JPH0227560Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a solid electrolytic capacitor, and particularly relates to a connection structure with an external lead that prevents exposure of a capacitor element from a 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 made by press-forming metal powder having a valve action into a prismatic shape and sintering it, and an 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 formed on the circumferential surface of the capacitor element A via an oxide layer and a semiconductor layer using a conductive adhesive F, and the entire circumferential surface of the capacitor element A is covered with resin. It is constructed by mold-covering with material G.

By the way, the anode lead B of the capacitor element A is welded to the first external lead member C, and the electrode lead layer E is welded to the second external lead member D by heat curing of a conductive adhesive F such as silver paste. However, if, for example, capacitor element A is eccentric with respect to anode lead B, or if anode lead B is deformed, welding of anode lead B to first external lead member C may occur. At this time, the capacitor element A separates from the second external lead member D in the direction of the arrow shown in FIG. In addition to damaging the connection, a portion of the capacitor element A is exposed from the resin material G. For this reason, not only the appearance but also the electrical connectivity and moisture resistance are impaired.

[Problem that the invention attempts to solve]

Therefore, as previously shown in the specification of Utility Model Application No. 58-6369, the present applicant formed an L-shaped cut-and-raised piece facing the inner end portion on the second external lead member, and We have proposed a solid electrolytic capacitor in which a capacitor element is placed between the raised piece and the inner end.

According to this proposal, since the end of the capacitor element is held between the inner end portion of the second external lead member and the cut and raised piece, the capacitor element may be eccentric, or the anode lead may be eccentric. Even if deformation occurs, the capacitor element will not separate from the second external lead member when the anode lead is welded to the first external lead member, and the electrode lead layer and second external lead member will not separate. Not only can the capacitor element be electrically connected reliably, but also the capacitor element can be prevented from being exposed from the resin material.

However, the external dimensions of the capacitor (L x W x
If H) is configured to be small, for example, 4.57 x 2.54 x 1.78 mm, the width of the first and second external lead members will naturally be narrower, so the L-shaped notches are formed by press working. This poses a problem in that not only is it difficult to form the strips, but also the molding accuracy is reduced, making it difficult to achieve the intended purpose.

Therefore, an object of the present invention is to provide a solid electrolytic capacitor that can reliably prevent exposure of a capacitor element from a resin material, regardless of the external dimensions of the capacitor element, by using a simple structure.

[Means to solve the problem]

Therefore, in order to achieve the above-mentioned purpose, the present proposal:
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 led out from the metal powder as an anode lead, and a first electrode lead layer is formed on the anode lead of the capacitor element. A second external lead member is welded to the electrode lead layer, and a second external lead member is connected to the electrode lead layer via a conductive adhesive, and the entire circumferential surface of the capacitor element is molded and covered with a resin material. forming an inclined part at the end of the element and a bent part corresponding to the inclined part at the inner end of the second external lead member;
The inclined portion is engaged with the bent portion.

[Effect]

According to this invention, the inclined portion of the capacitor element is engaged with the bent portion of the second external lead member, so that when the anode lead is welded to the first external lead member, the capacitor element is attached to the anode lead. Even if the anode lead is eccentric, or the anode lead is deformed, separation of the capacitor element from the second external lead member can be reliably prevented.

〔Example〕

Next, an embodiment of the present invention will be described with reference to FIG.

In the figure, reference numeral 1 denotes a capacitor element made by press-forming metal powder with a valve action into a prismatic shape and sintering it, and in the center of the element is a metal wire having a valve action before the metal powder is press-formed. is planted as the anode lead 2. Incidentally, an inclined portion 1a is integrally formed at the end of the anode lead 2 of the capacitor element 1 on the non-lead side. An electrode extension layer 3 is formed on the circumferential surface of the capacitor element 1 via an oxide layer and a semiconductor layer. On the other hand, a plate-shaped first external lead member 4 is welded to the anode lead 2 of the capacitor element 1, and a plate-shaped second external lead member 5 is welded to the electrode lead layer 3 using conductive material such as silver paste. They are connected via adhesive 6. A Z-shaped bent portion 7 is formed at the inner end portion of the second external lead member 5, and the inclined portion 1 of the capacitor element 1 is formed with a Z-shaped bent portion 7.
a is engaged with this bent portion 7. The entire circumferential surface of the capacitor element 1 is molded and covered with a resin material 8.

[Effect of idea]

As described above, according to the present invention, since the inclined part of the end of the capacitor element is engaged with the bent part of the second external lead member, when welding the anode lead and the first external lead member, the capacitor element Even if a force that causes the second external lead member to separate from the second external lead member is applied, it is possible to prevent the second external lead member from separating from the second external lead member. Therefore, exposure of the capacitor element from the resin material can be prevented, and not only the appearance but also the moisture resistance can be improved.

Furthermore, the bent portion is formed at the inner end portion of the second external lead member, and since the bent portion is formed over the entire width direction, it can be easily processed regardless of its size. be able to.

[Brief explanation of drawings]

Figure 1 is a side cross-sectional view showing one embodiment of the present invention;
The figure is a side sectional view of a conventional example, and FIG. 3 is a side sectional view for explaining a method of welding the anode lead to the first external lead member. In the figure, 1 is a capacitor element, 1a is an inclined part, 2 is an anode lead, 3 is an electrode lead layer, 4 is a first external lead member, 5 is a second external lead member, 6 is a conductive adhesive, and 7 8 is a bent portion, and 8 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 first external lead member is welded to the anode lead of this capacitor element, a second external lead member is connected to the electrode lead layer via a conductive adhesive, and the entire circumferential surface of the capacitor element is covered with resin. In the capacitor element, an inclined portion is formed at the end of the capacitor element, and a bent portion corresponding to the inclined portion is formed at the inner end portion of the second external lead member, and the inclined portion is formed into a bent portion. A solid electrolytic capacitor characterized by being engaged with a solid electrolytic capacitor. (2) The solid electrolytic capacitor according to claim 1, wherein the first and second external lead members are formed by punching from a plate material.