Solid electrolytic capacitor and method of manufacturing same

Abstract

The solid electrolytic capacitor includes a capacitor element having an anode foil with a porous portion on the surface of a substrate, a dielectric layer formed on at least a portion of the surface of the anode foil, a solid electrolyte layer covering at least a portion of the dielectric layer, and a cathode extraction layer covering at least a portion of the solid electrolyte layer. The anode foil has an anode portion where the solid electrolyte layer is not formed, a cathode formation portion where the solid electrolyte layer is formed, and a separator between the anode portion and the cathode formation portion. A first insulating material is disposed on the surface of the porous portion in the separator, and at least a portion of the region of the porous portion covered by the first insulating material contains a second insulating material.

Description

[Technical field]

[0001] The present disclosure relates to a solid electrolytic capacitor and a method for manufacturing the same. [Background technology]

[0002] The solid electrolytic capacitor includes a capacitor element having a solid electrolyte layer, an electrode terminal electrically connected to the capacitor element, and an exterior body sealing the capacitor element. The capacitor element includes, for example, an anode foil having a porous portion on its surface, a dielectric layer formed on at least a portion of the surface of the anode foil, a solid electrolyte layer covering at least a portion of the dielectric layer, and a cathode lead layer covering at least a portion of the solid electrolyte layer.

[0003] Patent Document 1 proposes a solid electrolytic capacitor that includes a plurality of capacitor elements each of which is made up of an anode portion made of a valve action metal with an oxide film layer formed on its surface, a cathode portion formed in a layered shape having a solid electrolyte layer in a predetermined region of the surface and with the outermost layer made of a conductive material, and a resist portion that electrically insulates the anode portion from the cathode portion.

[0004] Patent Document 2 proposes a solid electrolytic capacitor having a shielding layer in a region separating an anode region and a cathode region of a solid electrolytic capacitor substrate having a porous layer on the surface.

[0005] Patent Document 3 proposes a method for manufacturing a solid electrolytic capacitor, which includes a step of applying a masking material solution that permeates into a dielectric film and forms a masking layer on the permeated portion.

[0006] Patent Document 4 proposes providing an etching layer formed on the surface of a valve metal with a resist layer that prevents penetration of a solid electrolyte material, thereby separating an anode portion from a cathode portion, forming a first groove on the cathode portion side of the resist layer, and forming a second groove closer to the anode portion side than the first groove and forming a resist layer in the second groove. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2007-165777 A [Patent Document 2] International Publication No. 2007 / 061005 Brochure [Patent Document 3] International Publication No. 2000 / 067267 Brochure [Patent Document 4] JP 2007-305661 A Summary of the Invention [Problem to be solved by the invention]

[0008] In solid electrolytic capacitors, air can enter the inside through the porous part of the anode foil connected to the electrode terminal. When oxygen in the air comes into contact with the solid electrolyte layer in the capacitor element, the conductive polymer in the solid electrolyte layer deteriorates under high temperatures, causing the capacitance of the solid electrolytic capacitor to decrease. [Means for solving the problem]

[0009] A first aspect of the present disclosure is The substrate and the a capacitor element including an anode foil having a porous portion on a surface of a base portion, a dielectric layer formed on at least a portion of a surface of the anode foil, a solid electrolyte layer covering at least a portion of the dielectric layer, and a cathode lead layer covering at least a portion of the solid electrolyte layer, the anode foil has an anode portion on which the solid electrolyte layer is not formed, a cathode forming portion on which the solid electrolyte layer is formed, and a separation portion between the anode portion and the cathode forming portion, a first insulating material is disposed on a surface of the porous portion in the separation portion; The present invention relates to a solid electrolytic capacitor, wherein at least a part of a region of the porous portion that is covered with the first insulating material contains a second insulating material.

[0010] A second aspect of the present disclosure is The substrate and thea capacitor element including an anode foil having a porous portion on a surface of a base portion, a dielectric layer formed on a surface of the anode foil, a solid electrolyte layer covering at least a portion of the dielectric layer, and a cathode lead layer covering at least a portion of the solid electrolyte layer, the anode foil has an anode portion on which the solid electrolyte layer is not formed, a cathode forming portion on which the solid electrolyte layer is formed, and a separation portion between the anode portion and the cathode forming portion, A first insulating material is disposed or included in at least a portion of the separation portion; The capacitor element relates to a solid electrolytic capacitor, further comprising a second insulating material in at least a part of a region of the separator closer to the anode portion than the first insulating material.

[0011] A third aspect of the present disclosure is The substrate and the a capacitor element including an anode foil having a porous portion on a surface of a base portion, a dielectric layer formed on a surface of the anode foil, a solid electrolyte layer covering at least a portion of the dielectric layer, and a cathode lead layer covering at least a portion of the solid electrolyte layer, the anode foil has an anode portion on which the solid electrolyte layer is not formed, a cathode forming portion on which the solid electrolyte layer is formed, and a separation portion between the anode portion and the cathode forming portion, A first insulating material is disposed or included in at least a portion of the separation portion; The present invention relates to a solid electrolytic capacitor, wherein at least a part of a region of the separator closer to the cathode formation portion than the first insulating material is covered with the solid electrolyte layer.

[0012] A fourth aspect of the present disclosure is The substrate and the a capacitor element including an anode foil having a porous portion on a surface of a base portion, a dielectric layer formed on a surface of the anode foil, a solid electrolyte layer covering at least a portion of the dielectric layer, and a cathode lead layer covering at least a portion of the solid electrolyte layer, the anode foil has an anode portion on which the solid electrolyte layer is not formed, a cathode forming portion on which the solid electrolyte layer is formed, and a separation portion between the anode portion and the cathode forming portion, A first insulating material is disposed or included in at least a portion of the separation portion; adjacent to the first insulating material on the cathode forming portion side of the separator do A second groove portion is formed, The present invention relates to a solid electrolytic capacitor, wherein the solid electrolyte layer is disposed in at least a partial region of the second groove portion.

[0013] A fifth aspect of the present disclosure is The substrate and the a capacitor element including an anode foil having a porous portion on a surface of a base portion, a dielectric layer formed on a surface of the anode foil, a solid electrolyte layer covering at least a portion of the dielectric layer, and a cathode lead layer covering at least a portion of the solid electrolyte layer, the anode foil has an anode portion on which the solid electrolyte layer is not formed, a cathode forming portion on which the solid electrolyte layer is formed, and a separation portion between the anode portion and the cathode forming portion, A first insulating material is disposed or included in at least a portion of the separation portion; a third groove portion is formed in at least a part of the cathode formation portion, The present invention relates to a solid electrolytic capacitor, wherein the solid electrolyte layer is disposed in at least a partial region of the third groove portion.

[0014] A sixth aspect of the present disclosure is The substrate and the a capacitor element including an anode foil having a porous portion on a surface of a base portion, a dielectric layer formed on a surface of the anode foil, a solid electrolyte layer covering at least a portion of the dielectric layer, and a cathode lead layer covering at least a portion of the solid electrolyte layer, the anode foil has an anode portion on which the solid electrolyte layer is not formed, a cathode forming portion on which the solid electrolyte layer is formed, and a separation portion between the anode portion and the cathode forming portion, A first insulating material is disposed or included in at least a portion of the separation portion; adjacent to the first insulating material on the cathode forming portion side of the separator do A second groove portion is formed, The present invention relates to a solid electrolytic capacitor, in which a second insulating material is disposed in at least a partial region of the second groove portion.

[0015] A seventh aspect of the present disclosure is (i) The substrate and the A step of forming a dielectric layer on at least a part of the surface of an anode foil having a porous portion on the surface of a base portion; (ii) dividing the anode foil on which the dielectric layer is formed into an anode portion, a cathode-forming portion, and a separation portion between the anode portion and the cathode-forming portion, and compressing or partially removing the porous portion in the separation portion; (iii) disposing a first insulating material on a surface of the separator; (iv) covering at least a portion of the dielectric layer in the cathode formation portion with a solid electrolyte layer; (v) covering at least a portion of the solid electrolyte layer with a cathode extraction layer; and (vi) after step (v), in at least a part of the region of the separating portion that is covered with the first insulating material, To the department and a step of impregnating the solid electrolytic capacitor with a second insulating material.

[0016] An eighth aspect of the present disclosure is (i) The substrate and the A step of forming a dielectric layer on at least a part of the surface of an anode foil having a porous portion on the surface of a base portion; (ii) The anode foil on which the dielectric layer is formed is placed in an anode portion, a cathode forming portion, and a formation and a separation section between the porous sections, and at least a part of the porous section of the separation section of Compression and and removal Leaving Do at least one of the following: process, (iii) disposing or impregnating at least a portion of the separator with a first insulating material; (iv) covering at least a portion of the dielectric layer in the cathode formation portion with a solid electrolyte layer; (v) covering at least a portion of the solid electrolyte layer with a cathode extraction layer; and (vi) after step (v), a step of disposing or impregnating a second insulating material in at least a part of a region of the separation portion closer to the anode portion than the first insulating material is. Effect of the Invention

[0017] To suppress the decrease in capacitance of a solid electrolytic capacitor after exposure to high temperatures. [Brief description of the drawings]

[0018] [Figure 1] 1 is a cross-sectional view illustrating a schematic diagram of a solid electrolytic capacitor according to a first embodiment of the present disclosure. [Diagram 2] 2 is a cross-sectional view that illustrates a schematic diagram of a capacitor element included in the solid electrolytic capacitor of FIG. [Diagram 3] 4 is a cross-sectional view illustrating a schematic diagram of a capacitor element included in a solid electrolytic capacitor according to a second embodiment of the present disclosure. FIG. [Figure 4] FIG. 11 is a cross-sectional view illustrating a schematic diagram of a capacitor element included in a solid electrolytic capacitor according to a third embodiment of the present disclosure. [Diagram 5] FIG. 11 is a cross-sectional view illustrating a schematic diagram of a capacitor element included in a solid electrolytic capacitor according to a fourth embodiment of the present disclosure. [Figure 6] FIG. 13 is a cross-sectional view illustrating a schematic diagram of a capacitor element included in a solid electrolytic capacitor according to a fifth embodiment of the present disclosure. [Figure 7] FIG. 13 is a cross-sectional view illustrating a schematic diagram of a capacitor element included in a solid electrolytic capacitor according to a sixth embodiment of the present disclosure. [Figure 8] FIG. 13 is a cross-sectional view illustrating a schematic diagram of a capacitor element included in a solid electrolytic capacitor according to a seventh embodiment of the present disclosure. [Figure 9] FIG. 13 is a cross-sectional view illustrating a schematic diagram of a capacitor element included in a solid electrolytic capacitor according to an eighth embodiment of the present disclosure. [Figure 10] FIG. 13 is a cross-sectional view illustrating a schematic diagram of a capacitor element included in a solid electrolytic capacitor according to a ninth embodiment of the present disclosure. [Figure 11] FIG. 13 is a cross-sectional view illustrating a schematic diagram of a capacitor element included in a solid electrolytic capacitor according to a tenth embodiment of the present disclosure. [Figure 12]FIG. 14 is a cross-sectional view illustrating a schematic diagram of a capacitor element included in a solid electrolytic capacitor according to an eleventh embodiment of the present disclosure. [Figure 13] FIG. 23 is a cross-sectional view illustrating a schematic diagram of a capacitor element included in a solid electrolytic capacitor according to a twelfth embodiment of the present disclosure. [Figure 14] FIG. 23 is a cross-sectional view illustrating a schematic diagram of a capacitor element included in a solid electrolytic capacitor according to a thirteenth embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] The novel features of the present disclosure are set forth in the appended claims, but the present disclosure, both in terms of structure and content, together with other objects and features of the present disclosure, will be better understood from the following detailed description taken in conjunction with the drawings.

[0020] The anode foil of the capacitor element has a porous portion provided on the surface of the substrate. The porous portion contains many voids. The anode portion of the anode foil, where the solid electrolyte layer is not formed, is connected to an electrode terminal, and air may enter the capacitor element from the electrode terminal side through the voids in the porous portion, causing deterioration of the conductive polymer contained in the solid electrolyte layer. Such deterioration of the conductive polymer is particularly noticeable in high temperature environments.

[0021] In a solid electrolytic capacitor according to a first aspect of the present disclosure, a separation portion is provided between the anode portion and the cathode forming portion of an anode foil of a capacitor element, and a first insulating material is disposed on the surface of a porous portion of this separation portion. In the separation portion, the region where the first insulating material is disposed is referred to as a first region, the region between the first insulating material (or first region) and the cathode forming portion is referred to as a second region, and the region on the anode portion side of the first insulating material (or first region) is referred to as a third region. In the above solid electrolytic capacitor, , many The porous portion is covered with a first insulating material. No. 1 At least a portion of the region includes the second insulating material. When the porous portion of the first region includes the second insulating material, infiltration of air from the first region into the capacitor element is suppressed.

[0022] The solid electrolytic capacitor according to the above aspect can be formed by forming a capacitor element having a first insulating material disposed on the surface of a separator, and then impregnating the voids in the porous portion of the first region with a second insulating material. From the viewpoint of enhancing the effect of suppressing air intrusion, the porous portion of the first region (more specifically, the voids in the porous portion) may be filled with the second insulating material.

[0023] A solid electrolytic capacitor according to a second aspect of the present disclosure has a separator between an anode portion and a cathode forming portion of an anode foil of a capacitor element. A first insulating material is disposed or included in at least a portion of the separator. The capacitor element includes a second insulating material in at least a portion of a region (third region) of the separator that is closer to the anode portion than the first insulating material. This prevents air from entering the capacitor element from the anode portion side.

[0024] The solid electrolytic capacitor according to the second aspect can be manufactured by compressing and / or removing at least a portion of the porous portion of the separator, disposing or impregnating at least a portion of the separator with a first insulating material, forming a solid electrolyte layer and a cathode extraction layer, and then disposing or impregnating at least a portion of the separator with a second insulating material. The second insulating material is disposed or impregnated in at least a portion of the third region.

[0025] In a solid electrolytic capacitor according to a third aspect of the present disclosure, a first insulating material is disposed or included in at least a portion of the separator, and at least a portion of a region of the separator closer to the cathode-forming portion than the first insulating material (or first region) (i.e., a second region of the separator) is covered with a solid electrolyte layer. Also, in a solid electrolytic capacitor according to a fourth aspect of the present disclosure, a first insulating material is disposed or included in at least a portion of the separator, and a solid electrolyte layer is disposed adjacent to the first insulating material on the cathode-forming portion side of the separator. doA second groove is formed, and a solid electrolyte layer is disposed in at least a portion of the second groove. The second groove is formed in the second region. In these solid electrolytic capacitors, the solid electrolyte layer is disposed in at least a portion of the second region, so that air intrusion from the second region is suppressed. From the viewpoint of enhancing the effect of suppressing air intrusion, the second groove may be filled with the solid electrolyte layer.

[0026] In a solid electrolytic capacitor according to a fifth aspect of the present disclosure, a first insulating material is disposed or included in at least a part of the separator, a third groove is formed in at least a part of the cathode forming part, and a solid electrolyte layer is disposed in at least a part of the third groove. In such a solid electrolytic capacitor, air intrusion from a region closer to the anode part than the third groove is suppressed. From the viewpoint of enhancing the effect of suppressing air intrusion, the third groove may be filled with the solid electrolyte layer.

[0027] In the solid electrolytic capacitor according to the sixth aspect of the present disclosure, a first insulating material is disposed or included in at least a part of the separator, and a first insulating material is disposed adjacent to the first insulating material on the cathode forming portion side of the separator. do A second groove is formed, and a second insulating material is disposed in at least a portion of the second groove. The second groove is formed in the second region. In such a solid electrolytic capacitor, the second insulating material is disposed in at least a portion of the second region, so that air intrusion from the second region is suppressed. From the viewpoint of enhancing the effect of suppressing air intrusion, the second groove may be filled with the second insulating material.

[0028] In this way, in the solid electrolytic capacitor of these aspects, the intrusion of air into the capacitor element is suppressed. This enhances the effect of suppressing the deterioration of the conductive polymer contained in the solid electrolyte layer even after the solid electrolytic capacitor is exposed to high temperatures. This makes it possible to suppress the decrease in capacitance after a heat resistance test. In addition, the improved heat resistance of the solid electrolyte layer allows: After heat resistance test ESR (equivalent series resistance) and dielectric tangent (tan δ) Rise of can be reduced.

[0029] The term "insulating material is contained in a porous portion, a separating portion, or a capacitor element" is used in a broad sense to include the case where the insulating material is contained in the porous portion, the separating portion, or the capacitor element (more specifically, in the gaps therein) in a state of being impregnated or filled.

[0030] Hereinafter, the solid electrolytic capacitor and the manufacturing method thereof according to the above aspects of the present disclosure will be described in more detail with reference to the drawings as necessary.

[0031] [Solid electrolytic capacitor] (Capacitor element) The capacitor element of the solid electrolytic capacitor includes an anode foil, a dielectric layer formed on at least a portion of the surface of the anode foil, a solid electrolyte layer covering at least a portion of the dielectric layer, and a cathode lead layer covering at least a portion of the solid electrolyte layer. A substrate portion, The substrate has a porous portion on its surface. The anode foil is divided into a cathode forming portion where a solid electrolyte layer is formed, an anode portion where a solid electrolyte layer is not formed, and a separation portion between the anode portion and the cathode forming portion. The separation portion may have, for example, a portion where the porous portion has a small thickness (thin portion). The thin portion is formed by compressing or partially removing the porous portion. The compressed portion of the porous portion may be referred to as a compressed portion. The recess formed in the separation portion by compressing and / or removing the porous portion may be referred to as a groove portion. The groove portion may be formed on the substrate via a porous portion, or may be formed directly on the substrate without a porous portion. The portion where the groove portion is formed (or the thin portion) has fewer air passages than the other portions, so it is advantageous to provide the groove portion from the viewpoint of suppressing air intrusion.

[0032] Fig. 1 is a cross-sectional view showing a schematic structure of a solid electrolytic capacitor according to a first embodiment of the present disclosure, Fig. 2 is an enlarged cross-sectional view showing a schematic structure of a capacitor element 2 included in the solid electrolytic capacitor of Fig. 1.

[0033] Solid electrolytic capacitor 1 includes a capacitor element 2, an exterior housing 3 that seals capacitor element 2, and an anode lead terminal 4 and a cathode lead terminal 5, at least a portion of which is exposed to the outside of exterior housing 3. Exterior housing 3 has an approximately rectangular parallelepiped outer shape, and solid electrolytic capacitor 1 also has an approximately rectangular parallelepiped outer shape.

[0034] Capacitor element 2 includes an anode foil 6, a dielectric layer (not shown) covering the surface of anode foil 6, and a cathode portion 8 covering the dielectric layer. The dielectric layer may be formed on at least a portion of the surface of anode foil 6.

[0035] The cathode unit 8 includes a solid electrolyte layer 9 and a cathode extraction layer 10. The solid electrolyte layer 9 is formed so as to cover at least a portion of the dielectric layer. The cathode extraction layer 10 is formed so as to cover at least a portion of the solid electrolyte layer 9. The cathode extraction layer 10 includes a carbon layer 11 and a metal paste layer 12. The cathode lead terminal 5 is electrically connected to the cathode unit 8 via an adhesive layer 14 formed of a conductive adhesive.

[0036] The anode foil 6 includes a substrate portion 6a and a porous portion 6b formed on the surface of the substrate portion 6a. The anode foil 6 includes an anode portion 16a where the solid electrolyte layer 9 is not formed, a cathode forming portion 16b where the solid electrolyte layer 9 (or the cathode portion 8) is formed, and a separation portion 16c between the anode portion 16a and the cathode forming portion 16b. The anode lead terminal 4 is electrically connected to the anode portion 16a of the anode foil 6 by welding.

[0037] A first insulating material 13 is disposed on the surface of the porous portion 6b in the separation portion 16c. The first insulating material 13 prevents the conductive polymer from creeping up toward the anode portion 16a when forming the solid electrolyte layer 9, and prevents the conductive polymer from creeping up toward the anode portion 16a and the cathode portion 8. (Electrical) In the illustrated example, the separation portion 16c has a thin portion 26, and the first insulating material 13 is disposed in the thin portion 26. The first insulating material 13 may be disposed in at least a part of the thin portion 26. However, the separation portion 16c does not have to have the thin portion 26.

[0038] In this embodiment, at least a part of the area of ​​the porous portion 6b in the first region 36a covered with the first insulating material 13 contains the second insulating material 7. More specifically, the porous portion 6b in the first region 36a contains the second insulating material 7. The porous portion 6b contains voids. Therefore, the porous portion 6b contains the second insulating material 7 impregnated in the voids. Since the porous portion 6b in the first region 36a contains the second insulating material 7, the intrusion of air into the capacitor element through the first region 36a is suppressed. This suppresses deterioration of the conductive polymer contained in the solid electrolyte layer 9 due to oxygen, and therefore the heat resistance of the solid electrolyte layer 9 can be improved. The decrease in the capacitance of the solid electrolytic capacitor after a heat resistance test can be suppressed. In addition, After heat resistance test ESR and dissipation factor Rise of can be reduced.

[0039] It is sufficient that the second insulating material 7 is contained at least in the porous portion 6b of the first region 36a. The second insulating material 7 may further be contained at least in the periphery of the first region 36a. In this case, air is prevented from entering the capacitor element 2 through the porous portion 6b in the periphery of the first region 36a. The second insulating material 7 may also be contained in at least a part of the cathode extraction layer 10. This makes it possible to prevent air from entering the capacitor element 2 from the cathode extraction layer 10.

[0040] For example, the second insulating material 7 may be contained in the porous portion 6b between the first insulating material 13 and the cathode extraction layer 10 (in other words, the porous portion 6b in the second region 36b between the first insulating material 13 and the cathode extraction layer 10 of the porous portion 6b). The second insulating material 7 may be contained in the porous portion 6b closer to the anode portion 16a than the first insulating material 13 (in other words, the porous portion 6b in the third region 36c closer to the anode portion 16a than the first insulating material 13 of the porous portion 6b). In this case, the portion containing the second insulating material 7 may be the porous portion 6b in either the anode portion 16a or the separation portion 16c, depending on the position of the first insulating material 13.

[0041] The second insulating material 7 may be contained in these positions in an impregnated state or in a filled state.

[0042] FIG. 3 is a cross-sectional view that shows a schematic diagram of a capacitor element 2 included in the solid electrolytic capacitor according to the second embodiment. The cathode portion 8 of the capacitor element 2 has a plurality of layers and has a certain degree of thickness, so that a recess (neck) is formed between the cathode portion 8 and the separating portion 16c (or the first insulating material 13). As shown in FIG. 3, the surface of this recess (neck) may be covered with the third insulating material 17. It is sufficient that at least a part of the surface of the recess is covered with the third insulating material 17, and the recess may be filled with the third insulating material 17. The third insulating material 17 may be attached to at least the periphery of the first region 36a. The third insulating material 17 may cover at least a part of at least one of the cathode extraction layer 10 and the solid electrolyte layer 9. For example, as shown in FIG. 3, the end of the cathode extraction layer 10 or the solid electrolyte layer 9 on the anode portion 16a side and its periphery may be covered with the third insulating material 17. The third insulating material 17 may cover at least a part of the surface of the solid electrolyte layer 9 that is not covered by the cathode extraction layer 10. For example, at the end of the cathode extraction layer 10 on the anode portion 16a side, there may be a part of the solid electrolyte layer 9 that is not covered by the cathode extraction layer 10. In such a case, at least a part of the solid electrolyte layer 9 may be covered with the third insulating material 17 between the first insulating material 13 (or the first region 36a) and the end of the cathode extraction layer 10 on the anode portion 16a side. In the case of FIG. 3, the second insulating material is contained in the porous portion 6b of the first region 36a, the second region 36b, and the third region 36c, as in the cases of FIG. 1 and FIG. 2. Capacitor element 2 2 except that the recess (neck), the end of cathode extraction layer 10 and / or solid electrolyte layer 9 on the anode portion 16a side and at least a part of the periphery thereof are covered with third insulating material 17. Capacitor element 2 1 and 2. Although not shown, at least a portion of the porous portion 6b on the anode portion 16a side of the first insulating material 13 may be covered with the third insulating material 17.

[0043] FIG. 4 is an enlarged cross-sectional view that illustrates a schematic diagram of capacitor element 2 included in the solid electrolytic capacitor in accordance with the third embodiment. 4, the third insulating material 17 covers the surface of the first insulating material 13, the surface of the porous portion 6b between the first insulating material 13 and the end of the cathode extraction layer 10 on the anode portion 16a side, and the surface of the porous portion 6b on the anode portion 16a side of the first insulating material 13. The second insulating material is also contained in the porous portions 6b in the second region 36b and the third region 36c.

[0044] Metal paste layer 12 is not dense, and gaps exist within the layer. Therefore, when an insulating material is supplied to the surface of cathode extraction layer 10, metal paste layer 12 is impregnated with the insulating material. This impregnated insulating material corresponds to second insulating material 7. In FIG. 4, second insulating material 7 is contained in metal paste layer 12 in a state of being impregnated therein. However, second insulating material 7 does not necessarily need to be contained in metal paste layer 12 in its entirety, and it is sufficient that second insulating material 7 is contained in at least a part of metal paste layer 12. By containing the second insulating material in metal paste layer 12, it is possible to suppress the intrusion of air from metal paste layer 12 into capacitor element 2, and further suppress the deterioration of heat resistance of solid electrolyte layer 9. In addition, an insulating material may be attached to the surface of cathode extraction layer 10. The insulating material covering at least a part of cathode extraction layer 10 corresponds to third insulating material 17.

[0045] The second insulating material supplied from at least one of separation portion 16c, anode portion 16a, and cathode extraction layer 10 permeates into porous portion 6b, whereby porous portion 6b in at least one of first region 36a, second region 36b, third region 36c, and cathode formation portion 16b is impregnated or filled with the second insulating material. The second insulating material supplied to the surface of cathode extraction layer 10 may permeate into cathode extraction layer 10, solid electrolyte layer 9, etc., to impregnate or fill porous portion 6b in cathode formation portion 16b.

[0046] Fig. 5 is a cross-sectional view showing a schematic diagram of a capacitor element included in a solid electrolytic capacitor according to a fourth embodiment. In Fig. 5, three capacitor elements 102A, 102B, and 102C are laminated. For convenience, Fig. 5 shows only the laminated body of these capacitor elements. In Fig. 5, three capacitor elements are laminated, and Fig. 5 differs from Figs. 2 to 4 in that the areas covered with insulating material are different, but for other configurations, the explanations for Figs. 1 to 4 can be referred to.

[0047] 5, each of capacitor elements 102A, 102B, and 102C includes an anode foil 6, a dielectric layer covering the anode foil 6, a solid electrolyte layer 9 covering the dielectric layer, and a cathode extraction layer 10 covering the solid electrolyte layer 9, as in the case of FIG. 2. Anode foil 6 is divided into an anode portion 16a, a cathode forming portion 16b, and a separation portion 16c therebetween. A first insulating material 13 is disposed in porous portion 6b of separation portion 16c.

[0048] The fourth insulating material 117 covers a part of the surface of the laminate of the capacitor elements 102A, 102B, and 102C. More specifically, the fourth insulating material 117 covers a part of the surface of the first insulating material 13, the porous portion 6b between the first insulating material 13 and the end of the solid electrolyte layer 9 on the anode portion 16a side, and a part of the surface of the solid electrolyte layer 9. The fourth insulating material 117 may cover at least a part of the cathode extraction layer 10. The fourth insulating material 117 may cover at least a part of the laminate. Even in the case of a laminate of capacitor elements, by covering at least a part of the surface with the fourth insulating material 117, the intrusion of air into each capacitor element can be suppressed, and the deterioration of the heat resistance of the solid electrolyte layer 9 can be suppressed. In addition, after the laminate of the capacitor elements and the lead frame are connected, the fourth insulating material 117 may cover at least a part of the surface of the laminate and the lead frame. The position of the fourth insulating material 117 in the laminate is not limited to these cases. For example, in the laminate, at least one of the spaces between adjacent capacitor elements, the spaces between the first insulating materials 13 of adjacent capacitor elements, the spaces between the third insulating materials 17 of adjacent capacitor elements, and the entire surface of the laminate may be covered with a fourth insulating material 117.

[0049] In the laminate, at least a part of the cathode extraction layer 10 (for example, a silver paste layer) may contain a second insulating material. By supplying an insulating material to the surface of the laminate, the insulating material penetrates into the porous portion 6b, and the first region, the second region, and the porous portion 6b of the cathode formation portion 16b are also impregnated or filled with the insulating material. This impregnated or filled insulating material corresponds to the second insulating material. In the laminate, at least a part of the periphery of at least the first region 36a, the cathode extraction layer 10, the solid electrolyte layer 9, etc. may be covered with an insulating material (corresponding to a third insulating material).

[0050] The embodiments shown in the following Figs. 6 to 14 differ from Figs. 2 to 4 in that a groove is formed in the anode portion, the position of the insulating material, or the area covered by the solid electrolyte layer is different, but the explanation for Figs. 1 to 4 can be referred to for the other configurations. In these embodiments, the first insulating material 13 is disposed on the surface of the porous portion 6b (more specifically, the thin portion 26) as in Figs. 2 to 4, but is not limited to such a case. The first insulating material 13 may be disposed on at least a part of the separation portion 16c, or may be included in at least a part of the separation portion 16c. The first insulating material 13 may be disposed on at least a part of the thin portion 26. In addition, the separation portion 16c may not have the thin portion 26. The first insulating material 13 does not necessarily have to be disposed on the surface of the porous portion 6b, and may be disposed directly on the base portion 6a without the porous portion 6b. The capacitor element shown in these embodiments may be used as the capacitor element constituting the laminate of Fig. 5.

[0051] 6 is an enlarged cross-sectional view illustrating a schematic view of the capacitor element 2 included in the solid electrolytic capacitor according to the fifth embodiment. In this embodiment, in the separation portion 16c, the second insulating material 7 is included in at least a part of the third region 36c that is closer to the anode portion 16a than the first region 36a in which the first insulating material 13 is disposed. The inclusion of the second insulating material 7 in the third region 36c suppresses the intrusion of air into the capacitor element 2 from the anode portion 16a side. The second insulating material 7 may be disposed in the third region 36c, and the second insulating material 7 may be impregnated or filled in at least a part of the third region 36c.

[0052] In the illustrated example, a thin portion 26 is also formed in the third region 36c, thereby forming a groove portion (first groove portion) 19 adjacent to the first insulating material 13. The first groove portion 19 is filled with the second insulating material 7. By filling the first groove portion 19 with the second insulating material 7 in this manner, the intrusion of air into the capacitor element 2 through the porous portion 6b in the third region 36c is further suppressed.

[0053] The second insulating material 7 does not necessarily need to be filled so as to fill the entire first groove portion 19 as shown in FIG. 6, but it is sufficient that the second insulating material 7 is disposed in at least a partial region of the first groove portion 19. For example, the second insulating material 7 may be disposed so as to cover at least a partial region of the first groove portion 19. The first groove portion 19 may be impregnated with the second insulating material 7. For example, the second insulating material 7 may be filled so as to partially fill the first groove portion 19, or the second insulating material 7 may be disposed on at least a part of the inner surface of the first groove portion 19.

[0054] The second insulating material 7 may be contained in the porous portion 6b around the first groove portion 19 in a state of being impregnated (or filled). This can prevent air from entering the capacitor element 2 through the porous portion 6b around the first groove portion 19. For example, in the third region 36c, the porous portion 6b present below the first groove portion 19 may be contained in a state of being impregnated (or filled) with the second insulating material 7. The second insulating material 7 may be contained in at least a part of the porous portion 6b in the first region 36a (such as the part on the third region 36c side) in a state of being impregnated (or filled).

[0055] Second insulating material 7 may be contained in a state of being impregnated or filled into at least a portion of cathode extraction layer 10. Although not shown, at least a portion of cathode extraction layer 10 may be covered with third insulating material 17. In the case of at least one of these, it is possible to suppress the intrusion of air from cathode extraction layer 10 into capacitor element 2.

[0056] For example, the second insulating material 7 may be contained in a state of being impregnated or filled in the porous portion 6b between the first insulating material 13 and the cathode extraction layer 10 (in other words, the second region 36b between the first insulating material 13 and the cathode extraction layer 10 in the porous portion 6b). The second insulating material 7 may be contained in a state of being impregnated or filled in the porous portion 6b in a portion adjacent to the separation portion 16c of the anode portion 16a.

[0057] 6, as in the case of FIG. 3, the surface of the recess (neck) may be covered with third insulating material 17. Also, third insulating material 17 may be attached to at least the periphery of first region 36a. Third insulating material 17 may cover at least a portion of at least one of cathode extraction layer 10 and solid electrolyte layer 9. For the position of third insulating material 17, see the description of FIG. 3 or FIG. 4. At least a portion of the surface of first insulating material 13 may be covered with third insulating material 17.

[0058] FIG. 7 is a cross-sectional view that illustrates a schematic diagram of a capacitor element 2 included in a solid electrolytic capacitor in accordance with a sixth embodiment. In FIG. 7, the first groove 19 is formed by removing the porous portion 6b in the third region 36c. That is, there is no porous portion 6b below the first groove 19. However, other than this, it is the same as FIG. 6, and the explanations of FIG. 1 and FIG. 6 can be referred to. In the case of FIG. 7, as in the case of FIG. 6, the second insulating material 7 is filled in the first groove 19, thereby preventing air from entering. The second insulating material 7 may be contained in a state of being impregnated (or filled) in at least a part of the porous portion 6b in the first region 36a.

[0059] Fig. 8 is a cross-sectional view that shows a schematic of a capacitor element 2 included in the solid electrolytic capacitor according to the seventh embodiment. Fig. 9 is a cross-sectional view that shows a schematic of a capacitor element 2 included in the solid electrolytic capacitor according to the eighth embodiment. These figures show examples in which a porous portion 6b is present in a part below the first groove portion 19. These embodiments are the same as Fig. 6 except that the structure of the first groove portion 19 is different, and the explanations of Figs. 1 and 6 can be referred to.

[0060] In FIG. 8, in the portion of the third region 36c on the first region 36a side, there is a porous portion 6b below the first groove portion 19. In the remaining portion of the third region 36c on the anode portion 16a side, there is no porous portion 6b below the first groove portion 19. Due to the absence of the porous portion 6b, a recess is formed on the anode portion 16a side at the bottom of the first groove portion 19. The second insulating material 7 is filled in this recess, which can suppress the intrusion of air. The second insulating material may be impregnated (or filled) in the porous portion 6b below the first groove portion 19 in the portion of the third region 36c on the first region 36a side.

[0061] In FIG. 9, in the part of the third region 36c on the anode portion 16a side, the porous portion 6b is present under the first groove portion 19, and in the remaining part of the third region 36c on the first region 36a side, the porous portion 6b is not present under the first groove portion 19. At the bottom of the first groove portion 19, a recess is formed because the porous portion 6b is not present on the first region 36a side. In other words, the position of the porous portion 6b (or recess) under the first groove portion 19 is different from that in FIG. 8, and the rest is the same as FIG. 8. The recess on the first region 36a side is filled with the second insulating material 7, which can suppress the intrusion of air. The second insulating material 7 may be contained in a state of being impregnated (or filled) in the porous portion 6b under the first groove portion 19 in the part of the third region 36c on the anode portion 16a side.

[0062] In these figures, the recess at the bottom of the first groove 19 is shown filled with the second insulating material 7, but this is not limited to this case. For example, at least a portion of the first groove 19 may be covered with the second insulating material 7. At least a portion of the first groove 19 may be impregnated or filled with the second insulating material 7, or the entire first groove 19 may be filled with the second insulating material 7.

[0063] 6 to 9 show the case where the first groove portion 19 is formed at a position adjacent to the first insulating material 13, but this is not particularly limited to this case. The first groove portion 19 may be formed away from the first insulating material 13. An example of this case is shown in FIG.

[0064] FIG. 10 is a cross-sectional view that illustrates a schematic diagram of a capacitor element 2 included in a solid electrolytic capacitor in accordance with a ninth embodiment. In FIG. 10, the first groove 19 is formed away from the first insulating material 13. The first groove 19 is filled with the second insulating material 7, which prevents air from entering. The porous portion 6b is present in the portion of the third region 36c on the first region 36a side, and the second insulating material 7 may be included in this portion in an impregnated (or filled) state. The porous portion 6b is not present below the first groove 19, but this is not limited to this case, and the porous portion 6b may be provided. The second insulating material may be included in the porous portion 6b below the first groove 19 in an impregnated (or filled) state. Other than these, the present embodiment is the same as the case of FIG. 6, and the explanations of FIG. 1 and FIG. 6 can be referred to.

[0065] Fig. 11 is a cross-sectional view that shows a schematic of a capacitor element 2 included in the solid electrolytic capacitor according to the tenth embodiment. Fig. 12 is a cross-sectional view that shows a schematic of a capacitor element 2 included in the solid electrolytic capacitor according to the eleventh embodiment. These figures show an example in which a solid electrolyte layer 9 is disposed in at least a part of a region of the separator 16c that is closer to the cathode forming portion 16b than the first insulating material 13 (i.e., the second region 36b). By disposing the solid electrolyte layer 9 in at least a part of the second region 36b of the separator 16c, intrusion of air into the second region 36b is suppressed.

[0066] 11, in separation portion 16c, thin portion 26 is formed, and first insulating material 13 is disposed on the surface of the portion of thin portion 26 on the anode portion 16a side. Second groove portion 29 is provided in second region 36b adjacent to first insulating material 13. Then, solid electrolyte layer 9 is formed in a state in which it penetrates into second groove portion 29, so that solid electrolyte layer 9 is disposed in at least a portion of second region 36b.

[0067] 12 differs from FIG 11 in that in the second region 36b, the second groove portion 29 is formed by removing the porous portion 6b, and there is no porous portion 6b below the second groove portion 29. However, other than this, it is the same as FIG 11, and the explanation of FIG 11 can be referred to.

[0068] It is sufficient that the solid electrolyte layer 9 is disposed in at least a portion of the second region 36b. For example, the solid electrolyte layer 9 may penetrate at least a portion of the second groove portion 29. The solid electrolyte layer 9 may be disposed so as to cover at least a portion of the second groove portion 29. From the viewpoint of enhancing the effect of suppressing the intrusion of air, it is preferable that the solid electrolyte layer 9 penetrates the entire second groove portion 29 (in other words, the second groove portion 29 is filled with the solid electrolyte layer 9).

[0069] 11 and 12, although not shown, a second insulating material 7 may be further disposed in at least a portion of the second groove portion 29. In this case, leakage current of the solid electrolytic capacitor can be further suppressed.

[0070] 13 is a cross-sectional view that illustrates a schematic diagram of a capacitor element 2 included in a solid electrolytic capacitor according to the twelfth embodiment. In FIG. 13, a thin portion 26 is formed in the separation portion 16c, and a first insulating material 13 is disposed on the surface of the thin portion 26. In the illustrated example, a groove portion (third groove portion 39) is formed by removing the porous portion 6b in at least a part of the cathode formation portion 16b. The solid electrolyte layer 9 is formed in a state in which it penetrates into the third groove portion 39, so that the solid electrolyte layer 9 is disposed in at least a part of the third groove portion 39.

[0071] The solid electrolyte layer 9 may penetrate at least a part of the third groove 39, or may be disposed so as to cover at least a part of the third groove 39. From the viewpoint of increasing the effect of suppressing the penetration of air, it is preferable that at least the entire surface of the porous portion 6b around the third groove 39 (in other words, the entire inner wall of the third groove 39) is covered with the solid electrolyte layer 9. From the same viewpoint, it is more preferable that the solid electrolyte layer 9 penetrates the entire third groove 39 (in other words, the third groove 39 is filled with the solid electrolyte layer 9). Furthermore, by filling the third groove 39 with the solid electrolyte layer 9, the effective area of ​​the solid electrolyte layer 9 can be increased.

[0072] The shape of the third groove portion 39 is not particularly limited, and may be columnar (e.g., cylindrical or prismatic), or may be a shape that decreases in diameter from the surface of the porous portion 6b toward the base portion 6a (e.g., a tapered cross section). In the third groove portion 39, it is preferable that the solid electrolyte layer 9 enters even in the portion with a small diameter, and the solid electrolyte layer 9 is disposed therein.

[0073] From the viewpoint of easily ensuring a higher effect in suppressing the intrusion of air into the capacitor element 2, the third groove portion 39 is preferably formed at a position on the separation portion 16c side in the longitudinal direction of the cathode formation portion 16b. For example, when the length of the cathode formation portion 16b is L, the third groove portion 39 is preferably provided from the boundary between the separation portion 16c and the cathode formation portion 16b to a position of length 0.3L (preferably to a position of 0.25L).

[0074] The third groove portion 39 may be formed in the entire region between the boundary between the separating portion 16c and the cathode forming portion 16b and a position 0.3L (preferably 0.25L) away from the boundary, or may be formed in a part of this region. One third groove portion 39 may be formed extending over the entire region. One third groove portion 39 may be formed in the cathode forming portion 16b, or a plurality of third groove portions 39 may be formed. The width of the third groove portion 39 is, for example, 0.01 μm or more. The width of the third groove portion 39 may be 0.1 μm or more, 1 μm or more, or 5 μm or more. The width of the third groove portion 39 is preferably 0.3L or less or 0.25L or less, and may be 50 μm or less or 30 μm or less. These lower limit values ​​and upper limit values ​​can be combined arbitrarily. The width of the third groove portion 39 is the length of the third groove portion 39 in the direction along the longitudinal direction of the cathode forming portion 16b.

[0075] In the illustrated example, the porous portion 6b is not present under the third groove portion 39, but this is not limited to the case, and the porous portion 6b may be provided. From the viewpoint of enhancing the effect of suppressing the intrusion of air, it is preferable that the thickness of the porous portion 6b under the third groove portion 39 is small. For example, when the thickness of the porous portion 6b is T, the depth of the third groove portion 39 is preferably 0.95T or more, and may be 0.98T or more. The depth of the third groove portion 39 is, for example, T or less. From the viewpoint of further enhancing the effect of suppressing the intrusion of air, it is preferable that the porous portion 6b is not present under the third groove portion 39.

[0076] 13 shows an example in which the third groove 39 is formed at a position spaced apart from the separating portion 16c, but the present invention is not limited to this example. The third groove 39 may be formed at a position adjacent to the separating portion 16c of the cathode forming portion 16b.

[0077] In the tenth, eleventh and twelfth embodiments, it is not necessary to configure the separator 16c to include the second insulating material 7 as in the fifth to ninth embodiments. However, this is not limited to this case, and the separator 16c may be configured to include the second insulating material 7 as shown in the fifth to ninth embodiments. In Figs. 11 to 13, the state of the second region 36b and the third region 36c is different from that in Fig. 6, but the other parts are the same as those in Fig. 6, and the explanations of Figs. 1 and 6 can be referred to. In the twelfth embodiment, the second groove 29 may be formed as in the tenth or eleventh embodiment, and the solid electrolyte layer 9 may penetrate into the second groove 29. In addition, the second insulating material 7 may be further disposed in at least a part of the second groove 29. In the first to ninth embodiments, the second groove 29 and / or the third groove 39 may be formed as in the tenth, eleventh or twelfth embodiment, and the solid electrolyte layer 9 may penetrate into these grooves. Moreover, in at least a partial region of the second groove portion 29, a second insulating material 7 may be further disposed.

[0078] FIG. 14 is a cross-sectional view that shows a schematic diagram of the capacitor element 2 included in the solid electrolytic capacitor according to the thirteenth embodiment. In FIG. 14, the thin portion 26 is formed in the separation portion 16c, and the first insulating material 13 is disposed on the surface of the thin portion 26. In FIG. 14, the second groove portion 29 is formed at least in the second region 36b by removing the porous portion 6b. The second groove portion 29 is formed in a position adjacent to the first insulating material 13 (or the first region 36a). The second groove portion 29 is filled with the second insulating material 7, which suppresses the intrusion of air. In the illustrated example, the second groove portion 29 is formed so as to straddle the second region 36b and the cathode forming portion 16b. However, this is not limited to this case, and the second groove portion 29 may be formed only in the second region 36b. The second groove portion 29 may be formed in a part of the second region 36b, or may be formed in the entire second region 36b.

[0079] 14, the second insulating material 7 does not necessarily need to be filled so as to fill the entire second groove portion 29, but may be disposed in at least a partial region of the second groove portion 29. The second insulating material 7 may be disposed so as to cover at least a partial region of the second groove portion 29. The second groove portion 29 may also be impregnated with the second insulating material 7. For example, the second groove portion 29 may be filled with the second insulating material 7 so as to partially fill the second groove portion 29, or the second insulating material 7 may be disposed on at least a part of the inner surface of the second groove portion 29.

[0080] A porous portion 6b is present in a portion of the cathode-forming portion 16b adjacent to the second groove portion 29, and this portion may be impregnated (or filled) with the second insulating material 7. In FIG. 14, the porous portion 6b is not present below the second groove portion 29, but this is not limited to this case, and the porous portion 6b may be provided. When the porous portion 6b is provided below the second groove portion 29, the second insulating material 7 may be included in this portion of the porous portion 6b in a state of being impregnated (or filled). From the viewpoint of enhancing the effect of suppressing the intrusion of air, it is preferable that the porous portion 6b is not present below the second groove portion 29.

[0081] 14, as in the case of FIG. 3, the surface of the recess (neck) may be covered with third insulating material 17. Also, third insulating material 17 may be attached to at least the periphery of first region 36a. Third insulating material 17 may cover at least a part of at least one of cathode extraction layer 10 and solid electrolyte layer 9. For the position of third insulating material 17, see the description of FIG. 3 or FIG. 4.

[0082] In Fig. 14, the state of the second region 36b and the third region 36c is different from that in Fig. 6, but otherwise it is the same as Fig. 6, and the explanations of Figs. 1 and 6 can be referred to. In Fig. 14, the third region 36c does not need to be configured to include the second insulating material 7 as in the fifth to ninth embodiments, but this is not limited to this case, and the third region 36c may be configured to include the second insulating material 7 as shown in the fifth to ninth embodiments. In the thirteenth embodiment, the second groove portion 29 and / or the third groove portion 39 may be formed as shown in the tenth, eleventh, or twelfth embodiments, and the solid electrolyte layer 9 may penetrate into these grooves.

[0083] The structure of the solid electrolytic capacitor will be described in more detail below. (Capacitor elements 2, 102A to 102C) Each of capacitor elements 2, 102A to 102C includes an anode foil 6, a dielectric layer, and a cathode portion 8. The cathode portion 8 includes a solid electrolyte layer 9 and a cathode extraction layer 10 that covers the solid electrolyte layer 9.

[0084] The solid electrolytic capacitor needs to have at least one capacitor element 2, and may have a plurality of capacitor elements (such as capacitor elements 102A to 102C) as shown in Fig. 5. The number of capacitor elements included in the solid electrolytic capacitor may be determined depending on the application.

[0085] (Anode foil 6) The anode foil 6 may contain a valve metal, an alloy containing a valve metal, a compound containing a valve metal, etc. These materials may be used alone or in combination of two or more. For example, aluminum, tantalum, niobium, and titanium are preferably used as the valve metal. The anode foil 6 having the porous portion 6b on the surface of the base portion 6a can be obtained by roughening the surface of a metal foil containing a valve metal by, for example, etching.

[0086] (Dielectric layer) The dielectric layer is formed by anodizing the valve metal on the surface of the anode foil 6 by chemical conversion treatment or the like. The dielectric layer may be formed so as to cover at least a part of the anode foil 6. The dielectric layer is usually formed on the surface of the anode foil 6. Since the dielectric layer is formed on the surface of the porous portion of the anode foil 6, it is formed along the inner wall surfaces of the holes and depressions (pits) on the surface of the anode foil 6.

[0087] The dielectric layer contains an oxide of the valve metal. For example, when tantalum is used as the valve metal, the dielectric layer contains Ta2O5, and when aluminum is used as the valve metal, the dielectric layer contains Al2O3. The dielectric layer is not limited to this, and may be anything that functions as a dielectric. When the surface of the anode foil 6 is porous, the dielectric layer is formed along the surface of the anode foil 6 (including the inner wall surfaces of the holes).

[0088] (First insulating material 13) As the first insulating material 13, an insulating resin or the like is used. From the viewpoint of easiness of disposing on the surface of the porous portion 6b of the separating portion 16c, the first insulating material 13 is preferably an insulating tape (such as a resist tape), but is not limited thereto. The first insulating material 13 may be a coating of a coating agent containing the first insulating material 13. The first insulating material 13 may be a thermoplastic resin (or a thermoplastic resin composition), or may be a curable resin (or a curable resin composition) or a cured product thereof (including a semi-cured product). The curable resin (or a curable resin composition) may be thermosetting or photocurable.

[0089] Examples of insulating resins include curable resins (epoxy resins, polyimides, etc.), photoresists, and thermoplastic resins (e.g., polyolefins, polyesters, polyamides, thermoplastic polyimides, etc.). The curable resins may be either thermosetting or photosetting. The photosetting resins may be cured by visible light or ultraviolet light. The insulating resin may be a curable resin composition. One type of insulating resin may be used, or two or more types may be used in combination.

[0090] (Second insulating material 7) As the second insulating material 7, an insulating resin or the like is used. From the viewpoint of easily securing high permeability or penetration into the porous portion 6b, the first groove portion 19, or the second groove portion 29, the second insulating material 7 is preferably a curable resin or a cured product (including a semi-cured product) of the composition thereof. The curable resin may be thermosetting or photosetting. Examples of the photosetting resin or the composition thereof include those that are cured by ultraviolet light or visible light. From the viewpoint of easily impregnating or filling the first groove portion 19 or the second groove portion 29, it is preferable to use a photosetting (particularly ultraviolet light curable) resin or a composition thereof. Examples of the curable resin include those described below. The curable resin composition may include at least one selected from the group consisting of a curing agent, a curing accelerator, a catalyst, and an additive.

[0091] (Third insulating material 17) As the third insulating material 17, an insulating resin or the like is used. The third insulating material 17 may be a thermoplastic resin, a curable resin or a cured product of a composition thereof. The third insulating material 17 may be the same as the second insulating material 7 or may be different. As the curable resin, for example, those exemplified for the second insulating material 7 described later may be mentioned.

[0092] Examples of the thermoplastic resin include at least one selected from the group consisting of vinyl resins (e.g., vinyl chloride, vinyl acetate, aromatic vinyl resins), polyolefins (e.g., polyethylene, polypropylene), acrylic resins, polyamides, polycarbonates, thermoplastic polyimides, and polyamideimides. Examples of the aromatic vinyl resin include polystyrene and acrylonitrile-butadiene-styrene copolymers (ABS resins).

[0093] (Fourth Insulating Material 117) The fourth insulating material 117 can be selected from, for example, those exemplified as the third insulating material 17. From the viewpoint of facilitating the formation of a thin coating, the fourth insulating material 117 is preferably a curable resin or a cured product of its composition. The curable resin may be thermosetting or photosetting. The fourth insulating material 117 may be the same as the second insulating material 7 or may be different. The fourth insulating material 117 may be the same as the third insulating material 17 or may be different.

[0094] (Cathode part 8) (Solid electrolyte layer 9) The solid electrolyte layer 9 constituting the cathode section 8 includes a conductive polymer, and may further include a dopant or an additive, if necessary. Examples of the conductive polymer include polypyrrole, polythiophene, polyaniline, and derivatives thereof. The solid electrolyte layer 9 can be formed, for example, by chemical polymerization and / or electrolytic polymerization of raw material monomers. Alternatively, the solid electrolyte layer 9 can be formed by contacting a solution in which a conductive polymer is dissolved or a dispersion in which a conductive polymer is dispersed with the dielectric layer. The solid electrolyte layer 9 may be formed so as to cover at least a part of the dielectric layer. In the case of electrolytic polymerization, a conductive precoat layer may be formed prior to the electrolytic polymerization. The solid electrolyte layer 9 may be formed directly on the dielectric layer, or may be formed via a precoat layer.

[0095] (Cathode extraction layer 10) Cathode extraction layer 10 constituting cathode section 8 includes carbon layer 11 and metal paste layer 12. Carbon layer 11 may be made of any conductive carbon material such as graphite, as long as it is conductive. Metal paste layer 12 may be a silver paste layer. For the silver paste layer, a composition containing silver powder and a binder resin (such as an epoxy resin) may be used, for example. The configuration of cathode extraction layer 10 is not limited thereto, and may be any configuration having a current collecting function. Cathode extraction layer 10 is formed so as to cover at least a portion of solid electrolyte layer 9.

[0096] (Exterior body 3) The exterior body 3 covers the capacitor element 2 and a portion of the lead terminals 4, 5. From the viewpoint of preventing air from entering the exterior body 3, it is desirable that the capacitor element 2 and a portion of the lead terminals 4, 5 are sealed with the exterior body 3. Although the exterior body 3 is a resin exterior body in FIGS. 1 and 2, this is not the only case, and the exterior body 3 may be a case capable of housing the capacitor element 2. The resin exterior body is formed by sealing the capacitor element 2 and a portion of the lead terminals 4, 5 with a resin material. The case may be a combination of a container that houses the capacitor element 2 and a sealing body that covers the opening of the container. The container or sealing body is formed of, for example, a metal material or a resin material.

[0097] The resin exterior preferably contains a cured product of a curable resin composition, and may contain a thermoplastic resin or a composition containing the same. Examples of the resin material constituting the case include a thermoplastic resin or a composition containing the same. Examples of the metal material constituting the case include metals such as aluminum, copper, and iron, or alloys thereof (including stainless steel and brass).

[0098] (Lead terminals 4, 5) One end of each of the lead terminals 4 and 5 is electrically connected to the capacitor element 2, and the other end is drawn out of the exterior body 3. In the solid electrolytic capacitor 1, one end of each of the lead terminals 4 and 5 is covered by the exterior body 3 together with the capacitor element 2. As the lead terminals 4 and 5, any lead terminal used in a solid electrolytic capacitor may be used without any particular limitation, and for example, a so-called lead frame may be used. Examples of materials for the lead terminals 4 and 5 include metals such as copper or alloys thereof.

[0099] [Solid electrolytic capacitor manufacturing method] The solid electrolytic capacitor can be manufactured, for example, by a manufacturing method including a step of preparing a capacitor element (first step), a step of electrically connecting a lead terminal to the capacitor element (second step), and a step of covering the capacitor element and a portion of the lead terminal with an exterior body (third step). Each step will now be described in more detail.

[0100] (1st step) In the first step, the capacitor elements 2, 102A to 102C are fabricated. The first step may include the steps of preparing an anode foil 6, forming a dielectric layer, forming a separator 16c, disposing or impregnating a first insulating material 13, forming a solid electrolyte layer 9, and forming a cathode extraction layer 10. The first step may include the step of disposing or impregnating a second insulating material in at least a partial region of the separator 16c. The first step may include the step of covering at least a portion of the first insulating material 13, the solid electrolyte layer 9, the cathode extraction layer 10, etc. with a third insulating material 17.

[0101] (Step of Preparing Anode Foil 6) The anode foil 6 can be prepared, for example, by roughening the surface of a metal foil containing a valve metal. By roughening, a porous portion 6b is formed on the surface of the base portion 6a. The roughening may be performed by etching (e.g., electrolytic etching) the surface of the metal foil as long as it can form irregularities on the surface of the base portion.

[0102] (Process for forming dielectric layer) In this step, a dielectric layer is formed on the anode foil 6. The dielectric layer is formed by anodizing the anode foil 6. The anodization can be performed by a known method, for example, chemical conversion treatment. The chemical conversion can be performed, for example, by immersing the anode foil 6 in a chemical conversion solution and applying a voltage between the anode foil 6 as an anode and a cathode immersed in the chemical conversion solution. As the chemical conversion solution, for example, an aqueous solution of phosphoric acid is preferably used.

[0103] (Step of forming separation portion 16c) The anode foil 6 on which the dielectric layer is formed is divided into an anode portion 16a, a cathode forming portion 16b, and a separation portion 16c between the anode portion 16a and the cathode forming portion 16b. Then, at least a part of the porous portion 6b is compressed and / or removed in at least a part of the separation portion 16c. For example, in at least a part of the separation portion 16c, a groove portion (or a thin portion 26) may be formed by compressing or partially removing the porous portion 6b. Compression and removal may be combined as necessary. Compression can be performed by pressing or the like. Removal of the porous portion 6b can be performed by cutting, laser processing, or the like.

[0104] When the first groove portion 19 is formed in the third region 36c, the first groove portion 19 may be formed in this step. The first groove portion 19 can be formed by compressing or removing the porous portion 6b in the third region 36c in the same manner as the above-mentioned groove portion. The first groove portion 19 may be formed continuously with the first region 36a, or may be formed spaced apart from the first region 36a.

[0105] When the second groove portion 29 is formed in the second region 36b, the second groove portion 29 may be formed in this step. The second groove portion 29 can be formed by compressing or removing the porous portion 6b in the second region 36b in the same manner as the above-mentioned groove portion. The second groove portion 29 may be formed continuously with the first region 36a, or may be formed spaced apart from the first region 36a.

[0106] When the third groove 39 is formed in the cathode forming portion 16b, the third groove 39 may be formed in this step. The third groove 39 can be formed by compressing or removing the porous portion 6b in the cathode forming portion 16b in the same manner as the above-mentioned groove. The third groove 39 may be formed continuously with the second region 36b, or may be formed spaced apart from the second region 36b.

[0107] It should be noted that the first groove 19 and the second groove 29 do not necessarily have to be formed in this step, but may be formed after this step and before the step of forming the solid electrolyte layer 9. The third groove 39 does not necessarily have to be formed in this step, but may be formed after the step of forming the dielectric layer and before the step of forming the solid electrolyte layer 9.

[0108] (Step of disposing or impregnating first insulating material 13) The first insulating material 13 is disposed or impregnated in at least a part of the separating portion 16c. The first insulating material 13 is preferably disposed on the surface of the thin portion 26. For example, the first insulating material 13 may be disposed by attaching an insulating tape (such as a resist tape) to the surface of the separating portion 16c, or may be disposed on the surface of the porous portion 6b by coating with a coating agent containing the first insulating material 13. By disposing the first insulating material 13 prior to the step of forming the solid electrolyte layer 9, it is possible to suppress the conductive polymer from creeping up to the anode portion 16a side when the solid electrolyte layer 9 is formed. Examples of the first insulating material include insulating resins.

[0109] In the solid electrolytic capacitor according to the second aspect of the present disclosure, the first insulating material 13 may be formed by impregnating at least a portion of the separation portion 16c with a coating agent containing the first insulating material 13. Alternatively, the first insulating material 13 may be disposed by attaching an insulating tape to the surface of the separation portion 16c, and at least a portion of the separation portion 16c may be impregnated with the coating agent containing the first insulating material 13. Either the impregnation with the coating agent or the disposition of the insulating tape may be performed first.

[0110] (Step of forming solid electrolyte layer 9) In this step, a solid electrolyte layer 9 is formed on the dielectric layer. The solid electrolyte layer 9 may be formed so as to cover at least a part of the dielectric layer. The solid electrolyte layer 9 contains a conductive polymer, and may further contain a dopant, an additive, or the like, as necessary.

[0111] Examples of the conductive polymer include polypyrrole, polythiophene (poly(3,4-ethylenedioxythiophene) (PEDOT), etc.), polyaniline, and derivatives thereof. Examples of the dopant include paratoluenesulfonic acid, naphthalenesulfonic acid, and polystyrenesulfonic acid (PSS).

[0112] The solid electrolyte layer 9 can be formed, for example, by chemical polymerization and / or electrolytic polymerization of raw material monomers. Alternatively, the solid electrolyte layer 9 can be formed by contacting a solution in which a conductive polymer is dissolved, or a solution or dispersion in which a conductive polymer is dissolved or dispersed in a liquid medium (such as a solvent), with the dielectric layer. Examples of the liquid medium include water, an organic solvent, and mixtures of these. In particular, electrolytic polymerization is likely to proceed on the surface side of the solid electrolyte layer (the side opposite the dielectric layer). stomach Therefore, the solid electrolyte layer 9 is likely to be formed densely, but since the process is difficult to progress inside, voids are likely to occur. Air is likely to enter the capacitor element 2 through these voids. Therefore, the effect of filling the porous portion 6b with the second insulating material is particularly pronounced when the solid electrolyte layer 9 is formed by electrolytic polymerization. In the case of electrolytic polymerization, a precoat layer may be formed on the dielectric layer prior to the electrolytic polymerization. The precoat layer is formed, for example, of a conductive material (conductive polymer, inorganic conductive material, etc.). The conductive material constituting the precoat layer is not particularly limited, and for example, a known material can be used.

[0113] When disposing the solid electrolyte layer 9 in at least a portion of the second region 36b of the separation portion 16c (e.g., at least a portion of the region of the second groove portion 29), the solid electrolyte layer 9 can be formed in the second region 36b, for example, by carrying out chemical polymerization or electrolytic polymerization while the second region 36b is in contact with a polymerization liquid, or by bringing a solution or dispersion containing a conductive polymer into contact with the second region 36b.

[0114] When disposing the solid electrolyte layer 9 in at least a portion of the third groove portion 39, the solid electrolyte layer 9 can be formed in the third groove portion 39, for example, by carrying out chemical polymerization or electrolytic polymerization while bringing the third groove portion 39 into contact with a polymerization liquid, or by bringing a solution or dispersion liquid containing a conductive polymer into contact with the third groove portion 39.

[0115] (Step of forming cathode extraction layer 10) In this step, cathode extraction layer 10 is formed by sequentially laminating carbon layer 11 and metal paste layer 12 on solid electrolyte layer 9.

[0116] In addition, as shown in Figure 5, when stacking multiple capacitor elements, after producing each capacitor element as described above, the capacitor elements may be stacked to prepare a stack of capacitor elements in the first step.

[0117] (Step of disposing or impregnating a second insulating material) The second insulating material may be disposed or impregnated in at least a partial region of the separation portion 16c. When the second groove portion 29 is provided so as to straddle the separation portion 16c and the cathode formation portion 16b, the second insulating material 7 may be impregnated into the second groove portion 29. In this case, the second insulating material 7 is contained not only in a part of the separation portion 16c but also in a part of the cathode formation portion 16b.

[0118] The method for manufacturing the solid electrolytic capacitor according to the first aspect of the present disclosure may include a step of impregnating at least the porous portion 6b of the first region 36a with the second insulating material. The second insulating material may be impregnated (or filled) at least in the porous portion 6b of the first region 36a. The second insulating material is filled in at least the porous portion 6b of the first region 36a by impregnating the periphery of the first insulating material 13 with the second insulating material. At this time, the second insulating material may be impregnated (or filled) in at least one of the porous portions 6b of the second region 36b on the cathode forming portion 16b side and the third region 36c on the anode portion 16a side. Also, as in the case of FIG. 4, the metal paste layer 12 may be impregnated with the second insulating material.

[0119] When manufacturing the solid electrolytic capacitor according to the second aspect of the present disclosure, the second insulating material 7 may be disposed or impregnated in at least a part of the region of the separation portion 16c closer to the anode portion 16a than the first insulating material 13 (i.e., the third region 36c). For example, the first groove portion 19 may be formed in at least a part of the third region 36c, and the second insulating material 7 may be disposed in at least a part of the first groove portion 19. In this case, the second insulating material 7 may be disposed so as to cover at least a part of the first groove portion 19. Also, the second insulating material 7 may be impregnated into the porous portion 6b in at least a part of the third region 36c. These may be combined.

[0120] The second insulating material 7 may be disposed or impregnated in at least the third region 36c. The second insulating material 7 is preferably impregnated or filled in the first groove portion 19. The second insulating material 7 may be impregnated or filled in the first region 36a and / or the second region 36b on the cathode forming portion 16b side. For example, the second insulating material 7 may be impregnated around the first insulating material 13 to fill the first region 36a with the second insulating material 7. The second insulating material 7 may be impregnated or filled in the porous portion 6b on the anode portion 16a side relative to the third region 36c.

[0121] When manufacturing the solid electrolytic capacitor according to the fifth aspect of the present disclosure, the first insulating material 13 (or the first region 36a) adjacent to the cathode forming portion 16b side of the separation portion 16c is doThe second insulating material 7 is disposed in at least a partial region of the formed second groove portion 29. At least a partial region of the second groove portion 29 may be covered with the second insulating material 7. The second groove portion 29 may be impregnated or filled with the second insulating material 7. By impregnating the second groove portion 29 with the second insulating material, at least a portion of the cathode formation portion 16b adjacent to the second groove portion 29 may be impregnated or filled with the second insulating material.

[0122] The step of impregnating with second insulating material 7 may be performed after the step of forming cathode extraction layer 10. Metal paste layer 12 may be impregnated with second insulating material 7.

[0123] When the step of impregnating the second insulating material 7 is performed after the step of forming the cathode extraction layer 10, the second insulating material 7 may be disposed so as to cover at least a portion of the solid electrolyte layer 9 and the cathode extraction layer 10. The second insulating material 7 may be disposed so as to cover at least a portion of the surface of the recess (neck) between the cathode portion 8 and the separation portion 16c (or the first insulating material 13). The second insulating material 7 disposed so as to cover at least a portion of the solid electrolyte layer 9, the cathode extraction layer 10, the neck, etc. corresponds to the third insulating material 17 in FIG. 3 or FIG. 4. The third insulating material 17 disposed in this manner is the same material as the second insulating material 7.

[0124] A known application method can be used to supply the second insulating material to the first region 36a, the second region 36b, the third region 36c, the porous portion 6b, and the surface of the capacitor element 2. The second insulating material is supplied by, for example, a coating method or a dispensing method using various coaters or dispensers, immersion, transfer (roller transfer, etc.), or the like.

[0125] From the viewpoint of facilitating impregnation of the first groove portion 19, the second groove portion 29, or the porous portion 6b with the second insulating material, it is preferable to use a curable resin (or a composition thereof) as the second insulating material. The curable resin may be photocurable or thermosetting. Examples of the curable resin include, but are not limited to, epoxy resin, phenolic resin, unsaturated polyester resin, thermosetting polyurethane resin, and thermosetting polyimide. The curable resin may be used alone or in combination of two or more kinds. The curable resin may be a one-component curing type or a two-component curing type. The curable resin composition may include, for example, at least one selected from the group consisting of a curing agent, a curing accelerator, a catalyst, and an additive.

[0126] From the viewpoint of facilitating impregnation of the second insulating material into the first groove portion 19, the second groove portion 29, or the porous portion 6b, it is preferable that the curable resin (or composition) supplied to the porous portion 6b has a low viscosity. The viscosity of the curable resin (or composition) at 25°C is, for example, 300 mPa s or less, and more preferably 100 mPa s or less. The viscosity of the curable resin (or composition) can be measured using a cone-plate viscometer at a rotation speed of 60 rpm.

[0127] Since it is desirable for the thermosetting resin (or composition) to have a low viscosity, it may contain a solvent; however, from the viewpoint of easily and efficiently filling many voids contained in the first groove portion 19, the second groove portion 29, or the porous portion 6b with the second insulating material, it is preferable to use a solvent-free curable resin (or composition).

[0128] The curable resin includes, for example, a polyfunctional compound having two or more polymerizable functional groups involved in the curing reaction, and / or a monofunctional compound having one polymerizable functional group. From the viewpoint of reducing the viscosity of the curable resin (or composition), it is preferable that the curable resin (or composition) includes at least a monofunctional compound. The curable resin may include a monofunctional compound and a polyfunctional compound. In the case of an epoxy resin, for example, a monofunctional glycidyl compound (glycidyl ether of a monohydroxy compound, glycidyl amine, etc.) may be combined with a polyfunctional glycidyl compound (polyglycidyl ether of a polyhydroxy compound, polyglycidyl amine, etc.). The polyfunctional compound may have, for example, 2 to 4 polymerizable functional groups, or may have 2 or 3 polymerizable functional groups.

[0129] The ratio of the monofunctional compound in the curable resin is, for example, preferably 50% by mass or more, and may be 70% by mass or more. When the ratio of the monofunctional compound is in such a range, even if the content of the solvent is low (especially when a solventless curable resin (or composition) is used), the viscosity of the curable resin (or composition) can be reduced. The ratio of the monofunctional compound in the curable resin is, for example, 90% by mass or less, and may be 85% by mass or less. These lower and upper limits can be combined arbitrarily.

[0130] The curable resin composition preferably contains a curing agent. The curing agent is selected according to the type of the curable resin. For example, in the case of an epoxy resin, the curing agent may be at least one selected from the group consisting of an amine compound, an acid anhydride, a phenol compound, a polymerization catalyst, and a latent curing agent.

[0131] The curing agent may be combined with a curing accelerator. The curing accelerator is selected according to the type of curable resin. Examples of the curing accelerator include tertiary amines or salts thereof, imidazoles, phosphines, phosphonium salts, and sulfonium salts.

[0132] The second insulating material filled in the first groove portion 19, the second groove portion 29, or the porous portion 6b, and the thermosetting resin (or composition) supplied to the surface of the capacitor element 2 may be cured in this process and / or a subsequent process, if necessary.

[0133] (Step of covering the solid electrolyte layer 9 or the cathode extraction layer 10 with a third insulating material) The first step may include a step of covering at least a part of at least one selected from the group consisting of the first insulating material, the solid electrolyte layer 9, the cathode extraction layer 10, and the neck with a third insulating material 17. The third insulating material 17 may be the same as or different from the second insulating material. This step may be performed after the step of forming the cathode extraction layer 10.

[0134] At least a part of the surface of at least one selected from the group consisting of the first insulating material, the solid electrolyte layer 9, the cathode extraction layer 10, and the neck may be coated with a coating agent containing the third insulating material 17, thereby covering the surface with the third insulating material. The third insulating material 17 is supplied to the surface by utilizing, for example, a coating method or a dispensing method using various coaters or dispensers, immersion, transfer (roller transfer, etc.), or the like.

[0135] The curable resin (or curable resin composition) disposed on the surface by coating or the like may be cured in at least one of this step and a subsequent step, if necessary.

[0136] (Step of covering part of the laminate with the fourth insulating material 117) 5, when a plurality of capacitor elements are laminated, the first step may further include a step of covering at least a portion of the surface of the laminate with a fourth insulating material 117. In this case, the fourth insulating material 117 may be the same as or different from the second insulating material 7. Also, the fourth insulating material 117 may be the same as or different from the third insulating material 17.

[0137] For example, similar to the case of the third insulating material 17, a coating agent containing the fourth insulating material 117 is coated onto at least a portion of the surface of the laminate, thereby forming a coating of the fourth insulating material 117 on the surface of the laminate.

[0138] The curable resin (or curable resin composition) arranged so as to cover at least a part of the surface of the laminate by coating or the like may be cured in at least one of this step and a subsequent step, if necessary.

[0139] (2nd process) In the second step, the anode lead terminal 4 and the cathode lead terminal 5 are electrically connected to the capacitor elements 2, 102A to 102C. The connection of each lead terminal may be performed after the capacitor elements are fabricated in the first step. The connection of the cathode lead terminal 5 to the capacitor elements is performed after the capacitor elements are fabricated, but the connection of the anode lead terminal 4 to the anode foil 6 may be performed at an appropriate stage in the process of fabricating the capacitor elements.

[0140] When a laminate of multiple capacitor elements is used, the anode lead terminal 4 can be connected to the anode foil 6 in the same manner as above. The cathode lead terminal 5 may be connected to a capacitor element in the same manner as above, or one end of the cathode lead terminal 5 may be connected to a laminate of multiple capacitor elements in which the cathode portions 8 are electrically connected to each other.

[0141] (3rd step) In the third step, the capacitor elements 2, 102A to 102C and parts of the lead terminals 4, 5 are covered with the exterior package 3, thereby sealing the capacitor elements with the exterior package 3. Sealing can be performed according to the type of exterior package 3. For example, when using a case-shaped exterior body having a container and a sealant, the capacitor element can be housed in the container, and the opening of the container can be sealed by covering it with the sealant while the other end of the lead terminal connected to the capacitor element is pulled out from a through hole formed in the sealant.

[0142] When a resin exterior body is used, after the capacitor element 2 and the lead terminals 4, 5 are electrically connected, the capacitor element 2 and parts of the lead terminals 4, 5 can be sealed by covering them with the resin that constitutes the resin exterior body. The resin exterior body can be formed using a molding technique such as injection molding, insert molding, or compression molding.

[0143] [Example] Hereinafter, the present disclosure will be specifically described based on examples and comparative examples, but the present disclosure is not limited to the following examples.

[0144] Example 1 A solid electrolytic capacitor A1 including a laminate in which seven capacitor elements 2 shown in FIG. 2 were laminated was produced in the following manner. (1) Preparation of capacitor element 2 An aluminum foil (thickness 100 μm) was prepared as a substrate, and the surface of the aluminum foil was etched to obtain an anode foil 6 having a porous portion 6b. The anode foil 6 was immersed in a phosphoric acid solution (liquid temperature 70° C.) with a concentration of 0.3 mass % and a direct current voltage of 70 V was applied for 20 minutes to form a dielectric layer containing aluminum oxide (Al2O3) on the surface of the anode foil 6. The anode foil 6 was divided into an anode portion 16a, a cathode forming portion 16b, and a separation portion 16c therebetween, and a part of the separation portion 16c was compressed by pressing to form a thin portion 26. An insulating resist tape (first insulating material) 13 was attached to the thin portion 26.

[0145] The anode foil 6 on which the dielectric layer was formed was immersed in a liquid composition containing a conductive material to form a precoat layer. A polymerization solution containing pyrrole (monomer of conductive polymer), naphthalenesulfonic acid (dopant), and water was prepared. The anode foil 6 on which the dielectric layer and the precoat layer were formed was immersed in the obtained polymerization solution, and electrolytic polymerization was performed at an applied voltage of 3 V to form a solid electrolyte layer 9.

[0146] A dispersion liquid in which graphite particles are dispersed in water was applied to the solid electrolyte layer 9, and then dried to form a carbon layer 11 on the surface of the solid electrolyte layer 9. Next, a silver paste containing silver particles and a binder resin (epoxy resin) was applied to the surface of the carbon layer 11, and then heated to harden the binder resin, thereby forming a metal paste layer (silver paste layer) 12. In this manner, a cathode extraction layer 10 composed of the carbon layer 11 and the metal paste layer 12 was formed. In this manner, a cathode part 8 composed of the solid electrolyte layer 9 and the cathode extraction layer 10 was formed.

[0147] Then, a two-component curing epoxy resin (solvent-free, viscosity (25°C): 100 mPa s) was supplied around the resist tape by roller transfer, and impregnated into the porous portion 6b of the anode foil 6. As a result, the porous portion 6b around the resist tape (the porous portion 6b in the second region 36b and the third region 36c) and the region of the porous portion 6b in the first region 36a covered with the resist tape were impregnated with the epoxy resin. The impregnated epoxy resin was then cured. In this manner, the capacitor element 2 was formed. The epoxy resin used was a mixture of liquid A consisting of 4-tert-butylphenyl glycidyl ether:bisphenol F type epoxy resin (mass ratio) = 75:25, and liquid B containing an acid anhydride-based curing agent and an imidazole-based curing accelerator.

[0148] (2) Assembly of solid electrolytic capacitor 1 An anode lead terminal 4, a cathode lead terminal 5, and an adhesive layer 14 were further arranged on the capacitor element 2 obtained in (1). Seven such capacitor elements 2 were stacked together to form a laminate, which was then sealed with resin to form an exterior body 3, thereby completing the solid electrolytic capacitor A1.

[0149] Example 2 A solid electrolytic capacitor A2 having a laminate in which seven capacitor elements 2 as shown in FIG. 4 were laminated was produced. After forming the cathode extraction layer 10, the capacitor element 2 was immersed in the same epoxy resin as that used in Example 1 up to the periphery of the anode portion 16a side of the resist tape (first insulating material 13), and after removal, the epoxy resin was cured. Except for this, the solid electrolytic capacitor 1 was completed in the same manner as in Example 1. In Example 2, the porous portion 6b (porous portion 6b in the second region 36b and the third region 36c) around the resist tape and the region of the porous portion 6b in the first region 36a covered with the resist tape are impregnated with epoxy resin. In addition, the surfaces of the solid electrolyte layer and the first insulating material between the first insulating material and the end of the anode portion side of the cathode extraction layer 10 are covered with epoxy resin. Furthermore, the metal paste layer 12 is also impregnated with epoxy resin.

[0150] Comparative Example 1 A solid electrolytic capacitor R1 was produced in the same manner as in Example 1, except that no epoxy resin was supplied around the resist tape or onto the surface of the capacitor element.

[0151] [evaluation] For the solid electrolytic capacitors of Examples 1 and 2 and Comparative Example 1 produced above, the capacitance, ESR, and rate of change of dielectric tangent tan δ were evaluated according to the following procedure. In a 20℃ environment, using a 4-terminal LCR meter, Solid electrolytic capacitor Initial capacitance value C0 (μF) , Zhou Initial ESR value X0 (mΩ) at a frequency of 100 kHz and initial Dielectric loss tangent The tan δ0 of each capacitor was measured. Next, the rated voltage was applied to the solid electrolytic capacitor for 1000 hours at a temperature of 145°C (heat resistance test). After that, the capacitance value C1 (μF), ESR Value X1( mΩ) and Dielectric loss tangent The tan δ1 was measured. Capacitance value C1 from Initial capacitance value C0 The value subtracted from Initial capacitance value C0 Divide by and multiply by 100 to get the capacitance Amount The rate of change (%) was calculated. The rate of change in the ESR value (%) was calculated by subtracting the initial ESR value X0 from the ESR value X1, dividing the result by the initial ESR value X0, and multiplying the result by 100. The rate of change in the dielectric tangent tanδ (%) was calculated by subtracting the initial dielectric tangent tanδ0 from the dielectric tangent tanδ1, dividing the result by the initial dielectric tangent tanδ0, and multiplying the result by 100. The results are shown in Table 1.

[0152] [Table 1]

[0153] In Examples 1 and 2, the rates of change in capacitance, ESR, and tan δ were smaller than those in Comparative Example 1. In Examples 1 and 2, impregnation of the porous portion 6b of the first region 36a with the second insulating material (epoxy resin) suppressed contact of the solid electrolyte layer 9 with air, and deterioration of the conductive polymer was suppressed, which is believed to have improved the heat resistance of the solid electrolytic capacitor.

[0154] Example 3 A solid electrolytic capacitor including a laminate in which seven capacitor elements 2 shown in FIG. 6 were laminated was fabricated in the following manner. In Example 1(1), an insulating resist tape (first insulating material) 13 was attached to the cathode forming portion 16b side of the thin portion 26. A first groove portion 19 was formed by the thin portion 26 and the resist tape on the anode portion 16a side of the resist tape. Then, a two-component curing epoxy resin (solventless, viscosity (25°C): 100 mPa s) was supplied to the first groove portion 19 by roller transfer, and impregnated into the porous portion 6b of the anode foil 6. As a result, the first groove portion 19 was impregnated with the epoxy resin, and the porous portion 6b around the first groove portion 19 (the porous portion 6b in the third region 36c, a part of the porous portion 6b in the first region 36a, and the porous portion 6b on the anode portion 16a side adjacent to the third region 36c) was impregnated with the epoxy resin. The impregnated epoxy resin was then cured. Other than these, a solid electrolytic capacitor (electrolytic capacitor A3) was produced in the same manner as in Example 1.

[0155] Comparative Example 2 A solid electrolytic capacitor (solid electrolytic capacitor R2) was produced in the same manner as in Example 3, except that the epoxy resin was not supplied to the periphery of the resist tape or to the surface of the capacitor element.

[0156] Example 4 A solid electrolytic capacitor including a laminate in which seven capacitor elements 2 shown in FIG. 12 were laminated was fabricated in the following manner. In (1) of Example 3, the cathode forming portion 16b of the thin portion 26 (second region 36b) was laser etched to form the second groove portion 29. A resist tape was applied to the entire surface of the thin portion 26. In addition, no epoxy resin was supplied to the periphery of the resist tape or to the surface of the capacitor element. Apart from these, a solid electrolytic capacitor (solid electrolytic capacitor A4) was produced in the same manner as in Example 3.

[0157] Examples 3 and 4 and Comparative Example 2 were evaluated in the same manner as in Example 1. The results are shown in Table 2.

[0158] [Table 2]

[0159] In Examples 3 and 4, the rates of change in capacitance, ESR, and tan δ were smaller than in Comparative Example 2. 3 In Example 4, it is believed that the heat resistance of the solid electrolytic capacitor was improved by impregnating the third region 36c with the second insulating material (epoxy resin), which prevented the solid electrolyte layer 9 from coming into contact with air and prevented deterioration of the conductive polymer. In Example 4, the conductive polymer was disposed in the second groove portion 29, which prevented air from entering the second region 36b and prevented deterioration of the conductive polymer in the solid electrolyte layer 9 formed on the cathode-forming portion 16b side.

[0160] Although the present invention has been described with respect to the presently preferred embodiments, such disclosure should not be interpreted as limiting. Various variations and modifications will no doubt become apparent to those skilled in the art to which the present invention pertains upon reading the above disclosure. Accordingly, the appended claims should be interpreted to cover all variations and modifications without departing from the true spirit and scope of the present invention. [Industrial Applicability]

[0161] The solid electrolytic capacitor according to the present disclosure can suppress the deterioration of the conductive polymer contained in the solid electrolyte layer and suppress the decrease in capacitance even when exposed to a high-temperature atmosphere. It can also suppress the increase in ESR and tan δ. Therefore, the solid electrolytic capacitor can be used in various applications, such as applications requiring a low ESR and high capacitance, and applications exposed to heat. These applications are merely examples and are not limited to these. [Explanation of symbols]

[0162] 1: solid electrolytic capacitor, 2, 102A, 102B, 102C: capacitor element, 3: exterior body, 4: anode lead terminal, 5: cathode lead terminal, 6: anode foil, 6a: base material portion, 6b: porous portion, 7: second insulating material, 8: cathode portion, 9: solid electrolyte layer, 10: cathode lead layer, 11: carbon layer, 12: metal paste layer, 13: first insulating material (resist tape), 14: adhesive layer, 16a: anode portion, 16b: cathode forming portion, 16c: separation portion, 17: third insulating material, 117: fourth insulating material, 19: first groove portion, 26: thin portion, 29: second groove portion, 36a: first region, 36b: second region, 36c: third region, 39: third groove portion

Claims

1. a capacitor element including an anode foil having a substrate and a porous portion on a surface of the substrate, a dielectric layer formed on at least a portion of a surface of the anode foil, a solid electrolyte layer covering at least a portion of the dielectric layer, and a cathode lead layer covering at least a portion of the solid electrolyte layer, the anode foil has an anode portion on which the solid electrolyte layer is not formed, a cathode forming portion on which the solid electrolyte layer is formed, and a separation portion between the anode portion and the cathode forming portion, the separation portion includes, in a direction parallel to a longitudinal direction of the cathode formation portion, a second region on the cathode formation portion side, a third region on the anode formation portion side, and a first region sandwiched between the second region and the third region, a first insulating material is disposed on a surface of the porous portion of the first region in the separation portion; At least a portion of the first region of the porous portion that is covered with the first insulating material includes a second insulating material; The third region includes the second insulating material.

2. The solid electrolytic capacitor of claim 1 , wherein the first insulating material is an insulating tape.

3. 3 . The solid electrolytic capacitor according to claim 1 , wherein the second region between the first insulating material of the porous portion and the cathode forming portion contains the second insulating material.

4. 4. The solid electrolytic capacitor according to claim 1, wherein the porous portion in the cathode formation portion contains the second insulating material.

5. 5. The solid electrolytic capacitor according to claim 1, wherein at least a portion of the cathode extraction layer includes the second insulating material.

6. 6. The solid electrolytic capacitor according to claim 1, wherein a third insulating material covers at least a portion of the solid electrolyte layer between the first insulating material and the end of the cathode extraction layer on the anode portion side.

7. The solid electrolytic capacitor according to claim 6 , wherein the third insulating material covers at least a portion of the cathode extraction layer.

8. a laminate in which a plurality of the capacitor elements are laminated, 8. The solid electrolytic capacitor according to claim 1, wherein the fourth insulating material covers at least a portion of a surface of the laminate.

9. (i) forming a dielectric layer on at least a part of a surface of an anode foil having a substrate and a porous portion on the surface of the substrate; (ii) dividing the anode foil on which the dielectric layer is formed into an anode portion, a cathode-forming portion, and a separation portion between the anode portion and the cathode-forming portion, and compressing or partially removing the porous portion in the separation portion; (iii) the separation portion includes, in a direction parallel to a longitudinal direction of the cathode formation portion, a second region on the cathode formation portion side, a third region on the anode formation portion side, and a first region sandwiched between the second region and the third region, and a step of arranging a first insulating material on a surface of the porous portion in the first region of the separation portion; (iv) covering at least a portion of the dielectric layer in the cathode formation portion with a solid electrolyte layer; (v) covering at least a portion of the solid electrolyte layer with a cathode extraction layer; and (vi) after step (v), impregnating the porous portion with a second insulating material in at least a part of the region of the separating portion that is covered with the first insulating material, In the step (iv), the second insulating material is also impregnated into the porous portion of the third region.

10. a capacitor element including an anode foil having a substrate and a porous portion on a surface of the substrate, a dielectric layer formed on the surface of the anode foil, a solid electrolyte layer covering at least a portion of the dielectric layer, and a cathode lead layer covering at least a portion of the solid electrolyte layer, the anode foil has an anode portion on which the solid electrolyte layer is not formed, a cathode forming portion on which the solid electrolyte layer is formed, and a separation portion between the anode portion and the cathode forming portion, a first insulating material is disposed or included in a first region that is at least a part of the separation portion; The capacitor element further includes a second insulating material in at least a part of a third region of the separator that is closer to the anode portion than the first region.

11. The solid electrolytic capacitor according to claim 10 , wherein the porous portion includes at least a portion of the second insulating material.

12. A first groove portion is formed in at least a part of the third region, The solid electrolytic capacitor according to claim 10 , wherein the second insulating material is disposed in at least a partial area of ​​the first groove portion.

13. The solid electrolytic capacitor according to claim 12 , wherein the first groove portion is formed adjacent to the first insulating material.

14. The solid electrolytic capacitor according to claim 12 , wherein the first groove portion is formed apart from the first insulating material.

15. 15. The solid electrolytic capacitor according to claim 12, wherein the second insulating material is contained in a portion of the porous portion surrounding the first groove portion.

16. 16. The solid electrolytic capacitor according to claim 10, wherein a third insulating material covers at least a portion of a surface of the first insulating material and at least a portion of a surface of the solid electrolyte layer that is not covered by the cathode extraction layer.

17. a capacitor element including an anode foil having a substrate and a porous portion on a surface of the substrate, a dielectric layer formed on the surface of the anode foil, a solid electrolyte layer covering at least a portion of the dielectric layer, and a cathode lead layer covering at least a portion of the solid electrolyte layer, the anode foil has an anode portion on which the solid electrolyte layer is not formed, a cathode forming portion on which the solid electrolyte layer is formed, and a separation portion between the anode portion and the cathode forming portion, A first insulating material is disposed or included in at least a portion of the separation portion; a second groove portion is formed adjacent to the first insulating material on the cathode formation portion side of the separator, the solid electrolyte layer is disposed in at least a portion of the second groove.

18. 18. The solid electrolytic capacitor according to claim 17, further comprising a second insulating material disposed in at least a portion of the second groove portion.

19. a capacitor element including an anode foil having a substrate and a porous portion on a surface of the substrate, a dielectric layer formed on the surface of the anode foil, a solid electrolyte layer covering at least a portion of the dielectric layer, and a cathode lead layer covering at least a portion of the solid electrolyte layer, the anode foil has an anode portion on which the solid electrolyte layer is not formed, a cathode forming portion on which the solid electrolyte layer is formed, and a separation portion between the anode portion and the cathode forming portion, A first insulating material is disposed or included in at least a portion of the separation portion; a third groove portion is formed in at least a part of the cathode formation portion, the third groove portion is formed at a position separated from the separation portion and at a length of 0.3L from a boundary between the separation portion and the cathode formation portion, where L is a length of the cathode formation portion; the solid electrolyte layer is disposed in at least a portion of the third groove portion.

20. a capacitor element including an anode foil having a substrate and a porous portion on a surface of the substrate, a dielectric layer formed on the surface of the anode foil, a solid electrolyte layer covering at least a portion of the dielectric layer, and a cathode lead layer covering at least a portion of the solid electrolyte layer, the anode foil has an anode portion on which the solid electrolyte layer is not formed, a cathode forming portion on which the solid electrolyte layer is formed, and a separation portion between the anode portion and the cathode forming portion, a first insulating material is disposed or included in a first region that is at least a part of the separation portion; a second groove portion is formed adjacent to the first insulating material in a second region of the separator on the cathode formation portion side; A solid electrolytic capacitor, wherein a second insulating material is disposed in at least a portion of the second groove portion.

21. (i) forming a dielectric layer on at least a part of a surface of an anode foil having a substrate and a porous portion on the surface of the substrate; (ii) dividing the anode foil on which the dielectric layer is formed into an anode portion, a cathode-forming portion, and a separation portion between the anode portion and the cathode-forming portion, and at least one of compressing and removing at least a portion of a porous portion of the separation portion; (iii) disposing or impregnating a first insulating material in a first region that is at least a part of the separation portion; (iv) covering at least a portion of the dielectric layer in the cathode formation portion with a solid electrolyte layer; (v) covering at least a portion of the solid electrolyte layer with a cathode extraction layer; and (vi) after step (v), placing or impregnating a second insulating material in at least a part of a third region on the anode portion side of the first region in the separation portion.

22. 22. The method for producing a solid electrolytic capacitor according to claim 21, wherein in the step (vi), the porous portion is impregnated with the second insulating material in at least a part of the third region.

23. After the step (ii), but before the step (iv), a first groove portion is formed by removing the porous portion in at least a part of the third region; 23. The method for producing a solid electrolytic capacitor according to claim 21, wherein in the step (vi), the second insulating material is disposed in at least a partial region of the first groove portion.

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