Electrolytic capacitor

Abstract

To suppress reduction of sealing effect of sealing material and furthermore to suppress adverse effect on a capacitor element and on a lead terminal.SOLUTION: An electrolytic capacitor comprises: a capacitor element; a sealing material in which a first through-hole and a second through-hole are formed; a plate for suppression of deformation due to outer pressure which is disposed slidably while being abutted on an opening-side end face of the sealing material and in which a third through-hole and a fourth through-hole are formed; a first lead terminal; a second lead terminal; and a seat plate. The first lead terminal includes a first round rod part, a first welded part, a first rib part, and a first fixed part. The second lead terminal includes a second round rod part, a second welded part, a second rib part, and a second fixed part. A main body case includes a trunk part and a throttled part . In the sealing material, an edge of the third through-hole is abutted to the first welded part and an edge of the fourth through-hole is abutted to the second welded part, thereby regulating movement of the sealing material to the side of the capacitor element. There are gaps between the first lead terminal and the third through-hole and between the second lead terminal and the fourth through-hole.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an electrolytic capacitor. [Background technology]

[0002] There is an electrolytic capacitor that includes a main case, a capacitor element, a sealing material, and lead terminals. The main case is cylindrical with one end closed and the other end open, and the capacitor element is housed within the main case. The sealing material is plate-shaped and seals the opening of the main case. The capacitor element includes an anode foil, a separator, and a cathode foil. The anode foil and the cathode foil face each other with the separator interposed therebetween.

[0003] The capacitor element is formed by winding an anode foil, a separator, and a cathode foil. The capacitor element contains at least one of an electrolytic solution and a solid electrolyte. One end of a lead terminal is connected to each of the anode foil and the cathode foil. The other end of the lead terminal penetrates the sealing material and is drawn out to the opening of the main case.

[0004] Some electrolytic capacitors have a plate-shaped accessory bonded to the end face of the sealing material on the opening side of the main case (Patent Document 1). The sealing material and the accessory are bonded together at all of their contacting surfaces, forming a single unit. The outer diameter of the accessory is configured to be approximately equal to the outer diameter of the sealing material. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 08-293435 Summary of the Invention [Problem to be solved by the invention]

[0006] Depending on the environment in which the electrolytic capacitor is placed, the pressure inside the main case or the external pressure may fluctuate, causing the sealant to deform. As mentioned above, the attachment is attached to the end face of the sealant on the opening side. This prevents the sealant from deforming, making it difficult for the sealant to follow the expansion / contraction of the electrolytic capacitor due to pressure fluctuations inside the main case. This may reduce the sealant's sealing effectiveness.

[0007] An example of the aforementioned environment is when an electrolytic capacitor is soldered to be mounted on a circuit board. Specifically, in this case, the heat generated by soldering vaporizes components inside the main case (e.g., electrolyte solution, solid electrolyte components, or moisture contained in the capacitor element), increasing the pressure inside the main case and causing the electrolytic capacitor to expand. Furthermore, when this occurs, the expanded electrolytic capacitor may shrink back to its original state when cooled to room temperature after soldering is completed. When the pressure inside the main case increases, the sealing material may deform and be pushed out of the main case through the opening. The effects of heat are particularly significant when reflow soldering is performed.

[0008] Furthermore, the encapsulant may unintentionally move from its fixed position depending on the environment in which the electrolytic capacitor is placed. One example of such an environment is when the electrolytic capacitor is molded with a molding resin. In such a case, the encapsulant is pressed toward the capacitor element (inside the main case) due to the pressure generated when the molding resin is injected. This pressure may cause the encapsulant to deform or be pushed toward the capacitor element (inside the main case), causing it to move from its fixed position.

[0009] As mentioned above, if the encapsulant moves from its fixed position toward the capacitor element, the encapsulant may press against the capacitor element, potentially adversely affecting the capacitor element. Furthermore, if the encapsulant moves from its fixed position, the encapsulant's sealing effectiveness may be reduced. Furthermore, if the encapsulant moves, the lead terminals may be adversely affected.

[0010] Therefore, an object of the present invention is to provide an electrolytic capacitor that can suppress a decrease in the sealing effect of the sealing material while suppressing adverse effects on the capacitor element and lead terminals. [Means for solving the problem]

[0011] To achieve the above object, an electrolytic capacitor according to a first aspect of the present invention includes a main case, a capacitor element, a sealing material, an external pressure deformation suppression plate, a first lead terminal, a second lead terminal, and a seat plate. The main case is cylindrical with a bottom, closed at one end and having an opening at the other end. The capacitor element is housed within the main case. The sealing material is disposed inside the main case, which has a first through hole and a second through hole aligned in a first direction, and seals the opening. The external pressure deformation suppression plate is disposed in slidable contact with the opening-side end face of the sealing material, which is the end face on the opening side of the sealing material. The external pressure deformation suppression plate has a third through hole formed therein that overlaps with the first through hole in the first direction and a second direction perpendicular to the first direction, and a fourth through hole formed therein that overlaps with the second through hole in the first direction and the second direction. The first lead terminal is connected to the capacitor element within the main case and extends to the outside of the main case through the first and third through holes. The second lead terminal is connected to the capacitor element inside the main case and extends outside the main case through the second and fourth through holes. The base plate is adjacent to and faces the end of the main case on the opening side in a third direction perpendicular to the first and second directions. The first lead terminal has a first round rod portion located inside the first through hole and having an outer diameter larger than the inner diameter of the third through hole, and a first fixing portion located outside the main case and soldered to the substrate. The second lead terminal has a second round rod portion located inside the second through hole and having an outer diameter larger than the inner diameter of the fourth through hole, and a second fixing portion located outside the main case and soldered to the substrate. The main case has a body portion that houses the electrolytic capacitor and a drawn portion that extends from the body portion to the opening and has an inner diameter smaller than that of the body portion. The encapsulant is positioned to overlap the drawn portion in the third direction. When the sealing material is pressed toward the capacitor element in the third direction, an edge of the third through hole abuts against the first welded portion and an edge of the fourth through hole abuts against the second welded portion, thereby restricting movement toward the capacitor element. A gap exists between the first lead terminal and the third through hole, and between the second lead terminal and the fourth through hole. [Effects of the Invention]

[0012] According to the first configuration of the present invention, the external pressure deformation suppression plate is disposed in slidable contact with the opening end surface of the sealing material. Therefore, even if the sealing material deforms or moves, the external pressure deformation suppression plate slides against the opening end surface of the sealing material, following the deformation of the sealing material. Therefore, the external pressure deformation suppression plate is less likely to hinder the deformation of the sealing material, and a decrease in the sealing effect of the sealing material can be suppressed.

[0013] Furthermore, even if the sealing material is pressed toward the capacitor element in the third direction, its movement toward the capacitor element is restricted. This makes it difficult for the sealing material to move from its fixed position, preventing the capacitor element from being adversely affected by the movement of the sealing material. Furthermore, there are gaps between the first lead terminal and the third through hole and between the second lead terminal and the fourth through hole. This makes it difficult for the sealing material (the inner surfaces of the third through hole and the fourth through hole) to come into contact with the first lead terminal and the second lead terminal, even if the sealing material moves slightly or deforms. This reduces friction between the first lead terminal and the second lead terminal and the sealing material. This prevents the movement of the sealing material from adversely affecting the first lead terminal and the second lead terminal. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a diagram showing a state in which the electrolytic capacitor according to the present embodiment is mounted on a circuit board. [Figure 2] Enlarged cross-sectional view showing the vicinity of the narrowed portion [Figure 3] A perspective view showing the configuration of a capacitor element. [Figure 4] Diagram showing the electrolytic capacitor with the molding around it [Figure 5] Plan view of the sealing material and the external pressure deformation suppression plate from the opening end face along the Z direction [Figure 6] A perspective view of the sealing material and the external pressure deformation suppression plate [Figure 7] A cross-sectional view showing a cross section of the electrolytic capacitor taken along the line L2 shown in Figure 6. DETAILED DESCRIPTION OF THE INVENTION

[0015] <Basic configuration> The basic configuration of an embodiment of the present invention will be described below with reference to the drawings. Figure 1 is a diagram showing an electrolytic capacitor 1 according to this embodiment mounted on a circuit board 2.

[0016] As shown in Fig. 1, the electrolytic capacitor 1 is mounted on a circuit board 2 via a base plate 1a. The direction parallel to the mounting direction of the electrolytic capacitor 1 on the circuit board 2 (the direction parallel to the arrow ZZ' shown in Fig. 1) will be referred to simply as the "Z direction" (= third direction) hereinafter. In each drawing, the direction indicated by the arrow ZZ' is illustrated as the Z direction.

[0017] The electrolytic capacitor 1 includes a main body case 4, a capacitor element 5, a sealing material 6, a first lead terminal 7a, a second lead terminal 7b, and an external pressure deformation suppression plate 8.

[0018] The main body case 4 is made of, for example, aluminum. The main body case 4 is a cylindrical body with one end in the Z direction closed and the other end open. The main body case 4 has a top portion 4c, a body portion 4d, a narrowed portion 4a, and a bent portion 4b. The main body case 4 also has an opening 3 formed therein.

[0019] The top 4c closes one end of the main body case 4 in the Z direction. The opening 3 is located at the other end of the main body case 4 in the Z direction. The opening 3 is an opening that serves as a boundary between the inside and outside of the main body case 4. The body 4d extends from the periphery of the top 4c along the Z direction toward the opening 3 (toward the circuit board 2).

[0020] 2 is an enlarged cross-sectional view showing the vicinity of the drawn portion 4a. As shown in FIGS. 1 and 2, the drawn portion 4a is connected to the lower portion of the body portion 4d in the Z direction (the end portion of the body portion 4d on the circuit board 2 side). The drawn portion 4a has a shape that is narrowed in the radial direction of the body case 4, toward the inside of the body case 4, more than the body portion 4d and the bent portion 4b. The preferred position of the drawn portion 4a in the Z direction is approximately half the length from the body-side end face 6q (details will be described later) to the opening-side end face 6r (details will be described later) in the Z direction. The drawn portion 4a is formed in an annular shape so as to go around the inner surface of the body case 4.

[0021] More specifically, the inner surface of the drawn portion 4a protrudes further inward into the main body case 4 than the inner surface of the body portion 4d in a direction perpendicular to the Z direction (a direction parallel to the circuit board 2). The apex of the inner surface of the drawn portion 4a in the direction perpendicular to the Z direction (in other words, the part of the inner surface of the drawn portion 4a that is located furthest inside the main body case) is defined as apex P1. The inner diameter d1 of the main body case 4 at apex P1 is smaller than the inner diameter d2 of the main body case 4 at the body portion 4d.

[0022] The bent portion 4b is connected to the lower portion of the drawn portion 4a in the Z direction (the end portion of the drawn portion 4a on the circuit board 2 side). As the bent portion 4b approaches the circuit board 2 side along the Z direction from the lower portion of the drawn portion 4a, it bends in the Y direction toward the inside of the main body case 4. The tip of the bent portion 4b forms the opening edge of the opening 3.

[0023] The lower end 4e of the bent portion 4b (the portion of the main body case 4 located at the lowest position in the Z direction) faces closely to the surface of the seat plate 1a in the Z direction. Here, "facing closely" is understood to mean that the lower end 4e and the seat plate 1a may be in contact with each other, or may face each other in the Z direction with a small gap therebetween.

[0024] The capacitor element 5 is housed inside the main body case 4. The capacitor element 5 is located at a position overlapping the body portion 4d in the Z direction. The capacitor element 5 holds an electrolyte.

[0025] Fig. 3 is a perspective view showing the configuration of capacitor element 5. As shown in Fig. 3, capacitor element 5 has separator 10, anode foil 11, and cathode foil 12. Capacitor element 5 contains at least one of an electrolytic solution or a solid electrolyte.

[0026] Separator 10 is placed on anode foil 11. Cathode foil 12 faces anode foil 11 with separator 10 interposed therebetween. Separator 10, anode foil 11, and cathode foil 12 are wound and housed inside body portion 4d (see FIG. 1). The width of separator 10 in the Z direction is greater than the widths of anode foil 11 and cathode foil 12.

[0027] The sealing material 6 is an insulating elastic body and is made of, for example, butyl rubber, ethylene propylene rubber, or the like.

[0028] The sealing material 6 is a plate-like body that has a circular shape when viewed from above (see FIG. 5, which will be described later). As shown in FIGS. 1 and 2, the sealing material 6 is housed in the main body case 4. The sealing material 6 is located so as to overlap the narrowed portion 4a in the Z direction. The sealing material 6 is located between the capacitor element 5 and the opening 3 in the Z direction.

[0029] The sealing material 6 is inserted into the main case 4. The outer peripheral surface of the sealing material 6 abuts against the inner peripheral surface of the main case 4 (more specifically, the inner surface of the narrowed portion 4a). In this way, the sealing material 6 seals the opening 3. The detailed configuration of the sealing material 6 is as follows.

[0030] The sealing material 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 holding portions 6c and 6d.

[0031] The body-side end face 6q is the end face of the sealing material 6 in the Z direction on the capacitor element 5 side. The opening-side end face 6r is the end face of the sealing material 6 in the Z direction on the opening 3 side.

[0032] The first through hole 6a and the second through hole 6b penetrate the sealing material 6 in the thickness direction (=Z direction) from the body-side end face 6q to the opening-side end face 6r. The first through hole 6a and the second through hole 6b are aligned on a straight line L1 parallel to the circuit board 2 (see FIG. 5, which will be described later).

[0033] The direction in which the first through holes 6a and the second through holes 6b are aligned will be referred to as the "X direction" (first direction) below. The direction perpendicular to the X and Z directions will be referred to as the "Y direction" (second direction) below. In each drawing, the direction indicated by the arrow XX' is shown as the X direction, and the direction indicated by the arrow YY' is shown as the Y direction.

[0034] The retaining portions 6c and 6d are located at both ends of the sealing material 6 in the X direction. The retaining portions 6c and 6d protrude downward in the Z direction (in the direction opposite to the main body side end surface 6q) from the edge of the opening side end surface 6r. The retaining portions 6c and 6d face each other in the X direction. It is preferable that the retaining portions 6c and 6d are formed so as to be connected to each other in the Y direction, as this improves sliding properties at the contact portion between the sealing material 6 and the main body case 4.

[0035] The outer surfaces of the holding portions 6c and 6d in the X direction are tapered so that as they approach the circuit board 2 in the Z direction, they move away from the inner surface of the main body case 4 in the X direction (in other words, they move closer to the center O, which will be described later).

[0036] A gap a1 is provided in the Z direction between the holding portions 6c, 6d (more specifically, the tapered portions described above) and the inner surface of the bent portion 4b. The gap a1 gradually increases from the capacitor element 5 side of the holding portions 6c, 6d toward the opening 3. 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.

[0037] 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 penetrate the base plate 1a.

[0038] One end of each of first lead terminal 7a and second lead terminal 7b is located inside main body case 4 (more specifically, inside trunk portion 4d). One end of first lead terminal 7a is connected to anode foil 11. One end of second lead terminal 7b is connected to cathode foil 12.

[0039] The other ends of the first lead terminal 7a and the second lead terminal 7b are drawn out to the outside of the main body case 4 (outside the opening 3 of the main body case 4). The detailed configuration of the first lead terminal 7a is as follows.

[0040] 2, the first lead terminal 7a has a first member 21 and a second member 22. The first member 21 is made of, for example, aluminum. The second member 22 is made of, for example, CP wire, which is an iron wire with a copper layer provided on the outer surface thereof.

[0041] The first member 21 has a first round bar portion 15a, a first rib portion 15b, a first welded 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 welded portion 15c are formed by utilizing the shape of the round bar (e.g., a cylindrical aluminum material) that forms the first member 21.

[0042] The first round bar portion 15a is press-fitted (inserted with interference) into the first through-hole 6a. The first round bar portion 15a is positioned so as to overlap the drawn portion 4a in the Z direction. The diameter of the first round bar portion 15a (diameter d3) is larger than the width of the first welded portion 15c (the length in the direction parallel to the plane perpendicular to the arrow ZZ' shown in FIG. 1).

[0043] The first rib portion 15b is formed at an end of the first round bar portion 15a closer to the flat plate portion 25. The second member 22 is drawn out to the outside of the main body case 4.

[0044] The first welded portion 15c is located below the first round bar portion 15a in the Z direction (toward the circuit board 2) and is the welded portion between the first member 21 and the second member 22. The first welded portion 15c is formed so that its width increases from the lower end toward the top in the Z direction. The diameter d4 of the first lead terminal 7a at the other end side (the end side drawn out to the outside of the main body case 4) of the first welded portion 15c is smaller than the diameter d3 of the first round bar portion 15a.

[0045] The flat plate portion 25 is formed in a long, thin plate shape, and the width of the flat plate portion 25 is constant from the first rib portion 15b to the tip. The flat plate portion 25 is formed by pressing one end of the round bar that forms the first member 21 and cutting off the unnecessary portion. The first rib portion 15b is also formed at the same time during the pressing process.

[0046] The second member 22 is a tin-plated CP wire. The second member 22 is inserted into a hole (not shown) formed in the first welding portion 15c of the first member 21 and welded thereto. This mechanically and electrically fixes the first member 21 and the second member 22 together. The second member 22 has a first bent portion 16 (first fixed portion) located at the end opposite the first member 21.

[0047] 1, the first bent portion 16 extends downward in the Z direction from the lower end of the first welded portion 15c and is bent toward the outside of the electrolytic capacitor 1 along the circuit board 2. The portion of the first lead terminal 7a on the other end side from the first bent portion 16 is soldered to the circuit board 2.

[0048] The detailed configuration of the second lead terminal 7b is as follows. As shown in Fig. 2, the second lead terminal 7b has a third member 23 and a fourth member 24. The third member 23 is made of, for example, aluminum. The fourth member 24 is made of, for example, CP wire, which is an iron wire with a copper layer provided on the outer surface thereof.

[0049] The third member 23 has a second round bar portion 17a, a rib portion 17b, a second welded 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 welded portion 17c are formed by utilizing the shape of the round bar (e.g., a cylindrical aluminum material) that forms the third member 23.

[0050] The second round bar portion 17a is press-fitted (inserted with interference) into the second through-hole 6b. The second round bar portion 17a is positioned so as to overlap the drawn portion 4a in the Z direction. The diameter of the second round bar portion 17a (diameter d5 of the second round bar portion 17a) is larger than the width of the second welded portion 17c.

[0051] The second rib portion 17b is formed at an end of the second round bar portion 17a closer to the flat plate portion 26. The fourth member 24 is drawn out to the outside of the main body case 4.

[0052] The second welded portion 17c is located below the second round bar portion 17a in the Z direction (toward the circuit board 2), and is the welded portion between the third member 23 and the fourth member 24. The second welded portion 17c is formed so that its width increases upward from its lower end in the Z direction (the boundary with the fourth member 24). The diameter d4 of the second lead terminal 7b at the other end side (the end side drawn out to the outside of the main body case 4) of the second welded portion 17c is smaller than the diameter d5 of the second round bar portion 17a.

[0053] The flat plate portion 26 is formed in a long, thin plate shape, and the width of the flat plate portion 26 is constant from the second rib portion 17b to the tip. The flat plate portion 26 is formed by pressing one end of the round bar that forms the third member 23 and cutting off the unnecessary portion. The second rib portion 17b is also formed at the same time during the pressing process.

[0054] The fourth member 24 is a tin-plated CP wire. The fourth member 24 is inserted into a hole (not shown) provided in the second welding portion 17c of the third member 23 and welded thereto. This mechanically and electrically fixes the third member 23 and the fourth member 24. The fourth member 24 has a second bent portion 18 (second fixing portion) located at the end opposite the third member 23. The diameter d6 of the fourth member 24 is smaller than the diameter d5 of the second round bar portion 17a.

[0055] 1, the second bent portion 18 extends downward in the Z direction from the lower end of the second welded portion 17c and is bent toward the outside of the electrolytic capacitor 1 along the circuit board 2. The portion of the second lead terminal 7b on the other end side from the second bent portion 18 is soldered to the circuit board 2.

[0056] The external pressure deformation suppression plate 8 is made of a synthetic resin plate mixed with a reinforcing material (glass fiber, cellulose fiber, ceramic, etc.) The external pressure deformation suppression plate 8 is made of, for example, Bakelite (registered trademark).

[0057] The external pressure deformation suppression plate 8 is an elliptical plate-like body having a minor axis d9 and a major axis d10 when viewed in a plan view along the Z direction (see Figures 5 and 6, which will be described later). 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.

[0058] As shown in Figures 1 and 2, the surface of the external pressure deformation suppression plate 8 on the sealing material 6 side is in slidable contact with the opening side end surface 6r. The surface of the external pressure deformation suppression plate 8 opposite the sealing material 6 faces the tip of the bent portion 4b in the Z direction. The external pressure deformation suppression plate 8 and the tip of the bent portion 4b face each other in contact with each other or face each other with a small gap in between.

[0059] The external pressure deformation suppression plate 8 has a third through hole 8c, a fourth through hole 8d, a pair of held portions 8a, and a pair of outer peripheral extension portions 8b (see FIG. 5, which will be described later).

[0060] The third through hole 8c and the fourth through hole 8d are holes that penetrate the external pressure deformation suppression plate 8 in the thickness direction (=Z direction). The third through hole 8c and the fourth through hole 8d are aligned along the X direction. The center of the third through hole 8c is located at the same position as the center of the first through hole 6a in the X and Y directions (see FIG. 5, which will be described later). The center of the fourth through hole 8d is located at the same position as the center of the second through hole 6b in the X and Y directions (see FIG. 5, which will be described later).

[0061] 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, a gap a3 is formed between the first lead terminal 7a and the inner circumferential surface of the third through hole 8c.

[0062] 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, a gap a4 is formed between the second lead terminal 7b and the inner surface of the fourth through hole 8d.

[0063] The inner diameter d7 of the third through hole 8c is smaller than the diameter d3 of the first round bar portion 15a described above. In the Z direction, an edge 8m of the third through hole 8c located on the sealing material 6 side is located lower than the first round bar portion 15a. The edge 8m and the first welded 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 described above. In the Z direction, an edge 8n of the fourth through hole 8d located on the sealing material 6 side is located lower than the second round bar portion 17a. The edge 8n and the second welded portion 17c face each other in the Z direction.

[0064] The pair of held portions 8a are located on both sides in the X direction of the external pressure deformation suppression plate 8 (portions overlapping the outer periphery of the external pressure deformation suppression plate 8). The held portions 8a are located more inward in the X direction than the holding portions 6c, 6d. The held portions 8a may be formed along the entire outer periphery of the external pressure deformation suppression plate 8.

[0065] The outer peripheral surfaces of the pair of held portions 8a (surfaces of the held portions 8a parallel to the Z direction) abut against the inner peripheral surfaces of the holding portions 6c, 6d (surfaces of the holding portions 6c, 6d perpendicular to the opening-side end face 6r). The outer peripheral surfaces of the pair of held portions 8a are rougher than the surface of the external pressure deformation suppression plate 8 on the capacitor element 5 side. As a result, the sealing material 6 enters the holes and valleys in the rough surface portions, and the outer peripheral surface of each held portion 8a and the inner peripheral surfaces of the holding portions 6c, 6d are bonded together by an anchor effect.

[0066] A pressing force according to the elastic modulus of the sealing material 6 is applied by the holding portions 6c, 6d toward the external pressure deformation suppression plate 8 (more specifically, the held portion 8a) in the X direction. As a result, the external pressure deformation suppression plate 8 is sandwiched between the holding portions 6c, 6d. In this way, the external pressure deformation suppression plate 8 is held by the sealing material 6 by being sandwiched and adhered to the holding portions 6c, 6d.

[0067] The bonding points between the pair of held portions 8a and the holding portions 6c, 6d are located outside the opening 3 in the X direction. The detailed configuration of the pair of outer peripheral extension portions 8b will be described later.

[0068] If the internal pressure of the electrolytic capacitor 1 increases due to reflow when the capacitor is attached to the circuit board 2, and the sealing material 6 is pressed toward the circuit board 2 in the Z direction, the sealing material 6 is restricted from moving toward the circuit board 2 in the Z direction due to the contact between the external pressure deformation suppression plate 8 and the tip of the bent portion 4b. Even if the sealing material 6 is deforming or moving, the sealing material 6 can slide against the abutting main body case, first round bar portion 15a, second round bar portion 17a, and element-side end surface 6r of the external pressure deformation suppression plate 8, and therefore a decrease in the sealing effect of the sealing material 6 is suppressed.

[0069] After reflow, the portion of the first lead terminal 7a from the first bent portion 16 to the other end is soldered and fixed to the circuit board 2. Also, the portion of the second lead terminal 7b from the second bent portion 18 to the other end is soldered and fixed to the circuit board 2.

[0070] FIG. 4 is a diagram showing the state in which the periphery of electrolytic capacitor 1 has been molded. As shown in FIG. 4, the periphery of the above-described electrolytic capacitor 1 can be molded together with circuit board 2 in mold resin 9. Molding the periphery of electrolytic capacitor 1 can improve waterproofness, moisture resistance, oil resistance, chemical resistance, dust resistance, and vibration resistance. As shown in FIG. 4, molding with mold resin 9 can be performed by molding the electrolytic capacitor 1 side (front side) of electrolytic capacitor 1 and circuit board 2 with mold resin 9, or the back side of circuit board 2 can also be molded together (not shown).

[0071] When molding the periphery of electrolytic capacitor 1, a mold is prepared that covers the area to be molded, and molding resin 9 is injected into this mold. At this time, the injection pressure of molding resin 9 (indicated by the white arrow in Figure 4) acts on electrolytic capacitor 1.

[0072] Specifically, when the molding resin is injected, a pressing force acts on the top 4c in the Z direction toward the inside of the main case 4, a pressing force acts on the side of the main case 4 (body 4d, narrowed portion 4a, and bent portion 4b) in the X direction toward the capacitor element 5 (inward of the main case 4), and a pressing force acts on the external pressure deformation suppression plate 8 and the sealing material 6 in the Z direction toward the capacitor element 5 (inward of the main case 4).

[0073] As described above, when the top 4c is pressed inward of the main body case 4 along the Z direction (when the top 4c is pressed toward the capacitor element 5), the lower end 4e of the bent portion 4b faces closely to the surface of the seat plate 1a in the Z direction, thereby restricting movement of the main body case and preventing adverse effects on the capacitor element.

[0074] As described above, when the external pressure deformation suppression plate 8 is pressed toward the capacitor element (the side opposite the circuit board 2) along the Z direction, the edge 8m of the third through hole 8c of the external pressure deformation suppression plate 8 and the edge 8n of the fourth through hole 8d abut against the first welding portion 15c of the first lead terminal 7a and the second welding portion 17c of the second lead terminal, which respectively have fixing portions fixed to the circuit board 2, thereby restricting movement.

[0075] In this way, even if the external pressure deformation suppression plate 8 and the sealing material 6 are pressed in the Z direction by injection of a mold or the like, the restriction on the movement of the external pressure deformation suppression plate 8 also restricts the movement of the sealing material 6 in the Z direction toward the capacitor element. Therefore, the force of the sealing material 6 pressing against the capacitor element 5 is less likely to act, and adverse effects on the capacitor element 5 can be suppressed.

[0076] As described above, the opening-side end surface 6r and the end surface of the external pressure deformation suppression plate 8 facing the sealing material 6 are slidable. Therefore, when the electrolytic capacitor 1 expands or contracts depending on the environment in which the electrolytic capacitor 1 is placed, the sealing material 6 is likely to deform in response to this expansion or contraction. In other words, when the sealing material 6 deforms, the external pressure deformation suppression plate 8 is less likely to hinder the deformation of the sealing material 6. Therefore, even if the electrolytic capacitor 1 expands or contracts, the sealing effect of the sealing material 6 can be prevented from decreasing.

[0077] As described above, a gap a3 exists between the first lead terminal 7a and the inner circumferential surface of the third through hole 8c, and a gap a4 exists between the second lead terminal 7b and the inner circumferential surface of the fourth through hole 8d. Therefore, even if the sealing material 6 moves slightly in the Z direction, friction between the first lead terminal 7a and the second lead terminal 7b and the sealing material 6 is small. This reduces damage to the first lead terminal 7a and the second lead terminal 7b. Furthermore, this reduces the peeling of the tin plating applied to the surface of the first lead terminal 7a on the other end side of the first welded portion 15c and the surface of the second lead terminal 7b on the other end side of the second welded portion 17c due to friction with the sealing material 6.

[0078] As described above, a gap a1 is formed between the holding portions 6c, 6d and the inner surface of the bent portion 4b. The gap a1 gradually increases from the capacitor element 5 side of the holding portions 6c, 6d toward the opening 3. Therefore, the pressure acting on the holding portion 6c when the molding resin 9 is injected tends to be parallel to the external pressure deformation suppression plate 8 (along the X direction). This allows the outer periphery of the external pressure deformation suppression plate 8 to be firmly held by the holding portion 6c. Even if the sealing material 6 deforms or moves toward the capacitor element 5 (inside the main case 4) due to the pressure of the molding resin 9, the external pressure deformation suppression plate 8 restricts the movement of the sealing material 6. As a result, the distance between the main body-side end surface 6q of the sealing material 6 and the capacitor element 5 is prevented from becoming closer, thereby preventing adverse effects on the capacitor element 5.

[0079] As described above, the width of separator 10 in the Z direction is greater than the width of anode foil 11 and the width of cathode foil 12. Therefore, even if sealing material 6 presses capacitor element 5, separator 10 acts as a buffer, making it difficult for force to be applied to anode foil 11 and cathode foil 12. This prevents damage to the width of anode foil 11 and cathode foil 12.

[0080] <Regarding the Preferred Configuration of the Sealing Material 6 and the External Pressure Deformation Suppression Plate 8> Next, preferred configurations of the sealing material 6 and the external pressure deformation suppression plate 8 will be described.

[0081] FIG. 5 is a plan view of the sealing material 6 and the external pressure deformation suppression plate 8 viewed from the opening-side end face 6r along the Z direction. FIG. 6 is a perspective view of the sealing material 6 and the external pressure deformation suppression plate 8. As shown in FIGS. 5 and 6, in addition to the configuration described above, the sealing material 6 has cutouts 6t and 6u formed therein. The cutouts 6t and 6u are cutouts formed along the periphery of the sealing material 6 and comprise the retaining portion 6c, the opening-side end face 6r, and the retaining portion 6d. The cutouts 6t and 6u are shaped like cutouts formed between the retaining portion 6c and the retaining portion 6d along the periphery of the sealing material 6. The external pressure deformation suppression plate 8 is inserted into the cutouts 6t and 6u.

[0082] The deflection temperature under load of the external pressure deformation suppression plate 8 (measured in accordance with ASTM [American Society for Testing and Materials] Standard "D648" Method A (1.82 MPa)) is 140°C or higher and 240°C or lower. The deflection temperature under load is adjusted by adjusting the synthetic resin plate, the reinforcing material mixed in, and the amount of reinforcing material mixed in. By using such an external pressure deformation suppression plate 8, even if the ambient temperature of the electrolytic capacitor 1 rises (220°C to 260°C) during reflow, causing an increase in pressure inside the electrolytic capacitor 1 (i.e., inside the main case 4) and stress accompanied by deformation of the encapsulant 6 is applied to the external pressure deformation suppression plate 8, the rigidity of the external pressure deformation suppression plate 8 decreases, causing the central portion of the external pressure deformation suppression plate 8 (i.e., the area including the center O and surrounding the center O) to elastically deform and bend toward the circuit board 2. That is, when the sealing material 6 deforms, the external pressure deformation suppression plate 8 is less likely to hinder the deformation of the sealing material 6, thereby suppressing cracking, breakage, and destruction of the external pressure deformation suppression plate 8. Furthermore, at a mold temperature during molding (for example, 120°C to 180°C), the rigidity of the external pressure deformation suppression plate 8 is maintained high, suppressing deformation of the external pressure deformation suppression plate 8 against the resin injection pressure, suppressing deformation of the sealing material 6, and preventing damage to the capacitor element 5. Furthermore, because the central portion of the external pressure deformation suppression plate 8 is curved so as to protrude toward the circuit board 2 due to plastic deformation during reflow, the strength against the resin injection pressure is increased compared to when it is flat, making it possible to more effectively suppress damage to the capacitor element 5.

[0083] Furthermore, the thickness of the external pressure deformation suppression plate 8 is preferably 0.5 mm to 1.5 mm. If it is thinner than 0.5 mm, the rigidity against the injection pressure of the molding resin will be weak, and if it is thicker than 1.5 mm, even if a strong internal pressure rise occurs during reflow, the elastic deformation of the external pressure deformation suppression plate will be small, and there is a risk that the main body case 4 will be deformed.

[0084] The pair of held portions 8a are located on a straight line L1 drawn to pass through the center of the first through hole 6a and the center of the second through hole 6b. That is, the pair of held portions 8a, the first through hole 6a, and the second through hole 6b are aligned on the straight line L1. The center 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 as follows.

[0085] The end of the held portion 8a in the X direction (the outermost portion in the X direction of the external pressure deformation suppression plate 8) is defined as vertex P2. Vertex P2 is located on line L1. As shown in FIG. 2, vertex P2 is located further inside the main case 4 than vertex P1 in the X direction. Vertex P2 is also located further outside than the edge of the opening 3 in the X direction. The aforementioned minor axis d9 can be said to be the distance in the X direction between vertices P2.

[0086] 5 and 6, in addition to the above-described configuration, the external pressure deformation suppression plate 8 has an outer peripheral extension 8b. The outer peripheral extension 8b is connected to the held portions 8a along the outer periphery of the sealing material 6. The outer peripheral extension 8b is located between the pair of held portions 8a in the X direction.

[0087] Here, a straight line L2 is drawn so as to be perpendicular to the straight line L1 and pass through the center O in the X and Y directions of the external pressure deformation suppression plate 8. The pair of outer peripheral extensions 8b are located on the straight line L2.

[0088] In the Y direction, the outer peripheral extension 8b protrudes outward from the apex P1 of the drawn portion 4a. The outer peripheral extension 8b will be described in more detail below.

[0089] Fig. 7 is a cross-sectional view of electrolytic capacitor 1 taken along line L2 shown in Fig. 6. As shown in Figs. 5 to 7, line L3 is positioned so as to overlap with the Y-direction end of peripheral extension 8b (the outermost portion of external pressure deformation suppression plate 8 in the Y direction) in the X direction. More specifically, the Y-direction end of peripheral extension 8b is preferably positioned closer to the center of peripheral extension 8b in the X direction and closer to line L2.

[0090] As described above, the end of the outer peripheral extension 8b is located further outward from the apex P1 of the main case 4 in the Y direction. 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 narrowed portion 4a of the main case 4 supports the outer peripheral extension 8b. This makes it possible to further suppress the external pressure deformation suppression plate 8 (and therefore the sealing material 6) from being pressed toward the capacitor element 5 (inside the main case 4) along the Z direction.

[0091] As described above, the holding portion 6c, the held portion 8a, the third through hole 8c, the fourth through hole 8d, the held portion 8a, and the holding portion 6d are arranged in this order on the straight line L1. In other words, the second member 22 and the fourth member 24 are positioned between one held portion 8a in the X direction.

[0092] Furthermore, as described above, line L1 and line L2 are perpendicular to each other. In other words, the first through hole 6a, the second through hole 6b, the held portion 8a, and the holding portions 6c and 6d, which are aligned on line L1, are perpendicular to the outer periphery extension 8b, which is aligned on line L2. Therefore, the sealing material 6 is less likely to deform in the X direction due to contact between the holding portions 6c and 6d and the held portion 8a, and is less likely to deform in the Y direction due to contact between the outer periphery extension 8b and the opening-side end face 6r.

[0093] <Modification> The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit of the present invention. For example, although the preferred configuration of the external pressure deformation suppression plate 8 is an ellipse when viewed from above, the present invention is not limited to this. Specifically, the shape may be other than an ellipse (e.g., a polygon such as a hexagon or a diamond-shaped rectangle) in which the distance from the center O to the tip of the outer peripheral extension 8b in the Y direction is longer than the distance from the center O to the tip of the held portion 8a in the X direction, or may be a circle without the outer peripheral extension 8b.

[0094] <Additional Notes> The electrolytic capacitor (1) includes a cylindrical main case (4) with one end closed and an opening (3) formed at the other end, a capacitor element (5) housed in the main case (4), a sealant (6) arranged inside the main case (4) and having a first through hole (6a) and a second through hole (6b) aligned in a first direction (XX') to seal the opening (3), and a sealant (6) arranged in slidable contact with an opening-side end face (6r) that is the end face of the sealant (6) on the opening (3) side, and having a first through hole (6a) and a second through hole (6b) aligned in the first direction (XX') and a second direction (YY') perpendicular to the first direction (XX'). The external pressure deformation suppression plate (8) has a third through hole (8c) formed therein that overlaps with the hole (6a) and a fourth through hole (8d) formed therein that overlaps with the second through hole (6b) in the first direction (XX') and the second direction (YY'), a first lead terminal (7a) connected to the capacitor element (5) inside the main case (4) and drawn out to the outside of the main case (4) through the first through hole (6a) and the third through hole (8c), and a second lead terminal (7b) connected to the capacitor element (5) inside the main case (4) and drawn out to the outside of the main case (4) through the second through hole (6b) and the fourth through hole (8d). and a base plate (1a) to which the first lead terminal (7a) and the second lead terminal (7b) are soldered, the base plate (1a) being adjacent to and facing the end (4e) of the opening (3) side of the main case (4) in a third direction (ZZ') perpendicular to the first direction (XX') and the second direction (YY'), the first lead terminal (7a) having a first round bar portion (15a) located inside the first through hole (6a) and having an outer diameter (d3) larger than the inner diameter (d7) of the third through hole (8c), and a first fixing portion (16) located outside the main case (4) and soldered to the base plate (1a), the first lead terminal (7a) having a first round bar portion (15a) located inside the first through hole (6a) and having an outer diameter (d3) larger than the inner diameter (d7) of the third through hole (8c), and a first fixing portion (16) located outside the main case (4) and soldered to the base plate (1a), the fourth through hole (8d) has a second round rod portion (17a) located inside the second through hole (6b) and having an outer diameter (d5) larger than the inner diameter (d8) of the fourth through hole (8d), and a second fixing portion (18) located outside the main case (4) and soldered to the seat plate (1a); the main case (4) has a body portion (4d) that houses the electrolytic capacitor (1) therein, and a drawn portion (4a) that extends from the body portion (4d) to the opening (3) and has an inner diameter (d1) smaller than the inner diameter (d2) of the body portion (4d); the sealing material (6) is located at a position that overlaps with the drawn portion (4a) in the third direction (ZZ');When the sealing material (6) is pressed toward the capacitor element (5) in the third direction (ZZ'), the edge (8m) of the third through hole (8c) abuts against the first welded portion (15c) and the edge (8n) of the fourth through hole (8d) abuts against the second welded portion (17c), thereby restricting movement toward the capacitor element (5), and gaps (a3, a4) are present 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 configuration).

[0095] In the electrolytic capacitor (1) according to the first configuration, the capacitor element (5) has an anode foil (11), a separator (10) superimposed on the anode foil (11), and a cathode foil (12) facing the anode foil (11) with the separator (10) interposed therebetween, and the anode foil (11), separator (10), and cathode foil (12) are wound around the capacitor element (5). One end of the first lead terminal (7a) is connected to the anode foil (11), and the other end is drawn out to the outside of the main case (4). One end of the second lead terminal (7b) is connected to the cathode foil (12) and the other end is drawn out to the outside of the main case (4), the width of the separator (10) in the third direction (ZZ') is greater than the widths of the cathode foil (12) and the anode foil (11) in the third direction (ZZ'), and the cathode foil (12) and the anode foil (11) are arranged more inward than both end portions of the separator (10) in the third direction (ZZ') (second configuration).

[0096] In the electrolytic capacitor (1) according to the first configuration, the main body case (4) has a bent portion (4b) that extends from the narrowed portion (4a) toward the inside of the main body case (4) to the opening (3) while bending, and the end portion in the third direction (ZZ') is close to or abuts the opening side end face (6r) so as to face the third direction (ZZ') (third configuration).

[0097] In the electrolytic capacitor (1) according to the first configuration, the sealing portion has a pair of holding portions (6c, 6d) that protrude in a third direction (ZZ') from the peripheral edge of the opening-side end face (6r) toward the opening (3), and that are provided on both sides of the external pressure deformation suppression plate (8) in the first direction (XX'), and the external pressure deformation suppression plate (8) has a pair of held portions (8a) that face and abut against each of the holding portions (6c, 6d) in the first direction (XX'), and a pair of held portions (8a) that are connected to each of the held portions (8a) and are provided between each of the holding portions (6c, 6d) in the first direction (XX'). and a pair of outer peripheral extension portions (8b) positioned at opposite ends of the external pressure deformation suppression plate (8) in the second direction (YY'), and when the external pressure deformation suppression plate (8) is viewed in a plane along the third direction (ZZ'), a first distance from a center portion (O) of the external pressure deformation suppression plate (8) in the first direction (XX') and the second direction (YY') to the end of the held portion (8a) in the first direction (XX') is longer than a second distance from the center portion (O) to the end of the outer peripheral extension portion (8b) in the second direction (YY') (fourth configuration).

[0098] In the electrolytic capacitor (1) according to the fourth configuration, each holding portion (6c, 6d) is arranged on a first straight line (L1) drawn through the center of the first through hole (6a) and the center of the second through hole (6b), one on each side of the first through hole (6a) and the second through hole (6b), and a second straight line (L2) drawn through each of the outer peripheral extension portions (8b) is perpendicular to the first straight line (L1) (fifth configuration).

[0099] In the electrolytic capacitor (1) according to the fifth configuration, the intersection of the first straight line (L1) and the second straight line (L2) is located at a position that overlaps with the center (O) (sixth configuration).

[0100] In the electrolytic capacitor (1) according to the sixth configuration, the second straight line (L2) passes over the end of each outer peripheral extension portion (8b) in the second direction (YY') (seventh configuration).

[0101] In the electrolytic capacitor (1) of the fourth configuration, the sealing material (6) has a circular shape when viewed in a plane along the third direction (ZZ'), the external pressure deformation suppression plate (8) has an elliptical cylindrical shape when viewed in a plane along the third direction (ZZ'), and has a minor axis (d9) parallel to the first direction (XX') and a major axis (d10) parallel to the second direction (YY'), and each held portion (8a) is located at each end of the external pressure deformation suppression plate (8) along the minor axis (d9) (eighth configuration).

[0102] In the electrolytic capacitor (1) according to the eighth configuration, each outer peripheral extension (8b) is located at each end of the external pressure deformation suppression plate (8) along the major axis (d10) (ninth configuration).

[0103] In the electrolytic capacitor (1) according to any one of the first to ninth configurations, the external pressure deformation suppression plate (8) has a load-strain temperature measured in accordance with the ASTM D648 standard of 140°C or higher and 240°C or lower (tenth configuration). [Explanation of symbols]

[0104] 1 electrolytic capacitor 1a Seat board 2 Circuit Boards 3 Opening 4 Main unit case 4a Constriction section 4b Bend part 4c top 4d Torso 4e Bottom end 5 Capacitor elements 6. Encapsulating material 6a 1st through hole 6b 2nd through hole 6c, 6d holding part 6q Body side end surface 6r Opening side end surface 6t, 6u notch 7a First lead terminal 7b Second lead terminal 8. External pressure deformation suppression plate 8a Holding part 8b Perimeter extension 8c 3rd through hole 8d 4th through hole 8m, 8n edges 9 Molding resin 10 Separator 11 Anode foil 12 Cathode foil 15a First round bar section 15b First rib section 15c First weld 16 1st bending part (1st fixed part) 17a Second round bar section 17b Second rib section 17c Second weld 18 Second bent part (second fixed part) 21 First member 22 Second member 23 Third member 24 Fourth member 25, 26 Flat plate part L1 straight line (first straight line) L2 straight line (second straight line) O center P1 vertex P2 Vertex a1 Gap a3 gap a4 gap d1 Inner diameter d2 inner diameter d3 diameter d4 diameter d5 diameter d6 diameter d7 Inner diameter d8 inner diameter d9 short axis d10 long axis

Claims

1. a cylindrical main body case having one end closed and the other end opened; a capacitor element housed in the main body case; a sealant disposed inside the main body case and sealing the opening, the sealant having a first through hole and a second through hole aligned in a first direction; an external pressure deformation suppression plate that is disposed in slidable contact with the opening-side end surface that is the end surface on the opening side of the sealing material, the external pressure deformation suppression plate having a third through hole formed therein that overlaps with the first through hole in the first direction and a second direction perpendicular to the first direction, and a fourth through hole formed therein that overlaps with the second through hole in the first direction and the second direction; a first lead terminal connected to the capacitor element within the main body case and drawn out to the outside of the main body case through the first through hole and the third through hole; a second lead terminal connected to the capacitor element within the main body case and drawn out to the outside of the main body case through the second through hole and the fourth through hole; a seat plate that faces closely to an end of the main body case on the opening side in a third direction perpendicular to the first direction and the second direction; Equipped with The first lead terminal is a first round bar portion located inside the first through hole and having an outer diameter larger than an inner diameter of the third through hole; a first fixing portion located outside the main body case and soldered to a circuit board; and The second lead terminal is a second round bar portion located inside the second through hole and having an outer diameter larger than an inner diameter of the fourth through hole; a second fixing portion located outside the main body case and soldered to a circuit board; and The main body case includes: a body portion that houses the electrolytic capacitor; a throttle portion extending from the body portion to the opening and having an inner diameter smaller than an inner diameter of the body portion; and the sealing material is located at a position overlapping the narrowed portion in the third direction, when the sealing material is pressed toward the capacitor element along the third direction, an edge portion of the third through hole abuts against the first welded portion and an edge portion of the fourth through hole abuts against the second welded portion, thereby restricting movement toward the capacitor element, An electrolytic capacitor in which 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 capacitor element is an anode foil; a separator overlaid on the anode foil; a cathode foil facing the anode foil with the separator interposed therebetween; the anode foil, the separator, and the cathode foil are wound together, one end of the first lead terminal is connected to the anode foil and the other end is drawn out to the outside of the main body case, one end of the second lead terminal is connected to the cathode foil and the other end is drawn out to the outside of the main body case, a width of the separator in the third direction is greater than a width of each of the cathode foil and the anode foil in the third direction; 2. The electrolytic capacitor according to claim 1, wherein the cathode foil and the anode foil are disposed inside both end portions of the separator in the third direction.

3. 2. The electrolytic capacitor according to claim 1, wherein the main body case has a bent portion that extends from the narrowed portion toward the inside of the main body case to the opening, and whose end in the third direction is close to or abuts the opening side end face so as to face the third direction.

4. the sealing portion has a pair of holding portions that protrude in the third direction from a peripheral edge portion of the opening-side end face toward the opening side, the holding portions being provided one on each side of the external pressure deformation suppression plate in the first direction, The external pressure deformation suppression plate is a pair of held portions that face and come into contact with the holding portions in the first direction; a pair of outer peripheral extension portions respectively connected to the held portions, respectively positioned between the holding portions in the first direction, and respectively positioned at both ends of the external pressure deformation suppression plate in the second direction; and 2. The electrolytic capacitor according to claim 1, wherein, when the external pressure deformation suppression plate is viewed in a plane along the third direction, a first distance from a center of the external pressure deformation suppression plate in the first direction and the second direction to an end of the held portion in the first direction is longer than a second distance from the center to an end of the outer peripheral extension portion in the second direction.

5. the holding portions are arranged on a first line drawn through a center of the first through hole and a center of the second through hole, one on each side of the first through hole and the second through hole, 5. The electrolytic capacitor according to claim 4, wherein a second line drawn so as to pass through each of the outer peripheral extensions is perpendicular to the first line.

6. The electrolytic capacitor according to claim 5 , wherein the intersection of the first line and the second line is located at a position that overlaps with the center portion.

7. The electrolytic capacitor according to claim 6 , wherein the second straight line passes over an end of each of the outer peripheral extensions in the second direction.

8. the sealing material has a circular shape when viewed in a plan view along the third direction, the external pressure deformation suppression plate has an elliptical cylindrical shape when viewed in a plan view in the third direction, and has a minor axis parallel to the first direction and a major axis parallel to the second direction, 5. The electrolytic capacitor according to claim 4, wherein the held portions are located at both ends of the external pressure deformation suppression plate along the minor axis.

9. 9. The electrolytic capacitor according to claim 8, wherein each of the outer peripheral extensions is located at both ends of the external pressure deformation suppression plate along the major axis.

10. 10. The electrolytic capacitor according to claim 1, wherein the external pressure deformation suppression plate has a load-strain temperature of 140°C or higher and 240°C or lower, as measured in accordance with ASTM D648 standard.

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