JPH06104150A - Solid electrolytic capacitor and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain a manufacturing method capable of stabilizing the characteristics and uniforming the lead pitch of a three-terminal type solid electrolytic capacitor having another lead of a different polarity in the middle of two leads having the same polarity. CONSTITUTION:Cathode leads 3a, 3a are extended in the same direction in parallel with each other from both the ends of a flat plate-shaped lead connecting portion 3b; one anode lead 4 is arranged in the intermediate position between said two cathode leads; an anode pin 2 fixed to a capacitor element 1 is welded to one end portion of the anode lead 4; one side of a square type capacitor element 1 is connected to a metal flat plate type lead connecting portion 3b of the cathode leads 3a, 3a with a conductive adhesive 5 and the vicinity of the capacitor element 1 is covered with an armor resin 6. The two cathode leads 3a, 3a on both the sides are part of a lead frame formed punched from a metal flat plate; by using this lead frames, the arrangement pitch of 3 terminal leads can be made constant and a three-terminal type solid electrolytic capacitor can be produced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-terminal solid electrolytic capacitor having a cathode lead and an anode lead, and a method for manufacturing the same.

[0002]

2. Description of the Related Art A two-terminal type solid electrolytic capacitor having one anode lead and one cathode lead is mounted on a printed circuit board by mounting an anode mounting hole and a cathode mounting hole at two positions on the printed circuit board. Is performed by inserting the corresponding anode lead and cathode lead. However, during this mounting, there is a risk of reverse mounting in which the polarities of the two leads are mistakenly inserted into the mounting holes of the printed board and soldered as it is.

Therefore, a three-terminal type solid electrolytic capacitor as shown in FIGS. 6 (a) and 6 (b) has been put into practical use as a solid electrolytic capacitor for avoiding the risk of reverse mounting. In this, one anode lead (18) and two cathode leads (17) (17) are connected to the capacitor element (1 ′), and the main part including the capacitor element (1 ′) is covered with an exterior resin material (6). '). Cathode leads (17) (17) are arranged in parallel at a constant pitch P on both sides of the anode lead (18).

The capacitor element (1 ') is formed by pressing metal powder having a valve action such as tantalum into a cylindrical shape around a metal anode pin (2') having the same valve action and sintering it. It is formed. This capacitor element (1 ')
Is subjected to chemical conversion treatment or the like to form a cathode electrode extraction layer on its surface. The anode lead (18) is welded to the anode pin (2 '), and the cathode leads (17) (17) are connected to the surface of the capacitor element (1') with solder (19).

The two cathode leads (17) (17) are both end portions of one metal wire (17 ') bent and formed in a substantially U shape. The center of the metal wire (17 ') is a lead connecting part (17b) bent in a semicircle, and this lead connecting part (17b) is soldered to the outer periphery of the capacitor element (1') by a solder dip method. .

The three-terminal type solid electrolytic capacitor of FIG. 6 is mounted on a printed circuit board (20) as shown in FIG. The printed circuit board (20) has three mounting holes (21) ~
(23) has a constant pitch P. The central mounting hole (22) is for the anode, and the mounting holes (21) (23) on both sides are for the electrically connected cathode. The solid electrolytic capacitor is mounted on the printed circuit board (20) by inserting three lead terminals into the corresponding three mounting holes (21) to (23) and soldering on the back surface of the printed circuit board (20). . At this time, even if the horizontal mounting angle of the solid electrolytic capacitor is reversed by 180 °, the polarities of the left and right leads (17) and (17) are the same. Loss of nature.

The above-mentioned three-terminal type solid electrolytic capacitor has, for example, first and second chain leads (24) as shown in FIG.
It is manufactured in the state of (26). 1st chain lead (24)
Is the anode lead (1
The tip of 8) is connected and integrated with a long metal holder (25). The second chain leads (26) are holders (27) made of long paper such that the tip portions of each of the two cathode leads (17) (17) in a plurality of pairs of solid electrolytic capacitors.
It is connected with.

The anode pin (2 ') of the capacitor element (1') is welded to each anode lead (18) of the first chain lead (24). 2 for each of the second chain leads (26)
The capacitor element (1 ') is fitted to the lead connecting portion (17b) of the cathode leads (17) (17) of the book, and the first and second chain leads (24) (26) are positioned and superposed. The capacitor element (1 ') is soldered and the capacitor element (1') and the lead connecting portion (17b) are soldered. Further, as shown by the chain line in FIG. 8, each capacitor element (1 ′) is coated with the exterior resin material (6 ′) by a dip method.

When a plurality of solid electrolytic capacitors are manufactured in the state of FIG. 8, first and second chain leads (24) (26)
The holders (25) (27) are cut and removed to become individual solid electrolytic capacitors, which are commercialized.

[0010]

The above three-terminal type solid electrolytic capacitor is manufactured with a constant pitch P between the tip of the anode lead (18) in the center and the two cathode leads (17) (17) on both sides. Therefore, the tips of the leads are supported by the corresponding holders (25) (27). However, the pitch error between the tips of the two cathode leads (17) and (17) in the holder (25) and the two holders (25) and (27)
Due to the positional deviation of the above, the pitch P between the tips of the leads in the commercialized solid electrolytic capacitor may vary.

Thus, the pitch P between the three terminal lead tips is
If there are variations, the three leads (17) (18) (17) corresponding to the three mounting holes (21) to (23) drilled at a constant pitch P in the printed circuit board (20) are automatically inserted. Therefore, it becomes difficult to automatically mount the solid electrolytic capacitor.

In addition, the cathode lead (17) (17) which is approximately U
The lead connecting part (17b) at the center of the letter-shaped metal wire (17 ') and the capacitor element (1') are wire-contacted for solder connection, but such a connection form has low mechanical strength and electrical connection. There was a problem with poor physical connectivity. In addition, the lead connecting part (17
During solder dipping of b) and the capacitor element (1 '), the capacitor element (1') is subjected to high temperature thermal stress of about 250 ° C or more, and this thermal stress also causes a problem that the characteristics of the capacitor element (1 ') are deteriorated. there were.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a three-terminal solid electrolytic capacitor having a constant pitch of three-terminal leads and stable characteristics, and a manufacturing method thereof. To provide.

[0014]

SUMMARY OF THE INVENTION According to the present invention, of three external lead-out leads extending in parallel in the same direction at a constant pitch from a capacitor element made of a metal having a valve action, the central one is an anode or a cathode. Lead, 2 on each side is 1
A three-terminal type solid electrolytic capacitor in which the main part including the capacitor element is covered with an exterior resin material, and the two ends are the same end. The above object is achieved by adopting a structure in which the cathode lead is integrally connected to the lead connecting portion of the metal flat plate, and the lead connecting portion is connected to the capacitor element by a conductive adhesive.

Further, according to the present invention, the two same-polarity leads on both sides are anode leads and the central one is a cathode lead, and the flat end of the cathode lead is connected to the capacitor element by a conductive adhesive. Even with the above structure, the above object can be achieved.

Further, according to the present invention, in order to manufacture the above-mentioned solid electrolytic capacitor with a constant tip pitch of each lead, at least two leads having the same polarity on both sides of the three leads are punched and formed on a metal flat plate. As a part of the frame, the capacitor element is connected to each lead in the state of this lead frame, the main part including the capacitor element is coated with the exterior resin material, and then each lead is separated from the lead frame. And

[0017]

When the two lead wires on both sides are cathode leads and the lead connecting portion of the metal flat plate is connected to the capacitor element by a conductive adhesive, the capacitor element and the lead connecting portion are in surface contact with each other to increase the mechanical strength of both. In addition, the capacitor element is not subjected to thermal stress and the characteristics are stable. Further, even when the central one is a cathode lead and the flat end thereof is connected to the capacitor element with a conductive adhesive material, the capacitor element and the cathode lead are in surface contact with each other to increase the mechanical strength of both, and The characteristics are stable without heat stress being applied to the capacitor element.

At least two leads of the same polarity on both sides are a part of the lead frame. The lead frame is used to connect the capacitor elements and coat the outer resin material, and then separate the leads from the lead frame. By doing so, the tip pitch of the three-terminal leads can be accurately kept constant in the lead frame, and a solid electrolytic capacitor with a high lead pitch accuracy can be manufactured.

[0019]

Embodiments of the present invention will be described below with reference to FIGS. 1 shows the three-terminal solid electrolytic capacitor of the first embodiment, FIG. 2 shows the three-terminal solid electrolytic capacitor of the second embodiment, and FIGS. 3 to 5 show these three-terminal solid electrolytic capacitors. The same reference numerals are given to the same or corresponding portions throughout the drawings.

The solid electrolytic capacitor of the first embodiment shown in FIGS. 1 (a) to 1 (c) has two cathode leads (3a).
(3a) and one anode lead (4). The two cathode leads (3a) (3a) are stamped and formed into a substantially U-shaped metal flat plate, and the lead connecting portion (3
From both ends of b), two cathode leads (3a) (3a) extend in parallel in the same direction. Two cathode leads (3a) (3
One anode lead (4) is arranged in the middle of a).

An anode pin (2) set up in the capacitor element (1) is welded to one end of the anode lead (4). The capacitor element (1) is, for example, a rectangular type, and the lead connecting portion (3b) of the cathode leads (3a) (3a) is connected to one side surface thereof with a conductive adhesive material (5) such as Ag paste.

The two cathode leads (3a) (3a) are shown in FIG.
The lead frame (7) is formed as described later.
The lead connecting portion (3b) of the cathode lead (3a) (3a) is
It is a gate-shaped metal flat plate that extends over the side surface and the top surface of the capacitor element (1), and integrally has an L-shaped bent piece (3c) that partially opposes one side surface of the capacitor element (1). The capacitor element (1) is inserted between the lead connecting portion (3b) and the bending piece (3c), and the capacitor element (1) and the bending piece (3c) are connected by a conductive adhesive (5). It

The solid electrolytic capacitor of FIG. 1 is manufactured by using the lead frame (7) shown in FIG. 3 and the chain lead (16) shown in FIG. The lead frame (7) shown in FIGS. 3 (a) and 3 (b) is formed by connecting the tips of two pairs of cathode leads (3a) (3a) of a plurality of solid electrolytic capacitors with a tie bar (8) made of the same metal. It was done. The tip pitch P'of the pair of cathode leads (3a) (3a) in the lead frame (7) is equal to the tie bar (8).
It is regulated to some extent by the consolidation of.

The chain lead (16) of FIG. 4 is similar to that of FIG. 8, and the tip ends of the anode leads (4) of a plurality of solid electrolytic capacitors are connected to a long holder (15) at a constant pitch. There is. The anode pin (2) of the capacitor element (1) is welded to each anode lead (4) of this chain lead (16) in the same manner as in the conventional method, and the chain lead (1
6) and the lead frame (7) are positioned and overlapped, and the capacitor element (1) is connected to the lead connecting portion (3b) of the cathode leads (3a) (3a) with a conductive adhesive (5).

The connection between the capacitor element (1) and the lead connecting portion (3b) by the conductive adhesive material (5) is 1
The heat treatment at 50 ° C. or lower can be performed sufficiently satisfactorily and without applying thermal stress to the capacitor element (1).
Also, a bent piece (3c) of the flat lead connecting portion (3b)
And one side surface of the rectangular capacitor element (1) are connected in surface contact with each other, the effective connection area of both increases,
A good electrical and mechanical connection is always possible.

The lead frame (7) and the chain lead (16) in the state shown in FIG. 4 are erected so that the capacitor element (1) faces downward, the capacitor element (1) is immersed in a molten resin, and the capacitor element (1) is pulled up. The exterior resin material (6) is formed on the periphery of (1). Thereafter, a characteristic inspection or the like is performed, and the tie bar (8) of the lead frame (7) and the holder (15) of the chain lead (16) are cut and removed to obtain the solid electrolytic capacitor shown in FIG. The pitch P of the three-terminal leads of this solid electrolytic capacitor
Is kept constant by regulation by the tie bar (8) of the lead frame (7) and the holder (15) of the chain lead (16).

The solid electrolytic capacitor of the second embodiment shown in FIGS. 2 (a)-(c) has two anode leads (9a).
(9a) and one cathode lead (10). The two anode leads (9a) (9a) are stamped and formed into a substantially U-shaped metal flat plate, and the two anode leads (9a) are provided from both ends of the lead connecting portion (3b) of the metal flat plate at the center. (9a) extends in parallel in the same direction, and one cathode lead (10) is arranged in the middle. The cathode lead (10) is also a stamped and formed metal flat plate, and has an L-shaped flat end (10a) at one end facing one side surface of the rectangular capacitor element (1).

The anode pin (2) set up in the capacitor element (1) is welded to the central one side of the flat lead connecting portion (3b) of the anode leads (9a) (9a), and the anode pin (2) of the capacitor element (1) is welded. One side surface is connected to the flat end (10a) of the cathode lead (10) with a conductive adhesive material (5) such as Ag paste. After this connection, the main part around the capacitor element (1) is covered with the exterior resin material (6).

The solid electrolytic capacitor shown in FIG. 2 is, for example, as shown in FIG.
It is manufactured using the lead frame (11) shown in (a) and (b). The lead frame (11) is formed by connecting the respective tips of two anode leads (9a) (9a) and one cathode lead (10) of a plurality of solid electrolytic capacitors with a tie bar (12). The capacitor element (1) is connected to the flat end (10a) of the cathode lead (10) of this lead frame (11) with a conductive adhesive (5), and the anode pin (2) of the capacitor element (1) is connected. Anode lead (9
a) Welding to the lead connecting part (9b) of (9a), the exterior resin material (6) is formed by the dip method. Then, the tie bars (12) of the lead frame (11) are cut and separated to obtain a plurality of solid electrolytic capacitors.

In the case of the lead frame (11) of FIG. 5, the tie bar (12) regulates the tip pitch P of the three-terminal leads of one solid electrolytic capacitor to a constant value, so the pitch P of the three-terminal leads is more stable. Obtained. Also in this case, the contact area between the capacitor element (1) and the cathode lead (10) can be increased, and the electromechanical connectivity between them can be improved.

The present invention is not limited to the above embodiment, but the following modifications are possible, for example.

In the case of the solid electrolytic capacitor of FIG. 1, one anode lead is formed with the same lead frame together with two cathode leads. For the anode lead of this lead frame,
The anode pin of the capacitor element is welded.

The capacitor element of the solid electrolytic capacitor shown in FIGS. 1 and 2 is not limited to the rectangular type, but may be a cylindrical type. In this case, the flat plate-shaped connecting portion of the lead, which is connected to the cylindrical capacitor element with a conductive adhesive, has a semicircular cross section.

Although the exterior resin material of the solid electrolytic capacitor shown in FIGS. 1 and 2 is formed by the dipping method, it may be formed by a molding method using a die. That is, when at least two lead wires on both sides of the three-terminal lead are used as the lead frame, it becomes easy to clamp the lead frame with the mold and accurately position the capacitor element in the cavity of the mold, and to improve the resin exterior material. It can be resin-molded.

[0035]

According to the present invention, since the flat plate portions of the cathode leads, which are two on each side or one in the center, are connected to the capacitor element by the conductive adhesive, the electrical and mechanical connectivity between the capacitor element and the cathode lead is improved. Always good, and
A thermal stress is not applied to the capacitor element, and therefore, a three-terminal solid electrolytic capacitor having stable characteristics and good yield can be provided.

At least two leads of the same polarity on both sides are a part of the lead frame, and the lead frame is separated from the lead frame after connecting the capacitor element and coating the exterior resin material. As a result, the tip pitch of the three-terminal leads during manufacture is always kept constant in the lead frame, and the lead pitch is constant, so that a solid electrolytic capacitor advantageous for automatic mounting on a printed circuit board can be manufactured.

[Brief description of drawings]

1A is a sectional view showing a first embodiment of a solid electrolytic capacitor according to the present invention, and FIG. 1B is a sectional view taken along line AA of FIG. 1A.
Sectional drawing which follows the line, (c) is sectional drawing which follows the BB line of Fig.1 (a).

2A is a sectional view showing a second embodiment of the solid electrolytic capacitor according to the present invention, and FIG. 2B is a sectional view taken along line CC of FIG. 2A.
Sectional drawing which follows the line, (c) is sectional drawing which follows the DD line of Fig.2 (a).

3 (a) is a partial plan view of a lead frame used for manufacturing the solid electrolytic capacitor of FIG. 1, and FIG. 3 (b) is FIG.
Sectional drawing which follows the EE line of (a).

4 is a partial plan view of a manufacturing intermediate structure of a solid electrolytic capacitor using the lead frame of FIG.

5A is a partial plan view of a lead frame used for manufacturing the solid electrolytic capacitor of FIG. 2, and FIG.
Sectional drawing which follows the FF line of (a).

6A is a cross-sectional view of a conventional three-terminal solid electrolytic capacitor, and FIG. 6B is a cross-sectional view taken along the line GG of FIG. 6A.

7 is a sectional view of the solid electrolytic capacitor of FIG. 6 mounted on a printed board.

8 is a partial plan view of a chain lead for manufacturing the solid electrolytic capacitor of FIG.

[Explanation of symbols]

 1 Capacitor element 3a Two cathode leads on both sides 3b Lead connecting part 3c Bent piece 4 Anode lead in the center 5 Conductive adhesive 6 Exterior resin material 7 Lead frame 8 Tie bar 9a Two anode leads on both sides 9b Lead connecting part 10 1 cathode lead in the center 10a Flat end 11 Lead frame 12 Tie bar

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[Procedure amendment]

[Submission date] December 1, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction content]

The above-mentioned three-terminal type solid electrolytic capacitor has, for example, first and second chain leads (24) as shown in FIG.
It is manufactured in the state of (26). 1st chain lead (24)
Is the anode lead (1
The tip of 8) is connected and integrated with a long metal holder (25). The second chain lead (26) is formed by connecting the tip ends of each two cathode leads (17) (17) in a plurality of pairs of solid electrolytic capacitors with a long metal holder (27).

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Name of item to be corrected] Fig. 4

[Correction method] Change

[Correction content]

[Figure 4]

[Procedure 3]

[Document name to be corrected] Drawing

[Correction target item name] Figure 8

[Correction method] Change

[Correction content]

[Figure 8]

Claims (3)

[Claims] 1. Out of three lead-out leads extending in parallel in the same direction at a constant pitch from a capacitor element made of a metal having a valve action, one in the center is an anode or cathode lead and two on both sides are A three-terminal solid electrolytic capacitor having a pole different from the one lead and having a capacitor element covered with an outer resin material. A solid electrolytic capacitor, characterized in that a cathode lead whose ends are integrally connected by a lead connecting part having a flat metal plate shape, and the lead connecting part of the cathode lead is connected to a surface of a capacitor element by a conductive adhesive. 2. Out of three lead-out leads extending in parallel in the same direction at a constant pitch from a capacitor element made of a metal having a valve action, one in the center is an anode or cathode lead and two on both sides are A three-terminal type solid electrolytic capacitor in which a main part including a capacitor element is a same-polarity lead having a different pole from the one lead, and a two-sided two-polarity lead is a flat metal plate. In the solid electrolytic capacitor, one in the center is a metal plate-shaped cathode lead, and the plate-shaped end portion of the cathode lead is connected to the surface of the capacitor element with a conductive adhesive. 3. A part of a lead frame in which at least two same-polarity leads on both sides of the solid electrolytic capacitor according to claim 1 and 2 are connected and integrated by a tie bar made of the same metal at the tip end opposite to the lead connection part. In this lead frame state, a capacitor element is connected to each of the three leads, a main part including the capacitor element is coated with an exterior resin material, and then the tie bar of the lead frame is cut and removed. Manufacturing method of solid electrolytic capacitor.