JPS6211217A - Electrolytic 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 small and flat electrolytic capacitor that can be mounted on a printed circuit board or the like.

[Conventional technology]

Electrolytic capacitors generally have a structure in which both sides of aluminum foil are roughened by etching, the foil is wound with a separator impregnated with electrolyte, the foil is inserted into a cylindrical case, and the lead wire is pulled out and sealed. It is true. Also known is an electrolytic capacitor which is wound into a cylindrical shape and then crushed into a flat shape so that the cross section becomes approximately elliptical.

[Problem that the invention seeks to solve]

It is desired that electronic components mounted on a printed circuit board occupy a small space, and recently there is also a demand for a structure that allows automatic assembly.

However, as mentioned above, conventional electrolytic capacitors are constructed by stacking and winding aluminum foil and a separator impregnated with electrolyte, so the cross section is circular or oval, and they occupy a relatively large amount of space. It took up a lot of space and had a shape that made it difficult to assemble automatically. Furthermore, since it involves a winding process, it has the disadvantage that mass production is not easy.

SUMMARY OF THE INVENTION An object of the present invention is to improve the above-mentioned conventional drawbacks and to provide a small electrolytic capacitor that is extremely thin and easy to handle.

[Means for solving problems]

The electrolytic capacitor and electrolytic capacitor of the present invention will be described with reference to FIG. 1. The metal foil 1 for an anode and the metal foil 1 for a cathode each have an inner surface roughened by etching or the like and lead terminals 5 and 6 provided on the outer surface. Separator 3 impregnated with electrolyte between foil 2
are interposed, a sealing layer 4 is provided around their periphery, and the sealing layer 4 is used to adhere and seal each other, and an insulating fiber-reinforced thermosetting resin layer for reinforcement is coated on the outer periphery. 7 is a pipe for venting the gas inside, and after venting the gas, the tip is crushed and sealed.

[Effect]

By providing the sealing layer 4 around the separator 3,
When the electrolyte is placed in the center, it will not leak to the outside,
Assembling becomes easy, and mutual adhesion can be performed at the periphery. Furthermore, since the plate-shaped metal foils 1 and 2 for the anode and cathode are joined with the separator 3 interposed therebetween, an extremely thin electrolytic capacitor can be formed. By covering the outer periphery with an insulating fiber-reinforced thermosetting resin layer, sufficient strength can be obtained without increasing the thickness of the insulating layer. .2 can be insulated from other parts, and an extremely thin electrolytic capacitor can be made strong enough to be easily handled.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a partially cutaway perspective view of an embodiment of the present invention, and FIG. 2 is a sectional view thereof. The inner surfaces of the plate-shaped anode metal foil 1 and cathode metal foil 2 are roughened by etching or the like, and lead terminals 5 and 6 are connected to the outer surfaces. A separator 3 impregnated with an electrolyte is interposed between these metal foils 1 and 2 for the anode and cathode, a sealing layer 4 is provided around them, and a sealing layer 4 is provided in contact with a part of the metal foil 2 for the cathode. Place the pipe 7 and place the anode metal foil 1. Separator 3. The cathode metal foils 2 are stacked and pressed together to be bonded and sealed by the sealing layer 4,
The internal gas is released through the pipe 7, and then the tip of the pipe 7 is crushed and sealed. and,
The outer periphery is coated with an insulating fiber-reinforced thermosetting resin layer 8.

Since the metal foil 1.2 for the anode and cathode is used as a plate, it is also possible to use metals such as tantalum (T a ) and titanium (Ti) in addition to aluminum (Al). be. Further, the surface roughening treatment may be performed only on one side, and the anodizing treatment on the anode metal foil 1 may be performed only on one side. As a method of roughening only one surface, for example, a roughening prevention film may be provided on the other surface and the surface roughening treatment may be performed by etching or the like. Similarly, for anodic oxidation, it is sufficient to provide an anti-oxidation film on the other surface.

The separator 3 is the same size or slightly larger than the metal foils 1.2 for the anode and cathode so that the metal foils 1.2 for the anode and cathode are not in contact with each other. 3 - can be constructed of the same materials as used in conventional electrolytic capacitors.

Further, the sealing layer 4 provided on the periphery can be made of, for example, an anaerobic curing resin, and when an electrolytic solution is placed on the center after being provided on the periphery of the separator 3, the electrolytic solution forms the sealing layer. 4
Therefore, when the metal foils 1.2 for the anode and cathode are stacked with the separator 3 interposed and pressure is applied, the surfaces of the sealing layer 4 in contact with each other are blocked from air. , will be cured, thereby adhering them together and creating a seal.

Further, the pipe 7 is arranged so as to be in contact with the cathode metal foil 2,
The internal gas is released and then the tip is crushed, and its thickness is selected so that the distance between the cathode metal foil 2 and the separator 3 is within a predetermined value. It is preferable to install this pipe 7 in a position where the gas generated during the aging process can be easily released, and it is also preferable that this pipe 7 serve as an explosion-proof valve when the internal pressure increases when the capacitor is used. can.

Further, the fibers in the reinforcing insulating fiber-reinforced thermosetting resin layer 8 can be made of various organic or inorganic fibers, such as paper, cloth, pulp, cotton, etc. By adding such reinforcing fibers to the resin layer, its strength can be significantly increased, which is very effective in forming thin electrolytic capacitors. Further, as the thermosetting resin, a sealing resin can be used. For example, kraft paper is impregnated with a sealing resin other than anaerobic curing,
The resin layer 8 can also be formed by pasting it on the outside of the metal foils 1.2 for the anode and the cathode, adhering the periphery thereof, and curing it.

To explain a specific example of the above-mentioned electrolytic capacitor, the metal foils 1 and 2 for the anode and cathode have a thickness of 0.07 m.
m, using aluminum foil with width IQmm and length 15mm,
The aluminum foil for the anode was subjected to a surface roughening treatment, and the aluminum foil for the anode was further subjected to an anodizing treatment, and a separator 3 was prepared with dimensions of 10.5 mm in width and 15.5 mm in length, which were slightly larger than the aluminum foils for the anode and cathode. The size of the separator material used is normal for electrolytic capacitors, and the sealing layer 4 is made of an anaerobic hardening resin made of polyester resin, dimethylaniline, cobalt naphthenate, and methyl ethyl ketone peroxide. As the cured resin layer 8, a solution of paraffin wax in styrene monomer is added to the sealing resin to remove anaerobic curing properties.
A single layer of kraft paper for electrolytic capacitors having a thickness of 0.08 mm and having good resin impregnation properties was impregnated with this resin as reinforcing fibers. If further strength of the resin N8 is required, long fibers (strong cloth) can be used as reinforcing fibers, or they can be constructed by stacking them in multiple layers.

Also, the pipe 7 has an outer diameter of 0.3 mm and a wall thickness of 0.05 mm.
The aluminum pipe was used.

During assembly, an anaerobic curable resin is applied as the sealing layer 4 to the aluminum foil for the anode and the cathode and the periphery of the separator, and after it is partially cured, the separator is crimped onto the aluminum foil for the anode. , by dripping electrolyte into the center of the separator and placing an aluminum pipe on top of it,
An aluminum foil for the cathode is crimped from above, the anaerobic curing resin is cured by blocking air, and kraft paper is impregnated with the resin and adhered to the outside of the aluminum foil for the anode and cathode. The resin was cured so as to surround the entire area. Then, during or near the end of the aging process, the tip of the aluminum pipe was crushed and sealed.

The completed electrolytic capacitor is approximately 1mm thick and 11mm wide.
, 15mm in length, working voltage 6.3V, capacity 10
It became μF. This electrolytic capacitor was subjected to a hot water resistance test at 90° C. for 5 minutes, but no abnormality was found in any part. In addition, if no reinforcing fibers are added to the outer resin layer 8, it will have an extremely thin shape with a thickness of about 1 mm or less.
Although it was easily bent and required careful handling, by covering it with a resin layer 8 containing reinforcing fibers,
Even though the thickness of the resin layer 8 is 9.3 mm or less,
It was sufficiently reinforced, easy to handle, and able to withstand the internal pressure of electrolytic capacitors.

FIG. 3 is an explanatory diagram of the manufacturing process of the electrolytic capacitor of the above-described embodiment, and the same reference numerals as in FIGS. 1 and 2 indicate the same parts. A strip-shaped anode metal foil l, one surface of which has been roughened by etching or the like and lead-out terminals 5 connected at predetermined intervals to the other surface, is coated with a resin-impregnated layer of kraft paper impregnated with a coating resin. 8a, separate separators 3 are placed on the anode metal foil 1, and then the pipe 7a is placed on top of the anode metal foil 1.
The metal foil 2 for cathode to which the lead terminal 6 is connected is placed on top of the metal foil 2 and crimped. In that case, a sealing layer 4 is formed between each, and the separator 3 is impregnated with an electrolytic solution.

After being mutually bonded and sealed by this sealing layer 4,
By placing a band-shaped resin-impregnated layer 8b similar to the lower resin-impregnated layer 8a, adhering the periphery so as to be surrounded by the lower resin-impregnated layer 8a, and curing the coating resin,
By forming the insulating fiber-reinforced thermosetting resin layer 8, aging treatment, and sealing the tip of the pipe 7, a plurality of electrolytic capacitors are manufactured at the same time. Then, by cutting at the cutting section, it is separated into individual electrolytic capacitors. Note that between the anode metal foil 1 and the anode metal foil 2 cut at the cutting part, the resin of the sealing layer 4 is impregnated into the separator 3 and hardened, so that the anode metal foil 1 and the cathode metal foil 2 are separated. There is no contact between the anode metal foil 1 and the cut anode metal foil 1.
Although the end portion of the cut portion is hardly exposed, if necessary, an insulating resin may be applied to the cut portion. In addition, if the anode metal foil 1 and the cathode metal foil 2 are reversed, even if a part of the cathode metal foil 2 is exposed at the cut part, the cathode metal foil 2 side is generally grounded, so the insulation can be improved. The problem will disappear.

It is preferable to form this separation section in advance with multiple holes or the like in the anode metal foil 1 to facilitate separation, and it is also possible to separate the sections individually during automatic assembly. becomes.

FIGS. 4(a) and 4(b) are other explanatory diagrams of the manufacturing process of the electrolytic capacitor of the above-described embodiment, and the same reference numerals as in FIG. 3 indicate the same parts. The resin-impregnated layer 8a, the anode metal foil 1 to which the extraction terminal 5 is connected, the separator 3, and the cathode metal foil 2 to which the extraction terminal 6 is connected are each in the form of a band, and the separator 3 is coated with the sealing layer 4 in advance. , and are impregnated with an electrolytic solution, and the pipe 7 is placed thereon, and as shown in FIG. 4(a), they are overlapped and crimped together. As a result, they are bonded to each other, and the resin-impregnated layers 3a and 3b are hardened, aged, and the tip of the pipe 7 is sealed. Thereby, a plurality of consecutive electrolytic capacitors are manufactured simultaneously.

Next, as shown in FIG. 4(b), the lower resin impregnated layer 8
Make a cut for separation leaving point a. Thereby,
Since the ends of the anode metal foil 1 and the cathode metal foil 2 are exposed, a resin layer 10 is formed by applying a sealing resin or the like. In this case, the electrolytic capacitors are connected to each other by the resin-impregnated layer 8a, and the resin-impregnated layer 8a can be easily cut, so that it can be applied to an automatic assembly line.

In the above-mentioned embodiment, the anode metal foil 1 was roughened and anodized, and the cathode metal foil 2 was simply roughened. It is also possible to anodize the capacitor and make it into an anode metal foil. In this case, the capacitance becomes smaller and a non-polar electrolytic capacitor is formed. Therefore, in the present invention, "anode metal foil" and "cathode metal foil" are component names for distinguishing metal foils arranged opposite to each other.

〔Effect of the invention〕

As explained above, in the present invention, plate-shaped metal foils 1 and 2 for an anode and a cathode are pressed together with a separator 3 impregnated with an electrolytic solution interposed therebetween, and a resin layer 8 reinforced with reinforcing fibers is formed. Since it is coated, it has an extremely thin and flat shape and has good heat dissipation characteristics, so it is less affected by heat caused by soldering to a printed circuit board, making it easier to mount it on a printed circuit board. Also, metal foil for anode and cathode19.
2 has the advantage that only the facing surface needs to be roughened by etching or the like, so the depth of the roughening treatment can be increased, so there is a large degree of freedom in increasing the capacity. Since it has a simple configuration, it has the advantage of being easy to manufacture and suitable for mass production.

Furthermore, since the lead-out terminals 5 and 6 are connected to surfaces that are not roughened and anodized on the outer surface of the plate-shaped metal foils 1 and 2, the connection is easy and electrical and Good mechanical connection can be maintained. In addition, the lead terminals 5.6 are connected to the outside that does not come into contact with the electrolyte, and furthermore, the parts of the anode metal foil 1 other than the anodized part do not come into contact with the electrolyte, which reduces the aging time. It has the advantage of reducing leakage current, thereby improving electrical characteristics.

In addition, since a sealing layer 4 is provided on the periphery to bond and seal each other, the sealing layer 4 serves to limit diffusion and prevent leakage during injection of electrolyte, making assembly easy. There are advantages.

In addition, by coating with the insulating fiber-reinforced thermosetting resin layer 8, the outside of the metal foils 1.2 for the anode and cathode are insulated, and the strength is several times greater than when the metal foils 1.2 are coated with resin alone. This makes it possible to construct an ultra-thin electrolytic capacitor that is easy to handle.
There is an advantage that automatic assembly is also possible.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway perspective view of an embodiment of the present invention, FIG. 2 is a sectional view, and FIGS. 3 and 4 (a) and (b) are explanatory views of the manufacturing process of an electrolytic capacitor. 1 is a metal foil for the anode, 2 is a metal foil for the cathode, 3 is a separator, 4 is a sealing layer, 5 and 6 are lead terminals, 7 is a pipe for degassing, 8 is an insulating fiber reinforced thermoset for reinforcement It is a plastic layer.

Claims (1)

[Claims] A separator (3) impregnated with an electrolytic solution is interposed between a plate-shaped metal foil for an anode (1) and a metal foil for a cathode (2), each having a roughened inner surface and a lead-out terminal connected to the outer surface. ,
An electrolytic capacitor characterized in that they are bonded and sealed together by a sealing layer (4) provided on their periphery, and the outer periphery is covered with an insulating fiber-reinforced thermosetting resin layer (8) for reinforcement. .