JPS6013297B2 - Manufacturing method of solid electrolytic capacitor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a face bonding type solid electrolytic capacitor without lead wire terminals, and more specifically, a method for manufacturing a face bonding type solid electrolytic capacitor with high dimensional accuracy and easily. The present invention provides a method for manufacturing.

Conventionally, face bonding type solid electrolytic capacitors use a dielectric oxide film formed on the surface of a solidified body of valve metal powder such as tantalum to serve as an anode body, and then a dielectric oxide film is formed on the dielectric oxide film of the anode body. A capacitor element is constructed by sequentially laminating a semiconductor layer such as manganese dioxide, a cathode layer such as carbon, and a cathode current collecting layer such as silver paint and solder.
A solderable metal terminal serving as an anode is connected to a protruding lead-in wire made of the same material as the anode body drawn out from the anode body of the capacitor element to obtain a completed product.

A typical example is shown in FIG. 1, where 1 is a capacitor element, 2 is a semiconductor layer, 3 is a cathode conductive layer, 4 is a protruding lead-in line, and 5 is a metal terminal.

By the way, when the metal terminal 5 is connected to the protruding lead-in wire 4 of the capacitor element 1 by welding in the manufacture of solid electrolytic capacitors, if the root part of the protruding lead-in wire 4 of the capacitor element 1 is subjected to mechanical stress, leakage current increases. Therefore, at present, the metal terminal 5 is welded with the base part as far away as possible.

However, in such a method, the capacitor element 1
Since the gap between the metal terminal 5 and the metal terminal 5 becomes wide, it is difficult to fill the gap by pouring resin for reinforcement, to eliminate dripping of the resin to form a rectangular shape, and to improve dimensional accuracy. there were.

The present invention has been made in view of such conventional problems, and the method for manufacturing a solid electrolytic capacitor according to the present invention will be explained below with reference to the drawings.

Figure 2 shows the manufacturing process of a solid electrolytic capacitor according to an embodiment of the present invention. The capacitor element 10 is constructed by sequentially laminating a semiconductor layer such as manganese dioxide, a cathode layer such as carbon, and a cathode conductive layer such as silver paint or solder on the oxide film.

Thereafter, a resin such as epoxy resin, which has good adhesion to metal and heat resistance, is applied to the base of the protruding lead-in wire 11 of the capacitor element 10 and hardened.
form 2. Then, a metal terminal 13 of iron, nickel, or the like, which will serve as an anode, is brought into contact with the raised portion 12 and connected to the root portion of the protruding lead-in wire 11 by welding. At this time, the metal terminal 13 can be connected close to the capacitor element 10 by the raised portion 12. The capacitor element 1
The resin applied to the base of the protruding lead-in wire 11 of 0 is a filler.
If a mixture of these is used, the adhesion strength with the metal will decrease, so it is preferable to use one that does not contain filler, but for practical purposes, either will do.

The thickness of the resin applied depends on the size of the capacitor element 10, but is 0.1 to 1. If it is only a slight amount, it is sufficient to prevent stress during welding.

This raised portion 12 made of resin insulates between the capacitor element 10 and the metal terminal 13, and
This is to prevent the characteristics of the capacitor element 10 from deteriorating due to stress even if the capacitor element 10' is brought close to the capacitor element 10' and connected by welding. In other words, the resin bulge 12 allows the metal terminal 13 to be connected one distance from the capacitor element. By the way, the surface of the raised portion 12 made of resin becomes arcuate due to surface tension, so when the metal terminal 13 is connected to the protruding lead-in wire 11 by touching the raised portion 12, the raised portion A gap of about 1.0 skin at maximum is created between the surface of the metal terminal 12 and the metal terminal 13.

In this state, capacitor element 10 and metal terminal 1
3 is connected only by the thin protruding lead-in wire 11, so when automatic alignment and automatic feeding are performed using a parts feeder or the like, the protruding lead-in wire 11 may be bent and the metal terminal 13 may be distorted.

Therefore, after connecting the metal terminal 13 to the protruding lead-in wire 11,
A resin 14 is filled into the gap between the resin raised portion 12 and the metal terminal 13 and hardened.

As a result, the capacitor element 10, the protruding lead-in wire 11,
The metal terminal 13 is integrated with the protruding lead-in wire 1 as described above.
1 is bent and the metal terminal 13 is not distorted. Also, at this time, the raised portions 1 2 and the metal terminals 1 3
The gap between is 1. Since the width is narrower than the W rib, the resin 14 can be cured without dripping. Thereafter, the end of the capacitor element 10 on the side opposite to the protruding lead-in wire 11 side, which will become the cathode, is left open and a heat-resistant insulating resin 15 such as epoxy, silicon, or phenol is used to form the capacitor element 10. The finished product is made by covering the middle part.

The coating with the resin 15 protects the capacitor element 10 and provides insulation between the anode and the cathode when a conductive part of an electric circuit is present below during use. Note that the coating with the resin 15 and the filling with the resin 14 may be performed simultaneously using the same type of material. The width of the anode and cathode is preferably 1/3 to 1/9 degrees Fahrenheit of the total length of the capacitor, and the polarity can be determined by making a difference in the width of the anode and cathode terminals. Good too.

The cathode may remain a conductive paint layer such as silver paint, but
Coating solder on top of that is superior in terms of solderability, mechanical strength, and moisture resistance during soldering. 3 to 5 show face bonding type solid electrolytic capacitors obtained by the manufacturing method of the present invention. In the solid electrolytic capacitors shown in FIGS. 3a, b, and c, the flat part of the metal terminal 13 connected to the protruding lead-in wire 11 is not covered with resin 14, and 16 is a solder which becomes the cathode. It is a layer.

In the solid electrolytic capacitors shown in FIGS. 4a, b, and c, the flat portion of the metal terminal 13 connected to the protruding lead-in wire 11 is also covered with a resin 14.

In addition, the group electrolytic capacitors shown in Fig. 5 a, b, and c are as follows:
The upper metal terminal 13a and the lower metal terminal 13b are connected to the protruding lead-in wire 11 while facing each other, and in this case, there is no directionality between front and back, and the upper metal terminal 1
If the connection to the printed circuit board is made on the side surface of the lower metal terminal 13b, the installation area on the printed circuit board can be reduced by 4 mm, and the mounting on the printed circuit board can be made more flexible.

In the past, various attempts have been made to make solid electrolytic capacitors rectangular in order to enable automatic alignment and automatic supply, but these use metal caps and It was extremely difficult to manufacture chip-type products.

On the other hand, according to the manufacturing method of the present invention, the capacitor element 10
The metal terminal turtle 3 is connected to the protruding lead-in wire 11 by welding using the raised resin part 12 at the base of the protruding lead-in wire 11 for positioning, compared to the case using the metal cap described above. The work is easy.

Furthermore, since there is no resin dripping, it is possible to obtain a product with high dimensional accuracy, and the metal terminal 13 can be connected close to the capacitor element, which is very effective in reducing the size. .

Further, if a magnetizable metal such as iron or nickel is used for the metal terminal 13, it becomes extremely easy to determine the polarity.

As described above, the manufacturing method of the present invention has extremely high industrial utility value in that it can easily produce a rectangular face bonding type group electrolytic capacitor with high dimensional accuracy that can be automatically aligned and automatically supplied. be.

[Brief explanation of the drawings] Figure 1 is a perspective view of a conventional solid electrolytic capacitor;
The figure is a diagram showing a manufacturing process in a method for manufacturing a solid electrolytic capacitor according to an embodiment of the present invention, and FIGS. Plan view and sectional view, 4th
Figures a, b, and c are respectively a perspective view, a plan view, and a sectional view showing another example, and Figures 5a, b, and c are a perspective view, a plan view, and a sectional view, respectively, showing another example. 10...Capacitor element, 11...Protruding lead-in wire, 12.
.....raised portion, 13.....metal terminal, 14,
15...Resin. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] 1 After forming a capacitor element by sequentially laminating a semiconductor layer, a cathode layer, and a cathode conductive layer on a dielectric oxide film on the surface of an anode body made of a valve metal, a protrusion extending from the anode body of the capacitor element is formed. A resin is applied to the base of the lead-in wire and cured to form a raised part of the resin, and then a metal terminal that will become an anode is brought into contact with the raised part of the resin, and the metal terminal is attached to the base of the protruding lead-in wire. A method for manufacturing a solid electrolytic capacitor, comprising: connecting the capacitor element to the metal terminal, and then covering the capacitor element with a resin between the capacitor element and the metal terminal and between the ends of the capacitor element other than the cathode end.