CN116997983A - Solid electrolytic capacitor - Google Patents
Solid electrolytic capacitor Download PDFInfo
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- CN116997983A CN116997983A CN202280019924.9A CN202280019924A CN116997983A CN 116997983 A CN116997983 A CN 116997983A CN 202280019924 A CN202280019924 A CN 202280019924A CN 116997983 A CN116997983 A CN 116997983A
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- solid electrolytic
- electrolytic capacitor
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- Fixed Capacitors And Capacitor Manufacturing Machines (AREA)
Abstract
A solid electrolytic capacitor having high heat resistance is provided by using a solid electrolytic capacitor comprising: at least 1 capacitor element including an anode portion and a cathode portion; an anode lead terminal; a cathode lead terminal; and an exterior body covering the capacitor element, the anode lead terminal and the cathode lead terminal each having a main surface and a side surface, and including an embedded portion embedded in the exterior body and an exposed portion exposed from the exterior body, at least a part of the main surface of the exposed portion being covered with a low melting point material in at least one of the anode lead terminal and the cathode lead terminal, and a 1 st side surface region of the side surface of the embedded portion, which is greater than 0.36mm from a boundary of the embedded portion and the exposed portion, being uncovered with the low melting point material.
Description
Technical Field
The present disclosure relates to solid electrolytic capacitors.
Background
Solid electrolytic capacitors are mounted in various electronic devices. The solid electrolytic capacitor generally includes an anode lead terminal and a cathode lead terminal electrically connected to the capacitor element, and an exterior body covering the capacitor element.
Patent document 1 discloses a chip-type solid electrolytic capacitor comprising a solid electrolytic capacitor element including an anode body including a valve metal from which an anode lead is drawn, an oxide film formed on a surface of the anode body, a solid electrolyte layer formed on the oxide film, and a cathode lead layer including a graphite layer and a silver paste layer formed on the solid electrolyte layer, wherein a first plating layer serving as a base is formed on an entire surface of both surfaces of a plate-shaped lead frame terminal and the cathode lead layer is connected to the plate-shaped lead frame terminal by a conductive adhesive, and a second plating layer including a noble metal is formed only on a surface of the first plating layer in contact with the conductive adhesive (see fig. 1).
Prior art literature
Patent literature
Patent document 1: japanese patent application laid-open No. 2010-67876
Disclosure of Invention
The solid electrolytic capacitor of one aspect of the present disclosure includes: at least 1 capacitor element including an anode portion and a cathode portion; an anode lead terminal having an anode connection surface electrically connected to the anode portion; a cathode lead terminal having a cathode connection surface electrically connected to the cathode portion; and an exterior body covering the capacitor element, wherein the anode lead terminal and the cathode lead terminal include: the anode and cathode connection surfaces are formed of a material having a low melting point, and the side surfaces of the embedded portion are not covered with the material having a low melting point, at least a 1 st side surface region of the embedded portion, which is greater than 0.36mm from a boundary between the embedded portion and the exposed portion.
The general or specific aspects of the present disclosure may also be realized by solid electrolytic capacitors, devices and systems incorporating the same, methods of using the same, or any combination thereof.
According to the present disclosure, a solid electrolytic capacitor having high heat resistance can be realized.
Drawings
Fig. 1 is a cross-sectional view schematically showing the constitution of an example of a solid electrolytic capacitor of the present disclosure.
Fig. 2 is a perspective view schematically showing the structure of a main part of the solid electrolytic capacitor shown in fig. 1.
Fig. 3 is a plan view (a) and a side view (B) schematically showing a cathode lead terminal of a main portion of the solid electrolytic capacitor shown in fig. 2.
Fig. 4 is a cross-sectional view schematically showing the constitution of another example of the solid electrolytic capacitor of the present disclosure.
Fig. 5 is a cross-sectional view schematically showing the constitution of still another example of the solid electrolytic capacitor of the present disclosure.
Detailed Description
Before explaining the embodiments, the problems in the prior art will be briefly described below.
Patent document 1 proposes the above-described chip-type solid electrolytic capacitor in which a tin plating layer is formed on a first plating layer only in at least a part of a portion of a lead frame where the second plating layer is not formed on the same surface as the surface on which the second plating layer is formed (see fig. 2). Patent document 1 proposes the above-described chip-type solid electrolytic capacitor in which a tin plating layer is formed on the first plating layer on at least a part of the back surface of the lead frame on which the second plating layer is formed (see fig. 3).
However, as shown in fig. 2 and 3 of patent document 1, when a low-melting-point material such as a tin plating layer exists in the region of the lead frames 24 and 34 that is in contact with the exterior resin 2, the low-melting-point material melts and moves to segregate when the solid electrolytic capacitor is heated at a high temperature (for example, when mounted on a substrate), and a gap may occur between the lead frames 24 and 34 and the exterior resin 2. As a result, the inside of the solid electrolytic capacitor is easily communicated with the external environment, and the solid electrolytic capacitor is easily deteriorated.
In view of the above problems, the present disclosure can realize a solid electrolytic capacitor having high heat resistance.
The embodiments of the present disclosure will be described below by way of example, but the present disclosure is not limited to the examples described below. In the following description, specific values and materials are sometimes illustrated, but other values and materials may be applied as long as the effects of the present disclosure can be obtained. Among the constituent elements other than the characteristic portions in the present disclosure, the constituent elements of a known solid electrolytic capacitor may be applied. In this specification, in the case of being referred to as "a range of values a to B", the range includes the value a and the value B.
The solid electrolytic capacitor according to one embodiment of the present disclosure includes: at least 1 capacitor element including an anode portion and a cathode portion; an anode lead terminal having an anode connection surface electrically connected to the anode portion; a cathode lead terminal having a cathode connection surface electrically connected to the cathode portion; and an exterior body covering the capacitor element.
The anode lead terminal and the cathode lead terminal have: the anode and cathode connection surfaces are provided with a main surface and a side surface intersecting the main surface, respectively, and each of the anode and cathode connection surfaces includes an embedded portion embedded in the exterior body and an exposed portion exposed from the exterior body.
The principal surface is divided into a front surface and a back surface (here, principal surface a and principal surface B on the opposite side thereof). The side surface is a surface extending in accordance with a contour line when the lead terminal is viewed from a normal direction of the main surface, and is a surface having a linear minute area with a width corresponding to a thickness of the lead terminal. However, attention is paid here to the side surfaces extending over the buried portion and the exposed portion. Such sides are also divided into one side and the other (here side a and side B on the opposite side thereof).
That is, in general, there are 2 side regions 1 and 2 side regions, respectively, and 2 main surface regions 1 and 2 main surface regions 2, respectively. In the present embodiment, the following condition A, B and other conditions are intended to be satisfied in each of the 1 st side surface region and the 1 st main surface region. The conditions to be satisfied by the 2 nd side surface region and the 2 nd main surface region described later are intended to be satisfied in each of the 2 nd side surface region and the 2 nd main surface region.
At least one lead terminal selected from the anode lead terminal and the cathode lead terminal (hereinafter, also referred to as "lead terminal a"), at least a part of the main surface of the exposed portion is covered with a low-melting-point material.
On the other hand, the embedded portion of the lead terminal a satisfies the following condition a.
< condition A >
At least a 1 st side surface region of the lead terminal A, which is greater than 0.36mm from the boundary between the embedded portion and the exposed portion, is not covered with a low melting point material. The 1 st side area is an area having a distance from the boundary along the extension of the lead terminal a of more than 0.36 mm.
In addition, the lead terminal a preferably satisfies the following condition B.
< condition B >
At least a 1 st main surface region of the embedded portion and the exposed portion, which is greater than 0.15mm from the boundary of the embedded portion, is not covered with the low melting point material. The 1 st main surface region is a region having a distance from the boundary along the extension of the lead terminal a of more than 0.15 mm.
Here, the distance from the boundary along the extension of the lead terminal a can be measured by cross-sectional observation parallel to the extension direction of the lead terminal a of the solid electrolytic capacitor. In such a cross section, the distance limiting the 1 st side area is determined by the length of the center line of the side face of the lead terminal a. The distance limiting the 1 st main surface area is determined by the length of the line drawn by the main surface of the lead terminal a. Hereinafter, the distances from the boundary are explained as the same.
The term "not covered with the low-melting-point material" means not only not covered with the same material as the low-melting-point material (hereinafter, also referred to as "low-melting-point material a") covering at least a part of the main surface of the exposed portion, but also not covered with a low-melting-point material other than the low-melting-point material a.
The side surface of the buried portion can be conceptually divided into a 1 st side surface region and a 2 nd side surface region which is the remainder other than the 1 st side surface region. The 1 st side surface region is a region greater than 0.36mm from the boundary between the embedded portion and the exposed portion. The 2 nd side surface region is a region having a distance of 0.36mm or less from the boundary between the embedded portion and the exposed portion. The 1 st side area is continuous with the 2 nd side area.
In the case where the condition a is satisfied, regarding the low melting point material, the 2 nd side surface region in the side surface of the buried portion is allowed to be covered with the low melting point material. However, the region that can be covered with the low-melting-point material is preferably limited to a region of the 2 nd side surface region having a distance of 0.25mm or less from the boundary between the buried portion and the exposed portion, more preferably 90% or more of the area of the 2 nd side surface region is not covered with the low-melting-point material, and still more preferably the 2 nd side surface region is not covered with the low-melting-point material at all.
If the 1 st side surface region of the side surface of the embedded portion is covered with the low melting point material, when the solid electrolytic capacitor is heated at a high temperature (for example, when it is mounted on a substrate), the low melting point material melts, and the side surface of the embedded portion moves downward in the vertical direction and segregates, and a gap may occur between the embedded portion and the exterior body. In contrast, when at least the 1 st side surface region of the side surface of the embedded portion is not covered with the low melting point material, a gap is less likely to occur between the embedded portion and the exterior body. Even if a gap is generated, the distance from the boundary between the embedded portion and the exposed portion is limited to a range of 0.36mm or less. Therefore, the inside of the solid electrolytic capacitor is not easily communicated with the external environment, and deterioration of the solid electrolytic capacitor is suppressed. For example, deterioration of the conductive polymer contained in the solid electrolyte layer can be suppressed, and reduction of the electrostatic capacitance can be suppressed. In addition, an increase in ESR can be suppressed.
The main surface of the buried portion can be conceptually divided into a 1 st main surface region and a 2 nd main surface region which is the remainder other than the 1 st main surface region. The 1 st main surface region is a region greater than 0.15mm from the boundary between the embedded portion and the exposed portion. The 2 nd main surface region is a region having a distance of 0.15mm or less from the boundary between the embedded portion and the exposed portion. The 1 st main surface area is continuous with the 2 nd main surface area.
When the condition B is satisfied, the 2 nd main surface region of the main surface of the buried portion is allowed to be covered with the low melting point material. However, the region that can be covered with the low-melting-point material is preferably limited to a region in the 2 nd main surface region in which the distance from the boundary between the embedded portion and the exposed portion is 0.1mm or less or 0.05mm or less, more preferably 90% or more of the area of the 2 nd main surface region is not covered with the low-melting-point material, and still more preferably the 2 nd main surface region is not covered with the low-melting-point material at all.
If the 1 st main surface area of the main surface of the embedded portion is covered with the low melting point material, when the solid electrolytic capacitor is heated at a high temperature (for example, when it is mounted on a substrate), the low melting point material may be melted, and a part of the low melting point material that has flowed may segregate toward the exposed portion side of the embedded portion. As a result, a gap may be generated between the embedded portion and the exterior body. In contrast, when at least the 1 st main surface area of the main surface of the embedded portion is not covered with the low melting point material, a gap is less likely to occur between the embedded portion and the exterior body. Even if a gap is generated, the distance from the boundary between the embedded portion and the exposed portion is limited to a range of 0.15mm or less. Therefore, the inside of the solid electrolytic capacitor is not easily communicated with the external environment, and deterioration of the solid electrolytic capacitor is suppressed.
The movement and segregation of the melted low-melting-point material are easily promoted by the action of gravity on the side surface of the embedded portion. Therefore, the lead terminal a needs to satisfy at least the condition a. In other words, even when only the condition a is satisfied in the lead terminal a, a corresponding improvement in heat resistance can be expected. However, it is preferable that the lead terminal a satisfies both the condition a and the condition B.
In addition, in at least one of the anode lead terminal and the cathode lead terminal, if at least a part of the main surface of the exposed portion is covered with a low melting point material and condition a (preferably, conditions a and B) is satisfied, a corresponding improvement in heat resistance can be expected. However, from the viewpoint of greatly improving heat resistance, it is preferable that at least a part of the main surface of the exposed portion is covered with a low melting point material in both the anode lead terminal and the cathode lead terminal, and condition a (preferably, conditions a and B) is satisfied.
In general, in a solid electrolytic capacitor, the distance between the external environment and the cathode portion is shorter than the distance between the external environment and the anode portion. Therefore, in the case where at least a part of the main surface of the exposed portion of the cathode lead terminal is covered with the low-melting-point material, the cathode lead terminal preferably satisfies the condition a (preferably both the conditions a and B) from the viewpoint of more reliably improving the heat resistance.
In the lead terminal a, the side surface of the exposed portion may not be covered with the low melting point material. By designing the lead terminal in this way, it is possible to more reliably and easily realize a mode in which the 1 st side surface region and the 2 nd side surface region are not covered with the low melting point material.
Hereinafter, a case where the side surface of the exposed portion is not covered with the low melting point material is defined as condition C. At least one of the anode lead terminal and the cathode lead terminal may satisfy the condition C, but from the viewpoint of more reliably improving the heat resistance, it is preferable that at least the cathode lead terminal satisfies the condition C, or that both the anode lead terminal and the cathode lead terminal satisfy the condition C.
The main surface of the exposed portion is divided into a main surface a on the side to which the connection electrode included in the component such as the circuit board is connected and a main surface B on the opposite side. As long as at least a part of the area of the main surface a is covered with the low melting point material. The main surface B may be entirely uncovered by the low-melting-point material, or at least a part of the area of the main surface B may be covered by the low-melting-point material.
The method for attaching the low-melting-point material to the metal foil is not particularly limited, and liquid phase methods such as electrolytic plating and electroless plating, and vapor phase methods such as vapor deposition can be used.
(lead terminal)
The lead terminals are also called lead frames or the like. The shape of each of the anode lead terminal and the cathode lead terminal is not particularly limited as long as it has a main surface and a side surface intersecting the main surface. The anode lead terminal and the cathode lead terminal are each formed by cutting a starting material (typically, a metal foil) into a predetermined shape, for example. When the starting material is a metal foil, the main surface comes from both front and back surfaces of the metal foil, and the side surfaces are formed by cutting when the metal foil is cut into a predetermined shape.
The anode connection surface is provided on at least the main surface of the anode lead terminal. The cathode connection surface is provided on at least the main surface of the cathode lead terminal. The anode connecting surface is electrically connected to the anode portion by physical contact, adhesion or bonding by conductive adhesive or solder, soldering, or the like. The cathode connection surface may be electrically connected to the cathode portion by physical contact, conductive adhesive, soldering, or the like. The physical contact includes a contact accompanied by deformation of the lead terminal caused by pressure of caulking or the like. The conductive adhesive is, for example, a mixture of a resin and conductive particles. The resin may be a curable resin. The conductive particles may be carbon particles, metal particles, or the like.
A portion of the anode lead terminal adjacent to the anode portion is buried in the exterior body together with the anode portion, and a portion of the cathode lead terminal adjacent to the cathode portion is buried in the exterior body together with the cathode portion. The remaining portions of the anode lead terminal and the cathode lead terminal are led out of the exterior body. Accordingly, the anode lead terminal and the cathode lead terminal each include an embedded portion embedded in the exterior body and an exposed portion exposed from the exterior body. The exposed portions of the anode lead terminal and the cathode lead terminal function as external electrodes for connecting the solid electrolytic capacitor to the connection electrode provided in the circuit board or the like.
The starting material of the lead terminal (and the material of the lead terminal after forming the lead terminal) is not particularly limited as long as it is electrochemically and chemically stable and has conductivity, but a metal foil is generally used. From the viewpoint of thickness reduction, the thickness of the lead terminal (distance between the main surfaces of the metal foil) is, for example, 25 μm or more and 200 μm or less, and 25 μm or more and 100 μm or less.
The lead terminal satisfying the above condition C is obtained by, for example, attaching a low-melting-point material to a starting material (typically, a metal foil) of the lead terminal in a state where the embedded portion is shielded by a shielding material such as a shielding tape, and then cutting the starting material into a predetermined shape. In other words, the lead terminal satisfying the condition C is obtained by a method of forming the side surfaces of the embedded portion and the exposed portion after attaching the low melting point material to the starting material (typically, a metal foil) of the lead terminal.
The main surface of at least one of the anode lead terminal and the cathode lead terminal may be roughened. This improves adhesion between the lead terminal and the exterior body, and makes it less likely that the inside of the solid electrolytic capacitor is in communication with the external environment.
The roughened main surface (roughened surface) may be provided on at least a part of the main surface of the embedded portion of at least one of the anode lead terminal and the cathode lead terminal. The proportion of the roughened surface in the entire area of the main surface of the buried portion may be 50% or more, 80% or more, or 90% or more, for example. The roughened surface may be formed so as to span from the buried portion to the exposed portion, and may be formed on at least a part of the main surface of the exposed portion.
The roughening can be performed by, for example, a sand blasting method, a roughening plating method, a roughening etching method, or the like. The blasting method is preferable in terms of rapid processing and excellent cost performance. The roughening plating method is preferable in terms of low cost. The roughening etching method is preferable in that unevenness is small and fine roughness can be formed. In addition, unlike the sand blast method, the roughening plating method and the roughening etching method have an advantage of not leaving beads (projection material).
The spread interface area ratio (Sdr) of the roughened main surface (roughened surface) may be, for example, 0.4 or more. Here, the expansion interface area ratio refers to a parameter measured according to ISO 25178. When the Sdr is 0.4 or more, the adhesion between the lead terminal and the exterior body is further improved, and the inside of the solid electrolytic capacitor is less likely to communicate with the external environment.
There is no particular upper limit on the expansion interface area ratio, but by setting the expansion interface area ratio to a certain value or less, the lead terminal can be easily manufactured. The ratio of the area of the developed interface of the roughened surface may be 10.0 or less, 6.0 or less, 4.0 or less, 2.0 or less, 1.0 or less, or 0.6 or less. The spreading interface area ratio may be in the range of 0.4 to 10.0, 0.4 to 6.0, 0.4 to 4.0, 0.4 to 2.0, 0.4 to 1.0, or 0.4 to 0.6.
In the blasting method, for example, by reducing the particle diameter (for example, increasing the number) of particles (projection material), the spread area ratio of the roughened surface can be increased to 0.4 or more. In addition, by increasing the number of shots of blasting, the spread interface area ratio of the roughened surface subjected to blasting can be increased. The particles (projection material) used for blasting are not particularly limited, and alumina particles and garnet particles can be used.
When the roughened surface is formed by the roughening plating method, for example, needle-shaped or particle-shaped plating can be used to increase the surface area, so that the Sdr can be 0.4 or more. For example, the ratio of needle-like or particle-like plating may be increased.
In the case of forming the roughened surface by the roughening etching method, for example, by forming the roughened shape by utilizing the difference between the etching rate of the grain boundary and the etching rate of the crystal grain (the etching rate of the grain boundary is high), the surface area can be increased, and as a result, the Sdr can be made to be 0.4 or more. For example, the ratio of grain boundaries to crystal grains in a metal constituting a starting material of the lead terminal may be changed by selecting the metal, or the difference in etching rate may be changed by changing etching conditions.
(Low melting Material)
The low-melting point material is widely included as a material that melts by heating (for example, when mounting the solid electrolytic capacitor on a substrate) when the solid electrolytic capacitor is assembled as a component in an arbitrary device. The melting point of the low melting point material may be, for example, 180℃to 240 ℃. The low-melting-point material covering at least a part of the main surface of the exposed portion melts when connecting the connection electrode of the component such as the circuit board and the exposed portion (external electrode), thereby facilitating the connection of the two.
The low melting point material may be provided with tin (Sn) or solder. In this case, at least a part of the exposed portion is bonded to the connection electrode as an external electrode via tin or solder. The bonding via such metallic materials is stable.
Examples of the solder include materials specified in JIS Z3282-1999. In particular, the method comprises the steps of, examples thereof include lead-containing solders such as Sn-Pb, pb-Sn, sn-Pb-Sb, sn-Pb-Bi, sn-Pb-Cd, sn-Pb-Cu, sn-Pb-Ag, pb-Ag-Sn and the like; lead-free solders such as Sn-Sb, sn-Bi, sn-Cu-Ag, sn-In-Ag-Bi, sn-Ag-Cu, sn-Ag-Bi-Cu, sn-Zn, sn-Bi-Zn, and the like.
The low melting point material is applied to at least the exposed portion of the lead terminal, for example, in the form of a layer or film having a thickness of 5 μm to 20 μm. In the case where the low melting point material is Sn or solder, for example, a plating layer of the low melting point material having the above thickness may be formed at least at the exposed portion of the lead terminal. The thickness of the low-melting-point material on the main surface of the exposed portion may be determined, for example, as an average value of values measured at arbitrary 5 points.
(outer package)
The exterior body seals the capacitor element, the embedded portion of the anode lead terminal, and the embedded portion of the cathode lead terminal so that the capacitor element is not exposed to the outside. The exterior body also insulates the anode lead terminal from the cathode lead terminal. The exterior body may be formed of a known material and composition used for a solid electrolytic capacitor. The exterior body can be formed using, for example, an insulating thermosetting resin composition. The thermosetting resin composition may contain a thermosetting resin and may contain an additive. As the additive, an inorganic filler or the like may be contained. As the thermosetting resin, epoxy resin, phenolic resin, silicone resin, melamine resin, urea resin, alkyd resin, polyurethane, polyimide, unsaturated polyester, and the like can be included. The thermosetting resin composition is formed by a molding method such as transfer molding to seal the capacitor element, the embedded portion of the anode lead terminal, and the embedded portion of the cathode lead terminal.
(capacitor element)
The capacitor element has an anode portion and a cathode portion. The dielectric layer is interposed between the anode portion and the cathode portion. The anode portion includes an anode body. The cathode portion is provided so as to cover a dielectric layer formed on at least a part of the surface of the anode body.
The anode body comprises a valve metal-containing metal foil or a porous sintered body containing a valve metal. The anode body comprising the metal foil is for example sheet-like or plate-like. The surface of the metal foil is typically roughened. The anode body including the porous sintered body is not particularly limited, and is generally rectangular or prismatic. The anode body including the porous sintered body may have anode wires vertically disposed on the porous sintered body. The anode wire is used for connection with the anode lead terminal. The thickness of the anode body including the metal foil is not particularly limited, and is, for example, 15 μm or more and 300 μm or less. The thickness of the anode body including the porous sintered body is not particularly limited, and is, for example, 15 μm or more and 5mm or less.
Examples of the valve metal include aluminum, tantalum, titanium, and niobium. The anode body may contain 1 or 2 or more valve metal.
(dielectric layer)
The dielectric layer is formed by, for example, anodizing the surface of the anode body by chemical conversion treatment or the like. Thus, the dielectric layer may comprise an oxide of the valve action metal. For example, in the case of using aluminum as the valve action metal, the dielectric layer may contain Al 2 O 3 . However, the dielectric layer is not particularly limited as long as it is a material functioning as a dielectric.
(cathode portion)
The cathode portion has, for example, a solid electrolyte layer covering at least a part of the dielectric layer and a cathode lead-out layer covering at least a part of the solid electrolyte layer. The solid electrolyte layer may be formed of, for example, a manganese compound, a conductive polymer, or the like.
As the conductive polymer, polypyrrole, polyaniline, polythiophene, polyacetylene, derivatives thereof, and the like can be used. The solid electrolyte layer containing a conductive polymer is formed, for example, by chemically polymerizing and/or electrolytically polymerizing a raw material monomer on the dielectric layer. Alternatively, the conductive polymer may be formed by applying a solution in which the conductive polymer is dissolved or a dispersion in which the conductive polymer is dispersed to the dielectric layer.
The cathode lead layer is formed so as to cover at least a part of the solid electrolyte layer. The cathode lead layer includes, for example, a carbon layer and a metal paste layer (for example, a silver paste layer) formed on the surface of the carbon layer. The carbon layer is composed of a composition containing a conductive carbon material such as graphite. The metal paste layer is composed of, for example, a composition containing silver particles and a binder resin. However, the structure of the cathode extraction layer is not particularly limited as long as it has a current collecting function.
An example of the solid electrolytic capacitor of the present disclosure will be specifically described below with reference to the drawings. The above-described components can be applied to the components of the electrolytic capacitor of one example described below. The components of the electrolytic capacitor of one example described below may be modified based on the above description. The matters described below can also be applied to the above-described embodiments. In the embodiments described below, unnecessary components in the electrolytic capacitor of the present disclosure may be omitted.
The embedded portion of the cathode lead terminal may have a guide portion that stands up from the cathode connection surface to limit the position of the capacitor element. For example, at least one guide portion may be provided from each of both ends of the cathode connection surface in a direction orthogonal to a direction from the anode lead terminal toward the cathode lead terminal.
In the case where the solid electrolytic capacitor has a plurality of stacked capacitor elements, the embedded portion may have element mounting portions adjacent to 1 of the capacitor elements disposed outermost in at least one of the anode lead terminal and the cathode lead terminal. In this case, the guide portion may be provided so as to stand only on one side of the main surface a side and the main surface B side of the embedded portion on which the capacitor element is mounted.
Fig. 1 is a cross-sectional view schematically showing the configuration of one example of a solid electrolytic capacitor 100 of the present disclosure. The solid electrolytic capacitor 100 includes: at least 1 capacitor element 110 including an anode portion 111 and a cathode portion 112; an anode lead terminal 120 having an anode connection surface 121A electrically connected to the anode portion 111; a cathode lead terminal 130 having a cathode connection surface electrically connected to the cathode portion 112; and an exterior body 140 covering the capacitor element 110. The cathode lead terminal 130 has an element mounting portion 131A adjacent to the outermost 1 capacitor element.
The solid electrolytic capacitor 100 has a plurality of stacked capacitor elements 110. The anode portion 111 includes an anode body including a metal foil having a roughened surface, and the metal foil includes a valve metal. Therefore, the anode portion 111 is in a sheet or plate shape.
The anode lead terminal 120 and the cathode lead terminal 130 have: a main surface having an anode connection surface 121A and a cathode connection surface, and a side surface intersecting the main surface. The anode lead terminal 120 includes an embedded portion 120A embedded in the exterior body 140 and an exposed portion 120B exposed from the exterior body 140. The cathode lead terminal 130 includes an embedded portion 130A embedded in the exterior body 140 and an exposed portion 130B exposed from the exterior body 140. The anode lead terminal 120 and the cathode lead terminal 130 are led out from the side surfaces of the solid electrolytic capacitor.
The main surface of the exposed portion of at least one of the anode lead terminal 120 and the cathode lead terminal 130 is covered with a low melting point material.
The embedded portion 130A of the cathode lead terminal 130 has an element mounting portion 131A adjacent to the 1 capacitor element 110 disposed on the outermost side. At least a part of the element mounting portion 131A is a cathode connection surface. The element mounting portion 131A has a guide portion 132A that stands up from the cathode connection surface to limit the position of the capacitor element 110.
The anode connection surface 121A of the embedded portion 120A of the anode lead terminal 120 is connected to the anode portion 111 by, for example, welding. The cathode connection surface (element mounting portion 131A) of the embedded portion 130A of the cathode lead terminal 130 is connected to the cathode portion 112 via, for example, a conductive adhesive.
The guide portions 132A are provided 1 at each of both ends of the cathode connection surface in a direction orthogonal to the direction from the anode lead terminal 120 toward the cathode lead terminal 130. The guide portion 132A is provided to stand only on one principal surface side on which the capacitor element 110 is mounted.
Fig. 2 is a perspective view schematically showing the structure of a main part of the solid electrolytic capacitor 100 shown in fig. 1. Fig. 3 is a plan view (a) and a side view (B) schematically showing a cathode lead terminal 130 of a main portion of the solid electrolytic capacitor 100 shown in fig. 2. In fig. 2, an embedded portion 130A of the cathode lead terminal 130 embedded in the exterior body 140 is shown by a broken line.
The side surface of the embedded portion 130A of the cathode lead terminal 130 is divided into a 1 st side surface region 133A having a distance of more than 0.36mm from the boundary 130C between the embedded portion 130A and the exposed portion 130B and a 2 nd side surface region 134A having a distance of 0.36mm or less from the boundary 130C.
The main surface of the embedded portion 130A of the cathode lead terminal 130 is divided into a 1 st main surface region 135A having a distance of more than 0.15mm from the boundary 130C between the embedded portion 130A and the exposed portion 130B, and a 2 nd main surface region 136A having a distance of 0.15mm or less from the boundary 130C.
The 1 st side surface region 133A may be not covered with the low melting point material, but it is preferable that both the 1 st side surface region 133A and the 1 st main surface region 135A are not covered with the low melting point material.
Both the 2 nd side surface region 134A and the 2 nd main surface region 136A are allowed to be covered with a low melting point material, but from the viewpoint of reliably improving the heat resistance of the solid electrolytic capacitor, it is preferable that at least one of the 2 nd side surface region 134A and the 2 nd main surface region 136A is not covered with a low melting point material, and it is more preferable that both the 2 nd side surface region 134A and the 2 nd main surface region 136A are not covered with a low melting point material.
The side 137B of the exposed portion 130B of the cathode lead terminal 130 is allowed to be covered with the low melting point material, but it is preferable that the side 137B is not covered with the low melting point material. This can further reliably improve the heat resistance of the solid electrolytic capacitor.
The main surface 138B of the exposed portion 130B of the cathode lead terminal 130 may be covered with a low-melting-point material at least in a region connected to the connection electrode on the main surface on the side connected to the connection electrode included in a component such as a circuit board. In view of easy mounting on a substrate and firm bonding to a connecting electrode, it is preferable that 90% or more (for example, 100%) of the area of the main surface 138B is covered with a low melting point material.
In the case where the solid electrolytic capacitor has a plurality of stacked capacitor elements, the buried portion may have a clamped portion interposed between 21 st and 2 nd elements adjacent to each other selected from the plurality of capacitor elements in at least one of the anode lead terminal and the cathode lead terminal. In this case, the guide portions may be provided to stand on both the main surface a side and the main surface B side of the embedded portion.
Fig. 4 is a sectional view schematically showing the constitution of another solid electrolytic capacitor 100A of the present disclosure. The solid electrolytic capacitor 100A has the same capacitor element 110 as the solid electrolytic capacitor 100. On the other hand, the structures of the anode lead terminal 120 and the cathode lead terminal 130 are different from those of the solid electrolytic capacitor 100. The anode connection surface 121A of the embedded portion 120A of the anode lead terminal 120 is electrically connected to the anode portion 111 by physical contact. Here, the anode portions 111 of the plurality of capacitor elements are sandwiched by a part of the embedded portion 120A of the anode lead terminal 120 in a laminated state, and are caulked to the anode connection surface 121A. The anode lead terminal 120 and the cathode lead terminal 130 are led out from the bottom surface (lower side in fig. 4) of the solid electrolytic capacitor.
Fig. 5 is a cross-sectional view schematically showing the structure of still another solid electrolytic capacitor 100B of the present disclosure. The solid electrolytic capacitor 100B has the same capacitor element 110 as the solid electrolytic capacitor 100. On the other hand, the structures of the anode lead terminal 120 and the cathode lead terminal 130 are different from those of the solid electrolytic capacitor 100. The embedded portion 120A of the anode lead terminal 120 has a clamped portion 121A interposed between 21 st and 2 nd elements 110A and 110B adjacent to each other among the plurality of capacitor elements. The embedded portion 130A of the cathode lead terminal 130 has a clamped portion 131A interposed between the 1 st element 110A and the 2 nd element 110B.
At least a part of the clamped portion 121A is an anode connection surface. The anode connecting surface (clamped portion 121A) is connected to the anode portion 111 by welding, for example. At least a part of the clamped portion 131A is a cathode connection surface. The cathode connection surface (clamped portion 131A) is connected to the cathode portion 112 via, for example, a conductive adhesive.
The guide portions 132A are provided 2 at each of both ends of the cathode connection surface in a direction orthogonal to the direction from the anode lead terminal 120 toward the cathode lead terminal 130. The guide portions 132A are provided to stand up on the main surface side (main surface a side and main surface B side) of both the one side and the other side on which the capacitor element 110 is mounted.
Examples (example)
The present disclosure will be specifically described below based on examples and comparative examples, but the present disclosure is not limited to the following examples.
Examples 1 and 2 and comparative examples 1 and 2
A solid electrolytic capacitor having a laminate in which 6 capacitor elements were laminated was produced in the following manner.
(1) Manufacture of capacitor element
An aluminum foil (thickness 100 μm) was prepared as a base material, and the surface of the aluminum foil was subjected to etching treatment to obtain an anode body having a porous portion (thickness 35 μm on one principal surface side of the aluminum foil, thickness 35 μm on the other principal surface side). The anode body was immersed in a phosphoric acid solution (liquid temperature: 70 ℃) having a concentration of 0.3 mass%, and a direct current voltage of 10V was applied for 20 minutes, whereby alumina (Al) was formed on the surface of the anode body 2 O 3 ) Is formed on the substrate.
The anode body was divided into an anode portion, a cathode forming portion, and a separation portion therebetween, and a thin portion (thickness 35 μm) was formed by compressing a part of the separation portion by press working. An insulating resist tape (separating member) is attached to the thin portion.
The anode body having the dielectric layer formed thereon is immersed in a liquid composition containing a conductive material to form a precoat layer.
A polymerization solution containing pyrrole (a monomer of a conductive polymer), naphthalene sulfonic acid (a dopant), and water was prepared. The anode body having the dielectric layer and the precoat layer formed thereon was immersed in the resulting polymerization solution, and electrolytic polymerization was performed by applying a voltage of 3V to form a solid electrolyte layer.
The dispersion liquid obtained by dispersing graphite particles in water is applied to the solid electrolyte layer, and then dried to form a carbon layer on the surface of the solid electrolyte layer. Next, a silver paste containing silver particles and a binder resin (epoxy resin) was applied to the surface of the carbon layer, and then the binder resin was cured by heating, thereby forming a metal paste layer (silver paste layer, thickness 15 μm). Thus, a cathode lead layer composed of a carbon layer and a metal paste layer was formed, and a capacitor element was obtained.
The obtained 6 capacitor elements were laminated with a conductive paste interposed therebetween, and anode portions were joined to each other by laser welding, to obtain a laminate.
(2) Anode lead terminal and cathode lead terminal
Copper foil (thickness: 100 μm) for forming an anode lead terminal and a cathode lead terminal was prepared. Next, the copper foil is processed into a lead frame having a predetermined shape. The copper foil processed in the state before being singulated as a lead terminal is referred to as a lead frame herein. The lead frame is an aggregate of anode lead terminals and cathode lead terminals of a plurality of solid electrolytic capacitors. The embedded portion of the cathode lead terminal forms a component mounting portion that is adjacent to 1 of the outermost capacitor components and that mounts the laminate.
The portion of the lead frame which becomes the embedded portion of the anode lead terminal and the portion which becomes the embedded portion of the cathode lead terminal were masked with masking tape, and then a Sn plating layer (thickness: 10 μm) which is a low melting point material was formed at the portion which becomes the exposed portion. At this time, the portion to be the embedded portion of the anode lead terminal is strictly masked not only from the main surface of the embedded portion but also from the side surface so that the Sn-plated layer does not intrude into the 2 nd side surface region. On the other hand, the portion serving as the embedded portion of the cathode lead terminal is normally masked without strictly masking the side. Table 1 shows distances (Cd 1, cd 2) from the boundary between the embedded portion and the exposed portion of the cathode lead terminal to the embedded portion. Next, the portions to be embedded portions of the anode lead terminal and the cathode lead terminal were roughened by a sand blast method. The portions that become exposed portions of the anode lead terminal and the cathode lead terminal are not roughened. The developed interface area ratio Sdr of the roughened surface formed was 0.4 as measured according to ISO 25178.
In each table, each symbol is as follows. The distances were measured by observation of the cross section of the solid electrolytic capacitor with an electron microscope. In each table, negative values of Cd1, cd2, ad1, and Ad2 indicate that Sn does not reach the boundary between the buried portion and the exposed portion, and the value is a distance from the boundary to Sn covering the exposed portion.
Cd1: penetration distance of Sn from boundary between embedded part and exposed part in main surface of embedded part of cathode lead terminal
Cd2: penetration distance of Sn from boundary between embedded part and exposed part in side surface of embedded part of cathode lead terminal
Ad1: penetration distance of Sn from boundary between embedded part and exposed part in main surface of embedded part of anode lead terminal
Ad2: penetration distance of Sn from boundary between embedded part and exposed part in side surface of embedded part of anode lead terminal
Sdr: area ratio of the expanded interface
Rhm: failure rate of airtight seal
Resr: ESR failure rate
(3) Assembly of solid electrolytic capacitor
The stacked body of the capacitor element is connected to the element mounting portion of the embedded portion of the cathode lead terminal. At this time, the conductive paste was interposed between 1 cathode portion of the capacitor element disposed at the outermost side of the laminate and the cathode connection surface of the element mounting portion. On the other hand, the anode lead terminal is connected to the anode portion of the stacked body of the capacitor element.
Next, the capacitor element, the embedded portion of the anode lead terminal, and the embedded portion of the cathode lead terminal are sealed by transfer molding. Thus, 100 solid electrolytic capacitors A1, A2, B1, and B2 (rated voltage 2.5V) of the type shown in fig. 1 were each fabricated.
[ evaluation ]
(1) Failure rate of airtight seal
The solid electrolytic capacitors A1, A2, B1, B2 were heated under the same temperature conditions as the reflow process according to IPC/JEDEC J-STD-020D (heating at a maximum temperature of 260℃for 30 seconds). Then, the air tightness was evaluated by a total leakage test (japanese: sheath). Then, the capacitor having a pressure change greater than a predetermined value was judged to be defective in airtightness, and the defective rate (%) was determined. The results are shown in Table 1.
(2) ESR failure rate
The initial ESR values X0 (mΩ) of the solid electrolytic capacitors A1, A2, B1, and B2 at a frequency of 100kHz were measured using a 4-terminal LCR meter at 20 ℃. Next, a rated voltage was applied to the solid electrolytic capacitor at a temperature of 125 ℃ for 1000 hours (reliability test). Then, ESR value (X1) (mQ) was measured by the same method as described above. Then, the case where X1 is 2 times or more of X0 was determined as defective, and the defective rate (%). The results are shown in Table 1.
TABLE 1
| Cd1 | Cd2 | Sdr | Rhm(％) | Resr(％) | |
| A1 | -0.1mm | 0.25mm | 0.4 | 0％ | 0％ |
| A2 | -0.1mm | 0.36mm | 0.4 | 0％ | 0％ |
| B1 | -0.1mm | 0.44mm | 0.4 | 8％ | 4％ |
| B2 | 0mm | 0.40mm | 0.4 | 6％ | 4％ |
Examples 3 to 5
Masking of the portions of the main surface and the side surfaces that become the embedded portions of the cathode lead terminals was strictly performed, and Cd1 and Cd2 were set as shown in table 2. In the solid electrolytic capacitor A5 of example 5, the conditions of the sandblasting method were changed, and the lead terminal expansion area ratio Sdr was set to 0.6. Except for the above, solid electrolytic capacitors A3 to A5 were produced and evaluated in the same manner as in example 1. The results are shown in Table 2.
TABLE 2
| Cd1 | Cd2 | Sdr | Rhm(％) | Resr(％) | |
| A3 | -0.1mm | -0.1mm | 0.4 | 0％ | 0％ |
| A4 | 0mm | 0mm | 0.4 | 0％ | 0％ |
| A5 | 0mm | 0mm | 0.6 | 0％ | 0％ |
Examples 6 to 8
In the production of the lead frame, before the copper foil is processed into the lead frame having a predetermined shape, a portion to be the embedded portion of the anode lead terminal and a portion to be the embedded portion of the cathode lead terminal are masked with masking tape, and then a Sn plating layer is formed at the portion to be the exposed portion. Then, the copper foil is processed into a lead frame of a predetermined shape. The side surface of the portion to be embedded in the anode lead terminal and the side surface of the portion to be embedded in the cathode lead terminal are cut surfaces formed after the Sn plating layer is formed on the copper foil, and are therefore not covered with Sn at all. Except for the above, solid electrolytic capacitors A6 to A8 were produced and evaluated in the same manner as in examples 3 to 5. The results are shown in Table 3.
TABLE 3
| Cd1 | Cd2 | Sdr | Rhm(％) | Resr(％) | |
| A6 | -0.1mm | 0mm | 0.4 | 0％ | 0％ |
| A7 | 0mm | 0mm | 0.4 | 0％ | 0％ |
| A8 | 0mm | 0mm | 0.6 | 0％ | 0％ |
Examples 9 and 10 and comparative examples 3 to 5
In comparative examples 3 and 4, normal masking was performed at the portion to be the embedded portion of the cathode lead terminal, and Cd1 and Cd2 were changed as shown in table 4.
In examples 9 and 10 and comparative example 5, cd1 and Cd2 were changed as shown in table 4, in which not only the main surface but also the side surfaces were strictly masked at the portion to be the embedded portion of the cathode lead terminal.
Except for the above, solid electrolytic capacitors A9, a10, B3 to B5 were produced and evaluated in the same manner as in example 1. The results are shown in Table 4.
TABLE 4
| Cd1 | Cd2 | Sdr | Rhm(％) | Resr(％) | |
| B3 | 0.05mm | 0.52mm | 0.4 | 7％ | 6％ |
| B4 | 0.10mm | 0.73mm | 0.4 | 16％ | 15％ |
| A9 | 0.15mm | 0.15mm | 0.4 | 0％ | 0％ |
| A10 | 0.20mm | 0.20mm | 0.4 | 5％ | 3％ |
| B5 | 0.39mm | 0.39mm | 0.6 | 11％ | 9％ |
Example 11 and comparative example 6
Cd1 and Cd2 were changed as shown in table 5. In the solid electrolytic capacitor B7 of comparative example 7, the conditions of the sandblasting method were changed, and the lead terminal expansion area ratio Sdr was set to 0.3. Except for the above, solid electrolytic capacitors a11 and B6 were produced and evaluated in the same manner as in example 6. The results are shown in Table 5.
TABLE 5
| Gd1 | Cd2 | Sdr | Rhm(％) | Resr(％) | |
| A11 | 0.15mm | 0mm | 0.4 | 0％ | 0％ |
| B6 | 0.1mm | 0.73mm | 0.3 | 23％ | 21％ |
Examples 12 and 13 and comparative examples 7 and 8
In contrast to examples 1, 2 and comparative examples 1 and 2, the portion serving as the embedded portion of the cathode lead terminal was strictly masked not only on the main surface of the embedded portion but also on the side surface so that Sn plating did not intrude into the 2 nd side surface region. On the other hand, the portion to be the embedded portion of the anode lead terminal is normally masked without strict masking on the side surface. Except for the above, solid electrolytic capacitors a12, a13, B7, and B8 were produced and evaluated in the same manner as in examples 1 and 2 and comparative examples 1 and 2. The results are shown in Table 6.
TABLE 6
| Ad1 | Ad2 | Sdr | Rhm(％) | Resr(％) | |
| A12 | -0.1mm | 0.24mm | 0.4 | 0％ | 0％ |
| A13 | -0.1mm | 0.36mm | 0.4 | 0％ | 0％ |
| B7 | -0.1mm | 0.42mm | 0.4 | 6％ | 4％ |
| B8 | 0mm | 0.43mm | 0.4 | 5％ | 4％ |
Examples 14 to 16
Masking of the portions of the main surface and the side surfaces that become the embedded portions of the anode lead terminals was strictly performed, and Ad1 and Ad2 were as shown in table 7. In the solid electrolytic capacitor a16 of example 16, the conditions of the sandblasting method were changed, and the lead terminal expansion area ratio Sdr was set to 0.6. Except for the above, solid electrolytic capacitors a14 to a16 were produced and evaluated in the same manner as in example a 12. The results are shown in Table 7.
TABLE 7
| Ad1 | Ad2 | Sdr | Rhm(％) | Resr(％) | |
| A14 | -0.1mm | -0.1mm | 0.4 | 0％ | 0％ |
| A15 | 0mm | 0mm | 0.4 | 0％ | 0％ |
| A16 | 0mm | 0mm | 0.6 | 0％ | 0％ |
Examples 17 to 19
In the production of a lead frame, before a copper foil is processed into a lead frame having a predetermined shape, a portion to be an embedded portion of an anode lead terminal and a portion to be an embedded portion of a cathode lead terminal are masked with masking tape, then a Sn plating layer is formed on the portion to be an exposed portion, and then the copper foil is processed into the lead frame having the predetermined shape. Except for the above, solid electrolytic capacitors a17 to a19 were produced and evaluated in the same manner as in examples 14 to 16. The results are shown in Table 8.
TABLE 8
| Ad1 | Ad2 | Sdr | Rhm(％) | Resr(％) | |
| A17 | -0.1mm | 0mm | 0.4 | 0％ | 0％ |
| A18 | 0mm | 0mm | 0.4 | 0％ | 0％ |
| A19 | 0mm | 0mm | 0.6 | 0％ | 0％ |
Examples 20 and 21 and comparative examples 9 to 10
In comparative examples 9 and 10, normal masking was performed at a portion to be an embedded portion of the anode lead terminal, and Ad1 and Ad2 were changed as shown in table 9.
In examples 20 and 21, not only the main surface but also the side surfaces were strictly masked at the portions to be embedded portions of the anode lead terminals, and Ad1 and Ad2 were changed as shown in table 9.
Except for the above, solid electrolytic capacitors a20, 21, B9, and B10 were produced and evaluated in the same manner as in example 11. The results are shown in Table 9.
TABLE 9
| Ad1 | Ad2 | Sdr | Rhm(％) | Resr(％) | |
| B9 | 0.05nm | 0.48mm | 0.4 | 7％ | 6％ |
| B10 | 0.10mm | 0.71mm | 0.4 | 16％ | 15％ |
| A20 | 0.15mm | 0.16mm | 0.4 | 0％ | 0％ |
| A21 | 0.20mm | 0.22mm | 0.4 | 5％ | 3％ |
Example 22 and comparative example 11
Ad1 and Ad2 were changed as shown in table 10. In the solid electrolytic capacitor B11 of comparative example 11, the conditions of the sandblasting method were changed, and the lead terminal expansion area ratio Sdr was set to 0.3. Except for the above, solid electrolytic capacitors a22 and B11 were produced and evaluated in the same manner as in example 17. The results are shown in Table 10.
TABLE 10
| Ad1 | Ad2 | Sdr | Rhm(％) | Resr(％) | |
| A22 | 0.15mm | 0mm | 0.4 | 0％ | 0％ |
| B11 | 0.1mm | 0.71mm | 0.3 | 21％ | 20％ |
Industrial applicability
The solid electrolytic capacitor of the present disclosure has high heat resistance, and even when exposed to high temperatures, the inside of the solid electrolytic capacitor is not easily communicated with the external environment, and deterioration of the solid electrolyte layer is suppressed, so that the solid electrolytic capacitor can be used for various applications requiring heat resistance.
Description of the reference numerals
100. 100A, 100B solid electrolytic capacitor
110. Capacitor element
110A 1 st element
110B No. 2 element
111. Anode part
112. Cathode part
120. Anode lead terminal
Buried part of 120A anode lead terminal
Exposed portion of 120B anode lead terminal
121A anode connection surface or clamped portion of embedded portion of anode lead terminal
130. Cathode lead terminal
130A cathode lead terminal embedded part
130B exposed portion of cathode lead terminal
130C cathode lead terminal boundary
131A element mounting portion or clamped portion of embedded portion of cathode lead terminal
132A guide
1 st side area of buried part of 133A cathode lead terminal
Side surface region 2 of embedded part of 134A cathode lead terminal
1 st main surface area of embedded part of 135A cathode lead terminal
2 nd main surface area of buried part of 136A cathode lead terminal
137B side surface of exposed portion of cathode lead terminal
138B major surface of exposed portion of cathode lead terminal
140. Outer package
Claims (10)
1. A solid electrolytic capacitor, comprising:
at least 1 capacitor element including an anode portion and a cathode portion;
an anode lead terminal having an anode connection surface electrically connected to the anode portion;
a cathode lead terminal having a cathode connection surface electrically connected to the cathode portion; and
an exterior body covering the capacitor element,
The anode lead terminal and the cathode lead terminal have: having a main surface of the anode connection surface and a main surface of the cathode connection surface, and a side surface intersecting the main surface, and including an embedded portion embedded in the exterior body and an exposed portion exposed from the exterior body,
in at least one lead terminal selected from the anode lead terminal and the cathode lead terminal, at least a part of the main surface of the exposed portion is covered with a low melting point material, and,
at least a 1 st side surface region of the buried portion, which is greater than 0.36mm from a boundary between the buried portion and the exposed portion, is not covered with the low melting point material.
2. The solid electrolytic capacitor according to claim 1, wherein, of the main surface of the buried portion, at least a 1 st main surface region greater than 0.15mm from a boundary between the buried portion and the exposed portion is not covered with the low melting point material.
3. The solid electrolytic capacitor according to claim 1 or 2, wherein in the at least one lead terminal, further, the side face of the exposed portion is not covered with the low-melting-point material.
4. The solid electrolytic capacitor according to any one of claims 1 to 3, wherein the main surface of the at least one lead terminal is roughened.
5. The solid electrolytic capacitor according to claim 4, wherein the ratio of the developed interface area of the roughened main surface is 0.4 or more.
6. The solid electrolytic capacitor according to any one of claims 1 to 5, wherein the melting point of the low melting point material is 180 ℃ to 240 ℃.
7. The solid electrolytic capacitor according to claim 6, wherein the low melting point material is tin or solder.
8. The solid electrolytic capacitor according to any one of claims 1 to 7, wherein the embedded portion of the cathode lead terminal has a guide portion that stands up from the cathode connection surface to restrict a position of the capacitor element.
9. The solid electrolytic capacitor according to any one of claim 1 to 8, which has a plurality of the capacitor elements stacked,
in at least one of the anode lead terminal and the cathode lead terminal,
the embedded portion has a clamped portion interposed between 2 1 st and 2 nd elements adjacent to each other among the plurality of capacitor elements.
10. The solid electrolytic capacitor according to any one of claim 1 to 8, which has a plurality of the capacitor elements stacked,
The embedded portion of the cathode lead terminal has an element mounting portion adjacent to 1 of the capacitor elements disposed on the outermost side.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US202163160464P | 2021-03-12 | 2021-03-12 | |
| US63/160,464 | 2021-03-12 | ||
| JP2021-091791 | 2021-05-31 | ||
| PCT/JP2022/009126 WO2022191029A1 (en) | 2021-03-12 | 2022-03-03 | Solid electrolytic capacitor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116997983A true CN116997983A (en) | 2023-11-03 |
Family
ID=88521817
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202280019924.9A Pending CN116997983A (en) | 2021-03-12 | 2022-03-03 | Solid electrolytic capacitor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116997983A (en) |
-
2022
- 2022-03-03 CN CN202280019924.9A patent/CN116997983A/en active Pending
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