JP3437639B2 - Structure of surface mount type solid electrolytic capacitor with thermal fuse and method of manufacturing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a solid electrolytic capacitor such as a tantalum solid electrolytic capacitor or an aluminum solid electrolytic capacitor, which is equipped with a temperature fuse that melts when the temperature rises, and a structure thereof. It relates to a manufacturing method.

[0002]

2. Description of the Related Art Conventionally, a surface mount type solid electrolytic capacitor provided with a thermal fuse is disclosed in, for example, Japanese Patent Laid-Open No. 10551/1990.
As shown in FIG. 7 of the publication No. 3 and the like, a capacitor element 1 including a capacitor chip piece 1a and an anode rod 1b protruding from the capacitor chip piece 1a is
Between the pair of left and right lead terminals 2 and 3 made of a metal plate, the anode rod 1b of the capacitor element 1 is arranged so as to be fixed to one anode side lead terminal 2, and the capacitor chip piece of this capacitor element 1 is arranged. 1a and the other cathode-side lead terminal 3 are connected by a temperature fuse wire 4 such as a solder wire, and then the whole of them is packaged by a molded part 5 made of synthetic resin. , 3 is bent to the lower surface side of the mold part 5.

[0003]

Since the conventional surface mount type solid electrolytic capacitor with a thermal fuse has the above-mentioned structure, the overall length L'is equal to the length of the capacitor element 1. Anode rod 1 in capacitor element 1
The length required to connect the anode side lead terminal 2 to b and the length required to connect the capacitor chip piece 1a in the capacitor element 1 and the cathode side lead terminal 3 with the temperature fuse wire 4 are added. On the other hand, the overall height dimension H'includes the height dimension of the capacitor element 1, the height dimension of the temperature fuse wire 4 protruding from the upper surface of the capacitor chip piece 1a, and the molding of both lead terminals 2 and 3. The bending dimension of the portion 5 to the lower surface side is added.

That is, in the conventional surface mount type solid electrolytic capacitor with a thermal fuse, both the total length dimension L'and the total height dimension H'become large, which causes the increase in capacity. Not only there is a problem that it is a great hindrance, but there is also a problem that the weight greatly increases because both lead terminals 2 and 3 made of a metal plate are used.

Moreover, in the conventional surface mount type solid electrolytic capacitor with a thermal fuse, the capacitor chip piece 1
In addition to requiring a great deal of work to connect the a and the cathode side lead terminal 3 with the thermal fuse wire 4, both lead terminals 2 and 3 made of a metal plate are required and used, Further, since it is necessary to bend both the lead terminals 2 and 3, the manufacturing process is complicated, the manufacturing cost is significantly increased, and the defective product rate is high.

It is a technical object of the present invention to provide a structure of a surface mount type solid electrolytic capacitor with a temperature fuse which solves these problems and a method of manufacturing the same.

[0007]

In order to achieve this technical object, the present invention provides a "capacitor element having a capacitor chip piece and an anode rod protruding from one end surface of the capacitor chip piece, which is made of synthetic resin. In a solid electrolytic capacitor packaged in a mold part, a recess is provided in one end surface of the mold part, and the anode rod is projected into the recess, and a film-shaped thermal fuse is provided. While inserting to connect to the anode rod,
A cathode side terminal electrode film is formed on the other end surface of the mold part so that the cathode side terminal electrode film is connected to the capacitor chip piece, and further, an anode side terminal electrode film is formed on one end surface of the mold part. The anode side terminal electrode film is formed so as to be connected to the thermal fuse. "."

In the manufacturing method of the present invention, a synthetic resin mold part for packaging a capacitor element having a capacitor chip piece and an anode rod protruding from one end surface of the capacitor chip piece is formed by While forming a recess in which the anode rod protrudes on the end face, a step of molding so that the other end face of the capacitor chip piece is exposed at the other end face of the mold part, and then a film-shaped thermal fuse is formed in the recess. And a step of forming an anode-side terminal electrode film on one end surface of the mold part and a cathode-side terminal electrode film on the other end surface thereof. ”

[0009]

[Operation] By configuring in this way, it is possible to omit both metal plate lead terminals and thermal fuse wires that have been used in the past.
While it is possible to prevent the length required to connect the lead terminal to the anode rod and the length required to connect the capacitor chip piece and the lead terminal with the temperature fuse wire from being added, the overall height dimension In addition, it is possible to prevent the height of protrusion of the capacitor chip piece from the upper surface of the thermal fuse wire and the bending dimension of the mold portion of both lead terminals to the lower surface side from being added, unlike the conventional case. The size and overall height can be significantly reduced.

Further, according to the manufacturing method of the present invention, it is not necessary to connect the temperature fuse wire as in the conventional case,
Moreover, the lead terminals made of a metal plate and the bending process thereof are not required, and after the molding of the molding portion, simply load a film-shaped thermal fuse in the recess on one end surface of the molding portion, Since it suffices to form the terminal electrode film on each of them, the process is extremely simple and the rate of defective products can be surely reduced.

[0011]

As described above, according to the present invention, the solid electrolytic capacitor with a temperature fuse can be downsized to have a large capacity and can be reduced in weight. In addition, according to the manufacturing method of the present invention, the manufacturing process is simple and the incidence of defective products is low, so that the manufacturing cost can be significantly reduced.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to the drawings of FIGS. In this figure, reference numeral 11 indicates a capacitor chip piece 11a and this capacitor chip piece 11a.
2 shows a capacitor element including an anode rod 11b protruding from one end surface 11a 'of the.

Reference numeral 12 indicates the capacitor element 1
1 shows a mold part made of synthetic resin for packaging 1. When molding the mold part 12 with a synthetic resin, a recess 13 is provided on one end face 12a of the mold part 12 while the mold part 12 is molded. The other end surface 11a ″ of the capacitor chip piece 11a is exposed on the other end surface 12b.

Then, the anode rod 11b of the capacitor element 11 is projected into the recess 13 in the one end face 12a of the mold portion 12, and the film-shaped thermal fuse 14 is inserted into the recess 13 and the anode rod 11b. It is loaded so as to be electrically connected to 11b and is filled with a soft elastic resin 15 such as a silicone resin. When the thermal fuse 14 is electrically connected to the anode rod 11b, a conductive adhesive or a metal paste such as silver paste is used for the connection therebetween. By using these conductive adhesives or metal pastes, the thermal fuse 14 can be connected to the anode rod 11.
It is possible to surely connect to b, and by filling the recess 13 with a soft elastic resin 15 such as a silicone resin,
The certainty of fusing at temperature can be ensured.

On one end surface 12a of the mold portion 12, for example, a metal paste layer 16a such as a silver paste which is applied so as to be in close contact with the thermal fuse 14,
The anode side terminal electrode film 16 is formed from the nickel plating layer 16b applied to the surface of the metal paste layer 16a, the solder layer 16c applied to the surface of the nickel plating layer 16b, and the other end surface of the mold portion 12 is formed. 12b
For example, a metal paste layer 17a such as a silver paste which is applied so as to be in close contact with the other end surface 11a ″ of the capacitor chip piece 11a, a nickel plating layer 17b applied to the surface of the metal paste layer 17a, and The cathode side terminal electrode film 17 is formed from the solder layer 17c or the like applied to the surface of the nickel plating layer 17b.

With this structure, the overall length L is equal to the length of the capacitor element 11.
The total length dimension L can be greatly reduced as compared with the conventional case, while the total thickness dimension of the both terminal electrode films 16 and 17 is added, and the overall height dimension H can be reduced.
Is a capacitor chip piece 1 in the capacitor element 11.
The thickness of the mold portion 12 may be added to the height dimension of 1a, and the overall height dimension H can be significantly reduced as compared with the conventional case. The solid electrolytic capacitor can be significantly downsized and its capacity can be increased.

Further, in the manufacture thereof, the capacitor element 11 is loaded into a mold for molding the mold portion, and the mold portion 12 is attached to the one end surface 12a of the mold portion 12 as shown in FIG. Molding is performed such that the recess 13 from which the protrusion 11b projects is provided, while the other end surface 12b of the mold portion 12 exposes the other end surface 11a ″ of the capacitor chip piece 11a.

Next, as shown in FIG. 5, a thermal fuse 14 is loaded into the recess 13 of the mold portion 12, and then a soft elastic resin 15 is loaded. And FIG.
As shown in FIG.
By coating the metal paste on both a and the other end surface 12b and then drying, the metal paste layers 16a, 16a, 1
7a, and then both metal paste layers 16a,
After nickel plating layers 16b and 17b are formed on the surface of 17a by nickel plating, solder layers 16c and 17c are formed on the surfaces of both nickel plating layers 16b and 17b by solder plating or the like.

According to this manufacturing method, after the molding portion 12 is molded, a film-shaped thermal fuse 14 is loaded in the recess 13 in the one end face 12a of the molding portion 12, and the soft elastic resin 15 is formed.
After filling the
Since the terminal electrode films 16 and 17 are formed on the a and 12b, respectively, the process is so simple that it is incomparable to the conventional case, and the rate of defective products can be greatly reduced.

[Brief description of drawings]

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

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a perspective view of a solid electrolytic capacitor according to an embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a state in which a capacitor element is packaged in a mold part.

FIG. 5 is a cross-sectional view showing a state in which a thermal fuse is loaded in the recess of the mold part.

FIG. 6 is a cross-sectional view showing a state in which a metal paste layer is formed on both end surfaces of a mold part.

FIG. 7 is a vertical sectional front view of a conventional solid electrolytic capacitor with a temperature fuse.

[Explanation of symbols]

11 Capacitor element 11a Capacitor chip piece 11b Anode rod 12 Mold part 13 recess 14 Thermal fuse 15 Soft elastic resin 16 Anode side terminal electrode film 17 Cathode side terminal electrode film

Claims (2)

(57) [Claims] 1. A solid electrolytic capacitor in which a capacitor element having a capacitor chip piece and an anode rod projecting from one end surface of the capacitor chip piece is packaged in a synthetic resin mold part, wherein one of the mold parts is formed. The end face is provided with a recess, and the anode rod is projected into the recess, and a film-shaped thermal fuse is inserted so that the thermal fuse is connected to the anode rod, while the other end face of the mold portion is inserted. A cathode side terminal electrode film is formed so that the cathode side terminal electrode film is connected to the capacitor chip piece, and further, an anode side terminal electrode film is formed on one end surface of the mold part. Is formed so as to be connected to the thermal fuse, and the structure of a surface mount type solid electrolytic capacitor with a thermal fuse. 2. A mold part made of synthetic resin for packaging a capacitor element having a capacitor chip piece and an anode rod projecting from one end surface of the capacitor chip piece, the anode rod projecting to one end surface of the mold portion. A step of forming a recess so that the other end surface of the capacitor chip piece is exposed at the other end surface of the mold part, then a step of loading a film-like thermal fuse in the recess part, and then the above step And a step of forming an anode-side terminal electrode film on one end surface of the mold portion and a cathode-side terminal electrode film on the other end surface thereof, respectively.