JPH0731537Y2 - Solid electrolytic capacitor with fuse - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a solid electrolytic capacitor with a fuse, and more particularly to a solid electrolytic capacitor with a fuse having a reverse mounting prevention structure.

[Prior Art] Generally, solid electrolytic capacitors are used in various electronic circuits and have a low failure rate.However, if a large short-circuit current flows in the event of a failure, the capacitor element may generate heat and burn out. is there.

In addition, since the solid electrolytic capacitor has polarity, when the capacitor is mounted in the opposite direction and a reverse voltage is applied, the capacitor element may generate heat and may be burnt out. As a conventional technique for preventing the reverse mounting and the burnout prevention, the external terminals are symmetrically arranged as shown in FIG. 3, and the external terminals having the symmetrical relationship are mounted in either direction with the same polarity. There is a solid electrolytic capacitor with a fuse, which has a four-terminal structure that does not occur and which has a fuse wire provided across the outer surface of the capacitor element.

[Problems to be solved by the device]

The above-mentioned conventional solid electrolytic capacitor with a fuse is the third
As shown in the figure, the anode lead 2 derived from the capacitor element 1 and the U-shaped anode external terminal 3 are connected by welding or the like, and the first side surface of the capacitor element 1 is formed on the surface of the cathode layer 4 of the capacitor element 1. An insulating layer 5 is provided on the left and right portions and the portions of the second and third side faces 1C and 1D except for the central portion of 1b, and two cathode external terminals 6 are arranged symmetrically on both sides of the capacitor element 1. The cathode layer 4 is connected to the cathode layer 4 with the solder 8 or the like by the fuse wire 7, and then the exterior resin 9 is provided by a method such as transfer molding.

Therefore, the conventional solid electrolytic capacitor with a fuse is
As shown in FIGS. (A) and (b), the first capacitor element 1
Since the fuse wire 7 is provided along the side surface 1b of the fuse wire 7, in order to cover the fuse wire 7 with the exterior resin 9 as shown in FIG. The dimension becomes thick. Furthermore, since it is a component that can be mounted in either direction, it must be symmetric not only in the width direction of the component but also in the thickness direction.
The exterior resin 9 that covers the fourth side surface 1E where the fuse wire is not provided must also be thick. Therefore, the thickness of the fuse wire 7 is at least twice as large as the diameter of the fuse wire 7 as compared with a solid electrolytic capacitor without a fuse, and the external dimensions of the component are large.

An object of the present invention is to provide a solid electrolytic capacitor with a fuse which is significantly smaller than a conventional solid electrolytic capacitor with a fuse.

[Means for Solving the Problems]

The solid electrolytic capacitor with a fuse of the present invention is a solid electrolytic capacitor having a plurality of cathode external terminals and terminals having a symmetrical relationship with respect to the center of the extraction surface of the anode external terminal having the same polarity. The cathode layer on the side opposite to the anode lead extraction surface is covered with an insulating material, leaving the central part, and the cathode layer and a plurality of external terminals of the cathode are connected by a fuse across the insulating material to form an insulating sheath. It is characterized by having done.

〔Example〕

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

1 (a) to (c) are a front view, a right side view and a top view of an embodiment of the present invention, respectively. In the figure, 1 is a solid electrolytic capacitor element, 1a is the opposite surface of the anode lead extraction surface, 1a
b, 1c, 1D, 1E are the first and the first of the solid electrolytic capacitor elements, respectively.
2, 3rd and 4th side surfaces, 2 is an anode lead drawn from the capacitor element 1, 3 is an anode external terminal, 4 is a cathode layer, 5 is an insulating layer, 6 is a cathode external terminal, 8 is solder, 9 is an exterior It is a resin.

First, a metal powder having a valve action, such as tantalum or aluminum, is pressure-molded into a desired shape and size and then sintered in a vacuum to form a porous anode body. Then, a dielectric layer is formed on the surface of the metal powder forming the anode body by anodic oxidation, and then a semiconductor layer such as manganese dioxide, a graphite layer and a silver base layer are sequentially formed on the surface of the dielectric layer to form an outermost package. Then, a solid electrolytic capacitor element (hereinafter abbreviated as element) 1 having a cathode layer 4 is formed. Furthermore, the first
As shown in FIG. 1C, an insulating layer 5 is provided by an insulating resin except for the central portion on the surface 1a of the cathode layer 4 provided on the outer peripheral surface of the element 1 opposite to the extraction surface of the cathode lead 2, and FIG. As described above, the insulating layer 5 is provided on the entire surfaces of the second and third side faces 1c and 1D of the element 1.

Next, the anode lead 2 drawn out from the element 1 and the U-shaped anode external terminal are connected by welding, and the fuse wire 7
The cathode external terminal 6 is further connected to the fuse wire 7 and the cathode layer 4 on the surface 1a opposite to the lead-out surface of the anode lead by using solder 8, conductive adhesive or the like. After that, the exterior resin 9 is coated by a method such as transfer molding to form a solid electrolytic capacitor with a fuse.

2 (a) to 2 (c) are a front view, a right side view and a top view of another embodiment of the present invention, respectively.

The second embodiment is a three-terminal solid electrolytic capacitor with a fuse using a hook-shaped external anode terminal 13. In this embodiment, since there is one anode external terminal, it is possible to save the material compared to the first embodiment, there is an advantage of low cost, and it is obvious that the same effect as the first embodiment is obtained.

[Effect of device]

As described above, according to the present invention, the fuse wire is attached to the surface opposite to the lead-out surface of the anode lead and connected to the cathode layer and the cathode external terminal. It is of great industrial value.

[Brief description of drawings]

1 (a) to (c) are front views, right side views and top views of an embodiment of the present invention, and FIGS. 2 (a) to (c) are front views of other embodiments of the present invention, A right side view and a top view, and FIGS. 3A to 3C are a front view, a right side view and a top view of an example of a conventional solid electrolytic capacitor with a fuse. 1 ... Solid electrolytic capacitor element, 1a ... Surface opposite to anode lead extraction surface, 1b, 1c, 1D, 1E ... 1st, 2nd, 3rd, 4th side surface of solid electrolytic capacitor element, 2 ... ... Anode lead, 3,13 ... Anode external terminal, 4 ... Cathode layer, 5 ... Insulation layer, 6 ... Cathode external terminal, 7 ... Fuse wire, 8 ... Solder, 9 ... External resin.

Claims (1)

[Scope of utility model registration request] 1. A solid electrolytic capacitor having a plurality of cathode external terminals, wherein terminals having a symmetrical relationship with respect to a center of a drawing surface of the positive and negative external terminals have the same polarity.
The cathode layer of the surface opposite to the anode lead lead-out surface of the capacitor terminal is covered with an insulating material except for the central portion, and the cathode layer and a plurality of cathode external terminals are connected with a fuse across the insulating material. , A solid electrolytic capacitor with a fuse, which is insulated.