JPH01241813A - Solid electrolytic capacitor having open mechanism - Google Patents

Abstract

PURPOSE:To prevent refusion and open reliability, by connecting a fuse wire and a conductive metal spring in series and at the time when a part of a fuse wire is melt and cut by the pulling of fuse wires by using a conductive metal spring connected in series and widening the gap at the melted section of the fuse wire. CONSTITUTION:An anode lead 2 led out in a planted manner from a capacitor element 1 such as tantalum, niobium, aluminum is connected to an anode terminal 4 by welding. Next, a conductive metal spring 8 is connected in series to a fuse wire 7 by welding. An insulating resin case 9 such as epoxy having internal space to which the other ends of the fuse wire 7 and the conductive metal spring 8 are led out, is prepared. One end of the fuse wire 7 is connected to a cathode layer 3 which is a positive electrode of the capacitor element 1 with solder 6. One end of the conductive metal spring 8 is connected to a cathode lead terminal 5 by welding. In due course of time, outer covering with resin is carried out by transfermolding and resin potting with a part of the anode lead terminal 4 and the cathode lead 5 left. Lastly, the anode lead terminal 4 and the cathode lead 5 are molded to a U shape for a product.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a solid electrolytic capacitor with an open mechanism,
This particularly concerns the structure of the opening mechanism.

[Conventional technology]

Conventionally, solid electrolytic capacitors made of metals with valve action, such as tantalum (Ta), niobium (Nb), and aluminum, have been used in various electronic circuits, and their advantage is that they have a low failure rate. However, when a failure occurs, the failure mode is often a short-circuit failure, and a large short-circuit current flows, causing the capacitor element to generate heat, which may eventually lead to burnout.

When a failure occurs due to such an excessive short-circuit current, it is necessary to change the failure mode from a short-circuit to an open circuit in order to protect other circuit components. Fuses are generally used as a countermeasure against this problem, and the conventional technology is
There are 19029 etc.

A solid electrolytic capacitor with an open mechanism according to Utility Model Application Publication No. 59-119029 has a structure in which a cathode lead terminal 5 and a capacitor element 1 are connected with an insulating adhesive 11, as shown in FIG.
Thereafter, the fuse wire 7 was connected between the cathode lead terminal 5 and the capacitor element 1, and finally the structure was covered with resin.

[The problem that the invention attempts to solve]

The conventional solid electrolytic capacitor with an open mechanism described above has a structure in which when the capacitor fails and a short circuit current flows, the fuse wire 7 generates heat, and a part of it in particular becomes red hot and melts and blows out. Since the fuse wire 7 is covered with the exterior resin 10, the melted fuse wire 7 remains as it is, and the electrical connection is maintained, so that the fuse wire 7 is not opened and may burn out.

In addition, since the fuse wire 7 is covered with the exterior resin 10, the heat generated by the fuse wire 7 is radiated to the exterior resin 10, preventing the temperature rise of the fuse wire 7 and preventing the fuse wire 7 from blowing out. Therefore, it had the disadvantage of poor fusing characteristics.

SUMMARY OF THE INVENTION An object of the present invention is to provide a solid electrolytic capacitor with an open mechanism that has stable fuse blowing characteristics and prevents the problems of conventional Z fuses, such as variations in blowing characteristics or burnout without blowing.

[Means for Solving the Problem] The solid electrolytic capacitor with an open mechanism of the present invention is a solid electrolytic capacitor with an open mechanism, which is a fume-like solid electrolytic capacitor formed by connecting a cathode lead terminal to a capacitor element via an anode lead terminal and a fuse wire. A conductive metal spring is connected in series with the fuse leg, the fuse wire and the conductive metal spring are housed in a hollow resin case to form an open mechanism, and the open mechanism is connected between the capacitor element and the cathode lead terminal. It is constructed as a percentage sign that ζ is connected.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a perspective view showing the internal structure of an embodiment of a solid electrolytic capacitor with an open mechanism according to the present invention.

FIGS. 2 and 3 are longitudinal sectional views showing the structure of the opening mechanism section.

First, as shown in Figure 1, tantalum and niobium.

An anode lead 2 taken out in a raised shape from a capacitor element 1 made of aluminum or the like is connected to an anode lead terminal 4 by welding. Next, a conductive metal spring 8 is connected in series with the fuse wire 7 shown in FIG. 2 by welding, and the other ends of the fuse wire 7 and the conductive metal spring 8 are taken out. An insulating resin case 9 is prepared. One end of this fuse wire 7 is connected to the cathode layer 3, which is the negative electrode of the capacitor element 1, by solder 6. Further, one end of the conductive metal spring 8 is connected to the cathode lead terminal 5 by welding. Thereafter, resin packaging is performed by transfer molding, resin botting, etc., leaving a portion of the anode lead terminal 4 and cathode lead terminal 5.

Finally, the anode lead terminal 4 and the cathode lead terminal 5 are formed into a U-shape to form a product.

Here, the resin case 9 has a conductive metal spring 8 inserted therein.
The fuse wire 7 and the conductive metal spring 8 have a size that allows the fuse wire 7 and the conductive metal spring 8 to be expanded and contracted, and have a hole through which the fuse wire 7 and one end of the conductive metal spring 8 can be taken out, and the exterior resin 10 does not enter inside the resin case, that is, the fuse wire 7 and the conductive metal spring 8 It is desirable to make the hole just large enough that it can barely move.

FIG. 2 shows a case where a helical conductive metal spring 8 is used, and FIG. 3 shows a case where a box-shaped conductive metal spring 8 is used. Weld to this conductive metal lead terminal.

FIG. 4(a) is a sectional view showing the internal structure of a second embodiment of the self-supporting solid electrolytic capacitor with an open mechanism according to the present invention.

In the case of the second embodiment, an anode lead terminal 4 is connected to an anode lead 2 erected from a capacitor element 1 by welding. Next, the portion of the fuse wire 7 protruding from the resin case 9 is connected to the upper surface of the capacitor element with the solder 6. Furthermore, the portion of the conductive metal spring 8 protruding from the resin case 9 is connected to the cathode lead terminal 5 by welding. Thereafter, the anode lead terminal 4 and the cathode lead terminal 5 are partially covered with resin by transfer molding, resin potting, etc.

FIG. 4(b) is a sectional view of a third embodiment of the present invention,
A case is shown in which a resin case 9 containing a fuse wire 7 and a conductive metal spring 8 is attached to the side surface of the capacitor element 1.

61 [Effects of the Invention] As explained above, the present invention provides a solid electrolytic capacitor with an open mechanism in which a conductive metal spring is connected in series with a fuse wire, thereby preventing a short circuit in the capacitor element due to failure of the capacitor element. When current flows, the fuse wire generates heat and a part of the fuse wire melts, causing it to blow out.
The series-connected conductive full-wire springs pull the fuse wire, widening the gap between the fused portions of the fuse wire, preventing re-fusion, and ensuring a secure opening.

This has the effect of preventing problems that occur in conventional solid electrolytic capacitors with built-in fuses, such as the fuse not blowing or the fuse blowing characteristics varying.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the internal structure of a solid electrolytic capacitor with an open mechanism according to the first embodiment of the present invention, FIG.
The figure is a vertical sectional view showing the structure of the opening mechanism part, and Figure 4 (
a) and FIG. 4(b) are vertical cross-sectional views showing the internal structures of second and third embodiments of the present invention, and FIG. 5 is a vertical cross-sectional view of a conventional solid electrolytic capacitor with an open mechanism. 1... Capacitor element, 2... Anode lead, 3... Cathode layer, 4... Anode lead terminal, 5-... Cathode lead terminal, 6... Solder, 7... Fuse wire, 8... Conductive metal spring, 9... Resin case, 10...
...Exterior resin, 11...Insulating adhesive. Agent Patent Attorney Susumu Uchihara

Claims (1)

[Claims] In a solid electrolytic capacitor with an open mechanism in which a cathode lead terminal is connected to a capacitor element via an anode lead terminal and a fuse wire, a conductive metal spring is connected in series with the fuse wire, and the fuse wire and the conductive metal spring are connected to each other in series with the fuse wire. What is claimed is: 1. A solid electrolytic capacitor with an open mechanism, characterized in that the open mechanism is constructed by housing the capacitor in a hollow resin case, and the open mechanism is connected between a capacitor element and a cathode lead terminal.