JP2007035861A - Solid electrolytic capacitor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small and thin solid electrolytic capacitor suitable, which is demanded as an apparatus becomes thin and small, and a power supply and its peripheral circuit are mounted in a very dense state. <P>SOLUTION: This chip-type solid electrolytic capacitor comprises a capacitor element having external terminals at both ends thereof, a lead for an anode led out therefrom, and a cathode layer formed on the peripheral surface thereof; and has the exterior resin coating as a whole. A high hardness insulator is provided at the root of the anode lead and a V-cut is provided in the anode lead, and the anode lead is bent at that portion as a starting point, and the portion of the anode lead more distal than the V-cut is connected to an external anode terminal plate on the capacitor element side. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a solid electrolytic capacitor. More specifically, the present invention relates to a terminal structure of a solid electrolytic capacitor.

With the progress of digitalization and higher frequency of electronic devices, solid electrolytic capacitors incorporated in power supply circuits of devices are required to have good high frequency characteristics. In addition, with the miniaturization and thinning of devices, the power supply and its peripheral circuits are also mounted with high density, and a small and thin solid electrolytic capacitor is required.
As a reduction in size and thickness, a chip-shaped structure, in particular, an external terminal provided on the side surface of the chip body has been proposed. As an example of this, as shown in FIG. 4, a pair of metal materials are arranged on both sides of the capacitor element as external terminals, the cathode layer side of the capacitor element and the external cathode terminal metal plate 7 are connected, and the external anode terminal metal plate 8 is provided with a slit, the anode lead 2 is passed through the slit portion 17, and the protruding portion is bent and welded (Japanese Patent Laid-Open No. 56-61120).
Further, as shown in FIG. 5, an anode terminal structure in which the tip of the anode lead 2 is bent and the bent portion is buried with a conductive layer 18 has been proposed (Japanese Patent Laid-Open No. 56-49511). .
JP-A-56-61120 JP 56-49511 A

When the anode lead is exposed to the outside of the external terminal, it is difficult to maintain the dimensional accuracy, such as having a deformed terminal structure with one protrusion on the other, so the speed when inserting into the carrier tape during product packaging There were problems such as difficult.
In addition, in the anode terminal structure in which the tip of the anode lead wire is bent and the bent portion is embedded with a conductive layer, the volume of the bent portion of the terminal tends to increase, and there is a problem that miniaturization is difficult. .

  A capacitor element in which a lead for the anode is drawn out and a cathode layer is formed on the peripheral surface, an external anode terminal metal plate connected to the anode lead, and an external cathode terminal metal plate connected to the cathode layer In the chip-type solid electrolytic capacitor externally coated with a resin, an insulator is provided at the base of the anode lead, and a V-cut portion is provided on the anode lead, bent at the starting point, and from the V-cut portion of the anode lead. A tip portion is connected to the external anode terminal plate on the capacitor element side, and a solid electrolytic capacitor is provided.

In the present invention, since the anode lead is V-cut and bent at an acute angle, the outer diameter dimension in the length direction can be shortened.
In addition, since the anode lead is V-cut and bent, the bending point is accurately positioned, and it is welded to the inside of the external anode terminal metal plate, and the external anode terminal has no protrusion, so the outer diameter dimension is It is stabilized.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view showing an example of the solid electrolytic capacitor of the present invention.
Reference numeral 1 denotes a capacitor element, in which one end of a lead 2 for anode made of a valve metal such as tantalum or niobium is embedded, and a binder is mixed with fine powder of the valve metal such as tantalum or niobium. Sponge-like anode sintered body formed by press-pressing powder and then sintering in vacuum, anodized film, manganese dioxide or conductive polymer layer, carbon layer on this sintered body And a cathode layer 3 made of a silver layer.
The cathode layer 3 is connected to the external cathode terminal metal plate 5 by a conductive adhesive 4 or the like.
Reference numeral 6 denotes an insulator, which is made of an organic polymer such as a polyester resin, an epoxy resin, a polyimide resin, a urethane resin, a silicon resin, or a fluorine resin, and is made of a highly insulating material. It has the objective of stabilizing the connection between the anode lead 2 and the anode sintered body at the root of the anode lead 2 protruding. It is preferable that the hardness of the insulator is high, but it is more preferable that the insulator can be modified with urethane or the like, for example, rather than a simple epoxy resin, and the impact can be alleviated to some extent. Further, it is preferable that the anode sintered body penetrates to some extent because the connection is further stabilized. Further, even if the liquid is cured, it may be a plate-shaped cured product from the beginning.
The anode lead 2 may be a round or square wire, or may be a plate. The lead 2 for the anode is provided with a V-cut portion 7 at the lead-out portion, and is bent at a substantially right angle from the starting point. The embedding place to be the anode sintered body may be the center, but the anode lead 2 is L-shaped, and is preferably shifted from the center. Further, it is preferable to perform the V-cut while pressing at least the protruding root of the anode lead 2 with a pressing jig or the like. Further, the V-cut may be performed at one place or a plurality of places including two or more places.
The external anode terminal metal plate 8 is connected by providing a connecting portion 9 at the end of the anode lead 2 bent by cold press or friction stir welding using a rotary tool in addition to resistance and laser welding. Is done.
The material of the external anode or cathode terminal metal plate is 42 alloy, copper, or silver. A plating layer may be provided on the surface.
Reference numeral 10 denotes a sealing filling resin, which is made of a thermosetting resin such as a phenol resin, an epoxy resin, an unsaturated polyester resin, or a polyimide resin.

FIG. 2 is an explanatory diagram for explaining an example of the manufacturing method of the present invention.
First, as shown in FIG. 2 (a), a plurality of capacitor elements 1 are manufactured by being fixed to a mounting bar 11, an insulator 6 at the base of the anode lead 2, and a conductive adhesive on the opposite side. 4 are provided.
Next, as shown in FIG. 2B, the left pedestal 12 is provided with the external cathode terminal metal plate 5 and the spacer 13, and the external cathode terminal metal plate 5 and the conductive adhesive 4 are connected to each other. Each capacitor element 1 is placed on the side.
The spacer 13 is not limited to a bulk material, but may be a sponge shape, a stitch shape, a hollow shape, a corrugated plate shape, or the like, but it is preferable that the physical properties of the sealing filler resin 10 are close to each other.
Further, an external anode terminal metal plate 7 is provided on the right rotating pedestal 14, and while holding the anode lead 2 with the holding jig 15 from the outside of the insulator 6 of the anode lead 2, the V cut portion 7 and the connecting portion are provided. After 9 is provided, it is rotated approximately 90 degrees around the V-cut portion 7 in the opposite direction to the clock in the figure.
Next, as shown in FIG. 2 (c), the right rotating pedestal is removed, and the left pedestal 16 is provided so as to be combined with the left pedestal 12 instead. This united seat has a container shape with an open top.
Next, as shown in FIG. 2D, the sealing filling resin 10 is poured into the united seat and cured.
Next, as shown in FIG. 2E, the united seat is removed, the surface is polished, and then cut into each capacitor.

  First, after processing the capacitor element as shown in FIGS. 2A and 2B, the capacitor element 1 is sandwiched between the lower mold 19 and the upper mold 20 as shown in FIG. 3 instead of FIG. The sealing filling resin is poured from the mold cavity 21, filled, and then cured. Next, after removing the mold lower mold 19 and the mold upper mold 20, each of the capacitors is cut.

It is sectional drawing which shows an example of the solid electrolytic capacitor of this invention. It is explanatory drawing for demonstrating an example of the manufacturing method of this invention. Example 1 It is explanatory drawing for demonstrating the mold process of another example of the manufacturing method of this invention. (Example 2) It is the perspective view and sectional drawing which show a prior art example. It is sectional drawing which shows another prior art example.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Capacitor element, 2 ... Lead for anode, 3 ... Cathode layer, 4 ... Conductive adhesive, 5 ... External cathode terminal metal plate, 6 ... Insulator, 7 ... V cut part, 8 ... External anode terminal metal plate, DESCRIPTION OF SYMBOLS 9 ... Connection part, 10 ... Sealing filling resin, 11 ... Mounting bar, 12 ... Left base, 13 ... Spacer, 14 ... Right rotation base, 15 ... Holding jig, 16 ... Left base, 17 ... Slit part, 18 ... Conductive layer, 19 ... lower mold, 20 ... upper mold, 21 ... mold cavity.

Claims (1)

  A capacitor element in which a lead for the anode is drawn out and a cathode layer is formed on the peripheral surface, an external anode terminal metal plate connected to the anode lead, and an external cathode terminal metal plate connected to the cathode layer In a chip-type solid electrolytic capacitor externally coated with a resin, an insulator is provided at the base of the anode lead, and a V-cut portion is provided on the anode lead, bent at the starting point, and from the V-cut portion of the anode lead. A solid electrolytic capacitor characterized in that a tip portion is connected to the external anode terminal plate on the capacitor element side.

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