Capacitor and method for manufacturing a capacitor

Abstract

Provided is a capacitor with which it is possible to suppress variation of the resin amount of an encapsulating resin and improve the dimensional accuracy of the height of the upper surface of the capacitor. The capacitor (1) comprises: a capacitor element (10); a case (50) that has an opening (51f) and accommodates the capacitor element (10); a lid (60) that has through-holes (61aa–61af) and is disposed in the opening (51f) in a state in which the capacitor element (10) is accommodated in the case (50); and an encapsulating resin (70) that is injected into the case (50) and encapsulates the capacitor element (10).

Description

[Technical Field]

[0001] The present invention relates to a capacitor in which a capacitor element housed in a case is sealed with a sealing resin, and a method for manufacturing the same. [Background Art]

[0002] For example, a conventional capacitor disclosed in Japanese Patent Application Laid-Open No.2022-100801 (hereinafter referred to as "Patent Document 1") includes a capacitor element having a first end face electrode and a second end face electrode. With a first bus bar connected to the first end face electrode and a second bus bar connected to the second end face electrode, the capacitor element is housed in a box-shaped case having an opening on one face. Thereafter, the capacitor element is sealed with the sealing resin by injecting the sealing resin into an empty space of the case.

[0003] The case of the capacitor described in Patent Document 1 has a bottom portion, a peripheral wall portion, and an indicator portion. The bottom portion is provided below a housing space that houses the capacitor element. The peripheral wall portion surrounds four sides of the housing space. The indicator portion serves as an indicator for a resin surface of the sealing resin. The indicator portion includes an upper-limit indicator portion and a lower-limit indicator portion. The upper-limit indicator portion extends upward from the bottom portion and is formed at a position lower than the upper end of the peripheral wall portion. The lower-limit indicator portion is formed at a position lower than the upper end of the upper-limit indicator portion. The upper-limit indicator portion and the lower-limit indicator portion are integrally formed. [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] Due to size constraints of capacitors, it can sometimes be difficult to incorporate an indicator into the case. Even when it is possible to incorporate an indicator into the case, the following challenges exist. Specifically, in automotive capacitors, the required current is large, necessitating cooling. Heat dissipation components are sometimes placed on the top surface (the resin surface of the sealing resin) of the capacitor with a case opening. In this case, high precision is required for the height of the resin surface. Therefore, even if an indicator is incorporated into the case, variations in the amount of sealing resin injected may result in the dimensional accuracy of the resin surface height not meeting the requirements. To suppress variations in the amount of resin, it is conceivable to inject the sealing resin in multiple stages while varying the amount of resin injected per unit time. However, this increases the process time. Additionally, air bubbles that form between the injection of the sealing resin and its hardening can accumulate at the top of the case. In this case, the accumulated air bubbles at the top of the case can lower the top surface of the sealing resin, resulting in a thinner layer of sealing resin than intended.

[0005] The present invention aims to provide a capacitor that can suppress variations in the amount of resin in the sealing resin and improve the dimensional accuracy of the height of the top surface of the capacitor. [Means for solving the problem]

[0006] The first aspect of the present invention is, Capacitor element and A case having an opening and housing the capacitor element, A lid having a through portion and positioned over the opening with the capacitor element housed in the case, A sealing resin injected into the case to seal the capacitor element, It is a capacitor having [a certain characteristic].

[0007] A second aspect of the present invention is, A lid with a through-hole is placed over the opening of the case housing the capacitor element. With the lid positioned in the opening, sealing resin is injected into the case through the through-hole to seal the capacitor element. This is a method for manufacturing capacitors.

[0008] A third aspect of the present invention is, The capacitor element is sealed by injecting a sealing resin into the case containing the capacitor element. A lid having a through-hole is placed at the opening of the case containing the capacitor element sealed with the aforementioned sealing resin. This is a method for manufacturing capacitors. [Effects of the Invention]

[0009] According to the present invention, variations in the amount of resin in the sealing resin can be suppressed, and the dimensional accuracy of the height of the top surface of the capacitor can be improved. [Brief explanation of the drawing]

[0010] [Figure 1] Perspective view of the capacitor according to the first embodiment [Figure 2] Exploded perspective view of the capacitor of the first embodiment, excluding the sealing resin. [Figure 3] Perspective view of the capacitor element of the first embodiment [Figure 4] Perspective view of the first busbar of the first embodiment [Figure 5] Perspective view of the second busbar of the first embodiment [Figure 6] Perspective view of the insulating member of the first embodiment [Figure 7] (a) is a perspective view of the case of the first embodiment from an oblique upward direction, and (b) is a perspective view of the case of the first embodiment from a different oblique upward direction than (a). [Figure 8] (a) is a perspective view of the lid of the first embodiment viewed from an oblique upward direction, and (b) is a perspective view of the lid of the first embodiment viewed from an oblique downward direction. [Figure 9] Diagram illustrating the manufacturing process of the capacitor according to the first embodiment. [Figure 10] Figure 9 is a diagram illustrating the capacitor manufacturing process. [Figure 11] Explanatory view of the capacitor manufacturing process following FIG. 10 [Figure 12] Explanatory view of the capacitor manufacturing process following FIG. 11 [Figure 13] Perspective view of the capacitor according to the second embodiment [Figure 14] (a) is a perspective view of the lid of the second embodiment as viewed from diagonally above, and (b) is a perspective view of the lid of the second embodiment as viewed from diagonally below [Figure 15] (a) is a perspective view of the lid of the capacitor of the third embodiment as viewed from diagonally above, and (b) is a perspective view of the lid of the third embodiment as viewed from diagonally below [Figure 16] (a) is a schematic view illustrating one modified example of a case and a lid, (b) is a schematic view illustrating another modified example of the case and the lid, and (c) is a schematic view illustrating yet another modified example of the case and the lid [Figure 17] (a) is a schematic view illustrating one modified example of a top plate portion of a lid, and (b) is a schematic view illustrating another modified example of the top plate portion of the lid MODES FOR CARRYING OUT THE INVENTION

[0011] <<First Embodiment>> Hereinafter, the capacitor 1 according to the first embodiment will be described in detail with reference to the accompanying drawings.

[0012] The structure of the capacitor 1 according to the first embodiment will be described with reference to FIGS. 1 to 8. Note that the x-axis, y-axis, and z-axis in each of FIGS. 1 to 8 and each of FIGS. 9 to 12 are in the same direction relative to one another. The opening surface of the case 50 in the completed state of the capacitor 1 is an xy plane. The short side surface of the case 50 is a yz plane. The long side surface of the case 50 is a zx plane. The capacitor 1 and each constituent element (capacitor element 10, first bus bar 20, second bus bar 30, insulating member 40, case 50, lid 60, sealing resin 70) are illustrated in this manner. The same applies to the x-axis, y-axis, and z-axis in FIG. 13 and FIG. 14 referred to in the second embodiment and in FIG. 15 referred to in the third embodiment.

[0013] As shown in Figures 1 and 2, the capacitor 1 includes a metallized film capacitor element (capacitor element), a first busbar 20, a second busbar 30, insulating paper, an insulating member 40 such as an insulating board, a case 50, a lid 60, and a sealing resin 70.

[0014] As shown in Figure 3, the capacitor element 10 has an element body 11, a first end face electrode 12, and a second end face electrode 13. The first end face electrode 12 is formed on the first end face of the element body 11 by spraying a metal such as zinc. The second end face electrode 13 is formed on the second end face of the element body 11 by spraying a metal such as zinc.

[0015] The element body portion 11 is formed by stacking two metallized films, each having aluminum deposited on a dielectric film, winding or laminating the stacked metallized films, and pressing them into a flattened shape. The element body 11 of this embodiment is not limited to this, and may be formed from a metallized film on which other metals such as zinc and magnesium have been deposited, or from a metallized film on which multiple of these metals have been deposited, or from a metallized film on which alloys of these metals have been deposited.

[0016] The first end electrode 12 and the first busbar 20 are electrically connected by soldering them together so that the first busbar 20 is in contact with the first end electrode 12. The second end electrode 13 and the second busbar 30 are electrically connected by soldering them together so that the second busbar 30 is in contact with the second end electrode 13. The first busbar 20 and the second busbar 30 are each made of a conductive material such as copper. In this embodiment, the first end electrode 12 and the first busbar 20 are the P-pole side, and the second end electrode 13 and the second busbar 30 are the N-pole side. Alternatively, the first end electrode 12 and the first busbar 20 may be the N-pole side, and the second end electrode 13 and the second busbar 30 may be the P-pole side.

[0017] In this embodiment, the capacitor 1 has one capacitor element 10, but it is not limited to this, and may have two or more capacitor elements 10.

[0018] The first busbar 20 is formed from a conductive material such as copper and has the shape shown in Figure 4. The first busbar 20 has a flat end electrode contact portion 21. The end electrode contact portion 21 contacts the first end electrode 12 when the capacitor 1 is assembled. The end electrode contact portion 21 has a substantially rectangular shape in an xy-plane view. The end electrode contact portion 21 has two through portions 21a. Each through portion 21a is rectangular in an xy-plane view. Each through portion 21a has a projection 21b that is used when soldering to the first end electrode 12.

[0019] The first busbar 20 has a flat, plate-shaped first lead-out portion 22. The first lead-out portion 22 extends from one side of the end face electrode contact portion 21 (the side on the positive y-axis side of the end face electrode contact portion 21) in a direction perpendicular to the surface of the end face electrode contact portion 21 (positive z-axis direction). The first busbar 20 has two second lead-outs 23. Each second lead-out 23 extends in the positive z-axis direction from the end of the first lead-out 22 opposite to the end electrode contact portion 21.

[0020] The first busbar 20 has two external connection terminals 24. Each external connection terminal 24 extends from the end of the second lead-out 23 opposite to the first lead-out 22, parallel to the end face electrode contact 21 (in the negative y-axis direction) on the side facing the end face electrode contact 21. Each external connection terminal 24 has a through-hole 24a. The through-hole 24a is approximately circular in shape in an xy-plane view. The through-hole 24a fastens the first busbar 20 to the external wiring.

[0021] The first busbar 20 is manufactured by first creating a flat plate having portions corresponding to an end face electrode contact portion 21, a first lead portion 22, two second lead portions 23, and two external connection terminal portions 24 using a mold, and then bending it.

[0022] The second busbar 30 is formed from a conductive material such as copper and has the shape shown in Figure 5. The second busbar 30 has a flat end electrode contact portion 31. The end electrode contact portion 31 contacts the second end electrode 13 when the capacitor 1 is assembled. The end electrode contact portion 31 has a substantially rectangular shape in an xy-plane view. The end electrode contact portion 31 has through portions 31a. Each through portion 31a is rectangular in an xy-plane view. The through portions 31a have projections 31b that are used when soldering to the second end electrode 13.

[0023] The second busbar 30 has a flat first lead-out portion 32. The first lead-out portion 32 extends from one side of the end face electrode contact portion 31 (the side on the positive y-axis side of the end face electrode contact portion 31) in a direction perpendicular to the surface of the end face electrode contact portion 31 (positive z-axis direction).

[0024] In the assembled state of capacitor 1, the first lead portion 22 of the first busbar 20 and the first lead portion 32 of the second busbar 30 partially overlap in a view from the zx plane. The first lead portion 22 is located closer to the capacitor element 10 than the first lead portion 32. An insulating member 40 is placed between the first lead portion 22 and the first lead portion 32. This ensures insulation between the first busbar 20 and the second busbar 30. However, if insulation between the first busbar 20 and the second busbar 30 can be ensured, it is not necessary to place the insulating member 40 between the first lead portion 22 and the first lead portion 32.

[0025] The second busbar 30 has two second lead-outs 33. Each second lead-out 33 extends in the positive z-axis direction from the end of the first lead-out 32 opposite to the end face electrode contact portion 31.

[0026] The second busbar 30 has two external connection terminals 34. Each external connection terminal 34 extends from the end of the second lead-out 33 opposite to the first lead-out 32, parallel to the end-face electrode contact 31 (in the negative y-axis direction) on the side facing the end-face electrode contact 31. Each external connection terminal 34 has a through-hole 34a. The through-hole 34a is substantially circular in xy-plane view. The through-hole 34a fastens the second busbar 30 to the external wiring.

[0027] The second busbar 30 is manufactured by first creating a flat plate having portions corresponding to an end face electrode contact portion 31, a first lead portion 32, two second lead portions 33, and two external connection terminal portions 34 using a mold, and then bending it.

[0028] The insulating member 40 is formed of an insulating material. As shown in Figure 6, the insulating member 40 has a substantially rectangular outer shape in a plan view along the zx axis. The insulating member 40 is positioned between the first lead portion 22 of the first busbar 20 and the first lead portion 32 of the second busbar 30, thereby insulating the first busbar 20 and the second busbar 30.

[0029] Case 50 is formed from various materials, such as organic materials like resins and plastics such as polyphenylene sulfide (PPS) and polybutylene terephthalate (PBT), and inorganic materials such as ceramics. Case 50 has the shape shown in Figures 7(a) and 7(b).

[0030] Case 50 has a flat bottom 51a. The bottom 51a has an outer diameter that is approximately rectangular in an xy plane view. Case 50 also has a first side 51b, a second side 51c, a third side 51d, and a fourth side 51e. The first to fourth side 51b to 51e are flat plates that extend from the four edges of the bottom 51a in a direction perpendicular to the inner surface (inner bottom surface) of the bottom 51a (positive z-axis direction). Case 50 is a rectangular box shape with an opening 51f on the surface opposite the inner bottom surface of the bottom 51a.

[0031] The case 50 has two first mounting portions 52a and two second mounting portions 52b. The two first mounting portions 52a are located on the outer surface of the second side portion 51c. The two second mounting portions 52b are located on the outer surface of the fourth side portion 51e. Each first mounting portion 52a and each second mounting portion 52b has a through portion. The capacitor 1 is attached to an external device by the first mounting portions 52a and the second mounting portions 52b.

[0032] The case 50 has two first fitting portions 53 on the inner surface of the second side portion 51c. Each first fitting portion 53 has a first lower fitting portion 53a and a first upper fitting portion 53b on the inner surface of the second side portion 51c. The first lower fitting portion 53a and the first upper fitting portion 53b are spaced apart. In a yz plan view, the upper and lower surfaces of the first lower fitting portion 53a are parallel to the inner bottom surface of the bottom portion 51a. The first fitting portion 62 of the lid 60 (see Figure 8) is fitted between the upper surface of the first lower fitting portion 53a and the lower surface of the first upper fitting portion 53b.

[0033] The case 50 has two second fitting portions 54 on the inner surface of the fourth side portion 51e. Each second fitting portion 54 has a second lower fitting portion 54a and a second upper fitting portion 54b on the inner surface of the fourth side portion 51e. The second lower fitting portion 54a and the second upper fitting portion 54b are spaced apart. In a yz plan view, the upper and lower surfaces of the second lower fitting portion 54a are parallel to the inner bottom surface of the bottom portion 51a. The second fitting portion 63 of the lid 60 (see Figure 8) is fitted between the upper surface of the second lower fitting portion 54a and the lower surface of the second upper fitting portion 54b.

[0034] When the inner bottom surface of the bottom portion 51a is used as the height reference plane, the height of the upper surfaces of the two first lower fitting portions 53a and the height of the upper surfaces of the two second lower fitting portions 54a are equal. Also, the height of the lower surfaces of the two first upper fitting portions 53b and the height of the lower surfaces of the two second upper fitting portions 54b are equal.

[0035] The case 50 is formed integrally with, for example, a bottom portion 51a, first to fourth side portions 51b to 51e, two first mounting portions 52a, two second mounting portions 52b, two first fitting portions 53, and two second fitting portions 54.

[0036] The lid 60 is made of various materials, such as organic materials like resins and plastics such as polyphenylene sulfide (PPS) and polybutylene terephthalate (PBT), inorganic materials like ceramics, and metals like aluminum. The lid 60 has the shape shown in Figures 8(a) and 8(b).

[0037] The lid 60 has a flat top plate portion 61a. The top plate portion 61a has a roughly rectangular shape in an xy-plane view. The lid 60 also has a first side portion 61b, a second side portion 61c divided into two, a third side portion 61d, and a fourth side portion 61e divided into two. The first to fourth side portions 61b to 61e are flat plates that extend from each of the four sides of the top plate portion 61a in a direction perpendicular to the inner surface (the negative z-axis side) of the top plate portion 61a (the negative z-axis side). The top surface of the top plate portion 61a (the outer surface of the lid) is a roughly flat surface.

[0038] The top plate portion 61a has two large-diameter through-holes 61aa and 61ab, four through-holes 61ac, 61ad, and 61ae, twelve small-diameter through-holes 61af, and a notch 61ag. Each of the large-diameter through-holes 61aa and 61ab is circular in xy-plane view. Each of the through-holes 61ac, 61ad, and 61ae is semicircular in xy-plane view. Each of the small-diameter through-holes 61af is circular in xy-plane view. The notch 61ag is rectangular in xy-plane view.

[0039] The through-holes 61aa to 61ae are mainly used for injecting the sealing resin 70. The through-hole 61af is mainly used for releasing air bubbles generated during the injection of the sealing resin 70 to the outside of the resin. The diameters of the through-holes 61aa, 61ab, and the through-holes 61ac to 61ae are larger than the diameter of the through-hole 61af. The notch 61ag allows the first lead-out portion 22 of the first busbar 20, the first lead-out portion 32 of the second busbar 30, and the insulating member 40 to be pulled out from inside the capacitor 1 to outside the capacitor 1 when the capacitor 1 is assembled (see Figure 1). The number of through-holes for injecting the sealing resin 70 may be other than 6. The number of through-holes for releasing air bubbles may be other than 12.

[0040] The lid 60 has two first fitting portions 62. Each first fitting portion 62 extends parallel to the top plate portion 61a (in the positive x-axis direction) from the end of the two divided second side portions 61c opposite to the top plate portion 61a. The thickness of the first fitting portion 62 (thickness in the z-axis direction) is approximately equal to the gap (distance in the z-axis direction) between the upper surface of the first lower fitting portion 53a and the lower surface of the first upper fitting portion 53b of the case 50. Each first fitting portion 62 is fitted between the upper surface of the first lower fitting portion 53a and the lower surface of the first upper fitting portion 53b.

[0041] The lid 60 has two second fitting portions 63. The second fitting portions 63 extend from the end of the divided fourth side portion 61e opposite to the top plate portion 61a, parallel to the top plate portion 61a (in the negative x-axis direction). The thickness of the second fitting portion 63 (thickness in the z-axis direction) is approximately equal to the gap (distance in the z-axis direction) between the upper surface of the second lower fitting portion 54a and the lower surface of the second upper fitting portion 54b of the case 50. Each second fitting portion 63 is fitted between the upper surface of the second lower fitting portion 54a and the lower surface of the second upper fitting portion 54b.

[0042] The lid 60 has three extensions 64. Each extension 64 extends downward (in the negative z-axis direction) from the lower surface of the top plate portion 61a. Each extension 64 has a similar shape. The first extension 64 (left side in Figure 8(b)) has a base 64a, a first lower limit indicator 64b, and a second lower limit indicator 64c. The base 64a extends from the lower surface of the top plate portion 61a between the through portions 61ac and 61aa in a direction perpendicular to the lower surface of the top plate portion 61a (negative z-axis direction). The first lower limit indicator 64b extends from the lower part of the side surface of the base 64a to a part of the through portion 61ac in an xy-plane view. The second lower limit indicator 64c extends from the lower part of the side surface of the base 64a to a part of the through portion 61aa in an xy-plane view.

[0043] The second extension 64 (center of Figure 8(b)) has a base 64a, a first lower limit indicator 64b, and a second lower limit indicator 64c. The base 64a extends from the lower surface of the top plate portion 61a between the through portions 61aa and 61ab in a direction perpendicular to the lower surface of the top plate portion 61a (negative z-axis direction). The first lower limit indicator 64b extends from the lower part of the side surface of the base 64a to a part of the through portion 61aa in an xy-plane view. The second lower limit indicator 64c extends from the lower part of the side surface of the base 64a to a part of the through portion 61ab in an xy-plane view.

[0044] The third extension 64 (right side in Figure 8(b)) has a base 64a, a first lower limit indicator 64b, and a second lower limit indicator 64c. The base 64a extends from the lower surface of the top plate portion 61a between the through portions 61ab and 61ad in a direction perpendicular to the lower surface of the top plate portion 61a (negative z-axis direction). The first lower limit indicator 64b extends from the lower part of the side surface of the base 64a to a part of the through portion 61ab in an xy-plane view. The second lower limit indicator 64c extends from the lower part of the side surface of the base 64a to a part of the through portion 61ad in an xy-plane view. The upper surface (positive z-axis side) of each first lower limit indicator portion 64b and the upper surface (positive z-axis side) of each second lower limit indicator portion 64c are located below (negative z-axis direction) the lower surface of the top plate portion 61a.

[0045] The upper surfaces of the first lower limit indicator portion 64b and the second lower limit indicator portion 64c of each extension portion 64 serve as indicators of the lower limit of the amount of sealing resin 70 injected. In the first extension portion 64, the first lower limit indicator portion 64b is visible from the through portion 61ac, and the second lower limit indicator portion 64c is visible from the through portion 61aa. In the second extension 64, the first lower limit indicator portion 64b is visible from the through portion 61aa. The second lower limit indicator portion 64c is visible from the through portion 61ab. In the third extension portion 64, the first lower limit indicator portion 64b is visible from the through portion 61ab. The second lower limit indicator portion 64c is visible from the through portion 61ad.

[0046] Since the upper surfaces of the first lower limit indicator portion 64b and the second lower limit indicator portion 64c of each extension portion 64 serve as indicators of the lower limit of the amount of sealing resin 70 to be injected, the extension portion 64 becomes embedded in the sealing resin after the sealing resin 70 is injected and hardened. For this reason, even if the lid 60 (the lower surface of the top plate portion 61a) and the resin surface of the sealing resin 70 are separated, at least the tip of the extension portion 64 is embedded in the sealing resin 70, so heat can be dissipated from the sealing resin 70 via the extension portion 64.

[0047] In this embodiment, the first to fourth side portions 61b to 61e, as well as the first fitting portion 62 and the second fitting portion 63, also come into contact with the sealing resin 70. This allows heat to be dissipated from the sealing resin 70.

[0048] In this embodiment, the top surface of the top plate portion 61a is used as an indicator of the upper limit of the amount of sealing resin 70 injected. Furthermore, the lid 60 has a shape and dimensions that cover substantially the entire opening 51f of the case 50.

[0049] The lid 60 is formed by integrally integrating, for example, a top plate portion 61a, first to fourth side portions 61b to 61e, two first fitting portions 62, two second fitting portions 63, and three extension portions 64.

[0050] The sealing resin 70 seals the capacitor element 10, a portion of the first busbar 20, a portion of the second busbar 30, and a portion of the insulating member 40. The sealing resin 70 is, for example, epoxy resin. However, the sealing resin 70 is not limited to epoxy resin; various insulating materials used as sealing resins for electronic components can be used. The sealing resin 70 is formed by being injected into the case 50 in a liquid state and then curing.

[0051] The manufacturing process for capacitor 1 will be described below with reference to Figures 9 to 12. Note that the manufacturing process for capacitor 1 described below is just one example; any assembly sequence that allows capacitor 1 to be assembled to the state shown in Figure 1 is acceptable.

[0052] As shown in Figure 9(a), the insulating member 40 is attached to the y-axis negative side surface of the first lead-out portion 32 of the second busbar 30. This results in the state shown in Figure 9(b).

[0053] As shown in Figure 10(a), the second busbar 30, with the insulating member 40 attached, is positioned so that the upper surface (positive z-axis side) of the end face electrode contact portion 31 contacts the second end face electrode 13 of the capacitor element 10. The first busbar 20 is positioned so that the lower surface (negative z-axis side) of the end face electrode contact portion 21 contacts the first end face electrode 12 of the capacitor element 10. In this state, the second busbar 30 is soldered to the second end face electrode 13 using the projection 31b of the second busbar 30. This electrically connects the second busbar 30 and the second end face electrode 13. The first busbar 20 is also soldered to the first end face electrode 12 using the projection 21b of the first busbar 20. This electrically connects the first busbar 20 and the first end face electrode 12. This results in the state shown in Figure 10(b). In the following, the unit assembled with the capacitor element 10, the first busbar 20, the second busbar 30, and the insulating member 40 in the state shown in Figure 10(b) will be referred to as the wiring unit 5 as appropriate.

[0054] As shown in Figure 11(a), the wiring unit 5 is placed into the case 50 through the opening 51f of the case 50. Then, the lid 60 is attached to the case 50. This results in the state shown in Figure 11(b).

[0055] To attach the lid 60 to the case 50, for example, first, the lid 60 is tilted so that the fourth side portion 61e is closer to the case 50 than the second side portion 61c, and the second fitting portion 63 of the lid 60 (see Figure 8) is fitted between the upper surface of the second lower fitting portion 54a and the lower surface of the second upper fitting portion 54b of the case 50. Next, the area near the second side portion 61c of the top plate portion 61a of the lid 60 is pushed toward the bottom portion 51a of the case 50, and the first fitting portion 62 of the lid 60 is fitted between the upper surface of the first lower fitting portion 53a and the lower surface of the first upper fitting portion 53b of the case 50.

[0056] With the lid 60 attached to the case 50 housing the wiring unit 5, as shown in Figure 12(a), a sealing resin 70 such as liquid epoxy resin is injected through the through-holes 61aa to 61ae formed in the lid 60. Then, by curing it at a predetermined curing temperature, the capacitor 1 shown in Figure 12(b) is completed. In this embodiment, the top surface of the top plate portion 61a of the lid 60 is used as an indicator of the upper limit of the amount of sealing resin 70 to be injected, and the upper surfaces of the first and second lower limit indicator portions 64b and 64c (see Figure 8) are used as indicators of the lower limit of the amount of sealing resin 70 to be injected.

[0057] According to the first embodiment, the amount of sealing resin 70 injected is adjusted by using the top surface of the top plate portion 61a of the lid 60 as an indicator of the upper limit of the amount of sealing resin 70 injected, and the upper surfaces of the first and second lower limit indicator portions 64b and 64c of the lid 60 as indicators of the lower limit of the amount of sealing resin 70 injected. This allows the thickness of the sealing resin 70 covering the top of the capacitor element 10 to be adjusted, and variations in the amount of resin can be suppressed. In addition, the top surface of the top plate portion 61a of the lid 60 becomes the top surface of the capacitor 1. Since the dimensional accuracy of the height of the top surface of the top plate portion 61a is higher than that of the resin surface of the sealing resin 70, the dimensional accuracy of the height of the top surface of the capacitor 1 is improved. As a result, even when heat dissipation components are placed on the top surface of the capacitor 1, for example, the required dimensional accuracy can be met. Furthermore, according to this embodiment, air bubbles generated between the injection of the sealing resin 70 and the hardening of the sealing resin 70 are discharged from the through-holes 61aa to 61ae. As a result, the accumulation of air bubbles between the resin surface of the sealing resin 70 and the lid 60 is suppressed. This prevents the sealing resin 70 from becoming thinner than intended.

[0058] Furthermore, since the extension portion 64 has indicator portions (a first lower limit indicator portion 64b and a second lower limit indicator portion 64c), the indicators (upper and / or lower limits) of the resin surface height can be arbitrarily set. In this embodiment, the lower limit of the resin surface height is set. Moreover, by providing the indicator portions on the extension portion 64, the indicator portions can be installed relatively easily, even when there are constraints on the size of the capacitor, compared to when the indicator portions are provided on the case.

[0059] Furthermore, by making the top surface of the top plate portion 61a of the lid 60 substantially flat, the top plate portion 61a of the heat dissipation components can be easily and accurately positioned on the top surface.

[0060] Furthermore, the lid 60 is sized to cover almost the entire opening 51f of the case 50. Therefore, the contact area between the top plate portion 61a of the lid 60 and the heat dissipation components placed on the top surface of the top plate portion 61a can be increased, thereby improving the heat dissipation performance of the capacitor 1.

[0061] Furthermore, by increasing the diameter of the through-holes 61aa to 61ae for injecting the sealing resin 70, the sealing resin 70 can be easily injected. Also, by decreasing the diameter of the through-hole 61af for releasing air bubbles generated during the injection of the sealing resin 70 to the outside of the resin, the contact area between the top plate portion 61a and the heat dissipation component can be increased. This improves the heat dissipation performance of the capacitor 1.

[0062] In this embodiment, the manufacturing process of the capacitor 1 was described in which the lid 60 is attached to the case 50 and then the sealing resin 70 is injected into the case 50. However, the lid 60 may be attached to the case 50 after the sealing resin 70 has been injected into the case 50. In this case, for example, the case 50 has an indicator portion on its side. Even when the lid 60 is attached to the case 50 after the sealing resin 70 has been injected into the case 50, any air bubbles that have formed between the injection of the sealing resin 70 and the hardening of the sealing resin 70 are discharged from the through-holes 61aa to 61ae. Therefore, the accumulation of air bubbles between the resin surface of the sealing resin 70 and the lid 60 is suppressed. This prevents the sealing resin 70 from becoming thinner than expected. Here, after injecting the sealing resin 70 into the case 50, the lid 60 may be attached to the case 50 before the sealing resin 70 has completely hardened. In this case as well, it is possible to prevent the sealing resin 70 from becoming thinner than intended.

[0063] ≪Second Embodiment≫ The capacitor 1A of the second embodiment will be described in detail below with reference to Figures 13 and 14. The capacitor 1A differs from the capacitor 1 of the first embodiment in that it has a different cover 60A. In the second embodiment, the cover 60A will be described mainly. Other components (first busbar 20, second busbar 30, insulating member 40, case 50) have the same structure in capacitor 1A and capacitor 1, and in the second embodiment, the same reference numerals are used and their description is omitted.

[0064] The lid 60A has a top plate portion 61aA, first to fourth side portions 61b to 61e, two first fitting portions 62, two second fitting portions 63, and three extension portions 64. The top surface of the top plate portion 61aA is substantially flat. In an xy-plane view, the top plate portion 61aA has two circular through portions 61aa, 61ab, four semicircular through portions 61ac to 61ae, and nine circular through portions 61af. The through-holes 61aa to 61ae are mainly used for injecting the sealing resin 70. The through-hole 61af is mainly used for releasing air bubbles generated during the injection of the sealing resin 70 to the outside of the resin. The diameters of the through-holes 61aa and 61ab, and the diameters of the through-holes 61ac to 61ae are larger than the diameter of the through-hole 61af. The top plate portion 61a of the first embodiment has 12 through-holes 61af, whereas the top plate portion 61aA of this embodiment has 9 through-holes 61af. Also, the top plate portion 61a of the first embodiment has a notch 61ag, whereas the top plate portion 61aA of this embodiment does not have a notch. The number of through-holes for injecting the sealing resin 70 may be a number other than 6. The number of through-holes for releasing air bubbles may be a number other than 9.

[0065] The lid 60 of the first embodiment has a shape and dimensions that cover substantially the entire opening 51f of the case 50. In contrast, the lid 60A of this embodiment has a shape and dimensions that cover only a portion of the opening 51f of the case 50, rather than substantially the entire opening. Specifically, the portion of the opening 51f indicated by the dotted arrow 80 is not covered by the lid 60A.

[0066] The second embodiment provides the same effects as the first embodiment. Furthermore, the second embodiment allows for greater flexibility in configuring the extensions of the first busbar 20 and the second busbar 30, while suppressing variations in the amount of sealing resin by the lid 60A, by using the portion not covered by the lid 60A.

[0067] ≪Third Embodiment≫ The capacitor of the third embodiment will now be described in detail with reference to Figure 15. The capacitor of the third embodiment differs from the capacitor 1 of the first embodiment in that it has a different cover 60B than the cover 60. In the third embodiment, the cover 60B will be described in detail. The other components (first busbar 20, second busbar 30, insulating member 40, case 50) have the same structure in the capacitor of the third embodiment and the capacitor 1 of the first embodiment, and therefore, in the third embodiment, the description and illustration of the other components will be omitted.

[0068] The lid 60B of this embodiment has a structure obtained by removing the extension portion 64 from the lid 60 of the first embodiment. The lid 60B has a top plate portion 61a, first to fourth side portions 61b to 61e, two first fitting portions 62, and two second fitting portions 63. In an xy-plane view, the top plate portion 61a has two circular through portions 61aa, 61ab, four semicircular through portions 61ac to 61ae, twelve circular through portions 61af, and a rectangular notch portion 61ag. The through-holes 61aa to 61ae are mainly used for injecting the sealing resin 70. The through-hole 61af is mainly used for releasing air bubbles generated during the injection of the sealing resin 70 to the outside of the resin. The diameters of the through-holes 61aa, 61ab, and the through-holes 61ac to 61ae are larger than the diameter of the through-hole 61af. The notch 61ag allows the first lead-out portion 22 of the first busbar 20, the first lead-out portion 32 of the second busbar 30, and the insulating member 40 to be pulled out from inside the capacitor to outside the capacitor when the capacitor 1 is assembled. The number of through-holes for injecting the sealing resin 70 may be other than 6. The number of through-holes for releasing air bubbles may be other than 12.

[0069] In this embodiment, the top surface of the lid 60B is used as an indicator of the upper limit of the amount of sealing resin 70 injected, and the bottom surface of the lid 61a is used as an indicator of the lower limit of the amount of sealing resin 70 injected. In order to use the lid 60B as an indicator of the upper and lower limits of the amount of sealing resin 70 injected, for example, the thickness of the lid 60B is adjusted.

[0070] In the third embodiment, the lid 60B uses the top surface of the top plate portion 61a as an indicator of the upper limit of the amount of sealing resin 70 injected, and the bottom surface of the top plate portion 61a as an indicator of the lower limit of the amount of sealing resin 70 injected, thereby adjusting the amount of sealing resin 70 injected. This allows the thickness of the sealing resin 70 covering the top of the capacitor element 10 to be adjusted, and variations in the amount of resin can be suppressed. Furthermore, the same effects as in the first embodiment can be achieved.

[0071] Furthermore, when the lower surface of the top plate portion 61a is used as an indicator of the lower limit of the amount of sealing resin 70 injected, it is preferable from the viewpoint of heat dissipation that the resin surface of the sealing resin 70 is in contact with the lower surface of the top plate portion 61a. However, contact between the lower surface of the top plate portion 61a and the sealing resin 70 is not essential. For example, the fact that the resin surface of the sealing resin 70 visible from the through-hole of the lid 60B reaches close to the lower surface of the top plate portion 61a is also included in the function of the lid 60B (through-hole) as an indicator.

[0072] Furthermore, various design modifications can be made to the aforementioned configuration. In the first to third embodiments, the lids 60, 60A, and 60B fit inside the first to fourth sides 51b to 51e of the case 50, but are not limited to this. For example, the case may fit inside the first to fourth sides of the lid. In this case, for example, the outer surface of the second side of the case has a first fitting portion, and the outer surface of the fourth side of the case has a second fitting portion. The lid has a first fitting portion extending parallel to the top plate from the lower end of the second side, and a second fitting portion extending parallel to the top plate from the lower end of the fourth side.

[0073] In the first to third embodiments, the covers 60, 60A, and 60B are fitted inside the first to fourth sides 51b to 51e of the case 50, but are not limited to this. For example, they may be as shown in Figures 16(a) to (c). Figures 16(a) to (c) are schematic top views of the capacitor, and for the sake of simplicity in illustration, the first busbar 20, the second busbar 30, and the insulating member 40 are omitted from the illustration.

[0074] The top plate portion 61aC of the modified lid 60C shown in Figure 16(a) has through-holes 61aaC to 61aeC for resin injection, through-holes 61afC for releasing air bubbles, and a notch 61agC for drawing out the first busbar 20, the second busbar 30, and the insulating member 40 to the outside of the capacitor 1. The lid 60C also has an outer shape that covers substantially the entire opening 51fC of the case 50C. The first to fourth side portions 51bC to 51eC of the case 50C fit inside the first to fourth side portions 61bC to 61eC of the lid 60C. In this case, for example, the outer surface of the second side portion 51cC of the case 50C has a first fitting portion, and the second side portion 61cC of the lid 60C has a first fitting portion that extends from the lower end parallel to the top plate portion 61aC. The first fitting portion engages with the first fitted portion. The outer surface of the fourth side portion 51eC of the case 50C has a second fitted portion, and the fourth side portion 61eC of the lid 60C has a second fitting portion that extends from its lower end parallel to the top plate portion 61aC. The second fitting portion engages with the second fitted portion.

[0075] The modified lid 60D shown in Figure 16(b) has a top plate portion 61aD with through-holes 61aaD to 61adD for resin injection and a through-hole 61afD for releasing air bubbles. In plan view, the lid 60D has a rectangular shape. The lid 60D covers only a portion of the opening 51fD of the case 50D, not the entire opening. That is, the portion of the opening 51fD indicated by the dotted arrow 80D is not covered by the lid 60D. The second and fourth sides 51cD and 51eD of the case 50D fit inside the second and fourth sides 61cD and 61eD of the lid 60D. In this case, the outer surface of the second side 51cD of the case 50D has a first fitting portion, and the second side 61cD of the lid 60D has a first fitting portion that extends from its lower end parallel to the top plate portion 61aD. The first fitting portion engages with the first fitted portion. The outer surface of the fourth side portion 51eD of the case 50D has a second fitted portion, and the fourth side portion 61eD of the lid 60D has a second fitting portion that extends from its lower end parallel to the top plate portion 61aD. The second fitting portion engages with the second fitted portion.

[0076] The modified lid 60E shown in Figure 16(c) has a top plate portion 61aE with through-holes 61aaE to 61adE for resin injection and a through-hole 61afE for releasing air bubbles. In plan view, the lid 60E has a cross shape. The lid 60E closes only a portion of the opening 51fE of the case 50E, not the entire opening. That is, the portion of the opening 51fE indicated by the dotted arrow 80E is not closed by the lid 60E. The first to fourth sides 51bE to 51eE of the case 50E fit inside the first to fourth sides 61bE to 61eE of the lid 60E. In this case, the outer surface of the second side 51cE of the case 50E has a first fitting portion, and the second side 61cE of the lid 60E has a first fitting portion that extends from the lower end parallel to the top plate portion 61aE. The first fitting portion engages with the first fitted portion. The outer surface of the fourth side portion 51eE of the case 50E has a second fitted portion, and the fourth side portion 61eE of the lid 60E has a second fitting portion that extends from its lower end parallel to the top plate portion 61aE. The second fitting portion engages with the second fitted portion. The outer surface of the first side portion 51bE of the case 50E has a third fitted portion, and the first side portion 61bE of the lid 60E has a third fitting portion that extends from its lower end parallel to the top plate portion 61aE. The third fitting portion engages with the third fitted portion. Furthermore, the outer surface of the third side portion 51dE of the case 50E has a fourth fitting portion, and the third side portion 61dE of the lid 60E has a fourth fitting portion that extends from the lower end parallel to the top plate portion 61aE. The fourth fitting portion engages with the fourth fitting portion.

[0077] The top plate portion 61a of the lids 60, 60A, and 60B in the first to third embodiments has a flat shape, but is not limited to this. For example, it may have the shape shown in Figures 17(a) and (b). Figures 17(a) and (b) are schematic cross-sectional views of the capacitor. For the sake of simplicity in the illustration, the first busbar 20, the second busbar 30, and the insulating member 40 are omitted from the illustration.

[0078] The modified lid 60F shown in Figure 17(a) has a top plate portion 61aF with through-holes 61aaF to 61adF for resin injection. The top plate portion 61aF of the lid 60F also has extensions 64F on its lower surface at three locations, each having a base portion 64aF, a first lower limit indicator portion 64bF, and a second lower limit indicator portion 64cF. The heights of the upper surfaces of the three first lower limit indicator portions 64bF and the three second lower limit indicator portions 64cF are equal. The upper surfaces of the three first lower limit indicator portions 64bF and the three second lower limit indicator portions 64cF serve as indicators for the lower limit of the amount of sealing resin 70 injected. The upper surface near the deepest part of the top plate portion 61aF of the lid 60F serves as an indicator for the upper limit of the amount of sealing resin 70 injected. As shown in Figure 17(a), the top plate portion 61aF of the lid 60F has a curved shape that bulges outwards from the capacitor. The tip of the extension portion 64F is embedded in the sealing resin 70.

[0079] The modified lid 60G shown in Figure 17(b) has a top plate portion 61aG, which includes through-holes 61aaG to 61adG for resin injection. The top plate portion 61aG of the lid 60G also has extensions 64G on its lower surface at three locations, each having a base portion 64aG, a first lower limit indicator portion 64bG, and a second lower limit indicator portion 64cG. The heights of the upper surfaces of the three first lower limit indicator portions 64bG and the three second lower limit indicator portions 64cG are equal. The upper surfaces of the three first lower limit indicator portions 64bG and the three second lower limit indicator portions 64cG serve as indicators for the lower limit of the amount of sealing resin 70 injected. The upper surface near the deepest part of the top plate portion 61aG of the lid 60G serves as an indicator for the upper limit of the amount of sealing resin 70 injected. As shown in Figure 17(b), the top plate portion 61aG of the lid 60G has a curved shape that is recessed inward from the capacitor. The tip of the extension portion 64G is embedded in the sealing resin 70.

[0080] In addition, in the modified lids 60C to 60E shown in Figures 16(a) to (c), the top plates 61aC to 61aE may have a curved shape that bulges outward from the capacitor, or a curved shape that is recessed inward from the capacitor.

[0081] Furthermore, the contents described in the above embodiments and modifications may be combined as appropriate. The present invention is widely applicable to capacitors in which capacitor elements housed in a case are sealed with a sealing resin. [Explanation of Symbols]

[0082] 1.1A: Capacitor 10: Capacitor element 20: First bus bar 30: Second bus bar 40: Insulating material 50: Case 53: First mating part 53a: First lower fitting portion 53b: First upper fitting portion 54: Second mating part 54a: Second lower fitting portion 54b: Second upper fitting portion 60: Lid 61a: Top panel 61aa~61af: Through section 62: First mating part 63: Second mating section 64:Indicator part 64b: First lower limit index section 64c: Second lower limit index section 70: Sealing resin

Claims

1. Capacitor element and A case having an opening and housing the capacitor element, A lid having multiple through-holes, which is positioned over the opening when the capacitor element is housed in the case, A sealing resin injected into the case to seal the capacitor element, It has, The lid has an extension that extends downward from the inner surface between adjacent through portions. At least the tip of the extension is embedded in the sealing resin. Capacitor.

2. The outer surface of the lid is a substantially flat surface. The capacitor according to claim 1.

3. The lid has an outer shape that covers substantially the entire opening. The capacitor according to claim 1 or 2.

4. The extension portion has an indicator portion that serves as an indicator of the resin surface of the sealing resin. The capacitor according to claim 1 or 2.

5. The indicator portion is visible through the through portion. The capacitor according to claim 4.

6. The sealing resin is injected into the case through the through-hole with the lid positioned in the opening. The capacitor according to claim 1 or 2.

7. A lid having multiple through-holes is placed over the opening of a case housing a capacitor element, with an extension portion extending downward from the inner surface between adjacent through-holes. With the lid positioned in the opening, the sealing resin is injected into the case through the through portion until at least the tip of the extension is embedded in the sealing resin, thereby sealing the capacitor element. Capacitor manufacturing method.

8. The outer surface of the lid is a substantially flat surface. A method for manufacturing a capacitor according to claim 7.

9. The lid has an outer shape that covers substantially the entire opening. A method for manufacturing a capacitor according to claim 7 or 8.

10. The extension portion has an indicator portion that serves as an indicator of the resin surface of the sealing resin. A method for manufacturing a capacitor according to claim 7 or 8.

11. The indicator portion is visible through the through portion. A method for manufacturing a capacitor according to claim 10.

Images