JP2014204059A - Solid electrolytic capacitor and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solid electrolytic capacitor in which increase in leakage current is suppressed, and to provide a manufacturing method therefor.SOLUTION: A solid electrolytic capacitor includes an exterior body 2 covering a capacitor element 1, an anode lead-out structure 3 having an anode terminal 31 exposed to the lower surface 2a of the exterior body 2, and a cathode lead-out structure 4 having a cathode terminal 41 exposed to the lower surface 2a of the exterior body 2. In the anode lead-out structure 3, a facing portion 32 faces the upper surface 31b of the anode terminal 31, and a gap Rg is formed between the upper surface 31b of the anode terminal 31 and the facing portion 32. A coupling part 33 couples the edge 31c of the anode terminal 31 located on the cathode terminal 41 side and the first edge 32a of the facing portion 32. The coupling part 33 is provided with an opening 35 communicating with the gap Rg. The opening 35 and the gap Rg are filled with a portion of a resin composing the exterior body 2.

Description

  The present invention relates to a solid electrolytic capacitor in which an exterior body is formed by a resin mold and a method for manufacturing the same.

  FIG. 7 is a sectional view conceptually showing a conventional solid electrolytic capacitor. As shown in FIG. 7, the solid electrolytic capacitor includes a capacitor element 81, an exterior body 82 covering the capacitor element 81, an anode terminal 83, and a cathode terminal 84 (see, for example, Patent Document 1). The capacitor element 81 includes an anode body 811 made of a porous sintered body, an anode lead 812 planted on the anode body 811, and a dielectric layer 813 formed on the surface of a conductive material constituting the anode body 811. And an electrolyte layer 814 formed on the surface of the dielectric layer 813, and a cathode layer 815 formed on the outer peripheral surface of the electrolyte layer 814. FIG. 7 schematically shows only a portion of the dielectric layer 813 formed on the outer peripheral surface of the anode body 811, but the dielectric layer 813 is a fine layer existing in the anode body 811. It is also formed on the inner peripheral surface of the hole.

  The anode terminal 83 is formed in an inverted T shape by bending and crushing a single frame. The facing portions 831 and 832 generated by the bending process are crushed by crushing so that they are in close contact with each other and the total thickness thereof is approximately the same as the thickness of the frame. A terminal portion 833 extending in the lateral direction of the anode terminal 83 has a lower surface 833 a exposed from the lower surface 82 a of the exterior body 82. Further, the connecting portion 834 extending in the vertical direction of the anode terminal 83 is electrically connected to the anode lead 812. The cathode terminal 84 has a lower surface 84 a exposed from the lower surface 82 a of the exterior body 82, and is electrically connected to the cathode layer 815 through the conductive adhesive 86.

  The exterior body 82 is formed by resin molding after the capacitor element 81 is connected to the anode terminal 83 and the cathode terminal 84. FIG. 8 is a cross-sectional view used for explaining the resin molding process. First, the capacitor element 81, the anode terminal 83, and the cathode terminal 84 are disposed in the mold 87. At this time, the lower surface 833 a of the terminal portion 833 of the anode terminal 83 and the lower surface 84 a of the cathode terminal 84 are brought into surface contact with the bottom surface 87 a in the mold 87. Next, the softened resin is poured into the mold 87 from one of the grooves 87 b and 87 c provided in the mold 87. At this time, the other groove may be closed or used as a resin outlet. After the inside of the mold 87 is filled with resin, the resin in the mold 87 is cured.

JP 2004-55889 A

  When the capacitor element 81 and the like are arranged in the mold 87 as shown in FIG. 8, the capacitor element 81 and the mold 87 are sandwiched between the anode terminal 83 and the cathode terminal 84 in the mold 87. A narrow space Rc is formed. When the resin is poured into the mold 87, the resin tends to flow into the space Rc with the gap provided between the capacitor element 81 and the anode terminal 83 as a main inlet Re (shown in FIG. 8). (See white arrow Fc). On the other hand, the air existing in the space Rc tends to escape from the inlet Re due to the pressure of the resin that enters the space Rc.

  Therefore, the resin and air hinder the movement of each other at the inlet Re, and as a result, the resin hardly flows into the space Rc and the pressure of the resin increases near the inlet Re. Along with this, pressure is applied to the anode lead 812 and the pressure increases. When pressure is applied to the anode lead 812, stress concentrates in a region of the anode body 811 near the base of the anode lead 812, and there is a risk that defects such as cracks may occur in the dielectric layer 813 formed in that region. It was. In particular, in the vicinity of the interface between the anode body 811 and the anode lead 812, the dielectric layer 813 is likely to have defects such as cracks. Such a defect causes an increase in the leakage current of the solid electrolytic capacitor.

  Therefore, an object of the present invention is to provide a solid electrolytic capacitor in which an increase in leakage current is suppressed and a method for manufacturing the same.

  The solid electrolytic capacitor according to the present invention includes a capacitor element having an anode member, a cathode member, and a dielectric member, an exterior body covering the capacitor element, an anode terminal portion exposed on the lower surface of the exterior body, and an anode member. An anode lead structure that is electrically connected, and a cathode lead structure that has a cathode terminal portion exposed on the lower surface of the exterior body and is electrically connected to the cathode member. The anode lead structure further includes a facing portion, a connecting portion, and a connecting portion. The facing portion faces the upper surface of the anode terminal portion, and a gap is provided between the upper surface and the facing portion. The connecting part connects the edge of the anode terminal part located on the cathode terminal part side and the first edge of the opposing part to each other. The connecting portion is coupled to the second end edge opposite to the first end edge of the facing portion, and is electrically connected to the anode member. The connecting portion is provided with an opening, and the opening communicates with a gap provided between the anode terminal portion and the facing portion. The opening and the gap are filled with a part of the resin constituting the exterior body.

  According to the solid electrolytic capacitor described above, the passage formed by the opening and the gap functions as a pressure-removing passage when the exterior body is formed (at the time of resin molding using the die). The resin spreads all over and the pressure of the resin in the mold becomes difficult to increase. Therefore, during formation of the exterior body, stress is hardly generated in the capacitor element, and accordingly, defects such as cracks are not easily generated in the dielectric member. As a result, an increase in leakage current is suppressed in the solid electrolytic capacitor.

  In the solid electrolytic capacitor, it is preferable that the opening extends along the edge of the anode terminal portion or the first edge of the facing portion.

  The manufacturing method according to the present invention includes a capacitor element having an anode member, a cathode member, and a dielectric member, an exterior body that covers the capacitor element, an anode terminal portion that is exposed on the lower surface of the exterior body, and is electrically connected to the anode member. A solid electrolytic capacitor comprising a positively connected anode lead structure and a cathode lead structure exposed to the lower surface of the exterior body and electrically connected to the cathode member Steps (a) to (d) are included. Steps (a) to (d) correspond to a frame preparation step, a frame processing step (mainly the first and second bending steps), a connection step, and a resin molding step, which will be described in the embodiments described later. doing.

  In the step (a), a flat frame having an upper surface and a lower surface, which becomes an anode lead structure, is prepared. The frame includes a first region serving as an anode terminal portion, a second region serving as a connecting portion that is in contact with an edge of the first region, and an edge of a second region opposite to the first region. A third region that is in contact with the second region and is a facing portion, a fourth region that is in contact with an edge of the third region opposite to the second region and is a connection portion, and a second region. And an opening formed through the frame from the upper surface to the lower surface. In the step (b), the third region is opposed to the first region by bending the second region, or by bending the frame at the edge of the first region and the edge of the second region. A gap is formed between the first region and the third region, and the frame is bent at the edge of the third region to change the posture of the fourth region. In this way, an anode lead structure having an anode terminal portion, a connecting portion, a facing portion, and a connecting portion is formed. After the step (b), in the state where the connecting portion and the opening are directed toward the cathode terminal portion, in the step (c), the anode member is electrically connected to the connection portion, and the cathode is formed on the upper surface of the cathode terminal portion. The members are electrically connected. After the step (c), in the step (d), an exterior body is formed by a resin mold using a mold. In the step (d), the capacitor element, the anode lead structure, and the cathode lead structure are arranged in the mold so that the bottom surface of the anode terminal portion and the bottom surface of the cathode terminal portion are in contact with the inner surface of the mold, and thereafter Pour the resin into the mold.

  Through the steps (a) and (b), the opening portion leads to a gap provided between the anode terminal portion and the facing portion. On the other hand, in the step (d), the lower surface of the anode terminal portion and the lower surface of the cathode terminal portion are brought into contact with the inner surface of the mold. For this reason, a narrow space sandwiched between the capacitor element and the mold is formed between the anode terminal portion and the cathode terminal portion in the mold. Here, according to the above manufacturing method, in the mold, the gap provided between the anode terminal portion and the facing portion leads to a narrow space through the opening. That is, as a passage leading to a narrow space, a passage different from a passage passing through the inlet provided between the capacitor element and the anode lead structure is formed by the opening and the gap. Therefore, when the resin is poured into the mold and the resin tries to enter the narrow space, the air in the space easily escapes to the outside through the opening and the gap. That is, the passage formed by the opening and the gap functions as a pressure relief passage. As a result, the resin easily flows into a narrow space, and the pressure of the resin hardly increases near the entrance of the space.

  Therefore, according to the above manufacturing method, stress is hardly generated in the capacitor element, and accordingly, defects such as cracks are hardly generated in the dielectric member. As a result, an increase in leakage current is suppressed in the manufactured solid electrolytic capacitor.

  In the step (a) of the manufacturing method, the opening preferably has a flat shape extending along the boundary line between the second region and the first or third region.

  According to the solid electrolytic capacitor and the manufacturing method thereof according to the present invention, an increase in leakage current is suppressed.

1 is a cross-sectional view conceptually showing a solid electrolytic capacitor according to an embodiment of the present invention. It is the conceptual diagram which showed the anode drawer structure shown by FIG. 1 seeing from the cathode drawer structure side. (A) The top view which showed the flame | frame prepared in the flame | frame preparation process performed with the manufacturing method of a solid electrolytic capacitor conceptually, (b) The cross section along the III-III line | wire shown by Fig.3 (a) FIG. It is sectional drawing used for description of (a) 1st bending process of the frame processing process performed with the manufacturing method of a solid electrolytic capacitor, (b) 2nd bending process, and (c) crushing process. It is sectional drawing used for description of the connection process performed with the manufacturing method of a solid electrolytic capacitor. It is sectional drawing used for description of the resin mold process performed with the manufacturing method of a solid electrolytic capacitor. It is sectional drawing which showed the conventional solid electrolytic capacitor notionally. It is sectional drawing used for description of the resin mold process performed in the manufacture process of the conventional solid electrolytic capacitor.

<Configuration of solid electrolytic capacitor>
FIG. 1 is a cross-sectional view conceptually showing a solid electrolytic capacitor according to an embodiment of the present invention. As shown in FIG. 1, the solid electrolytic capacitor includes a capacitor element 1, an exterior body 2, an anode lead structure 3, and a cathode lead structure 4. The capacitor element 1 has an anode body 11, an anode lead 12, a dielectric layer 13, an electrolyte layer 14, and a cathode layer 15.

  The anode body 11 is composed of a porous sintered body having conductivity. Various shapes such as a rectangular parallelepiped and a cylinder can be adopted as the shape of the anode body 11. The anode lead 12 is composed of a conductive wire. As the conductive material constituting the anode body 11 and the anode lead 12, the same kind or different kinds of materials are used. As the conductive material, valve metals such as titanium (Ti), tantalum (Ta), aluminum (Al), and niobium (Nb) are used. In particular, titanium, tantalum, aluminum, and niobium are suitable materials to be used because an oxide film (dielectric layer 13) having a higher dielectric constant is formed by oxidizing their surfaces. The conductive material may be an alloy containing a valve metal as a main component, such as an alloy made of two or more kinds of valve metals, an alloy made of a valve metal and another substance, or the like.

  The dielectric layer 13 is formed on the surface of the conductive material constituting the anode body 11 (the surface of the porous sintered body). The dielectric layer 13 is an oxide film formed by oxidizing the surface of the conductive material constituting the anode body 11. Therefore, the dielectric layer 13 is formed on the outer peripheral surface of the anode body 11 and the inner peripheral surface of fine holes existing in the anode body 11. In FIG. 1, only the portion of the dielectric layer 13 formed on the outer peripheral surface of the anode body 11 is schematically shown.

  The electrolyte layer 14 is formed on the surface of the dielectric layer 13. Specifically, the electrolyte layer 14 is formed on the outer peripheral surface of the dielectric layer 13 and inside the fine holes present in the anode body 11. In FIG. 1, only the portion of the electrolyte layer 14 formed on the outer peripheral surface of the dielectric layer 13 is schematically shown. As the electrolyte material constituting the electrolyte layer 14, a conductive inorganic material such as manganese dioxide, or a conductive organic material such as a TCNQ (Tetracyano-quinodimethane) complex salt or a conductive polymer is used. Note that various substances that are not limited to these conductive inorganic materials and conductive organic materials may be used as the electrolyte material.

  The cathode layer 15 is formed on the outer peripheral surface of the electrolyte layer 14. Specifically, the cathode layer 15 includes a carbon layer (not shown) formed on the outer peripheral surface of the electrolyte layer 14 and a silver paint layer (not shown) formed on the outer peripheral surface of the carbon layer. Has been. The cathode layer 15 is not limited to such a configuration, and various configurations having a current collecting function can be employed.

  The exterior body 2 covers the capacitor element 1. Here, the exterior body 2 is formed so that the lower surface 2 a thereof is substantially parallel to the extending direction of the anode lead 12. An electrically insulating resin is used as a constituent material of the exterior body 2. Preferably, a thermosetting resin such as an epoxy resin is used as a constituent material of the exterior body 2.

  The anode lead structure 3 is an electrode structure that draws an anode current path that leads to the anode lead 12 to the lower surface 2 a of the exterior body 2 by being electrically connected to the anode lead 12 of the capacitor element 1. The cathode lead structure 4 is an electrode structure that draws a cathode current path leading to the cathode layer 15 to the lower surface 2 a of the exterior body 2 by being electrically connected to the cathode layer 15 of the capacitor element 1. The anode lead structure 3 has a flat anode terminal part 31, and the cathode lead structure 4 has a flat cathode terminal part 41. Then, the lower surface 31a of the anode terminal portion 31 and the lower surface 41a of the cathode terminal portion 41 are exposed on the lower surface 2a of the exterior body 2, and the lower surface electrodes of the solid electrolytic capacitor are constituted by these lower surfaces 31a and 41a. .

  FIG. 2 is a conceptual diagram showing the anode lead structure 3 shown in FIG. 1 as viewed from the cathode lead structure 4 side. In FIG. 2, the illustration of the configuration other than the anode lead structure 3 is omitted. As shown in FIGS. 1 and 2, the anode lead structure 3 includes a facing portion 32, a connecting portion 33, and a connecting portion 34 in addition to the anode terminal portion 31. Here, the anode lead structure 3 is formed by bending one frame as will be described later.

  The facing portion 32 faces the upper surface 31 b of the anode terminal portion 31, and a gap Rg is provided between the upper surface 31 b and the facing portion 32. The gap Rg is a gap for constituting a pressure relief passage to be described later. Accordingly, the gap Rg extends along the facing portion 32 from the first end edge 32a of the facing portion 32 located on the cathode terminal portion 41 side to the second end edge 32b on the opposite side. The gap Rg only needs to be formed without being cut off from the first end edge 32a to the second end edge 32b. For example, the anode terminal portion 31 and the facing portion 32 may be partially in contact with each other. Good.

  The connecting portion 33 connects the end edge 31c of the anode terminal portion 31 located on the cathode terminal portion 41 side and the first end edge 32a of the facing portion 32 to each other. In the present embodiment, the connecting portion 33 is curved in a U shape. The connecting portion 33 is not limited to a U shape, and may have various shapes such as a V shape.

  The connecting portion 34 is connected to the second end edge 32 b of the facing portion 32. And the front-end | tip 34a of the connection part 34 is electrically connected to the anode lead 12 of the capacitor | condenser element 1 by connection means, such as welding. In the present embodiment, the connection portion 34 extends from the second end edge 32 b of the facing portion 32 to the anode lead 12 substantially perpendicularly to the upper surface 31 b of the anode terminal portion 31. The connecting portion 34 may be inclined with respect to the upper surface 31 b of the anode terminal portion 31, that is, may extend obliquely from the second end edge 32 b of the facing portion 32 toward the anode lead 12.

  The connecting portion 33 is provided with an opening 35, and the opening 35 communicates with a gap Rg provided between the anode terminal portion 31 and the facing portion 32. And the opening part 35 and the clearance gap Rg are filled with a part of resin which comprises the exterior body 2 (refer FIG. 1). In the present embodiment, the opening 35 extends along the end edge 31c of the anode terminal portion 31 or the first end edge 32a of the facing portion 32 (see FIG. 2).

  As shown in FIG. 1, the cathode lead structure 4 has an extending portion 42 in addition to the cathode terminal portion 41. The extending part 42 extends from the edge 41 c of the cathode terminal part 41 located on the anode terminal part 31 side toward the anode terminal part 31. The thickness of the extending portion 42 is smaller than the thickness of the cathode terminal portion 41, and the upper surface 41b of the cathode terminal portion 41 and the upper surface 42b of the extending portion 42 are aligned in substantially the same plane, while the lower surface 42a of the extending portion 42 Is shifted upward from the position of the lower surface 41 a of the cathode terminal portion 41. The lower surface 41 a of the cathode terminal portion 41 is exposed from the lower surface 2 a of the exterior body 2, while the lower surface 42 a of the extending portion 42 is covered with the exterior body 2. Further, the upper surface 41 b of the cathode terminal portion 41 and the upper surface 42 b of the extending portion 42 are electrically connected to the cathode layer 15 through the conductive adhesive 6.

<Method for manufacturing solid electrolytic capacitor>
Next, a method for manufacturing the solid electrolytic capacitor according to the present embodiment will be specifically described. In the manufacturing method of this embodiment, a frame preparation process, a frame processing process, a connection process, and a resin molding process are performed in order.

FIG. 3A is a plan view conceptually showing the frame prepared in the frame preparation process. Moreover, FIG.3 (b) is sectional drawing which follows the III-III line | wire shown by Fig.3 (a). FIG.
As shown in a) and (b), in the frame preparation step, a flat frame 7 having an anode frame portion 71 to be the anode extraction structure 3 and a cathode frame portion 72 to be the cathode extraction structure 4 is prepared. . The frame 7 is formed from a single metal plate, and the anode frame portion 71 and the cathode frame portion 72 are connected to each other via other portions (not shown) of the frame 7. Further, the anode frame portion 71 and the cathode frame portion 72 are arranged so as to be aligned in one direction (a predetermined direction Da shown in FIG. 3A), and their lower surfaces 71a and 72a are aligned on substantially the same plane. Yes.

  The anode frame portion 71 includes a first region 711 that becomes the anode terminal portion 31, a second region 712 that becomes the connecting portion 33, a third region 713 that becomes the facing portion 32, and a fourth region 714 that becomes the connection portion 34. And an opening 35 formed in the second region 712. In the anode frame portion 71, the first region 711, the second region 712, the third region 713, and the fourth region 714 are arranged in this order in a predetermined direction Da that is a direction from the anode frame portion 71 to the cathode frame portion 72. The fourth regions 714 are arranged so as to be arranged at a position closest to the cathode frame portion 72 while being arranged. Specifically, the second region 712 is in contact with the edge 711 a of the first region 711. The third region 713 is in contact with the edge 712 a of the second region 712 opposite to the first region 711. The fourth region 714 is in contact with the edge 713 a of the third region 713 opposite to the second region 712. In the present embodiment, the fourth region 714 has a tongue shape. The opening 35 penetrates the frame 7 from the upper surface to the lower surface in the second region 712.

  In the present embodiment, the boundary line B1 (matches the edge 711a) between the first region 711 and the second region 712, the boundary line B2 (matches the edge 712a) between the second region 712 and the third region 713, The edge 713a of the third region 713 is set so that both are substantially perpendicular to the predetermined direction Da. And the opening part 35 is exhibiting the flat shape expanded along the boundary line B1 or B2.

  The cathode frame portion 72 has a first region 721 that becomes the cathode terminal portion 41 and a second region 722 that becomes the extending portion 42. In the cathode frame portion 72, the first region 721 and the second region 722 are arranged in this order in the predetermined direction Da, and are provided so that the second region 722 is disposed at a position closest to the anode frame portion 71. Yes.

  In the frame processing process, a first bending process, a second bending process, and a crushing process are performed. The first and second bending steps are steps for forming the anode lead structure 3 and are performed on the anode frame portion 71 in this order. The crushing process is a process for forming the cathode lead structure 4 and is performed on the cathode frame portion 72.

  FIG. 4A is a cross-sectional view used for explaining the first bending process. As shown in FIG. 4A, in the first bending step, the fourth region 714 is the first region when the first region 711 and the third region 713 are opposed to each other in the next second bending step. The anode frame portion 71 is bent at the edge 713a of the third region 713 so that the region 711 is arranged substantially perpendicularly to the region 711 (see FIG. 4B), whereby the posture of the fourth region 714 is changed. Change. Specifically, the anode frame portion 71 is bent so that the tip 714a of the fourth region 714 faces downward and the fourth region 714 is substantially perpendicular to the third region 713. In the first bending process, the anode frame portion 71 may be bent so that the fourth region 714 is inclined with respect to the third region 713. In this case, when the first region 711 and the third region 713 are opposed to each other in the second bending process, the fourth region 714 is disposed to be inclined with respect to the first region 711.

  FIG. 4B is a cross-sectional view used for explaining the second bending process. As shown in FIG. 4B, in the second bending step, the second region 712 is bent so that the third region 713 faces the first region 711, and the first region 711, the third region 713, A gap Rg is formed between the two. Specifically, the third region 713 is arranged above the first region 711 by curving the second region 712 in a U shape with reference to the one-dot chain line B3 shown in FIG. The anode frame portion 71 is folded back. Note that the second region 712 is not limited to the U-shape, and may be bent into various shapes such as a V-shape. Further, instead of bending the second region 712, the anode frame portion 71 is bent at the edge 712a of the second region 712 and the edge 711a of the first region 711 (matching the other edge of the second region 712). May be.

  In the second bending process, the gap Rg may be formed so as not to be cut halfway from the edge 712a of the second region 712 to the edge 713a of the third region 713. The third region 713 may be partially brought into contact. In addition, the second bending process may be performed before the first bending process or may be performed simultaneously with the first bending process.

  The anode lead structure 3 is formed by the first and second bending processes. That is, the first region 711 becomes the anode terminal portion 31, the second region 712 becomes the connecting portion 33, the third region 713 becomes the facing portion 32, and the fourth region 714 becomes the connecting portion 34. And the opening part 35 leads to the clearance gap Rg provided between the 1st area | region 711 (anode terminal part 31) and the 3rd area | region 713 (opposing part 32).

  FIG.4 (c) is sectional drawing used for description of a crushing process. As shown in FIG. 4C, in the crushing process, the second region 722 is crushed so that the thickness T2 of the second region 722 is smaller than the thickness T1 of the first region 721. . Specifically, the second region 722 is crushed so that the position of the lower surface 722a of the second region 722 is shifted upward from the position of the lower surface 721a of the first region 721. Thereby, the cathode lead structure 4 is formed. That is, the first region 721 becomes the cathode terminal portion 41, and the second region 722 becomes the extension portion 42.

  In the present embodiment, the anode lead structure 3 and the cathode lead structure 4 are in the following state by the frame preparation process and the frame processing process described above. That is, the lower surface 31 a of the anode terminal portion 31 and the lower surface 41 a of the cathode terminal portion 41 are aligned on substantially the same plane, and the connecting portion 33 and the opening portion 35 face the cathode terminal portion 41. The anode lead structure 3 and the cathode lead structure 4 are manufactured separately by separating the anode frame portion 71 and the cathode frame portion 72 from the frame 7 in the frame preparation step or the frame processing step. Also good. In this case, before the next connecting step, the anode lead structure 3 and the cathode lead structure 4 are arranged such that the lower surface 31a of the anode terminal portion 31 and the lower surface 41a of the cathode terminal portion 41 are aligned on substantially the same plane, 33 and the opening 35 are arranged so as to face the cathode terminal portion 41.

  FIG. 5 is a cross-sectional view used for explaining the connection process. As shown in FIG. 5, in the connection step, the capacitor element 1 is connected to the anode lead structure 3 and the cathode lead structure 4. Specifically, the anode lead structure 3 and the cathode are arranged such that the anode lead 12 faces the connecting portion 34 (fourth region 714) and the cathode layer 15 faces the extending portion 42 (second region 722). The capacitor element 1 is arranged with respect to the drawer structure 4. Then, the anode lead 12 is electrically and mechanically connected to the tip 34a of the connection portion 34 by connection means such as welding. Further, the cathode layer 15 and the extending portion 42 are electrically and mechanically connected to each other by interposing the conductive adhesive 6 between them. Note that the conductive adhesive 6 is preferably interposed between the cathode layer 15 and the cathode terminal portion 41 as shown in FIG.

  FIG. 6 is a cross-sectional view used for explaining the resin molding process. In the resin molding step, first, the capacitor element 1, the anode lead structure 3, and the cathode lead structure 4 are disposed in the mold 5. At this time, the lower surface 31 a of the anode terminal portion 31 and the lower surface 41 a of the cathode terminal portion 41 are brought into surface contact with the bottom surface 5 a in the mold 5. Therefore, as in the conventional solid electrolytic capacitor (see FIG. 8), the mold 5 is narrowly sandwiched between the capacitor element 1 and the mold 5 between the anode terminal portion 31 and the cathode terminal portion 41. A space Rc is formed.

  Next, the softened resin is poured into the mold 5 from either one of the grooves 5 b and 5 c provided in the mold 5. At this time, the other groove may be closed or used as a resin outlet. As the resin, a thermosetting resin such as an epoxy resin is used. The resin poured into the mold 5 tries to flow into the space Rc with the gap provided between the capacitor element 1 and the anode lead structure 3 as a main inlet Re (the white area shown in FIG. 6). (See arrow Fc). The resin is not limited to a thermosetting resin, and various resins that can be cured from a softened state can be used.

  Here, according to the manufacturing method of the present embodiment, in the mold 5, the gap Rg provided between the anode terminal portion 31 and the facing portion 32 in the frame processing step is a space through the opening 35. It leads to Rc. That is, a passage different from the passage passing through the inlet Re is formed by the opening 35 and the gap Rg as a passage leading to the space Rc.

  Therefore, when the resin flows into the mold 5 and the resin tries to enter the space Rc, the air in the space Rc easily escapes to the outside through the opening 35 and the gap Rg (the solid line shown in FIG. 6). (See arrow Fa). That is, the passage formed by the opening 35 and the gap Rg functions as a pressure relief passage. As a result, the resin easily flows into the space Rc, and the pressure of the resin hardly increases in the vicinity of the inlet Re of the space Rc. Therefore, the resin is sufficiently filled in the space Rc, and as a result, the resin easily reaches the entire mold 5. Note that, according to the manufacturing method of the present embodiment, the resin may flow into the space Rc through the opening 35 and the gap Rg. In this case, the air in the space Rc escapes from the inlet Re to the outside.

  After the mold 5 is filled with resin, the resin in the mold 5 is cured. In addition, when resin is a thermosetting resin, hardening of resin is accelerated | stimulated by heating the resin in the metal mold | die 5. FIG. In this way, the exterior body 2 is formed. Thereafter, the mold 5 is removed, and the anode terminal portion 31 and the cathode terminal portion 41 are cut along the alternate long and short dash lines B4 and B5 shown in FIG. Thereby, the solid electrolytic capacitor shown in FIG. 1 is completed.

  According to the manufacturing method of the present embodiment, as described above, the resin easily spreads throughout the mold 5. Accordingly, in the formed exterior body 2, it is difficult to generate a void without resin. Further, since the resin pressure is difficult to increase in the mold 5, it is difficult for stress to occur in the capacitor element 1, and thus defects such as cracks are not easily generated in the dielectric layer 13. As a result, an increase in leakage current is suppressed in the manufactured solid electrolytic capacitor. Further, stress is not easily generated at the connection portion between the anode lead 12 and the connection portion 34. Therefore, in a manufactured solid electrolytic capacitor, poor electrical connection (for example, breakage of welding) hardly occurs.

  Furthermore, according to the manufacturing method of the present embodiment, the opening 35 and the gap Rg are also filled with resin. Therefore, in the manufactured solid electrolytic capacitor, the resin filling the opening 35 and the gap Rg and the resin filling the space Rc are connected. Therefore, the peeling of the resin from the manufactured solid electrolytic capacitor (particularly, the peeling of the portion constituting the lower surface 2a of the exterior body 2) is prevented by the anchor effect. In the present embodiment, the opening 35 extends along the edge 31 c of the anode terminal portion 31 or the first edge 32 a of the facing portion 32. Therefore, the connection between the resin that fills the opening 35 and the gap Rg and the resin that fills the space Rc is strong, and thus the anchor effect is easily exhibited.

  In addition, each part structure of this invention is not restricted to the said embodiment, A various deformation | transformation is possible within the technical scope as described in a claim. For example, the opening 35 is not limited to a flat shape, and may have various shapes such as a circle and a rectangle. The present invention is not limited to lead type solid electrolytic capacitors, but can be applied to various types of solid electrolytic capacitors in which an outer package is formed by a resin mold.

DESCRIPTION OF SYMBOLS 1 Capacitor element 2 Exterior body 2a Lower surface 3 Anode extraction structure 4 Cathode extraction structure 5 Mold 5a Bottom surface 5b, 5c Groove 6 Conductive adhesive 7 Frame 11 Anode body 12 Anode lead 13 Dielectric layer 14 Electrolyte layer 15 Cathode layer 31 Anode terminal portion 31a Lower surface 31b Upper surface 31c Edge 32 Opposing portion 32a First edge 32b Second edge 33 Connection portion 34 Connection portion 34a Tip 35 Opening portion 41 Cathode terminal portion 41a Lower surface 41b Upper surface 41c Edge 42 Extending portion 42a lower surface 42b upper surface 71 anode frame portion 72 cathode frame portions 71a, 72a lower surface B1, B2 boundary lines B3, B4, B5 alternate long and short dash line Da predetermined direction Fa solid line arrow Fc white arrow Rc space Re inlet Rg gap 711 first region 711a end Edge 712 Second area 712a End edge 713 Third area 713a End edge 714 Fourth area 714a Tip 721 1st field 722 2nd field 721a and 722a Bottom

Claims (4)

A capacitor element having an anode member, a cathode member, and a dielectric member;
An exterior body covering the capacitor element;
An anode lead structure that has an anode terminal portion exposed on a lower surface of the exterior body and is electrically connected to the anode member;
A cathode lead structure exposed on the lower surface of the exterior body, and a cathode lead structure electrically connected to the cathode member;
The anode drawer structure is
A facing portion facing the upper surface of the anode terminal portion;
A connecting portion for connecting the edge of the anode terminal portion located on the cathode terminal portion side and the first edge of the facing portion to each other;
A connection portion connected to the second end of the facing portion opposite to the first end edge and electrically connected to the anode member;
A gap is provided between the upper surface of the anode terminal portion and the facing portion,
The connecting portion is provided with an opening leading to the gap,
A solid electrolytic capacitor in which the opening and the gap are filled with a part of a resin constituting the exterior body.   The solid electrolytic capacitor according to claim 1, wherein the opening extends along the edge of the anode terminal portion or the first edge of the facing portion. A capacitor element having an anode member, a cathode member, and a dielectric member, an exterior body covering the capacitor element, an anode terminal portion exposed on a lower surface of the exterior body, and electrically connected to the anode member A method for producing a solid electrolytic capacitor comprising: an anode lead structure; and a cathode lead structure having a cathode terminal portion exposed on a lower surface of the exterior body and electrically connected to the cathode member,
(A) A flat frame having an upper surface and a lower surface, which serves as the anode lead structure, the first region serving as the anode terminal portion, and a region in contact with the edge of the first region and connected A second region that is a part, a third region that is in contact with an edge of the second region opposite to the first region and that is an opposing part, and the second region that is opposite to the second region A frame having a fourth region serving as a connection portion and in contact with an edge of the third region; and an opening formed in the second region and penetrating the frame from the upper surface to the lower surface. A preparation process;
(B) Bending the second region, or bending the frame at the edge of the first region and the edge of the second region, thereby causing the third region to face the first region. A gap is formed between the first region and the third region, and the frame is bent at the edge of the third region, thereby changing the posture of the fourth region, the anode terminal portion, Forming the anode drawer structure having the connecting portion, the facing portion, and the connecting portion;
(C) After the step (b), in the state where the connecting portion and the opening portion are directed toward the cathode terminal portion, the anode member is electrically connected to the connection portion, and the cathode terminal portion Electrically connecting the cathode member to the upper surface of
(D) After the step (c), the outer body is formed by resin molding using a mold, and the lower surface of the anode terminal portion and the lower surface of the cathode terminal portion are on the inner surface of the mold. Placing the capacitor element, the anode lead structure, and the cathode lead structure in a mold so that they come into contact with each other, and then pouring a resin into the mold. Method.   4. The manufacturing of the solid electrolytic capacitor according to claim 3, wherein, in the step (a), the opening has a flat shape extending along a boundary line between the two regions and the first or third region. Method.

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