JPH0572091B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a solid electrolytic capacitor made of tantalum or aluminum, and more specifically, to a dip-type solid electrolytic capacitor equipped with a fuse.

[Conventional technology]

FIG. 3 shows a typical conventional example of a dip type solid electrolytic capacitor. That is, this solid electrolytic capacitor A is made of a sintered powder metal such as tantalum, and has a capacitor element 1 on the surface of which a semiconductor layer such as manganese dioxide and a cathode layer such as carbon or conductive silver paste are formed. , the anode lead wire 2 is connected to the anode lead 1a, and the cathode surface 1b of the capacitor element 1 is connected to the anode lead wire 2.
Connect the cathode lead wire 3 to. Then, the capacitor element 1 is immersed in a predetermined electrically insulating synthetic resin liquid, and a resin exterior body 4 is formed around it.

This type of solid electrolytic capacitor uses a metal sintered body for the anode, so it is small and is superior to liquid capacitors in terms of no leakage, but it has durability against surge voltages and reverse voltages. Therefore, in the event of a short-circuit failure, a large short-circuit current will flow, potentially causing an overheating accident.

Therefore, conventionally, when connecting the cathode lead wire 3 to the cathode surface 1b of the capacitor element 1, a fuse wire is interposed between them (see, for example, Japanese Utility Model Publication No. 54-21730).

[Problem to be solved by the invention]

According to this, the fuse wire is blown out in the event of an overcurrent, so that a heat generation accident can be prevented, but there are the following problems in production.

That is, the necessity of a fuse is determined by the use of the capacitor, but after production, it is not possible to change a capacitor with a fuse to one without a fuse, or vice versa.

Therefore, conventionally, both are manufactured separately, but it is not desirable from the viewpoint of inventory management to manufacture and stock the high-cost fuse-equipped ones in particular.

[Means to solve the problem]

In order to solve the above problems, in the present invention, an anode lead wire is connected to the anode lead of a capacitor element made of a sintered body of valve metal such as tantalum, and a cathode lead wire is connected to the cathode surface of the capacitor element. In a dip-type solid electrolytic capacitor in which a capacitor element is immersed in a predetermined electrically insulating synthetic resin liquid and a resin outer shell is formed around it, the electrically insulating resin is placed outside the resin outer shell, leaving both ends intact. A second cathode lead wire with a coating formed thereon is disposed, and a fuse wire is connected between one end of the second cathode lead wire and the cathode lead wire, and the method includes the second cathode lead wire and the fuse wire. It is characterized in that a second resin exterior body is formed around the resin exterior body.

Furthermore, the above problem was solved by arranging a second anode lead wire with an electrically insulating resin coating formed on both ends, and connecting the second anode lead wire and the above anode lead wire to the outside of the resin exterior body. This problem can also be solved by connecting a fuse wire therebetween and forming a second resin sheath around the resin sheath including the second anode lead wire and the fuse wire.

[Effect]

For example, a fuse wire can be connected to the cathode lead wire of a dip-type solid electrolytic capacitor without a fuse.
A dip-type solid electrolytic capacitor with a fuse is obtained by connecting the cathode lead wire and immersing it in a resin solution. In addition, since the second cathode lead wire is coated with an electrically insulating resin coating,
Even if the fuse wire and the second cathode lead wire come into contact during the dip, the resistance value of the fuse wire will not change.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 1 and 2.

This solid electrolytic capacitor B is a fuse-equipped version of the fuseless dip-type solid electrolytic capacitor A described above with reference to FIG.

That is, the cathode lead wire 3 of the capacitor A is preferably cut short, a new cathode lead wire (second cathode lead wire) 5 is prepared, and the cathode lead wire 5 is placed outside the resin exterior body 4. . An electrically insulating resin coating 8 is formed on this cathode lead wire 5 except for both ends thereof.

After connecting a fuse wire 6 between the cathode lead wire 3 and one end of this new cathode lead wire 5, the cathode lead wire 5 and the fuse wire 6 are immersed in a resin solution for forming an exterior body (not shown). A new resin exterior body (second exterior body) 7 is formed around the resin exterior body 4 including the resin exterior body 4.

In this case, since the electrically insulating resin coating 8 is formed on the cathode lead wire 5, even if the cathode lead wire 5 and the fuse wire 6 come into contact when forming the resin sheath 7, the fuse length will be short. That's not going to happen. Note that the cathode lead wire 3 of the capacitor A is not cut short, but is bent downward (to the side opposite to the protruding side of the anode lead wire 2) in FIG. You can also wire.

In this embodiment, the electrically insulating resin coating 8 is formed on the cathode lead wire 5 as follows. First, as shown in FIG. 2a, one end of the cathode lead wire 5 is supported by a suitable hoop material 9, and a resin adhesion prevention agent 10 is applied to the other end. Examples of the resin adhesion inhibitor 10 include Surflon (trade name) manufactured by Asahi Glass Co., Ltd. and Daifree (trade name) manufactured by Daikin Industries, Ltd., for example.
The coating may be done by dipping into a liquid or by brushing. Next, the cathode lead wire 5 is immersed in an epoxy resin solution (not shown) to form an electrically insulating resin coating 8 on the cathode lead wire 5, as shown in FIG. 2b. Note that the electrically insulating resin coating 8 may be formed by, for example, brushing or spraying. After that, the resin adhesion prevention agent 10 is removed using, for example, a fluorocarbon-based solvent, and
Expose the other end of the cathode lead wire 5 (Fig. 2c)
reference). However, if the resin adhesion prevention agent 10 is gone after the electrically insulating resin coating 8 is cured, there is no need to perform this removal step.

In the above embodiment, the second cathode lead wire 5 is placed along the cathode lead wire 3 side, and the fuse wire 6 is inserted between them.
However, in this invention, the anode lead wire 2
It also includes placing a second anode lead on the side and routing a fuse wire therebetween. However, even in that case, the electrically insulating resin coating is formed on the second anode lead wire except for both ends thereof.

〔Effect of the invention〕

As described above, according to the present invention, a highly reliable dip-type solid electrolytic capacitor with a fuse can be easily obtained from a dip-type solid electrolytic capacitor without a fuse as required.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of a dip-type solid electrolytic capacitor according to the present invention, and FIG.
3c is an explanatory view showing the step of forming an electrically insulating resin coating on the cathode lead wire shown in FIG. 1, and FIG. 3 is a sectional view showing a conventional example. In the figure, 1 is a capacitor element, 2 is an anode lead wire, 3 is a cathode lead wire, 4 is an exterior body, 5 is a second cathode lead wire, 6 is a fuse wire, 7 is a second exterior body, and 8 is an electrical Insulating resin coating, 9 hoop material, 1
0 is a resin adhesion inhibitor.

Claims (1)

[Claims] 1. An anode lead wire is connected to the anode lead of a capacitor element made of a sintered body of a valve metal such as tantalum, and a cathode lead wire is connected to the cathode surface of the capacitor element, and the capacitor element is In a dip-type solid electrolytic capacitor formed by immersing it in a predetermined electrically insulating synthetic resin liquid and forming a resin sheath around it, the electrically insulating resin coating is placed on the outside of the resin sheath except for both ends. disposing the formed second cathode lead wire, and connecting a fuse wire between one end of the second cathode lead wire and the cathode lead wire, including the second cathode lead wire and the fuse wire; A solid electrolytic capacitor characterized in that a second resin exterior body is formed around the resin exterior body. 2 Connect the anode lead wire to the anode lead of a capacitor element made of a sintered body of valve metal such as tantalum, and connect the cathode lead wire to the cathode surface of the capacitor element, and then combine the capacitor element with a specified electrically insulating composition. In a dip-type solid electrolytic capacitor that is immersed in a resin liquid and has a resin sheath formed around it, a second electrically insulating resin coating is formed on the outside of the resin sheath except for both ends. An anode lead wire is arranged, a fuse wire is connected between one end of the second anode lead wire and the anode lead wire, and the area around the resin sheath including the second anode lead wire and the fuse wire is A solid electrolytic capacitor characterized in that a second resin exterior body is formed on the solid electrolytic capacitor.