JPH0417318A - Manufacture of solid electrolytic capacitor - Google Patents

Abstract

PURPOSE:To obtain a manufacturing method of a capacitor which is manufactured with good efficiency and at a low cost and whose performance is excellent by a method wherein the tip of a long tapelike valve-metal etched foil is connected perpendicularly to the length direction of a metal sheet or a metal wire, the foil is cut to a prescribed length, cut foils are arranged in parallel and an element for capacitor use is manufactured. CONSTITUTION:The tip of a long tapelike valve-metal etched foil 2 is connected perpendicularly to the length direction of a metal sheet 5 or a metal wire; after that, the foil is cut to a prescribed length, cut foils are arranged in parallel; an element for solid electrolytic capacitor use is manufactured. Then, a dielectric oxide film layer is laminated and formed on the surface of respective valve-metal etched foils 2' arranged in parallel; a semiconductor layer is laminated and formed on a prescribed position on the surface; a dielectric layer is laminated and formed additionally on the surface sequentially; after that, the metal sheet 5 or the metal wire is removed or it is cut and separated in a part where the semiconductor layer has not been formed; and the foils are used as elements for solid electrolytic capacitor use. Alternatively, a long tapelike valve metal etched foil 2 is prepared in such a way that a dielectric oxide film layer has been formed on the surface; and a semiconductor layer and a conductor layer are laminated on the surface.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for manufacturing a solid electrolytic capacitor that has high production efficiency, enables cost reduction, and has excellent characteristics.

[Conventional technology]

Conventionally, when manufacturing a solid electrolytic capacitor, first, unnecessary parts are removed from a plate-shaped valve metal etched foil by means such as punching, and then a comb-shaped structure in which a plurality of rectangular parts are arranged in parallel and connected at one end, Or a solid electrolytic capacitor element (hereinafter referred to as a capacitor element) in which a plurality of rectangular parts are connected in a skewer shape in the length direction, and one end of the plurality of skewer-shaped parts are connected in parallel. or used. After sequentially laminating a dielectric oxide film layer, a semiconductor layer, and a conductive layer on the rectangular parts of these capacitor elements, the comb-shaped ones are cut and separated into rectangular parts, and the comb-shaped ones are made by cutting and separating the rectangular parts. A solid electrolytic capacitor is manufactured by using a solid electrolytic capacitor element (hereinafter referred to as a capacitor element) that can be cut and separated and bent to overlap the rectangular parts (for example, the
-10564, Japanese Patent Application Laid-Open No. 59-61116)
.

[Problem to be solved by the invention]

However, these capacitor elements are manufactured by punching valve metal etched foil, so if the thickness of the foil to be punched is thin, the punching die and the foil to be punched will stick together, making operation difficult. Valve metal etched foil with a

At this time, the thicker the capacitor, the larger the volume, the longer the depth of the semiconductor layer of the solid electrolytic capacitor (hereinafter referred to as a capacitor) made using this capacitor, the higher the resistance, and the worse the high frequency performance.

This tendency becomes even more remarkable when the area of the rectangular portions is small or when the distance between the rectangular portions is small.

In addition to the above-mentioned punching, in order to produce capacitor elements,
A method of forming a valve metal etched foil in a predetermined shape by photo-etching may also be considered, but this would not only increase the cost but also require the above-mentioned valve metal processing.

This method cannot be used because the surface of the etched foil is not as smooth as ordinary metal, and the interface between the photoetched portion and the mask is non-uniform.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for manufacturing a capacitor that is efficiently produced at low cost and has excellent performance.

[Means to solve the problem]

In order to achieve the above object, the method for manufacturing a capacitor according to the present invention involves connecting a long tape-shaped valve metal etching foil at a right angle to the length direction of a metal plate or metal wire, and then A capacitor element is fabricated by cutting to length and arranging them in parallel. Next, a dielectric oxide film layer is formed on the surface of each of the valve metal etching foils arranged in parallel, a semiconductor layer is added at a predetermined position on the upper surface, and After sequentially laminating conductive layers on the upper surface thereof, they are removed from the metal plate or metal wire, or separated by cutting at a portion where no semiconductor layer is formed, and used as a capacitor element.

Alternatively, as the long tape-shaped valve metal etching foil, a long tape valve metal etching foil having a dielectric oxide film layer formed on the surface may be used.

Further, it is also possible to arrange the long tape-shaped valve metal etching foils in parallel and connect the tips of a plurality of them to the metal plate or metal wire at the same time.

[For production]

Since the method of the present invention has the above-mentioned structure, the thickness of the valve metal etching foil is thin (also, the comb-shaped capacitor element connected at one end by a metal plate or metal wire can be efficiently and inexpensively used). can get.

〔Example〕

As the long tape-shaped valve metal etching foil used in the present invention, any etching foil of a metal having valve action such as aluminum, tantalum, niobium, titanium, or an alloy having these as a substrate can be used. As a method for etching the valve metal foil, a known method such as electrochemical etching may be used.

The long tape-shaped valve metal etching foil may have a dielectric oxide film layer formed on its surface in advance.

Furthermore, the metal plate or metal wire that connects the tape-shaped valve metal etching foils in parallel has the function and strength to connect the valve metal etching foils, and even if the valve metal etching foils are connected, the metal plates or metal wires have the strength and function to connect the valve metal etching foils. If not, there are no particular limitations, and examples include plates or wires made of stainless steel, copper, iron, aluminum, nickel, etc.

Its length is determined by the width of the tape-shaped valve metal etching foil, the number of connected pieces, and the spacing. The thickness or diameter of the metal plate or metal wire varies depending on the number of valve metal etching foils to be connected, but for plates the thickness is usually 0.1mm or more and for several mm or less, and for wires the diameter is 1m
A length of 1 m or more and a few mm or less is used.

The dielectric oxide film layer (hereinafter referred to as an oxide film layer or a chemically formed film) may be an oxide film layer of the valve metal itself or another dielectric film provided on the valve metal etching foil. It may be an oxide layer of the valve metal itself, or preferably a layer consisting of an oxide of the valve metal itself.

In either case, a conventionally known method can be used to provide the oxide layer.

For example, when using aluminum foil, if the surface of the aluminum foil is electrochemically etched and further electrochemically treated in an aqueous solution of boric acid and ammonium borate, an oxide layer consisting of an alumina dielectric is formed on the aluminum foil. It is formed.

Although there are no particular restrictions on the composition or manufacturing method of the semiconductor layer used, in order to improve the performance of the capacitor, it is recommended that lead dioxide, or lead dioxide and lead sulfate be used as main components, as proposed by the present inventor. It is preferable to use a conventionally known chemical deposition method or electrochemical deposition method (Japanese Unexamined Patent Publication No. 6351321).

The conductive layer formed on the surface of the semiconductor layer is formed by a known method such as solidification of a conductive paste, plating, metal vapor deposition, or lamination of a heat-resistant conductive resin film.

Next, a capacitor element using the above-mentioned valve metal etching foil, metal plate, etc., and a method for manufacturing the capacitor element will be described using a case where a metal plate is used as a representative example.

1 and 2 show an example of an apparatus for carrying out the method of the present invention, in which reference numeral 1 denotes a supply of a long tape-shaped valve metal etching foil (hereinafter referred to as foil) 2 wound thereon. It's a roll.

The cylinder 2 is drawn out from the supply roll 1 by a guide roll 3 and sent out through a guide rail 4. When the end reaches the metal plate 5, the joining machine 6 descends and joins the foil 2 to the metal plate 5 electrically or mechanically. Examples of the joining method include caulking, soldering, joining using conductive paste, ultrasonic welding, dropper welding, and electron beam welding. Next, cut A-A with a cutter etc.
Cut the foil 2 in parts.

Next, the metal plate 5 is moved by a predetermined distance in the direction of the arrow 7 and the above operation is repeated. In this way, on one side of the metal plate 5,
A comb-shaped capacitor element is produced in which one ends of rectangular foils 2 are connected at predetermined intervals.

In the above explanation, the rectangular foils 2'' are connected one by one, but it is also possible to bend the supply roll 1 multiple times, feed out the foils 2, and connect multiple rectangular foils 2' to the metal plate at the same time. It can also increase efficiency.

In addition, after joining the foil 2 to the metal plate 5, the foil 2' was cut and bound into a rectangular foil 2', but it is also possible to first cut the foil 2' into a rectangular foil 2' and then join this to the metal plate 5. However, cutting and joining may be performed at the same time. When joining after cutting, the rectangular foil 2' is cut in a vacuum system, for example, in order to place the cut rectangular foil 2' at a predetermined position on the metal plate 5. ” may be used. For example, a method can be used in which a movable pipe connected to the end of a vacuum line is applied to a rectangular foil 2' to adsorb the foil, and then the foil is detached from the pipe by cutting off the vacuum line of the pipe with a switch, etc. I can give it to you.

The dimensions of the capacitor element described above can be freely adjusted by selecting the width of the foil 2 wound around the supply roll and the position of the cutting line A-A, and the gap between the foils bonded to the metal plate is It can be selected arbitrarily depending on the feed width.

Next, a method for manufacturing a capacitor from a capacitor element manufactured by the method of the present invention will be described.

A semiconductor layer is formed on a predetermined portion of a capacitor element in which a plurality of rectangular valve metal etching foils having a dielectric oxide film on the surface are connected. A semiconductor layer is formed.

In this case, it is important that the position where the semiconductor layer is formed be aligned in advance so that it does not connect to the metal plate in order to prevent electrical short-circuits. As for the type of semiconductor layer, are there any conventionally known ones that can be used? In particular, lead dioxide, which was proposed by the present inventors in JP-A No. 63-51621,
A semiconductor layer mainly composed of lead dioxide and lead sulfate is preferable because the produced capacitor has good high frequency characteristics.

The capacitor element formed up to the semiconductor layer is immersed in a conventionally known carbon paste and/or silver paste bath,
By pulling up, a conductor layer is formed on the semiconductor layer. Each of the valve metal etched foils is then removed from the metal plate, or the valve metal etched foils are cut at locations where no semiconductor layer is formed to produce individual capacitor elements. Furthermore, REET wires are attached to the valve metal etched foil portion where the semiconductor layer is not formed and to the portion where the conductor layer is formed. Finally, it can be made into a general-purpose capacitor product for various uses by, for example, resin molding, resin case, metal outer case, resin dipping, laminated film outer case, etc.

Example 1 Aluminum chemical stone (4
A supply roll wound with 0 μF/cm') was set in the device, the foil pulled out from this was pulled out with a kite roll, and the tip of the foil was passed through the kite rail to a length of 40 mm, mo, 5
It was made to protrude onto a stainless steel plate of mm. The foil was then electrically and mechanically joined using a spot welder (manufactured by Nippon Avionics Co., Ltd.) installed on the stainless steel plate, and the foil was then cut parallel to the longitudinal direction of the stainless steel plate at a distance of 5 mm from the side of the stainless steel plate. did. Next, the stainless steel plate was moved 4 a+m in the longitudinal direction, and the process of pulling out the foil again, connecting it to the stainless steel plate, and cutting it was repeated. In this way, on the side of the stainless steel plate, a length of 5 mm from the side and a width of 3 m is attached.
A comb-shaped capacitor element was prepared in which 100 pieces of rectangular foil of m diameter were lined up at an interval of 1 mm.

Next, a capacitor was manufactured by a known method using the manufactured capacitor element.

First, the rectangular foil side of the capacitor element was immersed in an aqueous solution of phosphoric acid and ammonium phosphate, leaving 0.51 mm from the side of the stainless steel plate, to reconstitute it. Next, the rectangular foil part was immersed in a mixed solution of 24 mol/Q aqueous solution of lead acetate trihydrate and 4 mol/C aqueous solution of ammonium persulfate, leaving a distance of 2111 m from the side of the stainless steel plate at 40°C.
25 wt% lead dioxide, 75 wt% lead sulfate
% was formed. Furthermore, after forming a conductor layer on the semiconductor layer and the conductor layer by sequentially immersing it in a carphone paste bath and a silver paste bath, all the foils were cut at a portion of 1.51 mm from the side surface of the stainless steel plate.

Next, two separately prepared copper plates (width 2 mm, length 5 + n
The parts (0.5 x 3 mm) of the fabricated foil where only the conductor layer and dielectric layer exist were placed on the foils (0.5 mm x 3 mm), the former was coated with silver paste, the latter was coated with stubs,
) A capacitor was fabricated by electrically and mechanically connecting them by welding and sealing them with resin. The characteristic values of the manufactured capacitor were measured and shown in Table 1.

Table 1 However, (1) is 120Hz, (2) is 100KHz, (
3) is the value at 10 V.

〔Effect of the invention〕

As explained above, in the method for manufacturing an element for an electrolytic capacitor according to the present invention, a long tape-shaped valve metal work/notching foil is sequentially fed out, connected to a metal plate or metal wire, and then cut, so that the foil is continuous. This method is extremely efficient compared to the conventional method, and since it is not manufactured by punching out large foils using a mold, the spacing between the foils can be kept extremely small, so the number of tubes in one element can be reduced. You can save more and reduce costs.

Furthermore, the solid electrolytic capacitor produced using this
It has advantages such as superior characteristics.

[Brief explanation of drawings]

1 and 2 are diagrams showing an example of an apparatus for carrying out the method of the present invention. FIG. 1 is a side view, and FIG. 2 is a side view of FIG.
■It is a line arrow view. 1... Supply roll, 2... Long tape-shaped valve metal etching foil 2'.
... Rectangular foil, 3 ... Guide roll, 4 ... Guide rail, 5 ... Metal plate, 6 ... Joining machine, 7 ...・Arrow. (foil)

Claims (3)

[Claims] (1) After connecting the tips of the long tape-shaped valve metal etching foil at right angles to the length direction of the metal plate or metal wire,
A solid electrolytic capacitor element is produced by cutting to a predetermined length and placing them in parallel, and then a dielectric oxide film layer,
After sequentially forming a semiconductor layer at a predetermined position on the upper surface and a conductor layer on the upper surface, it is removed from the metal plate or metal wire, or separated by cutting at a location where the semiconductor layer is not formed. and a method for manufacturing a solid electrolytic capacitor, characterized in that these are used as a solid electrolytic capacitor element. (2) The long tape-shaped valve metal etching foil is a long tape valve metal etching foil with a dielectric oxide film layer formed on the surface, and is sequentially applied to the surface of each valve metal etching foil arranged in parallel. 2. The method of manufacturing a solid electrolytic capacitor according to claim 1, wherein what is laminated is a semiconductor layer at a predetermined position and a conductor layer on the upper surface of the semiconductor layer. (3) The method for manufacturing a solid electrolytic capacitor according to claim 1 or 2, wherein the long tape-like valve metal etching foil is a plurality of long tape-like valve metal etching foils arranged in parallel.