JPS6359528B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a capacitor that improves the capacitor jacket.

Conventional electrolytic capacitors connect the lead leads to the anode and cathode electrode foils by crimping, etc.
A capacitor element 1 is formed by winding electrolytic paper, and then the capacitor element 1 is impregnated with an electrolyte, and a pre-formed rubber sealing body 2 is attached to the lead 3 of the capacitor element 1. was housed in a bottomed cylindrical case 4 made of aluminum or the like, the sealing body 2 was fitted into the opening of the case 4, and the opening of the case 4 was sealed by winding the opening, as shown in FIG.

However, sealing materials such as rubber are not suitable for long-term use.
Compression set and impact resilience decreased, packing sealing properties deteriorated, and ionic impurities in the rubber compound were leaked out, significantly affecting the life characteristics of electrolytic capacitors.

Furthermore, external shocks have an adverse effect on the leakage current of the capacitor element through the lead wire.

Therefore, if necessary, the rubber sealing body is filled with resin to fix the lead wires.

Capacitors that require such a liquid impregnation agent are generally enclosed in a case and use a rubber seal, so when inserting the case or seal,
Processing and usage errors are common, which impede productivity, and when the sealing body is inserted into the case and sealed, stress is applied to the capacitor element, leading to breakage of the lead connections, disconnection, or damage to the anodic oxide film. There were drawbacks such as damage.

The present invention eliminates the above-mentioned drawbacks and provides a method for manufacturing capacitors that is compact and extremely productive.

The capacitor of the present invention will be explained below based on the embodiments of the electrolytic capacitor shown in FIGS. 2 to 4.

That is, in the electrolytic capacitor of the present invention, the lead leads 13 are connected to the anode and cathode electrode foils by caulking or the like, and the capacitor element 11 shown in FIG. After fixing the lead 13 drawn out from the capacitor element 11 to the strip mount 15 as shown in FIG.
A curable liquid resin 16 whose viscosity ratio is adjusted in advance to 1.5 to 7 is placed near the base of the lead 13 of No. 1.
(For example, epoxy resin, urethane resin, polyester resin, butadiene resin, epoxy acrylate, urethane acrylate, etc.) is coated or injected into a lump to cover a part of the lead 13, and the resin 16 is cured to form two leads. 13 is fixed.

Then, the impregnating agent (electrolyte) is applied to the capacitor element 11.
Then, the lead 13 is impregnated with the lead 13 as shown in FIG.
The capacitor element 11 is dip-coated or coated in a resin having a low water vapor permeability and a high heat distortion temperature equivalent to the bulk resin 16 coated or injected into the lead 13, and is coated or injected into the resin to form a first exterior coating. 14, and then NBR (manufactured by Nippon Zeon)
The exterior 17 is made of a barrier material such as Nipol latex), polyvinylidene chloride (Kurevalon latex manufactured by Kureha Chemical Co., Ltd.), and polyvinyl alcohol, and the exterior 18 is made of a resin equivalent to the first exterior coating 14.
However, when selecting the lead fixing resin 16 and the first and third exterior resins, the lead 13 is sealed with a multilayer sandwich coating.
After treating the lead part with a silane coupling agent (X-12-413 manufactured by Shin-Etsu Chemical), urethane acrylate resin (viscosity ratio 3.5, 2700 CPS) is injected into the lead part, irradiated with ultraviolet rays, and cured and fixed. This is desirable. In addition, the second exterior resin cannot prevent the internal pressure from increasing when voltage is applied to the capacitor and the impregnating agent gasifies and evaporates if the first exterior resin is used alone, and the capacitance and loss cannot be prevented from increasing in the life test. Figure 5 shows the life test for a 10μF, 16WV.DC electrolytic capacitor (ambient temperature 85℃, applied voltage 16VDC)
It shows the △tanδ (%) - time characteristic of , where ~ is 45 when the heat distortion temperature is 45 without the second outer coating.
The product using epoxy acrylate at 105°C and 155°C is the product of the present invention, and the product is packaged in a conventional aluminum case.

If the viscosity ratio of the resin injected or applied to the lead is less than 1.5, the spacer paper of the capacitor case will be impregnated with the resin, making it impossible to impregnate the impregnating agent, and if it exceeds 7.0, the resin and the lead will not be compatible and the adhesion will not be complete. I can't. Therefore, the viscosity ratio is
A value over 1.5 and under 7.0 is suitable. In addition, the resin applied or injected onto the leads should be applied or injected so as not to come into contact with the capacitor element on the lead as much as possible, so that the impregnating agent can easily impregnate the capacitor element. Since the wire is constructed by connecting a flat aluminum terminal and a lead rod, the connecting portion may be disconnected, so it is recommended to cover the connecting portion in order to reinforce the connecting portion.

As described above, in the capacitor of the present invention, resin is applied or injected to the lead portion of the capacitor element, a resin lump is formed on the lead, the capacitor element is impregnated with an impregnating agent, and the resin exterior is applied.
It has high airtightness, no leakage of impregnating agent, part of the resin mass and resin exterior has three layers, and the overlapping part of the three layers has an explosion-proof effect, and the lead connection part can be reinforced. In addition, compared to conventional case encapsulation or resin exterior, there is less resin on the leads due to poor solder connections, maintaining uniform quality, reducing the number of man-hours required for the exterior of the capacitor element, and reducing the number of parts. It has many effects such as reducing the amount of carbon dioxide and is industrially useful.

[Brief explanation of drawings]

Figure 1 is a sectional view of a conventional electrolytic capacitor, Figure 2 is a cross-sectional view of a conventional electrolytic capacitor.
The figure is a plan view of an electrolytic capacitor element, Figure 3 is a plan view of a taped capacitor element and lead fixing resin injected or applied during the manufacturing process of the product of the present invention, and Figure 4 is a cross section of the electrolytic capacitor of the present invention. Figure 5 is a Δtanδ (%)-time characteristic diagram of the life test. 11: Capacitor element, 13: Output lead, 1
4: first exterior coating, 15: strip-shaped mount, 16: curable liquid resin, 17: second exterior coating, 18: third exterior coating.

Claims (1)

[Claims] 1. In a capacitor formed by winding or laminating a separator between opposing electrodes, at least two lead wires drawn out from a capacitor element are injected or coated with a curable liquid resin to form a lump, and the lead wires are After covering and fixing the capacitor element, the capacitor element is impregnated with an impregnating material, and the capacitor element is coated with a first outer covering of a resin having a low water vapor permeability and a high heat distortion temperature, and then vinylidene chloride having a low gas permeability, A method for manufacturing a capacitor, comprising applying a second outer covering with an emulsion of NBR (nitrile butadiene rubber) or an aqueous polyvinyl alcohol solution, and further applying a third outer covering with a curable resin to form a multilayer outer covering.