JP7698692B2 - Capacitor - Google Patents

Description

The present invention relates to a capacitor.

Patent Document 1 discloses a capacitor in which a capacitor element (1) is housed in a case (2) and filled with resin (3), and external connection terminals (6) (7) are extended outward from the filled resin (3), and the external connection terminals (6) (7) are characterized in that they are provided with constricted portions (10) at the contact points with the resin surface and in the vicinity thereof, the constricted portions having a smaller cross-sectional area than other portions.

Patent Document 2 discloses an electrical component in which an electrical element (21) having a terminal (11) for connection to the outside of the case (31) is stored in a case (31) so that the tip of the terminal (11) for connection protrudes outside the case (31), and the case (31) is filled with resin (32), and a through hole (13) and a protruding portion (14) extending from the inside of the case to the outside are provided near the boundary portion of the terminal (11) for connection from the inside of the case (31) to the outside, and the resin (32) is filled so that each of the through hole (13) and the protruding portion (14) is partially covered with the resin (32).

JP 2007-234708 A JP 2005-85880 A

As disclosed in Patent Documents 1 and 2, a conventional capacitor is known in which a capacitor element electrically connected to a bus bar (exit terminal) is housed inside an exterior case having an opening such that the bus bar protrudes from the opening to the outside, and further, a filling resin is filled inside the exterior case so as to bury the capacitor element.

However, in conventional capacitors, the thermal expansion coefficients of the capacitor element, bus bar, and filling resin are different, which can cause the following problems:

In conventional capacitors, when the temperature of the operating environment changes, the capacitor element expands or contracts, which can cause stress to be applied to the busbar electrically connected to the capacitor element. In this case, in conventional capacitors, the busbar moves in a shearing direction relative to the filled resin surrounding the busbar, which can cause delamination between the busbar and the filled resin due to shear stress at the interface between the busbar and the filled resin, or the stress (pressure) from the busbar moving in the shearing direction can cause cracks in the filled resin.

For example, in conventional capacitors, when used in a high-temperature environment, as the capacitor element expands, the busbar moves toward the opening of the exterior case relative to the filled resin, which can cause shear stress at the interface between the busbar and the filled resin to peel off from each other, or the stress (pressure) from the busbar moving toward the opening of the exterior case can cause cracks in the filled resin.

In response to the above problems, the capacitor described in Patent Document 1 is said to have a structure in which the filling resin that has entered the constricted portion of the external connection terminal strengthens the restriction of the relative movement between the external connection terminal and the filling resin, and as a result, it is possible to prevent cracks from occurring in the portion of the external connection terminal that is pulled out from the sealing resin even if the ambient temperature at the capacitor's installation location changes. However, the capacitor described in Patent Document 1 has room for improvement in terms of further preventing peeling between the external connection terminal and the filling resin, and cracks in the filling resin.

In addition, in the electrical component described in Patent Document 2, by providing a through hole in the connection terminal, it is possible to reduce the amount of expansion of the terminal in the width direction when a thermal shock is applied, and the through hole also divides the deformation area of the resin due to the expansion of the terminal into multiple places, making it possible to disperse the deformation and prevent the occurrence of cracks and peeling of the resin. However, the electrical component described in Patent Document 2 has room for improvement in terms of further suppressing the occurrence of peeling between the connection terminal and the resin, and the occurrence of cracks in the resin.

The present invention has been made to solve the above problems, and aims to provide a capacitor that can suppress the occurrence of peeling between the busbar and the filled resin, and the occurrence of cracks in the filled resin, even when the temperature of the usage environment changes.

In a first aspect, the capacitor of the present invention comprises a capacitor element having an element body and an external electrode provided on a surface of the element body, a bus bar electrically connected to the external electrode, a bottomed cylindrical exterior case with an opening and in which the capacitor element is housed such that the bus bar protrudes from the opening to the outside, and a filling resin filled inside the exterior case so as to embed the capacitor element, wherein a through hole is provided in a portion of the bus bar located between the capacitor element and the opening, the through hole extends in an angle of less than 45° with respect to the opening plane of the opening, and the entire through hole is embedded in the filling resin.

In a second aspect, the capacitor of the present invention comprises a capacitor element having an element body and an external electrode provided on a surface of the element body, a bus bar electrically connected to the external electrode, a bottomed cylindrical exterior case with an opening and in which the capacitor element is housed so that the bus bar protrudes from the opening to the outside, and a filling resin filled inside the exterior case so as to embed the capacitor element, wherein a through hole and a protruding portion protruding from the periphery of the through hole are provided in a portion of the bus bar located between the capacitor element and the opening, the protruding direction in which at least the tip side portion of the protruding portion extends forms an angle of less than 45° with respect to the opening plane of the opening, and at least a portion of the through hole and the entire protruding portion are embedded in the filling resin.

The present invention provides a capacitor that can suppress the occurrence of peeling between the busbar and the filled resin, and the occurrence of cracks in the filled resin, even when the temperature of the usage environment changes.

FIG. 1 is a schematic perspective view of an example of a capacitor according to a first embodiment of the present invention. FIG. 2 is a schematic diagram showing an example of the capacitor shown in FIG. 1 (excluding the filled resin) in an exploded state. FIG. 3 is a schematic perspective view of an example of the capacitor element shown in FIGS. 1 and 2. In FIG. FIG. 4 is a schematic diagram showing an example of a cross-sectional view of the capacitor element shown in FIG. 3 taken along line a1-a2. FIG. 5 is a schematic perspective view of a cross section of the capacitor shown in FIG. FIG. 6 is a schematic diagram showing the capacitor shown in FIG. 5 with the filling resin removed. FIG. 7 is a schematic diagram showing a cross section of the capacitor shown in FIG. 6 as viewed from above. FIG. 8 is a schematic perspective view of an example of a capacitor according to the second embodiment of the present invention. FIG. 9 is a schematic diagram showing an example of the capacitor shown in FIG. 8 (excluding the filled resin) in an exploded state. FIG. 10 is a schematic perspective view of the cross section of the capacitor shown in FIG. FIG. 11 is a schematic diagram showing the capacitor shown in FIG. 10 with the filling resin removed. FIG. 12 is a schematic diagram showing a cross section of the capacitor shown in FIG. 11 as viewed in plan. FIG. 13 is a schematic perspective view of an example of a capacitor according to the third embodiment of the present invention. FIG. 14 is a schematic diagram showing an example of the capacitor shown in FIG. 13 (excluding the filled resin) in an exploded state. FIG. 15 is a schematic perspective view of the cross section of the capacitor shown in FIG. FIG. 16 is a schematic diagram showing the capacitor shown in FIG. 15 with the filling resin removed. FIG. 17 is a schematic diagram showing a cross section of the capacitor shown in FIG. 16 as viewed in plan.

The capacitor of the present invention will be described below. Note that the present invention is not limited to the following configuration, and may be modified as appropriate without departing from the spirit of the present invention. In addition, a combination of multiple individual preferred configurations described below also constitutes the present invention.

The embodiments shown below are merely examples, and it goes without saying that partial substitution or combination of the configurations shown in different embodiments is possible. From embodiment 2 onwards, descriptions of matters common to embodiment 1 will be omitted, and differences will be mainly described. In particular, similar effects resulting from similar configurations will not be mentioned one by one for each embodiment.

In the following description, unless otherwise specified, each embodiment will simply be referred to as the "capacitor of the present invention."

Below, a film capacitor is shown as an example of a capacitor element of the capacitor of the present invention. The capacitor of the present invention can also be applied to capacitor elements other than film capacitors.

The drawings shown below are schematic diagrams, and the dimensions, aspect ratio, and other scales may differ from those of the actual product.

In this specification, unless otherwise specified, terms indicating the relationship between elements (e.g., "parallel," "perpendicular," etc.) and terms indicating the shape of elements do not only mean the literal strict form, but also mean a range that is substantially equivalent, for example, a range that includes a difference of about a few percent.

In a first aspect, the capacitor of the present invention comprises a capacitor element having an element body and an external electrode provided on a surface of the element body, a bus bar electrically connected to the external electrode, a bottomed cylindrical exterior case with an opening and in which the capacitor element is housed such that the bus bar protrudes from the opening to the outside, and a filling resin filled inside the exterior case so as to embed the capacitor element, wherein a through hole is provided in a portion of the bus bar located between the capacitor element and the opening, the through hole extends in an angle of less than 45° with respect to the opening plane of the opening, and the entire through hole is embedded in the filling resin.

[Embodiment 1]
Hereinafter, an example of the first aspect of the capacitor of the present invention will be described as a capacitor of embodiment 1 of the present invention.

Figure 1 is a schematic diagram showing an oblique view of an example of a capacitor according to embodiment 1 of the present invention. Figure 2 is a schematic diagram showing an example of the capacitor shown in Figure 1 (excluding the filled resin) in an exploded state.

The capacitor 1 shown in Figures 1 and 2 has a capacitor element 10, a first bus bar 20a, a second bus bar 20b, an outer case 30, and a filling resin 40.

In FIG. 1 etc., the first direction D1, the second direction D2, and the third direction D3 are perpendicular to each other.

Figure 3 is a schematic diagram showing an example of the capacitor element shown in Figures 1 and 2 in a perspective view. Figure 4 is a schematic diagram showing an example of the capacitor element shown in Figure 3 in a cross-sectional view taken along line a1-a2.

The capacitor element 10 shown in Figures 3 and 4 has a body 11, a first external electrode 12a, and a second external electrode 12b.

The element body 11 is a wound body in which the first metallized film 13a and the second metallized film 13b are wound in a stacked state in the first direction D1. In other words, the capacitor element 10 is a wound-type film capacitor in which the metallized films are stacked and wound.

The capacitor element 10 may be a laminated film capacitor (e.g., rectangular) in which metallized films are laminated.

The element body 11 has a first end face 11a and a second end face 11b facing the third direction D3.

The element body 11 has a side surface 11c that extends in the third direction D3 so as to connect the peripheries of the first end surface 11a and the second end surface 11b.

In terms of reducing the height of the capacitor element 10, it is preferable that the cross-sectional shape of the element body 11 be flat when viewed in a cross section perpendicular to the winding axis direction of the element body 11 (third direction D3 in Figures 3 and 4). Specifically, it is preferable that the cross-sectional shape of the element body 11 is pressed into a flat shape such as an ellipse or oval, and that the cross-sectional shape of the element body 11 is thinner than when it is a perfect circle.

Whether the element has been pressed to have a flat cross-sectional shape can be confirmed, for example, by checking whether or not there are press marks on the element.

The capacitor element 10 may have a cylindrical winding axis. The winding axis is disposed on the central axis of the first metallized film 13a and the second metallized film 13b in the wound state, and serves as the winding axis when winding the first metallized film 13a and the second metallized film 13b.

The first metallized film 13a has a first dielectric film 14a and a first metal layer 15a.

The first dielectric film 14a has a first main surface 14aa and a second main surface 14ab facing each other in the first direction D1.

The first metal layer 15a is provided on the first main surface 14aa of the first dielectric film 14a. Specifically, the first metal layer 15a is provided on the first main surface 14aa of the first dielectric film 14a so as to reach one side edge of the first dielectric film 14a in the third direction D3, but not to reach the other side edge of the first dielectric film 14a.

The second metallized film 13b has a second dielectric film 14b and a second metal layer 15b.

The second dielectric film 14b has a first main surface 14ba and a second main surface 14bb that face each other in the first direction D1.

The second metal layer 15b is provided on the first main surface 14ba of the second dielectric film 14b. Specifically, the second metal layer 15b is provided on the first main surface 14ba of the second dielectric film 14b so as not to reach one side edge of the second dielectric film 14b in the third direction D3, but to reach the other side edge of the second dielectric film 14b.

In the element body 11, the adjacent first metallized films 13a and second metallized films 13b are shifted in the third direction D3 so that the end of the first metal layer 15a that reaches the side edge of the first dielectric film 14a is exposed to the first end face 11a of the element body 11, and the end of the second metal layer 15b that reaches the side edge of the second dielectric film 14b is exposed to the second end face 11b of the element body 11. That is, in the adjacent first metallized films 13a and second metallized films 13b, the first metallized film 13a protrudes toward the first external electrode 12a relative to the second metallized film 13b. In addition, in the adjacent first metallized films 13a and second metallized films 13b, the second metallized film 13b protrudes toward the second external electrode 12b relative to the first metallized film 13a. In this state, the first metal layer 15a is connected to the first external electrode 12a and is not connected to the second external electrode 12b. Also, the second metal layer 15b is connected to the second external electrode 12b and is not connected to the first external electrode 12a.

In the element body 11, the adjacent first metallized film 13a and second metallized film 13b are shifted in the third direction D3 as described above, so that in the adjacent first dielectric film 14a and second dielectric film 14b, the first dielectric film 14a having the first metal layer 15a on the first main surface 14aa protrudes toward the first external electrode 12a side relative to the second dielectric film 14b having the first metal layer 15a not provided on the main surface. In addition, in the adjacent first dielectric film 14a and second dielectric film 14b, the second dielectric film 14b having the second metal layer 15b on the first main surface 14ba protrudes toward the second external electrode 12b side relative to the first dielectric film 14a having the second metal layer 15b not provided on the main surface.

The element body 11 is formed by winding the first metallized film 13a and the second metallized film 13b in a stacked state in the first direction D1, and therefore can be said to include the first dielectric film 14a, the first metal layer 15a, the second dielectric film 14b, and the second metal layer 15b in the first direction D1. It can also be said that the element body 11 is a wound body formed by winding the first dielectric film 14a, the first metal layer 15a, the second dielectric film 14b, and the second metal layer 15b in the first direction D1.

In the element body 11, the first main surface 14aa of the first dielectric film 14a and the second main surface 14bb of the second dielectric film 14b face each other in the first direction D1, and the second main surface 14ab of the first dielectric film 14a and the first main surface 14ba of the second dielectric film 14b face each other in the first direction D1. Thus, in the element body 11, the first metallized film 13a and the second metallized film 13b are wound in a state in which they are stacked in the first direction D1. In other words, in the element body 11, the first metallized film 13a and the second metallized film 13b are wound in a state in which they are stacked in the first direction D1, so that the second metallized film 13b is on the inside of the first metallized film 13a, specifically, the first metal layer 15a is on the inside of the first dielectric film 14a, and the second metal layer 15b is on the inside of the second dielectric film 14b. That is, in the element body 11, the first metal layer 15a and the second metal layer 15b face each other with the first dielectric film 14a or the second dielectric film 14b sandwiched between them.

The first metal layer 15a may be provided with a fuse portion. The fuse portion provided in the first metal layer 15a is, for example, a portion of the first metal layer 15a that connects a divided electrode portion in which a portion facing the second metal layer 15b is divided into multiple portions, and an electrode portion that does not face the second metal layer 15b. Examples of electrode patterns of the first metal layer 15a provided with a fuse portion include the electrode patterns disclosed in JP 2004-363431 A and JP 5-251266 A.

The second metal layer 15b may also be provided with a fuse portion, similar to the first metal layer 15a.

The first dielectric film 14a may contain a curable resin as a main component.

In this specification, the term "main component" refers to the component with the highest weight percentage, preferably greater than 50% by weight.

The curable resin may be a thermosetting resin or a photocurable resin.

In this specification, thermosetting resin means a resin that can be cured by heat, but the curing method is not limited. Therefore, thermosetting resin also includes resins that can be cured by methods other than heat (e.g., light, electron beam, etc.) as long as they are heat-curable. Also, depending on the material, a reaction may be initiated by the reactivity of the material itself, and resins that proceed to cure without necessarily being subjected to heat from the outside are also considered to be thermosetting resins. The same applies to photocurable resins, and as long as they are light-curable, they also include resins that can be cured by methods other than light (e.g., heat, etc.).

The curable resin is preferably made of a cured product of a first organic material having a hydroxyl group (OH group) and a second organic material having an isocyanate group (NCO group). In this case, the curable resin is made of a cured product having a urethane bond obtained by reacting the hydroxyl group of the first organic material with the isocyanate group of the second organic material.

The presence of urethane bonds in the dielectric film can be confirmed by analysis using a Fourier transform infrared spectrophotometer (FT-IR).

When the curable resin is obtained by the above-mentioned reaction, uncured portions of the starting material may remain in the first dielectric film 14a. For example, the first dielectric film 14a may contain at least one of a hydroxyl group and an isocyanate group. In this case, the first dielectric film 14a may contain either a hydroxyl group or an isocyanate group, or may contain both a hydroxyl group and an isocyanate group.

The presence of hydroxyl groups and/or isocyanate groups in the dielectric film can be confirmed by FT-IR analysis.

Examples of the first organic material include phenoxy resin, polyvinyl acetoacetal resin, polyvinyl butyral resin, etc.

As the first organic material, multiple types of organic materials may be used in combination.

Examples of the second organic material include aromatic polyisocyanates such as diphenylmethane diisocyanate (MDI) and tolylene diisocyanate (TDI), and aliphatic polyisocyanates such as hexamethylene diisocyanate (HDI). As the second organic material, at least one modified product of these polyisocyanates may be used, or a mixture of at least one of these polyisocyanates and its modified product may be used.

As the second organic material, multiple types of organic materials may be used in combination.

The first dielectric film 14a may contain a thermoplastic resin as a main component.

Examples of thermoplastic resins include polypropylene resin, polyethersulfone resin, polyetherimide resin, polyarylate resin, etc.

The first dielectric film 14a may contain additives to impart various functions.

Additives include, for example, leveling agents to impart smoothness.

The additive preferably has a functional group that reacts with a hydroxyl group and/or an isocyanate group and forms part of the crosslinked structure of the cured product. Examples of such additives include resins having at least one functional group selected from the group consisting of a hydroxyl group, an epoxy group, a silanol group, and a carboxyl group.

The second dielectric film 14b may contain a thermosetting resin as a main component, a photocurable resin as a main component, or a thermoplastic resin as a main component, similar to the first dielectric film 14a. The second dielectric film 14b may also contain an additive, similar to the first dielectric film 14a.

The compositions of the first dielectric film 14a and the second dielectric film 14b may be different from each other, but are preferably the same.

The thickness of the first dielectric film 14a and the second dielectric film 14b is preferably 1 μm or more and 10 μm or less, and more preferably 3 μm or more and 5 μm or less.

The thicknesses of the first dielectric film 14a and the second dielectric film 14b may be different from each other, but are preferably the same.

The thickness of the dielectric film is measured using an optical thickness gauge.

The first dielectric film 14a and the second dielectric film 14b are each preferably produced by forming a resin solution containing the resin material as described above into a film and then curing it by heat treatment.

Examples of materials that can be used to form the first metal layer 15a and the second metal layer 15b include metals such as aluminum, zinc, titanium, magnesium, tin, and nickel.

The compositions of the first metal layer 15a and the second metal layer 15b may be different from each other, but are preferably the same.

The thickness of the first metal layer 15a and the second metal layer 15b is preferably 5 nm or more and 40 nm or less.

The thicknesses of the first metal layer 15a and the second metal layer 15b may be different from each other, but are preferably the same.

The thickness of the metal layer is measured by observing a cross section of the metallized film along the first direction using a transmission electron microscope (TEM).

The first metal layer 15a and the second metal layer 15b are preferably formed by depositing a metal such as that described above onto the major surfaces of the first dielectric film 14a and the second dielectric film 14b, respectively.

Although the above describes an embodiment in which the element 11 includes two metallized films, the element 11 may include one metallized film. For example, the element 11 may include a metallized film having a first dielectric film 14a in which a first metal layer 15a is provided on the first main surface 14aa and a second metal layer 15b is provided on the second main surface 14ab, and a second dielectric film 14b in which no metal layer is provided. Alternatively, the element 11 may include a metallized film having a second dielectric film 14b in which a first metal layer 15a is provided on the second main surface 14bb and a second metal layer 15b is provided on the first main surface 14ba, and a first dielectric film 14a in which no metal layer is provided.

The first external electrode 12a is provided on the surface of the element body 11. In the example shown in Figures 3 and 4, the first external electrode 12a is provided on the first end surface 11a of the element body 11. The first external electrode 12a is connected to the first metal layer 15a by contacting the end of the first metal layer 15a exposed on the first end surface 11a of the element body 11. On the other hand, the first external electrode 12a is not connected to the second metal layer 15b.

The second external electrode 12b is provided at a position on the surface of the element body 11 away from the first external electrode 12a. In the example shown in Figures 3 and 4, the second external electrode 12b is provided on the second end face 11b of the element body 11. The second external electrode 12b is connected to the second metal layer 15b by contacting the end of the second metal layer 15b exposed on the second end face 11b of the element body 11. On the other hand, the second external electrode 12b is not connected to the first metal layer 15a.

Examples of materials that can be used to form the first external electrode 12a and the second external electrode 12b include metals such as zinc, aluminum, tin, and zinc-aluminum alloys.

The compositions of the first external electrode 12a and the second external electrode 12b may be different from each other, but are preferably the same.

The first external electrode 12a and the second external electrode 12b are preferably formed by spraying a metal such as that described above onto the first end surface 11a and the second end surface 11b of the element body 11, respectively.

As shown in FIG. 2, the first bus bar 20a is electrically connected to the first external electrode 12a. The first bus bar 20a may be connected to the first external electrode 12a via a joining member such as solder, or may be welded.

The first busbar 20a has a first main surface 20aa and a second main surface 20ab that face each other in the thickness direction.

The first bus bar 20a preferably covers the surface of the capacitor element 10 on which the first external electrode 12a and the second external electrode 12b are not provided. In the example shown in FIG. 2, the first bus bar 20a covers the side surface 11c of the body 11 of the capacitor element 10 on which the first external electrode 12a and the second external electrode 12b are not provided (in FIG. 2, they overlap in the first direction D1). In this case, the equivalent series inductance (ESL) of the capacitor 1 is likely to decrease.

The first bus bar 20a is preferably located away from the surface of the capacitor element 10 on which the first external electrode 12a and the second external electrode 12b are not provided. In the examples shown in Figures 5, 6, and 7 described below, the first bus bar 20a is located away from the side surface 11c of the body 11 of the capacitor element 10 on which the first external electrode 12a and the second external electrode 12b are not provided. In this case, it becomes easier to ensure insulation between the body 11 and the first bus bar 20a.

When the first bus bar 20a is located away from a surface of the capacitor element 10 on which the first external electrode 12a and the second external electrode 12b are not provided, it is preferable that a filling resin 40 is filled between the first bus bar 20a and that surface of the capacitor element 10.

As shown in FIG. 2, the second bus bar 20b is electrically connected to the second external electrode 12b. The second bus bar 20b may be connected to the second external electrode 12b via a joining member such as solder, or may be welded.

The second busbar 20b is electrically connected to the second external electrode 12b instead of the first external electrode 12a, and therefore has a different polarity than the first busbar 20a, which is electrically connected to the first external electrode 12a.

The second busbar 20b has a first main surface 20ba and a second main surface 20bb that face each other in the thickness direction.

The second busbar 20b preferably covers the surface of the capacitor element 10 on which the first external electrode 12a and the second external electrode 12b are not provided. In the example shown in FIG. 2, the second busbar 20b covers the side surface 11c of the body 11 of the capacitor element 10 on which the first external electrode 12a and the second external electrode 12b are not provided (in FIG. 2, they overlap in the first direction D1). In this case, the equivalent series inductance of the capacitor 1 is likely to decrease.

It is preferable that the second bus bar 20b is separated from the surface of the capacitor element 10 on which the first external electrode 12a and the second external electrode 12b are not provided. In the examples shown in Figures 5, 6, and 7 described below, the second bus bar 20b is separated from the side surface 11c of the body 11 of the capacitor element 10 on which the first external electrode 12a and the second external electrode 12b are not provided. In this case, it is easier to ensure insulation between the body 11 and the second bus bar 20b.

When the second busbar 20b is located away from a surface of the capacitor element 10 on which the first external electrode 12a and the second external electrode 12b are not provided, it is preferable that a filling resin 40 is filled between the second busbar 20b and that surface of the capacitor element 10.

The first bus bar 20a and the second bus bar 20b are preferably shaped like a plate. In this case, the first bus bar 20a and the second bus bar 20b may each have a shape with a partially bent portion.

The shapes of the first busbar 20a and the second busbar 20b may be the same or different.

The constituent material of the first busbar 20a and the second busbar 20b may be, for example, a metal such as copper, oxygen-free copper, aluminum, or an alloy containing at least one of these metals. Among these, the constituent material of the first busbar 20a and the second busbar 20b is preferably copper or oxygen-free copper. When the constituent material of the first busbar 20a and the second busbar 20b is a copper-based material, for example, oxygen-free copper (copper: 99.96% by weight or more), tough pitch copper (copper: 99.90% by weight or more), phosphorus deoxidized copper (copper: 99.90% by weight or more, phosphorus: 0.015% by weight or more, 0.040% by weight or less), etc. may be used.

The constituent materials of the first bus bar 20a and the second bus bar 20b may be the same or different.

The thickness of the first bus bar 20a and the second bus bar 20b may be the same or different.

The first busbar 20a and the second busbar 20b may overlap in part in close proximity. In the example shown in FIG. 2, the first busbar 20a and the second busbar 20b overlap in part in close proximity to the second main surface 20ab and the second main surface 20bb. In the example shown in FIG. 2, a gap of a predetermined distance is provided between the first busbar 20a and the second busbar 20b, specifically, between the second main surface 20ab of the first busbar 20a and the second main surface 20bb of the second busbar 20b.

When parts of the first busbar 20a and the second busbar 20b overlap each other closely, specifically, when a gap of a predetermined distance is provided between the first busbar 20a and the second busbar 20b, it is preferable that an insulating sheet (not shown) that forms a layered structure together with the first busbar 20a and the second busbar 20b is sandwiched between the first busbar 20a and the second busbar 20b. Specifically, it is preferable that the first busbar 20a, the insulating sheet, and the second busbar 20b are stacked in order to form a layered structure. In this case, the insulating sheet ensures insulation between the first busbar 20a and the second busbar 20b.

In this specification, insulating sheets also include forms such as insulating paper, insulating plates, and insulating films.

Examples of materials that can be used to make the insulating sheet include resin.

As shown in Figs. 1 and 2, the exterior case 30 is a bottomed cylindrical shape with an opening 31. Specifically, the exterior case 30 is a bottomed cylindrical shape with an opening 31 at one end in the first direction D1.

In the example shown in Figures 1 and 2, the exterior case 30 has a bottom 32 that faces the opening 31 in the first direction D1, and a side wall 33 that extends from the bottom 32 toward the opening 31 in the first direction D1.

The capacitor element 10 is housed inside the exterior case 30 so that the first bus bar 20a and the second bus bar 20b protrude from the opening 31 toward the outside.

It is preferable that the capacitor element 10 is stored inside the outer case 30 so as to be away from the inner surface of the outer case 30.

Examples of the exterior case 30 include a resin case, a metal case, etc.

When the exterior case 30 is a resin case, examples of the resin that constitutes the resin case include liquid crystal polymer (LCP), polyphenylene sulfide resin, polybutylene terephthalate resin, etc. Among these, it is preferable that the resin case contains a liquid crystal polymer.

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. In addition to p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid groups, liquid crystal polymers formed from polycondensates using various components such as phenol, phthalic acid, and ethylene terephthalate can also be used. Liquid crystal polymers can also be classified into types I, II, and III, but the material used is the same as the liquid crystal polymer formed from the above-mentioned components.

It is preferable that the resin case further contains an inorganic filler in addition to the liquid crystal polymer.

The inorganic filler contained in the resin case can be a material that is stronger than the liquid crystal polymer. The inorganic filler is preferably a material that has a higher melting point than the liquid crystal polymer, and more preferably a material with a melting point of 680°C or higher.

The shape of the inorganic filler is not particularly limited, and examples include a shape having a longitudinal direction such as a fiber shape or a plate shape. As an inorganic filler of such a shape, multiple types of inorganic materials may be used in combination. It is preferable that the resin case contains at least one of a fibrous inorganic material and a plate-shaped inorganic material as the inorganic filler.

In this specification, a filler being fibrous means that the relationship between the longitudinal dimension in the longitudinal direction and the cross-sectional diameter in a cross section perpendicular to the longitudinal direction is longitudinal dimension/cross-sectional diameter ≧5 (i.e., the aspect ratio is 5:1 or more). Here, the cross-sectional diameter is the longest distance between two points on the circumference of the cross section. If the cross-sectional diameter varies in the longitudinal direction, the measurement is taken at the point where the cross-sectional diameter is largest.

In this specification, a filler being plate-like means that the relationship between the cross-sectional diameter of the face with the largest projected area and the maximum height in the direction perpendicular to this cross-section is cross-sectional diameter/maximum height ≧ 3.

It is preferable that at least a portion of the inorganic filler has a portion oriented in the direction from the bottom 32 toward the opening 31 in the sidewall 33 and a portion oriented in the outer circumferential direction of the sidewall 33, and is dispersed inside the exterior case 30.

The size of the inorganic filler is preferably 5 μm or more in diameter and 50 μm or more in length.

It is preferable that the inorganic filler be dispersed throughout the exterior case 30 without agglomerating.

Examples of inorganic fillers include inorganic materials such as fibrous glass filler, plate-like talc or mica. Of these, it is preferable for the inorganic filler to contain fibrous glass filler as the main component.

Even if the resin case contains another resin (e.g., polyphenylene sulfide resin) instead of the liquid crystal polymer, it is preferable that the resin case further contains an inorganic filler as described above.

The resin case is manufactured by a method such as injection molding.

When the exterior case 30 is a metal case, examples of the metal constituting the metal case include simple metals such as aluminum, magnesium, iron, stainless steel, and copper, and alloys containing at least one of these simple metals. Of these, it is preferable that the metal case contains aluminum or an aluminum alloy.

The metal case is manufactured, for example, by a method such as impact molding.

As shown in FIG. 1, the filled resin 40 is filled inside the exterior case 30 so as to embed the capacitor element 10. When the filled resin 40 is filled inside the exterior case 30 in this manner, the capacitor element 10 is held inside the exterior case 30.

When the capacitor element 10 is stored inside the exterior case 30 so as to be away from the inner surface of the exterior case 30, it is preferable that the filling resin 40 is filled between the capacitor element 10 and the exterior case 30, specifically, between the outer surface of the capacitor element 10 and the inner surface of the exterior case 30. Furthermore, it is preferable that the filling resin 40 is filled inside the exterior case 30, not only between the capacitor element 10 and the exterior case 30, but also in the region from the opening 31 to the capacitor element 10.

As the filling resin 40, it is preferable to appropriately select a resin with low moisture permeability from the viewpoint of suppressing the infiltration of moisture into the capacitor element 10, and examples thereof include epoxy resin, silicone resin, urethane resin, etc. Examples of the hardener for the epoxy resin include an amine hardener, an imidazole hardener, etc.

The filling resin 40 may be the resin described above alone, but in order to improve strength, a resin to which a reinforcing agent has been added may also be used. Examples of reinforcing agents include silica and alumina.

From the viewpoint of suppressing the infiltration of moisture into the capacitor element 10, it is preferable that the thickness of the filling resin 40 at the opening 31 is large. The thickness of the filling resin 40 at the opening 31 is preferably sufficiently large within the range that allows for the volume (physical size) of the entire capacitor 1, and specifically, is preferably 2 mm or more, and more preferably 4 mm or more. In particular, it is preferable that the thickness of the filling resin 40 relative to the capacitor element 10 is made larger on the opening 31 side than on the bottom 32 side by arranging the capacitor element 10 closer to the bottom 32 side than the opening 31 side inside the exterior case 30.

The thickness of the filling resin 40 is measured, for example, using a soft X-ray device if it is in a non-destructive state, and using a length measuring device such as a caliper if it is in a destructive state.

The relationship between the height of the outer case 30 and the height of the filled resin 40 in the first direction D1 is such that the thickness of the filled resin 40 at the opening 31 is as large as possible, and may be up to a position on the inside of the outer case 30, may be nearly to the top, or may overflow slightly due to surface tension.

Figure 5 is a schematic diagram showing an oblique cross-section of the capacitor shown in Figure 1. Figure 6 is a schematic diagram showing the capacitor shown in Figure 5 with the filling resin removed. Figure 7 is a schematic diagram showing the cross-section of the capacitor shown in Figure 6 in a plan view.

As shown in Figures 5, 6, and 7, the first bus bar 20a has a first through hole 21aa in a portion located between the capacitor element 10 and the opening 31.

The first through hole 21aa has a first end 21aaa located on the first main surface 20aa side of the first bus bar 20a and a second end 21aab located on the second main surface 20ab side of the first bus bar 20a.

As shown in FIG. 7, the through-hole direction DHaa in which the first through-hole 21aa extends (hereinafter also referred to as the through-hole direction DHaa of the first through-hole 21aa) forms an angle of less than 45° with respect to the opening surface 31s of the opening 31. Specifically, the through-hole direction DHaa of the first through-hole 21aa forms an angle of 0° or more and less than 45° with respect to the opening surface 31s of the opening 31.

The through-hole direction DHaa of the first through-hole 21aa is determined by the direction of extension of a straight line connecting the center of gravity of the first end 21aaa of the first through-hole 21aa when viewed in a plane and the center of gravity of the second end 21aab of the first through-hole 21aa when viewed in a plane. For example, as shown in FIG. 2, when the planar shape of the first through-hole 21aa (in FIG. 2, the planar shape when viewed in a plane from the third direction D3) is rectangular, the through-hole direction DHaa of the first through-hole 21aa is determined by the direction of extension of a straight line connecting the intersection of the diagonal of the first end 21aaa (rectangle) of the first through-hole 21aa when viewed in a plane and the intersection of the diagonal of the second end 21aab (rectangle) of the first through-hole 21aa when viewed in a plane. The through-hole directions of the other through-holes are determined in the same manner.

As shown in Figures 5 and 6, the entire first through hole 21aa is embedded in the filling resin 40.

In the capacitor 1, the entire first through hole 21aa is embedded in the filled resin 40, and the first bus bar 20a is fixed by the filled resin 40 that has entered the first through hole 21aa. Furthermore, in the capacitor 1, the penetration direction DHaa of the first through hole 21aa forms an angle of less than 45° with respect to the opening surface 31s of the opening 31, and therefore the movement of the first bus bar 20a that shifts in the shear direction relative to the filled resin 40 (particularly, toward the opening surface 31s of the opening 31 or the opposite side to the opening surface 31s relative to the filled resin 40) caused by the expansion or contraction of the capacitor element 10 when the temperature of the usage environment changes is suppressed by the filled resin 40 that has entered the first through hole 21aa. As a result, in the capacitor 1, the occurrence of peeling between the first bus bar 20a and the filled resin 40 due to shear stress at the interface between the first bus bar 20a and the filled resin 40, and the occurrence of cracks in the filled resin 40 due to stress (pressure) from the first bus bar 20a moving in the shear direction are suppressed.

In contrast, if the angle that the through-hole 21aa's through-hole direction DHaa makes with respect to the opening surface 31s of the opening 31 is 45° or more, particularly close to 90°, the filled resin 40 that has entered the first through-hole 21aa is less likely to function to suppress the movement of the first bus bar 20a that shifts in the shear direction relative to the filled resin 40 (particularly, toward the opening surface 31s of the opening 31 or the opposite side to the opening surface 31s relative to the filled resin 40). Therefore, if the through-hole direction DHaa of the first through-hole 21aa forms an angle of 45° or more with respect to the opening surface 31s of the opening 31, the movement of the first bus bar 20a that shifts in the shear direction relative to the filled resin 40 is less likely to be suppressed by the filled resin 40 that has entered the first through-hole 21aa.

In the capacitor described in Patent Document 1, as shown in FIG. 1(a) and FIG. 1(b) of Patent Document 1, the through hole 11 provided in the external connection terminal 6 (external connection terminal 7) is embedded in the resin 3. However, in the capacitor described in Patent Document 1, the penetration direction in which the through hole 11 extends is perpendicular to the opening surface of the opening of the case 2, so that it is difficult to suppress the movement of the external connection terminal 6 (external connection terminal 7) that shifts in the shear direction relative to the resin 3 (particularly, toward or away from the opening surface of the opening of the case 2 relative to the resin 3) caused by the expansion or contraction of the capacitor element 1 when the temperature of the usage environment changes.

In addition, in the electrical component described in Patent Document 2, as shown in FIG. 4 of Patent Document 2, the through hole 13 provided in the connection terminal 11 is embedded in the resin 32. However, in the electrical component described in Patent Document 2, only a portion of the through hole 13 is embedded in the resin 32, so that it is difficult to suppress the movement of the connection terminal 11 that shifts in the shear direction relative to the resin 32 (particularly, toward the opening surface side of the opening of the case 31 or the opposite side to the opening surface relative to the resin 32) caused by the expansion or contraction of the electrical element 21 when the temperature of the usage environment changes.

For these reasons, compared to, for example, the capacitor described in Patent Document 1 and the electrical component described in Patent Document 2, the capacitor 1 has the advantageous effect of "suppressing the occurrence of peeling between the busbar and the filled resin, and the occurrence of cracks in the filled resin, even if the temperature of the usage environment changes."

From the viewpoint of enhancing the above-mentioned effects of the capacitor 1, it is preferable that the penetration direction DHaa of the first through hole 21aa is parallel to the opening surface 31s of the opening 31, as shown in FIG. 7.

In the example shown in FIG. 7, the through-hole direction DHaa of the first through-hole 21aa is parallel to the third direction D3. Also, in the example shown in FIG. 7, the opening surface 31s of the opening 31 is parallel to the third direction D3. Therefore, in the example shown in FIG. 7, the through-hole direction DHaa of the first through-hole 21aa is parallel to the opening surface 31s of the opening 31. In other words, in the example shown in FIG. 7, the through-hole direction DHaa of the first through-hole 21aa forms an angle of 0° with respect to the opening surface 31s of the opening 31.

The penetration direction DHaa of the first through hole 21aa may form an angle greater than 0° and less than 45° with respect to the opening surface 31s of the opening 31.

The penetration direction DHaa of the first through hole 21aa may be parallel to the thickness direction of the first bus bar 20a (the third direction D3 in FIG. 7) or may not be parallel to the thickness direction of the first bus bar 20a (it may be inclined with respect to the thickness direction of the first bus bar 20a) as long as it forms an angle of less than 45° with respect to the opening surface 31s of the opening 31.

When the penetration direction DHaa of the first through hole 21aa is parallel to the thickness direction of the first bus bar 20a, it is perpendicular to the first main surface 20aa or the second main surface 20ab of the first bus bar 20a.

If the penetration direction DHaa of the first through hole 21aa is not parallel to the thickness direction of the first bus bar 20a (if it is inclined relative to the thickness direction of the first bus bar 20a), it is not perpendicular to the first main surface 20aa or the second main surface 20ab of the first bus bar 20a (if it is inclined relative to the first main surface 20aa or the second main surface 20ab of the first bus bar 20a).

As shown in FIG. 7, it is preferable that the surface of the first busbar 20a on which the first through hole 21aa (as well as the first through hole 21ab described below) is provided is perpendicular to the opening surface 31s of the opening 31.

In the example shown in FIG. 7, the first main surface 20aa and the second main surface 20ab of the first busbar 20a in which the first through hole 21aa is provided are perpendicular to the opening surface 31s of the opening 31.

In addition, if the penetration direction DHaa of the first through hole 21aa forms an angle of less than 45° with respect to the opening surface 31s of the opening 31, the first main surface 20aa and the second main surface 20ab of the first bus bar 20a in which the first through hole 21aa is provided do not have to be perpendicular to the opening surface 31s of the opening 31.

As shown in Figures 5, 6, and 7, the first bus bar 20a further includes a first through hole 21ab in a portion located between the capacitor element 10 and the opening 31.

The first through hole 21ab has a first end 21aba located on the first main surface 20aa side of the first busbar 20a and a second end 21abb located on the second main surface 20ab side of the first busbar 20a.

As shown in FIG. 7, the through-hole direction DHab in which the first through-hole 21ab extends (hereinafter also referred to as the through-hole direction DHab of the first through-hole 21ab) forms an angle of less than 45° with respect to the opening surface 31s of the opening 31.

As shown in Figures 5 and 6, the entire first through hole 21ab is embedded in the filling resin 40.

In the capacitor 1, the penetration direction DHab of the first through hole 21ab forms an angle of less than 45° with respect to the opening surface 31s of the opening 31, and the entire first through hole 21ab is embedded in the filled resin 40. As a result, in the same manner as the mechanism described above, even if the temperature of the usage environment changes, peeling between the first bus bar 20a and the filled resin 40 and cracks in the filled resin 40 are suppressed.

The characteristics of the first through hole 21ab (e.g., the penetration direction DHab of the first through hole 21ab) are similar to the characteristics of the first through hole 21aa, including the points described above.

As shown in Figures 5, 6, and 7, the second busbar 20b has a second through hole 21ba in a portion located between the capacitor element 10 and the opening 31.

The second through hole 21ba has a first end 21baa located on the first main surface 20ba side of the second busbar 20b, and a second end 21bab located on the second main surface 20bb side of the second busbar 20b.

As shown in FIG. 7, the through-hole direction DHba in which the second through-hole 21ba extends (hereinafter also referred to as the through-hole direction DHba of the second through-hole 21ba) forms an angle of less than 45° with respect to the opening surface 31s of the opening 31.

As shown in Figures 5 and 6, the entire second through hole 21ba is embedded in the filling resin 40.

In the capacitor 1, the penetration direction DHba of the second through hole 21ba forms an angle of less than 45° with respect to the opening surface 31s of the opening 31, and the entire second through hole 21ba is embedded in the filled resin 40. As a result, in the same manner as the mechanism described above, even if the temperature of the usage environment changes, peeling between the second bus bar 20b and the filled resin 40 and cracks in the filled resin 40 are suppressed.

The characteristics of the second through hole 21ba (e.g., the penetration direction DHba of the second through hole 21ba) are similar to the characteristics of the first through hole 21aa, including the points described above.

As shown in FIG. 7, it is preferable that the surface of the second busbar 20b on which the second through hole 21ba (as well as the second through hole 21bb described below) is provided is perpendicular to the opening surface 31s of the opening 31.

In the example shown in FIG. 7, the first main surface 20ba and the second main surface 20bb of the second busbar 20b in which the second through hole 21ba is provided are perpendicular to the opening surface 31s of the opening 31.

In addition, if the penetration direction DHba of the second through hole 21ba forms an angle of less than 45° with respect to the opening surface 31s of the opening 31, the first main surface 20ba and the second main surface 20bb of the second bus bar 20b in which the second through hole 21ba is provided do not have to be perpendicular to the opening surface 31s of the opening 31.

As shown in Figures 5, 6, and 7, the second busbar 20b has a second through hole 21bb in a portion located between the capacitor element 10 and the opening 31.

The second through hole 21bb has a first end 21bba located on the first main surface 20ba side of the second busbar 20b, and a second end 21bbb located on the second main surface 20bb side of the second busbar 20b.

As shown in FIG. 7, the penetration direction DHbb in which the second through hole 21bb extends (hereinafter also referred to as the penetration direction DHbb of the second through hole 21bb) forms an angle of less than 45° with respect to the opening surface 31s of the opening 31.

As shown in Figures 5 and 6, the entire second through hole 21bb is embedded in the filling resin 40.

In the capacitor 1, the penetration direction DHbb of the second through hole 21bb forms an angle of less than 45° with respect to the opening surface 31s of the opening 31, and the entire second through hole 21bb is embedded in the filling resin 40. As a result, in the same manner as the mechanism described above, even if the temperature of the usage environment changes, peeling between the second bus bar 20b and the filling resin 40 and cracks in the filling resin 40 are suppressed.

The characteristics of the second through hole 21bb (e.g., the penetration direction DHbb of the second through hole 21bb) are similar to the characteristics of the first through hole 21aa, including the points described above.

2, 6, and 7, in the region where the first busbar 20a and the second busbar 20b overlap, it is preferable that at least a part of the first through hole 21aa and at least a part of the second through hole 21ba overlap and communicate with each other. In this case, in the capacitor 1, the first busbar 20a and the second busbar 20b are more firmly fixed by the filled resin 40 that has entered the first through hole 21aa and the second through hole 21ba, so that even if the temperature of the usage environment changes, the occurrence of peeling between the first busbar 20a and the filled resin 40, the occurrence of peeling between the second busbar 20b and the filled resin 40, and the occurrence of cracks in the filled resin 40 are more suppressed.

2, 6, and 7, in the region where the first bus bar 20a and the second bus bar 20b overlap, the entire first through hole 21aa and the entire second through hole 21ba overlap and communicate with each other, but the entire first through hole 21aa and a part of the second through hole 21ba may overlap and communicate with each other, a part of the first through hole 21aa and the entire second through hole 21ba may overlap and communicate with each other, or a part of the first through hole 21aa and a part of the second through hole 21ba may overlap and communicate with each other.

2, 6, and 7, in the region where the first busbar 20a and the second busbar 20b overlap, it is preferable that at least a part of the first through hole 21ab and at least a part of the second through hole 21bb overlap and communicate with each other. In this case, in the capacitor 1, the first busbar 20a and the second busbar 20b are more firmly fixed by the filled resin 40 that has entered the first through hole 21ab and the second through hole 21bb, so that even if the temperature of the usage environment changes, the occurrence of peeling between the first busbar 20a and the filled resin 40, the occurrence of peeling between the second busbar 20b and the filled resin 40, and the occurrence of cracks in the filled resin 40 are more suppressed.

2, 6, and 7, in the region where the first bus bar 20a and the second bus bar 20b overlap, the entire first through hole 21ab and the entire second through hole 21bb overlap and communicate with each other, but the entire first through hole 21ab and a part of the second through hole 21bb may overlap and communicate with each other, or a part of the first through hole 21ab and the entire second through hole 21bb may overlap and communicate with each other, or a part of the first through hole 21ab and a part of the second through hole 21bb may overlap and communicate with each other.

The planar shapes of the first through hole 21aa, the first through hole 21ab, the second through hole 21ba, and the second through hole 21bb (in FIG. 2, the planar shapes when viewed from the third direction D3) are not particularly limited, and examples include rectangular shapes such as a rectangle or a square, a circle, an ellipse, and shapes that are combinations of these.

The planar shapes of the first through hole 21aa, the first through hole 21ab, the second through hole 21ba, and the second through hole 21bb may be the same as each other, may be different from each other, or may be partially different.

When the first through hole 21aa and the second through hole 21ba overlap and communicate with each other, it is preferable that the planar shapes of the first through hole 21aa and the second through hole 21ba are the same as each other.

When the first through hole 21ab and the second through hole 21bb overlap and communicate with each other, it is preferable that the planar shapes of the first through hole 21ab and the second through hole 21bb are the same as each other.

In the first aspect of the capacitor of the present invention, it is sufficient that the characteristic that "the through hole extends in an angle of less than 45° with respect to the opening surface of the opening, and the entire through hole is embedded in the filling resin" is satisfied for at least one through hole. For example, in the capacitor 1, it is sufficient that the above characteristic is satisfied for at least one through hole selected from the group consisting of the first through hole 21aa, the first through hole 21ab, the second through hole 21ba, and the second through hole 21bb.

The portion of the first busbar 20a that protrudes outward from the opening 31 of the exterior case 30 may or may not have a through hole as shown in FIG. 1, etc.

The portion of the second busbar 20b that protrudes outward from the opening 31 of the exterior case 30 may or may not have a through hole as shown in FIG. 1, etc.

When a through hole is provided in at least one of the first bus bar 20a and the second bus bar 20b in a portion that protrudes from the opening 31 of the exterior case 30 toward the outside, it is preferable that the through hole is provided outside the filling resin 40 (not embedded in the filling resin 40).

The first aspect of the capacitor of the present invention is not limited to the above embodiment, and various applications and modifications can be made within the scope of the present invention with respect to the capacitor configuration, manufacturing conditions, etc.

For example, in the first embodiment of the capacitor of the present invention, the number of capacitor elements housed inside one exterior case is not particularly limited. In other words, in the first embodiment of the capacitor of the present invention, one capacitor element may be housed inside one exterior case, or multiple capacitor elements (two capacitor elements in the example shown in FIG. 1, etc.) may be housed inside the exterior case.

In addition, in the first embodiment of the capacitor of the present invention, the number of through holes provided in the portion located between the capacitor element and the opening in one bus bar is not particularly limited. In other words, in the first embodiment of the capacitor of the present invention, the portion located between the capacitor element and the opening in one bus bar may have one through hole or multiple through holes (two in the example shown in FIG. 1, etc.).

In a second aspect, the capacitor of the present invention comprises a capacitor element having an element body and an external electrode provided on a surface of the element body, a bus bar electrically connected to the external electrode, a bottomed cylindrical exterior case with an opening and in which the capacitor element is housed so that the bus bar protrudes from the opening to the outside, and a filling resin filled inside the exterior case so as to embed the capacitor element, wherein a through hole and a protruding portion protruding from the periphery of the through hole are provided in a portion of the bus bar located between the capacitor element and the opening, the protruding direction in which at least the tip side portion of the protruding portion extends forms an angle of less than 45° with respect to the opening plane of the opening, and at least a portion of the through hole and the entire protruding portion are embedded in the filling resin.

The second aspect of the capacitor of the present invention is similar to the first aspect of the capacitor of the present invention, except that "in the busbar, a through hole and a protruding portion protruding from the periphery of the through hole are provided in a portion located between the capacitor element and the opening, the protruding direction in which at least the tip side portion of the protruding portion extends forms an angle of less than 45° with respect to the opening plane of the opening, and at least a portion of the through hole and the entire protruding portion are embedded in the filling resin."

[Embodiment 2]
Hereinafter, an example of the second aspect of the capacitor of the present invention will be described as a capacitor of embodiment 2 of the present invention.

In the capacitor of embodiment 2 of the present invention, the entire through hole and the entire protrusion are embedded in the filling resin.

Figure 8 is a schematic diagram showing an oblique view of an example of a capacitor according to embodiment 2 of the present invention. Figure 9 is a schematic diagram showing an example of the capacitor shown in Figure 8 (excluding the filled resin) in an exploded state.

The capacitor 2 shown in Figures 8 and 9 has a capacitor element 10, a first bus bar 20a, a second bus bar 20b, an outer case 30, and a filling resin 40.

The characteristics of each component of the capacitor 2, the capacitor element 10, the first bus bar 20a, the second bus bar 20b, the exterior case 30, and the filling resin 40, are the same as those of each component of the capacitor 1 described above, except for the following points. In the example shown in FIG. 9, in the region where the first bus bar 20a and the second bus bar 20b overlap, a gap of a predetermined distance is provided between the first bus bar 20a and the second bus bar 20b, specifically, between the second main surface 20ab of the first bus bar 20a and the second main surface 20bb of the second bus bar 20b.

Figure 10 is a schematic diagram showing an oblique cross-section of the capacitor shown in Figure 8. Figure 11 is a schematic diagram showing the capacitor shown in Figure 10 with the filling resin removed. Figure 12 is a schematic diagram showing the cross-section of the capacitor shown in Figure 11 in a plan view.

As shown in Figures 10, 11, and 12, the first busbar 20a has a first through hole 21aa and a first protrusion 25aa protruding from the periphery of the first through hole 21aa in a portion located between the capacitor element 10 and the opening 31.

12, the protruding direction DPaa in which at least the tip side portion of the first protruding portion 25aa extends (hereinafter also referred to as the protruding direction DPaa of the first protruding portion 25aa) forms an angle of less than 45° with respect to the opening surface 31s of the opening 31. Specifically, the protruding direction DPaa of the first protruding portion 25aa forms an angle of 0° or more and less than 45° with respect to the opening surface 31s of the opening 31.

The protruding direction DPaa of the first protruding portion 25aa is determined as a direction in which the tip side portion of the first protruding portion 25aa substantially extends in a path in which the first protruding portion 25aa extends from the base (the peripheral side of the first through hole 21aa) to the tip (the side opposite the peripheral side of the first through hole 21aa). For example, when the first protruding portion 25aa extends from the base to the tip in a planar shape (straight line when viewed in cross section), the protruding direction DPaa of the first protruding portion 25aa is determined as a direction in which the entire first protruding portion 25aa including the tip side portion of the first protruding portion 25aa extends. Also, when the first protruding portion 25aa extends from the base to the tip in a manner other than a planar shape (a manner other than a straight line when viewed in cross section), the protruding direction DPaa of the first protruding portion 25aa is determined as a direction in which the tip side portion of the first protruding portion 25aa extends. The protrusion directions of other protrusions are determined in a similar manner.

As shown in Figures 10 and 11, the entire first through hole 21aa and the entire first protrusion 25aa are embedded in the filling resin 40.

In the capacitor 2, the first through hole 21aa is entirely embedded in the filled resin 40, and the first bus bar 20a is fixed by the filled resin 40 that has entered the first through hole 21aa. In the capacitor 2, the first protrusion 25aa is entirely embedded in the filled resin 40, and the first bus bar 20a is fixed by the filled resin 40 that has bitten into the first protrusion 25aa. Furthermore, in the capacitor 2, the protruding direction DPaa of the first protruding portion 25aa forms an angle of less than 45° with respect to the opening surface 31s of the opening 31, so that the movement of the first busbar 20a, which is caused by the expansion or contraction of the capacitor element 10 when the temperature of the usage environment changes, in the shear direction relative to the filled resin 40 (particularly, the side of the opening surface 31s of the opening 31 or the side opposite to the opening surface 31s relative to the filled resin 40), is suppressed by the filled resin 40 that has entered the first through hole 21aa and further by the filled resin 40 that has bitten into the first protruding portion 25aa. As a result, in the capacitor 2, the occurrence of peeling between the first busbar 20a and the filled resin 40 caused by shear stress at the interface between the first busbar 20a and the filled resin 40, and the occurrence of cracks in the filled resin 40 caused by the stress (pressure) from the first busbar 20a moving in the shear direction are suppressed.

For the above reasons, like Capacitor 1, Capacitor 2 has the advantageous effect of being able to suppress the occurrence of peeling between the busbar and the filled resin, and the occurrence of cracks in the filled resin, even when the temperature of the usage environment changes, compared to, for example, the capacitor described in Patent Document 1 and the electrical component described in Patent Document 2.

From the viewpoint of enhancing the above-mentioned effects of the capacitor 2, it is preferable that the protruding direction DPaa of the first protrusion 25aa is parallel to the opening surface 31s of the opening 31, as shown in FIG. 12.

In the example shown in FIG. 12, the protruding direction DPaa of the first protruding portion 25aa is parallel to the third direction D3. Also, in the example shown in FIG. 12, the opening surface 31s of the opening 31 is parallel to the third direction D3. Therefore, in the example shown in FIG. 12, the protruding direction DPaa of the first protruding portion 25aa is parallel to the opening surface 31s of the opening 31. In other words, in the example shown in FIG. 12, the protruding direction DPaa of the first protruding portion 25aa forms an angle of 0° with respect to the opening surface 31s of the opening 31.

The protruding direction DPaa of the first protrusion 25aa may form an angle greater than 0° and less than 45° with respect to the opening surface 31s of the opening 31.

From the viewpoint of enhancing the above-mentioned effects of the capacitor 2, as shown in FIG. 12, it is preferable that the penetration direction DHaa of the first through hole 21aa forms an angle of less than 45° with respect to the opening surface 31s of the opening 31. Specifically, it is preferable that the penetration direction DHaa of the first through hole 21aa forms an angle of 0° or more and less than 45° with respect to the opening surface 31s of the opening 31.

From the viewpoint of enhancing the above-mentioned effects of the capacitor 2, it is more preferable that the penetration direction DHaa of the first through hole 21aa is parallel to the opening surface 31s of the opening 31, as shown in FIG. 12.

In the example shown in FIG. 12, the through-hole direction DHaa of the first through-hole 21aa is parallel to the third direction D3. Also, in the example shown in FIG. 12, the opening surface 31s of the opening 31 is parallel to the third direction D3. Therefore, in the example shown in FIG. 12, the through-hole direction DHaa of the first through-hole 21aa is parallel to the opening surface 31s of the opening 31. In other words, in the example shown in FIG. 12, the through-hole direction DHaa of the first through-hole 21aa forms an angle of 0° with respect to the opening surface 31s of the opening 31.

The penetration direction DHaa of the first through hole 21aa may form an angle greater than 0° and less than 45° with respect to the opening surface 31s of the opening 31.

The penetration direction DHaa of the first through hole 21aa may be parallel to the thickness direction of the first bus bar 20a (the third direction D3 in FIG. 12), or may not be parallel to the thickness direction of the first bus bar 20a (it may be inclined with respect to the thickness direction of the first bus bar 20a).

When the penetration direction DHaa of the first through hole 21aa is parallel to the thickness direction of the first bus bar 20a, it is perpendicular to the first main surface 20aa or the second main surface 20ab of the first bus bar 20a.

If the penetration direction DHaa of the first through hole 21aa is not parallel to the thickness direction of the first bus bar 20a (if it is inclined relative to the thickness direction of the first bus bar 20a), it is not perpendicular to the first main surface 20aa or the second main surface 20ab of the first bus bar 20a (if it is inclined relative to the first main surface 20aa or the second main surface 20ab of the first bus bar 20a).

As shown in FIG. 12, it is preferable that the surface of the first busbar 20a on which the first through hole 21aa (as well as the first through hole 21ab described below) is provided is perpendicular to the opening surface 31s of the opening 31.

In the example shown in FIG. 12, the first main surface 20aa and the second main surface 20ab of the first busbar 20a in which the first through hole 21aa is provided are perpendicular to the opening surface 31s of the opening 31.

The first main surface 20aa and the second main surface 20ab of the first busbar 20a in which the first through hole 21aa is provided do not have to be perpendicular to the opening surface 31s of the opening 31.

As shown in Figures 10, 11, and 12, the first busbar 20a further includes a first through hole 21ab and a first protrusion 25ab protruding from the periphery of the first through hole 21ab in a portion located between the capacitor element 10 and the opening 31.

As shown in FIG. 12, the protruding direction DPab in which at least the tip side portion of the first protruding portion 25ab extends (hereinafter also referred to as the protruding direction DPab of the first protruding portion 25ab) forms an angle of less than 45° with respect to the opening surface 31s of the opening 31.

As shown in Figures 10 and 11, the entire first through hole 21ab and the entire first protrusion 25ab are embedded in the filling resin 40.

In the capacitor 2, the protruding direction DPab of the first protruding portion 25ab forms an angle of less than 45° with respect to the opening surface 31s of the opening 31, and the entire first through hole 21ab and the entire first protruding portion 25ab are embedded in the filled resin 40. As a result, in the same manner as the mechanism described above, even if the temperature of the usage environment changes, peeling between the first bus bar 20a and the filled resin 40 and cracks in the filled resin 40 are suppressed.

The characteristics of the first through hole 21ab (e.g., the penetration direction DHab of the first through hole 21ab) are similar to the characteristics of the first through hole 21aa, including the points described above.

The characteristics of the first protrusion 25ab (e.g., the protrusion direction DPab of the first protrusion 25ab) are similar to the characteristics of the first protrusion 25aa, including the points described above.

As shown in Figures 10, 11, and 12, the second busbar 20b has a second through hole 21ba and a second protruding portion 25ba protruding from the periphery of the second through hole 21ba in a portion located between the capacitor element 10 and the opening 31.

As shown in FIG. 12, the protruding direction DPba in which at least the tip side portion of the second protruding portion 25ba extends (hereinafter also referred to as the protruding direction DPba of the second protruding portion 25ba) forms an angle of less than 45° with respect to the opening surface 31s of the opening 31.

As shown in Figures 10 and 11, the entire second through hole 21ba and the entire second protrusion 25ba are embedded in the filling resin 40.

In the capacitor 2, the protruding direction DPba of the second protruding portion 25ba forms an angle of less than 45° with respect to the opening surface 31s of the opening 31, and the entire second through hole 21ba and the entire second protruding portion 25ba are embedded in the filled resin 40. As a result, in the same manner as the mechanism described above, even if the temperature of the usage environment changes, peeling between the second bus bar 20b and the filled resin 40 and cracks in the filled resin 40 are suppressed.

The characteristics of the second through hole 21ba (e.g., the penetration direction DHba of the second through hole 21ba) are similar to the characteristics of the first through hole 21aa, including the points described above.

The characteristics of the second protrusion 25ba (e.g., the protrusion direction DPba of the second protrusion 25ba) are similar to the characteristics of the first protrusion 25aa, including the points described above.

As shown in FIG. 12, it is preferable that the surface of the second busbar 20b on which the second through hole 21ba (as well as the second through hole 21bb described later) is provided is perpendicular to the opening surface 31s of the opening 31.

In the example shown in FIG. 12, the first main surface 20ba and the second main surface 20bb of the second busbar 20b in which the second through hole 21ba is provided are perpendicular to the opening surface 31s of the opening 31.

The first main surface 20ba and the second main surface 20bb of the second busbar 20b in which the second through hole 21ba is provided do not have to be perpendicular to the opening surface 31s of the opening 31.

As shown in Figures 10, 11, and 12, the second busbar 20b further includes a second through hole 21bb and a second protrusion 25bb protruding from the periphery of the second through hole 21bb in a portion located between the capacitor element 10 and the opening 31.

As shown in FIG. 12, the protruding direction DPbb in which at least the tip side portion of the second protruding portion 25bb extends (hereinafter also referred to as the protruding direction DPbb of the second protruding portion 25bb) forms an angle of less than 45° with respect to the opening surface 31s of the opening 31.

As shown in Figures 10 and 11, the entire second through hole 21bb and the entire second protrusion 25bb are embedded in the filling resin 40.

In the capacitor 2, the protruding direction DPbb of the second protruding portion 25bb forms an angle of less than 45° with respect to the opening surface 31s of the opening 31, and the entire second through hole 21bb and the entire second protruding portion 25bb are embedded in the filled resin 40. As a result, in the same manner as the mechanism described above, even if the temperature of the usage environment changes, peeling between the second bus bar 20b and the filled resin 40 and cracks in the filled resin 40 are suppressed.

The characteristics of the second through hole 21bb (e.g., the penetration direction DHbb of the second through hole 21bb) are similar to the characteristics of the first through hole 21aa, including the points described above.

The characteristics of the second protrusion 25bb (e.g., the protrusion direction DPbb of the second protrusion 25bb) are similar to the characteristics of the first protrusion 25aa, including the points described above.

9, 11, and 12, in the region where the first busbar 20a and the second busbar 20b overlap, it is preferable that at least a part of the first through hole 21aa and at least a part of the second through hole 21ba overlap and communicate with each other. In this case, in the capacitor 2, the first busbar 20a and the second busbar 20b are more firmly fixed by the filled resin 40 that has entered the first through hole 21aa and the second through hole 21ba, so that even if the temperature of the usage environment changes, the occurrence of peeling between the first busbar 20a and the filled resin 40, the occurrence of peeling between the second busbar 20b and the filled resin 40, and the occurrence of cracks in the filled resin 40 are more suppressed.

In the examples shown in Figures 9, 11, and 12, in the region where the first bus bar 20a and the second bus bar 20b overlap, the entire first through hole 21aa and the entire second through hole 21ba overlap and communicate with each other, but the entire first through hole 21aa and a part of the second through hole 21ba may overlap and communicate with each other, a part of the first through hole 21aa and the entire second through hole 21ba may overlap and communicate with each other, or a part of the first through hole 21aa and a part of the second through hole 21ba may overlap and communicate with each other.

9, 11, and 12, in the region where the first busbar 20a and the second busbar 20b overlap, it is preferable that at least a part of the first through hole 21ab and at least a part of the second through hole 21bb overlap and communicate with each other. In this case, in the capacitor 2, the first busbar 20a and the second busbar 20b are more firmly fixed by the filled resin 40 that has entered the first through hole 21ab and the second through hole 21bb, so that even if the temperature of the usage environment changes, the occurrence of peeling between the first busbar 20a and the filled resin 40, the occurrence of peeling between the second busbar 20b and the filled resin 40, and the occurrence of cracks in the filled resin 40 are more suppressed.

In the examples shown in Figures 9, 11, and 12, in the region where the first bus bar 20a and the second bus bar 20b overlap, the entire first through hole 21ab and the entire second through hole 21bb overlap and communicate with each other, but the entire first through hole 21ab and a part of the second through hole 21bb may overlap and communicate with each other, or a part of the first through hole 21ab and the entire second through hole 21bb may overlap and communicate with each other, or a part of the first through hole 21ab and a part of the second through hole 21bb may overlap and communicate with each other.

As shown in Figures 9, 11, and 12, it is preferable that the first protrusion 25aa and the second protrusion 25ba extend in opposite directions toward their respective tips. In this case, in the capacitor 2, the first bus bar 20a and the second bus bar 20b are more firmly fixed by the filled resin 40 that is embedded in each of the first protrusion 25aa and the second protrusion 25ba, so that even if the temperature of the usage environment changes, the occurrence of peeling between the first bus bar 20a and the filled resin 40, the occurrence of peeling between the second bus bar 20b and the filled resin 40, and the occurrence of cracks in the filled resin 40 are more suppressed.

As shown in Figures 9, 11, and 12, it is preferable that the first protrusion 25ab and the second protrusion 25bb extend in opposite directions toward their respective tips. In this case, in the capacitor 2, the first busbar 20a and the second busbar 20b are more firmly fixed by the filled resin 40 that is embedded in each of the first protrusion 25ab and the second protrusion 25bb, so that even if the temperature of the usage environment changes, peeling between the first busbar 20a and the filled resin 40, peeling between the second busbar 20b and the filled resin 40, and cracks in the filled resin 40 are more suppressed.

At least one of the first protrusion 25aa and the first protrusion 25ab is preferably integrated with the first busbar 20a. In other words, at least one of the first protrusion 25aa and the first protrusion 25ab is preferably part of the first busbar 20a.

In this specification, two elements being integrated means that there is no interface between the elements, for example, the boundary between the elements cannot be distinguished.

At least one of the first protrusion 25aa and the first protrusion 25ab does not have to be integrated with the first busbar 20a. For example, at least one of the first protrusion 25aa and the first protrusion 25ab may be joined or adhered to the first busbar 20a as a separate member independent of the first busbar 20a.

At least one of the second protrusions 25ba and 25bb is preferably integrated with the second busbar 20b. In other words, at least one of the second protrusions 25ba and 25bb is preferably part of the second busbar 20b.

At least one of the second protrusions 25ba and 25bb does not have to be integrated with the second busbar 20b. For example, at least one of the second protrusions 25ba and 25bb may be joined or adhered to the second busbar 20b as a separate member independent of the second busbar 20b.

The planar shapes of the first protrusion 25aa, the first protrusion 25ab, the second protrusion 25ba, and the second protrusion 25bb (in FIG. 9, the planar shapes when viewed from the first direction D1) are not particularly limited, and examples include rectangular shapes such as a rectangle or a square, a circle, an ellipse, and shapes that are combinations of these.

The planar shapes of the first protrusion 25aa, the first protrusion 25ab, the second protrusion 25ba, and the second protrusion 25bb may be the same as each other, may be different from each other, or may be partially different.

[Embodiment 3]
Hereinafter, another example of the capacitor according to the second aspect of the present invention will be described as a capacitor according to a third embodiment of the present invention.

In the capacitor of embodiment 3 of the present invention, unlike the capacitor of embodiment 2 of the present invention, a part of the through hole and the entire protrusion are embedded in the filling resin.

The capacitor of embodiment 3 of the present invention is similar to the capacitor of embodiment 2 of the present invention except for the above points.

Figure 13 is a schematic diagram showing an oblique view of an example of a capacitor according to embodiment 3 of the present invention. Figure 14 is a schematic diagram showing an example of the capacitor shown in Figure 13 (excluding the filled resin) in an exploded state.

The capacitor 3 shown in Figures 13 and 14 has a capacitor element 10, a first bus bar 20a, a second bus bar 20b, an outer case 30, and a filling resin 40.

The characteristics of each component of the capacitor 3, the capacitor element 10, the first bus bar 20a, the second bus bar 20b, the exterior case 30, and the filling resin 40, are the same as those of each component described above in the capacitor 1, except for the following points. Note that in the example shown in Figures 13 and 14, in the region where the first bus bar 20a and the second bus bar 20b overlap, a gap of a predetermined distance is provided between the first bus bar 20a and the second bus bar 20b, specifically, between the second main surface 20ab of the first bus bar 20a and the second main surface 20bb of the second bus bar 20b.

Figure 15 is a schematic diagram showing an oblique cross-section of the capacitor shown in Figure 13. Figure 16 is a schematic diagram showing the capacitor shown in Figure 15 with the filling resin removed. Figure 17 is a schematic diagram showing the cross-section of the capacitor shown in Figure 16 in a plan view.

As shown in Figures 15, 16, and 17, the first bus bar 20a has a first through hole 21aa and a first protrusion 25aa protruding from the periphery of the first through hole 21aa in a portion located between the capacitor element 10 and the opening 31.

As shown in FIG. 17, the protruding direction DPaa of the first protruding portion 25aa forms an angle of less than 45° with respect to the opening surface 31s of the opening 31. Specifically, the protruding direction DPaa of the first protruding portion 25aa forms an angle of 0° or more and less than 45° with respect to the opening surface 31s of the opening 31.

As shown in Figures 15 and 16, a portion of the first through hole 21aa and the entire first protrusion 25aa are embedded in the filling resin 40.

In the capacitor 3, a portion of the first through hole 21aa is embedded in the filled resin 40, so that the length of the interface between the first bus bar 20a and the filled resin 40 is smaller than in the capacitor 2, and the stress caused by the difference in the thermal expansion coefficients of the first bus bar 20a and the filled resin 40 is reduced. As a result, in the capacitor 3, the occurrence of peeling between the first bus bar 20a and the filled resin 40 and the occurrence of cracks in the filled resin 40 are suppressed compared to the capacitor 2.

In the electrical component described in Patent Document 2, as shown in FIG. 4 of Patent Document 2, only a portion of the through hole 13 is embedded in the resin 32, but there is no protruding portion that protrudes from the periphery of the through hole 13 and is entirely embedded in the resin 32. This means that the movement of the connection terminal 11, which shifts in the shear direction relative to the resin 32 (particularly, toward the opening surface of the opening of the case 31 or the opposite side to the opening surface relative to the resin 32) caused by the expansion or contraction of the electrical element 21 when the temperature of the usage environment changes, is difficult to suppress.

For the above reasons, like Capacitor 1 and Capacitor 2, Capacitor 3 has the advantageous effect of being able to suppress the occurrence of peeling between the busbar and the filled resin, and the occurrence of cracks in the filled resin, even when the temperature of the usage environment changes, compared to, for example, the capacitor described in Patent Document 1 and the electrical component described in Patent Document 2.

From the viewpoint of enhancing the above-mentioned effect of the capacitor 3, it is preferable that the protruding direction DPaa of the first protrusion 25aa is parallel to the opening surface 31s of the opening 31, as shown in FIG. 17.

In the example shown in FIG. 17, the protruding direction DPaa of the first protruding portion 25aa is parallel to the third direction D3. Also, in the example shown in FIG. 17, the opening surface 31s of the opening 31 is parallel to the third direction D3. Therefore, in the example shown in FIG. 17, the protruding direction DPaa of the first protruding portion 25aa is parallel to the opening surface 31s of the opening 31. In other words, in the example shown in FIG. 17, the protruding direction DPaa of the first protruding portion 25aa forms an angle of 0° with respect to the opening surface 31s of the opening 31.

The protruding direction DPaa of the first protrusion 25aa may form an angle greater than 0° and less than 45° with respect to the opening surface 31s of the opening 31.

From the viewpoint of enhancing the above-mentioned effect of the capacitor 3, as shown in FIG. 17, it is preferable that the penetration direction DHaa of the first through hole 21aa forms an angle of less than 45° with respect to the opening surface 31s of the opening 31. Specifically, it is preferable that the penetration direction DHaa of the first through hole 21aa forms an angle of 0° or more and less than 45° with respect to the opening surface 31s of the opening 31.

From the viewpoint of enhancing the above-mentioned effects of the capacitor 3, it is more preferable that the penetration direction DHaa of the first through hole 21aa is parallel to the opening surface 31s of the opening 31, as shown in FIG. 17.

17, the through-hole direction DHaa of the first through-hole 21aa is parallel to the third direction D3. Also, in the example shown in FIG. 17, the opening surface 31s of the opening 31 is parallel to the third direction D3. Therefore, in the example shown in FIG. 17, the through-hole direction DHaa of the first through-hole 21aa is parallel to the opening surface 31s of the opening 31. In other words, in the example shown in FIG. 17, the through-hole direction DHaa of the first through-hole 21aa forms an angle of 0° with respect to the opening surface 31s of the opening 31.

The penetration direction DHaa of the first through hole 21aa may form an angle greater than 0° and less than 45° with respect to the opening surface 31s of the opening 31.

The penetration direction DHaa of the first through hole 21aa may be parallel to the thickness direction of the first bus bar 20a (the third direction D3 in FIG. 17), or may not be parallel to the thickness direction of the first bus bar 20a (it may be inclined with respect to the thickness direction of the first bus bar 20a).

When the penetration direction DHaa of the first through hole 21aa is parallel to the thickness direction of the first bus bar 20a, it is perpendicular to the first main surface 20aa or the second main surface 20ab of the first bus bar 20a.

If the penetration direction DHaa of the first through hole 21aa is not parallel to the thickness direction of the first bus bar 20a (if it is inclined relative to the thickness direction of the first bus bar 20a), it is not perpendicular to the first main surface 20aa or the second main surface 20ab of the first bus bar 20a (if it is inclined relative to the first main surface 20aa or the second main surface 20ab of the first bus bar 20a).

As shown in FIG. 17, it is preferable that the surface of the first busbar 20a on which the first through hole 21aa (as well as the first through hole 21ab described below) is provided is perpendicular to the opening surface 31s of the opening 31.

In the example shown in FIG. 17, the first main surface 20aa and the second main surface 20ab of the first busbar 20a in which the first through hole 21aa is provided are perpendicular to the opening surface 31s of the opening 31.

The first main surface 20aa and the second main surface 20ab of the first busbar 20a in which the first through hole 21aa is provided do not have to be perpendicular to the opening surface 31s of the opening 31.

As shown in Figures 15, 16, and 17, the first busbar 20a further includes a first through hole 21ab and a first protrusion 25ab protruding from the periphery of the first through hole 21ab in a portion located between the capacitor element 10 and the opening 31.

As shown in FIG. 17, the protruding direction DPab of the first protrusion 25ab forms an angle of less than 45° with respect to the opening surface 31s of the opening 31.

As shown in Figures 15 and 16, a portion of the first through hole 21ab and the entire first protrusion 25ab are embedded in the filling resin 40.

In the capacitor 3, the protruding direction DPab of the first protruding portion 25ab forms an angle of less than 45° with respect to the opening surface 31s of the opening 31, and a part of the first through hole 21ab and the entire first protruding portion 25ab are embedded in the filled resin 40. As a result, in the same manner as the mechanism described above, even if the temperature of the usage environment changes, peeling between the first bus bar 20a and the filled resin 40 and cracks in the filled resin 40 are suppressed.

The characteristics of the first through hole 21ab (e.g., the penetration direction DHab of the first through hole 21ab) are similar to the characteristics of the first through hole 21aa, including the points described above.

The characteristics of the first protrusion 25ab (e.g., the protrusion direction DPab of the first protrusion 25ab) are similar to the characteristics of the first protrusion 25aa, including the points described above.

As shown in Figures 15, 16, and 17, the second busbar 20b has a second through hole 21ba and a second protruding portion 25ba protruding from the periphery of the second through hole 21ba in a portion located between the capacitor element 10 and the opening 31.

As shown in FIG. 17, the protruding direction DPba of the second protrusion 25ba forms an angle of less than 45° with respect to the opening surface 31s of the opening 31.

As shown in Figures 15 and 16, a portion of the second through hole 21ba and the entire second protrusion 25ba are embedded in the filling resin 40.

In the capacitor 3, the protruding direction DPba of the second protruding portion 25ba forms an angle of less than 45° with respect to the opening surface 31s of the opening 31, and a part of the second through hole 21ba and the entire second protruding portion 25ba are embedded in the filled resin 40. As a result, in the same manner as the mechanism described above, even if the temperature of the usage environment changes, peeling between the second bus bar 20b and the filled resin 40 and cracks in the filled resin 40 are suppressed.

The characteristics of the second through hole 21ba (e.g., the penetration direction DHba of the second through hole 21ba) are similar to the characteristics of the first through hole 21aa, including the points described above.

The characteristics of the second protrusion 25ba (e.g., the protrusion direction DPba of the second protrusion 25ba) are similar to the characteristics of the first protrusion 25aa, including the points described above.

As shown in FIG. 17, it is preferable that the surface of the second busbar 20b on which the second through hole 21ba (as well as the second through hole 21bb described later) is provided is perpendicular to the opening surface 31s of the opening 31.

In the example shown in FIG. 17, the first main surface 20ba and the second main surface 20bb of the second busbar 20b in which the second through hole 21ba is provided are perpendicular to the opening surface 31s of the opening 31.

The first main surface 20ba and the second main surface 20bb of the second busbar 20b in which the second through hole 21ba is provided do not have to be perpendicular to the opening surface 31s of the opening 31.

As shown in Figures 15, 16, and 17, the second busbar 20b further includes a second through hole 21bb and a second protrusion 25bb protruding from the periphery of the second through hole 21bb in a portion located between the capacitor element 10 and the opening 31.

As shown in FIG. 17, the protruding direction DPbb of the second protrusion 25bb forms an angle of less than 45° with respect to the opening surface 31s of the opening 31.

As shown in Figures 15 and 16, a portion of the second through hole 21bb and the entire second protrusion 25bb are embedded in the filling resin 40.

In the capacitor 3, the protruding direction DPbb of the second protruding portion 25bb forms an angle of less than 45° with respect to the opening surface 31s of the opening 31, and a part of the second through hole 21bb and the entire second protruding portion 25bb are embedded in the filled resin 40. As a result, in the same manner as the mechanism described above, even if the temperature of the usage environment changes, peeling between the second bus bar 20b and the filled resin 40 and cracks in the filled resin 40 are suppressed.

The characteristics of the second through hole 21bb (e.g., the penetration direction DHbb of the second through hole 21bb) are similar to the characteristics of the first through hole 21aa, including the points described above.

The characteristics of the second protrusion 25bb (e.g., the protrusion direction DPbb of the second protrusion 25bb) are similar to the characteristics of the first protrusion 25aa, including the points described above.

13, 14, 15, 16, and 17, in the region where the first busbar 20a and the second busbar 20b overlap, it is preferable that at least a part of the first through hole 21aa and at least a part of the second through hole 21ba overlap and communicate with each other. In this case, in the capacitor 3, the first busbar 20a and the second busbar 20b are more firmly fixed by the filled resin 40 that has entered the first through hole 21aa and the second through hole 21ba, so that even if the temperature of the usage environment changes, the occurrence of peeling between the first busbar 20a and the filled resin 40, the occurrence of peeling between the second busbar 20b and the filled resin 40, and the occurrence of cracks in the filled resin 40 are more suppressed.

In the examples shown in Figures 13, 14, 15, 16, and 17, in the region where the first bus bar 20a and the second bus bar 20b overlap, the entire first through hole 21aa and the entire second through hole 21ba overlap and communicate with each other, but the entire first through hole 21aa and a part of the second through hole 21ba may overlap and communicate with each other, a part of the first through hole 21aa and the entire second through hole 21ba may overlap and communicate with each other, or a part of the first through hole 21aa and a part of the second through hole 21ba may overlap and communicate with each other.

13, 14, 15, 16, and 17, in the region where the first busbar 20a and the second busbar 20b overlap, it is preferable that at least a part of the first through hole 21ab and at least a part of the second through hole 21bb overlap and communicate with each other. In this case, in the capacitor 3, the first busbar 20a and the second busbar 20b are more firmly fixed by the filled resin 40 that has entered the first through hole 21ab and the second through hole 21bb, so that even if the temperature of the usage environment changes, the occurrence of peeling between the first busbar 20a and the filled resin 40, the occurrence of peeling between the second busbar 20b and the filled resin 40, and the occurrence of cracks in the filled resin 40 are more suppressed.

In the examples shown in Figures 13, 14, 15, 16, and 17, in the region where the first bus bar 20a and the second bus bar 20b overlap, the entire first through hole 21ab and the entire second through hole 21bb overlap and communicate with each other, but the entire first through hole 21ab and a part of the second through hole 21bb may overlap and communicate with each other, or a part of the first through hole 21ab and the entire second through hole 21bb may overlap and communicate with each other, or a part of the first through hole 21ab and a part of the second through hole 21bb may overlap and communicate with each other.

In the second aspect of the capacitor of the present invention, the feature that "the protruding direction in which at least the tip side portion of the protruding portion extends forms an angle of less than 45° with respect to the opening surface of the opening, and at least a part of the through hole and the entire protruding portion are embedded in the filling resin" may be satisfied for at least one combination of the through hole and the protruding portion. For example, in the capacitors 2 and 3, the feature may be satisfied for at least one combination of the through hole and the protruding portion selected from the group consisting of the combination of the first through hole 21aa and the first protruding portion 25aa, the combination of the first through hole 21ab and the first protruding portion 25ab, the combination of the second through hole 21ba and the second protruding portion 25ba, and the combination of the second through hole 21bb and the second protruding portion 25bb.

The second aspect of the capacitor of the present invention is not limited to the above embodiment, and various applications and modifications can be made within the scope of the present invention with respect to the capacitor configuration, manufacturing conditions, etc.

For example, in the second embodiment of the capacitor of the present invention, the number of capacitor elements housed inside one exterior case is not particularly limited. In other words, in the second embodiment of the capacitor of the present invention, one capacitor element may be housed inside one exterior case, or multiple capacitor elements (two capacitor elements in the examples shown in Figures 8, 13, etc.) may be housed inside the exterior case.

In addition, in the second embodiment of the capacitor of the present invention, the number of through holes and protrusions provided in the portion located between the capacitor element and the opening in one bus bar is not particularly limited. In other words, in the second embodiment of the capacitor of the present invention, the portion located between the capacitor element and the opening in one bus bar may have one through hole and one protrusion, or may have multiple through holes and multiple protrusions (two each in the examples shown in Figures 8, 13, etc.).

The capacitor of the present invention is useful, for example, in power conversion devices such as motor drive inverters mounted on electric vehicles.

This specification discloses the following:

＜1＞
a capacitor element having an element body and external electrodes provided on a surface of the element body;
a bus bar electrically connected to the external electrode;
an exterior case having a bottomed cylindrical shape and an opening, the exterior case housing the capacitor element therein such that the bus bar protrudes from the opening to the outside;
a filling resin filled inside the exterior case so as to embed the capacitor element,
a through hole is provided in the bus bar at a portion located between the capacitor element and the opening,
The through hole extends in a direction that forms an angle of less than 45° with respect to an opening surface of the opening,
The capacitor is characterized in that the through hole is entirely filled with the filling resin.

＜2＞
The capacitor according to <1>, wherein the penetration direction is parallel to the opening surface of the opening.

＜3＞
The capacitor according to <1> or <2>, wherein a surface of the bus bar in which the through hole is provided is perpendicular to the opening surface of the opening.

＜4＞
the external electrodes include a first external electrode and a second external electrode,
the bus bars include a first bus bar electrically connected to the first external electrode and a second bus bar electrically connected to the second external electrode,
the through holes include a first through hole provided in the first bus bar and a second through hole provided in the second bus bar,
The capacitor according to any one of <1> to <3>, wherein in a region where the first bus bar and the second bus bar overlap, at least a portion of the first through hole and at least a portion of the second through hole overlap and communicate with each other.

＜5＞
a capacitor element having an element body and external electrodes provided on a surface of the element body;
a bus bar electrically connected to the external electrode;
an exterior case having a bottomed cylindrical shape and an opening, the exterior case housing the capacitor element therein such that the bus bar protrudes from the opening to the outside;
a filling resin filled inside the exterior case so as to embed the capacitor element,
the bus bar is provided with a through hole and a protrusion protruding from a periphery of the through hole in a portion located between the capacitor element and the opening,
A protruding direction in which at least a tip side portion of the protruding portion extends forms an angle of less than 45° with respect to an opening surface of the opening,
A capacitor, characterized in that at least a portion of the through hole and the entire protrusion are embedded in the filling resin.

＜6＞
The capacitor according to <5>, wherein the through hole and the protrusion are entirely embedded in the filling resin.

＜７＞
The capacitor according to <5>, wherein a portion of the through hole and the entire protrusion are embedded in the filling resin.

＜8＞
The capacitor according to any one of <5> to <7>, wherein the protruding direction is parallel to the opening surface of the opening.

＜9＞
The capacitor according to any one of <5> to <8>, wherein a penetration direction in which the through hole extends forms an angle of less than 45° with respect to the opening surface of the opening.

＜10＞
The capacitor according to <9>, wherein the penetration direction is parallel to the opening surface of the opening.

<11>
The capacitor according to any one of <5> to <10>, wherein a surface of the bus bar on which the through hole is provided is perpendicular to the opening surface of the opening.

＜12＞
the external electrodes include a first external electrode and a second external electrode,
the bus bars include a first bus bar electrically connected to the first external electrode and a second bus bar electrically connected to the second external electrode,
the through holes include a first through hole provided in the first bus bar and a second through hole provided in the second bus bar,
The capacitor according to any one of <5> to <11>, wherein in a region where the first bus bar and the second bus bar overlap, at least a portion of the first through hole and at least a portion of the second through hole overlap and communicate with each other.

＜13＞
The capacitor according to any one of <1> to <12>, wherein the capacitor element is a film capacitor.

1, 2, 3 Capacitor 10 Capacitor element 11 Body 11a First end surface 11b of body Second end surface 11c of body Side surface 12a of body First external electrode 12b Second external electrode 13a First metallized film 13b Second metallized film 14a First dielectric film 14aa First main surface 14ab of first dielectric film Second main surface 14b of first dielectric film Second dielectric film 14ba First main surface 14bb of second dielectric film Second main surface 15a of second dielectric film First metal layer 15b Second metal layer 20a First bus bar 20aa First main surface 20ab of first bus bar Second main surface 20b of first bus bar Second bus bar 20ba First main surface 20bb of second bus bar Second main surface 21aa, 21ab of second bus bar First through holes 21aaa, 21aba First end 21aab, 21abb of first through hole Second end 21ba, 21bb of first through hole Second through hole 21baa, 21bba First end 21bab, 21bbb of second through hole Second end 25aa, 25ab First protrusion 25ba, 25bb Second protrusion 30 Exterior case 31 Opening 31s Opening surface 32 of opening Bottom 33 Side wall 40 Filling resin D1 First direction D2 Second direction D3 Third direction DHaa, DHab Penetration direction DHba, DHbb in which first through hole extends Penetration direction DPaa, DPab in which second through hole extends Protruding direction DPba, DPbb in which at least the tip side portion of the first protrusion extends Protruding direction in which at least the tip side portion of the second protrusion extends

Claims (12)

a capacitor element having an element body and external electrodes provided on a surface of the element body;
a bus bar electrically connected to the external electrode;
an exterior case having a bottomed cylindrical shape and an opening, the exterior case housing the capacitor element therein such that the bus bar protrudes from the opening to the outside;
a filling resin filled inside the exterior case so as to embed the capacitor element,
a through hole is provided in the bus bar at a portion located between the capacitor element and the opening,
The through hole has an angle of less than 45° with respect to an opening plane of the opening,
The through hole is entirely embedded in the filling resin ,
the external electrodes include a first external electrode and a second external electrode,
the bus bars include a first bus bar electrically connected to the first external electrode and a second bus bar electrically connected to the second external electrode,
the through holes include a first through hole provided in the first bus bar and a second through hole provided in the second bus bar,
A capacitor characterized in that , in a region where the first bus bar and the second bus bar overlap, at least a portion of the first through hole and at least a portion of the second through hole overlap and communicate with each other . The capacitor of claim 1, wherein the penetration direction is parallel to the opening surface of the opening. The capacitor according to claim 1 or 2, wherein the surface of the busbar on which the through holes are provided is perpendicular to the opening surface of the opening. a capacitor element having an element body and external electrodes provided on a surface of the element body;
a bus bar electrically connected to the external electrode;
an exterior case having a bottomed cylindrical shape and an opening, the exterior case housing the capacitor element therein such that the bus bar protrudes from the opening to the outside;
a filling resin filled inside the exterior case so as to embed the capacitor element,
the bus bar is provided with a through hole and a protrusion protruding from a periphery of the through hole in a portion located between the capacitor element and the opening,
A protruding direction in which at least a tip side portion of the protruding portion extends forms an angle of less than 45° with respect to an opening surface of the opening,
A capacitor, characterized in that at least a portion of the through hole and the entire protrusion are embedded in the filling resin. The capacitor according to claim 4 , wherein the through hole and the protrusion are entirely embedded in the filling resin. The capacitor according to claim 4 , wherein a portion of the through hole and an entirety of the protrusion are embedded in the filling resin. The capacitor according to claim 4 , wherein the protruding direction is parallel to the opening surface of the opening. The capacitor according to claim 4 , wherein a penetration direction in which the through hole extends forms an angle of less than 45° with respect to the opening plane of the opening. The capacitor of claim 8 , wherein the penetration direction is parallel to the opening plane of the opening. The capacitor according to claim 4 , wherein a surface of the bus bar in which the through hole is provided is perpendicular to an opening surface of the opening. the external electrodes include a first external electrode and a second external electrode,
the bus bars include a first bus bar electrically connected to the first external electrode and a second bus bar electrically connected to the second external electrode,
the through holes include a first through hole provided in the first bus bar and a second through hole provided in the second bus bar,
The capacitor according to claim 4 , wherein in a region where the first bus bar and the second bus bar overlap, at least a portion of the first through hole and at least a portion of the second through hole overlap and communicate with each other. The capacitor according to claim 1 or 4 , wherein the capacitor element is a film capacitor.

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