20, 30 shown in (a), but not limited thereto, possessing Figure 3 The multilayer ceramic capacitors of the type shown in (b) for the first and second capacitor elements 20, 30 are also applicable to the technical concept of this disclosure. Figure 3 (b) The first and second capacitor elements 20 and 30 are briefly described, wherein the first and second anode bodies 21 and 31 are composed of metal layers formed inside the first and second dielectric layers 23 and 33 (ceramic layers) containing barium titanate as the main component, and the first and second cathode portions 22 and 32 are composed of metal layers formed on the surfaces of the first and second dielectric layers 23 and 33. The first and second cathode portions 22 and 32 are in Figure 3 (b) The front and inner sides of the paper protrude from the first and second anode bodies 21, 31 in the vertical direction.
[0057] The first anode terminal 51 is electrically connected to the first portion 21a of the first capacitor element 20. The first anode terminal 51 is made of copper alloy, but is not limited to this. The first anode terminal 51 is electrically connected to the first portion 21a by riveting. It should be noted that, instead of riveting, or based on riveting, the first anode terminal 51 can be soldered to the first portion 21a.
[0058] The second anode terminal 52 is electrically connected to the third part 31a of the second capacitor element 30. The second anode terminal 52 is made of a copper alloy, but is not limited to this. The second anode terminal 52 is electrically connected to the third part 31a by riveting. It should be noted that, alternatively, or in addition to riveting, the second anode terminal 52 can be soldered to the third part 31a.
[0059] The third anode terminal 53 is electrically connected to the second portion 21b of the first capacitor element 20 and the fourth portion 31b of the second capacitor element 30. Thus, the second portion 21b and the fourth portion 31b are electrically connected to each other. The third anode terminal 53 is made of a copper alloy, but is not limited to this. The third anode terminal 53 is electrically connected to the second portion 21b and the fourth portion 31b by riveting. It should be noted that, instead of riveting, or based on riveting, the third anode terminal 53 can also be welded to the second portion 21b and the fourth portion 31b. It should be noted that this electrical connection can also be achieved inside the stacked capacitor 10 (or inside the outer casing 70) without via the third anode terminal 53. Examples of this method include cold pressing or laser welding.
[0060] The cathode terminal 60 is electrically connected to the first cathode portion 22 and the second cathode portion 32, for example, via a conductive adhesive (not shown). The cathode terminal 60 is made of a copper alloy, but is not limited thereto.
[0061] The cathode terminal 60 has one end disposed in the stacking direction of the first and second capacitor elements 20, 30. Figure 1 The mounting surface 60a (at the lower end of the middle) and the sidewall portion 60b, which is continuously erected from the mounting surface 60a and electrically connected to the sides of the first cathode portion 22 and the second cathode portion 32. The mounting surface 60a and the nearest ( Figure 1 The second cathode portion 32 of the second capacitor element 30 (at the lowest side) is electrically connected. The sidewall portion 60b is electrically connected to the sides of each first cathode portion 22 and each second cathode portion 32 via a conductive adhesive (not shown). The cathode terminal 60 preferably has a connection to both the sides of each first cathode portion 22 and each second cathode portion 32. Figure 1 The two or more sidewall portions 60b of the paper surface near the front and inner sides are electrically connected.
[0062] The outer casing 70 covers the first and second capacitor elements 20, 30, the first and third anode terminals 51-53, and the cathode terminal 60, with portions of each of the first to third anode terminals 51-53 and the cathode terminal 60 exposed. The outer casing 70 can be made of any insulating material, such as resin or ceramic, and is not limited thereto. The exposed portions of the first to third anode terminals 51-53 function as external terminals of the stacked capacitor 10.
[0063] Implementation Method 2
[0064] Embodiment 2 of this disclosure will be described. The stacking order of the first and second capacitor elements 20, 30 of the stacked capacitor 10 in this embodiment is different from that in Embodiment 1 described above. Hereinafter, the differences from Embodiment 1 will be mainly described.
[0065] like Figure 5 As shown, in this embodiment, a plurality of (two in this example) second capacitor elements 30 are stacked together on the mounting surface 60a side of the cathode terminal 60. Figure 5 (on the lower side), and multiple (two in this example) first capacitor elements 20 are stacked together on the opposite side of the mounting surface 60a. Figure 5 (The upper side of the middle).
[0066] Implementation Method 3
[0067] Embodiment 3 of this disclosure will be described. The multilayer capacitor 10 of this embodiment differs from that of Embodiment 1 described above in that it is a so-called end-face collector type multilayer capacitor. Hereinafter, the differences from Embodiment 1 will be mainly described.
[0068] like Figure 6 As shown, the stacked capacitor 10 of this embodiment includes a plurality of cathode bodies C that are electrically connected to the cathode portions 22, 32 of each capacitor element 20, 30 and protrude to both sides in a second direction between the cathode portions 22, 32. In each cathode body C, the portion protruding to one side in the second direction is electrically connected to the portion protruding to the other side. Each cathode body C may be made of metal foil or vapor-deposited metal. Figure 6 The state shown in (a) is achieved by covering each constituent element with the outer casing 70, thus becoming Figure 6 The state shown in (b). Then, from Figure 6 In the state shown in (b), the portions of the first to fourth parts 21a, 21b, 31a, 31b and the portions of each cathode body C exposed from the outer casing 70 are respectively formed, for example, by plating, into the first to third anode terminals and cathode terminals (not shown), thereby obtaining a face-collector type multilayer capacitor 10. It should be noted that in Figure 6In the figure, the two protruding parts of each cathode body C are marked with the reference numeral "C" for ease of understanding. Each cathode body C is an element extending along the second direction.
[0069] Postscript
[0070] Based on the description of the above embodiments, the following technology is disclosed.
[0071] (Technology 1)
[0072] A multilayer capacitor comprises: a first capacitor element and a second capacitor element, each having an anode body, a cathode portion, and a dielectric layer disposed between the anode body and the cathode portion and stacked on top of each other.
[0073] The anode body of the first capacitor element has:
[0074] The first part, in a region on one side in a first direction, protrudes from the cathode portion; and
[0075] The second part protrudes from the cathode portion in the region on the other side of the first direction.
[0076] The anode body of the second capacitor element has:
[0077] The third part, in the region on one side of the first direction, protrudes from the cathode portion; and
[0078] The fourth part, in the region on the other side of the first direction, protrudes from the cathode portion.
[0079] The stacked capacitor comprises:
[0080] The first anode terminal is electrically connected to the first portion of the first capacitor element;
[0081] The second anode terminal is electrically connected to the third portion of the second capacitor element; and
[0082] The cathode terminal is electrically connected to the cathode portion of the first capacitor element and the second capacitor element.
[0083] The second part is electrically connected to the fourth part.
[0084] (Technology 2)
[0085] According to the stacked capacitor of technology 1, it includes a third anode terminal electrically connected to the second portion of the first capacitor element and the fourth portion of the second capacitor element.
[0086] (Technology 3)
[0087] According to the stacked capacitor of technique 1 or 2, the first portion protrudes from the cathode portion of the first capacitor element toward one side in the first direction.
[0088] The second portion protrudes from the cathode portion of the first capacitor element to the other side in the first direction.
[0089] The third portion protrudes from the cathode portion of the second capacitor element toward one side in the first direction.
[0090] The fourth portion protrudes from the cathode portion of the second capacitor element to the other side in the first direction.
[0091] (Technology 4)
[0092] According to the stacked capacitor of technique 1 or 2, at least one of the first portion and the second portion protrudes from the cathode portion of the first capacitor element in a second direction.
[0093] (Technology 5)
[0094] The multilayer capacitor according to any one of techniques 1 to 4, wherein the cathode terminal has:
[0095] The mounting face is disposed at one end of the stacking direction of the first capacitor element and the second capacitor element; and
[0096] The sidewall portion rises continuously from the mounting surface and is electrically connected to the side of the cathode portion of each of the first capacitor element and the second capacitor element.
[0097] (Technology 6)
[0098] The multilayer capacitor according to any one of techniques 1 to 5, wherein the first capacitor element and the second capacitor element have a conductive polymer layer covering at least a portion of the dielectric layer, or have a ceramic layer constituting the dielectric layer.
[0099] (Technology 7)
[0100] The stacked capacitor according to any one of techniques 1 to 6, wherein at least a plurality of the second capacitor elements are provided.
[0101] (Technology 8)
[0102] According to the stacked capacitor of technology 7, the first capacitor element is alternately stacked with the plurality of second capacitor elements.
[0103] (Technology 9)
[0104] According to the stacked capacitor of technology 7, the cathode terminal has a mounting surface disposed at one end in the stacking direction of the first capacitor element and the second capacitor element.
[0105] The plurality of second capacitor elements are stacked together on the mounting surface side.
[0106] The first capacitor element is stacked on the opposite side of the mounting surface.
[0107] Example
[0108] The characteristics of the multilayer capacitors of the embodiments and comparative examples shown below were evaluated. Specifically, for the multilayer capacitors of the embodiments, the noise suppression amount to the second anode terminal when a noise signal of 1MHz or 100MHz was input from the first anode terminal was evaluated; for the multilayer capacitors of the comparative examples, the noise suppression amount to the other anode terminal when a noise signal of 1MHz or 100MHz was input from one anode terminal was evaluated.
[0109] Example
[0110] The type of stacked capacitor shown in Embodiment 1 above was evaluated. It should be noted that the first capacitor element and the second capacitor element are stacked alternately in groups of three (a total of six). The noise suppression is -108 dB for a 1 MHz noise signal and -136 dB for a 100 MHz noise signal.
[0111] Comparative Examples
[0112] A stacked capacitor comprising six capacitor elements of a different type than those in the embodiment was evaluated. This capacitor element has an anode body, a cathode portion, and a dielectric material between them. The anode body has two protrusions extending longitudinally from the cathode portion to both sides. The stacked capacitor of the comparative example has an anode terminal electrically connected to one protrusion and an anode terminal electrically connected to the other protrusion. Therefore, in the stacked capacitor of the comparative example, noise signals flow in the same direction across all six capacitor elements. The noise suppression level is -84 dB for a 1 MHz noise signal and -87 dB for a 100 MHz noise signal.
[0113] As described above, the stacked capacitor of the embodiment exhibits significantly higher noise suppression compared to the stacked capacitor of the comparative example. Therefore, it can be said that the embodiment demonstrates superiority.
[0114] This invention can be implemented in various other forms without departing from its spirit or main features. Therefore, the above-described embodiments are merely illustrative in all respects and should not be interpreted as limiting. The scope of this invention is defined by the claims and is not limited by the text of the specification. Furthermore, all modifications and alterations falling within the equivalent scope of the claims are within the scope of this invention.
[0115] This application claims priority based on Japanese Patent Application No. 2024-005653, filed January 17, 2024. The contents of that application are incorporated herein by reference. Furthermore, all documents cited in this specification are incorporated herein by reference in their entirety.
[0116] Industrial availability
[0117] This disclosure can be used in multilayer capacitors.
[0118] Explanation of reference numerals in the attached figures
[0119] 10: Multilayer capacitors
[0120] 20: First capacitor element
[0121] 21: First anode body (anode body)
[0122] 21a: Part One
[0123] 21b: Part Two
[0124] 22: First cathode section (cathode section)
[0125] 23: First dielectric layer (dielectric layer)
[0126] 24: First Insulation Section
[0127] 30: Second capacitor element
[0128] 31: Second anode body (anode body)
[0129] 31a: Part Three
[0130] 31b: Part Four
[0131] 32: Second cathode section (cathode section)
[0132] 33: Second dielectric layer (dielectric layer)
[0133] 34: Second Insulation Section
[0134] 40: Conductive paste
[0135] 51: First anode terminal
[0136] 52: Second anode terminal
[0137] 53: Third anode terminal
[0138] 60: Cathode terminal
[0139] 60a: Facial installation
[0140] 60b: Side wall portion
[0141] 70: Exterior body
[0142] C: Cathode body
Claims
1. A multilayer capacitor comprising: a first capacitor element having an anode body, a cathode portion, and a dielectric layer disposed between the anode body and the cathode portion, and stacked thereon; and a second capacitor element. The anode body of the first capacitor element has: The first part protrudes from the cathode portion in a region on one side in a first direction; and The second part protrudes from the cathode portion in the region on the other side of the first direction. The anode body of the second capacitor element has: The third part protrudes from the cathode portion in the region on one side of the first direction; and The fourth part, in the region on the other side of the first direction, protrudes from the cathode portion. The stacked capacitor comprises: The first anode terminal is electrically connected to the first portion of the first capacitor element; The second anode terminal is electrically connected to the third portion of the second capacitor element; as well as The cathode terminal is electrically connected to the cathode portion of the first capacitor element and the second capacitor element. The second part is electrically connected to the fourth part.
2. The multilayer capacitor according to claim 1, comprising: The third anode terminal is electrically connected to the second portion of the first capacitor element and the fourth portion of the second capacitor element.
3. The stacked capacitor according to claim 1 or 2, wherein, The first portion protrudes from the cathode portion of the first capacitor element toward one side in the first direction. The second portion protrudes from the cathode portion of the first capacitor element to the other side in the first direction. The third portion protrudes from the cathode portion of the second capacitor element toward one side in the first direction. The fourth portion protrudes from the cathode portion of the second capacitor element to the other side in the first direction.
4. The stacked capacitor according to claim 1 or 2, wherein, At least one of the first portion and the second portion protrudes from the cathode portion of the first capacitor element in a second direction.
5. The stacked capacitor according to claim 1 or 2, wherein, The cathode terminal has: The mounting face is disposed at one end of the stacking direction of the first capacitor element and the second capacitor element; as well as The sidewall portion rises continuously from the mounting surface and is electrically connected to the side of the cathode portion of each of the first capacitor element and the second capacitor element.
6. The stacked capacitor according to claim 1 or 2, wherein, The first capacitor element and the second capacitor element have a conductive polymer layer covering at least a portion of the dielectric layer, or have a ceramic layer constituting the dielectric layer.
7. The stacked capacitor according to claim 1 or 2, wherein, At least a plurality of the second capacitor elements are provided.
8. The multilayer capacitor according to claim 7, wherein, The first capacitor element is stacked alternately with the plurality of second capacitor elements.
9. The stacked capacitor according to claim 7, wherein, The cathode terminal has a mounting surface disposed at one end in the stacking direction of the first capacitor element and the second capacitor element. The plurality of second capacitor elements are stacked together on the mounting surface side. The first capacitor element is stacked on the opposite side of the mounting surface.