Capacitor, and manufacturing method

Abstract

To fix a position of a capacitive element and secure sufficient insulation performance.SOLUTION: A capacitor (1) includes: a capacitive element (10) including a pair of external terminals (13) and a wound body (11) positioned between the pair of electrodes; an exterior container (30); an interior container (50) which has the capacitive element arranged therein, is positioned between the capacitive element and the exterior container and is made of a resin; and a second resin (40) which is made to fill insides of the interior container and the exterior container.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a capacitor. [Background technology]

[0002] It is known that the performance of a capacitance element of a capacitor deteriorates when the capacitance element comes into contact with water vapor and oxygen, and therefore, in order to prevent the deterioration of performance, the capacitance element of the capacitor is molded with resin. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2005-294589 A Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, in order to ensure moisture resistance, the capacitance element is covered with a resin that does not contain filler, and after hardening, it is resin-molded into the shape of a capacitor with a resin that contains filler. However, the insulating performance of the capacitor changes depending on the position of the capacitance element relative to the capacitor container. Therefore, the insulating performance may change as the resin is injected.

[0005] An object of one embodiment of the present invention is to arrange a capacitive element so as to provide a sufficient insulating performance for a capacitor. [Means for solving the problem]

[0006] In order to solve the above problems, the capacitor of the present invention comprises a capacitive element including a pair of electrodes and a dielectric located between the pair of electrodes, an outer container, a resin inner container in which the capacitive element is disposed and which is located between the capacitive element and the outer container, and a filling resin filled in the inner container and the outer container.

[0007] In order to solve the above problems, a method for manufacturing a capacitor according to the present invention includes the steps of forming a capacitive element with a pair of electrodes and a dielectric located between the pair of electrodes, housing the capacitive element in a resin inner container, housing the inner container in an outer container, filling the inner container and the outer container with a filling resin, and hardening the filling resin. Effect of the Invention

[0008] The position of the capacitance element in the capacitor can be fixed, and sufficient insulation performance can be ensured. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram showing a capacitor according to a first embodiment. [Diagram 2] 3A to 3C are model diagrams illustrating a manufacturing process for the capacitor according to the first embodiment. [Diagram 3] 10A to 10C are model diagrams showing a manufacturing process for a capacitor according to embodiment 2. [Figure 4] 11A to 11C are model diagrams showing a manufacturing process for a capacitor according to embodiment 3. [Diagram 5] 11A to 11C are model diagrams showing a manufacturing process for a capacitor according to embodiment 4. [Figure 6] FIG. 13 is a schematic diagram showing a capacitor according to a comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Comparative Example Prior to describing the embodiments, a comparative capacitor 100 will be described first. Fig. 6 is a schematic diagram showing a comparative capacitor 100. The capacitor 100 includes a capacitive element 10, a first resin 20 (coating resin), an outer container 30, and a second resin 40 (filling resin).

[0011] Capacitive element 10 is an element that functions as a capacitor. Capacitive element 10 is formed by forming metallikon electrodes 12 on both end surfaces of wound body 11 formed by winding a pair of metallized films, and external terminals 13 are attached to metallikon electrodes 12. Note that the metallized film is a dielectric film on which a metal is formed. Capacitive element 10 is not limited to being formed by winding a metallized film, and may be formed by stacking metallized films.

[0012] Metallikon electrode 12 is formed by spraying metal, and therefore is not densely packed with metal but is porous with many gaps. Therefore, oxygen and water vapor can enter wound body 11 through the gaps in metallikon electrode 12, causing degradation of the performance of capacitance element 10.

[0013] The first resin 20 is a resin that does not contain a filler. The first resin 20 is impregnated into the capacitive element 10, and the outer periphery of the capacitive element 10 is covered with the first resin. Since the first resin 20 does not contain a filler, the first resin 20 penetrates into the inside of the capacitive element 10 without leaving any gaps, and also fills the gaps in the metallikon electrode 12. This makes it possible to suppress the intrusion of oxygen, water vapor, and the like into the capacitive element 10. After the capacitive element 10 is covered with the first resin 20, it is cured. For example, the first resin 20 can be an epoxy resin.

[0014] The outer container 30 is a metal container with only one side open. The outer container 30 accommodates the capacitive element 10 covered with the first resin 20 inside. The outer container 30 is then filled with the second resin 40 and sealed to produce the capacitor 100.

[0015] Here, since the specific gravity of the capacitive element 10 covered with the first resin 20 is smaller than the specific gravity of the second resin 40, when the second resin 40 is being injected, the capacitive element 10 covered with the first resin 20 will float relative to the second resin 40.

[0016] Therefore, the position of the capacitance element 10 relative to the outer container 30 is not fixed, and in some cases, sufficient insulation performance may not be obtained. For example, the metallikon electrode 12 of the capacitance element 10 may come into contact with the outer container 30, causing a short circuit. In addition, since the capacitance element 10 has many cavities inside, it may have a lower specific gravity than the second resin 40. As a result, there is a high possibility that the capacitance element 10 will float when the second resin is being injected.

[0017] The second resin 40 contains a filler. Therefore, if sealing is performed using only the second resin 40 without the first resin 20, it is not possible to prevent oxygen, water vapor, and the like from entering the capacitive element 10. However, since the second resin 40 contains a filler, less heat is generated when the second resin 40 hardens, and the possibility of damaging the capacitive element 10 is low. An example of the second resin 40 is a urethane resin.

[0018] [Embodiment 1] Hereinafter, an embodiment according to one aspect of the present invention (hereinafter, also referred to as "the present embodiment") will be described with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference characters and their description will not be repeated.

[0019] (Capacitor 1 Overview) Next, a description will be given of the capacitor 1 according to the embodiment 1. Fig. 1 is a schematic diagram showing the capacitor 1 according to the embodiment 1. The capacitor 1 includes a capacitive element 10, a first resin 20, an outer container 30, a second resin 40, and an inner container 50.

[0020] The inner container 50 is a resin container with only one side open. The inner container 50 accommodates the capacitive element 10 covered with the first resin 20 in an uncured state. The first resin 20 is then cured. As a result, the inner container 50 and the capacitive element 10 are bonded together. In other words, there is a portion between the capacitive element 10 and the inner container 50 where only the first resin 20 exists, and the two are bonded together at this portion.

[0021] Thereafter, the inner container 50 combined with the capacitive element 10 is housed in the outer container 30, and the inner container 50 and the outer container 30 are filled with the second resin 40 and sealed, thereby producing the capacitor 1. In other words, the inner container 50 is a resin container in which the capacitive element 10 is disposed and which is located between the capacitive element 10 and the outer container 30.

[0022] That is, in capacitor 100, first resin 20 is cured only on capacitive element 10, whereas in capacitor 1, first resin 20 is cured so as to bond capacitive element 10 and inner container 50. Note that in capacitor 1, like capacitor 100, capacitive element 10 is covered with first resin 20, so that degradation of capacitive element 10 due to oxygen and water vapor can be prevented.

[0023] (Insulation for the capacitance element 10) In the capacitor 1, the capacitive element 10 is coupled to the inner container 50. Furthermore, since the capacitive element 10 is housed in the resin inner container 50, it is not in direct contact with the outer container 30. Therefore, it is easy to ensure the insulation of the capacitive element 10.

[0024] In addition, because the capacitive element 10 is bonded to the inner container 50, the position of the capacitive element 10 can be determined by placing the inner container 50 with respect to the outer container 30. Furthermore, because the sides of the inner container 50 are also covered with resin, it is easy to ensure a sufficient insulation distance for the capacitive element 10 even if the positioning of the capacitive element 10 is not performed precisely.

[0025] (Anti-oxidation and moisture resistance) The capacitive element 10 is covered with a first resin 20 that does not contain a filler, and this first resin 20 penetrates into the inside of the capacitive element 10. Therefore, there is no part of the capacitive element 10 that is in direct contact with air, and therefore it is possible to prevent the intrusion of oxygen and water vapor. In other words, there is an effect of preventing oxidation of the capacitive element 10 and improving its moisture resistance. Note that the capacitive element 10 is impregnated with the first resin 20 under a reduced pressure environment, whereby bubbles can be removed from within the capacitive element 10.

[0026] (Capacitor 1 manufacturing process) A description will now be given of the manufacturing process of the capacitor 1 according to embodiment 1. Fig. 2 is a model diagram showing the manufacturing process of the capacitor 1 according to embodiment 1.

[0027] First, the capacitive element 10 is constructed (step 61). Then, the capacitive element 10 is immersed in a liquid tank filled with the first resin 20 and pulled out, thereby covering the capacitive element 10 with the first resin 20 (step 62). The capacitive element 10 covered with the first resin 20 is housed in an inner container 50 (step 63). Then, the first resin 20 is cured together with the inner container 50 and the capacitive element 10, and the inner container 50 and the capacitive element 10 are bonded together (step 64).

[0028] The joined inner container 50 is placed in the outer container 30 (step 65). The second resin 40 is first poured into the inner container 50, but not into the outer container 30 (step 66). As the pouring of the second resin 40 continues, the inner container 50 becomes full, and the second resin 40 overflows from the upper edge of the inner container 50 and enters the outer container 30 (step 67).

[0029] The second resin 40 is being poured into the outer container 30, but since the inner container 50 is already filled to the brim with the second resin 40, the weight of the inner container 50 side is sufficiently heavy. At the height of the liquid surface of the second resin 40 in the outer container 30, the specific gravity of the inner container 50 side is sufficiently greater than the specific gravity of the second resin 40. Therefore, the inner container 50 combined with the capacitance element 10 does not float up relative to the outer container 30, and the second resin 40 can be poured to the end (step 68). The second resin 40 is then cured together with the outer container 30 (step 69), thereby manufacturing the capacitor 1.

[0030] [Embodiment 2] Other embodiments of the present invention will be described below. For ease of explanation, the same reference numerals are given to members having the same functions as those described in the above embodiment, and the description thereof will not be repeated.

[0031] The second embodiment differs from the first embodiment in the process of injecting the second resin 40 in the manufacturing process of the capacitor 1. Fig. 3 is a model diagram showing the manufacturing process of the capacitor 1 according to the second embodiment. In the manufacturing process of the capacitor 1 according to the second embodiment, steps 61 to 65 are the same as those in the first embodiment.

[0032] The second resin 40 is poured so that the liquid levels in the inner container 50 and the outer container 30 become the same (step 71). For example, the inner container 50 may have an opening or a cut through which the second resin 40 can move between the inner container 50 and the outer container 30, thereby balancing the liquid levels of both.

[0033] The second resin 40 continues to be poured until the liquid level reaches a specified height (step 72). At this time, the weight of the inner container 50 is sufficiently heavy that the inner container 50 and the capacitive element 10 do not float. Thereafter, the second resin 40 is cured together with the outer container 30 (step 73), thereby manufacturing the capacitor 1.

[0034] [Embodiment 3] Other embodiments of the present invention will be described below. For ease of explanation, the same reference numerals are given to members having the same functions as those described in the above embodiment, and the description thereof will not be repeated.

[0035] In the third embodiment, the process of injecting the second resin 40 in the manufacturing process of the capacitor 1 according to the first embodiment is different from that in the first embodiment. Fig. 4 is a model diagram showing the manufacturing process of the capacitor 1 according to the third embodiment. In the manufacturing process of the capacitor 1 according to the third embodiment, steps 61 to 64 are the same as those in the first embodiment.

[0036] After the inner container 50 and the capacitive element 10 are bonded together with the first resin, the bonded inner container 50 is housed in the outer container 30, and the inner container 50 and the outer container 30 are temporarily fixed together with clips 80 (step 81).

[0037] The second resin 40 is first poured into the outer container 30, but not into the inner container 50 (step 82). As the pouring of the second resin 40 continues, the liquid level in the outer container 30 becomes higher than the height of the upper edge of the inner container 50, and the second resin 40 enters the inner container 50 from the upper edge of the inner container 50 (step 83). At this time, since the inner container 50 and the outer container 30 are temporarily fixed by the clip 80, the inner container 50 and the capacitive element 10 will not float, regardless of the specific gravity of the inner container 50 side and the specific gravity of the second resin 40.

[0038] The injection of the second resin 40 is continued until the liquid level reaches a specified height (step 84). After that, the clip 80 is removed, and the second resin 40 is cured together with the outer container 30 (step 85), thereby manufacturing the capacitor 1.

[0039] In other embodiments, fixing inner container 50 and outer container 30 with clips 80 is also effective in preventing inner container 50 and capacitance element 10 from floating up. Therefore, the position of capacitance element 10 in capacitor 1 can be controlled with high precision, resulting in a capacitor with high insulation performance.

[0040] [Embodiment 4] Other embodiments of the present invention will be described below. For ease of explanation, the same reference numerals are given to members having the same functions as those described in the above embodiment, and the description thereof will not be repeated.

[0041] In embodiment 4, the timing of hardening of the first resin is different in the manufacturing process of capacitor 1 from embodiments 1 to 3. Fig. 5 is a model diagram showing the manufacturing process of capacitor 1 according to embodiment 4. In the manufacturing process of capacitor 1 according to embodiment 4, steps 61 to 63 are the same as those in embodiment 1.

[0042] A small amount of the first resin 20 is injected into the outer container 30, and then the inner container 50 housing the capacitive element 10 covered with the first resin 20 is housed in the outer container 30 (step 91). Then, the first resin 20 is cured for the outer container 30, the inner container 50 and the capacitive element 10, and the outer container 30, the inner container 50 and the capacitive element 10 are bonded together (step 92).

[0043] The second resin 40 is poured into the outer container 30 and / or the inner container 50 by the method of any one of the first to third embodiments (step 93). The pouring of the second resin 40 is continued until the liquid level reaches a specified height (step 94). At this time, since the outer container 30, the inner container 50, and the capacitive element 10 are bonded together by step 92, the capacitive element 10 does not float up.

[0044] Thereafter, the second resin 40 is cured together with the outer container 30 (step 95), thereby completing the manufacture of the capacitor 1.

[0045] [Modifications] In all of the first to third embodiments, the capacitor 1 is produced by two-step curing, that is, curing the first resin 20 and curing the second resin 40, but the number of curing steps may be increased. Specifically, the second resin 40 may be primarily cured at step 67 in the first embodiment, at step 71 in the second embodiment, and at step 82 in the third embodiment. In this case, even if clips 80 are not used and a light inner container 50 is used, it is possible to prevent the capacitive element 10 from floating up.

[0046] In the fourth embodiment, an inner bottom made of resin may be provided instead of the inner container 50. In this case, the inner bottom prevents contact between the capacitive element 10 and the bottom surface of the outer container 30, and the position of the capacitive element 10 relative to the outer container 30 is determined by bonding with the first resin. Therefore, unlike the inner container 50, it is not necessary to surround five sides of the capacitive element 10, and the inner bottom may cover only one side, the bottom surface.

[0047] 〔summary〕 The capacitor according to aspect 1 of the present invention comprises a capacitive element including a pair of electrodes and a dielectric located between the pair of electrodes, an outer container, a resin inner container in which the capacitive element is disposed and which is located between the capacitive element and the outer container, and a filling resin filled in the inner container and the outer container.

[0048] According to the above configuration, since the resin inner container is provided between the capacitance element and the outer container, sufficient insulation of the capacitance element can be ensured.

[0049] The capacitor according to a second aspect of the present invention may be configured in such a manner that, in the above-mentioned first aspect, the capacitor further includes a coating resin that covers the capacitive element and does not contain a filler.

[0050] According to the above-mentioned configuration, since the capacitance element is covered with the coating resin, it is possible to prevent oxygen and water vapor from entering the inside of the capacitor, and thus it is possible to prevent deterioration of the performance of the capacitor.

[0051] The capacitor according to a third aspect of the present invention may be configured in such a way that in the second aspect, there is a portion between the capacitive element and the inner container where only the coating resin is present.

[0052] According to the above-mentioned configuration, the capacitive element and the inner container are bonded together by the coating resin, which makes it possible to prevent the capacitive element from being displaced or lifted up due to injection of the filling resin.

[0053] A capacitor according to a fourth aspect of the present invention may be configured as in any one of the first to third aspects, in which the filling resin is a resin containing a filler.

[0054] According to the above-mentioned configuration, when a large amount of the filling resin needs to be cured, heat generation can be reduced, so that the capacitance element is not damaged.

[0055] A method for manufacturing a capacitor according to aspect 5 of the present invention includes the steps of forming a capacitive element with a pair of electrodes and a dielectric located between the pair of electrodes, housing the capacitive element in a resin inner container, housing the inner container in an outer container, filling the inner container and the outer container with a filling resin, and hardening the filling resin.

[0056] According to the above configuration, since the resin inner container is provided between the capacitance element and the outer container, sufficient insulation of the capacitance element can be ensured.

[0057] The method for producing a capacitor according to a sixth aspect of the present invention may further include, in addition to the fifth aspect, a step of coating the capacitive element with a coating resin that does not contain a filler before housing the capacitive element in the inner container.

[0058] According to the above configuration, since the capacitance element is covered with the coating resin, it is possible to prevent oxygen and water vapor from entering the inside of the capacitor, and thus it is possible to prevent deterioration of the performance of the capacitor.

[0059] The method for producing a capacitor according to a seventh aspect of the present invention may be the method for producing a capacitor according to the fifth or sixth aspect, further comprising the step of curing the coating resin after housing the capacitive element in the inner container.

[0060] According to the above-mentioned configuration, the capacitive element and the inner container are bonded together by the coating resin, which makes it possible to prevent the capacitive element from being displaced or lifted up due to injection of the filling resin.

[0061] [Additional Notes] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. [Explanation of symbols]

[0062] 1, 100 Capacitor 10 Capacitive element 11 Winding body 12 Metallicon electrode 13 External terminal 20 First resin (coating resin) 30 Outer packaging 40 Second resin (filler resin) 50 Inner packaging

Claims

1. A capacitor, A capacitive element including a pair of electrodes and a dielectric material located between the pair of electrodes; An outer container; an inner container made of resin, the inner container having the capacitive element disposed therein and positioned between the capacitive element and the outer container; and a filling resin filled in the inner container and the outer container.

2. The capacitor according to claim 1 , further comprising a coating resin that does not contain a filler and covers the capacitive element.

3. 3. The capacitor according to claim 2, wherein there is a portion between the capacitance element and the inner container where only the coating resin exists.

4. The capacitor according to claim 1 , wherein the filled resin is a resin containing a filler.

5. A method for manufacturing a capacitor, comprising the steps of: forming a capacitance element by a pair of electrodes and a dielectric material located on the pair of electrodes; a step of housing the capacitive element in an inner container made of resin; placing the inner container in an outer container; filling the inner container and the outer container with a filling resin; and curing the filled resin.

6. The method according to claim 5 , further comprising the step of covering the capacitive element with a coating resin that does not contain a filler before housing the capacitive element in the inner container.

7. The method according to claim 6 , further comprising the step of curing the coating resin after the capacitive element is housed in the inner container.

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