Capacitor

Abstract

A capacitor 1 is equipped with: a capacitor element 10 which includes an element main body 11 and an external electrode 12 provided on an end surface of the element main body 11; a drawn terminal 20 which is electrically connected to the external electrode 12; an outer case 30 for storing the capacitor element 10 therein in a manner such that the drawn terminal 20 projects toward the outside; and a filling resin 40 which fills the interval between the capacitor element 10 and the outer case 30. The outer case 30 is a floor-equipped cylinder which has an opening 31 on one end thereof, and includes a floor wall 32 which seals the other end thereof and is opposite the opening 31, and a lateral wall 33 which projects toward the opening 31 from the floor wall 32. The inner surface of the outer case 30 is provided with a guide groove 34 for restricting the position of the drawn terminal 20. The guide groove 34 protrudes from the lateral wall 33 and extends from the opening 31 side toward the floor wall 32 side. The height of the guide groove 34 located on the opening 31 side of the outer case 30 is lower than the height of the lateral wall 33 located on the opening 31 side of the outer case 30 in the first mode. The corners of the sides of the guide groove 34 located on the opening 31 side of the outer case 30 are beveled in the second mode.

Description

capacitor

[0001] The present invention relates to a capacitor.

[0002] 2. Description of the Related Art A known type of capacitor is a film capacitor, which has a structure in which a flexible resin film is used as a dielectric film and metal layers are arranged facing each other with the dielectric film sandwiched therebetween.

[0003] Film capacitors are generally manufactured by the following method. First, a laminate is produced by winding or laminating a metallized film, which has a metal layer provided on the surface of a dielectric film, and then external electrodes (also called metallikon electrodes) are formed on both end surfaces of the laminate to produce a capacitor element. Next, lead terminals such as lead wires or bus bars are attached to the outer surfaces of the external electrodes. The capacitor element with the attached lead terminals is then housed in an exterior case such as a resin case, and the case is filled with resin and allowed to harden.

[0004] Patent Documents 1 and 2 describe that in order to prevent the capacitor element from tilting in the resin case, guide grooves are provided in the resin case to position the lead-out terminals.

[0005] JP-A-3-167813 JP-A-8-64468

[0006] Patent Document 1 does not describe the shape of the guide groove. On the other hand, Patent Document 2 shows two types of cross-sectional shapes of the guide groove, but does not describe the shape of the guide groove in detail.

[0007] However, when inserting the capacitor element into the outer case while aligning the lead terminals, such as lead wires, along the guide grooves of the outer case, the lead terminals may rub against the edges of the guide grooves and be damaged.

[0008] An object of the present invention is to provide a capacitor whose lead terminals are less likely to be damaged when the capacitor element is inserted into an outer case while aligning the lead terminals with guide grooves in the outer case.

[0009] The capacitor of the present invention comprises a capacitor element including an element body and an external electrode provided on an end surface of the element body, a lead terminal electrically connected to the external electrode, an outer case in which the capacitor element is housed so that the lead terminal protrudes outward, and a filling resin filled between the capacitor element and the outer case. The outer case is cylindrical with a bottom and has an opening at one end, a bottom wall facing the opening and sealing the other end, and a side wall protruding from the bottom wall toward the opening. A guide groove is provided on the inner surface of the outer case to regulate the position of the lead terminal. The guide groove protrudes from the side wall and extends from the opening side toward the bottom wall.

[0010] In a first aspect, the height of the guide groove located on the opening side of the outer case is lower than the height of the side wall located on the opening side of the outer case.

[0011] In a second aspect, the corners of the sides of the guide groove located on the opening side of the exterior case are chamfered.

[0012] According to the present invention, it is possible to provide a capacitor in which the lead-out terminals are less likely to be damaged when the capacitor element is inserted into the outer case while aligning the lead-out terminals with the guide grooves of the outer case.

[0013] FIG. 1 is a perspective view schematically showing a capacitor according to an embodiment of the present invention. FIG. 2 is a perspective view schematically showing an example of a state before a capacitor element constituting the capacitor shown in FIG. 1 is housed in an outer case. FIG. 3 is a perspective view schematically showing another example of a state before a capacitor element constituting the capacitor shown in FIG. 1 is housed in an outer case. FIG. 4 is a perspective view schematically showing guide grooves of an outer case according to a comparative example outside the scope of the present invention. FIG. 5 is a perspective view schematically showing a state in which a lead wire is arranged as a draw-out terminal in the guide groove of the outer case shown in FIG. 4. FIG. 6 is a perspective view schematically showing guide grooves of an outer case according to Example 1 within the scope of the present invention. FIG. 7 is a perspective view schematically showing a state in which a lead wire is arranged as a draw-out terminal in the guide groove of the outer case shown in FIG. 6. FIG. 8 is a side view of the outer case shown in FIG. 6. FIG. 9 is a plan view of the state shown in FIG. 7. FIG. 10 is a perspective view schematically showing guide grooves of an outer case according to Example 2 within the scope of the present invention. FIG. 11 is a perspective view schematically illustrating a state in which lead wires are arranged as lead terminals along the guide grooves of the outer case shown in FIG. 10. FIG. 12 is a side view of the outer case shown in FIG. 10. FIG. 13 is a plan view of the state shown in FIG. 11. FIGS. 14A, 14B, 14C, 14D, and 14E are side views showing modified shapes between the sidewall located on the opening side of the outer case and the guide groove. FIGS. 15A, 15B, 15C, 15D, 15E, and 15F are plan views showing modified shapes of the sides of the guide groove located on the opening side of the outer case. FIG. 16 is a perspective view schematically illustrating an example of a capacitor element constituting a capacitor of the present invention. FIG. 17 is a cross-sectional view of the capacitor element shown in FIG. 16 taken along line b-b. FIG. 18 is a perspective view schematically illustrating an example of an element body constituting the capacitor element shown in FIGS. 16 and 17. FIG. 19 is a perspective view schematically showing another example of the element body constituting the capacitor element shown in FIGS. 16 and 17. In FIG.

[0014] The capacitor of the present invention will be described below. Note that the present invention is not limited to the following configurations and may be modified as appropriate within the scope of the present invention. In addition, a combination of multiple individual preferred configurations described below also constitutes the present invention.

[0015] In this specification, terms indicating the relationship between elements (e.g., "perpendicular," "parallel," "orthogonal," etc.) and terms indicating the shape of elements are not expressions that only express a strict meaning, but are expressions that also include a range of substantial equivalence, for example, a difference of about a few percent.

[0016] As an embodiment of the capacitor of the present invention, a film capacitor will be described below, but the capacitor of the present invention can also be applied to capacitors other than film capacitors.

[0017] The drawings shown below are schematic diagrams, and the dimensions, aspect ratio, scale, etc. may differ from those of the actual product.

[0018] Fig. 1 is a perspective view schematically showing a capacitor according to an embodiment of the present invention. Fig. 2 is a perspective view schematically showing an example of a state before a capacitor element constituting the capacitor shown in Fig. 1 is housed in an outer case. Fig. 3 is a perspective view schematically showing another example of a state before a capacitor element constituting the capacitor shown in Fig. 1 is housed in an outer case.

[0019] The capacitor 1 shown in FIG. 1 includes a capacitor element 10 (see FIGS. 2 and 3), a lead terminal 20, an outer case 30, and a filling resin 40.

[0020] 2 and 3, the capacitor element 10 includes an element body 11 and external electrodes 12 provided on end surfaces of the element body 11. Specifically, a pair of external electrodes 12 is provided on both end surfaces of the element body 11.

[0021] The lead-out terminals 20 are electrically connected to the external electrodes 12. Specifically, a pair of lead-out terminals 20 are electrically connected to each of the pair of external electrodes 12.

[0022] Examples of the extraction terminal 20 include a lead wire and a bus bar. When the extraction terminal 20 is a lead wire, the lead wire may or may not have a plating layer on the surface.

[0023] Before being housed in the outer case 30, the pair of lead-out terminals 20 may extend from the external electrode 12 so that the distance between them is constant, as shown in Fig. 2, or may extend from the external electrode 12 so that the distance between them is greater, as shown in Fig. 3. On the other hand, after being housed in the outer case 30, it is preferable that the distance between the pair of lead-out terminals 20 is constant, as shown in Fig. 1.

[0024] As shown in FIGS. 1, 2 and 3, capacitor element 10 is housed inside outer case 30 so that lead-out terminals 20 protrude outward.

[0025] The exterior case 30 may be, for example, a resin case or a metal case.

[0026] 2 and 3, a rectangular parallelepiped space is formed inside the exterior case 30. Although not shown in FIGS. 2 and 3, the capacitor element 10 is preferably disposed in the center of the interior of the exterior case 30 while being spaced apart from the inner surface of the exterior case 30.

[0027] Filled resin 40 is filled between capacitor element 10 and exterior case 30. Specifically, filled resin 40 is filled between the outer surface of capacitor element 10 and the inner surface of exterior case 30. Capacitor element 10 is held inside exterior case 30 by filled resin 40.

[0028] The filling resin 40 fills the interior of the outer case 30 from the opening 31 of the outer case 30 (see FIGS. 2 and 3) to the capacitor element 10 .

[0029] The filling resin 40 may be, for example, an epoxy resin, etc. The epoxy resin can bond and fix the exterior case 30 and the capacitor element 10 together by heating and curing.

[0030] The outer case 30 is a cylindrical shape with a bottom and an opening 31 at one end. The outer case 30 includes a bottom wall 32 that faces the opening 31 and closes the other end, and a side wall 33 that protrudes from the bottom wall 32 toward the opening 31.

[0031] 2 and 3, the exterior case 30 has a generally rectangular opening 31 at one end, a bottom wall 32 that faces the opening 31 and seals the other end, and a square cylindrical side wall 33 that protrudes from the bottom wall 32 toward the opening 31. Note that instead of the square cylindrical side wall 33, the exterior case 30 may have a shape such as a bottomed cylindrical shape that includes a cylindrical side wall 33.

[0032] 2 and 3, the side wall 33 of the exterior case 30 preferably has a recess 33a on the edge facing the opening 31. By providing the recess 33a on the opening surface of the exterior case 30, when a capacitor such as a film capacitor is mounted on a board, the capacitor and the board are sealed, preventing an increase in internal pressure. Note that the exterior case 30 does not necessarily have to have the recess 33a.

[0033] 2 and 3, a guide groove 34 for regulating the position of the lead-out terminal 20 is provided on the inner surface of the exterior case 30. The guide groove 34 protrudes from the side wall 33 and extends from the opening 31 side to the bottom wall 32 side.

[0034] Fig. 4 is a perspective view showing a guide groove of an outer case according to a comparative example outside the scope of the present invention, and Fig. 5 is a perspective view showing a state in which a lead wire is placed as a lead terminal along the guide groove of the outer case shown in Fig. 4.

[0035] As shown in Figures 4 and 5 , when a capacitor element (not shown) is inserted into the outer case 30 by inserting the lead terminal 20 such as a lead wire into the outer case 30 while aligning it with the guide groove 34 of the outer case 30, the lead terminal 20 may rub against the edge of the guide groove 34 (side X of the guide groove 34 located on the opening 31 side of the outer case 30 in Figure 4 ), which may result in damage to the lead terminal 20.

[0036] Furthermore, not only will the lead-out terminal 20 be scratched, but the lead-out terminal 20 may rub against the edge of the guide groove 34 (side X of the guide groove 34 located on the opening 31 side of the outer case 30 in FIG. 4 ), which may generate metal chips from the surface of the lead-out terminal 20. In this case, problems such as metal chips flying out of the outer case 30 and adhering to the periphery of the capacitor, or the influence of the flying metal chips reducing the insulation of the outer surface of the capacitor may easily occur.

[0037] Fig. 6 is a perspective view schematically showing guide grooves of an outer case according to Example 1 within the scope of the present invention. Fig. 7 is a perspective view schematically showing a state in which lead wires are arranged as lead terminals along the guide grooves of the outer case shown in Fig. 6. Fig. 8 is a side view of the outer case shown in Fig. 6. Fig. 9 is a plan view of the state shown in Fig. 7.

[0038] The first feature of the outer case 30 shown in Figure 6 is that the height of the guide groove 34 located on the opening 31 side of the outer case 30 is lower than the height of the side wall 33 located on the opening 31 side of the outer case 30.

[0039] Specifically, the edge of the guide groove 34 located on the opening 31 side of the outer case 30 (side X of the guide groove 34 located on the opening 31 side of the outer case 30 in FIGS. 8 and 9 ) is located lower than the edge of the side wall 33 located on the opening 31 side of the outer case 30. By making the height of the edge of the guide groove 34 located on the opening 31 side of the outer case 30 (side X of the guide groove 34 located on the opening 31 side of the outer case 30 in FIGS. 8 and 9 ) lower than the height of the edge of the side wall 33 located on the opening 31 side of the outer case 30, it is possible to reduce the number of places where the lead terminals 20, such as lead wires, rub against the edge of the guide groove 34. Therefore, when a capacitor element (not shown) is inserted into the outer case 30 while aligning the lead terminals 20 along the guide grooves 34 of the outer case 30, the lead terminals 20 are less likely to be damaged.

[0040] Furthermore, by lowering the height of the edge of the guide groove 34 located on the opening 31 side of the exterior case 30 below the height of the edge of the side wall 33, even if the lead-out terminal 20 is scratched, it is possible to prevent metal chips generated from the surface of the lead-out terminal 20 from flying out to the outside of the exterior case 30. This makes it possible to prevent metal chips from adhering to the periphery of the capacitor and also to prevent creeping discharge from occurring on the surface of the capacitor.

[0041] Furthermore, a second feature of the exterior case 30 shown in FIG. 6 is that the corner of the side X (see FIGS. 8 and 9) of the guide groove 34 located on the opening 31 side of the exterior case 30 is chamfered.

[0042] When inserting a capacitor element (not shown) into the outer case 30 while aligning the lead terminal 20 such as a lead wire along the guide groove 34 of the outer case 30, the lead terminal 20 is likely to come into contact with the side X of the guide groove 34 located on the opening 31 side of the outer case 30. Therefore, by chamfering the corner of the side X of the guide groove 34 located on the opening 31 side of the outer case 30, the lead terminal 20 is less likely to be scratched.

[0043] The corner of the side X of the guide groove 34 located on the opening 31 side of the exterior case 30 is preferably rounded.

[0044] The corners of the guide groove 34 may also be chamfered on the sides other than the side X of the guide groove 34 located on the opening 31 side of the exterior case 30. In this case, it is preferable that the corners of the sides are rounded.

[0045] For example, if the draw-out terminal 20 is a lead wire having a plating layer on its surface, when the draw-out terminal 20 rubs against the edge of the guide groove 34, the plating layer is scraped off from the surface of the lead wire, easily generating metal chips. The rubbing force of the lead wire increases as the lead wire becomes thicker, so for example, if the outer diameter of the lead wire is 1 mm or more, metal chips are more likely to be generated. Even in such a case, the first or second feature makes the draw-out terminal 20 less susceptible to scratches.

[0046] The exterior case 30 shown in FIG. 6 has both the first and second features, but it may have only the first feature or only the second feature.

[0047] In the exterior case 30 shown in Fig. 6, as shown in Fig. 8, a step surface is provided between the guide groove 34 and the side wall 33 located on the opening 31 side of the exterior case 30. Furthermore, as shown in Fig. 9, when the guide groove 34 is viewed from the opening 31 side of the exterior case 30, the planar shape of the side X of the guide groove 34 located on the opening 31 side of the exterior case 30 is V-shaped.

[0048] As shown in Figures 6 and 8, the height difference between the side wall 33 located on the opening 31 side of the exterior case 30 and the guide groove 34 (the length indicated by H in Figures 6 and 8) is, for example, 2 mm.

[0049] As shown in FIGS. 8 and 9, the width of the guide groove 34 extending from the side wall 33 (the length indicated by W in FIGS. 8 and 9) is, for example, 0.8 mm.

[0050] Fig. 10 is a perspective view schematically showing guide grooves of an outer case according to Example 2 within the scope of the present invention. Fig. 11 is a perspective view schematically showing a state in which lead wires are arranged as lead terminals along the guide grooves of the outer case shown in Fig. 10. Fig. 12 is a side view of the outer case shown in Fig. 10. Fig. 13 is a plan view of the state shown in Fig. 11.

[0051] The first feature of the outer case 30 shown in Figure 10 is that the height of the guide groove 34 located on the opening 31 side of the outer case 30 is lower than the height of the side wall 33 located on the opening 31 side of the outer case 30.

[0052] Furthermore, a second feature of the exterior case 30 shown in FIG. 10 is that the corner of the side X of the guide groove 34 located on the opening 31 side of the exterior case 30 is chamfered.

[0053] The exterior case 30 shown in FIG. 10 also provides the same effects as the exterior case 30 shown in FIG.

[0054] The exterior case 30 shown in FIG. 10 has both the first and second features, but it may have only the first feature or only the second feature.

[0055] 12, in the exterior case 30 shown in Fig. 10, a flat inclined surface is provided between the guide groove 34 and the side wall 33 located on the opening 31 side of the exterior case 30. Furthermore, as shown in Fig. 13, when the guide groove 34 is viewed from the opening 31 side of the exterior case 30, the planar shape of the side X of the guide groove 34 located on the opening 31 side of the exterior case 30 is V-shaped.

[0056] As shown in Figures 10 and 12, the height difference between the side wall 33 located on the opening 31 side of the outer case 30 and the guide groove 34 (the length indicated by H in Figures 10 and 12) is, for example, 2 mm.

[0057] As shown in FIGS. 12 and 13, the width of the guide groove 34 extending from the side wall 33 (the length indicated by W in FIGS. 12 and 13) is, for example, 0.8 mm.

[0058] 14A, 14B, 14C, 14D, and 14E are side views showing modified shapes between the guide groove and the side wall located on the opening side of the outer case.

[0059] 14A , a stepped surface is provided between the guide groove 34 and the side wall 33 located on the opening 31 side of the outer case 30. The stepped surface effectively prevents metal chips generated from the surface of the lead-out terminal from flying out of the outer case 30. Note that a stepped surface with two or more steps may be provided between the guide groove 34 and the side wall 33 located on the opening 31 side of the outer case 30.

[0060] 14B , a flat inclined surface is provided between the guide groove 34 and the side wall 33 located on the opening 31 side of the outer case 30. The flat inclined surface ensures the guide function of the pull-out terminal while preventing metal chips generated from the surface of the pull-out terminal from flying out of the outer case 30. Note that two or more inclined surfaces may be provided between the guide groove 34 and the side wall 33 located on the opening 31 side of the outer case 30.

[0061] 14C, 14D, and 14E, a curved inclined surface is provided between the guide groove 34 and the side wall 33 located on the opening 31 side of the outer case 30. Like the flat inclined surface, the curved inclined surface ensures the guide function of the pull-out terminal while preventing metal chips generated from the surface of the pull-out terminal from flying out of the outer case 30.

[0062] The curved inclined surface may be convex toward the bottom wall 32 (not shown) of the outer case 30, as shown in Fig. 14C, or may be convex toward the opening 31 of the outer case 30, as shown in Fig. 14D. When an inclined surface that is convex toward the opening 31 of the outer case 30 is provided as shown in Fig. 14D, the corners of the sides of the guide groove 34 located on the opening 31 side of the outer case 30 are rounded, making it less likely that the pull-out terminals will be scratched.

[0063] 14E , the apex of the inclined surface that is convex toward the opening 31 of the outer case 30 may be between the guide groove 34 and the side wall 33 that is located on the opening 31 side of the outer case 30. Although not shown, the apex of the inclined surface that is convex toward the bottom wall 32 of the outer case 30 may also be between the guide groove 34 and the side wall 33 that is located on the opening 31 side of the outer case 30.

[0064] 15A, 15B, 15C, 15D, 15E, and 15F are plan views showing modified examples of the planar shape of the sides of the guide groove located on the opening side of the exterior case.

[0065] 15A and 15B , when the guide groove 34 is viewed from the opening 31 side of the exterior case 30, the side of the guide groove 34 located on the opening 31 side of the exterior case 30 has a V-shape in plan view. As shown in Figures 15A and 15B , the range in which the guide groove 34 is provided is not particularly limited.

[0066] 15C and 15D , when the guide groove 34 is viewed from the opening 31 side of the exterior case 30, the planar shape of the side of the guide groove 34 located on the opening 31 side of the exterior case 30 is a semicircular arc or a semi-elliptical arc. As shown in Figures 15C and 15D , the range in which the guide groove 34 is provided is not particularly limited.

[0067] 15E and 15F , when the guide groove 34 is viewed from the opening 31 side of the exterior case 30, the planar shape of the side of the guide groove 34 located on the opening 31 side of the exterior case 30 is an angular U-shape. As shown in Figures 15E and 15F , the range in which the guide groove 34 is provided is not particularly limited.

[0068] From the viewpoint of reducing the number of points where the lead terminals 20 such as lead wires come into contact with the guide grooves 34, it is preferable that the planar shape of the sides of the guide grooves 34 located on the opening 31 side of the outer case 30 be V-shaped as shown in Figures 15A and 15B.

[0069] In the capacitor of the present invention, the height difference between the side wall located on the opening side of the outer case and the guide groove is preferably 1 mm or more. If the height difference is 1 mm or more, metal chips generated from the surface of the lead terminal are less likely to fly out of the outer case. On the other hand, the height difference between the side wall located on the opening side of the outer case and the guide groove is preferably 5 mm or less. If the height difference is 5 mm or less, the lead terminal can easily be guided.

[0070] The size of the outer case varies depending on the required product specifications, but if the difference in height between the side wall located on the opening side of the outer case and the guide groove is within the above range, it is preferable that the height of the outer case be 1.5 cm or more.

[0071] In the capacitor of the present invention, the exterior case may be a resin case or a metal case.

[0072] When the exterior case is a resin case, the resin case preferably contains a liquid crystal polymer (LCP).

[0073] The liquid crystal polymer contained in the resin case may be, for example, a liquid crystal polymer having p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid groups in its skeleton. Liquid crystal polymers formed as polycondensates using various components other than p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid groups, such as phenol, phthalic acid, and ethylene terephthalate, may also be used. Liquid crystal polymers are also classified into types I, II, and III, but these types refer to the same material as the liquid crystal polymers formed from the above components.

[0074] The resin case preferably further contains an inorganic filler in addition to the liquid crystal polymer.

[0075] The inorganic filler contained in the resin case can be a material having a higher strength than the liquid crystal polymer. The inorganic filler is preferably a material having a higher melting point than the liquid crystal polymer, and more preferably a material having a melting point of 680°C or higher.

[0076] The shape of the inorganic filler is not particularly limited, and examples thereof include those having a longitudinal shape such as a fiber shape or a plate shape. Two or more of these inorganic fillers may be used in combination. Therefore, it is preferable that the resin case contains a fibrous inorganic material and / or a plate-like inorganic material as the inorganic filler.

[0077] In this specification, "fibrous" means that the relationship between the longitudinal length of the filler and the cross-sectional diameter in a cross section perpendicular to the longitudinal direction is longitudinal length ÷ cross-sectional diameter ≧ 5 (i.e., aspect ratio is 5:1 or more). Here, the cross-sectional diameter is the distance between the longest two points on the periphery of the cross section. When the cross-sectional diameter varies in the longitudinal direction, the measurement is performed at the point where the cross-sectional diameter is maximum. Furthermore, "plate-like" means that the relationship between the cross-sectional diameter of the surface with the largest projected area and the maximum height in the direction perpendicular to this cross section is cross-sectional diameter ÷ height ≧ 3.

[0078] It is preferable that the inorganic filler has at least a portion oriented in the side wall of the outer case from the bottom wall toward the opening and a portion oriented toward the adjacent side wall, and is dispersed inside the outer case.

[0079] The inorganic filler preferably has a diameter of at least 5 μm and a length of at least 50 μm. In particular, the inorganic filler is preferably dispersed throughout the outer case without agglomerating.

[0080] Specific examples of inorganic fillers that can be used include fibrous glass filler, plate-like talc, mica, etc. In particular, it is preferable that the inorganic filler contains glass filler as a main component.

[0081] When the exterior case is a resin case, the resin case may contain polyphenylene sulfide (PPS) instead of the liquid crystal polymer.

[0082] The resin case preferably further contains an inorganic filler in addition to polyphenylene sulfide.

[0083] As the inorganic filler contained in the resin case, the same materials as those used in the liquid crystal polymer can be used.

[0084] The resin case can be manufactured by a method such as injection molding.

[0085] When the exterior case is a metal case, the metal case is made of a metal such as aluminum, magnesium, iron, stainless steel, or copper, or an alloy containing at least one of these metals. Among these, the metal case is preferably made of aluminum or an aluminum alloy.

[0086] The metal case can be manufactured by a method such as impact molding.

[0087] In the capacitor of the present invention, the filler resin can be appropriately selected depending on the required function. Examples of the filler resin include epoxy resin, silicone resin, and urethane resin. An amine curing agent, an imidazole curing agent, or the like may be used as a curing agent for the epoxy resin. Alternatively, the filler resin may be a resin alone, or a reinforcing agent may be added to improve strength. Examples of the reinforcing agent include inorganic fillers such as silica and alumina, organic fillers such as polyethylene fibers and polyamide fibers, and organic-inorganic composite fillers in which the surface of an inorganic powder is coated with an organic material such as a silane coupling agent.

[0088] By filling the gap between the capacitor element and the exterior case with a filling resin, the capacitor element can be isolated from the outside air. For this reason, it is preferable to select a resin with low moisture permeability and to make the resin thicker at the opening of the exterior case.

[0089] The thickness of the resin at the opening of the outer case is preferably sufficient within the allowable range for the volume (physical size) of the entire capacitor, and specifically, is preferably 2 mm or more, and more preferably 4 mm or more. In particular, it is more preferable to arrange the capacitor element inside the outer case so that it is located closer to the bottom wall than to the opening of the outer case, so that the thickness of the resin on the opening side of the outer case relative to the capacitor element is thicker than the thickness of the resin on the bottom wall side.

[0090] The relationship between the height of the filled resin and the height of the outer case is such that the resin at the opening of the outer case is as thick as possible, and it may be up to a position on the inside of the outer case, or just to the point where it is level, or it may overflow slightly due to surface tension.

[0091] When the capacitor of the present invention is a film capacitor, the element body constituting the capacitor element is a laminate including a metallized film having a metal layer provided on at least one main surface of a dielectric film, and the external electrodes constituting the capacitor element are connected to the metal layer.

[0092] The laminate is, for example, in the form of a column with an elliptical cross section, and external electrodes formed by, for example, metal spraying (metallicon) are provided on both end faces in the direction of the central axis.

[0093] The laminate may be a roll in which the metallized film is rolled up in a laminated state.

[0094] Hereinafter, as an example of a film capacitor, a wound film capacitor in which a metallized film is wound in a laminated state will be described, but a laminated film capacitor in which a metallized film is laminated may also be used.

[0095] Fig. 16 is a perspective view schematically showing an example of a capacitor element constituting a capacitor of the present invention, and Fig. 17 is a cross-sectional view of the capacitor element shown in Fig. 16 taken along line bb.

[0096] 16 and 17 , element body 11 is a laminate including first metallized film 51 and second metallized film 52. For example, element body 11 is a wound body in which first metallized film 51 and second metallized film 52 are wound in a stacked state. A pair of external electrodes 12 are electrically connected to both end surfaces of element body 11.

[0097] As shown in Figure 17, the first metallized film 51 comprises a first dielectric film 53 and a first metal layer 55 provided on the surface of the first dielectric film 53, and the second metallized film 52 comprises a second dielectric film 54 and a second metal layer 56 provided on the surface of the second dielectric film 54.

[0098] 17 , the first metal layer 55 and the second metal layer 56 face each other with the first dielectric film 53 or the second dielectric film 54 sandwiched therebetween. Furthermore, the first metal layer 55 is electrically connected to one of the external electrodes 12, and the second metal layer 56 is electrically connected to the other external electrode 12.

[0099] The first dielectric film 53 and the second dielectric film 54 may have different configurations, but preferably have the same configuration.

[0100] The first metal layer 55 is formed on one surface of the first dielectric film 53 so as to reach one edge but not the other edge. On the other hand, the second metal layer 56 is formed on one surface of the second dielectric film 54 so as to not reach one edge but to reach the other edge. The first metal layer 55 and the second metal layer 56 are made of, for example, an aluminum layer.

[0101] FIG. 18 is a perspective view schematically showing an example of an element body constituting the capacitor element shown in FIGS. 16 and 17. In FIG.

[0102] 17 and 18, the first dielectric film 53 and the second dielectric film 54 are laminated with a shift relative to each other in the width direction (the left-right direction in FIG. 17) so that the end of the first metal layer 55 that reaches the side edge of the first dielectric film 53 and the end of the second metal layer 56 that reaches the side edge of the second dielectric film 54 are both exposed from the laminated films. As shown in FIG. 18, the element body 11 becomes a roll of metallized films by winding the first dielectric film 53 and the second dielectric film 54 in a laminated state, and is stacked with the first metal layer 55 and the second metal layer 56 exposed at their ends.

[0103] In Figures 17 and 18, the second dielectric film 54 is wound so that it is on the outside of the first dielectric film 53, and the first metal layer 55 and the second metal layer 56 of each of the first dielectric film 53 and the second dielectric film 54 are wound so that they face inward.

[0104] FIG. 19 is a perspective view schematically showing another example of the element body constituting the capacitor element shown in FIGS. 16 and 17. In FIG.

[0105] When element body 11 of the capacitor element is made of a wound body of metallized film, it is preferable that the cross section be pressed into a flattened shape such as an ellipse or oval, which is more compact than a true circle, as shown in Figure 19. In this case, by reducing the dead space inside the outer case, the outer case can be made smaller, and therefore the entire film capacitor can be made smaller.

[0106] The roll of the metallized film may include a cylindrical winding shaft that is disposed on the central axis of the rolled metallized film and serves as the winding shaft when the metallized film is wound.

[0107] The external electrodes 12 are formed by thermally spraying, for example, zinc onto each end face of the element body 11 obtained as described above. One external electrode 12 contacts an exposed end of the first metal layer 55, thereby being electrically connected to the first metal layer 55. The other external electrode 12 contacts an exposed end of the second metal layer 56, thereby being electrically connected to the second metal layer 56.

[0108] When the capacitor of the present invention is a film capacitor, the dielectric film constituting the element body of the capacitor element may contain a curable resin as a main component, or may contain a thermoplastic resin as a main component. From the viewpoint of improving the heat resistance of the film capacitor, it is preferable that the dielectric film contains a curable resin as a main component.

[0109] In this specification, the term "major component of the dielectric film" refers to the component with the largest weight percentage, preferably the component with a weight percentage of more than 50 wt %. Therefore, the dielectric film may contain components other than the major component, such as additives such as silicone resin, and uncured portions of starting materials such as the first organic material and second organic material described below.

[0110] The curable resin may be a thermosetting resin or a photocurable resin.

[0111] In this specification, thermosetting resin means a resin that can be cured by heat, and the curing method is not limited. Therefore, as long as it is a resin that can be cured by heat, resins that are cured by methods other than heat (for example, light, electron beam, etc.) are also included in thermosetting resins. Furthermore, depending on the material, a reaction may be initiated due to the reactivity of the material itself, and resins that proceed to cure without necessarily applying heat or light from the outside are also considered thermosetting resins. The same applies to photocurable resins, and the curing method is not limited.

[0112] The curable resin may or may not have at least one of a urethane bond and a urea bond. Examples of such resins include a urethane resin having a urethane bond and a urea resin having a urea bond. Alternatively, the curable resin may be a resin having both a urethane bond and a urea bond.

[0113] The presence of urethane bonds and / or urea bonds can be confirmed using a Fourier transform infrared spectrophotometer (FT-IR).

[0114] The curable resin is preferably a cured product of a first organic material and a second organic material, such as a cured product obtained by reacting a hydroxyl group (OH group) of the first organic material with an isocyanate group (NCO group) of the second organic material.

[0115] When a cured product is obtained by the above reaction, uncured portions of the starting material may remain in the film. For example, the dielectric film may contain at least one of an isocyanate group and a hydroxyl group. In this case, the dielectric film may contain either an isocyanate group or a hydroxyl group, or may contain both an isocyanate group and a hydroxyl group.

[0116] The presence of an isocyanate group and / or a hydroxyl group can be confirmed using a Fourier transform infrared spectrophotometer (FT-IR).

[0117] The first organic material is preferably a polyol having multiple hydroxyl groups in the molecule. Examples of polyols include polyether polyol, polyester polyol, and polyvinyl acetal. Two or more organic materials may be used in combination as the first organic material.

[0118] The second organic material is preferably an isocyanate compound, an epoxy resin, or a melamine resin having multiple functional groups in the molecule. Two or more organic materials may be used in combination as the second organic material. Among the second organic materials, an isocyanate compound is preferred.

[0119] Examples of the isocyanate compound include aromatic polyisocyanates such as diphenylmethane diisocyanate (MDI) and tolylene diisocyanate (TDI), and aliphatic polyisocyanates such as hexamethylene diisocyanate (HDI). Modified products of these polyisocyanates, such as modified products having carbodiimide or urethane, may also be used.

[0120] The epoxy resin is not particularly limited as long as it is a resin having an epoxy ring, and examples thereof include bisphenol A type epoxy resin, biphenyl skeleton epoxy resin, cyclopentadiene skeleton epoxy resin, and naphthalene skeleton epoxy resin.

[0121] The melamine resin is not particularly limited as long as it is an organic nitrogen compound having a triazine ring at the center of its structure and three amino groups on the periphery thereof, and examples thereof include alkylated melamine resins, etc. Modified melamine resins may also be used.

[0122] When the capacitor of the present invention is a film capacitor, the dielectric film constituting the element body of the capacitor element is preferably obtained by forming a resin solution containing the first organic material and the second organic material into a film, and then heat-treating it to harden it.

[0123] When the capacitor of the present invention is a film capacitor, the dielectric film constituting the element body of the capacitor element may contain a vapor-deposited polymer film as a main component. The vapor-deposited polymer film may or may not have at least one of a urethane bond and a urea bond.

[0124] The vapor deposition polymerized film refers to a film formed by vapor deposition polymerization, and is basically included in the category of curable resins.

[0125] When the capacitor of the present invention is a film capacitor, the dielectric film constituting the element body of the capacitor element may contain a thermoplastic resin as a main component, such as polypropylene, polyethersulfone, polyetherimide, or polyarylate.

[0126] When the capacitor of the present invention is a film capacitor, the dielectric film constituting the element body of the capacitor element may contain additives for imparting other functions. For example, adding a leveling agent can impart smoothness. The additive is preferably a material having a functional group reactive with a hydroxyl group and / or an isocyanate group and forming part of the crosslinked structure of the cured product. Examples of such materials include resins having at least one functional group selected from the group consisting of epoxy groups, silanol groups, and carboxyl groups.

[0127] When the capacitor of the present invention is a film capacitor, the thickness of the dielectric film constituting the element body of the capacitor element is not particularly limited, but may be set appropriately according to the required capacitance and required element volume of the capacitor to be produced.

[0128] The thickness of the dielectric film can be measured using an optical film thickness meter.

[0129] When the capacitor of the present invention is a film capacitor, the type of metal contained in the metal layer constituting the element body of the capacitor element is not particularly limited, but it is preferable that the metal layer contains any one selected from the group consisting of aluminum (Al), titanium (Ti), zinc (Zn), magnesium (Mg), tin (Sn), and nickel (Ni).

[0130] When the capacitor of the present invention is a film capacitor, the thickness of the metal layer constituting the element body of the capacitor element is not particularly limited, but from the viewpoint of suppressing damage to the metal layer, the thickness of the metal layer is preferably 5 nm or more and 40 nm or less.

[0131] The thickness of the metal layer can be determined by observing a cross section of the metallized film cut in the thickness direction using an electron microscope such as a field emission scanning electron microscope (FE-SEM).

[0132] The capacitor of the present invention is not limited to the above-described embodiment, as long as the height of the guide groove located on the opening side of the outer case is lower than the height of the side wall located on the opening side of the outer case, or the corners of the sides of the guide groove located on the opening side of the outer case are chamfered. Therefore, various applications and modifications can be made within the scope of the present invention regarding the configuration and manufacturing conditions of the capacitor.

[0133] In the film capacitor of the present invention, when a pair of external electrodes are provided on both end surfaces of the element body and a pair of lead-out terminals are electrically connected to each of the pair of external electrodes, it is sufficient that at least one lead-out terminal and the guide groove for regulating the position of that lead-out terminal satisfy the relationship described in the above embodiment.

[0134] Although FIG. 1 shows an example in which a single capacitor element is housed inside a single exterior case, multiple capacitor elements may be housed inside a single exterior case, as described in, for example, JP 2012-69840 A.

[0135] In the capacitor of the present invention, the portion where the lead terminal, such as a lead wire, is electrically connected to the external electrode of the capacitor element is located in a small area of ​​the external electrode, so that if a load is applied to the lead terminal, the lead terminal may separate from the external electrode. Therefore, it is preferable that a filling resin is positioned inside the outer case on the outside of the external electrode of the capacitor element and the lead terminal, and tightly fixes them together. In this way, even if a load is applied to the protruding portion of the lead terminal, the filling resin reinforces the connection between the lead terminal and the external electrode, preventing them from separating.

[0136] The connection position between the external electrode and the lead-out terminal is not particularly limited, and may be, for example, on the bottom side of the case as shown in FIG. 2 or FIG. 3, or on the opening side of the case as shown in FIG. 1 of Japanese Patent No. 4733566, or may be in the center of the external electrode.

[0137] The present specification discloses the following:

[0138] <1> A capacitor comprising: a capacitor element including an element body and an external electrode provided on an end surface of the element body; a lead terminal electrically connected to the external electrode; an outer case in which the capacitor element is housed so that the lead terminal protrudes outward; and a filling resin filled between the capacitor element and the outer case, wherein the outer case is a bottomed cylindrical shape having an opening at one end, and includes a bottom wall facing the opening and sealing the other end, and a side wall protruding from the bottom wall toward the opening, a guide groove for regulating the position of the lead terminal is provided on an inner surface of the outer case, the guide groove protruding from the side wall and extending from the opening side to the bottom wall side, and a height of the guide groove located on the opening side of the outer case is lower than a height of the side wall located on the opening side of the outer case.

[0139] <2> The capacitor according to <1>, wherein a corner of the side of the guide groove located on the opening side of the exterior case is chamfered.

[0140] <3> A capacitor comprising: a capacitor element including an element body and an external electrode provided on an end surface of the element body; a lead terminal electrically connected to the external electrode; an outer case in which the capacitor element is housed so that the lead terminal protrudes outward; and a filling resin filled between the capacitor element and the outer case, wherein the outer case is a bottomed cylindrical shape having an opening at one end, and includes a bottom wall facing the opening and sealing the other end, and a side wall protruding from the bottom wall toward the opening, a guide groove for regulating the position of the lead terminal is provided on an inner surface of the outer case, the guide groove protruding from the side wall and extending from the opening side to the bottom wall side, and a corner of the guide groove located on the opening side of the outer case is chamfered.

[0141] <4> The capacitor according to <1> or <2>, wherein a stepped surface is provided between the side wall located on the opening side of the exterior case and the guide groove.

[0142] <5> The capacitor according to <1> or <2>, wherein a flat inclined surface is provided between the side wall located on the opening side of the exterior case and the guide groove.

[0143] <6> The capacitor according to <1> or <2>, wherein a curved inclined surface is provided between the side wall located on the opening side of the exterior case and the guide groove.

[0144] <7> The capacitor according to any one of <1> to <6>, wherein, when the guide groove is viewed from the opening side of the outer case, a planar shape of the side of the guide groove located on the opening side of the outer case is V-shaped.

[0145] <8> The capacitor according to any one of claims <1> to <6>, wherein, when the guide groove is viewed from the opening side of the outer case, a planar shape of the side of the guide groove located on the opening side of the outer case is a semicircular arc shape or a semi-elliptical arc shape.

[0146] <9> The capacitor according to any one of <1> to <6>, wherein, when the guide groove is viewed from the opening side of the outer case, a planar shape of a side of the guide groove located on the opening side of the outer case is an angular U-shape.

[0147] <10> The capacitor according to any one of <1> to <9>, wherein the extraction terminal is a lead wire having a plating layer on the surface thereof.

[0148] <11> The capacitor according to any one of <1> to <10>, wherein the lead wire has an outer diameter of 1 mm or more.

[0149] <12> The capacitor according to any one of <1> to <11>, wherein the outer case is a resin case.

[0150] <13> The capacitor according to <12>, wherein the resin case contains a liquid crystal polymer.

[0151] <14> The capacitor according to any one of <1> to <13>, wherein the element body is a laminate including a metallized film in which a metal layer is provided on at least one main surface of a dielectric film, and the external electrodes are connected to the metal layer.

[0152] <15> The capacitor according to <14>, wherein the laminate is a wound body in which the metallized film is wound in a laminated state.

[0153] REFERENCE SIGNS LIST 1 Capacitor 10 Capacitor element 11 Element body 12 External electrode 20 Lead-out terminal 30 Outer case 31 Opening 32 Bottom wall 33 Side wall 33a Recess 34 Guide groove 40 Filled resin 51 First metallized film 52 Second metallized film 53 First dielectric film 54 Second dielectric film 55 First metal layer 56 Second metal layer H Height difference between the side wall located on the opening side of the outer case and the guide groove W Width of the guide groove protruding from the side wall X Side of the guide groove located on the opening side of the outer case

Claims

1. A capacitor element including an element body and an external electrode provided on an end surface of the element body; A lead terminal electrically connected to the external electrode; an exterior case in which the capacitor element is housed so that the lead-out terminal protrudes outward; a filling resin filled between the capacitor element and the exterior case, the exterior case is a cylindrical case having an opening at one end and a bottom, the case including a bottom wall facing the opening and sealing the other end, and a side wall protruding from the bottom wall toward the opening, a guide groove for regulating the position of the lead-out terminal is provided on the inner surface of the outer case; the guide groove projects from the side wall and extends from the opening side to the bottom wall side, the lead-out terminal is linear, and the lead-out terminal and the guide groove are in line contact over the entire length of the guide groove; A capacitor, wherein a height of the guide groove located on the opening side of the outer case is lower than a height of the side wall located on the opening side of the outer case.

2. The capacitor according to claim 1 , wherein a corner of a side of the guide groove located on the opening side of the exterior case is chamfered.

3. A capacitor element including an element body and an external electrode provided on an end surface of the element body; A lead terminal electrically connected to the external electrode; an exterior case in which the capacitor element is housed so that the lead-out terminal protrudes outward; a filling resin filled between the capacitor element and the exterior case, the exterior case is a cylindrical case having an opening at one end and a bottom, the case including a bottom wall facing the opening and sealing the other end, and a side wall protruding from the bottom wall toward the opening, a guide groove for regulating the position of the lead-out terminal is provided on the inner surface of the outer case; the guide groove projects from the side wall and extends from the opening side to the bottom wall side, the lead-out terminal is linear, and the lead-out terminal and the guide groove are in line contact over the entire length of the guide groove; a corner of a side of the guide groove located on the opening side of the exterior case is chamfered.

4. The capacitor according to claim 1 , wherein a step surface is provided between the side wall located on the opening side of the exterior case and the guide groove.

5. The capacitor according to claim 1 , wherein a flat inclined surface is provided between the side wall located on the opening side of the exterior case and the guide groove.

6. The capacitor according to claim 1 , wherein a curved inclined surface is provided between the side wall located on the opening side of the exterior case and the guide groove.

7. The capacitor according to any one of claims 1 to 3, wherein when the guide groove is viewed from the opening side of the outer case, a planar shape of the side of the guide groove located on the opening side of the outer case is V-shaped.

8. The capacitor according to any one of claims 1 to 3, wherein when the guide groove is viewed from the opening side of the outer case, a planar shape of the side of the guide groove located on the opening side of the outer case is a semicircular arc shape or a semi-elliptical arc shape.

9. The capacitor according to any one of claims 1 to 3, wherein when the guide groove is viewed from the opening side of the outer case, a planar shape of the side of the guide groove located on the opening side of the outer case is an angular U-shape.

10. 4. The capacitor according to claim 1, wherein the extraction terminal is a lead wire having a plating layer on a surface thereof.

11. The capacitor according to claim 10, wherein the lead wire has an outer diameter of 1 mm or more.

12. The capacitor according to any one of claims 1 to 3, wherein the exterior case is a resin case.

13. The capacitor of claim 12 , wherein the resin case comprises a liquid crystal polymer.

14. the element body is a laminate including a metallized film having a metal layer provided on at least one main surface of a dielectric film, The capacitor according to claim 1, wherein the external electrodes are connected to the metal layers.

15. The capacitor according to claim 14 , wherein the laminate is a wound body in which the metallized films are wound in a stacked state.