JPH0244511Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a solid electrolytic capacitor, and in particular to a displacement suppressing mechanism for preventing undesired exposure of a capacitor element from an exterior resin material.

[Prior art] Generally, this type of solid electrolytic capacitor is
As shown in the figure, a metal wire having a valve action is attached in advance to a capacitor element A which is formed by press-molding metal powder having a valve action into a prismatic shape and sintering the anode lead B.
A plate-shaped first external lead member C is welded to this anode lead B, and a plate-shaped second external lead member C is welded to the anode lead B.
The external lead member D is connected to the electrode lead layer E as a cathode formed on the circumferential surface of the capacitor element A using a conductive adhesive F, and the entire circumferential surface of the capacitor element A is molded with a resin material G. It is constructed by covering.

By the way, the connection of the capacitor element A to the external lead member is made by welding the anode lead B to the first external lead member C, and then using the conductive adhesive interposed between the electrode lead layer E and the second external lead member D. This is done by heat-treating the agent F. In particular, when welding the anode lead B to the first external lead member C, if the capacitor element A is eccentric to the anode lead B, Or, if the anode lead B is deformed,
The capacitor element A moves in the direction of the arrow shown in FIG. 5 and is exposed from the resin material G.
For this reason, not only the appearance but also the moisture resistance is impaired.

[Problems to be solved by the invention] Therefore, as previously shown in Japanese Utility Model Application Publication No. 58-193628, the present applicant created a U-shaped bent portion at the inner end portion of the second external lead member. We have proposed a solid electrolytic capacitor in which the capacitor element is housed within the bent portion.

According to this capacitor, since the capacitor element is positioned by the bent portion of the second external lead member during assembly, even if a force in the direction of the arrow shown in FIG. Movement can be suppressed and exposure from the resin material can also be prevented.

However, although the first and second external lead members are formed by punching from a hoop material such as nickel silver, the width of the inner end portion of the second external lead member is particularly large. In connection with the miniaturization of the element, it is configured to be narrow, for example, about 1.2 to 1.5 mm. For this reason, there is a problem in that it is difficult to accurately form a U-shaped bent portion at the inner end portion.

Therefore, the purpose of the present invention is to provide a solid electrolytic capacitor that can reliably prevent horizontal displacement of the capacitor element with respect to the second external lead member with a simple configuration without impairing the workability of the external lead member. It's about doing.

[Means for solving the problem] Therefore, in order to achieve the above-mentioned purpose, the present proposal takes the following measures:
An electrode lead layer is formed on the circumferential surface of a capacitor element made of a metal powder having a valve action, and a metal wire having a valve action is drawn out as an anode lead from the metal powder, and a plate-shaped electrode layer is formed on the anode lead of the capacitor element. in which the first external lead member of the capacitor element is welded, a plate-shaped second external lead member is connected to the electrode extraction layer, and the entire circumferential surface of the capacitor element is covered with a resin material, wherein the second external lead member is welded.
A groove is formed in the side circumferential surface of the capacitor element opposite to the inner end of the outer lead member, and the inner end of the outer lead member is positioned within this groove.

[Function] According to this invention, since the inner end portion of the second external lead member is inserted into the groove formed on the side circumferential surface of the capacitor element during assembly, a force in the left and right direction is applied to the capacitor element. Even if it is, it is possible to prevent it from being misaligned with respect to the second external lead member, and also to avoid being exposed from the exterior resin material.

[Example] Next, an example of the present invention will be described with reference to FIGS. 1 to 3.

In the figure, reference numeral 1 denotes a capacitor element formed by press-molding metal powder having a valve action into a substantially prismatic shape (square) and sintering it;
Projections 2, 2 are integrally formed on both side portions, and a groove portion 3 is formed in the central portion.
A metal wire having a valve action is installed as an anode lead 4 in the capacitor element 1 prior to pressure molding of the metal powder, but it can also be welded to the circumferential surface of the anode lead 4. An electrode extension layer 5 serving as a cathode is formed on the circumferential surface of the capacitor element 1 via an oxide layer, a semiconductor layer, and a graphite layer.

On the other hand, anode lead 4 of capacitor element 1
A plate-shaped first external lead member 6 is welded to the electrode lead layer 5, and a plate-shaped second external lead member 7 is connected to the electrode lead layer 5 using a conductive adhesive 8. In particular, the inner end portion 7 of the second outer lead member 7
a is inserted into the groove 3 of the capacitor element 1. Note that the width of the groove portion 3 of the capacitor element 1 is equal to the width of the inner end portion 7a of the second external lead member 7.
The depth of the groove 3 is set to be larger than the thickness of the second external lead member 7, but the width and depth are set to be approximately 0.2 to 0.5 mm wider than the width of the second external lead member 7. It can be changed as appropriate depending on the relationship.
The entire circumferential surface of the capacitor element 1 is coated with a resin material 9 by molding.

[Effect of the invention] As described above, according to the present invention, since the inner end portion of the second external lead member is inserted into the groove of the capacitor element, a force in the left and right direction is not applied to the capacitor element during assembly. However, it is possible to prevent the capacitor element from being misaligned with respect to the second external lead member, and also to prevent the capacitor element from being exposed from the resin material. Therefore, the appearance and moisture resistance can be effectively improved.

Furthermore, by integrally forming a protrusion for forming a groove on the side peripheral surface of the capacitor element facing the inner end portion of the second external lead member, the surface area of the capacitor element is substantially increased. can be done. Therefore, the capacitance can be increased by about 3 to 8% even though the capacitor element is small.

[Brief explanation of the drawing]

Figure 1 is a side cross-sectional view showing one embodiment of the present invention;
The figure is a front sectional view of Fig. 1, Fig. 3 is a perspective view of a capacitor element, Fig. 4 is a side sectional view of a conventional example, and Fig. 5 is a capacitor when the anode lead is welded to the first external lead member. It is a top view which shows the movement of an element. In the figure, 1 is a capacitor element, 1a is a side surface, 3 is a groove, 4 is an anode lead, 5 is an electrode lead layer, 6 and 7 are first and second external lead members, 7a
9 is an inner end portion, and 9 is a resin material.

Claims (1)

[Claims for Utility Model Registration] (1) Forming an electrode lead layer on the circumferential surface of a capacitor element made of metal powder that has a valve action and from which a metal wire that has a valve action is led out as an anode lead. Then, a plate-shaped first external lead member is welded to the anode lead of this capacitor element, a plate-shaped second external lead member is connected to the electrode lead layer, and the entire circumferential surface of the capacitor element is covered with a resin material. A groove is formed on the side peripheral surface of the capacitor element opposite to the inner end portion of the second external lead member, and the inner end portion of the second external lead member is positioned within this groove. A solid electrolytic capacitor characterized by: (2) The solid electrolytic capacitor according to claim 1, wherein the width of the groove of the capacitor element is approximately 0.2 to 0.5 mm wider than the width of the inner end portion of the second external lead member. . (3) The solid electrolytic capacitor according to claim 1, wherein the capacitor element is formed into a substantially rectangular shape.