Multilayer solid electrolytic capacitor and method for manufacturing same

Abstract

In the present invention, the occurrence of defects due to foreign matter, caused by mold fabrication or blasting, is prevented. A first terminal (20) of a multilayer solid electrolytic capacitor (1) is provided, on a first lateral surface (44F), with a first through-hole at least a portion of which is contained within an exterior resin body (40). In plan view from a direction orthogonal to a bottom surface (45F), the first through-hole is positioned only within the contour of the exterior resin body.

Description

Stacked solid electrolytic capacitor and method for manufacturing the same

[0001] The present invention relates to a stacked solid electrolytic capacitor and a method for manufacturing the same.

[0002] A stacked solid electrolytic capacitor is known which uses a capacitor element having a cathode formed therein, wherein a foil of a valve metal such as aluminum is used as an anode, and the capacitor element includes a dielectric oxide film formed to cover the valve metal and a solid electrolyte layer. The stacked solid electrolytic capacitor includes a stacked body obtained by stacking a plurality of such capacitor elements, an anode terminal connected to the anode of each capacitor element, a cathode terminal connected to the cathode of each solid capacitor element, and an exterior resin body.

[0003] A stacked solid electrolytic capacitor including an anode terminal or a cathode terminal provided with a through hole (hole portion) spanning between the inside and the outside of the exterior resin body has also been proposed. In the stacked solid electrolytic capacitor having such a configuration, the exterior resin body enters the inside of the through hole and the terminal is fixed to the exterior resin body, so that even if a force acts on the terminal, peeling from the exterior resin body is less likely to occur.

[0004] Japanese Patent Application Laid-Open No. 2024-142925

[0005] In such a stacked solid electrolytic capacitor, when the exterior resin body is formed by molding, burrs may be formed on the outside of the exterior resin body. Such burrs may become foreign matter and cause a problem of damaging jigs used in manufacturing or final products, and therefore are removed by blasting or the like.

[0006] In a stacked solid electrolytic capacitor including a terminal having a through hole spanning between the inside and the outside of the exterior resin body as described above, burrs may also be formed inside the external-side through hole. Since such burrs inside the external-side through hole adhere to the anode terminal or the like in the surrounding area, they are less likely to be removed by blasting compared to burrs in other portions. Increasing the blasting strength is conceivable as a means for reliably removing the burrs.

[0007] However, increasing the intensity of the blasting process can lead to problems such as damaging the anode terminal, cathode terminal, or outer resin body, or causing warping of the terminals, making subsequent processing difficult. In addition, blast particles can sometimes become clogged inside the through-holes, leading to problems such as detachment during post-blasting processes or weak adhesion, resulting in defects similar to burrs. One aspect of the present invention aims to realize a multilayer solid electrolytic capacitor that employs anode or cathode terminals with through-holes while preventing defects caused by foreign matter resulting from mold molding or blasting.

[0008] To solve the above problems, a laminated solid electrolytic capacitor according to one aspect of the present disclosure comprises a laminate in which a plurality of capacitor elements are stacked, an outer resin body having a box-shaped outer form and enclosing the laminate, and a first terminal located inside the outer resin body that is electrically connected to either the anode or cathode of the capacitor elements and is led out to the outside from a first side surface of the outer resin body, wherein the first terminal is provided with a first through-hole that is at least partially enclosed in the outer resin body on the first side surface, and when the outer resin body is viewed in plan from a direction perpendicular to the bottom surface, the first through-hole is located only inside the contour of the outer resin body.

[0009] To solve the above problems, a method for manufacturing a laminated solid electrolytic capacitor according to one aspect of the present disclosure comprises: a laminate in which a plurality of capacitor elements are stacked; an outer resin body having a box-like outer shape and enclosing the laminate; and a first terminal located inside the outer resin body, electrically connected to either the anode or cathode of the capacitor elements and extending outwards from a first side surface of the outer resin body, wherein the first terminal is provided with a first through-hole on the first side surface, at least a portion of which is enclosed within the outer resin body, and the outer resin body is laid flat from a direction perpendicular to the bottom surface. A method for manufacturing a laminated solid electrolytic capacitor, wherein, when viewed from the surface, the first through-hole is located only inside the contour of the outer resin body, comprising: a molding step of injecting resin between a first mold on the bottom side and a second mold on the top side facing the bottom side to form the outer resin body; and a blasting step of removing burrs that have formed on the outer resin body near the boundary between the first mold and the second mold by the molding step by projecting blast particles onto the outer resin body from at least one direction, the bottom side and the top side.

[0010] According to one aspect of this disclosure, a multilayer solid electrolytic capacitor can be realized that employs anode or cathode terminals with through holes, while preventing defects caused by foreign matter resulting from molding or blasting.

[0011] This is a perspective view showing the appearance of a multilayer solid electrolytic capacitor according to Embodiment 1 of the present invention. This is a front view of the above multilayer solid electrolytic capacitor. This is a diagram illustrating the manufacturing method of the above multilayer solid electrolytic capacitor. This shows a patterned metal plate for forming a lead frame. This is a diagram illustrating the manufacturing method of the above multilayer solid electrolytic capacitor. This shows the state in which the laminate is mounted on the anode terminal and cathode terminal. This is a diagram illustrating the manufacturing method of the above multilayer solid electrolytic capacitor. This shows the state in which the outer resin body is molded. This is a partially enlarged front view of the above multilayer solid electrolytic capacitor. This is a partially enlarged plan view in the manufacturing process of the above multilayer solid electrolytic capacitor. This is a partially enlarged bottom view in the manufacturing process of the above multilayer solid electrolytic capacitor. This is a partially enlarged front view of a multilayer solid electrolytic capacitor according to Embodiment 2 of the present invention.

[0012] [Embodiment 1] Hereinafter, a laminated solid electrolytic capacitor according to one embodiment of the present disclosure will be described in detail. A laminated solid electrolytic capacitor is a capacitor component that includes a laminate in which a plurality of capacitor elements to which a solid electrolyte such as a conductive polymer is applied are stacked.

[0013] <Appearance and Internal Structure of the Multilayer Solid Electrolytic Capacitor 1> Figure 1 is a perspective view showing the appearance of the multilayer solid electrolytic capacitor 1 according to Embodiment 1. Figure 2 is a front view of the multilayer solid electrolytic capacitor 1. The multilayer solid electrolytic capacitor 1 comprises an anode terminal 10, a cathode terminal 20, and an outer resin body 40. The anode terminal 10 is a terminal electrically connected to each anode 31 of a plurality of capacitor elements 30 (see Figure 4). The cathode terminal 20 is a terminal electrically connected to each cathode 32 of a plurality of capacitor elements 30. Either the anode terminal 10 or the cathode terminal 20 corresponds to the first terminal, and the other corresponds to the second terminal.

[0014] The outer resin body 40 encloses and seals a laminate 30S (see Figure 4) in which multiple capacitor elements 30 are stacked. The outer resin body 40 has a box-like shape. The outer resin body 40 is roughly rectangular in shape. The bottom surface 45F and top surface 46F of the roughly rectangular outer resin body 40 are roughly rectangular. The bottom surface 45F and top surface 46F are opposing surfaces. The bottom surface 45F is the surface facing the circuit board when the laminated solid electrolytic capacitor 1 as an electronic component is mounted on the circuit board.

[0015] As shown in each figure, including Figure 1, in this description, the Z-axis is defined as the direction perpendicular to the main surface of the bottom surface 45F and the main surface of the top surface 46F of the outer resin body 40. The top surface 46F is located on the positive side of the Z-axis direction relative to the bottom surface 45F. The positive side of the Z-axis direction is sometimes referred to as the upper side, and the negative side as the lower side. The Z-axis direction is also referred to as the vertical direction. The X-axis and Y-axis are parallel to the main surface of the bottom surface 45F and the main surface of the top surface 46F, respectively. The X-axis and Y-axis are parallel to the short side and long side of the roughly rectangular bottom surface 45F and top surface 46F, respectively. A view of the laminated solid electrolytic capacitor 1 in the negative direction of the X-axis is defined as the front view. A view of the laminated solid electrolytic capacitor 1 in the negative direction of the Z-axis is defined as the plan view, and a view in the positive direction is defined as the bottom view.

[0016] The height (vertical length) of the roughly rectangular resin outer casing 40 is smaller than the length of the longer side of the roughly rectangular base 45F and top 46F. That is, the length of the roughly rectangular resin outer casing 40 in the Z-axis direction is smaller than the length in the Y-axis direction. For this reason, the Y-axis direction of the multilayer solid electrolytic capacitor 1 is also referred to as the longitudinal direction, and the X-axis direction is also referred to as the width direction. Furthermore, typically, the height of the roughly rectangular resin outer casing 40 is smaller than the length of the shorter side of the roughly rectangular base 45F and top 46F.

[0017] The exterior resin body 40 is composed of an upper resin body 40A and a lower resin body 40B. The upper resin body 40A occupies approximately the upper half of the exterior resin body 40, and the lower resin body 40B occupies approximately the lower half of the exterior resin body 40. A boundary line 40C is formed at the boundary between the upper resin body 40A and the lower resin body 40B on the surface of the exterior resin body 40. The boundary line 40C is formed approximately in the center of the Z-axis direction of each of the four sides 41F to 44F of the exterior resin body 40. The boundary line 40C encircles the surface of the exterior resin body 40. Note that the exterior resin body 40 itself is a single resin part, and the boundary line 40C merely separates the upper resin body 40A from the lower resin body 40B.

[0018] Above and below the boundary line 40C, the cross-section perpendicular to the Z-axis is slightly larger for the upper resin body 40A than for the lower resin body 40B. That is, above and below the boundary line 40C, the length in the Y-axis direction is slightly larger for the upper resin body 40A than for the lower resin body 40B. Therefore, as shown in Figure 2, a small step difference is created above and below the boundary line 40C on the sides 43F and 44F of the exterior resin body 40, where the main surface is approximately perpendicular to the Y-axis. A gate mark 40G, which will be described in detail later, is located near the center of one of the sides 41F and 42F that are approximately perpendicular to the X-axis. The gate mark 40G is an elongated, approximately rectangular shape extending in the Y-axis direction. The longer side of the gate mark 40G on the positive Z-axis side (upper side) coincides with the boundary line 40C.

[0019] The capacitor element 30, which constitutes the laminate 30S enclosed within the outer resin body 40, is based on known technology and will be briefly explained. One end of a foil or thin sheet of aluminum or other valve-acting metal, on which a dielectric oxide film is formed on the surface, serves as the anode 31. Furthermore, a conductive layer is formed as the cathode 32, which covers the dielectric oxide film with a solid electrolyte made of a conductive polymer or the like, and the solid electrolyte is made of a conductive paste or the like. An insulating resist tape is placed between the anode 31 and the cathode 32 on the surface of the capacitor element 30.

[0020] A laminate 30S is formed by stacking multiple capacitor elements 30 such that the anodes 31 of the capacitor elements 30 overlap with each other, and the cathodes 32 overlap with each other. As shown in Figure 4, the laminate 30S is mounted on the anode terminal 10 and the cathode terminal 20, straddling these terminals.

[0021] Therefore, a flat first region 11 is provided at the inner end of the outer resin body 40 of the anode terminal 10, on which the anode 31 of the stacked capacitor elements 30 is mounted. Similarly, a flat first region 21 is provided at the inner end of the outer resin body 40 of the cathode terminal 20, on which the cathode 32 of the stacked capacitor elements 30 is mounted. The first region 11 of the anode terminal 10 and the first region 21 of the cathode terminal 20 are each composed of a plane (XY plane) that is substantially perpendicular to the Z axis.

[0022] The metal plate 60 is bent to form a second region 12 that follows the first region 11 at the anode terminal 10 (Figures 3 and 4). The second region 12 is approximately perpendicular to the Y-axis. At the point in the manufacturing process shown in Figures 3 and 4, the metal plate 60 is further bent from the second region 12 so that the portion following the second region 12 is approximately perpendicular to the Z-axis. Of the portion following the second region 12, the region immediately adjacent to the second region 12 becomes the third region 13, which will be described later (Figure 2).

[0023] Further bending of the metal plate 60 creates a third region 13 in the anode terminal 10 that follows the second region 12. The third region 13 is approximately perpendicular to the Z-axis. As described above, after the metal plate 60 is bent from the second region 12 so as to be approximately perpendicular to the Z-axis, the metal plate 60 is further bent so as to be approximately perpendicular to the Y-axis, forming the third region 13 as shown in Figure 2. A through hole 10H is provided in the center of the anode terminal 10 in the X-axis direction (width direction), extending from the region corresponding to this third region 13 to the second region 12 (Figure 3). The patterned portion of the metal plate 60 corresponding to the anode terminal 10 is in an unbent, flat state, and the opening shape of the through hole 10H may be, for example, a square, rectangle, or circle.

[0024] At the cathode terminal 20, the metal plate 60 is bent to form a second region 22 that follows the first region 21. The second region 22 is approximately perpendicular to the Y-axis. At the point in the manufacturing process shown in Figures 3 and 4, the metal plate 60 is further bent from the second region 22 so that the portion following the second region 22 is approximately perpendicular to the Z-axis. Of the portion following the second region 22, the region immediately adjacent to the second region 22 becomes the third region 23, which will be described later (Figures 2, 6, and 8).

[0025] The metal plate 60 is bent to form a third region 23 in the cathode terminal 20 that follows the second region 22. The third region 23 is approximately perpendicular to the Z axis. As described above, after the metal plate 60 is bent from the second region 22 so as to be approximately perpendicular to the Z axis, the metal plate 60 is further bent so as to be approximately perpendicular to the Y axis, forming the third region 23 as shown in Figure 2. The cathode terminal 20 has a through hole 20H in the center of the X-axis direction (width direction) of the cathode terminal 20, extending from the region corresponding to this third region 23 to the second region 22 (Figures 3, 6 and 8). The patterned portion of the metal plate 60 corresponding to the cathode terminal 20 is in an unbent, flat state, and the opening shape of the through hole 10H may be, for example, a square, rectangle, or circle.

[0026] Furthermore, the cathode terminal 20 is provided with a pair of sixth regions 26 to cover at least a portion of the side surface of the laminate 30S (Figure 4). The sixth regions 26 are integrally formed by folding both sides of the first region 21 of the patterned metal plate 60 in the X-axis direction (width direction), sandwiching the first region 21 between them. Each sixth region 26 is composed of a plane (YZ plane) substantially perpendicular to the X-axis. Either the through hole 10H provided in the anode terminal 10 or the through hole 20H provided in the cathode terminal 20 corresponds to the first through hole, and the other corresponds to the second through hole.

[0027] In the patterned metal plate 60 shown in Figure 3, the laminate 30S is mounted in the state shown in Figure 4, in the portion corresponding to each laminated solid electrolytic capacitor 1. Here, the cathode 32 of each capacitor element 30 is fixed to the first region 21 or the sixth region 26 of the cathode terminal 20 using a conductive adhesive or by other known methods, and is electrically connected. The anode 31 of each capacitor element 30 is fixed to the first region 11 of the anode terminal 10 by welding or by other known methods, and is electrically connected.

[0028] A portion of the anode terminal 10 is enclosed within the outer resin body 40, while the other portion is exposed from the outer resin body 40. A portion of the cathode terminal 20 is enclosed within the outer resin body 40, while the other portion is exposed from the outer resin body 40.

[0029] The anode terminal 10 is drawn out from one of the sides 43F and 44F of the outer resin body 40, whose main surface is substantially perpendicular to the Y-axis, in the third region 13 of the anode terminal 10. The cathode terminal 20 is drawn out from the other side 43F and 44F of the outer resin body 40, whose main surface is substantially perpendicular to the Y-axis, in the third region 23 of the cathode terminal 20. The sides from which the anode terminal 10 is drawn out and the sides from which the cathode terminal 20 is drawn out are the opposite sides 43F and 44F. One of the sides 43F and 44F corresponds to the first side, and the other corresponds to the second side.

[0030] In the multilayer solid electrolytic capacitor 1 according to Embodiment 1 shown in Figures 1 and 2, the anode terminal 10 is drawn out from the negative side surface 43F in the Y-axis direction, and the cathode terminal 20 is drawn out from the positive side surface 44F in the Y-axis direction. Hereinafter, unless otherwise specified, the description will focus on the side surfaces that are substantially perpendicular to the Y-axis from which the anode terminal 10 and cathode terminal 20 are drawn out, in the case of the multilayer solid electrolytic capacitor 1 according to Embodiment 1 shown in Figures 1 and 2.

[0031] As shown in Figures 1 and 2, at the position where the anode terminal 10 is drawn out, the upper surface of the anode terminal 10 substantially coincides with the boundary line 40C. That is, the anode terminal 10 is drawn out from the lower resin body 40B of the outer resin body 40. In this way, the anode terminal 10 is drawn out in the third region 13 from approximately the center in the Z-axis direction of the outer resin body 40, and is further bent toward the negative side (downward) in the Z-axis direction so as to follow the drawn-out side surface 43F. Furthermore, the anode terminal 10 is bent at the position where it reaches the bottom surface 45F so as to follow the bottom surface 45F.

[0032] The region of the anode terminal 10 following the third region 13, from when it is bent downwards in the negative Z-axis direction to when it is further bent along the bottom surface 45F, is referred to as the fourth region 14. The region following the fourth region 14 along the bottom surface 45F is referred to as the fifth region 15 of the anode terminal 10. The fourth region 14 is approximately perpendicular to the Y-axis. The fifth region 15 is the part that is approximately parallel (approximately parallel to the XY plane) to the main surface of the top surface 46F or the main surface of the bottom surface 45F. Alternatively, the anode terminal 10 drawn out from the lower resin body 40B may be bent at approximately a right angle from the Y-axis tip downwards in the negative Z-axis direction to form the fifth region 15, and then bent along the side surface 43F to form the fourth region 14.

[0033] At the position where the cathode terminal 20 is drawn out, the upper surface of the cathode terminal 20 coincides approximately with the boundary line 40C. That is, the cathode terminal 20 is drawn out from the lower resin body 40B of the outer resin body 40. In this way, the cathode terminal 20 is drawn out in the third region 23 from approximately the center in the Z-axis direction of the outer resin body 40, and is further bent toward the negative side (downward) in the Z-axis direction so as to follow the drawn-out side surface 44F. Furthermore, the cathode terminal 20 is bent at the position where it reaches the bottom surface 45F so as to follow the bottom surface 45F.

[0034] The region of the cathode terminal 20 following the third region 23, from when it is bent downwards in the negative Z-axis direction to when it is further bent along the bottom surface 45F, is referred to as the fourth region 24. The region following the fourth region 24 along the bottom surface 45F is referred to as the fifth region 25 of the cathode terminal 20. The fourth region 24 is approximately perpendicular to the Y-axis. The fifth region 25 is the part that is approximately parallel (approximately parallel to the XY plane) to the main surface of the top surface 46F or the main surface of the bottom surface 45F. Alternatively, the cathode terminal 20 drawn out from the lower resin body 40B may be bent at approximately a right angle from the Y-axis tip downwards in the negative Z-axis direction to form the fifth region 25, and then bent along the side surface 44F to form the fourth region 24.

[0035] The bottom surface 45F of the outer resin body 40 is provided with a projection 453 in the center in the Y-axis direction, which protrudes more in the negative Z-axis direction than the rest of the body. Therefore, the bottom surface 45F has stepped portions 451 and 452 that are set back in the positive Z-axis direction from the projection 453. The fifth region 15 of the anode terminal 10 is positioned on the stepped portion 451, and a part of it is positioned slightly in the negative Z-axis direction (downward) than the position of the projection 453 on the bottom surface 45F.

[0036] Similarly, the fifth region 25 of the cathode terminal 20 is positioned on the stepped portion 452, and a portion of it is positioned slightly to the negative side (downward) in the Z-axis direction than the position of the bottom surface 45F of the protruding portion 453. In this way, when the multilayer solid electrolytic capacitor 1 is mounted on the circuit board described above, the fifth region 15 of the anode terminal 10 and the fifth region 25 of the cathode terminal 20 can each be connected to electrode pads provided on the circuit board.

[0037] <Method for Manufacturing a Multilayer Solid Electrolytic Capacitor 1> Next, the method for manufacturing a multilayer solid electrolytic capacitor 1 will be explained with reference to Figures 3 to 8.

[0038] The anode terminal 10 and cathode terminal 20 of the multilayer solid electrolytic capacitor 1 are formed as a lead frame. Therefore, a metal plate 60 is prepared on which the wiring that will constitute the anode terminal 10 and cathode terminal 20 of a large number of multilayer solid electrolytic capacitors 1 is patterned. Next, the prepared metal plate 60 is bent to form the first regions 11, 21, the second regions 12, 22, and the sixth region 26 of the anode terminal 10 and cathode terminal 20. Figure 3 is a diagram showing the state in which the patterned metal plate 60 for forming such a lead frame has been bent. After that, the laminate 30S is mounted on the metal plate 60. Figure 4 is a plan view showing the portion of the patterned metal plate 60 in Figure 3 corresponding to one multilayer solid electrolytic capacitor 1, and the state in which the laminate 30S is mounted on the anode terminal 10 and cathode terminal 20.

[0039] Next, in the molding process, the outer resin body 40 of each laminated solid electrolytic capacitor 1 is molded to enclose each laminated body 30S. Figure 5 is a diagram illustrating the point in the manufacturing process after the laminated bodies 30S of each laminated solid electrolytic capacitor 1 have been mounted on the patterned metal plate 60 in the state shown in Figure 3, and after the outer resin body 40 has been formed.

[0040] The exterior resin body 40 is molded by injecting resin between the first mold on the bottom surface 45F side and the second mold on the top surface 46F side and allowing it to harden. The first mold on the bottom surface 45F side is also referred to as the lower mold, and the second mold on the top surface 46F side is also referred to as the upper mold. The first mold and the second mold together are also referred to as the upper and lower molds.

[0041] The runner 70 is a channel for the uncured resin that is poured between the upper and lower mold frames. The gate connection portion 71 of the runner 70 is the part that connects to the gate, which is the resin injection port provided between the upper and lower mold frames. The gate marks 40G on the outer resin body 40 shown in Figures 1 and 2 are traces of such a gate. In the molding process, the laminate 30S, which is mounted on a lead frame and fixed and electrically connected, is placed inside the upper and lower mold frames. Then, resin is injected into the upper and lower mold frames from the runner 70, and after the resin hardens, the outer resin body 40 and the runner 70 are removed from the upper and lower mold frames, and the outer resin body 40 and the gate connection portion 71 are separated. At this time, gate marks 40G are formed on the outer resin body 40.

[0042] The boundary line 40C in the outer resin body 40 corresponds to the boundary between the upper and lower moldwork. During mold molding, the anode terminal 10 and cathode terminal 20 are sandwiched between the upper and lower moldwork. Therefore, as shown in Figures 1 and 2, the anode terminal 10 and cathode terminal 20 are in contact with the boundary line 40C of the outer resin body 40.

[0043] Although not shown in Figure 5, after molding, burrs are formed on the outer resin body 40, which are hardened resin that has overflowed at the boundary between the upper and lower molds. Specifically, after molding, burrs are formed on the sides 41F to 44F of the outer resin body 40, protruding along the boundary line 40C. Such burrs need to be removed before the multilayer solid electrolytic capacitor 1 becomes the final product. Therefore, a process to remove the burrs is performed after molding.

[0044] From the perspective of productivity, it is efficient to perform such a burr removal step by blasting. Blasting is a treatment that performs some processing on an object by spraying solid particles, also referred to as blast particles, in a state mixed with a fluid. In the present embodiment, as a blasting step, blast particles are sprayed in a blasting process to remove burrs protruding from the side surfaces 41F to 44F. The spraying of the blast particles is performed from the Z-axis direction (vertical direction). In particular, in order to prevent untreated burrs from remaining due to shielding by the upper resin body 40A or the lower resin body 40B, it is preferable that the projection is performed at an angle to the Z-axis direction (vertical direction) from both sides in the vertical direction.

[0045] After the blasting treatment, portions to become the anode terminal 10 and the cathode terminal 20 are cut out from the patterned metal plate 60 shown in Fig. 5. Thereafter, the portion exposed to the outside of the exterior resin body 40 is bent twice as the anode terminal 10, whereby a third region 13, a fourth region 14, and a fifth region are partitioned. Similarly, the portion exposed to the outside of the exterior resin body 40 is bent twice as the cathode terminal 20, whereby a third region 23, a fourth region 24, and a fifth region 25 are partitioned. In this way, the multilayer solid electrolytic capacitor 1 shown in Fig. 1 and Fig. 2 is manufactured.

[0046] Details of the through-hole 20H of the cathode terminal 20 will be described below with reference to Fig. 6, and the same applies to the anode terminal 10. Fig. 6 is a partially enlarged front view of the multilayer solid electrolytic capacitor 1, and shows an enlarged view of the portion within frame p6 in Fig. 2. In other words, Fig. 6 is a front view of the multilayer solid electrolytic capacitor 1, with the vicinity of the position from which the cathode terminal 20 is drawn out being enlarged. In Fig. 6, the position of the cathode terminal 20 inside the exterior resin body 40 is indicated by a dotted line.

[0047] The fourth region 24 of the cathode terminal 20 disposed outside the exterior resin body 40 is a portion substantially orthogonal to the Y-axis and along the side surface 44F. The second region 22 of the cathode terminal 20 disposed inside the exterior resin body 40 is substantially orthogonal to the Y-axis, and is also a portion along the side surface 44F. The third region 23 between the second region 22 and the fourth region 24 is located at a portion where the cathode terminal 20 is drawn out from the exterior resin body 40. The third region 23 is substantially orthogonal to the Z-axis.

[0048] The cathode terminal 20 is provided with a through hole 20H extending from the second region 22 to the third region 23. In FIG. 6, the range of the through hole 20H in the cathode terminal 20 is also shown by a dotted line. As described above, the cathode terminal 20 is provided with the through hole 20H at least partially enclosed in the exterior resin body 40 on the side surface 44F of the exterior resin body 40. That is, at least a part of the through hole 20H is enclosed in the resin constituting the exterior resin body 40.

[0049] The through hole 20H provided in the cathode terminal 20 is located only inside the outline of the exterior resin body 40 when the exterior resin body 40 is viewed in a plan view from a direction orthogonal to the main surface of the bottom surface 45F, that is, from the Z-axis direction. In other words, in the blasting step, the through hole 20H is disposed at a position that is not exposed to blast particles projected from the positive side toward the negative side in the Z-axis direction. To this extent, when the third region 23 of the cathode terminal 20 is viewed in the positive direction along the Z-axis, that is, when the third region 23 is viewed from the bottom surface 45F side, a part of the through hole 20H may be exposed from the exterior resin body 40. FIGS. 6 to 8 show such a situation.

[0050] According to Embodiment 1, the cathode terminal 20 is enclosed within the outer resin body 40 such that at least a portion of the through-hole 20H of the cathode terminal 20 is enclosed within the resin constituting the outer resin body 40. Therefore, even if an external force is applied to the exposed portion of the cathode terminal 20, the force is less likely to be applied to the inner portion of the outer resin body 40. In other words, the resin penetrating the through-hole 20H acts as an anchor, making it difficult for the external force to be transmitted to the cathode terminal 20 on the inner side of the outer resin body 40. As a result, the close contact between the outer resin body 40 and the cathode terminal 20 is maintained, and the occurrence of the phenomenon of the cathode terminal 20 peeling off from the outer resin body 40 is suppressed. Furthermore, this maintains the sealing of the laminate 30S, and the deterioration of the characteristics of the laminated solid electrolytic capacitor 1 is suppressed.

[0051] From the viewpoint of fully utilizing the anchoring effect of the resin penetrating the through-hole 20H, the width (length in the X-axis direction) of the portion of the opening of the through-hole 20H provided in the cathode terminal 20, which is made of a thin metal plate, that is enclosed in the outer resin body 40 is preferably 20% or more of the width (length in the X-axis direction) of the cathode terminal 20, and the sum of the depth (length in the Y-axis direction) and height (length in the Z-axis direction) of the enclosed portion is preferably 25% or more of the height (length in the Z-axis direction) of the outer resin body 40. In this case, the width of the cathode terminal 20 in the third region 23 is preferably about 0.5 to 3 mm, and the height of the outer resin body 40 is preferably about 1 mm to 3 mm. The width, depth, and height of the opening of the through-hole 20H are evaluated along the surface of the metal plate constituting the cathode terminal 20.

[0052] <Effects, etc.> In the multilayer solid electrolytic capacitor according to Embodiment 1, the through holes 10H and 20H provided in the anode terminal 10 and cathode terminal 20 are located inside the contour of the outer resin body 40. Therefore, even if the outer resin is enclosed inside the through holes 10H and 20H during the molding process, it is located inside the contour of the outer resin body 40 and does not become a burr that needs to be removed as in the conventional method.

[0053] Furthermore, when the through-holes 10H and 20H are viewed from above in the positive Z-axis direction of the outer resin body 40, the upper resin body 40A acts as a shield, concealing them. Therefore, when blast particles are projected from above in the Z-axis direction, the through-holes 10H and 20H are not exposed to the blast particles, and the blast particles do not clog the through-holes 10H and 20H. On the other hand, when blast particles are projected from below in the Z-axis direction, the through-holes 10H and 20H have exposed portions and can be exposed to the blast particles. However, clogging of the through-holes by blast particles is due to the fact that the diameter of the exposed portion of the through-hole is close to the diameter of the blast particles. Although the through-holes 10H and 20H are exposed from the outer resin body 40, their exposed portions are located between the contour of the lower resin body 40B and the contour of the upper resin body 40A, making it possible to make the diameter of the exposed portion sufficiently smaller than the diameter of the blast particles. Therefore, even when blast particles are projected from the lower side in the Z-axis direction, the blast particles do not clog the through holes 10H and 20H.

[0054] Therefore, in the stacked solid electrolytic capacitor according to Embodiment 1, the formation of burrs inside the through holes 10H and 20H can be suppressed, reducing the intensity of the blast treatment, and the clogging of the through holes 10H and 20H by blast particles can be suppressed. As a result, defects caused by foreign matter resulting from mold molding or blast treatment can be prevented.

[0055] [Embodiment 2] The laminated solid electrolytic capacitor 1B according to Embodiment 2 is the same as the laminated solid electrolytic capacitor 1 according to Embodiment 1, except that the position of the through hole 10H provided in the anode terminal 10 and the position of the through hole 20H provided in the cathode terminal 20 are different from those of Embodiment 1. Figure 9 is a partially enlarged front view of the laminated solid electrolytic capacitor 1B according to Embodiment 2, and is a figure corresponding to Figure 6 used to explain the laminated solid electrolytic capacitor 1 in Embodiment 1. The cathode terminal 20 will be explained below with reference to Figure 9, but the same applies to the anode terminal 10.

[0056] The through-hole 20H provided in the cathode terminal 20 of the laminated solid electrolytic capacitor 1B according to Embodiment 2 is positioned closer to the inside of the outer resin body 40 in the third region 23 compared to the laminated solid electrolytic capacitor 1 according to Embodiment 1. That is, in Figure 9, the through-hole 20H provided in the cathode terminal 20 is positioned closer to the negative side in the Y-axis direction. In other words, the entire through-hole 20H is enclosed within the outer resin body 40. More specifically, the entire through-hole 20H is enclosed within the lower resin body 40B portion of the outer resin body 40.

[0057] In the stacked solid electrolytic capacitor 1B according to Embodiment 2, no burrs are formed in the through holes 10H and 20H provided in the anode terminal 10 and cathode terminal 20 during the molding process. Furthermore, the through holes 10H and 20H are not exposed to blast particles during the blasting process. Therefore, in Embodiment 2 as well, it is possible to prevent defects caused by foreign matter resulting from molding and blasting.

[0058] The present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in the embodiments are also included in the technical scope of the present invention. Furthermore, although examples are shown in each embodiment in which through holes are provided in both the anode terminal 10 and the cathode terminal 20, through holes may be provided in only one of them.

[0059] 1, 1B Multilayer Solid Electrolytic Capacitor 10 Anode terminals (first terminal, second terminal) 10H Through-holes (first through-hole, second through-hole) 20 Cathode terminals (first terminal, second terminal) 20H Through-holes (first through-hole, second through-hole) 30S Laminate 30 Capacitor element 31 Anode 32 Cathode 40 Resin casing 40C Boundary line 41F, 42F Sides 43F, 44F Sides (first side, second side) 45F Bottom 46F Top

Claims

1. A laminated solid electrolytic capacitor comprising: a laminate in which a plurality of capacitor elements are stacked; an outer resin body having a box-like shape and enclosing the laminate; and a first terminal located inside the outer resin body, electrically connected to either the anode or cathode of the capacitor elements, and extending outwards from a first side surface of the outer resin body, wherein the first terminal is provided with a first through-hole, at least a portion of which is enclosed within the outer resin body on the first side surface, and when the outer resin body is viewed in plan from a direction perpendicular to the bottom surface, the first through-hole is located only inside the contour of the outer resin body.

2. The laminated solid electrolytic capacitor according to claim 1, wherein the outer resin body has an integrally formed upper resin body on the top surface side and a lower resin body on the bottom surface side having a smaller contour than the upper resin body, the first terminal is drawn out from the lower resin body on the first side surface of the outer resin body, and when the outer resin body is viewed in plan from a direction perpendicular to the bottom surface, a part of the first through hole is located inside the contour of the upper resin body and outside the contour of the lower resin body.

3. The laminated solid electrolytic capacitor according to claim 1, wherein the entirety of the first through-hole is enclosed within the outer resin body.

4. The laminated solid electrolytic capacitor according to any one of claims 1 to 3, wherein the width of the portion of the opening of the first through hole that is enclosed in the outer resin body is 20% or more of the width of the first terminal, and the sum of the depth and height of the portion enclosed in the outer resin body is 25% or more of the height of the outer resin body.

5. The laminated solid electrolytic capacitor according to any one of claims 1 to 3, further comprising a second terminal located inside the outer resin body, electrically connected to the other of the anode or cathode of the capacitor element, and extending outwards from a second side surface of the outer resin body, wherein the second terminal is provided with a second through-hole, at least a portion of which is enclosed within the outer resin body on the second side surface, and when the outer resin body is viewed in plan from a direction perpendicular to the bottom surface, the second through-hole is located only inside the contour of the outer resin body.

6. A method for manufacturing a laminated solid electrolytic capacitor, comprising: a laminate in which a plurality of capacitor elements are stacked; an outer resin body having a box-shaped outer form and enclosing the laminate; and a first terminal located inside the outer resin body, electrically connected to either the anode or cathode of the capacitor elements and extending outwards from a first side surface of the outer resin body, wherein the first terminal is provided with a first through-hole on the first side surface, at least a portion of which is enclosed within the outer resin body, and when the outer resin body is viewed in plan from a direction perpendicular to the bottom surface, the first through-hole is located only inside the contour of the outer resin body, the method comprising: a molding step of injecting resin between a first mold on the bottom surface side and a second mold on the top surface side facing the bottom surface to form the outer resin body; A method for manufacturing a laminated solid electrolytic capacitor, comprising: a blasting step of removing burrs that have formed in the vicinity of the boundary between the first mold and the second mold by the molding step, by projecting blast particles onto the outer resin body from at least one direction, the bottom side and the top side.

Images