JPH0635464Y2 - Solid electrolytic capacitor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of the Invention The present invention relates to a solid electrolytic capacitor with a fuse to which a safety mechanism is added.

2. Description of the Related Art As a conventional solid electrolytic capacitor with a fuse, there is, for example, one disclosed in Japanese Patent Laid-Open No. 62-150817. Figure 2 is a view of the capacitor as seen from the front.
As shown in FIG. 2, the fuse material 6 is made of a low melting point alloy whose central portion excluding both ends is covered with an insulating coating 7 and bridges the gap between the capacitor element 1 and the external cathode terminal 3b. As described above, one of the fuse materials 6 is connected to the cathode layer of the capacitor element 1, and the other is connected to the external cathode terminal 3b. In FIG. 2, 2 is an insulating plate arranged on the end face of the capacitor element 1 on which the anode lead wire 4 is drawn out, 3a is an external anode terminal, 3b is an external cathode terminal, and 5 is a conductive adhesive or solder. And the like.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in the conventional device described above, there is a gap between the capacitor element 1 and the external cathode terminal 3b, and since the fuse material 6 has flexibility, the capacitor element is assembled at the time of assembly. 1. The external cathode terminal 3b is unstable, the capacitor element 1 is misaligned and exposed after the mold is packaged, the fuse material 6 is cut, the connection is defective due to peeling from the bonding material 5, and a short circuit, an increase in leakage current, and other characteristic defects. Was likely to occur.

The present invention solves such a problem, and an object of the present invention is to provide a solid electrolytic capacitor with a fuse having stable quality.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention has a method in which a semiconductor metal oxide layer and a cathode layer are sequentially laminated on an anode having an anode lead wire and having a dielectric oxide film on the surface. An insulating coating layer is formed on the surface of the cathode layer of the capacitor element except that a part of the fuse material is connected to the portion without the insulating coating layer, and the fuse material is connected to the insulating coating layer of the capacitor element. Is arranged so as to surround the outer surface in a U shape, and the other end is connected to an external cathode terminal.

Action With the above configuration, since the capacitor element is stably joined and fixed onto the external cathode terminal, it is possible to eliminate variations in characteristics and quality due to connection failure or the like.

Embodiment An embodiment of the present invention will be described below with reference to FIG.

FIG. 1 is a front view of a capacitor element portion of a fixed electrolytic capacitor with a fuse according to an embodiment of the present invention. In the figure, 11 is a capacitor element.
Forms a dielectric oxide film on a product obtained by molding tantalum powder and firing it in a vacuum, further forming a semiconductor metal oxide layer such as manganese dioxide on the surface, and then sequentially forming a carbon layer and a cathode layer. It is configured by stacking. Reference numeral 12 is an anode lead wire made of a tantalum wire led from the capacitor element 11. 13 is a water-repellent heat-resistant insulating plate such as Teflon. Reference numeral 14 is a conductive bonding material, which is composed of a conductive adhesive, solder, or the like. On the other hand, reference numeral 15 is an insulating coating layer, which is formed on the surface of the cathode layer of the capacitor element 11 by a means such as dipping, coating, or sheet sticking of an insulating resin except a part thereof. Reference numeral 16 denotes a fuse material, which is made of a plate-shaped or linear low-melting-point metal material. The fuse material 16 is bent in a U shape and surrounds the capacitor element 11 on the cathode layer side on the insulating coating layer 15 of the capacitor element 11. It is arranged as follows. Then, one end of the fuse material 16 bent to the upper surface side of the capacitor element 11 is bonded and fixed by a conductive bonding material 14 on the cathode layer without the insulating coating layer 15 on the capacitor element 11. The other end of the fuse material 16 bent to the lower surface side of the capacitor element 11 has an inner surface in contact with the insulating coating layer 15 of the capacitor element 11, and the outer cathode terminal 17 is electrically conductive to the outer surface of the other end of the fuse material 16. It is joined and fixed by the joining material 14. 18 is an external anode terminal.

According to the above-described embodiment, the fuse material 16 is conductively joined to the external cathode terminal 17, and the capacitor element 11 has the insulating coating layer thereon.
Since the structure is such that the capacitor element 11 and the external cathode terminal 17 are aligned with each other in a stable manner at the time of assembly, the structure of the fuse material 16 is eliminated. 50μm ~ 10μm thickness
Even when the fuse material 16 is thinned, deformation or stress such as pulling or kinking of the fuse material 16 can be prevented. Further, the positional deviation and inclination between the external cathode terminal 17 and the capacitor element 11 are eliminated, and the assembly and adjustment are easy, so that the workability is improved. Furthermore, it is possible to prevent the cutting of the fuse material 16, the peeling of the joint between the conductive bonding material 14 and the fuse material 16, and the defective exposure after the mold is packaged. Moreover, since the length of the U-shaped fuse material 16 is about twice or more the length of the conventional fuse material 6 shown in FIG. 2, it becomes larger than the conventional one when a short circuit failure occurs inside the element. An electric current flows, and the heat generated at that time blows the fuse material 16 more easily than before. This means that if the fuse material 16 is lengthened, the variation in the length between the ends of the fuse material 16 will decrease with respect to the unit length.
This is because the resistance value is increased and the fusing property of the fuse material 16 is improved. In particular, this effect is effective in a chip-shaped solid electrolytic capacitor with a small size fuse in which it is difficult to use a long fuse material.

As described above, according to the present invention, the assembling accuracy of the solid electrolytic capacitor with a fuse is improved, and the characteristic defects such as short circuit, leakage current increase and open, and the appearance defect such as exposure after the mold exterior is improved. It is possible to obtain a large effect, and to further reduce variations in the fusing characteristics of the capacitor, and to obtain stable and constant fusing characteristics.

[Brief description of drawings]

FIG. 1 is a sectional view of an element portion of a fixed electrolytic capacitor according to an embodiment of the present invention, and FIG. 2 is a sectional view of an element portion of a conventional fixed electrolytic capacitor. 11 …… Capacitor element, 12 …… Anode lead wire, 14 …… Conductive bonding material, 15 …… Insulation coating layer, 16 …… Fuse material, 17 ……
External cathode terminal.

Claims (1)

[Scope of utility model registration request] 1. A part of the surface of a cathode layer of a capacitor element, which is formed by sequentially stacking a semiconductor metal oxide layer and a cathode layer on an anode having an anode lead wire and having a dielectric oxide film on the surface. Except for this, an insulating coating layer is formed, one end of the fuse material is connected to the part without this insulating coating layer, and this fuse material is arranged so as to surround the outer surface of the insulating coating layer of the capacitor element in a U shape. A fixed electrolytic capacitor with the other end connected to the external cathode terminal.