JP7196846B2 - Capacitor and manufacturing method thereof - Google Patents

Description

The present invention relates to a sealing technique for sealing a capacitor case and adjusting the pressure inside the case.

In a capacitor such as an electrolytic capacitor, the internal pressure gradually increases due to the generation of hydrogen gas or the like due to the reaction between the capacitor element and the electrolytic solution. Capacitors are equipped with pressure valves that open certain positions of the capacitor case in order to reduce the impact on the surroundings when such internal pressure exceeds the limits of the capacitor case. The life of the capacitor is reached when this pressure relief valve operates.
The capacitance C (unit: [F]) of the capacitor is defined by S [m ² ] as the effective area of the surface of the anode foil facing the cathode foil, and d as the thickness of the oxide film layer formed on the surface of the anode foil. [m], where ε is the dielectric constant of the oxide film,
8.854×10−12×ε・S/d (1)
becomes. Capacitors are required to have a high capacity, but at the same time, they are required to maintain the volume or reduce the size of the product in which they are mounted. In order to increase the capacity of the capacitor while maintaining its size, a method of reducing the thickness d of the formula (1), that is, reducing the thickness d of the oxide film layer formed on the surface of the electrode foil, has been adopted. By the way, the withstand voltage of a capacitor depends on the thickness of the oxide film layer. As the oxide film layer of the electrode foil is made thinner, the withstand voltage of the anode foil is correspondingly lowered, and the application of a DC (Direct Current) voltage increases a so-called leakage current (LC: Leakage Current). When the leakage current increases on the anode foil side and the movement of charges on the electrode surface increases, the reaction amount on the cathode foil side increases according to Faraday's law, and the amount of hydrogen gas generated on the cathode foil side increases. increase, leading to an increase in the internal pressure of the case.

Regarding the increase in case internal pressure due to gas generation, there is an electrolytic capacitor in which a sealing plate is formed with a gas permeable portion for releasing only the gas accumulated in the capacitor case to the outside (for example, Patent Document 1).

JP-A-8-335536

By the way, the sealing plate is formed of a laminate obtained by laminating a plurality of members having different properties, for example. By permeating the gas generated with the sealing of the electrolytic solution, the sealing plate maintains the function of the capacitor and extends the usable period of the high-capacity capacitor.
However, if the rigidity of the liquid-sealing member among the members constituting the laminate is insufficient, the gas pressure regulating section cannot withstand the internal pressure of the generated gas, resulting in abnormal deformation of the member and lamination around the gas pressure regulating section. Partial detachment may occur. If such peeling of the laminate occurs, the electrolytic solution may enter the peeled portion, reach the interface between the external terminal and the sealing plate, and leak from the interface to the outside of the capacitor.
When the electrolytic solution leaks out in this way, there is a problem that the electrolytic solution may adhere to the substrate and electronic parts around the capacitor and damage them.
Patent document 1 does not disclose such a problem, and cannot be solved.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a sealing plate of a capacitor with sufficient rigidity to maintain a gas pressure regulating function.

To achieve the above object, one aspect of the capacitor of the present invention comprises a capacitor element, a capacitor case for housing the capacitor element, and a sealing plate for sealing an opening of the capacitor case, wherein the sealing plate is a laminated body in which a gas-permeable first member and a gas-sealing second member are laminated; , a through-hole formed in the second member of the laminate and the first through-hole covering the through-hole at a position not overlapping the pressing portion and a thin portion set in a predetermined range around the pressing portion; a gas pressure regulating unit that regulates pressure by allowing gas to permeate through a member ;
A liquid blocking part is provided at the opening of the through-hole to allow gas to permeate the through-hole and prevent liquid from entering the through-hole .

In the capacitor described above, the pressing portion may include a terminal component installed on the laminate, and the through hole may be formed in a range separated by 2.0 mm or more from the installation position of the terminal component.
In the above capacitor, the pressing portion is a contact portion between the first member and the end portion side of the capacitor case folded back along the opening portion side, and the through hole extends from the contact position of the end portion. It may be formed in a range separated by 2.0 mm or more in the central direction of the laminate.

In the capacitor described above , the first member may be a rubber material having a hardness of 50 Hs or more and 85 Hs or less in accordance with JIS K6253.

In order to achieve the above object, one aspect of the capacitor manufacturing method of the present invention includes processing for housing a capacitor element in a capacitor case, and lamination of a first member that allows gas to pass through and a second member that seals gas. a pressing portion that presses at least a part of the flat portion of the first member of the laminated body, and a position that does not overlap the pressing portion and a thin portion set in a predetermined range around the pressing portion; At the opening of the through hole of a sealing plate provided with a through hole formed in the second member of and a gas pressure regulating part that regulates pressure by allowing gas to permeate through the first member covering the through hole, A process of installing a liquid blocking part that allows gas to pass through the through hole and prevents liquid from entering, a process of sealing the capacitor case with the sealing plate , and a position at least a predetermined distance away from the through hole. and folding back the end portion of the capacitor case to the sealing plate so as to come into contact with the first member.

ADVANTAGE OF THE INVENTION According to this invention, one of the following effects is acquired.

(1) By preventing functional deterioration of the gas pressure regulating part, it is possible to suppress pressure rise in the capacitor case and extend the life of the capacitor.

(2) Forming the gas pressure regulating part avoiding the area where the rigidity of the laminate is low can prevent the separation of the laminate, the penetration of the electrolyte into the laminate, or the outflow of the electrolyte to the outside of the laminate. .

(3) By forming the through hole avoiding the periphery of the pressed portion caused by contact with the laminate, it is possible to prevent the formation of the gas pressure regulating portion in the thin portion having low rigidity.

Other objects, features and advantages of the present invention will become clearer with reference to the accompanying drawings and embodiments.

It is a figure which shows the example of an external appearance structure of the sealing board which concerns on 1st Embodiment. It is a figure which shows the partial cross section of a sealing board. It is a figure which shows the partial cross section containing the edge part of a sealing plate. 4 is a diagram showing an example of the external configuration of the opening side of the capacitor according to Example 1. FIG. 2 is a cross-sectional view showing an internal configuration example of a capacitor; FIG. It is a figure which shows the structural example of the sealing board which concerns on 2nd Embodiment. A is a cross-sectional view showing a configuration example of a sealing plate according to Example 2, and B is a partially enlarged view showing a configuration of an opening. A is a cross-sectional view showing a configuration example of a sealing plate according to Example 3, and B is a partially enlarged view showing a configuration of an opening. FIG. 5 is a diagram showing the results of Experimental Example 1; FIG. 10 is a diagram showing the results of Experimental Example 2; FIG. 10 is a diagram showing measurement results of Experimental Example 3; 10 is a graph showing the degree of expansion of the capacitor case of Experimental Example 3. FIG.

[First embodiment]
<Structure of sealing plate 2>
FIG. 1 shows an external configuration example of a sealing plate according to the first embodiment. The configuration shown in FIG. 1 is an example, and the present invention is not limited to such a configuration.

A sealing plate 2 shown in A of FIG. 1 is an example of means for sealing an opening of a case for housing a capacitor element or the like, and is, for example, a laminate in which a plurality of members having different functions are laminated. The sealing plate 2 is formed in a shape corresponding to the shape of the opening of the case in which it is installed. be. In addition, when the opening of the case is polygonal, it is formed according to the shape and size.
The sealing plate 2 includes, for example, a rubber layer 4 and a resin layer 6 whose plane portions of the laminate have the same shape.

The rubber layer 4 is an example of the first member of the present disclosure, and has a function of allowing gas to pass through the case in which the sealing plate 2 is installed, but blocking liquid. For the rubber layer 4, a rubber material such as ethylene propylene rubber, butyl rubber, silicone rubber, or the like is adopted. These rubber materials exhibit predetermined flexibility and elasticity. Preferably, a material within the range of 50 [Hs] to 85 [Hs] is adopted. The hardness of this rubber layer 4 is an example, and values lower or higher than this value range may be used. Further, the hardness value may be set to a value equivalent to this range for standards other than JIS that are adopted in areas where sealing plate 2 or capacitors using this sealing plate 2 are manufactured or used, for example. .
Furthermore, the hardness of the rubber layer 4 varies depending on the surrounding environment where the capacitor is installed, the area of use, the test method for hardness measurement, and the standards set by the area of use/manufacturing. can be different.
Further, the rubber layer 4 is set within the range of 0.7 to 1.5 [mm]. If the thickness is less than 0.7 [mm], the gas pressure regulating portion tends to swell due to the internal pressure of the generated gas, and the laminated portion with the resin layer 6 around the gas pressure regulating portion may easily peel off. If it is thicker than 1.5 [mm], the sealing plate 2 becomes thicker, leading to an increase in the size of the capacitor 20 .

The resin layer 6 is an example of the second member of the present disclosure, and paper phenolic resin is used, for example. The paper phenolic resin is a base material of the resin layer 6, and is a synthetic material obtained by impregnating a paper base material with a phenolic resin. The resin layer 6 functions as a supporting material for the sealing plate 2 to maintain the shape of the laminated rubber layer 4, and also blocks gas and liquid in the case in which the sealing plate 2 is installed. The resin layer 6 may have a single structure made of paper phenolic resin, or may have a laminated structure in which other materials (not shown) are superimposed.

Further, the sealing plate 2 has a plurality of external terminals 8 on the central side of the flat plate portion, and functions as a positive terminal 8a and a negative terminal 8b of the capacitor. The external terminal 8 is formed, for example, in an "L" shape (not shown), and is arranged in parallel with a portion protruding from the sealing plate 2 to be brought into contact with a board of an external device, etc., and a plane portion of the sealing plate 2. and is fixed to the planar portion of the sealing plate 2 by rivets 10. As shown in FIG. The rivet 10 is made of a conductive metal material or plated with a metal on its surface, and is electrically connected to the external terminal 8 . The external terminal 8 and the rivet 10 are pressing members that press the flat plate portion of the sealing plate 2, and the portion where the rubber layer 4 is crushed or likely to be crushed by this pressing is the pressing portion of the present disclosure. An example. As shown in FIG. 1B, for example, the rivet 10 penetrates the flat plate surface of the sealing plate 2 through a portion of the external terminal 8 and has a larger diameter than the shaft. A pressing portion is pressed against the flat plate surface of the sealing plate 2 .
A thin portion X is formed on the flat plate surface of the sealing plate 2 by crimping the rivet 10 at a portion overlapping the external terminal 8 and the pressing portion of the rivet 10 and a predetermined range around the portion. The thin portion X has a shape similar to the shape of the external terminal 8 that contacts the flat portion, for example. For example, if the shape of the contact of the external terminal 8 with the rubber layer 4 is circular, the shape of the thin portion X is circular or nearly circular. The thin portion X varies in formation range depending on, for example, the hardness of the rubber material forming the rubber layer 4, the pressing force of the rivet 10, the pressing depth, and the like.

In addition, the sealing plate 2 is formed with a through hole 12 on the plane portion on the resin layer 6 side. One end of the through hole 12 is open to the outside so that gas or liquid can flow into the resin layer 6 . The other end side is covered with a laminated rubber layer 4 . The part of the rubber layer 4 that covers the through hole 12 and the open end is an example of the gas pressure regulating portion of the present disclosure, and of the gas and liquid that enter the through hole 12, only the gas passes through the rubber layer 4. passes through the sealing plate 2. The sealing plate 2 adjusts the gas pressure inside the case sealed by the sealing plate 2 by blocking the liquid with the rubber layer 4 .
The through hole 12 is formed at a position that does not overlap the thin portion X of the rubber layer 4 caused by the external terminal 8 or the rivet 10, for example. In addition, when a thin portion X is formed in the rubber layer 4 by a pressing member other than the external terminal 8 or the rivet 10 in the sealing plate 2, the through hole 12 is formed at a position that does not overlap the thin portion X either.

<Position of the gas pressure regulator from the external terminal>
FIG. 2 shows a partial cross section of the sealing plate.
In the sealing plate 2, for example, as shown in FIG. 2, a thin portion X of the rubber layer 4 spreads around the penetrating portion of the external terminal 8 and the rivet 10. As shown in FIG. The thin portion X has the smallest thickness dx at the portion with which the external terminal 8 and the rivet 10 contact, for example, and the thickness d1 at which the thin portion X is not pressed becomes smaller as the distance from the contact portion increases. For example, the thickness dx of the thin portion X may change proportionally according to the separation distance, or may vary depending on the distance from the pressed portion.
A through-hole 12 functioning as a gas pressure regulating portion is formed outside the range of the thin portion X. As shown in FIG. The through hole 12 is formed within a range of 1.5 [mm] or more, preferably 2.0 [mm] or more, as a predetermined distance L1 from the end of the external terminal 8 or the rivet 10. be. That is, the thin portion X is affected by any one of the material and hardness of the rubber layer 4, the size of the thickness d1, the pressing force of the rivet 10, or a combination of two or more of these conditions. Therefore, in the sealing plate 2, for example, the forming range of the thin portion X for the conditions of the rubber layer 4 set in advance is obtained, and the gas pressure adjusting portion is formed in a range separated from the forming range of the thin portion X.

In the process of forming the through holes 12, for example, instead of determining the predetermined distance L1 to be separated from only one external terminal 8 or rivet 10 on the flat portion of the sealing plate 2, all or a predetermined number of external terminals on the flat portion are determined. 8 or whether or not the rivet 10 is separated by a predetermined distance L1. As a result, of the flat plate surface of the sealing plate 2, for example, the range where the anode terminal 8a and the cathode terminal 8b face each other may be within the range of the thin portion X formed by either or both of these external terminals. In some cases, the holes 12 cannot be formed.
The opening diameter L2 of the through hole 12 may be set based on the type of gas to be permeated as the gas pressure regulating portion and the amount of gas generated in the sealed capacitor case. good.

<Position of the gas pressure regulating part from the edge of the sealing plate>
FIG. 3 shows a partial cross section including the edge of the sealing plate.
In the sealing plate 2, for example, on the plane of the laminate, a through hole 12, which is a gas pressure adjusting portion, is formed in the resin layer 6 within a range spaced apart by a predetermined distance L3 from the outer peripheral edge toward the center of the plane. . This predetermined distance L3 includes, for example, a distance L4 where the front end portion 14 side of the case is folded back by crimping the capacitor case and pressed against the sealing plate, and a predetermined distance L5 from this front end side of the case. The distance L4 by which the case tip portion 14 is folded back is, for example, 1.5 to 4.0 [mm], and the distance L5 from the case tip portion is, for example, a value larger than 1.5 [mm], and more preferably. is set to a value of 2.0 [mm] or more.
The case tip 14 is folded back to stabilize the contact state between the capacitor case and the sealing plate 2, for example, and to prevent foreign matter from entering the joint portion between the peripheral surface of the sealing plate 2 and the case. to crush the rubber layer 4. That is, the rubber layer 4 is formed with a pressing portion by the case front end portion 14, and a thin portion X of the sealing plate 2 is formed in the pressing portion and a predetermined range around it. That is, the tip portion 14 of the case is an example of a pressing member.

In determining the formation position of the through hole 12, for example, whether or not it is the thin portion X may be measured and managed, or based on information on the pressing force of the rivet 10, the material forming the rubber layer 4, and its hardness. Alternatively, information measured in advance in a laboratory or the like may be used.

<Manufacturing process of sealing plate 2>

Here, an example of the manufacturing process of the sealing plate 2 will be described.

(A) Laminated material production process In this process, for example, a paper phenol resin material is produced. The material produced here is in a semi-cured state called, for example, prepreg. In producing a paper phenolic resin material, for example, a paper substrate is impregnated with a solution of a phenolic resin before cross-linking dissolved in alcohol or the like, and heated and dried to produce a semi-cured state. Then, the planar portions of the paper phenolic resin material and the rubber material of the prepreg thus formed are overlaid to form a laminated material. Then, this laminated material is heat-pressed to be integrated. Thus, a laminate having the rubber layer 4 and the resin layer 6 is produced.
(B) Sealing plate forming process In this process, the sealing plate 2 is formed into a predetermined shape. The produced laminated material is punched into the shape and size of the sealing plate 2 by, for example, pressing. At this time, the laminate is cut, for example, by shearing blades of a press.
(C) Process for Forming Gas Pressure Regulating Portion The laminated material formed by press working has, for example, the installation positions of the external terminals 8 and the rivets 10, and/or a predetermined distance from the outer circumference of the laminated body toward the center. A plurality of through holes 12 are formed within the range. The through-hole 12 is formed by cutting from the surface where the flat portion of the resin layer 6 is exposed, using a tool such as a dedicated drill, to shave the thickness up to the portion where the rubber layer 4 is laminated.
(D) Other processing In the sealing plate 2, for example, the external terminal 8 is penetrated through a part of the rivet 10 to the central side of the laminate. The pressing force of the rivet 10 may be, for example, a preset value, and may be set according to the thickness of the laminate or the rubber layer 4, the hardness of the rubber layer 4, and the like. When installing the external terminals 8 using the rivets 10 , for example, in order to bring the external terminals 8 into close contact with the sealing plate 2 , the pressing force is set so that the rubber layer 4 has a predetermined thickness dx, and the external terminals are attached to the sealing plate 2 . 8 should be installed.

[Effects of the first embodiment]

According to such a configuration, the following effects are obtained.

(1) Since the gas pressure regulating part including the through-hole is not formed in the area overlapping the thin-walled part X generated in the sealing plate, the rigidity of the rubber layer can be maintained, and the internal pressure applied to the through-hole from the capacitor case, etc. causes the rubber layer to break down. Abnormal expansion can be prevented.
(2) Since the rigidity of the rubber layer is prevented from being lowered by the thin portion X, the gas pressure regulating function of allowing gas to permeate through the rubber layer can be maintained, and the life of the capacitor can be extended.
(3) By not providing the gas pressure regulating portion in the range of the thin portion X, it is possible to prevent part of the laminate formed of the rubber layer and the resin layer from being peeled off or damaged.
(4) In addition, the rubber layer that maintains its rigidity does not cause peeling or damage to a part of the laminate, and the electrolytic solution of the capacitor does not enter or remain in the peeled part, so the gas pressure regulator functional deterioration can be prevented.
(5) Leakage of the electrolyte from the gas pressure regulating section can be prevented, and short-circuiting due to contact between the external terminal or the substrate or device to which the external terminal is connected and the electrolyte can be prevented.
(6) By setting the formation position of the through-hole, assuming in advance the range where the thin-walled portion X will occur on the flat plate surface with respect to the hardness of the rubber material, the size of the external terminal, the rivet, or the pressing force, The load for forming the sealing plate can be reduced.

FIG. 4 shows an external configuration example of the capacitor according to the first embodiment.
In this capacitor 20, for example, as shown in FIG. 4, a sealing plate 2 seals an opening 24 of a case 22 that accommodates a capacitor element 30 (FIG. 5). The sealing plate 2 has the rubber layer 4 exposed to the outside of the case 22 and the resin layer 6 arranged inside the case 22 .
The end portion of the case 22 is folded back on the side of the opening 24 of the case 22 to cover the flat portion along the outer peripheral surface of the sealing plate 2 . In addition, on the side surface of the case 22, a crimping portion is formed by recessing a part of the case to match the peripheral surface of the sealing plate 2 arranged in the case 22, and presses the sealing plate 2 in the case 22. Alternatively, the arrangement position of the sealing plate 2 is fixed by placing the sealing plate 2 in the recess.

The sealing plate 2 has, for example, four through holes 12 at positions sandwiching the anode terminal 8a and the cathode terminal 8b. do.

The case 22 is, for example, a cylindrical container with a bottom as shown in FIG. 5, and has a storage portion for storing the capacitor element 30, an electrolyte (not shown), and other items. A fragile portion (not shown) having a predetermined shape is formed at the bottom of the case 22, and is configured to break when the pressure inside the case 22 exceeds a certain value. This fragile portion is set to break at a pressure lower than the value at which the sealing plate 2 breaks, for example. In this manner, the capacitor 20 avoids serious damage to the capacitor itself and the equipment in which the capacitor is installed by breaking the intended parts in advance against the increase in internal pressure.
Capacitor element 30 is a wound element in which electrode foil and a separator are wound, and is formed in a size and shape that can be accommodated in a storage portion of case 22 . Capacitor element 30 is wound in a predetermined direction in a state in which, for example, electrode foils (not shown) such as anode foil and cathode foil are laminated with a separator as an insulator interposed therebetween. A flat plate portion of the sealing plate 2 is arranged so as to face this winding end surface.
Capacitor element 30 has tabs 32a and 32b protruding from the anode foil and the cathode foil on the winding surface on one end side, respectively.
<Capacitor manufacturing process>
As a manufacturing process of the capacitor 20, the capacitor element 30 is housed in the housing portion of the case 22 when the tabs 32a and 32b are connected to the anode terminal 8a and the cathode terminal 8b.
After the capacitor element 30 and the like are placed in the housing portion of the case 22, the front end portion 14 on the opening portion 24 side is folded back toward the sealing plate 2 side to be in a sealed state.
In addition, the case 22 is pressurized from the outside at a position close to the lower side of the sealing plate 2 or at a position overlapping the sealing plate 2, for example, to form a crimping groove so that the sealing plate 2 and the case 22 are brought into close contact with each other. Let The tip portion 14 of the case 22 is brought into contact with the rubber layer 4 of the sealing plate 2 so as to press it. As a result, even if the internal pressure of the capacitor rises, it is possible to prevent the sealing plate 2 from separating from the case 22 .

In the capacitor 20, the electrolytic solution undergoes a chemical reaction due to long-term use and use environment, gas is generated, and the internal pressure of the case increases. In response to this increase in internal pressure, the sealing plate 2 takes in the generated hydrogen gas HG into the through hole 12, permeates the rubber layer 4, and discharges the hydrogen gas HG to the outside of the case 22 by a predetermined amount.
Further, when the electrolytic solution comes into contact with the sealing plate 2 side due to the increase in the internal pressure of the case 22, even if the electrolytic solution enters the through hole 12, it is blocked by the rubber layer 4 and is prevented from flowing out of the case 22. are preventing.

Although the capacitor 20 shown in FIG. 5 is arranged with the opening 24 facing upward, the present invention is not limited to this. A case in which the opening 24 is directed laterally or downward is also included according to the equipment that utilizes the capacitor 20 .

<Effect of Example 1>

According to such a configuration, the following effects can be obtained in addition to the effects shown in the first embodiment.

(1) The sealing plate 2 is arranged with no gap in relation to the case 22, and the rubber layer 4 of the sealing plate 2 blocks the electrolytic solution.

(2) By folding back the tip portion 14 of the case 22 and pressing it against the rubber layer 4 of the sealing plate 2 , the periphery of the end surface of the sealing plate 2 can be firmly integrated with the case 22 .

(3) As the sealing plate 2 and the case 22 are integrated, the increase in the internal pressure of the case 22 is suppressed by the gas pressure adjusting portion formed by the through hole 12 and the rubber layer 4, so that the life of the capacitor 20 can be extended.

[Second embodiment]
FIG. 6 shows a configuration example of a sealing plate according to the second embodiment. The configuration shown in FIG. 6 is an example, and the present invention is not limited to such a configuration. Moreover, in FIG. 6, the same reference numerals are given to the same parts as in FIGS.
This sealing plate 2 has the following configuration in addition to the configuration shown in the first embodiment and the first embodiment.
The sealing plate 2 has, for example, as shown in FIG. 6, a liquid cutoff plug 40 inserted into the through hole 12, which is the gas pressure regulating section, to prevent liquid from entering. The liquid shut-off plug 40 is an example of the liquid shut-off part of the present invention, and is made of plastic such as polypropylene or ceramic, through which reaction gas generated by the reaction between the capacitor element and the electrolytic solution permeates, but through which liquid components such as the electrolytic solution do not permeate. Or it is composed of a resin material. The liquid shutoff plug 40 may be molded into a predetermined shape, for example, and inserted into the through hole 12. Alternatively, the through hole 12 may be filled with a liquid or gel resin material, and the through hole 12 may be filled with a liquid or gel resin material. It may be molded according to the internal shape.

The liquid blocking plug 40 may be filled or inserted into the entire interior of the through hole 12, or at least block the opening of the through hole 12 facing the inside of the case 22 where the capacitor element is arranged. As a result, the electrolytic solution, condensed water, and the like that have flowed toward the opening of the through-hole 12 cannot enter the through-hole 12 due to the liquid blocking plug 40 .
The liquid shut-off plug 40 may be formed when the sealing plate 2 is manufactured. For example, the resin material is filled or inserted after the through-hole 12 is formed. The liquid block plug 40 may be filled or inserted with a resin material after the rivet 10 is installed on the sealing plate 2 or before the sealing plate 2 is installed on the case 22 .
In addition, in the manufacturing process of the capacitor, in addition to the manufacturing process of the sealing plate 2 shown in the first embodiment, as the process of installing the liquid blocking part, a solid liquid blocking plug 40 is inserted into the through hole 12. Alternatively, a process of filling with a liquid or gel resin material may be performed.

<Effects of Second Embodiment>
According to such a configuration, the same effects as those of the first embodiment and the first embodiment can be obtained, and the following effects can be expected.
(1) By preventing moisture such as electrolyte from entering the through-hole 12 with the liquid blocking plug 40, it is possible to prevent deterioration of the gas pressure regulation function due to water droplets adhering to the inner wall of the through-hole 12 and the surface of the rubber layer 4.
(2) By arranging the liquid shutoff plug 40 at the opening of the through hole 12, it is possible to prevent the inlet of the gas pressure regulator from being shut off by water droplets.
(3) Regardless of how the capacitor is installed, such as when the sealing plate 2 faces downward or is inclined, the liquid shut-off plug 40 prevents the electrolytic solution in the case 22 from entering the through hole 12, thereby sealing the capacitor. The gas pressure regulation function of the plate 2 can be maintained.

FIG. 7 shows a configuration example of the sealing plate according to the second embodiment.
In this sealing plate 2, for example, as shown in A of FIG. For example, one end of the liquid blocking plug 50 is inserted into the through hole 12 and the other end protrudes from the opening of the through hole 12 .
The liquid blocking plug 50 includes, for example, a blocking portion 52 inserted into the through hole 12 and a liquid separation portion 54 projecting from the opening, as shown in FIG. 7B.

The blocking portion 52 is a portion that blocks at least the opening side of the through hole 12 to prevent the electrolyte from entering the through hole 12 . A space is formed between the blocking portion 52 and the rubber layer 4 according to, for example, the length and insertion amount of the liquid blocking plug 50 .
The liquid separating portion 54 is an example of a functional portion that prevents liquid from remaining on the opening of the through-hole 12 or on the blocking portion 52 installed in this opening. The liquid separating portion 54 is formed to extend toward the inside of the case with respect to the blocking portion 52 . That is, the liquid separating portion 54 is formed so as to protrude from the surface of the sealing plate 2, thereby separating the water droplets generated in the case from the surface of the resin layer 6 and making it difficult for the water droplets to stay. In addition, the liquid blocking plug 50 can secure a large surface area with respect to the inside of the case by protruding the liquid separating portion 54 from the resin layer 6 . As a result, even if water droplets generated in the case adhere to the surface of the resin layer 6, a gas permeation path to the blocking portion 52 side in the through hole 12 can be secured.

The blocking portion 52 and the liquid separation portion 54 are functionally divided by the opening of the through hole 12 as a boundary, and the length of each is determined by the amount of insertion of the liquid blocking plug 50 . Further, the liquid shutoff plug 50 is not limited to the one in which the shutoff part 52 and the liquid separation part 54 are integrally formed, and may be formed of separate members and integrated at the opening of the through hole 12 .

The entire length of the liquid blocking plug 50 may be formed shorter than the depth of the through-hole 12 , that is, the thickness of the resin layer 6 , or may be formed to have an equivalent length or longer than the through-hole 12 . You may Inside the through-hole 12, for example, the tip of the liquid blocking plug 50 may be brought into contact with the rubber layer 4, or the insertion amount may be adjusted so as to form a space between the liquid blocking plug 50 and the rubber layer 4. do it.
In addition, in the process of inserting the liquid block plug 50 into the through hole 12 , the liquid separating portion 54 may be formed outside the through hole 12 .

[Effect of Example 2]
According to such a configuration, the same effects as those of the above-described embodiment can be obtained, and the following effects can be expected.
(1) By protruding a part of the liquid shutoff plug 50 from the through hole 12, it becomes difficult for the liquid adhering to the surface of the sealing plate 2 to cover the entire liquid shutoff plug 50, and the gas pressure regulating part through the through hole 12 is prevented. functions can be ensured.
(2) The liquid blocking plug 50 may be partially protruded from the through-hole 12, and the filling amount of the resin material and the insertion amount of the liquid blocking plug 50 do not need to be adjusted and managed. can be simplified.

FIG. 8 shows a configuration example of a sealing plate according to the third embodiment.
In this sealing plate 2, as shown in FIG. 8A, for example, a liquid blocking film 60 is installed so as to cover the opening of the through hole 12. As shown in FIG. The liquid blocking film 60 is an example of the liquid blocking portion of the present invention, and is made of a resin material having a gas-liquid separation function, and is formed with an area covering at least the opening of the through hole 12 and a predetermined range of the peripheral edge portion thereof. It is The liquid blocking film 60 is adhered, for example, to the surface of the resin layer 6 by fixing means such as an adhesive (not shown).
For example, as shown in FIG. 8B, the liquid blocking film 60 includes a blocking portion 62 that covers the opening of the through hole 12 and a liquid separating portion 64 that is integrally formed with the blocking portion 62 and covers the periphery of the opening. Prepare.
It should be noted that the blocking portion 62 and the liquid separation portion 64 are functionally separated with the opening of the through hole 12 as a boundary. In the liquid blocking film 60 , the blocking portion 62 and the liquid separation portion 64 may be configured as separate members and integrated at the opening of the through hole 12 .

The liquid blocking film 60 may have a flat surface facing the inside of the case (not shown), or may be inclined so that the central portion protrudes toward the inside of the case at the apex. In this case, the liquid blocking film 60 is formed parallel to the surface of the resin layer 6 on one side, and has a different thickness toward the center of the opening of the through hole 12 on the opposite side. Just do it. As a result, it is possible to maintain close contact with the resin layer 6 and prevent water droplets from remaining on the blocking portion 62 .

[Effect of Example 3]
According to such a configuration, the same effects as those of the above-described embodiment can be obtained, and the following effects can be expected.
(1) By covering the opening of the through-hole 12 and its peripheral portion with the liquid blocking film 60, the liquid adhering to the surface of the sealing plate 2 can be prevented from blocking the through-hole 12, and the gas can be adjusted through the through-hole 12. The function of the pressure section can be secured.
(2) By sticking the liquid blocking film 60 on the basis of the through hole 12, it is possible to prevent water such as electrolyte from entering the through hole 12, thereby simplifying the processing.

<Experimental example 1>

Next, an experimental example of the gas pressure adjustment performance of the sealing plate will be shown. 9 is a diagram showing the results of Experimental Example 1. FIG.
In this experiment, the relationship between the formation position of the gas pressure regulating portion of the sealing plate 2 and its regulating function is measured. Specifically, the distance (L1) between the external terminal 8 of the sealing plate 2 and the through hole 12 determines whether or not the gas pressure regulating section functions normally.
The capacitor used in this experiment has a size of φ30×40 [L], a rating of 450 [V] and 390 [μF], an electrolytic paper made of kraft paper, and an electrolytic solution containing ethylene glycol as a main solvent. In the sealing plate 2, the distance (L1) between the outermost peripheral portion of the contact portion of the external terminal 8 with the rubber layer 4 and the through hole 12 is 1.0 [mm] and 1.5 [mm], respectively. , 2.0 [mm] and 3.0 [mm] were prepared respectively.
In addition, the test conditions were as follows: a voltage of 450 [WV] was applied at 105 [°C] in the ambient environment; After [time], the state of electrolyte leakage was observed.

Under all conditions, at the start of the experiment, there was no leakage of the electrolyte and no abnormality was found.
(1) When the distance (L1) between the external terminal and the through-hole is 1.0 [mm] After 500 [hours] have passed, two out of the five prepared capacitors are exposed to the outside of rubber layer 4 of sealing plate 2. Liquid leakage was confirmed around the terminal 8 .
After 1000 [hours] had passed, liquid leakage was confirmed around the external terminals 8 of the rubber layer 4 of the sealing plate 2 in 3 of the remaining 3 capacitors.
(2) When the distance (L1) between the external terminal and the through-hole is 1.5 [mm] There was no leakage of the electrolytic solution for 1000 [hours] from the start of the experiment, and there was no abnormality. However, after 2000 [hours] elapsed, liquid leakage was confirmed around the external terminal 8 of the rubber layer 4 of the sealing plate 2 in one of the five capacitors prepared. Further, after 5000 [hours] had passed, liquid leakage was confirmed around the external terminals 8 of the rubber layer 4 of the sealing plate 2 in two of the remaining four capacitors.
(3) When the distance (L1) between the external terminal and the through-hole is 2.0 [mm] Even after 5000 [hours] have passed since the start of the experiment, the electrolyte did not leak into the capacitor, and there was no abnormality. .
(4) When the distance (L1) between the external terminal and the through-hole is 3.0 [mm] Even after 5000 [hours] have passed since the start of the experiment, the electrolyte did not leak into the capacitor and there was no abnormality. .

From the results of Experimental Example 1, there is a thin portion X formed by pressing the rivet 10 in a range of 1.5 mm from the installation position of the external terminal, and the through hole 12 is formed in the thin portion X portion. If there is, the electrolytic solution leaks from the periphery of the external terminal 8 of the rubber layer 4 of the sealing plate 2 before 2000 [hours] have elapsed since the start of application to the capacitor. The gas generated in the case 22 presses the rubber layer 4 that closes the through hole 12 so as to swell toward the outside of the sealing plate 2 . Since the thickness of the rubber layer 4 covering the portion 12 is also reduced, it becomes easier to swell. Then, since the rubber layer 4 covering the through hole 12 swells in the direction away from the resin layer 6 , when the elongation of the rubber layer 4 exceeds the allowable amount, the rubber layer 4 separates from the resin layer 6 around the through hole 12 . do. When the detachment reaches the external terminal 8, a flow path for the electrolytic solution is formed. In other words, the electrolyte leaks out through the gap between the rubber layer 4 and the resin layer 6 separated from the through hole 12 and the interface between the external terminal 8 and the sealing plate 2, causing liquid leakage.
Therefore, as in the present invention, the sealing plate 2 has a gas pressure regulating portion formed in a range spaced apart from the installation position of the external terminal by 2.0 mm or more, so that the rubber layer 4 covering the through hole 12 is formed. Since the thickness is not reduced, the rubber layer 4 does not swell outward due to the internal pressure of hydrogen gas generated inside the case. can be made available for over 5000 [hours].

<Experimental example 2>

Next, an experimental example of the gas pressure adjustment performance of the sealing plate will be shown. 10 is a diagram showing the results of Experimental Example 2. FIG.
In this experiment, the relationship between the formation position of the gas pressure regulating portion of the sealing plate 2 and its regulating function is measured. Specifically, it is determined whether or not the gas pressure regulating section functions normally based on the distance (L5) between the portion where the flat portion of the sealing plate and the tip of the case are folded back and contact with the through hole 12 .
The rating, size, and test conditions of the capacitor used in Experimental Example 2 are the same as in Experimental Example 1.
The positions of the through-holes formed in the sealing plate 2 are such that the distance (L5) between the crimped rubber layer and the tip of the case is 1.0 [mm], 1.5 [mm], and 2.0 mm, respectively. [mm] and 5 sets of 3.0 [mm] were prepared respectively.

The results of this experiment are shown in FIG.
Under all conditions, at the start of the experiment, there was no leakage of the electrolyte and no abnormality was found.
(1) When the distance (L5) between the tip of the case and the through-hole is 1.0 [mm] After 500 [hours] have elapsed, the rubber layer 4 of the sealing plate 2 of 2 out of 5 prepared capacitors Liquid leakage was confirmed in the portion covering the through hole 12 .
After 1000 [hours] had passed, three of the remaining three capacitors were confirmed to have leaked from the portion of the rubber layer 4 of the sealing plate 2 covering the through hole 12 .
Since the through-hole was filled with electrolyte, there are no further measurement results.
(2) When the distance (L5) between the tip of the case and the through-hole is 1.5 [mm] There was no leakage of the electrolytic solution until 500 [hours] had elapsed from the start of the experiment, and no abnormality was found. However, after 1000 [hours] elapsed, liquid leakage was confirmed in the portion covering the through hole 12 of the rubber layer 4 of the sealing plate 2 in one of the five prepared capacitors. Further, in all the capacitors remaining after 2000 [hours] elapsed, liquid leakage was confirmed in the portion of the rubber layer 4 of the sealing plate 2 covering the through hole 12 .
(3) When the distance (L5) between the tip of the case and the through hole is 2.0 [mm] Even after 5000 [hours] have passed since the start of the experiment, no electrolyte leaked into the capacitor and no abnormality was found. rice field.
(4) When the distance (L5) between the tip of the case and the through-hole is 3.0 [mm] Even after 5000 [hours] have passed from the start of the experiment, no electrolyte leaked into the capacitor and no abnormality was found. rice field.

From the results of this Experimental Example 2, there is a thin portion X formed by crimping by the case tip portion within a range of 1.5 mm from the case tip portion, and this thin portion X has a through hole 12. Then, the electrolytic solution leaks out from the portion of the rubber layer 4 of the sealing plate 2 covering the through hole 12 until 2000 [hours] have elapsed since the start of application to the capacitor. The gas generated in the case 22 presses the rubber layer 4 that closes the through hole 12 so as to swell toward the outside of the sealing plate 2 . Since the thickness of the rubber layer 4 covering the portion 12 is also reduced, it becomes easier to swell. As a result, the portion of the rubber layer 4 covering the through-hole 12 swells in the direction away from the resin layer 6, so if the elongation of the rubber layer 4 exceeds the allowable amount, the portion of the rubber layer 4 covering the through-hole 12 cracks. , the electrolyte leaks to the outside, causing liquid leakage. Also, as described above, when the elongation of the rubber layer 4 exceeds the allowable amount, the rubber layer 4 separates from the resin layer 6 from the periphery of the through hole 12, and when the separation reaches the external terminal 8 or the outer periphery of the sealing plate 2, electrolysis occurs. A liquid outflow path may be formed.
In addition, when compared with the results of Experimental Example 1, regardless of whether the pressing member that presses the rubber layer of the sealing plate is the external terminal or the tip of the case, the results of liquid leakage with respect to the distance to the through-hole and the elapsed time are the same. or something close to it. That is, the gas pressure adjusting portion of the sealing plate depends on the distance at which the thin portion X is formed.
Therefore, as in the present invention, the sealing plate should be provided with a gas pressure regulating portion in a range separated by 2.0 [mm] or more from the contact portion of the external terminal with the rubber layer and the contact position of the tip of the case. Therefore, the function of discharging hydrogen gas generated inside the case can be maintained, and the capacitor can be used for 5000 hours or more.

<Experimental example 3>

Next, an experimental example regarding the state of the gas pressure regulating function will be shown. FIG. 11 shows the measurement results of Experimental Example 3, and FIG. 12 shows the degree of expansion of the capacitor case.
In this experiment, the relationship between the gas pressure regulation function and the expansion state inside the capacitor case is measured. Specifically, the effect of the gas pressure regulating function of the sealing plate 2 and the maintenance of the gas pressure regulating function by the liquid blocking portion are determined from the expansion state of the capacitor case.

In Experimental Example 3, a capacitor with a size of φ30×40 [L], a rating of 450 [V] and 390 [μF], an electrolytic paper made of kraft paper, and an electrolytic solution containing ethylene glycol as a main solvent is used. . The sealing plate 2 has a distance (L1) between the through-hole 12 and the external terminal 8 of approximately 8.2 [mm], and a distance (L5) between the through-hole 12 and the tip of the case of approximately 4.2 [mm]. and Further, the sealing plate 2 has, as a configuration on the experimental side, a hollow through-hole 12 in the resin layer 6 (first embodiment), and silicone resin is filled inside the through-hole 12 as a liquid blocking portion 40 . An enclosed one (second embodiment) and one in which the opening of the through-hole 12 and its peripheral portion were covered with a PP (polypropylene) tape (Example 3) were prepared.
As for the sealing plate 2, as experimental comparative examples, one without the through holes 12 (Comparative Example 1) and one in which the electrolyte penetrated into the through holes 12 (Comparative Example 2) were prepared.
Five capacitors are used for each condition.
Then, the test conditions were as follows: a voltage of 450 [WV] was applied at 105 [°C] in the ambient environment, and the amount of expansion of the case after 0 [hour] at the start of the experiment, 250 [hours] after the start, and 500 [hours]. is measured and the average value of 5 is calculated.

The results of this experiment are shown in FIG.
(1) In the configuration shown in the second embodiment in which the through hole 12 is filled with silicon resin, the expansion amount of the case after 250 [hours] is 0.53 [mm], and after 500 [hours] The expansion amount of the case was 0.58 [mm].
(2) In the configuration shown in Example 3, in which the opening of the through-hole 12 was covered with the PP tape, the amount of expansion of the case after 250 [hours] was 0.6 [mm], and after 500 [hours] The expansion amount of the case was 0.6 [mm].
(3) In the configuration shown in the first embodiment in which the opening of the through hole 12 is open, the amount of expansion of the case after 250 [hours] is 0.52 [mm], and after 500 [hours] case expansion amount was 0.52 [mm].
(4) In Comparative Example 1 using a sealing plate without a through hole, the amount of expansion of the case after 250 [hours] was 0.67 [mm], and the amount of expansion of the case after 500 [hours] was 0. .74 [mm].
(5) In Comparative Example 2 in which the electrolyte penetrated into the through hole 12, the amount of case expansion after 250 [hours] was 0.65 [mm], and the case expansion after 500 [hours] had passed. The amount became 0.7 [mm].

FIG. 12 shows how the cases change over time.
For example, as shown in FIG. 12, such measurement results are obtained in the third embodiment (measurement result (2)) and the first embodiment (measurement result (3)) among the structures provided with the through holes 12. After 250 hours from the start of the experiment after the voltage was applied to the capacitor, the amount of expansion of the case was maintained at the same magnitude regardless of the passage of time. That is, the expansion of the case is suppressed by discharging the gas generated in the case by the gas pressure regulating function including the through hole 12 .

In the second embodiment (measurement result (1)), the expansion of the case progresses between 250 [hours] and 500 [hours]. Compared to the results (4) and (5)), the amount of expansion in the case is a small value. From this result, it is shown that the larger the amount of swelling, the less gas permeates, the higher the internal pressure, and the more the bottom of the case swells.

Comparing the first embodiment (measurement result (3)) with the comparative example 1 (measurement result (4)), it can be seen that the gas pressure regulating function including the through hole 12 and the rubber layer 4 releases the gas inside the case. It has been shown to be possible and not bloat the case.
Further, when comparing the second embodiment (measurement result (1)) and the third embodiment (measurement result (2)) provided with a gas pressure regulating section with the comparative example 2 (measurement result (5)), the penetration It has become clear that the gas pressure regulation function is lowered or does not function due to the intrusion of the electrolytic solution into the hole 12 .

From Experimental Example 3, it is clear that the expansion of the case due to the gas generated by the operation of the capacitor can be suppressed by providing the gas pressure regulating portion in the sealing plate 2 . Moreover, it was confirmed that the gas pressure regulation function might deteriorate due to the intrusion of moisture such as the electrolytic solution into the through hole 12 that constitutes the gas pressure regulation function.
Therefore, as in the present invention, when there is a possibility that the electrolyte may enter the sealing plate 2 depending on the usage conditions, installation environment, and installation state of the capacitor, a liquid blocking section is provided for the gas pressure regulating section. is desirable.

[Other embodiments]

Features and modifications of the embodiments described above are listed below.

(1) In the above embodiment, the opening shape of the through-hole 12, which is the gas pressure regulating portion, is circular, but it is not limited to this. The through hole 12 may be formed in a polygonal shape other than a circular shape.
(2) The plurality of through holes 12 formed in the sealing plate 2 are not limited to all having the same diameter. The through-holes 12 may have different opening diameters, for example, depending on the position and number of them.
(3) The number of openings, opening positions, and opening diameters of the through holes 12 may be set according to the hardness of the rubber material forming the rubber layer 4, for example.
(4) In the above-described embodiment, in the manufacturing process of the sealing plate 2, the case where the through holes 12 are formed by scraping only the resin layer 6 is shown, but the present invention is not limited to this. In the process of forming the through-holes 12, the surface side of the rubber layer 4 may be partly scraped. As a result, the gas-impermeable resin layer 6 does not remain in the through hole 12, so that the function of the gas pressure regulating section can be exhibited.

As described above, the most preferable embodiment and the like of the present invention have been described. The invention is not limited to the above description. Various modifications and changes are possible for those skilled in the art based on the gist of the invention described in the claims or disclosed in the detailed description. It goes without saying that such modifications and changes are included in the scope of the present invention.

According to the capacitor and the manufacturing method thereof of the present invention, the gas pressure regulating portion is formed by avoiding the thin portion formed on the planar portion of the sealing plate, so that the gas permeation function of the sealing plate can be maintained. It is useful for maintaining the life of the capacitor.

2 sealing plate 4 rubber layer 6 resin layer 8 external terminal 8a anode terminal 8b cathode terminal 10 rivet 12 through hole 14 case tip 20 capacitor 22 case 24 opening 30 capacitor element 32a, 32b tabs 40, 50 liquid block plug 52, 62 Blocking parts 54, 64 Liquid separating part 60 Liquid blocking membrane

Claims (5)

a capacitor element;
a capacitor case that houses the capacitor element;
a sealing plate that seals the opening of the capacitor case;
wherein the sealing plate is
a laminated body in which a first member that permeates gas and a second member that seals gas are laminated;
a pressing portion that presses at least a part of the planar portion of the first member of the laminate;
a through hole formed in the second member of the laminate and a first member covering the through hole at a position not overlapping the pressing portion and a thin portion set in a predetermined range around the pressing portion; a gas pressure regulating unit that regulates the pressure by allowing gas to permeate through the
a liquid blocker installed at the opening of the through-hole to allow gas to pass through the through-hole and prevent liquid from entering;
A capacitor comprising: The pressing part includes a terminal component installed on the laminate,
2. The capacitor according to claim 1, wherein said through-hole is formed in a range separated by 2.0 mm or more from the installation position of said terminal component. the pressing portion is a contact portion between the first member and the end portion side of the capacitor case folded back along the opening portion side,
3. The capacitor according to claim 1, wherein said through-hole is formed in a range of 2.0 mm or more away from the contact position of said end toward the center of said laminate. 4. The capacitor according to any one of claims 1 to 3 , wherein said first member is made of a rubber material having a hardness of 50 Hs or more and 85 Hs or less in accordance with JIS K6253. A method for manufacturing a capacitor,
a process of housing the capacitor element in a capacitor case;
a pressing portion for pressing at least a part of a plane portion of the first member of a laminated body in which a first member permeable to gas and a second member for sealing gas are laminated; Gas is permeated through a through-hole formed in the second member of the laminate and the first member covering the through-hole at a position not overlapping a thin-walled portion set in a predetermined range around the pressing portion. A process of installing a liquid blocking part that allows gas to pass through the through hole and prevents liquid from entering into the through hole in the opening of the through hole of the sealing plate provided with a gas pressure adjusting part that adjusts the pressure by
a process of sealing the capacitor case with the sealing plate ;
a process of folding back the end of the capacitor case to the sealing plate so as to contact the first member at a position spaced apart from the through hole by a predetermined distance or more;
A method of manufacturing a capacitor, comprising:

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