JPS62169316A - Manufacture of capacitor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a capacitor, and particularly to a method for manufacturing a capacitor including a multilayer capacitor chip.

[Prior Art] In order to obtain large capacitance with a small size, there is a capacitor of a multilayer type with a thickness of 1°. In this method, internal electrodes are formed between a plurality of dielectric layers, a pair of external electrodes are formed at opposing positions on the outer surface of a layer structure including a plurality of dielectric layers and internal electrodes, and The first group is connected to one external electrode, and the second group is connected to the other external electrode.

This allows a plurality of parallel-connected capacitances to be formed on one capacitor chip, and therefore a large capacity can be obtained despite the small size.

In order to use such a multilayer capacitor chip as a single capacitor component, lead wires are connected to its external electrodes. The lead wires are connected to the external electrodes by soldering. The capacitor chip to which the lead wires are connected is covered with an insulating exterior made of resin, glass, or the like.

[Problems to be Solved by the Invention] In such prior art, there is a problem in that reliability is particularly lacking in the soldering between the lead wire and the external electrode of the capacitor chip. More specifically, poor mechanical strength, low impact resistance, and poor moisture resistance were often observed.

Further, the process of soldering lead wires to a relatively small multilayer capacitor chip and the process of applying an insulating sheath to cover the multilayer capacitor chip after soldering are complicated.

Therefore, an object of the present invention is to provide a method for manufacturing a capacitor that can solve the above-mentioned problems.

[Means for Solving the Problems] The present invention is characterized by a method of providing external terminals corresponding to the conventional lead wires described above, which are connected to each external electrode of a multilayer capacitor chip. That is, such an external terminal is made of a conductive metal plate, has a plurality of comb teeth,
and each of the combs in the comb-shaped molded body, wherein a pair of connecting pieces are formed at the tips of two comb teeth selected from the plurality of comb teeth so that they approach each other. It is made to be obtained from the teeth. Note that the multilayer capacitor chip prepared in this invention is the same as the conventional one,
Internal electrodes are formed between each of the plurality of dielectric layers, a pair of external electrodes are formed at opposing positions on the outer surface of the layer structure including the plurality of dielectric layers and the internal electrodes, and a first Each group is connected to one external electrode and the second group is connected to the other external electrode.

After the multilayer capacitor chip and the comb-shaped molded body as described above are prepared, first, each external electrode of the multilayer capacitor chip is electrically connected to a pair of connection pieces included in the comb-shaped molded body by soldering. And mechanical connection is performed.

Then, the multilayer capacitor chip and the adjacent one
An insulating resin is formed to cover the pair of contact pieces. Next, two flat external terminals formed from independent comb teeth are provided by cutting the bases of the comb teeth provided in the comb-shaped molded body and separating each comb tooth from the comb-shaped molded body. , an independent capacitor is obtained.

[Example] FIG. 1 is a front view of a capacitor 1 obtained by implementing an example of the present invention. Figures 2 to 4 show the exterior resin 6 shown in Figure 1 removed, where Figure 2 is a plan view, Figure 3 is a left side view, and Figure 4 is a front view. . FIG. 5 is a cross-sectional structural diagram of the multilayer capacitor chip 2. As shown in FIG. FIG. 6 is a perspective view showing an intermediate stage of manufacturing the capacitor 1 of FIG. 1.

As shown in FIGS. 1 to 4, in the capacitor l, a pair of external electrodes 3 of a multilayer capacitor chip 2 are respectively connected to a pair of external terminals 5 by solder 4, and the multilayer capacitor chip 2 and its external terminals are connected to each other by solder 4. An exterior resin 6 is formed so as to cover the connecting portion with 5. At one end of the pair of external terminals 5, a pair of connecting pieces 7 shaped so as to approach each other is formed, and the multilayer capacitor chip 2 is placed on the pair of connecting pieces 7. solder in condition 4
Electrical and mechanical connections are made by For the detailed configuration of the multilayer capacitor chip 2, refer to FIG.
The detailed structure related to the external terminal 5 and the method of connecting the external terminal 5 will be described below with reference to FIG. 6.

Referring to FIG. 5, multilayer capacitor chip 2 includes a plurality of dielectric layers 8, and internal electrodes 9a and 9b are formed between each dielectric layer 8, respectively. These plurality of internal electrodes are divided into two groups 7 according to their formation mode, and the first group of internal electrodes 9a is the external electrode 3 on the left side of FIG.
(a), and the second group of internal electrodes 9b are respectively connected to the right external electrode 3(b). In this way, a large number of capacitances connected in parallel are formed between a pair of external electrodes 3 (a) and 3 (b), and a large capacity can be achieved despite the relatively small size. Obtainable.

With reference to FIG.
! 111.12. (The comb-shaped molded body 10 is integrally formed from a conductive metal plate. For example, a brass plate with a thickness of 0.25 to 0.3 mm is plated with tin or solder. The molded body 10 has first and second comb teeth 1.
The third comb teeth 13 are provided between 1.12 and 12. Although a particularly large number of teeth are not shown, three comb teeth 11°1
2.13 constitutes one set, and a large number of such sets are arranged in the molded body 10 in its length direction. Of these three comb teeth, the first and second comb teeth 11 are located on both sides.
12 are formed with mutually inwardly extending portions,
This corresponds to the contact piece 7 described above. This contact piece 7 is appropriately shaped and processed so as to stably receive the multilayer capacitor chip 2. Further, the third comb 13 located in the middle can mechanically clamp the multilayer capacitor chip 2 between the first and second comb teeth 11 and 12 due to the elasticity of the molded body 10. The molding has been processed. Therefore, until the solder 4 is applied, the multilayer capacitor chip 2 is elastically held between the first and second comb teeth 11, 12 on both sides and the third comb teeth 13 in the middle. As a result, it is held in the molded body 10. At this time, each external electrode 3 of the multilayer capacitor chip 2 comes into contact with each connecting piece 7 of the first and second comb teeth 11.12, and the other
The third tooth 13 is in contact with the surface of the multilayer capacitor chip 2 where the external electrode 3 is not provided.

As mentioned above, the comb teeth 11, 12, 13 of the molded body 10
The multilayer capacitor chip 2 is elastically held between the capacitors and is immersed in a solder bath or exposed to a jet of solder. As a result, the connecting piece 7 and the external electrode 3 are connected to the solder 4.
soldered by. Note that since the tips of the third comb teeth 13 are in contact with the surface of the multilayer capacitor chip 2 on which the external electrodes 3 are not formed, no solder is applied here.

Next, the third comb teeth 13 are cut at the position indicated by the dashed line 14 of the comb-shaped molded body 10.

This cutting of the third comb teeth 13 is particularly important since the multilayer capacitor chip 2 is already mechanically held by the solder 4 to the first and second comb teeth 11.12. It does not affect the retention status. Next, the exterior resin 6 is molded. For molding the exterior resin 6, the multilayer capacitor chip 2 is placed in a molding die.
This is done by putting the molded body 10 holding the mold and injecting resin into the mold. This resin may be molded by injection molding or low pressure transfer molding. Further, the exterior resin 6 may be formed by dipping it into an insulating resin. As a preferable resin constituting the outer bag resin 6, for example, phenol resin is selected. After the exterior resin 6 is molded in this way,
The first and second comb teeth 11.12 of the molded body 10 shown in FIG.

When cut in this way, the first and second comb teeth 11
．． 12 are separated from each other to form independent flat external terminals 5.

When the above steps are completed, an independent capacitor 1 having an appearance as shown in FIG. 1 is obtained. In this manner, the process of obtaining the capacitor 1 is extremely efficient because a large number of capacitors are held in one comb-shaped molded body 10. Note that, as shown in FIG. 6, the molded body 10
Through holes 15 are formed in the molded body 10, and these through holes 15 are distributed at equal intervals in the length direction of the molded body 10. These through holes 15 advantageously function for positioning or feeding in order to carry out the above-mentioned processes in a mechanically controlled manner.

In this embodiment, although not shown, the comb teeth 11.12
That is, the external terminal 5 and the comb teeth 13 may have a V-shaped cross section and be curved so that a ridge line appears in the length direction. With such a configuration, even if the molded body 10 is made of a thin plate, its strength against bending can be increased.

Note that the process of forming the solder 4 described above is performed on the third comb teeth 1.
3 with the multilayer capacitor chip 2 held, which was extremely efficient, but if such an advantage is not desired, the third comb teeth 13 can be eliminated and a suitable jig can be used instead. The solder 4 may be formed while the multilayer capacitor chip 2 is positioned using the multilayer capacitor chip 2.

FIG. 7 schematically shows an interesting mounting arrangement of a capacitor obtained by implementing the present invention. In the capacitor 1 shown here, a plurality of capacitors are in close contact with each other. This is a model showing the state in which it is mounted on a suitable board (not shown). This mounting arrangement state is advantageously realized because of the presence of the insulating exterior resin 6 and because the external terminals 5 are led out in the radial direction.

According to such a mounting arrangement state, a large number of capacitors 1 can be mounted on the board while occupying a small area.

FIG. 8 is a perspective view showing another example of the capacitor 1 shown in FIG. 1 at an intermediate stage of manufacture. This FIG. 8 corresponds to FIG. 6 described above. Therefore, parts corresponding to those shown in FIG. 6 are given the same reference numerals, and only the different structures will be described below.

As described above, the three comb teeth 11, 12, and 13 form one set, and a large number of such sets are arranged in the molded body 10 in its length direction. In the example shown in FIG. 8, a first comb tooth 11 and a second comb tooth 12 included in a set adjacent to the first comb tooth 11 are connected by a tie bar 16. This tie bar 16 is formed integrally with the molded body 10 and serves to reinforce the molded body 10. That is, when obtaining the comb-shaped molded body 10, the molded body 10 is punched out and formed integrally from a single conductive metal plate, but since this conductive metal plate is usually extremely thin, the molded body 10
is relatively weak. Therefore, during punching, the molded body 10 may be undesirably bent or dented, but the tie bars 16 advantageously prevent these from occurring. In addition, the molded body 1 is held while holding the multilayer capacitor chip 2.
0 is inserted into a mold for molding the exterior resin, but since the molded body 10 is relatively soft, the comb teeth 11°, 12.
The pitches of the pairs containing 13 often deviate from each other. In this case, resin molding cannot be carried out efficiently. However, as in this embodiment, the tie bar 1
6, the above-mentioned pitch deviation can occur, and therefore resin molding can be carried out efficiently. Note that it is preferable to inject the exterior resin after the ribber 16 is positioned in a mold for resin molding, cut and removed, and shaped into the shape shown in FIG. 6. .

[Effects of the Invention] As described above, according to the present invention, the external terminal is realized by the comb teeth formed as a part of the comb-shaped molded body made of a conductive metal plate. Since a connecting piece having a large area is formed and the connection with the external electrode of the multilayer capacitor chip is made in such a connecting piece, the reliability of the connection is high both electrically and mechanically. Therefore, first, a capacitor with increased mechanical strength and excellent impact resistance can be obtained. In addition, the presence of an insulating resin for the exterior makes it possible to obtain a capacitor with excellent moisture resistance, and together with the direction in which the external terminals lead out, such a capacitor can be mounted on a board with a small footprint. be able to implement it.

In addition, since the external terminal is realized by a plurality of comb teeth formed on a comb-shaped molded body, at the stage of cutting the base of such comb teeth to make an independent external terminal,
Operations such as soldering a plurality of multilayer capacitor chips can be performed all at once. Therefore, a large number of capacitors can be manufactured efficiently.

[Brief explanation of drawings]

FIG. 1 is a front view of a capacitor 1 obtained by implementing an embodiment of the present invention. 2 to 4 show the capacitor of FIG. 1 with the exterior resin 6 removed, in which FIG. 2 is a plan view, FIG. 3 is a left side view, and FIG. 4 is a front view. FIG. 5 is a cross-sectional structural diagram of the multilayer capacitor chip 2. As shown in FIG. FIG. 6 is a perspective view showing an intermediate stage of manufacturing the capacitor 1 of FIG. 1. FIG. 7 schematically shows the mounting arrangement of capacitors obtained by implementing the present invention. FIG. 8 is a perspective view showing another example of the capacitor shown in FIG. 1 at an intermediate stage of manufacture. In the figure, 1 is a capacitor, 2 is a multilayer capacitor chip, 3 is an external electrode, 4 is solder, 5 is an external terminal, 6 is an exterior resin, 7 is a connection piece, 8 is a dielectric layer, 9a and 9b are internal electrodes, 10 is a comb-shaped molded body, 11 is a first comb tooth, 1
2 is a second comb tooth, 13 is a third comb tooth, and 14 is a chain line indicating a cutting location.

Claims (2)

[Claims] (1) Internal electrodes (
9a, 9b) are formed, and the plurality of dielectric layers (8)
A pair of external electrodes (3) are formed at opposing positions on the outer surface of the layered structure including internal electrodes (9a, 9b), and the first group (9a) of the plurality of internal electrodes is one of the external electrodes. (3(a)) and the second group (9b) of the plurality of internal electrodes is connected to the other external electrode (3(b)).
a step of preparing a plurality of multilayer capacitor chips (2) connected to a plurality of comb teeth (11, 12) made of a conductive metal plate;
and a pair of connecting pieces (7) shaped so as to approach each other are formed at the tips of two comb teeth (11, 12) selected from the plurality of comb teeth. In addition, a step of preparing a comb-shaped molded body (10), and electrically and mechanically connecting each external electrode (3) of the multilayer capacitor chip (2) to the pair of connecting pieces (7) by soldering, respectively. and an insulating resin (6) covering the multilayer capacitor chip (2) and the pair of connection pieces (7) adjacent to the capacitor chip (2).
forming independent comb teeth by cutting the base of the comb teeth (11, 12) and separating each of the comb teeth (11, 12) from the comb-shaped molded body (10); (11,
12) obtaining an independent capacitor (1) having two flat external terminals (5) formed from the above. (2) The comb-shaped molded body (10) is a third comb located between two comb teeth (11, 12) connected to the external electrode (3) of the multilayer capacitor chip (2). Teeth (1
3), the third comb teeth (13) are connected to the capacitor chip (2);
), and due to the elasticity of the third comb teeth (13), the multilayer capacitor chip (
2) is sandwiched between the two comb teeth (11, 12), and the base of the third comb teeth (13) is sandwiched between the two comb teeth (11, 12) of the multilayer capacitor chip (2). 11
, 12), wherein the mechanical connection to the capacitor is made and then disconnected.