JPS5879715A - Chip type electrolytic condenser and method of producing same - 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 The present invention relates to a chip electrolytic capacitor, and more particularly to an electrode extraction structure of a chip electrolytic capacitor and a method for manufacturing the same.

In recent years, with remarkable progress in mounting technology for electronic components, demand has increased for smaller electrolytic capacitors as electronic components. What type of electrolytic capacitors have been provided to meet such demands? As shown in FIG. 1, the O structure includes an anode body 1 formed by planting an anode lead 6 having a valve action on a metal powder having a valve action such as tantalum or aluminum, and molding the anode lead 6 into a desired shape.
A dielectric oxide film 2, a solid electrolyte layer 3, and a conductive counter electrode 4 are sequentially formed thereon to form a capacitor element. Thereafter, the anode lead 6 and the anode external terminal 8 are directly connected by means such as resistance welding.

On the other hand, the cathode external terminal is connected to a 7-wire conductive counter electrode 4 via a conductive adhesive 5. After that, the anode external terminal 8 and the cathode external terminal 7 are left ('n, with some t- left,
An insulating member 9 made of resin or the like is provided.

Such a conventional structure not only has the disadvantage that the external terminal extraction area is only on one side and is limited to one direction when mounting P1. , reduce the size of the anode body l of the capacitor element, or connect the root part 6a of the anode lead to the anode external terminal 8.
The only room for improvement was to change the distance to the connecting portion 88 or the structure of the cathode external terminal 7. However, making the insulating member 91" thinner has disadvantages such as deterioration of moisture resistance, exposure of the capacitor element, and inability to maintain the role of mechanical protection. Furthermore, making the capacitor element smaller is also disadvantageous.

The ratio of anodizing voltage to rated voltage must be small.
However, it also has the disadvantage of inferior capacitor reliability. Therefore, in order to reduce the size of electrolytic capacitors, the only option left is to shorten the distance from the root portion 6m of the anode lead to the connection portion 8a with the anode external terminal 8 and the distance between the cathode terminal 7 and the capacitor element.

As an improved version of this structure, there is one in which cap-shaped metal terminals are used as the external terminals of the anode and cathode, as shown in FIG.

After forming the capacitor element tube in the same manner as described above, the anode lead wire and the cap-shaped anode metal terminal 10 are bath-bonded, and the capacitor element and the cap-shaped other metal terminal 11 are each bonded with a conductive adhesive 5. They are connected to each other and covered with an insulating member 9 made of resin or the like.

However, since the capacitor with this improved structure also uses welding means to connect the cap-shaped anode metal terminal lO and the anode lead 6, the welding point 10m and the root part 6a of the anode lead
If the distance is short, the dielectric oxide film 2 will be destroyed by thermal energy during welding. Therefore, in order to prevent destruction of the dielectric oxide film, it is necessary to increase the distance between the welding point lOa and the root portion 6a of the anode lead. Further, on the cathode side as well, a certain degree of thickness of the conductive adhesive material 5 is required in order to increase the adhesive strength between the cap-shaped cathode metal terminal 11 and the capacitor.

Another important point is that the process of connecting the anode and cathode character terminals must be carried out individually, requiring a large number of man-hours. Moreover, the screw between the two is t″LsLs
It has the drawback that dimensional accuracy is a national problem due to the occurrence of positional defects and the so-called flatness and torturous properties. What! A pole extraction means is desired.

An object of the present invention is to provide a chip-type electrolytic capacitor and a method for manufacturing the same that meet such requirements.

According to the present invention, a dielectric oxide film, a solid electrolyte, and a conductive counter electrode are provided on the anode body, which is formed by planting an anode lead T-shaped in a metal powder having a valve action and molding it into a desired shape. In a capacitor element formed by sequentially forming the anode lead, the capacitor electron is covered with an insulating member so as to expose the tip of the anode lead and a part of the tetraelectric counter electrode, and the capacitor electron is covered with an insulating member on the knitted part and the rim member. A solid electrolytic capacitor and a method for manufacturing the same are obtained, which are characterized in that the solid electrolytic capacitor is connected to a conductive layer formed by any one of electroless plating, ion blating, vapor deposition, sputtering, and coating of a conductive resin. .

DESCRIPTION OF THE PREFERRED EMBODIMENTS The chip W electrolytic capacitor of the present invention and its manufacturing method will be described in detail below with reference to the drawings.

Figure 3 shows an embodiment of the present invention, and 1 in Figure 1 is an anode body made by pressing metal powder such as tantalum, niobium, aluminum, etc., which has a valve action, and sintering it.
It is also possible to omit the sintering operation. Reference numeral 6 denotes an anode lead drawn out from the body l, and a metal wire or plate having a valve action is planted on the anode body l as a cathode lead. a dielectric oxide film formed on the surface of the 2-mineral anode body 1;
is an rLe solid electrolyte layer formed on this oxide film 2.

4 is a conductive counter electrode that covers most of the anode body l. The conductive counter electrode 4 is generally composed of a graphite layer and a mackerel paste layer.

Other conductive materials such as copper may also be constructed by means of plasma spraying, ion blating, etc. 9
are the tip 6b of the anode lead 6 and the conductive counter electrode 4.
The insulating member is made of a material such as epoxy resin, silicone resin, glass, or ceramic, and is coated so that a portion 4b of the insulating member is exposed.

Coating and transfer molding as a means of price reversal.

For products with high dimensional accuracy, such as casting and thermal spraying, we offer transfer swords.

A method such as casting is preferable. 12 is a conductive member for an anode coated on the insulating member 9 so as to have an electrical connection with the tip 6b of the anode lead 6, and 13 is a conductive opposing member on the insulating member 9. A cathode conductor 'f/ is a member which is deposited so as to be electrically connected to a portion 4b of the electrode 4.

The anode/cathode conductive members 12 and 13 are made of solderable metal layers such as metals such as copper, silver and nickel, and alloys such as copper-2 and tal. may be the same metal material or may be different materials.

Further, it is preferable to coat the anode and cathode conductive members 12 and 13 with solder to prevent soldering due to oxidation of the electrode members.

Next, an example of the method of manufacturing a tantalum solid electrolytic capacitor according to the present invention is shown in Fig. 4 (a) ν (b) = (c)
This will be explained with reference to t-.

First, as in the well-known technique, an anode lead 6 made of tantalum wire is planted, high-purity tantalum powder is pressure-molded into a desired shape, and then vacuum sintered to form an anode body 1. Next, a depleted oxide layer jl[2t- is formed on the surface of the anode body l by electrochemical means. Next, it is immersed in a manganese nitrate bath and thermally decomposed to form a solid electrolyte layer 3 of manganese dioxide on the dielectric oxide film 2.

Next, a conductive counter electrode 4t consisting of a graphite layer and a silver paste layer is formed to complete the capacitor element (FIG. 4(a)).

Next, as shown in FIG. 4(b), an insulating member 9 is coated with epoxy resin over the entire capacitor element by transfer molding, with the tip portion 6b of the anode lead and the portion 4b of the conductive counter electrode 4 left in a state of being free. establish.

After that, walnut powder is sprayed onto the capacitor element provided with the insulating member 9 to remove the oxide film formed on the anode lead 6 and the paris generated during molding, and to roughen the surface of the insulating member 9. .

Next, as shown in FIG. 4(C), after masking the separated parts of the anode and cathode conductive members 12 and 13t, the tip 6b of the electrode and a part of the conductive counter electrode are masked. Copper is formed on the insulating member 9 by electroless plating so as to be electrically connected to the insulating member 4b. As an electroless plating method, first, as a pretreatment, it was immersed in dimethylformadochromic acid for several minutes to roughen the surface and clean it. After that, it is immersed in an electroless plating catalyst solution and converted to oxalate.) After IJum treatment, sulfuric acid steel, E
DT (formaldehyde, etc.)'Hex12 Conductive members 12 and 13t for anode and cathode were formed with a copper layer for electrical connection. After that, in order to prevent copper from oxidizing, conductive members 12 and 1 for cathode
3 was covered with a solder layer.

As described above, in the chip type electrolytic capacitor of the present invention, the 'wt pole terminal of the conventional configuration is unnecessary, and the length and width are reduced.

Not only can it be made smaller in terms of height.

The deterioration of capacitor characteristics during the welding process is significantly improved without requiring the conventional welding process.

Furthermore, since the process of connecting the X-electrode terminals can be shifted from individual processing to batch processing, there is an advantage that mass production can be carried out.

1 Regarding the present invention, only the electroless plating method and the plasma spraying method of copper are described as examples.

For soldering such as gold, metals that can be used may be used, and vapor layer method,
Of course, sputtering, ion blasting, and plasma spraying can also be used.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views of a conventional chip electrolytic reduction capacitor, and FIG. 3 is a cross-sectional view of a chip electrolytic capacitor according to an embodiment of the present invention. FIG. 3 is a cross-sectional view for explaining the manufacturing process. DESCRIPTION OF SYMBOLS 1... Anode body, 2... Dielectric oxide film, 3... Solid electrolyte layer, 4... Conductive counter electrode, 5...・・Conductive adhesive, 4b・・・・
・・Conductive counter electrode〇part (exposed part), 6・・・・・・
Anode lead, 7...-external terminal 6a...
... Root of the anode lead, 6b... Tip of the anode lead, 8... Anode external terminal, 9...
- Insulating member, 8a...Connection part between the anode lead and the #III external terminal. 10... Cap-shaped anode metal terminal, 11...
...Kiya, fake money I! 4 bites, 12-...
Conductive material for anode. 13... Conductive member for cathode. Figure 7, Figure 2, Figure 5, Figure 3 (a).
(b) Figure 4 (C)

Claims (7)

[Claims] (1) A dielectric oxide film is formed, a bid body electrolyte layer and a conductive counter electrode are formed on the anode body, which is made by planting a positive electrode having a valve effect on a metal powder having a valve effect and forming it into a desired shape. In the capacitor element, the capacitor element is covered with an insulating material except for the tip of the anode lead of the capacitor element and a part of the conductive counter electrode, and the tip of the anode lead is sequentially formed on the electrode. A chip type electrolytic capacitor characterized in that a part of the conductive counter electrode is connected to a conductive layer provided on the insulating member. (2) A step of planting an anode lead T having a valve action on a metal powder having a yP action and reducing it to a desired shape to form an anode body, and forming a galvanic oxide film and a solid electrolyte on the anode body. 11 steps of forming a layer and a conductive counter electrode; a step of covering the anode lead tip and a part of the conductive counter electrode with an electrically insulating material; [Conductor 11 connected to part of the pole
A method for manufacturing a chip type electrolytic capacitor, comprising a step of forming 1rm on the insulating member and gold. (3) The method for manufacturing a chip-type electrolytic capacitor according to claim 2, wherein the step of forming the conductive layer provided on the insulating member is electroless plating. (4) Claims FtI characterized in that the step of forming the conductive layer provided on the insulating member is vapor deposition. 2. The method for manufacturing a chip-type electrolytic capacitor according to item 2. (5) The method for manufacturing a chip-type electrolytic capacitor according to claim 2, wherein the step of forming the conductive layer provided on the insulating member is sputtering. (6) The method for manufacturing a chip-type electrolytic capacitor according to claim 1g2, characterized in that the step of forming the conductive layer provided on the insulating member is ion blating. (7) The method for manufacturing a chip-type dielectric capacitor according to claim 2, wherein the step of forming the conductive layer provided on the insulating member is performed by coating a tetraelectric resin.