JP2008187114A - Chip-type solid electrolytic capacitor and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem wherein when a side surface of a cathode layer of a capacitor element is connected to a cathode side-surface terminal plate using a conductive adhesive, the conductive adhesive spreads wider than the width of a cathode terminal to seep out from coating of a coating resin because of the variations in the quantity of the conductive adhesive or variation of pressing force to the cathode terminal, in a chip-type solid electrolytic capacitor of a side electrode, which is insulated by the coating resin and is provided with an external connection terminal on a side surface side thereof. <P>SOLUTION: To provide a chip-type solid electrolytic capacitor, wherein a dam-like resin material is provided to the periphery of four sides of the inner surface of the cathode side-surface terminal plate. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a chip-type solid electrolytic capacitor and a method for manufacturing the same. In particular, the present invention relates to a chip-type solid electrolytic capacitor having a side electrode provided with external connection terminals on both sides and a method for manufacturing the same.

The side electrode chip type solid electrolytic capacitor has an anode terminal and a cathode terminal on the side surface of the capacitor. The capacitor element in which one end of the anode lead is embedded is formed on the outermost cathode layer opposite to the anode lead. In addition to being connected to the cathode terminal via a conductive adhesive, it was connected to the anode terminal in a direction perpendicular to the lead-out direction of the anode lead, and the capacitor element was covered with an exterior made of an insulating resin or the like (Patent Document) 1).
JP 2000-348975 A

The problem to be solved is that the conductive adhesive spreads beyond the width of the cathode terminal due to variations in the amount of the conductive adhesive or the pressing force on the cathode terminal, and protrudes from the coating of the exterior resin. This is the point where this occurs. This variation is particularly likely to occur when a large number of side electrode capacitors are manufactured simultaneously. The protrusion of the conductive adhesive from the coating of the exterior resin has a negative effect on the terminal strength and corrosion resistance of the cathode terminal.

The present invention includes an anode sintered body formed by embedding one end of a valve action metal anode lead, press-pressing a powder obtained by mixing a binder into a fine powder of a valve action metal, and sintering the powder. A capacitor element in which an anodized film, a solid electrolyte layer, and a cathode layer are sequentially provided on the sintered body, an anode side terminal connected to the anode lead directly or via a lead metal, and a side surface of the cathode layer A cathode side terminal plate connected by a conductive adhesive, and a solid electrolytic capacitor that wraps the capacitor element and has an exterior resin that separates the anode side terminal and the cathode side terminal plate. Another object is to provide a chip-type solid electrolytic capacitor characterized in that a dam-like resin material is provided around the inner surface of the plate.
Further, the present invention provides a step of providing a lattice-shaped resin material on the surface of the metal plate and disposing the metal plate on the bottom surface side of the container with the upper surface open, and an anode lead for valve action metal above the metal plate. An anode sintered body formed by embedding one end, press-pressing and sintering a powder obtained by mixing a binder with a fine powder of a valve action metal, an anodized film, and a solid electrolyte layer And a plurality of capacitor elements sequentially provided with a cathode layer, with the anode lead side facing upward, in accordance with the position of the grid, and in the grid of the grid-like resin material or the anode lead A conductive adhesive provided on the surface of the cathode layer opposite to the side, a step of connecting and solidifying the metal plate and the cathode layer, and insulation for the exterior in the container so that the cathode layer is buried The step of filling the resin and the anode lead side in the middle A method for manufacturing a chip-type solid electrolytic capacitor, comprising: a step of providing an anode side surface terminal electrically connected to the anode lead side while cutting; and a step of cutting adjacent regions of the capacitor element on the metal plate. Is to provide.

The chip-type solid electrolytic capacitor of the present invention can prevent the conductive adhesive from protruding from the coating of the exterior resin by providing a dam-shaped resin material around the inner surface of the cathode side surface terminal plate. .
In addition, since individual separation can be performed after assembly, it is not necessary to separately attach external terminals, and the manufacturing cost can be reduced correspondingly.

The anode lead described in the present invention is made of a valve action metal such as linear or strip-shaped tantalum or niobium, and is led out from one end face of the anode sintered body.
As the conductive adhesive described in the present invention, a general adhesive can be used. For example, a conductive binder such as gold, silver, copper, nickel or carbon is dispersed in a binder made of an organic substance. It is obtained.
The cathode side surface terminal plate described in the present invention is made of copper, iron, zinc, nickel, or an alloy thereof, and those obtained by plating them with nickel, zinc, tin or the like. Examples of alloys include brass and 42 alloy, and examples of plating include tin and tinplate. Any metal can be selected which is rich in workability such as ductility and has good plating properties such as solder and tin, and good connectivity with the conductive paste.
The dam-shaped resin material described in the present invention is for preventing the conductive adhesive from spreading outward, and can be appropriately selected from a sealing material, an exterior material, and the like. As the resin, the same resin material as that of the exterior resin of the present invention is preferable, and a resin that increases the filling rate of the inorganic powder and the like and suppresses the fluidity than the exterior resin is preferable.

Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic cross-sectional view of a chip-type solid electrolytic capacitor according to the present invention.

  Reference numeral 1 denotes a capacitor element, in which one end of an anode lead 2 made of a valve action metal wire or strip thin plate is embedded, and a powder obtained by mixing a binder with a fine powder of the valve action metal is press-press molded, Sponge-like anode sintered body formed by sintering in vacuum, anodized film on this sintered body, solid electrolyte layer such as manganese dioxide and conductive polymer, cathode layer of carbon layer or silver layer Are sequentially provided. The solid electrolyte is provided on the surface of the anodic oxide film, and manganese dioxide or a conductive polymer can be used as the material. As the conductive polymer, in addition to polythiophene obtained by chemical oxidative polymerization of a thiophene monomer, for example, polypyrrole or polyaniline can be used. The forming method is not limited to chemical oxidative polymerization, and can be formed by electrolytic oxidative polymerization.

  Reference numeral 3 denotes a cathode side surface terminal plate made of copper, iron, zinc, nickel, or an alloy thereof having a thickness of about 50 μm to 500 μm, and those plated with nickel, zinc, tin or the like. Examples of alloys include brass and 42 alloy, and examples of plating include tin and tinplate. Any metal can be selected which has excellent workability such as ductility and good plating properties such as solder and tin. The conductive adhesive 4 is electrically connected to the end face of the capacitor element opposite to the anode lead 2 side. The inner surface of the cathode side surface terminal plate may be a flat surface. However, it is preferable that the inner surface of the cathode side surface terminal plate has unevenness of about several tens of μm because mechanical connection with the capacitor element end surface is improved.

Reference numeral 5 denotes a dam-shaped resin material which is provided so as to surround the inner side end four sides of the cathode side surface terminal plate 3 and has a height of about 10 μm to 500 μm. The conductive adhesive 4 protrudes from the cathode side surface terminal plate 3. It is provided so that it does not. The resin of the dam-like resin material is preferably a material of the same system as the exterior resin. In particular, a higher viscosity before solidification than the exterior resin is preferable because a high height can be obtained with a smaller area. For this reason, it is preferable to add a larger amount of filler to the resin material or to use a polymer having a higher molecular weight.
Further, when the shape expands from the top toward the center of the cathode side surface terminal plate 3, it becomes a guide, and the capacitor element end surface side opposite to the anode lead 2 side is the cathode side surface terminal plate 3 (metal plate 11). ), When approaching the cathode side terminal plate 3 (metal plate 11), it tends to be closer to the center of the cathode side terminal plate 3, which is preferable in this respect.

  A lead metal 6 is electrically connected to the anode lead 2 by welding or the like. It consists of copper, iron, zinc, nickel, or alloys thereof made of a plate or wire, and those plated with nickel, zinc, tin or the like. Examples of alloys include brass and 42 alloy, and examples of plating include tin and tinplate. Any metal can be selected which has excellent workability such as ductility and good plating properties such as solder and tin. In FIG. 1, the lead metal 6 is an example of a plate material, but a through hole 7 may be provided in a connection portion with the anode lead 2 so that the tip of the anode lead 2 can be easily cut. The lead metal 6 is not necessarily required, but for this purpose, it is necessary to make the surface of the anode lead 2 easy to plate, such as removal of an oxide film by plasma treatment or thermal spraying of a metal that can be easily plated.

  8 is an exterior resin, and a general sealing material such as an epoxy resin is used. In particular, a resin having a low viscosity is preferable from the viewpoint of easy resin filling.

  Reference numeral 9 denotes an anode side surface terminal made of a metal having a thickness of about 50 μm to 500 μm. Although it may be a metal plate, it is formed by electrolytic plating. In that case, the electroless plating layer 10 is provided on the base.

FIG. 2 shows a metal plate used for manufacturing a chip-type solid electrolytic capacitor according to the present invention.
Reference numeral 11 denotes a metal plate that becomes the cathode side surface terminal plate 3 after cutting.
Reference numeral 12 denotes a lattice-shaped resin material that becomes a dam-shaped resin material 5 after cutting.

FIG. 3 shows an example of a method for manufacturing a chip-type solid electrolytic capacitor according to the present invention.
FIG. 3 (a) shows a step of providing a lattice-shaped resin material on the surface of the metal plate, disposing the metal plate on the bottom surface side of the open container, and providing a conductive adhesive in the lattice therebetween, And a step of hanging a plurality of capacitor elements in accordance with the position of the lattice with the anode lead side facing upward.
FIG. 3B shows a process in which the conductive adhesive and the cathode layer are connected and solidified, and the container is filled with an insulating resin so that the cathode layer is buried.
FIG. 3C shows a step of providing an anode side surface terminal while cutting the anode lead or the lead metal in the middle.
FIG. 3D shows a step of cutting adjacent regions of the capacitor element on the metal plate.

First, as shown in FIG. 3A, the lattice-shaped resin material 12 is printed on the surface of the metal plate 11 by screen printing or the like and solidified.
Next, the metal plate 11 is disposed on the inner bottom surface side of the container 13 with the top surface open. The container 13 is easier to use if it can be divided into a bottom part and a side part. Moreover, it becomes easy to prevent the outer resin from flowing out by pressing the peripheral portion of the metal plate 11 through the packing 14 to the bottom of the side surface of the container 13. The material of the container 13 is not particularly limited, but when a silicone resin-based molded body is used for the side surface portion, the packing 14 can be omitted and the peelability from the exterior resin is good.
Next, the conductive adhesive 4 is provided by potting in each lattice of the lattice-shaped resin material 12. The metal plate 11 may be provided by screen printing or the like before being put in the container 13.
Capacitor element 1 has an anode sintered body formed by embedding one end of a valve action metal anode lead, press-pressing a powder mixed with a binder into a fine powder of valve action metal, and sintering. A general capacitor element in which an anodized film, a solid electrolyte layer, and a cathode layer such as a carbon layer or a silver layer are sequentially provided, and a lead metal 6 formed into a comb shape in accordance with the position of the lattice of the lattice-like resin material 12 The tip end side of the anode lead 2 is welded to the tip end side of the comb, arranged in a row with a gap, and suspended. A plurality of rows are provided depending on production efficiency. When the lead metal 6 is not used, the tip side of the anode lead of the capacitor element 1 is welded to a plate-shaped stainless steel plate, arranged in a line with a gap, and suspended.

  Next, as shown in FIG. 3B, the capacitor element 1 is lowered, the conductive adhesive 4 and the cathode layer 15 of the capacitor element 1 are connected, and after solidification, the cathode layer 15 is buried. The container is filled with an insulating resin to be the exterior resin 8. Next, after the surface of the insulating resin is surface-treated, an electroless plating layer 10 of, for example, copper having a thickness of about 5 to 50 μm is provided as a base. For example, a copper electroless plating layer 10 may be provided after cutting the lead metal 6 (the anode lead 2 when the lead metal 6 is not used). Further, the conductive adhesive 4 may be provided on the surface of the cathode layer opposite to the anode lead side.

  Next, as shown in FIG. 3C, after cutting the lead metal 6 (the anode lead 1 when the lead metal 6 is not used), for example, a copper electrolytic plating layer having a thickness of about 50 μm to 500 μm. 9 is provided. In addition, a plating layer of nickel, zinc, tin, or the like is appropriately provided on the upper layer. The above electroless plating or electrolytic plating may be performed after removing the side plate of the container.

Next, as shown in FIG. 3D, a double-sided adhesive 16 of a type whose adhesiveness is weakened by heating is provided between the inner bottom surface of the container 13 and the metal plate 11, and the capacitor element on the metal plate 11. The adjacent region of 1 is cut with a diamond cutter or the like. After heating, the individual capacitors are removed. Although the double-sided adhesive 16 is provided between the container 13 and the metal plate 11 in the figure, a flat plate may be used instead of the container 13. Moreover, in FIG. 3, although it cut | disconnected from the plating layer surface, you may turn over and cut | disconnect from the direction of the metal plate 11. FIG.

1 shows a schematic view of a chip-type solid electrolytic capacitor according to the present invention. 1 shows a metal plate according to the present invention. 1 illustrates a method for manufacturing a chip-type solid electrolytic capacitor according to the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Capacitor element, 2 ... Anode lead | read | reed, 3 ... Cathode side terminal board, 4 ... Conductive adhesive agent, 5 ... Dam-shaped resin material, 6 ... Lead-out metal, 7 ... Through-hole, 8 ... Exterior resin, 9 ... Anode side terminal, 10 ... electroless plating layer, 11 ... metal plate, 12 ... lattice-shaped resin material, 13 ... container, 14 ... packing, 15 ... cathode layer, 16 ... double-sided adhesive.

Claims (2)

  An anode sintered body formed by embedding one end of a valve action metal anode lead, press-pressing and sintering a powder obtained by mixing a binder with a fine powder of the valve action metal, and sintering the sintered body. Capacitor element in which an anodized film, a solid electrolyte layer, and a cathode layer are sequentially provided, an anode side terminal connected to the anode lead directly or through a lead metal, and conductive adhesion to the side of the cathode layer A solid electrolytic capacitor having a cathode side surface terminal plate connected by an agent and an exterior resin that encloses the capacitor element and separates the anode side surface terminal and the cathode side surface terminal plate, A chip-type solid electrolytic capacitor characterized in that a dam-shaped resin material is provided around. A step of providing a lattice-shaped resin material on the surface of the metal plate and disposing the metal plate on the bottom surface side of the open top container;
An anode sintered body formed by embedding one end of a valve action metal anode lead above the metal plate, press-pressing and sintering a powder obtained by mixing a binder with a fine powder of the valve action metal. And a step of suspending a plurality of capacitor elements sequentially provided with an anodized film, a solid electrolyte layer, and a cathode layer on the sintered body in accordance with the position of the lattice with the anode lead side facing upward,
A step of connecting and solidifying the metal plate and the cathode layer with a conductive adhesive provided in the lattice of the lattice-shaped resin material or on the surface of the cathode layer opposite to the anode lead side;
Filling the container with an exterior insulating resin so that the cathode layer is buried;
Providing an anode side surface terminal electrically connected to the anode lead side while cutting the anode lead side in the middle;
And a step of cutting adjacent regions of the capacitor element on the metal plate.

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