Capacitor and method for manufacturing the same

Abstract

To provide a capacitor that can be manufactured by a relatively simple method.SOLUTION: The capacitor includes: a capacitor element; an exterior case storing the capacitor element; one of cured rubber and curable resin fixing the capacitor element to the exterior case; and an exterior lid. The capacitor element is sealed in an inner space formed by the exterior case and the exterior lid joined to each other. One of the cured rubber and the curable resin covers the lower end part of the capacitor element. The electrode drawing part of the capacitor element faces the inner side wall of the exterior case.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a capacitor and a method for manufacturing the same. [Background technology]

[0002] 2. Description of the Related Art Conventionally, a capacitor has been known in which a capacitor element is sealed with an outer case and an outer lid, and the capacitor element is fixed in the outer case with resin or the like.

[0003] Patent Document 1 describes a capacitor element in which the lower electrode lead portion is covered and fixed with resin inside an outer case. This capacitor element is sealed by an outer case and an outer case lid, with one of the electrode lead portions facing the outer lid and the other facing the inner bottom surface of the outer case. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-110446 Summary of the Invention [Problem to be solved by the invention]

[0005] Conventional methods of sealing a capacitor element in an outer case can result in relatively poor physical properties and / or quality of the capacitor due to variations in the manufacturing process.

[0006] In this context, the present disclosure aims to provide a capacitor that can be manufactured by a relatively simple method, and also aims to provide a relatively simple method for manufacturing a capacitor. Furthermore, the present disclosure aims to provide a capacitor with improved quality through such a capacitor and manufacturing method. In particular, the present disclosure aims to provide a capacitor that is relatively easy to assemble, has reduced errors in the manufacturing process, and thus has relatively stable quality.

Means for Solving the Problem

[0007] The object of the present disclosure can be solved by the following aspects of the invention according to the present disclosure: <Aspect 1> A capacitor element, An exterior case for housing the capacitor element, A cured rubber or curable resin that fixes the capacitor element to the exterior case, and An exterior lid Comprising: The capacitor element is sealed within an internal space formed by the exterior case and the exterior lid joined to each other, The cured rubber or curable resin covers the lower end portion of the capacitor element, The electrode lead-out portion of the capacitor element is disposed to face the inner side wall of the exterior case, A capacitor. <Aspect 2> The capacitor according to Aspect 1, wherein the capacitor element is a thin film polymer laminated capacitor element. <Aspect 3> The capacitor according to Aspect 1 or Aspect 2, wherein the exterior case and the exterior lid are made of metal. <Aspect 4> The capacitor according to any one of Aspects 1 to 3, wherein the joining of the exterior lid and the exterior case is double winding. <Aspect 5> The capacitor according to any one of Aspects 1 to 4, wherein the internal space is vacuum or filled with an inert gas. <Aspect 6> The capacitor according to Aspect 5, wherein the inert gas is nitrogen gas, helium gas, or a mixed gas thereof. <Aspect 7> The capacitor according to any one of Aspects 1 to 6, wherein the rubber or curable resin does not release reaction gas during curing. <Aspect 8> The rubber or the curable resin contains at least one selected from RTV silicone rubber, epoxy resin, urethane resin, and diallyl phthalate resin, and the capacitor according to any one of Aspects 1 to 7. <Aspect 9> The height H in the internal space of the cured rubber or curable resin R is 10 to 50% of the height H of the internal space I and the capacitor according to any one of Aspects 1 to 8. <Aspect 10> The rubber or the curable resin adheres to at least a part of the inner side wall of the outer case and the inner wall of the outer lid, and the capacitor according to any one of Aspects 1 to 9. <Aspect 11> It has a connection member for electrically connecting the capacitor element to the outside, the connection member extends through the outer lid, one end portion of the connection member is connected to the capacitor element in the internal space, the other end portion of the connection member is disposed outside the capacitor, and the capacitor according to any one of Aspects 1 to 10. <Aspect 12> Among the connection members passing through the outer lid, the portion adjacent to the inner wall of the outer lid is covered with the rubber or the curable resin, and the capacitor according to Aspect 11. <Aspect 13> The connection member is composed of an integral member, and the capacitor according to Aspect 11 or Aspect 12. <Aspect 14> The connection member is composed of a plurality of members connected to each other. Among these plurality of members, at least the member connected to the capacitor element in the internal space is composed of an integral member, and the capacitor according to Aspect 11 or Aspect 12. <Aspect 15> The connection portion between the connection member and the capacitor element exists at the upper end portion of the capacitor element, and the capacitor according to any one of Aspects 11 to 14. <Aspect 16> The capacitor according to any one of Aspects 11 to 15, wherein the connecting member is made of a material with high rigidity. <Aspect 17> The capacitor according to any one of Aspects 1 to 16, which can be continuously used at 125°C. <Aspect 18> The capacitor according to any one of Aspects 1 to 17, which is a capacitor for use at a voltage of 200 V or higher. <Aspect 19> A method for manufacturing a capacitor, comprising: providing a capacitor element; providing an exterior case that contains uncured rubber or curable resin and has an opening; accommodating the capacitor element in the exterior case and covering a lower end portion of the capacitor element with the uncured rubber or the curable resin; arranging and joining an exterior lid so as to cover the opening of the exterior case to seal the exterior case; and curing the uncured rubber or the curable resin after sealing the exterior case. Including: When accommodating the capacitor element in the exterior case, the capacitor element is accommodated such that an electrode lead-out portion of the capacitor element faces an inner side wall of the exterior case. Method. <Aspect 20> The method according to Aspect 19, wherein the capacitor element is a thin-film polymer laminated capacitor element. <Aspect 21> The method for manufacturing a capacitor according to Aspect 19 or Aspect 20, wherein the exterior case and the exterior lid are made of metal, and the exterior lid and the exterior case are joined to each other by double winding. <Aspect 22> The method for manufacturing a capacitor according to any one of Aspects 19 to 21, wherein the exterior case is sealed under vacuum or filled with an inert gas and then sealed. <Aspect 23> When providing the capacitor element, provide the capacitor element pre-fixed to the exterior lid. Here, the capacitor element is fixed to the exterior lid by a connection member for electrically connecting the capacitor element to the outside, and the connection member extends through the exterior lid. The method according to any one of Aspects 19 to 22. <Aspect 24> After sealing the capacitor element and before curing the uncured rubber or curable resin, by rotating or inverting the exterior case, the uncured rubber or curable resin is adhered to the inner side wall of the exterior case and the inner wall of the exterior lid, and a portion of the connection member passing through the exterior lid and adjacent to the inner wall of the exterior lid is covered with the rubber or curable resin. The method according to Aspect 23.

Advantages of the Invention

[0008] According to the invention of the present disclosure, a capacitor that can be manufactured by a relatively simple method can be provided, and a relatively simple method for manufacturing a capacitor can also be provided. Furthermore, according to the present invention, a capacitor having improved quality can be provided by such a capacitor and manufacturing method. In particular, according to the invention of the present disclosure, a capacitor that is relatively easy to assemble, reduces errors in the manufacturing process, and thereby has relatively stable quality can be provided. Also, according to the invention of the present disclosure, cost advantages in mass production can be expected. Furthermore, in particular, according to the invention of the present disclosure, an increase in ESR or ESL may be suppressed.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Mode for Carrying Out the Invention

[0010] <<Capacitor>> The invention according to the present disclosure is a capacitor, which a capacitor element, an exterior case for housing the capacitor element, a cured rubber or curable resin that fixes the capacitor element to the exterior case, and an exterior lid and includes The capacitor element is sealed in an internal space formed by the exterior case and the exterior lid joined to each other, the cured rubber or curable resin covers the lower end portion of the capacitor element, and the electrode lead-out portion of the capacitor element is disposed to face the inner side wall of the exterior case.

[0011] As described above, in the conventional method of sealing the capacitor element in the exterior case, the physical properties and / or quality of the capacitor may be relatively inferior due to errors in the manufacturing process.

[0012] In the conventional fixing method, since one of the electrode lead-out portions was fixed with resin at the bottom of the exterior case, the connecting member (for example, a lead wire) for connecting the capacitor element and the external electrode was "asymmetric" with respect to the capacitor element. In this case, the manufacturing process becomes complicated, and problems such as an increase in ESR and / or ESL are relatively likely to occur.

[0013] In contrast, in the capacitor according to the present invention, the electrode lead-out portions of the capacitor element are arranged to face the inner side wall of the exterior case. In this case, symmetrical connection of the connection members becomes possible, thereby solving the above problems. That is, since the two electrode lead-out portions at both ends of the capacitor element can be brought close to the two terminal portions of the exterior lid, the assembly of the capacitor can be facilitated. Also, the connection members can be shortened, and it becomes easier to make the lengths of the two connection members the same. As a result, errors in the manufacturing process of the capacitor can be reduced, and furthermore, an increase in ESR or ESL can be suppressed, and cost advantages in mass production can be expected.

[0014] The capacitor of the present invention will be described with reference to the drawings. The drawings are illustrative and do not limit the present invention The drawings are not to scale.

[0015] FIG. 1 (Fig. 1) shows an example of a capacitor according to the present invention. The capacitor 10 according to the present invention includes a capacitor element 101, a cured rubber or curable resin 106, an exterior case 105 that houses the capacitor element 101, and an exterior lid 102. The exterior case 105 has an opening for inserting the capacitor element and the like into the exterior case 105 during the manufacture of the capacitor. This opening is covered and closed by the exterior lid 102.

[0016] The outer cover 102 is connected to the capacitor element 101 via two connecting members 103a and connecting member 103b. These connecting members are members for electrically connecting the capacitor element to the outside. The connecting member may be composed of a plurality of members. For example, it may be composed of a first member (so-called terminal portion) passing through the outer cover, and a second member (so-called lead) connecting the inner space side end portion of the first member and the capacitor element. In this case, at least the second member may be formed from an integral member. Alternatively, the connecting member may be formed from a single integrally molded member. The capacitor element 101 has electrode lead-out portions 104a and 104b, which face the inner side wall of the outer case 105. As can be seen in the figure, with such an arrangement, the configuration of the connecting member is symmetric, and the length of the connecting member is relatively short.

[0017] The capacitor element 101 is sealed in the internal space formed by the joining of the outer case 105 and the outer cover 102. The lower end portion of the capacitor element 101 adjacent to the bottom of the outer case is covered by a cured rubber or curable resin 106, whereby the capacitor element is fixed to the outer case. The height H of the cured rubber or curable resin 206 R may be 10 to 50% of the height H of the cavity of the outer case (or the height of the internal space formed later by the outer case and the outer cover), and may also be 20 to 40%. I

[0018] In FIG. 1, both the outer case 105 and the outer cover 102 are made of metal, and their joining is a double winding. The cured rubber or curable resin 106 fills only a part of the internal space of the capacitor. In the embodiment of FIG. 1, it covers about 1 / 4 of the height H of the internal space of the capacitor. The internal space of the capacitor in FIG. 1 is vacuum or filled with an inert gas. The shape of the outer case is not particularly limited, and may be, for example, cylindrical or prismatic (especially square prismatic). I

[0019] <<Method for Manufacturing a Capacitor>> The present disclosure also includes an invention of a method for manufacturing a capacitor, which provides a capacitor element, provides an exterior case that contains uncured rubber or curable resin and has an opening, houses the capacitor element in the exterior case, and covers the lower end portion of the capacitor element with uncured rubber or curable resin, places an exterior lid so as to cover the opening of the exterior case, and seals the exterior case by joining, and cures the uncured rubber or curable resin after sealing the exterior case, includes When housing the capacitor element in the exterior case, the capacitor element is housed such that the electrode lead-out portion of the capacitor element faces the inner side wall of the exterior case. This is the method.

[0020] By covering only the "lower end portion" of the capacitor element with uncured rubber or curable resin, the capacitor element is fixed to the exterior case. This enables weight reduction of the capacitor. In addition, since the amount of resin is reduced, problems caused by the resin (for example, generation of decomposition gas due to deterioration caused by the ambient temperature environment) can be reduced.

[0021] Also, in the manufacturing method of the present invention, when housing the capacitor element in the exterior case, the capacitor element is housed such that the electrode lead-out portion of the capacitor element faces the inner side wall of the exterior case. As a result, the distance between the electrode lead-out portion of the capacitor element and the terminal portion attached to the exterior lid becomes short and symmetrical, so that assembly becomes easy, and reduction of errors in the manufacturing process and improvement of quality thereby can be expected. In addition, it becomes possible to reduce the ESR and ESL of the capacitor.

[0022] Furthermore, in the manufacturing method of the present invention, since the rubber / resin curing treatment is performed after joining between the exterior case and the exterior lid, it is possible to prevent the load associated with this joining from being applied to the terminal portion (such as a connection member) of the capacitor.

[0023] Figure 2 (Fig. 2) shows an example of a method for manufacturing a capacitor according to the present invention. In the method of Figure 2, first, a capacitor element is provided (left side of (1) in the figure). The configuration according to the present invention in which the electrode lead-out portion is opposed to the inner side wall of the exterior case also enables the capacitor element to be relatively stably fixed to the exterior lid in advance. That is, in the embodiment of Figure 2, the provided capacitor element 201 is connected to the exterior lid 202 via the connection member 203a and the connection member 203b. By providing the capacitor element in a state of being connected to the exterior lid in advance in this way, the manufacture of the capacitor can be simplified and the manufacturing accuracy can be improved. The connection member 203a and the connection member 203b may be made of a highly rigid material, whereby the position of the capacitor element 201 with respect to the exterior lid 202 is fixed. This capacitor element 201 has an electrode lead-out portion 204a and an electrode lead-out portion 204b on two side main surfaces, respectively. The exterior lid 202 is made of metal.

[0024] In the method of Figure 2, also, an exterior case 205 containing uncured rubber or curable resin 206 is provided (right side of (1) in the figure). The height of the cured rubber or curable resin 206 may be 10 to 50% of the height of the cavity of the exterior case (or the height of the internal space formed later by the exterior case and the exterior lid), or may be 20 to 40%. The exterior case 205 is made of metal.

[0025] Then, in the method of Figure 2, the capacitor element 201 fixed to the exterior lid 202 is housed in the exterior case 205, and the lower end portion of the capacitor element 201 is covered with the uncured rubber or curable resin 206 (arrow in (1) of the figure). At the same time, the exterior lid is disposed on top of the opening side of the exterior case to cover the opening (Figure (2)).

[0026] And in the method of FIG. 2, the capacitor element 201 is sealed in the internal space by joining the exterior case 205 and the exterior lid 202 to each other (FIG. (3)), and then, the uncured rubber or curable resin 206 is cured to manufacture the capacitor 20 (step (4)). In FIG. 2, the joining of the exterior case 205 and the exterior lid 202 is performed by double winding. It is preferable that the uncured rubber or curable resin does not generate gas during curing. It is desirable that the internal space is in a vacuum (reduced pressure) state or filled with an inert gas.

[0027] According to such a method, a relatively simple method for manufacturing a capacitor is provided, whereby a capacitor having improved quality can be provided.

[0028] Hereinafter, each component of the present invention will be described in more detail.

[0029] <Capacitor Element> The capacitor of the present invention includes a capacitor element.

[0030] The capacitor element may be, for example, a film capacitor element or a thin-film polymer laminated capacitor element, and particularly may be a thin-film polymer laminated capacitor element or the like, but is not limited thereto.

[0031] <Thin-Film Polymer Laminated Capacitor Element> In one embodiment of the present invention, the capacitor element is a thin-film polymer laminated capacitor element using a thermosetting resin as a dielectric. A capacitor using a thin-film polymer laminated capacitor element is suitable for applications that require high heat resistance, such as in-vehicle applications and power electronics capacitor applications. The thin-film polymer laminated capacitor element has a structure in which a dielectric layer (resin thin-film layer) containing a thermosetting resin and an electrode layer (metal thin-film layer) containing a metal are alternately laminated. That is, since the thin-film polymer laminated capacitor is superior in heat resistance to a conventional film capacitor, it has the advantages that a resin with a high curing temperature can be used for the resin that fixes the element inside the exterior case, and that a high operating guarantee temperature can be obtained. By using a thin-film polymer laminated capacitor element as an internal element of the capacitor and making the exterior airtight, the environmental resistance can be greatly improved, and for example, a power film capacitor that can be continuously used and guaranteed at 150 to 200°C can be provided. According to this aspect, miniaturization and high reliability of the power film capacitor can be achieved.

[0032] The thin-film polymer laminated capacitor element has a structure in which a dielectric layer (resin thin-film layer) containing a thermosetting resin and an electrode layer (metal thin-film layer) containing a metal are alternately laminated.

[0033] FIG. 4 is a schematic perspective view of a thin-film polymer laminated capacitor 1. The thin-film polymer laminated capacitor 1 has a laminate 2 in which a resin thin-film layer and a metal thin-film layer (internal electrode metal layer) are alternately laminated, and two electrode lead-out portions 3 and 4 are attached to this laminate 2. In the figure, the dimensional directions of "width W", "height H", and "depth D" are shown.

[0034] (Dimensions of the capacitor element) The capacitor element can have a prismatic shape. In particular, a capacitor having a prismatic shape has a relatively large "depth D" with respect to the "width W" and "height H", and electrode lead-out portions are applied in a planar manner to two opposing side surfaces (see Fig. 4). Here, "relatively large" means that "depth D" has a length at least 1.5 times that of each of "width W" and "height H", preferably at least 2.0 times, more preferably at least 2.5 times the depth.

[0035] For example, a capacitor element according to one embodiment of the present invention has a width of 16 mm, a height of 30 mm, and a depth of 75 mm.

[0036] Details of the thin-film polymer laminated capacitor element will be described later. For specific examples of the thin-film polymer laminated capacitor element, reference can be made to, for example, International Publication No. 2015 / 118693.

[0037] <Film Capacitor Element> The film capacitor element is formed by laminating or winding a metallized film in which electrodes are formed by vapor-depositing a metal such as zinc or aluminum on a plastic film such as polypropylene. The film capacitor element includes electrode lead-out portions formed by spraying metal on both end faces thereof. The capacitor is constituted by a connecting member that electrically connects the electrode lead-out portions to the outside.

[0038] <Electrode Lead-Out Portion> The capacitor element includes electrode lead-out portions formed by spraying metal on both end faces thereof. The electrode lead-out portion may have, for example, a surface of tin metallicon.

[0039] In the present invention, the electrode lead-out portions of the capacitor element are arranged to face the inner side wall of the exterior case. In particular, both of the two electrode lead-out portions are arranged to face the inner side surface of the exterior case. In this case, for example, since both of the two electrode lead-out portions at both ends of the capacitor element can be brought close to the two terminal portions of the exterior lid, the assembly of the capacitor can be facilitated. Further, it becomes possible to shorten the connection members for external electrical connection of the capacitor element, and it also becomes easy to make the dimensions of the two connection members the same. Thereby, for example, it becomes possible to reduce the ESR and ESL of the capacitor.

[0040] <Exterior case> The capacitor of the present invention includes an exterior case. The exterior case has a function of housing the capacitor element, and has a cavity (hollow) for housing the capacitor element and an opening.

[0041] In one embodiment of the present invention, the exterior case is made of metal. In this case, for example, a capacitor having better heat resistance and moisture resistance can be provided as compared with the case of using an exterior case made of a plastic material.

[0042] The shape of the exterior case is not particularly limited, and for example, it may be cylindrical or prismatic (particularly a quadrangular prism). For example, the exterior case has a bottom surface and side surfaces, and these bottom surface and side surfaces define the above-mentioned cavity (hollow). Further, the exterior case may have an opening in a portion corresponding to the upper surface. Through this opening, the capacitor element can be housed in the cavity.

[0043] The cavity of the exterior case may have a size corresponding to the size of the capacitor element. For example, it may have a volume 1.5 to 3 times the volume of the capacitor element. Further, for example, the exterior case may have a diameter of 10 mm to 500 mm, 20 mm to 200 mm, or further 30 mm to 100 mm. Further, for example, the exterior case may have a height of 10 mm to 500 mm, 50 mm to 200 mm, or further 75 mm to 150 mm.

[0044] Also, the walls (particularly the side walls and the bottom wall) constituting the exterior case may have a thickness of, for example, 0.1 mm to 0.5 mm, 0.2 to 0.4 mm, or even 0.2 to 0.3 mm.

[0045] In one particularly preferred embodiment, the exterior case is a metal can, particularly a steel can or an aluminum can.

[0046] <Exterior lid> The capacitor of the present invention includes an exterior lid. The exterior lid can be joined to the exterior case (particularly the opening of the exterior case) to form a sealed space (internal space). By joining the exterior lid to the exterior case having the capacitor element housed in the cavity, the capacitor element can be sealed.

[0047] In one embodiment of the present invention, the exterior lid is made of metal. In this case, a capacitor with better heat resistance and moisture resistance can be provided as compared with the case of using an exterior lid made of, for example, a plastic material.

[0048] The shape of the exterior lid is not particularly limited, and may be, for example, disk-shaped or plate-shaped.

[0049] In one particularly preferred embodiment, the exterior lid is made of steel or aluminum.

[0050] When both the exterior lid and the exterior case are made of metal, the exterior case and the exterior lid can be sealed by double crimping, so that the environmental resistance of the capacitor can be further improved.

[0051] In one embodiment of the present invention, the joining of the exterior lid and the exterior case is double crimping. Thereby, airtightness can be maintained over a long period.

[0052] <Cured rubber or curable resin> The cured rubber or curable resin fixes the capacitor element to the exterior case.

[0053] In the capacitor of the present invention, the cured rubber or curable resin covers the lower end portion of the capacitor element.

[0054] Here, the "lower end portion" generally refers to the portion of the capacitor element disposed in the exterior case that is closer to the bottom surface side of the exterior case. In contrast, the "upper end portion" refers to the portion of the capacitor element disposed in the exterior case that is closer to the upper surface (particularly the opening) of the exterior case. Note that the portion of the capacitor element between the lower end portion and the upper end portion can be referred to as the "central portion".

[0055] For example, the capacitor element disposed in the exterior case can be divided into three portions along the direction from the bottom surface side to the upper surface side (particularly the opening side) of the exterior case, and from the bottom surface side, they can be respectively the "lower end portion", the "central portion", and the "upper end portion". In this case, with respect to the height of the capacitor element along the direction from the bottom surface side to the upper surface side (particularly the opening side), the "lower end portion" can have a height such that it is covered by the rubber or curable resin, for example, a height such that at least 5% of the capacitor element is covered by the rubber or curable resin. This height of the "lower end portion" can be more preferably 5 to 40% of the total height of the capacitor element, particularly preferably 10 to 30%. The size (particularly the height) of the lower end portion covered by the cured rubber or curable resin can be determined according to the amount of rubber or curable resin required for fixing the capacitor element and the size of the desired internal space, etc.

[0056] Similarly, the "upper end portion" of the capacitor element can be at least 5% of the total height of the capacitor element along the direction from the bottom surface side to the upper surface side (particularly the opening side). The "upper end portion" can be more preferably 10% to 30% of the total height of the capacitor element, particularly preferably 20% to 30%. The connecting member can be connected to the upper end portion or the central portion of the capacitor element.

[0057] In one embodiment of the present invention, the rubber or curable resin does not release reaction gas during curing. In this case, when curing is performed after sealing the capacitor inside the outer case, gas is not released into the internal space of the capacitor, so airtightness can be maintained and deformation of the outer case can be prevented.

[0058] In one embodiment of the present invention, the rubber or curable resin contains at least one selected from RTV silicone rubber, epoxy resin, urethane resin, and diallyl phthalate resin. RTV silicone rubber not only does not release reaction gas during curing, but also has excellent thermal conductivity and flame retardancy, and can promote heat dissipation. In addition, due to its rubbery properties, it adheres to the uneven shape, and the effects of absorbing shock and promoting heat dissipation can be obtained.

[0059] In one embodiment of the present invention, the rubber or curable resin adheres not only to the bottom of the outer case, but also to the inner side wall of the outer case and the inner wall of the outer lid. This leads to more stable joining of the outer lid and the outer case, improved airtightness, and protection of the inner wall.

[0060] <Internal space> According to the capacitor of the present invention, the capacitor element is sealed in the internal space formed by the outer case and the outer lid joined to each other.

[0061] In one embodiment of the present invention, the internal space in the outer case is vacuum or filled with an inert gas. Thereby, the capacitor can be protected from moisture and heat. In addition, since there is almost no oxygen in the internal space, oxidative degradation and thermal oxidative degradation of the capacitor element (dielectric resin) and the rubber or cured resin for fixing can be prevented. Preferably, it is filled with an inert gas having high thermal conductivity, thereby promoting heat dissipation of the capacitor heated by current superposition. Examples of the inert gas include nitrogen gas, helium gas, or a mixed gas thereof. Helium gas, or a mixed gas of helium gas and nitrogen gas, is preferable because it has a particularly high thermal conductivity among inert gases.

[0062] In one embodiment of the present invention, the height H of the cured rubber or curable resin in the internal space R is the height of the internal space H I The ratio is 10 to 50%, more preferably 20 to 40%. In this case, the amount of resin present in the internal space is reduced, so problems caused by the resin (for example, generation of decomposition gas due to deterioration in the ambient temperature environment) can be reduced or even avoided. In addition, the weight of the capacitor can be reduced. Since weight reduction of parts is important particularly for in-vehicle applications, reducing the weight of the capacitor can increase added value.

[0063] The "height" of the internal space is generally equal to the height of the interior (i.e., cavity) of the outer case. For example, the "height" of the internal space is equal to the height from the inner surface of the bottom of the outer case to the opening of the outer case (or the inner wall surface of the outer lid).

[0064] <Connection parts> In one embodiment of the present invention, the capacitor has a connection member for electrically connecting the capacitor element to the outside, the connection member extending through the exterior lid, one end of the connection member connected to the capacitor element, and the other end of the connection member disposed outside the capacitor.

[0065] In one embodiment of the present invention, the connecting member is configured from an integral member, which is advantageous in terms of strength reliability, manufacturing cost and tact time.

[0066] In another embodiment of the present invention, the connecting member is composed of a plurality of members, and among these plurality of members, at least the member connected to the capacitor element is composed of an integral member. This embodiment is relatively advantageous in terms of strength reliability, and is also relatively advantageous in terms of manufacturing cost and tact. In this embodiment, for example, the connecting member has a first connecting member (for example, a terminal portion) and a second connecting member (for example, a lead portion), the first connecting member penetrates the outer lid and has two end portions protruding in opposite directions from the outer lid, and the second connecting member is a member that connects the inner space side end portion of the first connecting member and the capacitor element.

[0067] In one embodiment of the present invention, the portion of the connecting member adjacent to the inner wall of the outer lid (so-called "root" portion) is covered with rubber or a curable resin. This embodiment is advantageous in terms of enhancing (reinforcing) strength. This can be realized, for example, by rotating or inverting the outer case after sealing the thin film polymer laminated capacitor element and before curing the uncured rubber or curable resin, thereby attaching the uncured rubber or curable resin to the root portion.

[0068] In one embodiment of the present invention, the connecting member is made of a highly rigid material (rigid material). As a result, since the capacitor element is fixed to the outer lid by leads, the connection between the outer lid and the capacitor element becomes easy during the manufacturing process, and stability within the outer case is obtained. Also, by using a rigid material, the positional relationship between the outer lid and the capacitor element can be determined in advance before the capacitor element is housed in the outer case, so that errors between products are reduced and quality improvement can be expected. Note that "highly rigid" particularly means having a rigidity that enables the positional relationship between the outer lid and the connecting member to remain immovable during the manufacturing process of the capacitor when the outer lid is fixed to the capacitor element via the connecting member. A person skilled in the art can appropriately select a material and / or size that satisfies this condition.

[0069] The connecting member may be made of, for example, copper, nickel, aluminum, or their alloys, and may be a metal wire, a rod-shaped metal member, or a metal plate. For connection to the element, the element-side end of the connecting member that is a metal wire or a rod-shaped metal member may have a flat shape. For example, gold plating or the like may be applied on the surface of the connecting member to enhance solderability. Plating that melts during soldering (such as tin plating) has a low degree of preference from the viewpoint of maintaining good airtightness at the joint between the lid and the lead.

[0070] In one particularly preferred embodiment, the connecting member is a metal lead, and in particular, a copper lead. The lead may have a diameter of, for example, 0.5 mm to 5.0 mm.

[0071] In one embodiment of the present invention, the capacitor has two connecting members respectively connected to two electrode lead-out portions of the capacitor element, and the connection portions between these two connecting members and the capacitor element are both present outside the cured rubber or curable resin. As a result, since the amount of resin does not cover the entire element, weight reduction of the capacitor can be achieved.

[0072] In one embodiment of the present invention, the connection portion between the connecting member and the capacitor element is present at the upper end portion of the capacitor element. As a result, since two relatively short connecting members of the same length are prepared, the structure is simplified, and the labor and cost of providing the leads can be reduced.

[0073] The method of joining the connecting member (particularly the terminal portion of the connecting member) and the exterior lid (particularly a steel lid or an aluminum lid) is not particularly limited, and may be, for example, a hermetic seal (airtight seal), particularly a glass seal.

[0074] In the hermetic seal, specifically, for example, the space between the terminal portion made of aluminum or copper inserted into the opening provided in the exterior lid and the exterior lid is filled with glass and sealed. For example, glass sealing by the GTAS (registered trademark) technology of SCHOTT can be mentioned.

[0075] <Use of the capacitor> In one embodiment of the present invention, the capacitor according to the present invention can be continuously used at 125°C. Here, "continuously usable" means that when continuously used for at least 1000 hours, there is no substantial deterioration in the performance (particularly capacitance) of the capacitor. "Substantial deterioration" particularly means that the reduction rate of the performance (particularly capacitance) of the capacitor is less than 10%, less than 5%, particularly less than 2%.

[0076] In one embodiment of the present invention, the capacitor according to the present invention is for in-vehicle use.

[0077] In one embodiment of the present invention, the capacitor according to the present invention can be used at a voltage of 200V or more.

[0078] In one embodiment of the present invention, the capacitor according to the present invention is a capacitor for power electronics.

[0079] <<Manufacturing method of the capacitor>> The manufacturing method of the capacitor according to the present disclosure is not particularly limited. The capacitor according to the present disclosure can be manufactured, for example, by the following manufacturing method of the capacitor according to the present disclosure.

[0080] The manufacturing method of the capacitor of the present invention is providing a capacitor element (capacitor element providing step), providing an exterior case that contains uncured rubber or curable resin and has an opening (exterior case providing step), placing the capacitor element in the exterior case and covering the lower end portion of the capacitor element with uncured rubber or curable resin (accommodating step), placing an exterior lid so as to cover the opening of the exterior case and joining it to seal the exterior case (sealing step), and after sealing the exterior case, curing the uncured rubber or curable resin (curing step), and includes When housing the capacitor element in the exterior case, the capacitor element is housed such that the electrode lead-out portion of the capacitor element faces the inner side wall of the exterior case. This is the method.

[0081] Regarding each component (for example, capacitor element, exterior case, exterior lid, rubber or curable resin, etc.) in the method for manufacturing a capacitor according to the present disclosure, the above description regarding the capacitor according to the present disclosure can be referred to.

[0082] <Capacitor Element Providing Step> The method for manufacturing a capacitor of the present invention includes providing a capacitor element.

[0083] The capacitor element may be a film capacitor element or a thin-film polymer laminated capacitor element, particularly a thin-film polymer laminated capacitor element, but is not limited thereto.

[0084] In one embodiment of the present invention, a thin-film polymer laminated capacitor element is provided. As described above, since the thin-film polymer laminated capacitor is superior in heat resistance to a conventional film capacitor, there are advantages that a resin with a high curing temperature may be used for the resin that fixes the element inside the exterior case, and that a high operation guarantee temperature can be obtained.

[0085] The thin-film polymer laminated capacitor element will be described later. For specific examples of the thin-film polymer laminated capacitor element, for example, International Publication No. 2015 / 118693 can be referred to.

[0086] In one embodiment of the present invention, when providing the capacitor element, a capacitor element fixed to the exterior lid is provided. Thereby, the connection between the exterior lid and the capacitor element becomes easy. Further, before housing the capacitor element in the exterior case, the positional relationship between the exterior lid and the capacitor element can be determined in advance, so that the positioning error is reduced and quality improvement can be expected.

[0087] In one embodiment of the present invention, a capacitor element is fixed to an exterior lid by a connection member for electrically connecting the capacitor element to the outside.

[0088] In one embodiment of the present invention, the connection portion between the connection member and the capacitor element is present at the upper end portion of the capacitor element. As a result, since two relatively short connection members of the same length are prepared, the structure is simplified, and the labor and cost of providing the connection members can be reduced.

[0089] <Exterior case providing step> The manufacturing method of the present invention includes providing an exterior case containing uncured rubber or curable resin.

[0090] In one embodiment of the present invention, the rubber or curable resin does not emit reaction gas during curing. In this case, when curing is performed after sealing the capacitor in the exterior case, gas is not released into the internal space of the capacitor, so airtightness can be maintained and deformation of the exterior case can be prevented.

[0091] In one embodiment of the present invention, at least one selected from the group consisting of RTV silicone rubber, epoxy resin, urethane resin, and diallyl phthalate resin is used as the rubber or curable resin. RTV silicone rubber not only does not emit reaction gas during curing, but also has excellent thermal conductivity and flame retardancy, and can promote heat dissipation. In addition, due to its rubber properties, it adheres to the uneven shape, and the effects of absorbing impact and promoting heat dissipation can be obtained.

[0092] In one embodiment of the present invention, the exterior case is made of metal. In this case, for example, a capacitor with better heat resistance and moisture resistance can be provided compared to the case of using an exterior case made of a plastic material.

[0093] The uncured rubber or curable resin accommodated in the exterior case may fill the interior of the exterior case at a height such that the cured rubber or curable resin occupies 10% to 50% of the height of the cavity of the exterior case (or the internal space of the capacitor) in the completed capacitor, and particularly may fill the interior of the exterior case at a height such that it occupies 20% to 40%.

[0094] <Storage step> The manufacturing method of the present invention includes housing a capacitor element in an exterior case and covering the lower end portion of the capacitor element with uncured rubber or curable resin.

[0095] In this step, for example, the capacitor element is inserted into the cavity of the exterior case through the opening of the exterior case, and in this way, the lower end portion of the capacitor element is immersed in the uncured rubber or curable resin disposed at the bottom of the exterior case. At this time, by appropriately conforming the capacitor element to the uncured rubber or curable resin, the generation of air bubbles can be avoided.

[0096] The method of the present disclosure is characterized in that when housing the capacitor element in the exterior case, the capacitor element is housed such that the electrode lead-out portion of the capacitor element faces the inner side wall of the exterior case.

[0097] As a result, the distance between the electrode lead-out portion of the capacitor element and the terminal portion attached to the exterior lid becomes shorter and symmetrical, so that assembly becomes easier, and reduction of errors in the manufacturing process and thereby improvement in quality can be expected. Also, it becomes possible to reduce the ESR and ESL of the capacitor.

[0098] <Sealing step> The manufacturing method of the present invention includes sealing the exterior case by disposing and joining an exterior lid so as to cover the opening of the exterior case.

[0099] In one embodiment of the present invention, the exterior lid is made of metal. In this case, a capacitor with better heat resistance and moisture resistance can be provided as compared with the case of using an exterior lid made of, for example, a plastic material.

[0100] When the exterior lid and the exterior case are made of metal, the exterior case and the exterior lid can be sealed by double caulking, so that the environmental resistance of the capacitor can be further improved.

[0101] In one embodiment of the present invention, the joining of the exterior lid and the exterior case is double caulking. Thereby, airtightness can be maintained over a long period of time.

[0102] In one embodiment of the present invention, the exterior case is sealed under vacuum (or reduced pressure) or filled with an inert gas and then sealed. Thereby, the capacitor can be protected from moisture and heat. Further, since there is almost no oxygen in the internal space, oxidative degradation and thermal oxidative degradation of the capacitor element (dielectric resin) and the rubber or cured resin for fixing can be prevented. Preferably, it is filled with an inert gas having high thermal conductivity, thereby promoting heat dissipation.

[0103] Examples of the inert gas include nitrogen gas, helium gas, or a mixed gas thereof. Helium gas or a mixed gas of helium gas and nitrogen gas is preferable because it has a particularly high thermal conductivity among inert gases.

[0104] <Curing step> The manufacturing method of the present invention includes curing an uncured rubber or curable resin after sealing the exterior case.

[0105] The curing conditions of the rubber or curable resin are not particularly limited and can be appropriately determined according to the type and / or amount, etc. For example, when RTV silicone rubber is used as the rubber or curable resin, the curing of the rubber or curable resin can be carried out at a temperature of 80 to 120°C for 30 minutes to 3 hours.

[0106] In one embodiment of the present invention, after sealing the capacitor element and before curing the uncured rubber or curable resin, the outer case is rotated or inverted to attach the uncured rubber or curable resin to the inner side wall of the outer case and the inner wall of the outer lid. This leads to more stable joining of the outer lid and the outer case, improved sealing performance, and protection of the inner wall and the internal space.

[0107] In one embodiment of the present invention, after sealing the capacitor element and before curing the uncured rubber or curable resin, the outer case is rotated or inverted to cover the portion of the connecting member adjacent to the inner wall of the outer lid (so-called "root" portion) with rubber or curable resin. This embodiment is advantageous in terms of enhancing (reinforcing) the strength of the physical or electrical connection by the connecting member.

[0108] (Thin film polymer multilayer capacitor element) The thin film polymer multilayer capacitor element has a structure in which a dielectric layer containing resin (resin thin film layer) and an electrode layer containing metal (metal thin film layer) are alternately laminated.

[0109] For example, the thin film polymer multilayer capacitor element can be manufactured by the following method: (1) A step of forming a monomer layer by vapor-depositing a monomer in a vacuum chamber and then irradiating the monomer layer with an electron beam to cure the monomer layer to form a resin thin film layer; (2) A step of forming a metal thin film layer by vapor-depositing a metal material; (3) A step of manufacturing a laminate in which a resin thin film layer and a metal thin film layer are alternately laminated on a rotating drum by alternately repeating the process on the rotating drum.

[0110] When forming the resin thin film layer, as the monomer, for example, a dimethacrylate compound having an alicyclic hydrocarbon skeleton can be used to form a monomer layer.

[0111] The thin film polymer multilayer capacitor may have 10 to 10,000 layers, 50 to 5,000 layers, or 100 to 2,000 layers.

[0112] The dielectric layer containing resin is often formed using a monomer having an acrylic group or a methacrylic group or the like. Examples of such monomers include dicyclopentadiene methanol diacrylate, tricyclodecane dimethanol diacrylate, and tricyclodecane dimethanol dimethacrylate.

[0113] In a particularly preferred embodiment, the dielectric layer containing resin has a polymer structure formed by polymerizing a first monomer which is a monofunctional monomer, a second monomer which is a bifunctional monomer, and a third monomer which is a polyfunctional monomer having trifunctionality or higher. Here, the first monomer may include 2-(biphenyl-2-yloxy)-ethyl acrylate, 4-phenylbenzyl acrylate, stearyl acrylate, or stearyl methacrylate; the second monomer may include tricyclodecane dimethanol diacrylate or tricyclodecane dimethanol dimethacrylate; and / or the third monomer may include triallyl isocyanurate.

[0114] The dielectric layer containing resin may have a thickness of 10 nm to 3000 nm, preferably 100 to 1500 nm.

[0115] Examples of the metal material constituting the electrode layer containing metal include at least one selected from the group consisting of Al, Cu, Zn, Sn, Au, Ag, Pt, and combinations thereof. The metal material constituting the metal thin film layer is preferably aluminum.

[0116] The electrode layer containing metal may have a thickness of 1 nm to 100 nm, preferably 10 to 40 nm. Also, the metal thin film layer preferably has a deposition resistance value of 1 to 50 Ω / sq, 5 to 40 Ω / sq, or 5 to 30 Ω / sq.

[0117] Preferably, the thin-film polymer laminated capacitor has a relative dielectric constant of 2.0 or more when measured at 25°C and 1 kHz. This relative dielectric constant is more preferably 2.1 or more, 2.2 or more, 2.3 or more, or 2.5 or more. The upper limit of this relative dielectric constant is not particularly limited, but it may be 5.0 or less.

[0118] The relative dielectric constant at 25°C and 1 kHz can be calculated based on the capacitance measured using an LCR meter, as well as the electrode area and the thickness of the dielectric.

[0119] Also preferably, the thin-film polymer laminated capacitor has a tanδ (also referred to as dielectric tangent or loss factor) of less than 1.0% when measured at 25°C and 1 kHz. This tanδ is more preferably 0.9% or less, 0.85% or less, 0.8% or less, 0.7% or less, 0.6% or less, 0.5% or less, 0.4% or less, 0.3% or less, 0.2% or less, or 0.1% or less. The lower limit of this tanδ is not particularly limited, but it may be 0.05% or more.

[0120] The tanδ at 25°C and 1 kHz can be measured using an LCR meter.

[0121] Furthermore, preferably, the thin-film polymer laminated capacitor has a tanδ of less than 2.0% when measured at 105°C and 1 kHz. This tanδ is more preferably 1.5% or less, and even more preferably 1.2% or less. The lower limit of this tanδ is not particularly limited, but it may be 0.1% or more.

[0122] The tanδ at 105°C and 1 kHz can be measured using an LCR meter.

[0123] Preferably, the thin-film polymer laminated capacitor exhibits a water absorption rate of 0.2 to 0.9%. This water absorption rate is particularly 0.25 to 0.80%, more particularly 0.30 to 0.70%. This water absorption rate can be measured by the following method: Place the capacitor with the electrode lead-out part cut off in a thermo-hygrostat chamber at a temperature of 60 °C and a relative humidity of 90%, conduct a moisture absorption test by leaving it stationary for 100 hours, and then measure the weight change rate (%) of the capacitor, and use this as the water absorption rate (%) of the capacitor: Weight change rate (%) = 100×(weight after moisture absorption test - weight before moisture absorption test) / weight before moisture absorption test.

Example

[0124] <<Example 1 and Comparative Example 1>> In Example 1 and Comparative Example 1, capacitors were fabricated and their physical properties were evaluated.

[0125] <Example 1> The capacitor specifications and exterior specifications of the fabricated capacitors are summarized in Table 1.

Table 1

[0126] The manufacturing procedure of the capacitor according to the example includes the following: (1) A connecting member integrated with the exterior lid is joined to the electrode lead-out part (surface tin metallization) of the capacitor element by welding (the tip of the connecting member at the welded part is pre-compressed and thinly widened). (2) Put RTV rubber into the exterior case. (3) Under a reduced-pressure environment, the capacitor element and the exterior lid are housed in the exterior case. (4) The exterior lid and the exterior case are joined by double winding and hermetically sealed. (5) Heat-cure the RTV rubber at 100 °C for 1.5 hours.

[0127] The capacitor element used was a thin-film polymer multilayer capacitor element. This capacitor element had a rectangular parallelepiped shape with a relatively long depth D, and two opposite side surfaces (surfaces extending in the depth and height directions) of this rectangular parallelepiped each had an electrode lead-out portion.

[0128] As described in the above manufacturing procedure, before housing the capacitor element in the exterior case, the capacitor element was fixed to the exterior lid in advance via a connecting member. Since the exterior lid was connected to the capacitor element by connecting members extending symmetrically from the two side surfaces of the capacitor element, the resulting composite of the exterior lid and the capacitor element was shape-stable and could be easily handled during the manufacturing process.

[0129] In the manufacturing process of the capacitor according to the embodiment, when housing the capacitor element in the exterior case, the capacitor element was housed such that the two electrode lead-out portions of the capacitor element faced the inner side walls of the exterior case respectively.

[0130] In the completed capacitor, since the electrode lead-out portions of the capacitor element faced the inner side walls of the exterior case, the two connecting members (lead wires) could have the same length and were arranged symmetrically with respect to the capacitor. Furthermore, since the connection portions between the two connecting members and the capacitor element were located at the upper end portion of the capacitor, the length of the connecting members themselves was relatively short. As a result, the capacitor characteristics (ESR and / or ESL) could be reduced and the strength reliability could also be improved.

[0131] Also, according to the method of facing each other as described above, there is an advantage that the capacitor element can be stably fixed to the exterior lid via a connecting member in advance, thereby simplifying the manufacturing process.

[0132] Figure 3 shows the results of the moisture resistance life test for an example of the capacitor according to the present invention and its comparative example. The moisture resistance life test was carried out by applying a voltage of 850 V under the conditions of a temperature of 85°C and a relative humidity (RH) of 85%. This experiment was conducted 5 times, and in Figure 3, the averages thereof are plotted. The plots of black circles represent the results of the examples, and the plots of black triangles represent the comparative examples. The vertical axis represents the capacitance change rate, and the horizontal axis represents the elapsed time (unit: hours).

[0133] In Figure 3, in Comparative Example 1, the capacitance disappeared after 250 hours, while in Example 1, there was almost no performance degradation even after the moisture resistance life test over 5000 hours, indicating very excellent environmental resistance.

Claims

1. A capacitor element, an exterior case for housing the capacitor element, a cured rubber or curable resin that fixes the capacitor element to the exterior case, and an exterior lid are provided, the capacitor element is sealed within an internal space formed by the exterior case and the exterior lid joined to each other, the cured rubber or curable resin covers a lower end portion of the capacitor element, an electrode lead-out portion of the capacitor element is disposed to face an inner side wall of the exterior case, a capacitor.

2. The capacitor according to claim 1, wherein the capacitor element is a thin-film polymer laminated capacitor element.

3. The capacitor according to claim 1 or claim 2, wherein the exterior case and the exterior lid are made of metal.

4. The capacitor according to claim 1 or claim 2, wherein the joining of the exterior lid and the exterior case is double crimping.

5. The capacitor according to claim 1 or claim 2, wherein the internal space is vacuum or filled with an inert gas.

6. The capacitor according to claim 5, wherein the inert gas is nitrogen gas, helium gas, or a mixed gas thereof.

7. The capacitor according to claim 1 or claim 2, wherein the rubber or curable resin does not emit reaction gas during curing.

8. The capacitor according to claim 1 or claim 2, wherein the rubber or curable resin contains at least one selected from RTV silicone rubber, epoxy resin, urethane resin, and diallyl phthalate resin.

9. The height H in the internal space of the cured rubber or the curable resin Ｒ is 10 to 50% of the height H of the internal space I of the capacitor according to claim 1 or claim 2.

10. The capacitor according to claim 1 or claim 2, wherein the rubber or curable resin adheres to at least a part of an inner side wall of the exterior case and an inner wall of the exterior lid.

11. It has a connection member for electrically connecting the capacitor element to the outside, the connection member extends through the exterior lid, one end portion of the connection member is connected to the capacitor element in the internal space, the other end portion of the connection member is disposed outside the capacitor, the capacitor according to claim 1 or claim 2.

12. the rubber or curable resin adheres to at least a part of an inner side wall of the exterior case and an inner wall of the exterior lid, and The capacitor according to claim 11, wherein a portion of the connecting member that penetrates the outer cover and is adjacent to the inner wall of the outer cover is covered with the rubber or the curable resin.

13. The capacitor according to claim 11, wherein the connecting member is composed of an integral member.

14. The capacitor according to claim 11, wherein the connecting member is composed of a plurality of members connected to each other, and at least a member among these plurality of members that is connected to the capacitor element in the internal space is composed of an integral member.

15. The capacitor according to claim 11, wherein a connection portion between the connecting member and the capacitor element exists at an upper end portion of the capacitor element.

16. The capacitor according to claim 11, wherein the connecting member is made of a material with high rigidity.

17. The capacitor according to claim 1 or claim 2, which can be continuously used at 125°C.

18. The capacitor according to claim 1 or claim 2, which is a capacitor for use at a voltage of 200 V or higher.

19. A method for manufacturing a capacitor, comprising: providing a capacitor element; providing an outer case that contains uncured rubber or curable resin and has an opening; accommodating the capacitor element in the outer case and covering a lower end portion of the capacitor element with the uncured rubber or the curable resin; arranging and joining an outer cover so as to cover the opening of the outer case to seal the outer case; and curing the uncured rubber or the curable resin after sealing the outer case. including When accommodating the capacitor element in the outer case, the capacitor element is accommodated such that an electrode lead-out portion of the capacitor element faces an inner side wall of the outer case. method

20. The method according to claim 19, wherein the capacitor element is a thin-film polymer laminated capacitor element.

21. The method according to claim 19 or claim 20, wherein the outer case and the outer cover are made of metal, and the outer cover and the outer case are joined to each other by double winding.

22. The method according to claim 19 or claim 20, wherein the outer case is sealed under vacuum or filled with an inert gas and then sealed.

23. When providing the capacitor element, provide the capacitor element pre-fixed to the exterior lid. Here, the capacitor element is fixed to the exterior lid by a connection member for electrically connecting the capacitor element to the outside, and the connection member extends through the exterior lid. The method according to claim 19 or claim 20.

24. After sealing the capacitor element and before curing the uncured rubber or curable resin, by rotating or inverting the exterior case, the uncured rubber or curable resin is adhered to the inner side wall of the exterior case and the inner wall of the exterior lid, and a portion of the connection member passing through the exterior lid and adjacent to the inner wall of the exterior lid is covered with the rubber or curable resin. The method according to claim 23.

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