JP2010287912A - Solid electrolytic capacitor and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve low ESL (Equivalent Series Inductance) of a solid electrolytic capacitor. <P>SOLUTION: The solid electrolytic capacitor is configured by bonding an anode part and a cathode part of a capacitor element 1 to the upper surfaces of an anode terminal 10 and a cathode terminal 11 respectively and coating the capacitor element with insulating exterior resin 12. In the solid electrolytic capacitor, the anode terminal 10 and the cathode terminal 11 are configured like plates, the lower surfaces of the terminals to be mounting surfaces are arranged on the same reference plane, the lower surfaces of the terminals except respective center portions form thin portions 10a, 11a respectively by thinning the thicknesses of both ends of lower surfaces in a direction orthogonal to a direction connecting the anode terminal 10 and the cathode terminal 11, the side faces of the center portion and the thinned portions 10a of the anode terminal 10, the side faces being opposed to the cathode terminal 11, are formed flush with each other, and the side faces of the center portion and the thinned portions 11a of the cathode terminal 11, the side faces being opposed to the anode terminal 10, are formed flush with each other, so that a drawing distance from the capacitor element 1 up to the terminal is shortened. Consequently excellent ESR (Equivalent Series Resistance) characteristics and the low ESL are achieved. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a solid electrolytic capacitor using a conductive polymer used in various electronic devices as a solid electrolyte.

  Along with the higher frequency of electronic equipment, capacitors that are one of the electronic components have been required to have better impedance characteristics in the high frequency range than before. Various solid electrolytic capacitors using a polymer as a solid electrolyte have been studied.

  4 is a sectional view showing the structure of this type of conventional solid electrolytic capacitor, FIG. 5 is a perspective view thereof, and FIG. 6 is a partially cutaway perspective view showing the structure of a capacitor element used in the solid electrolytic capacitor. 4 to 6, reference numeral 20 denotes a capacitor element. The capacitor element 20 is formed by forming a dielectric oxide film layer on the surface of an anode body 21 made of an aluminum foil which is a valve metal, and then insulating resist portions. 22 is separated into an anode part 23 and a cathode part 24, and a solid electrolyte layer 25 and a cathode layer 26 made of carbon and silver paste are sequentially laminated on the surface of the cathode part 24.

  27 is an anode comb terminal, 28 is a cathode comb terminal, 28a is a guide part formed by bending a part of the connecting surface of the cathode comb terminal 28, and the anode part 23 of the capacitor element 20 is connected to the anode comb terminal. Similarly, the cathode portion 24 is mounted on the connection surface of the cathode comb terminal 28 on the connection surface 27, and the anode portion 23 of the capacitor element 20 is joined by resistance welding by bending the connection portion 27a of the connection surface of the anode comb terminal 27. The cathode portion 24 is connected to the connection surface of the cathode comb terminal 28 via a conductive silver paste (not shown).

Reference numeral 29 denotes an insulating exterior resin that covers the capacitor element 20 in a state where a part of the anode comb terminal 27 and the cathode comb terminal 28 to which the capacitor element 20 is bonded is exposed on the outer surface. The anode comb terminal 27 and the cathode comb terminal 28 exposed from 29 are each bent from the side surface to the bottom surface along the exterior resin 29 to form external terminals, thereby forming a surface mount type solid electrolytic capacitor. It is.

  As prior art document information related to the invention of this application, for example, Patent Document 1 is known.

JP 2000-340463 A

  However, in the above-described conventional solid electrolytic capacitor, the shapes of the anode comb terminal 27 and the cathode comb terminal 28 connected to the anode part 23 and the cathode part 24 of the capacitor element 20 are not only complicated and costly. In addition, there is a problem that the ESL (equivalent series inductance) characteristic is poor because the distance from the connection surface (the anode portion 23 and the cathode portion 24) between the anode comb terminal 27 and the cathode comb terminal 28 to the capacitor element 20 to the mounting surface is long. In recent years, it has been strongly desired to reduce the size and capacity of electrolytic capacitors used around the CPU of personal computers, etc. In addition to lowering ESR (equivalent series resistance) in response to high frequencies, it is also possible to eliminate noise. In addition, it has a problem that it cannot be adopted in a situation where it has excellent transient response and low ESL.

  An object of the present invention is to solve such a conventional problem and to provide a solid electrolytic capacitor capable of achieving low ESL by shortening a drawing distance from a capacitor element to a terminal. .

  In order to solve the above-described problems, the present invention provides a laminate of a plurality of capacitor elements each having an anode part and a cathode part, and an anode lead frame having the anode part placed on the upper surface, and the anode lead frame joined together. An anode terminal for taking out the anode part of the capacitor element on the lower stage, a cathode lead frame on which the cathode part of the capacitor element on the lowermost stage is placed on the upper surface, and joined to the cathode lead frame, In a solid electrolytic capacitor comprising a cathode terminal for external extraction and an insulating exterior resin integrally covering the capacitor element in a state where the anode terminal and the lower surface serving as a mounting surface of the cathode terminal are exposed, the anode terminal and The cathode terminal is configured in a flat plate shape, and the lower surface serving as the mounting surface is disposed on the same reference surface, and the lower surfaces of the anode terminal and the cathode terminal are The cathode terminals of the central portion and the thin portion of the anode terminal are formed by reducing the thickness of both ends in the direction perpendicular to the direction connecting the anode terminal and the cathode terminal, except for the central portion. The side surface opposite to the anode terminal is formed flush with the cathode terminal, and the side surface facing the anode terminal of the central portion and the thin portion of the cathode terminal is formed flush.

  As described above, according to the present invention, the anode part and the cathode part of the capacitor element using the conductive polymer for the solid electrolyte are joined to the upper surfaces of the anode terminal and the cathode terminal, In the solid electrolytic capacitor in which the capacitor element is integrally covered with an insulating exterior resin with the lower surface exposed, the anode terminal and the cathode terminal are configured in a flat plate shape, and the lower surface serving as the mounting surface is on the same reference surface. The lower surfaces of the anode terminal and the cathode terminal are thinned by reducing the thickness at both ends in the direction orthogonal to the direction connecting the anode terminal and the cathode terminal, except for the central portion. The side surface of the anode terminal at the side facing the cathode terminal is formed flush with the center portion of the anode terminal and the side of the thin wall portion facing the anode terminal. The side of the is formed flush The configurations, it is possible to shorten the lead-out distance from the capacitor element to the terminal, excellent ESR characteristics, and is intended to achieve the particular effect to be understood that both the ESL.

(A) Plan sectional drawing which showed composition of a solid electrolytic capacitor by one embodiment of the present invention, (b) Front sectional view, (c) Bottom sectional view, (d) Side sectional view Partially cutaway perspective view showing a capacitor element used in the solid electrolytic capacitor (A) The top view which showed the base material which provided the anode terminal and the cathode terminal, (b) Sectional drawing in an AA line Sectional view showing the structure of a conventional solid electrolytic capacitor Same perspective view Partially cutaway perspective view showing a capacitor element used in the solid electrolytic capacitor

Example 1
Hereinafter, the invention described in all claims of the present invention will be described using embodiments.

  1A to 1D are a plan sectional view, a front sectional view, a bottom sectional view, and a side sectional view showing a configuration of a solid electrolytic capacitor according to an embodiment of the present invention, and FIG. It is the partially cutaway perspective view which showed the structure of the capacitor | condenser element used for a capacitor | condenser.

  1 and 2, reference numeral 1 denotes a capacitor element. The capacitor element 1 has an insulating resist portion after a dielectric oxide film layer (not shown) is formed on the surface of an anode body 2 made of an aluminum foil which is a valve metal. 3 is separated into an anode part 4 and a cathode part 5, and a solid electrolyte layer 6 and a cathode layer 7 made of carbon and silver paste are sequentially laminated on the surface of the cathode part 5. .

  Reference numeral 8 denotes an anode lead frame. The anode part 4 is placed in a state where a plurality of the capacitor elements 1 (5 sheets in the present embodiment) are stacked on the anode lead frame 8, and the guide parts 8a at both ends are placed. The anode part 4 is wrapped and bent, and laser welding is performed at the joining part 8b to join together.

  Reference numeral 9 denotes a cathode lead frame. A plurality of the capacitor elements 1 are stacked on the cathode lead frame 9 and the cathode portion 5 is placed through a conductive adhesive (not shown). In this way, a plurality of capacitor elements 1 are laminated and integrated by the anode lead frame 8 and the cathode lead frame 9 as described below. This is called an element unit.

  Reference numeral 10 denotes an anode terminal, and the anode terminal 10 is formed in a reverse convex shape having a thin wall portion 10a by reducing the thickness at both ends. On the anode terminal 10, the anode lead frame 8 of the capacitor element unit is formed. Are joined by performing laser welding at the joining portions 10b in the thin-walled portions 10a at both ends.

  Reference numeral 11 denotes a cathode terminal. The cathode terminal 11 is formed in a reverse convex shape having a thin wall portion 11a with a thin wall at both ends. On the cathode terminal 11, the cathode lead frame 9 of the capacitor element unit is formed. Are joined by performing laser welding at the joint portions 11b in the thin-walled portions 11a at both ends.

Reference numeral 12 denotes an insulating exterior resin in which the capacitor element unit is integrally covered with the lower surfaces serving as the mounting surfaces of the anode terminal 10 and the cathode terminal 11 being exposed. In this embodiment, an epoxy resin is used. It is.

  3A and 3B are a plan view showing the anode terminal 10 and the cathode terminal 11 and a cross-sectional view taken along the line AA, in which 13 is a hoop-like base material made of a copper alloy. , 13a are feed holes for intermittently conveying the base material 13; Reference numerals 10 and 11 denote an anode terminal and a cathode terminal, and a plurality of the terminals are continuously provided on the hoop-like base material 13 at a predetermined interval. A capacitor element unit is mounted on the anode terminal 10 and the cathode terminal 11. Are joined together with the exterior resin 12 and then separated from the base material 13 into individual pieces.

  In addition, the anode terminal 10 and the cathode terminal 11, which are integrally formed on the base material 13 in this way, are configured by etching a single plate-like base material 13. In addition to removing unnecessary portions, the thickness of both ends excluding the central portion of the anode terminal 10 and the cathode terminal 11 is reduced to form thin portions 10a and 11a at the same time. The thin portions 10a and 11a and the central portion The step is secured to 80 μm or more.

  Note that the step between the thin portion and the central portion is based on dimensions necessary for the exterior resin 12 covering the capacitor element unit to sufficiently flow into and cover the step portion.

  The solid electrolytic capacitor according to the present embodiment configured as described above is drawn out by taking out the anode part 4 and the cathode part 5 of the capacitor element 1 from the flat anode terminal 10 and the cathode terminal 11. Since the distance can be shortened, the ESR characteristic is excellent and the low ESL can be realized. In particular, with respect to the ESL characteristic, the solid electrolytic capacitor according to the present embodiment is As a result, the pH was as low as 800 pH, which was almost halved compared with 1500 pH of the conventional product.

  Further, the thickness of both ends excluding the central portion of the anode terminal 10 and the cathode terminal 11 is reduced to provide thin portions 10a and 11a, and the anode lead frame 8 and the cathode of the capacitor element unit are provided in the thin portions 10a and 11a. By adopting a structure in which the lead frames 9 are joined by laser welding, the welding marks resulting from the joining are covered with the exterior resin 12, so that the appearance is not only beautiful, but the welding marks cause floating during mounting. This eliminates the possibility of causing mounting defects and can greatly contribute to the improvement of reliability.

  In the present embodiment, a plurality of capacitor elements 1 are stacked and joined to the anode lead frame 8 and the cathode lead frame 9 to form a capacitor element unit. The capacitor element unit is connected to the anode terminal 10 and the cathode. Although an example in which a solid electrolytic capacitor is configured by bonding to each of the terminals 11 has been described, the present invention is not limited to this, and one sheet without using the anode lead frame 8 and the cathode lead frame 9. Alternatively, a plurality of capacitor elements 1 can be directly laminated and joined to the anode terminal 10 and the cathode terminal 11, respectively, and this makes it possible to further reduce the ESL. The number of stacked capacitor elements 1 may be appropriately determined according to the purpose.

  Further, in the present embodiment, the anode body 2 constituting the capacitor element 1 has been described by taking an example of a configuration made of an aluminum foil, but the present invention is not limited to this, and the tantalum or niobium foil, A sintered body or a combination of these materials may be used.

  Moreover, although the base material 13 which comprises the anode terminal 10 and the cathode terminal 11 was demonstrated with the hoop-shaped thing which consists of a copper alloy, a material and a shape are not limited to this similarly.

  Moreover, although the thin part 10a and 11a provided in the anode terminal 10 and the cathode terminal 11 demonstrated by the method formed by an etching, this is not limited to this similarly, Even if it forms a thin part by press molding good.

  In the solid electrolytic capacitor according to the present invention, the anode terminal and the cathode terminal are formed in a flat plate shape, so that the lead-out distance from the capacitor element to the terminal can be shortened. In particular, it is useful as a capacitor used around a CPU of a personal computer.

DESCRIPTION OF SYMBOLS 1 Capacitor element 2 Anode body 3 Resist part 4 Anode part 5 Cathode part 6 Solid electrolyte layer 7 Cathode layer 8 Anode lead frame 8a, 9a, 9b Guide part 8b, 10b, 11b Joint part 9 Cathode lead frame 10 Anode terminal 10a, 11a Thin part 11 Cathode terminal 12 Exterior resin 13 Base material 13a Feed hole

Claims (3)

A plurality of capacitor elements having an anode part and a cathode part are laminated,
An anode lead frame on which the anode part of the capacitor element at the bottom is placed on the upper surface;
An anode terminal joined to the anode lead frame and taking out the anode part from the outside;
A cathode lead frame on which the cathode portion of the capacitor element at the bottom is placed on the upper surface;
A cathode terminal joined to the cathode lead frame and taking out the cathode part from the outside;
In a solid electrolytic capacitor made of an insulating exterior resin that integrally covers the capacitor element in a state in which a lower surface serving as a mounting surface of the anode terminal and the cathode terminal is exposed,
The anode terminal and the cathode terminal are configured in a flat plate shape, and the lower surface serving as the mounting surface is disposed on the same reference surface, and the lower surfaces of the anode terminal and the cathode terminal are each except for the central portion, Reducing the thickness of both ends in the direction perpendicular to the direction connecting the anode terminal and the cathode terminal to form a thin portion;
The side surfaces of the central portion and the thin portion of the anode terminal facing the cathode terminal are formed flush with each other,
A solid electrolytic capacitor in which a central part and a thin part of the cathode terminal are flush with each other on the side facing the anode terminal. The solid electrolytic capacitor according to claim 1, wherein the cathode lead frame is provided with three guide portions for positioning three side surfaces of the cathode portions of the plurality of capacitor elements. A plurality of capacitor elements having an anode part and a cathode part are laminated,
An anode lead frame on which the anode part of the capacitor element at the bottom is placed on the upper surface;
An anode terminal joined to the anode lead frame and taking out the anode part from the outside;
A cathode lead frame on which the cathode portion of the capacitor element at the bottom is placed on the upper surface;
A cathode terminal joined to the cathode lead frame and taking out the cathode part from the outside;
It consists of an insulating exterior resin that integrally covers the capacitor element in a state in which the lower surface to be the mounting surface of the anode terminal and the cathode terminal is exposed,
The anode terminal and the cathode terminal are configured in a flat plate shape, and the lower surface serving as the mounting surface is disposed on the same reference surface, and the lower surfaces of the anode terminal and the cathode terminal are each except for the central portion, Reducing the thickness of both ends in the direction perpendicular to the direction connecting the anode terminal and the cathode terminal to form a thin portion;
The side surfaces of the central portion and the thin portion of the anode terminal facing the cathode terminal are formed flush with each other,
The method for producing a solid electrolytic capacitor in which the central portion and the thin portion of the cathode terminal have a side surface facing the anode terminal formed on the same plane,
As the anode terminal and the cathode terminal, a plate-like base material in which an anode terminal and a cathode terminal are integrally provided at a predetermined interval is used, and the anode lead frame is respectively formed on the anode terminal and the cathode terminal of the base material. Mounting and joining the cathode lead frame,
A method for producing a solid electrolytic capacitor, comprising: coating the capacitor element joined to the anode lead frame and the cathode lead frame with the exterior resin, and then dividing the capacitor element from the base material to obtain individual pieces.

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