JP2842067B2 - Chip solid electrolytic capacitor with fuse - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chip solid electrolytic capacitor with a fuse.

[0002]

2. Description of the Related Art In general, solid electrolytic capacitors are used in various electronic circuits, and it is considered that a small failure rate is an advantage. However, once a failure occurs, a short circuit often occurs. If a large short-circuit current flows in such a case, the capacitor element may generate heat and burn out. In addition to preventing the capacitor element from burning out at the time of failure due to this excessive short-circuit current,
In order to protect the peripheral circuit components, it is necessary to release the capacitor from the short circuit. Conventionally, a solid electrolytic capacitor having a built-in fuse is used for this purpose. Such a solid electrolytic capacitor is called a solid electrolytic capacitor with a fuse. FIG. 4 is a partially sectional perspective view showing the structure of a conventional chip solid electrolytic capacitor with a fuse, and FIG. 5 is a sectional view thereof.

As shown in the figure, a capacitor element 1 comprises an anode lead 2 and a cathode layer 3, and an anode terminal 4 is connected to the anode lead 2. The fuse 7 is connected to the internal connection part 5 a and the external lead part 5 b of the cathode terminal 5, and is covered with a protective resin 11 to protect the fuse 7. The cathode layer 3 is bonded to the internal connection portion 5a of the cathode terminal 5 having a built-in fuse with a solder 12. These are insulated by an exterior resin 10.

[0004]

The above-mentioned conventional chip solid electrolytic capacitor with a fuse has the following disadvantages since the fuse 7 is completely covered with the protective resin 11.

That is, since the periphery of the fuse is firmly covered with the resin, when a short-circuit current flows through the fuse, the fuse is solidified by the resin even if the fuse is melted. , The electrical connection is maintained, and the fuse is not blown.

An object of the present invention is to provide a chip solid electrolytic capacitor with a fuse which can reliably blow a fuse when a capacitor is short-circuited and prevent burning of a capacitor element.

[0007]

According to the present invention, there is provided a solid electrolytic capacitor element having an anode terminal connected to an anode lead wire derived from the solid electrolytic capacitor element and a fuse connected to a cathode layer of the solid electrolytic capacitor element. A cathode terminal,
An exterior resin that covers the entire body except for a predetermined portion of the anode terminal and the cathode terminal; and the cathode terminal includes an internal connection portion to which a fuse is connected and an external lead portion, and includes an internal connection portion and an external lead portion. It is characterized in that a concave portion is provided in a resin for protecting and covering the fuse connection region.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of an embodiment of the present invention.
FIG. 2 is a partially sectional perspective view showing the internal structure of one embodiment of the present invention. FIG. 3 is a plan view of a structure in which a fuse is connected to the cathode terminal and then covered with a protective resin.

The anode lead 2 is press-molded in a state in which a part of the anode lead 2 is buried in a metal powder having a valve action, such as tantalum or aluminum, and the anode body is vacuum-sintered and then anodized.
A manganese dioxide, a carbon layer, a plating layer, and a solder layer are sequentially formed on the anodic oxide film by a known means to obtain a solid electrolytic capacitor element 1.

Next, the internal connection portion 5a and the external lead-out portion 5b
And a predetermined portion (at least a connection portion of the internal connection portion with the cathode layer, a fuse connection portion, and a fuse connection portion of a part of the extraction portion of the external extraction portion) are exposed and have a concave portion. Insulation coating is performed with the protective resin 11. Thereafter, the fuse 7 is connected between the internal connection portion 5a exposed in the concave portion and the external lead portion 5b.

Next, the anode lead 2 led out of the solid electrolytic capacitor element 1 is resistance-welded to the anode terminal, and the cathode layer 3 formed on the outer periphery of the solid electrolytic capacitor element 1 is welded.
Is connected to the internal connection portion 5a of the cathode terminal 5 by the solder 12.

Next, the assembled product is exposed and insulated with an exterior resin 10 by a transfer molding method by exposing predetermined portions of the anode terminal 4 and the cathode terminal 5, and a chip solid electrolytic device with a fuse according to one embodiment of the present invention is provided. Get a capacitor.

[0014]

As described above, according to the present invention, the protective resin for the cathode terminal with a fuse is provided with a concave portion, and the fuse is provided in the concave portion. Since the fuse is not hardened, the fuse is quickly blown and the circuit can be opened.

[Brief description of the drawings]

FIG. 1 is a sectional view of a solid electrolytic capacitor with a fuse according to an embodiment of the present invention.

FIG. 2 is a perspective view including a partial cross section of a solid electrolytic capacitor with a fuse according to one embodiment of the present invention.

FIG. 3 is a plan view of a cathode terminal before assembly according to an embodiment of the present invention.

FIG. 4 is a partial sectional perspective view of an example of a conventional chip solid electrolytic capacitor with a fuse.

FIG. 5 is a sectional view of the conventional example shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Capacitor element 2 Anode lead 3 Cathode layer 4 Anode terminal 5 Cathode terminal 5a Internal connection part 5b External lead-out part 7 Fuse 10 Exterior resin 11 Protective resin 12 Solder

Claims (1)

(57) [Claims] An anode terminal connected to an anode lead wire derived from the solid electrolytic capacitor element; a cathode terminal with a fuse connected to a cathode layer of the solid electrolytic capacitor element; In a flip solid electrolytic capacitor with a fuse, the cathode terminal includes an internal connection portion to which a fuse is connected and an external lead portion, and has a resin that protects and covers a part of the internal connection portion and the external lead portion to which the fuse is connected. A chip solid electrolytic capacitor with a fuse, wherein a concave portion is provided in a resin for protecting and covering the internal connection portion and the external lead portion.