Electrolytic capacitor
By introducing an external pressure deformation suppression plate and a sliding contact and limiting structure between the seal and the electrolytic capacitor, the problem of deformation or movement of the seal under pressure fluctuations is solved, thus achieving stable sealing effect and protection of the lead terminals.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SAN DENSHI INDS
- Filing Date
- 2025-04-29
- Publication Date
- 2026-04-28
AI Technical Summary
The seals of electrolytic capacitors are prone to deformation or movement under pressure fluctuations, which reduces the sealing effect and may have adverse effects on capacitor elements and lead terminals.
An external pressure deformation suppression plate is used in conjunction with the seal. Through sliding contact and limiting structure, the deformation and movement of the seal are restricted to ensure the sealing effect. A gap is left between the lead terminal and the through hole to reduce friction.
It effectively suppresses the reduction of sealing effect of the seal and the adverse effects on capacitor elements and lead terminals, thereby improving the reliability and withstand voltage of electrolytic capacitors.
Smart Images
Figure CN224177228U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to electrolytic capacitors. Background Technology
[0002] An electrolytic capacitor exists, comprising a housing, a capacitor element, a seal, and lead terminals. The housing is a bottomed cylindrical shape, closed at one end and open at the other. The capacitor element is housed within the housing. The seal is plate-shaped and seals the opening of the housing. The capacitor element has an anode foil, an insulating element, and a cathode foil. The anode foil and cathode foil face each other across the insulating element.
[0003] A capacitor element is formed by winding an anode foil, a separator, and a cathode foil. The capacitor element includes at least one of an electrolyte or a solid electrolyte. Lead terminals are respectively connected to one end of the anode foil and the cathode foil. The other end of the lead terminals passes through a seal and extends to an opening in the body housing.
[0004] In such an electrolytic capacitor, a plate-shaped appendage is attached to the end face of the opening side of the main body housing of the seal (Patent Document 1). The entire surface of the seal and the appendage in contact with each other is joined together to form a single unit. The outer diameter of the appendage is configured to be approximately equal to the outer diameter of the seal. Utility Model Content
[0005] The problem to be solved by utility models
[0006] However, depending on the environment in which the electrolytic capacitor is configured, pressure fluctuations inside the casing or from external sources can cause the seal to deform. As mentioned earlier, the appendage engages with the end face of the seal on the opening side. Therefore, the appendage can hinder the deformation of the seal, making it difficult for the seal to keep up with the expansion / contraction of the electrolytic capacitor caused by pressure fluctuations inside the casing. Consequently, the sealing effect of the seal may be reduced.
[0007] As an example of the aforementioned environment, soldering is sometimes performed when mounting electrolytic capacitors onto a circuit board. Specifically, in this case, due to the heat generated by soldering, components inside the casing (such as electrolyte, solid electrolyte components, or moisture contained in the capacitor elements) vaporize, increasing the pressure inside the casing and causing the electrolytic capacitor to sometimes expand. Furthermore, by cooling to room temperature after soldering, the expanded electrolytic capacitor may sometimes shrink back to its original state. When the pressure inside the casing rises, the seals may deform and be pushed outwards from the opening. The effect of heat is particularly pronounced during reflow soldering.
[0008] Furthermore, depending on the environment in which the electrolytic capacitor is configured, the seal may accidentally move from its fixed position. As an example of such an environment, sometimes molding resin is used to mold the area around the electrolytic capacitor. In this case, the seal is pressed towards the capacitor element side (inside the body housing) by the pressure of the injected molding resin. Consequently, the seal may deform due to this pressure, or be pressed into the capacitor element side (inside the body housing), thus moving from its fixed position.
[0009] As mentioned earlier, when the seal moves from its fixed position toward the capacitor element, it presses against the capacitor element, potentially causing adverse effects. Furthermore, the sealing effect of the seal may decrease as it moves from its fixed position. Moreover, the movement of the seal may also adversely affect the lead terminals.
[0010] Therefore, the purpose of this invention is to provide an electrolytic capacitor that can suppress the reduction of the sealing effect of the sealing element and suppress adverse effects on the capacitor element and lead terminals.
[0011] Technical solutions to the problem
[0012] To achieve the above objectives, the electrolytic capacitor of the present invention comprises: a body shell, a capacitor element, a sealing member, an external pressure deformation suppression plate, a first lead terminal, a second lead terminal, and a base plate. The body shell is formed as a bottomed cylindrical shape with one end closed and an opening at the other end. The capacitor element is housed within the body shell. The sealing member forms a first through hole and a second through hole arranged in a first direction, is disposed inside the body shell, and seals the opening. The external pressure deformation suppression plate is disposed in a slidable manner, abutting against the opening-side end face of the sealing member, and forms a third through hole overlapping the first through hole in a second direction orthogonal to the first direction, and a fourth through hole overlapping the second through hole in both the first and second directions. The first lead terminal is connected to the capacitor element within the body shell, and is led out of the body shell through the first and third through holes. The second lead terminal is connected to the capacitor element within the body shell, and is led out of the body shell through the second and fourth through holes. The base plate approaches and faces the end of the main body housing on the open side in a third direction orthogonal to the first and second directions. The first lead terminal has: a first round bar portion located inside the first through hole with an outer diameter larger than the inner diameter of the third through hole; a first welding portion located at the end of the first round bar portion on the open side in the third direction; and a first fixing portion located outside the main body housing and welded to the circuit board. The second lead terminal has: a second round bar portion located inside the second through hole with an outer diameter larger than the inner diameter of the fourth through hole; a second welding portion located at the end of the second round bar portion on the open side in the third direction; and a second fixing portion located outside the main body housing and welded to the circuit board. The main body housing has a main body portion housing an electrolytic capacitor and a narrowing portion extending from the main body portion to the opening with an inner diameter smaller than the inner diameter of the main body portion. A seal is located at a position overlapping the narrowing portion in the third direction. When the seal is pressed towards the capacitor element side in a third direction, the edge of the third through hole abuts against the first welded portion, and the edge of the fourth through hole abuts against the second welded portion, thereby restricting the movement of the seal towards the capacitor element side. Gaps exist between the first lead terminal and the third through hole, and between the second lead terminal and the fourth through hole.
[0013] Utility Model Effect
[0014] According to the first structure of this utility model, the external pressure deformation suppression plate is disposed in a sliding state abutting against the open-side end face of the seal. Therefore, even assuming the seal deforms or moves, the external pressure deformation suppression plate will slide relative to the open-side end face of the seal following the deformation of the seal. Thus, the external pressure deformation suppression plate can hardly prevent the deformation of the seal, and can suppress the reduction of the sealing effect of the seal.
[0015] Furthermore, even when the seal is pressed towards the capacitor element in a third direction, its movement towards the capacitor element is restricted. Therefore, the seal is difficult to move from its fixed position, suppressing any adverse effects on the capacitor element caused by seal movement. Additionally, gaps exist between the first lead terminal and the third through hole, and between the second lead terminal and the fourth through hole. Therefore, even if the seal moves slightly or deforms, the seal (the inner surfaces of the third and fourth through holes) is unlikely to contact the first and second lead terminals. This reduces friction between the first and second lead terminals and the seal. Therefore, any adverse effects on the first and second lead terminals caused by seal movement are suppressed. Attached Figure Description
[0016] Figure 1 This diagram shows the state in which the electrolytic capacitor of this embodiment is mounted on a circuit board.
[0017] Figure 2 It is an enlarged cross-sectional view showing the periphery of the narrowing section.
[0018] Figure 3 This is a three-dimensional diagram showing the structure of a capacitor element.
[0019] Figure 4 This diagram shows the state of the molding around the electrolytic capacitor.
[0020] Figure 5 This is a top view of the seal and the external pressure deformation suppression plate along the Z-direction from the opening side end face.
[0021] Figure 6 It is a 3D view of the seal and the external pressure deformation suppression plate.
[0022] Figure 7 It shows along Figure 6 The cross-sectional view of the electrolytic capacitor obtained by cutting it with straight line L2 is shown. Detailed Implementation
[0023] <Basic Structure>
[0024] The basic structure of the embodiments of this utility model will be described below with reference to the accompanying drawings. Figure 1 This diagram shows the state in which the electrolytic capacitor 1 of this embodiment is mounted on the circuit board 2.
[0025] like Figure 1 As shown, the electrolytic capacitor 1 is mounted on the circuit board 2 via a mounting plate 1a. It should be noted that the direction parallel to the direction in which the electrolytic capacitor 1 is mounted on the circuit board 2 (and...) will be referred to below. Figure 1The direction in which the arrow Z-Z' is parallel is simply referred to as the "Z direction" (= third direction). It should be noted that in each figure, the direction pointed to by the arrow Z-Z' is illustrated as the Z direction.
[0026] The electrolytic capacitor 1 includes a body housing 4, a capacitor element 5, a sealing element 6, a first lead terminal 7a, a second lead terminal 7b, and an external pressure deformation suppression plate 8.
[0027] The body shell 4 is formed, for example, of aluminum. The body shell 4 is a bottomed cylindrical body that is closed at one end in the Z direction and open at the other end. The body shell 4 has a top 4c, a main body 4d, a narrowing portion 4a, and a bending portion 4b. In addition, the body shell 4 forms an opening 3.
[0028] The top 4c closes one end of the main body housing 4 in the Z direction. The opening 3 is located at the other end of the main body housing 4 in the Z direction. The opening 3 is the opening that forms the boundary between the interior and exterior of the main body housing 4. The main body portion 4d extends from the periphery of the top 4c along the Z direction toward the opening 3 (the circuit board 2 side).
[0029] Figure 2 This is an enlarged cross-sectional view showing the periphery of the narrowed portion 4a. For example... Figure 1 , Figure 2 As shown, the narrowing portion 4a is connected to the lower part of the main body portion 4d (the end of the main body portion 4d on the circuit board 2 side) in the Z direction. The narrowing portion 4a is formed to be more towards the inner side of the body housing 4 than the main body portion 4d and the bending portion 4b, and to be narrower in the radial direction of the body housing 4. The preferred position of the narrowing portion 4a in the Z direction is set to be approximately 1 / 2 times its length in the Z direction from the body side end face 6q (described in detail later) to the opening side end face 6r (described in detail later). The narrowing portion 4a is formed in a ring shape, encircling the inner surface of the body housing 4.
[0030] More specifically, the situation is as follows. The inner surface of the narrowing portion 4a protrudes further inward into the body housing 4 than the inner surface of the main body portion 4d in a direction orthogonal to the Z direction (parallel to the circuit board 2). The vertex of the inner surface of the narrowing portion 4a in the direction orthogonal to the Z direction (in other words, the innermost part of the inner surface of the narrowing portion 4a located within the body housing) is designated as vertex P1. The inner diameter d1 of the body housing 4 at vertex P1 is smaller than the inner diameter d2 of the body housing 4 at the main body portion 4d.
[0031] The bent portion 4b is connected to the lower part of the narrowed portion 4a (the end of the narrowed portion 4a on the circuit board 2 side) in the Z direction. As the bent portion 4b approaches the circuit board 2 side from the lower part of the narrowed portion 4a in the Z direction, it bends inward towards the body housing 4 in the Y direction. The front end of the bent portion 4b forms the opening edge of the opening portion 3.
[0032] The lower end portion 4e of the bent portion 4b (the lowermost part of the main body housing 4 located along the Z direction) approaches and faces the surface of the base plate 1a in the Z direction. Here, "approaching and facing" means that the lower end portion 4e and the base plate 1a can either abut against each other or face each other in the Z direction with a small gap between them.
[0033] The capacitor element 5 is housed inside the main body housing 4. The capacitor element 5 is located at a position overlapping the main body portion 4d in the Z direction. The capacitor element 5 holds the electrolyte.
[0034] Figure 3 This is a perspective view showing the structure of capacitor element 5. (As shown...) Figure 3 As shown, capacitor element 5 has an insulating element 10, an anode foil 11, and a cathode foil 12. Capacitor element 5 includes at least one of an electrolyte or a solid electrolyte.
[0035] The spacer 10 overlaps with the anode foil 11. The cathode foil 12 faces the anode foil 11 with a spacer 10 between them. The spacer 10, anode foil 11, and cathode foil 12 are wound together and housed inside the main body 4d (see reference). Figure 1 The width of the spacer 10 in the Z direction is greater than the width of the anode foil 11 and the width of the cathode foil 12.
[0036] The seal 6 is an insulating elastomer. The seal 6 is formed, for example, from butyl rubber, ethylene propylene rubber, etc.
[0037] Seal 6 is a plate-shaped body that appears circular when viewed from above (see below). Figure 5 ).like Figure 1 , Figure 2 As shown, the seal 6 is housed within the main body housing 4. The seal 6 is located in the Z-direction, overlapping with the narrowed portion 4a. In the Z-direction, the seal 6 is positioned between the capacitor element 5 and the opening 3.
[0038] The seal 6 is inserted into the body housing 4. The outer peripheral surface of the seal 6 abuts against the inner peripheral surface of the body housing 4 (more specifically, the inner surface of the narrowed portion 4a). Thus, the seal 6 seals the opening 3. The detailed structure of the seal 6 is as follows.
[0039] The seal 6 has a body side end face 6q, an opening side end face 6r, a first through hole 6a, a second through hole 6b, and retaining portions 6c and 6d.
[0040] The body-side end face 6q is the end face of the seal 6 in the Z direction on the side of the capacitor element 5. The opening-side end face 6r is the end face of the seal 6 in the Z direction on the side of the opening 3.
[0041] The first through hole 6a and the second through hole 6b extend from the body-side end face 6q to the opening-side end face 6r, penetrating the sealing member 6 in the thickness direction (=Z direction). The first through hole 6a and the second through hole 6b are arranged on a straight line L1 parallel to the circuit board 2 (see below). Figure 5 ).
[0042] The direction in which the first through hole 6a and the second through hole 6b are arranged is referred to as the "X direction" (first direction). The direction orthogonal to the X and Z directions is referred to as the "Y direction" (second direction). Furthermore, in each figure, the direction indicated by the arrow X-X' is shown as the X direction. Additionally, the direction indicated by the arrow Y-Y' is shown as the Y direction.
[0043] Retaining portions 6c and 6d are located at both ends of the seal 6 in the X direction. The retaining portions 6c and 6d protrude downwards in the Z direction (opposite to the body side end face 6q) from the edge of the opening-side end face 6r. The retaining portions 6c and 6d face each other in the X direction. The retaining portions 6c and 6d are formed to be interconnected in the Y direction, thereby improving the sliding properties at the contact point between the seal 6 and the body housing 4, which is therefore preferable.
[0044] The outer surface of the retaining parts 6c and 6d in the X direction becomes a cone shape that moves away from the inner peripheral surface of the body housing 4 in the X direction as it approaches the circuit board 2 in the Z direction (in other words, it approaches the center O described later).
[0045] In the Z direction, a gap a1 exists between the inner surfaces of the holding portions 6c and 6d (more specifically, the aforementioned conical portions) and the bent portion 4b. The gap a1 gradually increases from the capacitor element 5 side of the holding portions 6c and 6d towards the opening 3 side. In other words, the gap a1 is smaller on the capacitor element 5 side of the holding portion 6c and larger on the opening 3 side of the holding portion 6c.
[0046] The first lead terminal 7a is inserted into the first through hole 6a. The second lead terminal 7b is inserted into the second through hole 6b. The first lead terminal 7a and the second lead terminal 7b pass through the base plate 1a.
[0047] One end of each of the first lead terminal 7a and the second lead terminal 7b is located inside the body housing 4 (more specifically, inside the main body portion 4d). One end of the first lead terminal 7a is connected to the anode foil 11. One end of the second lead terminal 7b is connected to the cathode foil 12.
[0048] The other ends of the first lead terminal 7a and the second lead terminal 7b are each led out to the outside of the body housing 4 (outer than the opening 3 of the body housing 4). The detailed structure of the first lead terminal 7a is as follows.
[0049] like Figure 2As shown, the first lead terminal 7a has a first component 21 and a second component 22. The first component 21 is formed of aluminum, for example. The second component 22 is formed of a CP wire, for example, by providing a copper layer on the outer peripheral surface of an iron wire.
[0050] The first component 21 has a first round bar portion 15a, a first rib portion 15b, a first weld portion 15c, and a flat plate portion 25. The first round bar portion 15a is formed in a cylindrical shape. The first round bar portion 15a, the first rib portion 15b, and the first weld portion 15c are formed using the shape of the round bar (e.g., a cylindrical aluminum material) that forms the first component 21.
[0051] The first round bar portion 15a is pressed (interference-fitted) into the first through hole 6a. The first round bar portion 15a is located at a position overlapping with the narrowed portion 4a in the Z direction. The diameter (diameter d3) of the first round bar portion 15a is greater than the width (perpendicular to the diameter d3) of the first welded portion 15c. Figure 1 The length of the direction parallel to the plane indicated by arrow Z-Z'.
[0052] The first rib 15b is formed at the end of the plate portion 25 relative to the first round bar portion 15a. The second component 22 is extended outside the main body housing 4.
[0053] The first weld portion 15c is located on the lower side (circuit board 2 side) of the first round bar portion 15a in the Z direction, and is the weld portion of the first component 21 and the second component 22. The first weld portion 15c is formed such that its width increases from the lower end in the Z direction upwards. The diameter d4 of the first lead terminal 7a on the other end side (the end side leading out to the outside of the body housing 4) is smaller than the diameter d3 of the first round bar portion 15a compared to the first weld portion 15c.
[0054] The flat plate 25 is formed as an elongated thin plate, and the width of the flat plate 25 is constant throughout its front end compared to the first rib 15b. The flat plate 25 is formed by stamping one end of the round bar that forms the first component 21 and cutting off the unwanted portion. The first rib 15b is also formed during the stamping process.
[0055] The second component 22 is a tin-plated CP wire. The second component 22 is inserted into a hole (not shown) provided in the first soldering portion 15c of the first component 21 for soldering. Thus, the first component 21 and the second component 22 are mechanically and electrically fixed together. The second component 22 has a first bent portion 16 (first fixing portion) located at the end opposite to the first component 21.
[0056] return Figure 1The first bent portion 16 extends downward along the Z direction from the lower end of the first welded portion 15c and bends outward along the circuit board 2 toward the electrolytic capacitor 1. The portion of the first lead terminal 7a from the first bent portion 16 to the other end is welded to the circuit board 2.
[0057] The detailed structure of the second lead terminal 7b is as follows. Figure 2 As shown, the second lead terminal 7b has a third component 23 and a fourth component 24. The third component 23 is formed, for example, of aluminum. The fourth component 24 is formed, for example, of a CP wire having a copper layer disposed on the outer peripheral surface of an iron wire.
[0058] The third component 23 has a second round bar portion 17a, a rib portion 17b, a second weld portion 17c, and a flat plate portion 26. The second round bar portion 17a is formed in a cylindrical shape. The second round bar portion 17a, the second rib portion 17b, and the second weld portion 17c are formed using the shape of the round bar (e.g., a cylindrical aluminum material) that forms the third component 23.
[0059] The second round bar portion 17a is pressed (interference-fitted) into the second through hole 6b. The second round bar portion 17a is located at a position overlapping with the narrowed portion 4a in the Z direction. The diameter of the second round bar portion 17a (the diameter d5 of the second round bar portion 17a) is greater than the width of the second welded portion 17c.
[0060] The second rib 17b is formed at the end of the plate portion 26 relative to the second round bar portion 17a. The fourth component 24 is extended outside the main body housing 4.
[0061] The second weld portion 17c is located on the lower side (circuit board 2 side) of the second round bar portion 17a in the Z direction, and is the weld portion between the third component 23 and the fourth component 24. The second weld portion 17c is formed such that its lower end in the Z direction widens as it moves upward from the junction with the fourth component 24. The diameter d4 of the second lead terminal 7b on its other end side (the end side extending to the outside of the main body housing 4) is smaller than the diameter d5 of the second round bar portion 17a compared to the second weld portion 17c.
[0062] The flat plate 26 is formed as an elongated thin plate, and the width of the flat plate 26 is constant across its entire front end compared to the second rib 17b. The flat plate 26 is formed by stamping one end of the round bar that forms the third component 23 and cutting off any unwanted portions. The second rib 17b is also formed during the stamping process.
[0063] The fourth component 24 is a tin-plated CP wire. The fourth component 24 is inserted into a hole (not shown) provided in the second welding portion 17c of the third component 23 for welding. Thus, the third component 23 and the fourth component 24 are mechanically and electrically fixed. The fourth component 24 has a second bent portion 18 (second fixing portion) located at the end opposite to the third component 23. The diameter d6 of the fourth component 24 is smaller than the diameter d5 of the second round bar portion 17a.
[0064] return Figure 1 The second bend 18 extends downward along the Z direction from the lower end of the second soldering portion 17c and bends outward along the circuit board 2 toward the electrolytic capacitor 1. The portion of the second lead terminal 7b from the second bend 18 to the other end is soldered onto the circuit board 2.
[0065] The external pressure deformation suppressing plate 8 is formed from a synthetic resin plate incorporating reinforcing materials (glass fiber, cellulose fiber, ceramics, etc.). For example, the external pressure deformation suppressing plate 8 is formed from phenolic resin (registered trademark).
[0066] The external pressure deformation suppression plate 8 is an elliptical plate-like body with a minor axis d9 and a major axis d10 when viewed from above along the Z direction (see below). Figure 5 , Figure 6 The minor axis d9 of the external pressure deformation suppression plate 8 is parallel to the X direction. The major axis d10 of the external pressure deformation suppression plate 8 is parallel to the Y direction.
[0067] like Figure 1 , Figure 2 As shown, the sealing member 6 side surface of the external pressure deformation suppression plate 8 abuts against the opening side end face 6r in a slidable state. The side of the external pressure deformation suppression plate 8 opposite to the sealing member 6 faces the front end of the bent portion 4b in the Z direction. The external pressure deformation suppression plate 8 and the front end of the bent portion 4b abut against each other or face each other with a small gap in the Z direction.
[0068] The external pressure deformation suppression plate 8 has a third through hole 8c, a fourth through hole 8d, a pair of retaining portions 8a, and a pair of outer peripheral extension portions 8b (see below). Figure 5 ).
[0069] The third through hole 8c and the fourth through hole 8d are holes that penetrate the external pressure deformation suppression plate 8 along the thickness direction (=Z direction). The third through hole 8c and the fourth through hole 8d are arranged along the X direction. In the X and Y directions, the center of the third through hole 8c is located at the same position as the center of the first through hole 6a (see below). Figure 5 In both the X and Y directions, the center of the fourth through hole 8d is located at the same position as the center of the second through hole 6b (see below). Figure 5 ).
[0070] The first lead terminal 7a is inserted into the third through hole 8c. The inner diameter d7 of the third through hole 8c is larger than the diameter d4 of the first lead terminal 7a. Therefore, there is a gap a3 between the first lead terminal 7a and the inner circumferential surface of the third through hole 8c.
[0071] The second lead terminal 7b is inserted into the fourth through hole 8d. The inner diameter d8 of the fourth through hole 8d is larger than the diameter d6 of the second lead terminal 7b. Therefore, there is a gap a4 between the second lead terminal 7b and the inner circumferential surface of the fourth through hole 8d.
[0072] The inner diameter d7 of the third through hole 8c is smaller than the diameter d3 of the first round bar portion 15a. In the Z direction, the edge portion 8m of the third through hole 8c located on the sealing member 6 side is positioned lower than the first round bar portion 15a. The edge portion 8m and the first weld portion 15c face each other in the Z direction. The inner diameter d8 of the fourth through hole 8d is smaller than the diameter d5 of the second round bar portion 17a. In the Z direction, the edge portion 8n of the fourth through hole 8d located on the sealing member 6 side is positioned lower than the second round bar portion 17a. The edge portion 8n and the second weld portion 17c face each other in the Z direction.
[0073] A pair of retaining portions 8a are located on both sides of the external pressure deformation suppressing plate 8 in the X direction (the portion overlapping with the outer periphery of the external pressure deformation suppressing plate 8). In the X direction, the retaining portions 8a are located further inward than the retaining portions 6c and 6d. The retaining portions 8a may also be formed on the entire outer periphery of the external pressure deformation suppressing plate 8.
[0074] The outer peripheral surfaces of a pair of held portions 8a (the surfaces of the held portions 8a parallel to the Z direction) abut against the inner peripheral surfaces of the held portions 6c and 6d (the surfaces of the held portions 6c and 6d orthogonal to the opening-side end face 6r). The outer peripheral surfaces of the pair of held portions 8a are rougher than the surfaces of the capacitor element 5 side of the external pressure deformation suppression plate 8. Thus, by inserting the seal 6 into the hole or groove in the rough surface, the outer peripheral surfaces of each held portion 8a are engaged with the inner peripheral surfaces of the held portions 6c and 6d through an anchoring effect.
[0075] Through the retaining portions 6c and 6d, the pressing force with the elastic coefficient corresponding to the seal 6 acts in the X direction toward the external pressure deformation suppression plate 8 (more specifically, the retaining portion 8a). As a result, the external pressure deformation suppression plate 8 is held by the retaining portions 6c and 6d. Thus, the external pressure deformation suppression plate 8 is attached to and held by the retaining portions 6c and 6d, thereby retaining the seal 6.
[0076] The engagement points of the pair of retained portions 8a and 6c, 6d are located further outward in the X direction compared to the opening 3. It should be noted that the detailed structure of the pair of peripheral extensions 8b will be described later.
[0077] Due to reflow soldering and other processes during installation on the circuit board 2, the internal pressure of the electrolytic capacitor 1 increases, and the seal 6 is pressed towards the circuit board 2 side in the Z direction. In this situation, the external pressure deformation suppression plate 8 abuts against the front end of the bending portion 4b, thereby restricting the movement of the seal 6 towards the circuit board 2 side in the Z direction. Even if the seal 6 deforms or moves, the seal 6 can slide against the abutting body housing, the first round bar portion 15a, the second round bar portion 17a, and the component-side end face 6r of the external pressure deformation suppression plate 8, thus suppressing the reduction of the sealing effect of the seal 6.
[0078] After reflow soldering, the portion of the first lead terminal 7a from the first bend 16 to the other end is soldered and fixed to the circuit board 2. Additionally, the portion of the second lead terminal 7b from the second bend 18 to the other end is soldered and fixed to the circuit board 2.
[0079] Figure 4 This is a diagram showing the state in which the electrolytic capacitor 1 has been molded. (See diagram for example.) Figure 4 As shown, the periphery of the electrolytic capacitor 1 can be molded together with the circuit board 2 using molding resin 9. Molding the periphery of the electrolytic capacitor 1 improves its water resistance, moisture resistance, oil resistance, chemical resistance, dust resistance, and vibration resistance. Molding using molding resin 9, as... Figure 4 As shown, the electrolytic capacitor 1 side (surface side) of the electrolytic capacitor 1 and the circuit board 2 can be molded with molding resin 9, and the back side of the circuit board 2 can also be molded together (illustration omitted).
[0080] When molding around the electrolytic capacitor 1, a mold is prepared to cover the area to be molded, and molding resin 9 is injected into the mold. At this time, the injection pressure of the molding resin 9 is ( Figure 4 The white arrow shown acts on electrolytic capacitor 1.
[0081] Specifically, when the molding resin is injected, the following pressures are applied: a pressing pressure on the inside of the body housing 4 along the Z direction of the top 4c; a pressing pressure on the capacitor element 5 side (inside of the body housing 4) along the X direction of the side of the body housing 4 (main body 4d, narrowing part 4a and bending part 4b); and a pressing pressure on the capacitor element 5 side (inside of the body housing 4) along the Z direction of the external pressure deformation suppression plate 8 and the sealing member 6.
[0082] As mentioned above, when the top 4c is pressed toward the inside of the main body housing 4 along the Z direction (when the top 4c is pressed toward the capacitor element 5), the movement of the main body housing is restricted because the lower end 4e of the bent portion 4b is close to and faces the surface of the seat plate 1a in the Z direction, thus suppressing any adverse effects on the capacitor element.
[0083] As previously described, when the external pressure deformation suppression plate 8 is pressed towards the capacitor element side (opposite to the circuit board 2) along the Z direction, the edge portion 8m of the third through hole 8c and the 8n of the fourth through hole 8d of the external pressure deformation suppression plate 8 abut against the first solder portion 15c of the first lead terminal 7a and the second solder portion 17c of the second lead terminal, which have a fixing portion fixed to the circuit board 2, respectively, thereby restricting movement.
[0084] Thus, even if the external pressure deformation suppression plate 8 and the seal 6 are pressed in the Z direction due to molding injection, the movement of the external pressure deformation suppression plate 8 is restricted, and the movement of the seal 6 towards the capacitor element in the Z direction is also restricted. Therefore, the force of the seal 6 pressing on the capacitor element 5 is less likely to have an effect, and adverse effects on the capacitor element 5 can be suppressed.
[0085] Furthermore, as mentioned earlier, the end face 6r on the open side and the end face on the sealing member 6 side of the external pressure deformation suppression plate 8 can slide. Therefore, depending on the environment in which the electrolytic capacitor 1 is arranged, the sealing member 6 easily deforms along with the expansion / contraction of the electrolytic capacitor 1. That is, when the sealing member 6 deforms, the external pressure deformation suppression plate 8 has difficulty hindering the deformation of the sealing member 6. Therefore, even if the electrolytic capacitor 1 expands / contracts, the reduction in the sealing effect of the sealing member 6 can be suppressed.
[0086] Furthermore, as mentioned above, there is a gap a3 between the inner circumferential surface of the first lead terminal 7a and the third through hole 8c, and a gap a4 between the inner circumferential surface of the second lead terminal 7b and the fourth through hole 8d. Therefore, even if the seal 6 moves slightly in the Z direction, the friction between the first lead terminal 7a and the second lead terminal 7b and the seal 6 is minimal. Thus, damage to the first lead terminal 7a and the second lead terminal 7b can be suppressed. Furthermore, this can prevent the tin plating applied to the surface of the first lead terminal 7a on the side opposite to the first solder portion 15c, and the surface of the second lead terminal 7b on the side opposite to the second solder portion 17c, from peeling off due to friction with the seal 6.
[0087] Furthermore, as mentioned earlier, a gap a1 exists between the inner surfaces of the retaining portions 6c and 6d and the bending portion 4b. Moreover, the gap a1 gradually increases from the capacitor element 5 side of the retaining portions 6c and 6d towards the opening portion 3 side. Therefore, the pressing pressure applied to the retaining portion 6c during the injection of the molding resin 9 tends to be directed in a direction parallel to the external pressure deformation suppression plate 8 (along the X direction). Consequently, the outer periphery of the external pressure deformation suppression plate 8 is firmly held by the retaining portion 6c. Thus, even if the seal 6 deforms or moves towards the capacitor element 5 side (inner side of the body housing 4) due to the pressing pressure of the molding resin 9, the external pressure deformation suppression plate 8 restricts the movement of the seal 6. As a result, it is possible to prevent the distance between the body side end face 6q of the seal 6 and the capacitor element 5 from approaching, and to suppress any adverse effects on the capacitor element 5.
[0088] As previously stated, the width of the isolator 10 in the Z direction is greater than the width of the anode foil 11 and the cathode foil 12. Therefore, even assuming the seal 6 presses against the capacitor element 5, the isolator 10 acts as a buffer, making it difficult to apply force to the anode foil 11 and the cathode foil 12. Thus, damage to the width of the anode foil 11 and the cathode foil 12 can be suppressed.
[0089] <Preferred Structure of Seal 6 and External Pressure Deformation Suppression Plate 8>
[0090] Next, the preferred structure of the seal 6 and the external pressure deformation suppression plate 8 will be described.
[0091] Figure 5 This is a top view of the seal 6 and the external pressure deformation suppression plate 8 from the opening side end face 6r along the Z direction. Figure 6 This is a perspective view of the seal 6 and the external pressure deformation suppression plate 8. (See diagram below.) Figure 5 , Figure 6 As shown, in addition to the above structure, the seal 6 has cutouts 6t and 6u. The cutouts 6t and 6u are cuts formed along the periphery of the seal 6 by a retaining portion 6c, an opening-side end face 6r, and a retaining portion 6d. The cutouts 6t and 6u are formed in a shape that cuts along the periphery of the seal 6 between the retaining portion 6c and the retaining portion 6d. An external pressure deformation suppression plate 8 is inserted into the cutouts 6t and 6u.
[0092] The load deflection temperature of the external pressure deformation suppression plate 8 (measured according to Method A (1.82 MPa) of American Society for Testing and Materials standard "D648") is above 140°C and below 240°C. The load deflection temperature is adjusted according to the synthetic resin board, the added reinforcing material, and the amount of reinforcing material added. By using such an external pressure deformation suppression plate 8, when the ambient temperature of the electrolytic capacitor 1 rises (220°C to 260°C) during reflow soldering, even if the stress caused by the increased pressure inside the electrolytic capacitor 1 (i.e., inside the body shell 4) and the deformation of the seal 6 is applied to the external pressure deformation suppression plate 8, due to the decrease in rigidity of the external pressure deformation suppression plate 8, the central part of the external pressure deformation suppression plate 8 (i.e., the area surrounding the center O, including the center O) will undergo elastic deformation and deflection towards the circuit board 2 side, accompanied by plastic deformation. That is, when the seal 6 deforms, the external pressure deformation suppression plate 8 is unable to prevent the deformation of the seal 6, thus suppressing cracks, fractures, and damage to the external pressure deformation suppression plate 8. Furthermore, at the molding temperature during molding (e.g., 120°C to 180°C), the rigidity of the external pressure deformation suppression plate 8 is maintained at a high level. This suppresses deformation of the external pressure deformation suppression plate 8 and the seal 6 in response to resin injection pressure, preventing damage to the capacitor element 5. Moreover, due to the plastic deformation during reflow soldering, the central portion of the external pressure deformation suppression plate 8 is bent towards the circuit board 2, thus increasing its strength in response to resin injection pressure compared to a flat surface, further suppressing damage to the capacitor element 5.
[0093] Furthermore, the external pressure deformation suppression plate 8 is preferably 0.5mm to 1.5mm thick. If it is thinner than 0.5mm, its rigidity against the injection pressure of the molding resin will be weakened. If it is thicker than 1.5mm, even when a large internal pressure rise occurs during reflow soldering, the elastic deformation of the external pressure deformation suppression plate will be small, and the main body shell 4 will be at risk of deformation.
[0094] A pair of held portions 8a are located on a straight line L1 drawn through the center of the first through hole 6a and the center of the second through hole 6b. That is, a pair of held portions 8a, the first through hole 6a and the second through hole 6b are arranged on the straight line L1. The central portion of the held portion 8a in the Y direction (vertex P2 described later) is located on the straight line L1. This will be explained in more detail below.
[0095] The end of the retaining part 8a in the X direction (the outermost part of the external pressure deformation suppression plate 8 in the X direction) is designated as vertex P2. Vertex P2 is located on line L1. Additionally, as... Figure 2As shown, vertex P2 is located further inside the body shell 4 in the X direction than vertex P1. Furthermore, vertex P2 is located further outward in the X direction than the edge of opening 3. It should be noted that the aforementioned minor axis d9 can be considered as the distance between vertices P2 in the X direction.
[0096] like Figure 5 , Figure 6 As shown, in addition to the above-described structure, the external pressure deformation suppression plate 8 also has an outer peripheral extension 8b. The outer peripheral extension 8b is connected to the retained portion 8a along the outer periphery of the seal 6. In the X direction, the outer peripheral extension 8b is located between a pair of retained portions 8a.
[0097] Here, a line orthogonal to line L1 and drawn through the center O in the X and Y directions of the external pressure deformation suppression plate 8 is designated as line L2. A pair of peripheral extensions 8b lie on line L2.
[0098] In the Y direction, the outer peripheral extension 8b protrudes further outward than the apex P1 of the narrowing portion 4a. A more detailed description of the outer peripheral extension 8b follows.
[0099] Figure 7 It shows along Figure 6 The cross-sectional view shown is obtained by cutting the electrolytic capacitor 1 with straight line L2. Figures 5-7 As shown, the straight line L3 is located at a position in the X direction that overlaps with the end of the outer peripheral extension 8b in the Y direction (the outermost part of the external pressure deformation suppression plate 8 in the Y direction). More specifically, it is more preferable for the end of the outer peripheral extension 8b in the Y direction to be closer to the center of the outer peripheral extension 8b in the X direction, and even more preferable for it to be closer to the straight line L2.
[0100] As previously described, in the Y direction, the end of the outer peripheral extension 8b is located further outward than the vertex P1 of the main body housing 4. Therefore, when the external pressure deformation suppression plate 8 is subjected to the injection pressure of the molding resin 9, the inner surface of the narrowing portion 4a of the main body housing 4 supports the outer peripheral extension 8b. As a result, the external pressure deformation suppression plate 8 (and consequently the seal 6) can be further suppressed from being pressed into the capacitor element 5 side (inner side of the main body housing 4) in the Z direction.
[0101] Furthermore, as previously described, the components are arranged in the following order along the straight line L1: retaining part 6c, retained part 8a, third through hole 8c, fourth through hole 8d, retained part 8a, and retaining part 6d. In other words, in the X direction, the second component 22 and the fourth component 24 are located between a pair of retained parts 8a.
[0102] Furthermore, as mentioned earlier, lines L1 and L2 are orthogonal. In other words, the first through hole 6a, the second through hole 6b, the retained portion 8a, and the retaining portions 6c and 6d arranged on line L1 are orthogonal to the outer peripheral extension portion 8b arranged on line L2. Therefore, the seal 6 is difficult to deform in the X direction due to the contact between the retaining portions 6c and 6d and the retained portion 8a, and in the Y direction due to the contact between the outer peripheral extension portion 8b and the opening-side end face 6r.
[0103] <Variation Example>
[0104] Furthermore, this invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of this invention. For example, as a preferred structure of the external pressure deformation suppression plate 8, it is elliptical in plan view, but is not limited thereto. Specifically, it can be a shape other than an elliptical shape (e.g., a hexagon, a rhomboid quadrilateral, or other polygon) where the distance from the center O to the front end of the outer peripheral extension 8b in the Y direction is greater than the distance from the center O to the front end of the held portion 8a in the X direction. It can also be a circle without the outer peripheral extension 8b.
[0105] <Postscript>
[0106] The electrolytic capacitor (1) comprises: a body shell (4) formed as a bottomed cylindrical shape with one end closed and an opening (3) formed at the other end; a capacitor element (5) housed within the body shell (4); a sealing member (6) having a first through hole (6a) and a second through hole (6b) arranged along a first direction (X-X'), disposed inside the body shell (4) and sealing the opening (3); and an external pressure deformation suppression plate (8) which is slidably disposed abutting against the end face (6r) of the opening (3) side of the sealing member (6), in the first direction (X-X') and in the direction of the opening (X-X'). A third through hole (8c) overlapping the first through hole (6a) is formed in the orthogonal second direction (Y-Y'), and a fourth through hole (8d) overlapping the second through hole (6b) is formed in the first direction (X-X') and the second direction (Y-Y'); a first lead terminal (7a), which is connected to the capacitor element (5) inside the body housing (4), is led out to the outside of the body housing (4) through the first through hole (6a) and the third through hole (8c); a second lead terminal (7b), which is connected to the capacitor element (5) inside the body housing (4), is led out through the second through hole (6b) and the fourth through hole (8d). Outside the main body housing (4); and a base plate (1a), which approaches and faces the end (4e) of the main body housing (4) on a third direction (ZZ′) orthogonal to the first direction (XX′) and the second direction (YY′), and welds a first lead terminal (7a) and a second lead terminal (7b), the first lead terminal (7a) having: a first round bar portion (15a) located inside the first through hole (6a), the outer diameter (d3) being larger than the inner diameter (d7) of the third through hole (8c); a first weld portion (15c) located on the opening (3) side of the first round bar portion (15a) on the third direction (ZZ′). The end portion; the first fixing portion (16), located outside the body housing (4), is welded to the base plate (1a); the second lead terminal (7b) has: a second round bar portion (17a), located inside the second through hole (6b), with an outer diameter (d5) larger than the inner diameter (d8) of the fourth through hole (8d); a second welding portion (17c), located at the end of the second round bar portion (17a) on the side of the opening (3) in the third direction (ZZ′); the second fixing portion (18), located outside the body housing (4), is welded to the base plate (1a); the body housing (4) has: a main body portion (4d), which houses the electrolytic capacitor (1) inside;A narrowing portion (4a) extends from the main body portion (4d) to the opening (3), with an inner diameter (d1) smaller than the inner diameter (d2) of the main body portion (4d). A seal (6) is located at a position overlapping the narrowing portion (4a) in the third direction (ZZ′). When the seal (6) is pressed towards the capacitor element (5) along the third direction (ZZ′), the edge (8m) of the third through hole (8c) abuts against the first weld portion (15c), and the edge (8n) of the fourth through hole (8d) abuts against the second weld portion (17c), thereby restricting its movement towards the capacitor element (5). Gaps (a3, a4) exist between the first lead terminal (7a) and the third through hole (8c), and between the second lead terminal (7b) and the fourth through hole (8d) (first structure).
[0107] In the electrolytic capacitor (1) of the first structure, the capacitor element (5) has: an anode foil (11); an isolation member (10) overlapping the anode foil (11); and a cathode foil (12) facing the anode foil (11) across the isolation member (10). The anode foil (11), the isolation member (10) and the cathode foil (12) are wound together. A first lead terminal (7a) connects one end of itself to the anode foil (11) and leads the other end to the outside of the body housing (4). A second lead terminal (7b) connects one end of itself to the cathode foil (12) and leads the other end to the outside of the body housing (4). The width of the isolation member (10) in the third direction (Z-Z') is greater than the respective widths of the cathode foil (12) and the anode foil (11) in the third direction (Z-Z'). The cathode foil (12) and the anode foil (11) are arranged further inside the two ends of the isolation member (10) in the third direction (Z-Z') (second structure).
[0108] In the electrolytic capacitor (1) of the first or second structure, the body shell (4) has a bent portion (4b) that bends from the narrowed portion (4a) toward the inside of the body shell (4) and extends to the opening (3), and the end of the third direction (ZZ′) approaches or abuts against the end face (6r) of the opening side in the third direction (ZZ′) (third structure).
[0109] In the electrolytic capacitors (1) of the first to third structures, the sealing part has a pair of retaining parts (6c, 6d). The pair of retaining parts (6c, 6d) protrude from the periphery of the opening-side end face (6r) toward the opening (3) in a third direction (Z-Z') and are provided on both sides of the external pressure deformation suppression plate (8) in a first direction (X-X'). The external pressure deformation suppression plate (8) has a pair of retained parts (8a) and a pair of outer peripheral extensions (8b). The pair of retained parts (8a) face and abut against each retaining part (6c, 6d) in the first direction (X-X'), and the pair of outer peripheral extensions (8b) are connected to each retained part (8a). Located between each holding part (6c, 6d) in the first direction (X-X'), and at each end of the external pressure deformation suppression plate (8) in the second direction (Y-Y'), when viewed from above along the third direction (Z-Z'), the second distance from the center part (O) of the external pressure deformation suppression plate (8) in the first direction (X-X') and the end of the holding part (8a) in the first direction (X-X') is longer than the second distance from the center part (O) to the end of the outer peripheral extension part (8b) in the second direction (Y-Y') (fourth structure).
[0110] In the electrolytic capacitor (1) of the fourth structure, each holding part (6c, 6d) is arranged on a first straight line (L1) drawn in such a way that it passes through the center of the first through hole (6a) and the center of the second through hole (6b), and one is arranged on each side of the first through hole (6a) and the second through hole (6b) sandwiched in the middle. A second straight line (L2) drawn in such a way that it passes through each of the outer peripheral extensions (8b) is orthogonal to the first straight line (L1) (fifth structure).
[0111] In the electrolytic capacitor (1) of the fifth structure, the intersection of the first straight line (L1) and the second straight line (L2) is located at a position that overlaps with the center part (O) (sixth structure).
[0112] In the electrolytic capacitor (1) of the sixth structure, the second straight line (L2) passes through each peripheral extension (8b) at the end in the second direction (Y-Y') (seventh structure).
[0113] In the electrolytic capacitor (1) of the fourth structure, the sealing member (6) is circular in the state of being viewed from above along the third direction (Z-Z'), and the external pressure deformation suppression plate (8) is elliptical cylindrical in the state of being viewed from above along the third direction (Z-Z'), having a short axis (d9) parallel to the first direction (X-X') and a long axis (d10) parallel to the second direction (Y-Y'), and each of the holding parts (8a) is located at both ends of the external pressure deformation suppression plate (8) along the short axis (d9) (eighth structure).
[0114] In the electrolytic capacitor (1) of the eighth structure, each peripheral extension (8b) is located at both ends of the external pressure deformation suppression plate (8) along the long axis (d10) (ninth structure).
[0115] In any of the electrolytic capacitors (1) of the first to ninth structures, the external pressure deformation suppression plate (8) has a load strain temperature above 140°C and below 240°C as measured according to ASTM D648.
Claims
1. An electrolytic capacitor, characterized in that, have: The main body shell is formed as a bottomed cylindrical shape with one end closed and an opening formed at the other end; Capacitor elements are housed within the main body housing; A sealing element having a first through hole and a second through hole arranged in a first direction, disposed inside the body housing and sealing the opening; An external pressure deformation suppression plate is configured to abut against the end face of the opening side of the seal in a slidable state. A third through hole overlapping the first through hole is formed in the first direction and the second direction orthogonal to the first direction, and a fourth through hole overlapping the second through hole is formed in the first direction and the second direction. The first lead terminal is connected to the capacitor element inside the main body housing, and is led out to the outside of the main body housing through the first through hole and the third through hole; The second lead terminal is connected to the capacitor element inside the main body housing, and is led out to the outside of the main body housing through the second through hole and the fourth through hole; as well as The seat plate, which approaches and faces the end of the main body housing on the opening side in a third direction orthogonal to the first and second directions, The first lead terminal has: The first round bar portion is located inside the first through hole, and its outer diameter is larger than the inner diameter of the third through hole; A first welded portion, located at the end of the first round bar portion on the opening side in the third direction; and The first fixing part, located outside the main body housing, is soldered onto the circuit board. The second lead terminal has: The second round bar portion is located inside the second through hole, and its outer diameter is larger than the inner diameter of the fourth through hole; The second welded portion is located at the end of the second round bar portion on the third-direction opening side; and The second fixing part, located outside the main body housing, is soldered to the circuit board. The body shell has: The main body internally houses the capacitor element; as well as The narrowing portion extends from the main body to the opening, and its inner diameter is smaller than that of the main body. The seal is located at a position that overlaps with the narrowing portion in the third direction. When the seal is pressed towards the capacitor element side along the third direction, the edge of the third through hole abuts against the first welded portion, and the edge of the fourth through hole abuts against the second welded portion, thereby restricting the movement of the seal towards the capacitor element side. There are gaps between the first lead terminal and the third through hole, and between the second lead terminal and the fourth through hole.
2. The electrolytic capacitor according to claim 1, characterized in that, The capacitor element has: Anode foil; The separator overlaps with the anode foil; as well as The cathode foil faces the anode foil, separated by the spacer. The anode foil, the spacer, and the cathode foil are wound together. The first lead terminal connects one end to the anode foil and extends the other end to the outside of the body housing. The second lead terminal connects one end to the cathode foil and extends the other end to the outside of the main body housing. The width of the spacer in the third direction is greater than the respective widths of the cathode foil and the anode foil in the third direction. The cathode foil and the anode foil are configured to be further inward than the two ends of the separator in the third direction.
3. The electrolytic capacitor according to claim 1, characterized in that, The body housing has a bent portion that bends from the narrowed portion toward the inside of the body housing and extends to the opening, wherein the third-direction end approaches or abuts the opening-side end face in the third-direction direction to be opposite to the opening-side end face.
4. The electrolytic capacitor according to claim 1, characterized in that, The seal has a pair of retaining portions that protrude from the periphery of the opening-side end face toward the opening side in a third direction. One retaining portion is provided on each side of the external pressure deformation suppression plate in the first direction. The external pressure deformation suppression plate has the following characteristics: A pair of held portions, which face and abut against each of the holding portions in the first direction; as well as An outer peripheral extension is connected to each of the held portions and is located between each of the held portions in the first direction. One of the outer peripheral extensions is located at each end of the external pressure deformation suppressing plate in the second direction. When the external pressure deformation suppression plate is viewed from above along the third direction, the first distance from the center of the external pressure deformation suppression plate in the first and second directions to the end of the retained portion in the first direction is longer than the second distance from the center to the end of the peripheral extension portion in the second direction.
5. The electrolytic capacitor according to claim 4, characterized in that, Each of the aforementioned retaining portions is arranged on a first straight line drawn so as to pass through the center of the first through hole and the center of the second through hole, and one is arranged on each side at a position that sandwiches the first through hole and the second through hole in the middle. The second straight line drawn in such a way that it passes through each of the said peripheral extensions is orthogonal to the first straight line.
6. The electrolytic capacitor according to claim 5, characterized in that, The intersection of the first straight line and the second straight line is located at a position that overlaps with the center portion.
7. The electrolytic capacitor according to claim 6, characterized in that, The second straight line passes through the ends of each of the said peripheral extensions in the second direction.
8. The electrolytic capacitor according to claim 4, characterized in that, Viewed from above along the third direction, the seal is circular in shape. Viewed from above along the third direction, the external pressure deformation suppression plate is elliptical cylindrical in shape, and has a minor axis parallel to the first direction and a major axis parallel to the second direction. Each of the retained portions is located at both ends of the external pressure deformation suppression plate along the short axis.
9. The electrolytic capacitor according to claim 8, characterized in that, Each of the aforementioned peripheral extension portions is located at both ends of the external pressure deformation suppression plate along the long axis.
10. The electrolytic capacitor according to any one of claims 1 to 9, characterized in that, The external pressure deformation suppression plate has a load strain temperature above 140°C and below 240°C as measured according to ASTM D648 standard.