Solid electrolytic capacitor

Abstract

In a solid electrolytic capacitor, a first layer and a second layer in an element laminate are laminated via an adhesive resin, the first layer is provided with a valve action metal substrate having a dielectric layer formed on the surface thereof and a solid electrolyte layer provided on the dielectric layer, and a metal foil and a first sealing part of the second layer are exposed on a first end surface. The valve action metal base body and the second sealing part are exposed on the second end face, and the first sealing part is provided with first columnar parts penetrating through the metal foils in the stacking direction and a first belt-shaped part which is arranged between the metal foils and connects the first columnar parts. The second sealing part has second columnar parts penetrating through the valve action metal base bodies in the stacking direction, and a second band-shaped part which is arranged between the valve action metal base bodies and connects the second columnar parts, and the adhesive resin is less than the first sealing part and the second sealing part. And a sealing member that is provided between the metal foil and the first columnar section, between the valve-acting metal base and the first band-shaped section, between the valve-acting metal base and the second columnar section, or between the metal foil and the second band-shaped section.

Description

Technical Field

[0001] The present utility model relates to a solid electrolytic capacitor. Background Art

[0002] In Patent Document 1, a method for manufacturing a solid electrolytic capacitor and a solid electrolytic capacitor manufactured by the manufacturing method are disclosed. The manufacturing method includes: (A) a step of preparing a first sheet; (B) a step of preparing a second sheet; (C) a step of coating the first sheet with an insulating material; (D) a step of forming a conductor layer on the first sheet; (E) a step of manufacturing a laminated sheet; (F) a step of manufacturing a laminated block; (G) a step of manufacturing a plurality of element laminates by cutting the laminated block; and (H) a step of forming a first external electrode and a second external electrode.

[0003] Prior Art Documents

[0004] Patent Document

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2019-79866 Summary of the Utility Model

[0006] Problems to be Solved by the Utility Model

[0007] In the solid electrolytic capacitor manufactured by the above manufacturing method disclosed in Patent Document 1, it has the following structure, that is, a valve action metal substrate and a metal foil on which a dielectric layer is formed on the surface are laminated via a solid electrolyte layer, thereby forming a capacitor element, and the periphery of the capacitor element is sealed with a sealing material except for the connection portion with the external electrode. However, in such a structure, sometimes a gap is generated between the valve action metal substrate, the metal foil and the sealing material, and the sealing performance of the solid electrolytic capacitor deteriorates.

[0008] The present utility model is completed to solve the above problems, and the purpose is to provide a solid electrolytic capacitor with excellent sealing performance.

[0009] Technical Solutions for Solving the Problems

[0010] The solid electrolytic capacitor of the present utility model is a solid electrolytic capacitor having an element laminate, a first external electrode, and a second external electrode. In the above-mentioned element laminate, the first layer and the second layer are laminated via an adhesive resin. The above-mentioned first layer has a valve-acting metal substrate with a dielectric layer formed on its surface and a solid electrolyte layer provided on the above-mentioned dielectric layer. The above-mentioned second layer includes a metal foil. And in the above-mentioned element laminate, the above-mentioned metal foil and the first sealing portion are exposed at the first end face among the first end face and the second end face that are opposite to each other in the length direction. The above-mentioned valve-acting metal substrate and the second sealing portion are exposed at the above-mentioned second end face. The above-mentioned first external electrode is provided on the above-mentioned first end face of the above-mentioned element laminate and is connected to the above-mentioned metal foil. The above-mentioned second external electrode is provided on the above-mentioned second end face of the above-mentioned element laminate and is connected to the above-mentioned valve-acting metal substrate. The above-mentioned first sealing portion has a first columnar portion that penetrates the above-mentioned metal foil in the lamination direction and a first strip portion that is provided between the above-mentioned metal foils and connects between the above-mentioned first columnar portions. The above-mentioned second sealing portion has a second columnar portion that penetrates the above-mentioned valve-acting metal substrate in the above-mentioned lamination direction and a second strip portion that is provided between the above-mentioned valve-acting metal substrates and connects between the above-mentioned second columnar portions. The above-mentioned adhesive resin has less filler than the above-mentioned first sealing portion and the above-mentioned second sealing portion. And inside the above-mentioned element laminate, there is at least one of a first region between the above-mentioned metal foil and the above-mentioned first columnar portion, a second region between the above-mentioned valve-acting metal substrate and the above-mentioned first strip portion, a third region between the above-mentioned valve-acting metal substrate and the above-mentioned second columnar portion, and a fourth region between the above-mentioned metal foil and the above-mentioned second strip portion.

[0011] Effect of the utility model

[0012] According to the present utility model, a solid electrolytic capacitor with excellent sealing performance can be provided. Description of the drawings

[0013] Figure 1 It is a cross-sectional view schematically showing an example of the solid electrolytic capacitor according to the first embodiment of the present utility model.

[0014] Figure 2A It is a Figure 1 Stereogram of the solid electrolytic capacitor shown as viewed from the first end face side. Figure 2B It is a Figure 1 Stereogram of the solid electrolytic capacitor shown as viewed from the second end face side.

[0015] Figure 3 It is a Figure 1 Top view of the first end face of the element laminate constituting the solid electrolytic capacitor shown, enlarged.

[0016] Figure 4is a plan view showing an enlarged view of the second end face of the element laminate constituting the Figure 1 solid electrolytic capacitor shown.

[0017] Figure 5A is a diagram schematically showing a state in which the inside of the Figure 3 element laminate shown is seen through from the first end face side. Figure 5B is Figure 5A a cross-sectional view taken along line X1-X1 of the element laminate shown. Figure 5C is Figure 5A a cross-sectional view taken along line X2-X2 of the element laminate shown.

[0018] Figure 6A is a diagram schematically showing a state in which the inside of the Figure 4 element laminate shown is seen through from the second end face side. Figure 6B is Figure 6A a cross-sectional view taken along line X3-X3 of the element laminate shown. Figure 6C is Figure 6A a cross-sectional view taken along line X4-X4 of the element laminate shown.

[0019] Figure 7 is a plan view showing Figure 3 a modified example of the first end face shown.

[0020] Figure 8 is a plan view showing Figure 4 a modified example of the second end face shown.

[0021] Figure 9A is a perspective view schematically showing an example of the first sheet. Figure 9B is Figure 9A a perspective view showing an enlarged view of a part of the first sheet shown.

[0022] Figure 10A is a perspective view schematically showing an example of the second sheet. Figure 10B is Figure 10A a perspective view showing an enlarged view of a part of the second sheet shown.

[0023] Figure 11A is a perspective view schematically showing an example of the first sheet provided with an adhesive resin. Figure 11B is Figure 11A a perspective view showing an enlarged view of a part of the first sheet shown.

[0024] Figure 12A is a perspective view schematically showing an example of the first sheet provided with an adhesive resin and a conductive layer. Figure 12B is Figure 12A a perspective view showing an enlarged view of a part of the first sheet shown.

[0025] Figure 13A It is a perspective view schematically showing an example of a state before laminating the first sheet and the second sheet. Figure 13B It is a perspective view schematically showing an example of laminated sheets.

[0026] Figure 14A It is a perspective view schematically showing an example of a laminated block. Figure 14B It is Figure 14A A perspective view obtained by decomposing and magnifying a part of the shown laminated block.

[0027] Figure 15A It is a top view schematically showing a valve-acting metal substrate before cutting. Figure 15B It is a top view schematically showing a valve-acting metal substrate after cutting.

[0028] Figure 16A It is a top view schematically showing a metal foil before cutting. Figure 16B It is a top view schematically showing a metal foil after cutting.

[0029] Figure 17 It is a cross-sectional view schematically showing an example of an element laminate.

[0030] Figure 18A It is for Figure 17 A perspective view of the shown element laminate observed from the first end face side. Figure 18B It is for Figure 17 A perspective view of the shown element laminate observed from the second end face side.

[0031] Figure 19A It is a perspective view schematically showing an example of a laminated block after cutting. Figure 19B It is Figure 19A A perspective view obtained by decomposing and magnifying a part of the shown laminated block.

[0032] Figure 20A It is a perspective view schematically showing an example of a laminated block in which a fourth sealing portion is formed. Figure 20B It is Figure 20A A perspective view obtained by decomposing and magnifying a part of the shown laminated block.

[0033] Figure 21A It is a perspective view schematically showing an example of a singulated element laminate. Figure 21B It is Figure 21A A perspective view obtained by decomposing and magnifying a part of the shown element laminate.

[0034] Figure 22A It is a perspective view schematically showing an example of the first sheet provided with an adhesive resin. Figure 22B It isFigure 22A An enlarged perspective view of a part of the first sheet shown.

[0035] Figure 23A It is a perspective view schematically showing an example of the state before laminating the first sheet and the second sheet. Figure 23B It is a perspective view schematically showing an example of laminated sheets.

[0036] Figure 24A It is a perspective view schematically showing an example of a laminated block. Figure 24B It is Figure 24A An enlarged perspective view of a part of the laminated block shown, with the part decomposed.

[0037] Explanation of reference numerals

[0038] 1 Solid electrolytic capacitor;

[0039] 10 First sheet;

[0040] 11 Valve-acting metal substrate;

[0041] 11a Cut portion of the valve-acting metal substrate;

[0042] 11b End face of the valve-acting metal substrate;

[0043] 12 Dielectric layer;

[0044] 13 Solid electrolyte layer;

[0045] 14 Mask layer;

[0046] 15 Adhesive resin;

[0047] 16 Conductor layer;

[0048] 20 Second sheet;

[0049] 21 Metal foil;

[0050] 21a Cut portion of the metal foil;

[0051] 21b End face of the metal foil;

[0052] 30 Laminated sheets;

[0053] 40, 40a, 40b Laminated blocks;

[0054] 100 Component laminate;

[0055] 110 First layer;

[0056] 120 Second layer;

[0057] 131 First sealing portion;

[0058] 131a First columnar part;

[0059] 131b First strip part;

[0060] 132 Second sealing part;

[0061] 132a Second columnar part;

[0062] 132b Second strip part;

[0063] 133 Third sealing part;

[0064] 134 Fourth sealing part;

[0065] 141 First external electrode;

[0066] 142 Second external electrode;

[0067] A1 Sum of distances of each layer where the metal foil is exposed on the first end face;

[0068] A11, A12, A13, A14 Distances of each layer where the metal foil is exposed on the first end face;

[0069] A2 Sum of distances of each layer where the valve - acting metal matrix is exposed on the second end face;

[0070] A21, A22, A23, A24 Distances of each layer where the valve - acting metal matrix is exposed on the second end face;

[0071] B1 Maximum width of the metal foil;

[0072] B2 Maximum width of the valve - acting metal matrix;

[0073] R11 First element area of the first sheet;

[0074] R12 Second element area of the first sheet;

[0075] R21 First element area of the second sheet;

[0076] R22 Second element area of the second sheet;

[0077] E11 First end of the element area of the first sheet;

[0078] E12 Second end of the element area of the first sheet;

[0079] E21 First end of the element area of the second sheet;

[0080] E22 Second end of the element area of the second sheet;

[0081] E101 First end face of the element laminate;

[0082] The second end face of the E102 component laminate;

[0083] S11 The first side part of the component area of the first sheet;

[0084] S12 The second side part of the component area of the first sheet;

[0085] S21 The first side part of the component area of the second sheet;

[0086] S22 The second side part of the component area of the second sheet;

[0087] S101 The first side face of the component laminate;

[0088] S102 The second side face of the component laminate;

[0089] M31 The first main face of the laminated sheet;

[0090] M32 The second main face of the laminated sheet;

[0091] M101 The first main face of the component laminate;

[0092] M102 The second main face of the component laminate;

[0093] H1 The first through hole;

[0094] H2 The second through hole;

[0095] H3 The third through hole;

[0096] H4 The fourth through hole;

[0097] G The gap of the laminated block. Detailed implementation mode

[0098] Hereinafter, the solid electrolytic capacitor of the present utility model will be described.

[0099] However, the present utility model is not limited to the following structures, and can be appropriately changed and applied within the scope of not changing the gist of the present utility model. In addition, combining two or more of the following described preferred structures is also the present utility model.

[0100] (The first embodiment)

[0101] [Solid electrolytic capacitor]

[0102] Figure 1 It is a cross-sectional view schematically showing an example of the solid electrolytic capacitor according to the first embodiment of the present utility model.

[0103] Figure 1The solid electrolytic capacitor 1 shown includes an element laminate 100, a first external electrode 141, and a second external electrode 142.

[0104] As Figure 1 shown, in the element laminate 100, a first layer 110 and a second layer 120 including a metal foil 21 are laminated via an adhesive resin (not shown). The first layer 110 includes a valve-acting metal substrate 11 having a porous portion (not shown) on its surface, a dielectric layer 12 formed on the surface of the porous portion, and a solid electrolyte layer 13 provided on the dielectric layer 12.

[0105] On the dielectric layer 12, a mask layer (not shown) is provided around the solid electrolyte layer 13, and an adhesive resin is provided on the mask layer (between the mask layer and the metal foil 21) in the same planar shape as the mask layer. In addition, a conductor layer (not shown) is provided between the solid electrolyte layer 13 and the metal foil 21.

[0106] And, in the element laminate 100, the metal foil 21 and the first sealing portion 131 are exposed at a first end face E101 among a first end face E101 and a second end face E102 that are opposite to each other in the length direction (L direction) orthogonal to the lamination direction (T direction), and the valve-acting metal substrate 11 and the second sealing portion 132 are exposed at the second end face E102. Although the dielectric layer 12 is also exposed at the second end face E102 of the element laminate 100, in the following description, it is simply described as "the valve-acting metal substrate 11 and the second sealing portion 132 are exposed".

[0107] The first external electrode 141 is provided on the first end face E101 of the element laminate 100 and is connected to the metal foil 21. The second external electrode 142 is provided on the second end face E102 of the element laminate 100 and is connected to the valve-acting metal substrate 11.

[0108] Figure 2A is a Figure 1 stereoscopic view of the solid electrolytic capacitor shown as observed from the first end face side. Figure 2B is a Figure 1 stereoscopic view of the solid electrolytic capacitor shown as observed from the second end face side. Figure 3 is a Figure 1 top view of the first end face of the element laminate constituting the solid electrolytic capacitor shown, enlarged. Figure 4 is a Figure 1 top view of the second end face of the element laminate constituting the solid electrolytic capacitor shown, enlarged. In addition, Figure 1 is a Figure 2A cross-sectional view taken along line A-A of the element laminate shown.

[0109] AsFigure 1 , Figure 2A and Figure 2B As shown in Figure 2B , the component laminate 100 has a first main surface M101 and a second main surface M102 that face each other in the stacking direction (T direction), a first end surface E101 and a second end surface E102 that face each other in the length direction (L direction) orthogonal to the stacking direction, and a first side surface S101 and a second side surface S102 that face each other in the width direction (W direction) orthogonal to the stacking direction and the length direction.

[0110] In addition, the component laminate 100 further includes a third sealing portion 133 that covers each of the main surfaces M101 and M102, and a fourth sealing portion 134 that covers each of the side surfaces S101 and S102. Additionally, the third sealing portion 133 may also cover at least one of the main surfaces M101 and / or M102 of the component laminate 100.

[0111] As Figure 2A and Figure 3 shown, the first sealing portion 131 has a first columnar portion 131a that penetrates the metal foil 21 in the stacking direction, and a first strip portion 131b that is provided between the metal foils 21 and connects between the first columnar portions 131a.

[0112] As Figure 2B and Figure 4 shown, the second sealing portion 132 has a second columnar portion 132a that penetrates the valve-acting metal substrate 11 in the stacking direction, and a second strip portion 132b that is provided between the valve-acting metal substrates 11 and connects between the second columnar portions 132a.

[0113] As Figure 2A shown, the metal foil 21 is rectangular with a plurality of cutout portions 21a (wherein the number is the same among the stacked plurality of metal foils 21) provided on one side on the first end surface E101 side. Similarly, as Figure 2B shown, the valve-acting metal substrate 11 (and the dielectric layer 12) is rectangular with a plurality of cutout portions 11a (wherein the number is the same among the stacked plurality of valve-acting metal substrates 11) provided on one side on the second columnar portion 132a side. The cutout portions 11a and 21a are preferably arranged at equal intervals in the width direction. Additionally, both the cutout portions 11a and 21a are semicircular, but the shapes are not particularly limited.

[0114] Figure 5A is a diagram schematically showing a state in which the inside of the component laminate shown in Figure 3 is seen through from the first end surface side. Figure 5B is Figure 5A a cross-sectional view taken along line X1-X1 of the component laminate shown in Figure 5A . Figure 5C is Figure 5AX2-X2 line cross-sectional view of the shown element laminate. Figure 6A is a diagram schematically showing Figure 4 a state in which the inside of the shown element laminate is seen through from the second end face side. Figure 6B is Figure 6A X3-X3 line cross-sectional view of the shown element laminate. Figure 6C is Figure 6A X4-X4 line cross-sectional view of the shown element laminate.

[0115] The adhesive resin 15 that bonds the first layer 110 and the second layer 120 exists in the first region (see Figure 5A and Figure 5B ) between the metal foil 21 and the first columnar portion 131a inside the element laminate 100, and exists in the second region (see Figure 5A and Figure 5C ) between the valve-acting metal substrate 11 and the first strip portion 131b. In addition, the adhesive resin 15 exists in the third region (see Figure 6A and Figure 6C ) between the valve-acting metal substrate 11 and the second columnar portion 132a inside the element laminate 100, and exists in the fourth region (see Figure 6A and Figure 6B ) between the metal foil 21 and the second strip portion 132b. And, the adhesive resin 15 has less filler compared to the first seal portion 131 and the second seal portion 132, that is, it is rich in resin. Therefore, the adhesive resin 15 has higher flexibility compared to the first seal portion 131 and the second seal portion 132. In this way, inside the element laminate 100, the highly flexible adhesive resin 15 is interposed between the metal foil 21 and the first seal portion 131, and between the valve-acting metal substrate 11 and the second seal portion 132, thereby being able to suppress the generation of gaps between them. Therefore, the sealing performance of the solid electrolytic capacitor 1 is improved.

[0116] Here, the so-called "the adhesive resin exists in the first region" means that the adhesive resin exists in at least a part of at least one first region. In addition, the same applies when the adhesive resin exists in the second region, the third region, or the fourth region.

[0117] In addition, regarding whether "the adhesive resin has less filler than the first sealing portion", for example, it can be confirmed by observing any cross-section of the solid electrolytic capacitor (however, it is a cross-section where the adhesive resin and the first sealing portion are exposed. The same applies hereinafter). In addition, the accuracy of confirmation can also be improved by obtaining the average of the results with the observation positions changed in any plurality of cross-sections of the solid electrolytic capacitor. Also, by performing elemental mapping on the cross-section with SEM-EDX and based on the mapping area of the metal components (such as Si, Al, etc.) different from the resin components (C, O, H) around the adhesive resin and the signal intensity of EDX, the target elements of the adhesive resin and the first sealing portion are clarified and their differences are investigated, and the accuracy of confirmation can also be improved. Regarding whether "the adhesive resin has less filler than the second sealing portion" can also be confirmed by the same method.

[0118] In addition, the adhesive resin 15 may also be present in at least one of the first region, the second region, the third region, and the fourth region inside the element laminate 100.

[0119] However, from the viewpoint of sealing performance, the adhesive resin 15 is preferably present in at least one of the first region and the third region inside the element laminate 100, and more preferably present in the first region and the third region.

[0120] When the adhesive resin 15 is present in the first region, the adhesive resin 15 is present between the end face of at least one metal foil 21 forming at least one cut portion 21a and the first columnar portion 131a. In addition, when the adhesive resin 15 is present in the third region, the adhesive resin 15 is present between the end face of at least one valve-acting metal substrate 11 forming at least one cut portion 11a and the second columnar portion 132a.

[0121] The metal foil 21 has an end face 21b opposite to the first columnar portion 131a (i.e., the end face forming the cut portion 21a) (refer to Figure 5A and Figure 5B ), and the valve-acting metal substrate 11 has an end face 11b opposite to the second columnar portion 132a (i.e., the end face forming the cut portion 11a) (refer to Figure 6A and Figure 6C ). The end face 21b and the end face 11b are located inside the element laminate 100 and are end faces not exposed on the first end face E101 and the second end face E102, respectively.

[0122] Moreover, from the viewpoint of sealing performance, the adhesive resin 15 preferably covers the entire end face 21b of the metal foil 21 (refer to Figure 5A and Figure 5B , especially refer to the central end face 21b in Figure 5B ), and preferably covers the entire end face 11b of the valve-acting metal substrate 11 (refer toFigure 6A and Figure 6C , particularly with reference to Figure 6C the central end face 11b) in

[0123] Here, the so-called "the adhesive resin 15 covers the entire end face 21b of the metal foil 21" means that the adhesive resin 15 covers the entire at least one end face 21b of at least one metal foil 21. The same applies when the adhesive resin 15 covers the entire end face 11b of the valve-acting metal substrate 11.

[0124] In addition, the adhesive resin 15 may cover only either the entire end face 21b of the metal foil 21 or the entire end face 11b of the valve-acting metal substrate 11.

[0125] Figure 7 is a top view showing a modified example of Figure 3 the first end face shown in Figure 8 is a top view showing a modified example of Figure 4 the second end face shown in

[0126] The adhesive resin 15 may be exposed from the inside of the element laminate 100 to the first end face E101 as shown in Figure 7 , or may be exposed from the inside of the element laminate 100 to the second end face E102 as shown in Figure 8 . When the laminated block is made into a single element laminate 100, shear stress causing interfacial peeling is generated at the first end face E101 and the second end face E102, but this shear stress can be alleviated by the exposed adhesive resin 15. Therefore, it is possible to suppress the generation of a peeling interface (gap) between the metal foil 21 and the first sealing portion 131, and to suppress the generation of a peeling interface (gap) between the valve-acting metal substrate 11 and the dielectric layer 12 and the second sealing portion 132. Therefore, the sealing performance of the solid electrolytic capacitor 1 is further improved. In addition, in the case where the first external electrode 141 and the second external electrode 142 are formed by plating, it is possible to prevent the plating solution from invading through this gap, and therefore it is possible to reduce the occurrence of LC defects caused by the precipitation of metal ions in the plating solution that has invaded the inside of the element laminate 100. And it is possible to prevent moisture in the air from invading through this gap, and therefore it is possible to reduce the corrosion of the metal foil 21 and the valve-acting metal substrate 11 by moisture and improve LC defects.

[0127] In addition, the adhesive resin 15 may be exposed from the inside of the element laminate 100 to only either the first end face E101 or the second end face E102.

[0128] In addition, when the adhesive resin 15 is exposed to the first end face E101 and / or the second end face E102, generally, the adhesive resin 15 is exposed from the inside of the element laminate 100 only to a part of at least one of the first end face E101 and the second end face E102.

[0129] From the viewpoint of sealing performance, the adhesive resin 15 preferably does not contain a filler. By not containing a filler, the adhesive force of the adhesive resin 15 is increased, and generation of a gap inside the element laminate 100 can be suppressed more effectively. This is because the filler does not have an adhesive function, and only the resin has an adhesive function.

[0130] In addition, the Poisson's ratio of the adhesive resin 15 is preferably 0.3 or more, and more preferably 0.4 or more. Thereby, the deformation of the adhesive resin 15 becomes larger, and thus the shear stress at the time of singulation caused by the above-described cutting can be further alleviated.

[0131] In addition, the Poisson's ratio of the adhesive resin 15 can be measured using a micro hardness tester. That is, a indenter (for example, a triangular pyramid indenter including diamond) is pressed against the target portion (adhesive resin 15), and the Poisson's ratio can be measured based on the elastic recovery behavior when the load is removed.

[0132] As Figure 2A shown, the metal foil 21 and the first sealing portion 131 are exposed on the first end face E101 of the element laminate 100. The sum A1 of the distances A11, A12, A13, and A14 of each layer where the metal foil 21 is exposed on the first end face E101 in the width direction is preferably smaller than the maximum width B1 of the metal foil 21.

[0133] On the other hand, as Figure 2B shown, the valve-acting metal substrate 11 and the second sealing portion 132 are exposed on the second end face E102 of the element laminate 100. The sum A2 of the distances A21, A22, A23, and A24 of each layer where the valve-acting metal substrate 11 is exposed on the second end face E102 in the width direction is preferably smaller than the maximum width B2 of the valve-acting metal substrate 11.

[0134] Considering the filling property of the sealing material, the larger the widths of the first columnar portion 131a and the second columnar portion 132a are, the better. However, correspondingly, the proportion of the metal foil 21 and the valve-acting metal substrate 11 exposed on the first end face E101 and the second end face E102, respectively, becomes smaller, and thus the ESR increases.

[0135] Therefore, the value of A1 / B1 is preferably 0.1 or more and 0.9 or less, and more preferably 0.5 or more. In addition, the value of A2 / B2 is preferably 0.1 or more and 0.9 or less, and more preferably 0.5 or more.

[0136] In addition, the value of A1 can be the same as or different from the value of A2. Similarly, the value of B1 can be the same as or different from the value of B2. Therefore, the value of A1 / B1 can be the same as or different from the value of A2 / B2.

[0137] As will be described later, the first sealing portion 131 and the second sealing portion 132 are formed by filling a sealing material into the through holes. Therefore, it is preferable that the first columnar portion 131a and the first strip portion 131b are integrally formed, and the second columnar portion 132a and the second strip portion 132b are integrally formed. In addition, "being integrally formed" means that there is no interface at the boundary between the two.

[0138] Considering the filling property of the sealing material when forming the first sealing portion 131 and the second sealing portion 132, it is preferable that two or more first columnar portions 131a and second columnar portions 132a are respectively formed in the width direction. In this case, it is preferable that the first columnar portions 131a and the second columnar portions 132a are respectively arranged linearly from the first main surface M101 of the element laminate 100 toward the second main surface M102.

[0139] The width of each columnar portion 131a, 132a is not particularly limited, but it is preferably 10% or more and 70% or less with respect to the maximum width of the metal foil 21 or the valve-acting metal substrate 11. For example, when the maximum width of the metal foil 21 or the valve-acting metal substrate 11 is 3 mm, it is preferable to arrange three columnar portions with a width of 0.5 mm. In this case, the distance between the columnar portions is preferably 0.35 mm.

[0140] When two or more first columnar portions 131a and second columnar portions 132a are respectively formed, considering the filling property of the sealing material, it is preferable that these columnar portions are formed at equal intervals. In addition, the so-called "equal intervals" means that the width of the strip portion between the columnar portions does not have to be strictly equal in length, as long as it is controlled within a range of about 3% or less.

[0141] The width of the strip portion between the columnar portions is not particularly limited, but it is preferably 10% or more and 70% or less with respect to the maximum width of the metal foil 21 or the valve-acting metal substrate 11.

[0142] The width of the strip portion not located between the columnar portions is preferably of the same degree as the width of the strip portion located between the columnar portions.

[0143] In addition, in addition to the first sealing portion 131 and the second sealing portion 132, a third sealing portion 133 can be formed simultaneously, which will be described later. Therefore, the third sealing portion 133 covering at least one of the main surfaces M101 and / or M102 of the element laminate 100 is preferably integrally formed with the first sealing portion 131 and the second sealing portion 132.

[0144] In the solid electrolytic capacitor 1, the valve action metal substrate 11 and the metal foil 21 are connected via another conductor layer provided on the solid electrolyte layer 13. In this case, they may also be connected via a conductive adhesive layer provided on the conductor layer. The conductor layer may be composed of only a carbon layer, only a silver layer, or may be composed of two layers, namely a carbon layer as a base and a silver layer thereon.

[0145] Among them, it is preferable to provide a carbon layer as the conductor layer on the solid electrolyte layer 13, and the surface of the metal foil 21 is in direct contact with the carbon layer. More preferably, the surface of the metal foil 21 coated with carbon is in direct contact with the carbon layer.

[0146] In addition, with respect to the portion where the solid electrolyte layer 13, the conductor layer, or the conductive adhesive layer is not provided, it is preferable that the valve action metal substrate 11 and the metal foil 21 are connected via the adhesive resin 15.

[0147] [Method for manufacturing a solid electrolytic capacitor]

[0148] Hereinafter, an example of the method for manufacturing a solid electrolytic capacitor according to the present embodiment will be described for each process.

[0149] (A) Process of preparing the first sheet

[0150] First, the first sheet is prepared.

[0151] Figure 9A is a perspective view schematically showing an example of the first sheet. Figure 9B is to Figure 9A a perspective view of an enlarged part of the first sheet shown.

[0152] Figure 9A and Figure 9B The first sheet 10 shown has a plurality of element regions R11 (hereinafter referred to as the first element regions) and a plurality of element regions R12 (hereinafter referred to as the second element regions).

[0153] As Figure 9B shown, the first element region R11 is divided by a first end portion E11 and a second end portion E12 that are opposite in the length direction (L direction), and a first side portion S11 and a second side portion S12 that are opposite in the width direction (W direction) orthogonal to the above length direction. The dimension of the first element region R11 in the length direction (L direction) is larger than the dimension in the width direction (W direction). Moreover, one first through hole H1 is formed so as to straddle the first end portion E11 of the first element region R11 in the length direction, and a plurality of (in Figure 9BThere are three second through-holes H2, which extend across the second end E12 of the first element region R11 in the longitudinal direction. The first through-hole H1 includes a single elongated hole having a width greater than the width of the first element region R11, and the second through-holes H2 include a plurality of substantially circular holes having a width smaller than the width of the first element region R11.

[0154] On the other hand, although the second element region R12 has the same shape as the first element region R11, the orientations of the first end E11 and the second end E12 are opposite to those of the first element region R11.

[0155] As Figure 9A shown, in the first sheet 10, the first element regions R11 and the second element regions R12 are alternately arranged in the longitudinal direction. As Figure 9B shown, the first element region R11 shares the first end E11 and the first through-hole H1 with the adjacent second element region R12, and shares the second end E12 and the second through-holes H2 with the other adjacent second element regions R12.

[0156] And, as Figure 9A shown, in the first sheet 10, the first element regions R11 and the second element regions R12 are alternately arranged in the width direction. As Figure 9B shown, the first element region R11 shares the first side S11 with the adjacent second element region R12, and shares the second side S12 with the other adjacent second element regions R12.

[0157] As Figure 9B shown, the first sheet 10 includes a valve-acting metal substrate 11 having a porous portion (not shown) on the surface, a dielectric layer 12 formed on the surface of the porous portion, and a solid electrolyte layer 13 provided inside each of the element regions on the dielectric layer 12. In the first sheet 10, the ends and sides of each element region are covered with a mask layer 14 containing an insulating material, and the solid electrolyte layer 13 is provided in the region surrounded by the mask layer 14.

[0158] In Figure 9BIn the first sheet 10 shown, the valve-acting metal substrate 11 has porous portions on both sides, dielectric layers 12 are formed on the surfaces of the respective porous portions, and a solid electrolyte layer 13 is provided on the dielectric layer 12. However, when the second sheet is not laminated on one surface of the first sheet, it is not necessary to provide a solid electrolyte layer on the surface of the valve-acting metal substrate on the side where the second sheet (metal foil) is not laminated. In this case, it is also possible not to form a dielectric layer or a porous portion on the surface of the valve-acting metal substrate on the side where the second sheet (metal foil) is not laminated. In addition, as the first sheet 10, a sheet in which the valve-acting metal substrate 11 has a porous portion only on one side and a dielectric layer 12 is formed on the surface of the porous portion may also be used.

[0159] The first sheet is preferably produced as follows.

[0160] First, a valve-acting metal substrate 11 having a porous portion on the surface is prepared, and a dielectric layer 12 is formed on the surface of the porous portion. For example, when an aluminum foil is used as the valve-acting metal substrate, a dielectric layer containing an oxide film can be formed by anodizing the surface of the aluminum foil (also called chemical conversion treatment) in an aqueous solution containing ammonium adipate or the like.

[0161] The valve-acting metal substrate contains a valve-acting metal showing a so-called valve action. As the valve-acting metal, for example, metal monomers such as aluminum, tantalum, niobium, titanium, zirconium, or alloys containing these metals can be cited. Among them, aluminum or an aluminum alloy is preferred.

[0162] The shape of the valve-acting metal substrate is preferably a flat plate shape, more preferably a foil shape. In addition, as the porous portion, an etched layer formed on the surface of the valve-acting metal substrate or a porous layer formed by printing and sintering on the surface of the valve-acting metal substrate can be cited. An etched layer is preferred when the valve-acting metal is aluminum or an aluminum alloy, and a porous layer is preferred when the valve-acting metal is titanium or a titanium alloy.

[0163] The thickness of the valve-acting metal substrate is not particularly limited, but the thickness of the portion other than the porous portion is preferably 5 μm or more and 100 μm or less. In addition, the thickness (thickness on one side) of the porous portion is preferably 5 μm or more and 200 μm or less.

[0164] The dielectric layer formed on the surface of the porous portion becomes porous reflecting the surface state of the porous portion and has a fine concavo-convex surface shape. The dielectric layer preferably contains an oxide film of the above valve-acting metal.

[0165] In addition, from the viewpoint of improving manufacturing efficiency, as the valve-acting metal substrate having a dielectric layer formed on the surface, a chemical conversion foil that has been previously subjected to chemical conversion treatment may also be used.

[0166] Next, a mask layer 14 that covers the ends and sides of each element region is preferably formed.

[0167] The mask layer is formed, for example, by applying a mask material containing an insulating material such as an insulating resin to the surface of the valve-acting metal substrate and curing or hardening it by heating or the like. The application of the mask material is preferably performed by screen printing, dispenser coating, inkjet printing, or the like.

[0168] Examples of the insulating material for the mask layer include insulating resins such as polyphenylsulfone resin, polyethersulfone resin, cyanate resin, fluororesin (tetrafluoroethylene, tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer, etc.), a composition containing soluble polyimide siloxane and epoxy resin, polyimide resin, polyamideimide resin, and their derivatives or precursors.

[0169] Next, a first through-hole H1 is formed to straddle the first end E11 of each element region, and a second through-hole H2 is formed to straddle the second end E12 of each element region.

[0170] The first through-hole and the second through-hole are formed, for example, by laser processing, etching processing, punching processing, or the like.

[0171] Then, a solid electrolyte layer 13 is formed in the inner part of each element region on the dielectric layer 12. At this time, it is preferable to form the solid electrolyte layer 13 in the region surrounded by the mask layer 14. For example, by applying the following treatment liquid or dispersion liquid to the dielectric layer by sponge transfer, screen printing, dispenser coating, inkjet printing, etc., the solid electrolyte layer can be formed in a given region.

[0172] The solid electrolyte layer is formed, for example, by a method of forming a polymer film such as poly(3,4-ethylenedioxythiophene) on the surface of the dielectric layer using a treatment liquid containing a monomer such as 3,4-ethylenedioxythiophene, or a method of applying a dispersion liquid of a polymer such as poly(3,4-ethylenedioxythiophene) to the surface of the dielectric layer and drying it. In addition, it is preferable to form the solid electrolyte layer by forming an inner layer that fills the pores (recesses) of the dielectric layer and then forming an outer layer that covers the dielectric layer.

[0173] Examples of the material constituting the solid electrolyte layer include conductive polymers such as polypyrrole, polythiophene, and polyaniline. Among them, polythiophene is preferable, and poly(3,4-ethylenedioxythiophene) called PEDOT is particularly preferable. In addition, the above conductive polymer may contain a dopant such as polystyrene sulfonic acid (PSS).

[0174] In addition, the first through-hole H1 and the second through-hole H2 may be formed before forming the mask layer 14, or may be formed after forming the solid electrolyte layer 13.

[0175] The size of the entire first sheet is determined by the size, shape, number, arrangement, production capacity, etc. of the element regions, and is not particularly limited. The shape of the element region of the first sheet is not particularly limited, but is preferably rectangular. In this case, the first end portion and the second end portion may be shorter than the first side portion and the second side portion, or may be longer than the first side portion and the second side portion.

[0176] The shape of the first through-hole is not particularly limited as long as it has a width equal to or greater than the width of the element region.

[0177] The shape, number, arrangement, etc. of the second through-holes are not particularly limited as long as they have a width smaller than the width of the element region, but it is preferable that two or more second through-holes are formed in each element region in the width direction. In the case where two or more second through-holes are formed, these through-holes are preferably formed at equal intervals.

[0178] In addition, if the width of each of the second through-holes is too small, it is difficult to fill the sealing material in the subsequent process. On the other hand, if the ratio of the total width of the second through-holes to the width of the element region is too large, the ratio of the valve-acting metal substrate exposed on the end face of the solid electrolytic capacitor becomes small, and thus the ESR tends to increase.

[0179] (B) Step of preparing the second sheet

[0180] In addition, a second sheet is prepared.

[0181] Figure 10A is a perspective view schematically showing an example of the second sheet. Figure 10B is Figure 10A a magnified perspective view of a part of the second sheet shown.

[0182] Figure 10A and Figure 10B the second sheet 20 shown has a plurality of element regions R21 (hereinafter referred to as the first element regions) and a plurality of element regions R22 (hereinafter referred to as the second element regions).

[0183] As Figure 10B shown, the first element region R21 is defined by a first end portion E21 and a second end portion E22 that face each other in the length direction (L direction), and a first side portion S21 and a second side portion S22 that face each other in the width direction (W direction) orthogonal to the above length direction. Moreover, a plurality of (in Figure 10BThere are three third through-holes H3 such that they span the first end E21 of the first element region R21 in the longitudinal direction, and there is one fourth through-hole H4 formed such that it spans the second end E22 of the first element region R21 in the longitudinal direction. The third through-hole H3 includes a plurality of substantially round holes having a width smaller than the width of the first element region R21, and the fourth through-hole H4 includes one long hole having a width equal to or greater than the width of the first element region R21.

[0184] On the other hand, the second element region R22 has the same shape as the first element region R21, but the orientations of the first end E21 and the second end E22 are opposite to those of the first element region R21.

[0185] As Figure 10A shown, in the second sheet 20, the first element regions R21 and the second element regions R22 are alternately arranged in the longitudinal direction. As Figure 10B shown, the first element region R21 shares the first end E21 and the third through-hole H3 with the adjacent second element region R22, and shares the second end E22 and the fourth through-hole H4 with the other adjacent second element region R22.

[0186] Moreover, as Figure 10A shown, in the second sheet 20, the first element regions R21 and the second element regions R22 are alternately arranged in the width direction. As Figure 10B shown, the first element region R21 shares the first side S21 with the adjacent second element region R22, and shares the second side S22 with the other adjacent second element region R22.

[0187] As Figure 10B shown, the second sheet 20 includes a metal foil 21.

[0188] The second sheet is preferably manufactured as follows.

[0189] First, the metal foil 21 is prepared.

[0190] The metal foil preferably includes at least one metal selected from the group consisting of aluminum, copper, silver, and alloys mainly composed of these metals.

[0191] If the metal foil includes the above-mentioned metals, the resistance value of the metal foil can be reduced, and the ESR can be reduced.

[0192] In addition, as the metal foil, a metal foil having carbon coating or titanium coating on the surface by a film forming method such as sputtering or evaporation can also be used.

[0193] The thickness of the metal foil is not particularly limited, but from the viewpoint of reducing the ESR, it is preferably 5 μm or more and 100 μm or less.

[0194] Preferably, a roughened surface is formed on the surface of the metal foil.

[0195] If a roughened surface is formed on the surface of the metal foil, the adhesion between the metal foil and the solid electrolyte layer or between the metal foil and other conductor layers can be improved. In addition, since the contact area increases, the ESR can be reduced.

[0196] The method for forming the roughened surface is not particularly limited, and the roughened surface can also be formed by etching or the like. Especially when using aluminum, in terms of reducing resistance, it is preferable to perform carbon coating and titanium coating after the roughening treatment (etching treatment).

[0197] In addition, a coating layer containing an anchor coating agent can be formed on the surface of the metal foil.

[0198] If a coating layer containing an anchor coating agent is formed on the surface of the metal foil, the adhesion between the metal foil and the solid electrolyte layer or between the metal foil and other conductor layers can be improved, and thus the ESR can be reduced.

[0199] Next, a third through-hole H3 is formed so as to straddle the first end portion E21 of each element region, and a fourth through-hole H4 is formed so as to straddle the second end portion E22 of each element region.

[0200] The third through-hole and the fourth through-hole are formed, for example, by laser processing, etching processing, punching processing, or the like.

[0201] The size of the entire second sheet is not particularly limited, but it is preferably the same as the size of the entire first sheet. The shape, number, and arrangement of the element regions of the second sheet are preferably the same as those of the element regions of the opposed first sheet.

[0202] As long as the third through-hole has a width smaller than the width of the element region, its shape, number, arrangement, etc. are not particularly limited, but preferably, two or more are formed in the width direction in each element region. When two or more third through-holes are formed, these through-holes are preferably formed at equal intervals.

[0203] On the other hand, if the width of each of the third through-holes is too small, it is difficult to fill the sealing material in the subsequent process. On the other hand, if the ratio of the total width of the third through-holes to the width of the element region is too large, the proportion of the metal foil exposed on the end face of the solid electrolytic capacitor becomes small, and thus the ESR tends to increase.

[0204] As long as the fourth through-hole has a width equal to or greater than the width of the element region, its shape is not particularly limited.

[0205] (E) Step of manufacturing the laminated sheet

[0206] A laminated sheet is produced by laminating a first sheet and a second sheet such that the first ends of the respective element regions face each other and the second ends face each other. In the obtained laminated sheet, the first through-hole and the third through-hole, and the second through-hole and the fourth through-hole communicate with each other in the lamination direction, respectively.

[0207] Preferably, the second through-hole and the third through-hole linearly communicate from the first main surface to the second main surface of the laminated sheet, respectively.

[0208] When laminating the first sheet and the second sheet, the valve-acting metal substrate and the metal foil are connected via another conductor layer provided on the solid electrolyte layer. In this case, the valve-acting metal substrate and the metal foil may also be connected via a conductive adhesive layer provided on the conductor layer.

[0209] In addition, regarding the portion where the solid electrolyte layer, the conductor layer, or the conductive adhesive layer is not provided, the valve-acting metal substrate and the metal foil are connected via an adhesive resin.

[0210] Figure 11A It is a perspective view schematically showing an example of the first sheet provided with the adhesive resin. Figure 11B It is Figure 11A A perspective view of an enlarged part of the first sheet shown.

[0211] In Figure 11A and Figure 11B In, in Figure 9A and Figure 9B On the mask layer 14 of the first sheet 10 shown, an adhesive resin (adhesive layer) 15 before curing or hardening is provided.

[0212] The adhesive resin is an insulating adhesive containing at least a resin, and preferably does not contain a filler.

[0213] Examples of the resin contained in the adhesive resin include epoxy resin, phenolic resin, etc. In addition, examples of the filler that may be contained in the adhesive resin include metal oxide particles such as silica particles and alumina particles.

[0214] When the adhesive resin contains a filler, the amount of the filler is less than that of the sealing material described later. The content of the filler in the adhesive resin is not particularly limited, but is usually 0 wt% or more and 5 wt% or less, preferably 0 wt% or more and 15 wt% or less.

[0215] The adhesive resin is formed, for example, by applying an insulating adhesive before curing or hardening on the mask layer and curing or hardening it by heating or the like. The application of the insulating adhesive is preferably performed by screen printing, dispenser coating, inkjet printing, or the like.

[0216] In this way, the manufacturing method includes a step (C) of coating the first sheet with an insulating material. In step (C), the first end, the second end, the first side, and the second side of each element region of the first sheet are coated with the insulating material.

[0217] (C) The step of coating with an insulating material preferably includes a step of forming a mask layer and a step of forming an adhesive resin on the mask layer.

[0218] The composition and viscosity of the adhesive resin may be the same as those of the mask layer, but it is preferred that the composition and viscosity are different from those of the mask layer.

[0219] The height in the thickness direction of the combined mask layer and adhesive resin may be the same as the height in the thickness direction of the solid electrolyte layer, but it is preferably greater than the height in the thickness direction of the solid electrolyte layer.

[0220] Figure 12A FIG. is a perspective view schematically showing an example of the first sheet provided with the adhesive resin and the conductor layer. Figure 12B is Figure 12A a perspective view of an enlarged part of the first sheet shown.

[0221] In Figure 12A and Figure 12B In, in Figure 9A and Figure 9B On the mask layer 14 of the first sheet 10 shown, an adhesive resin 15 before curing or hardening is provided, and a conductor layer 16 is provided on the solid electrolyte layer 13.

[0222] In this way, the manufacturing method includes a step (D) of forming a conductor layer on the first sheet. In step (D), a conductor layer is formed on the solid electrolyte layer of the first sheet.

[0223] The conductor layer is preferably composed only of a carbon layer, but may also be composed only of a silver layer, or may be composed of two layers of a carbon layer as a base and a silver layer thereon. The carbon layer and the silver layer can be provided, for example, by respectively coating a carbon paste and a silver paste.

[0224] When laminating the first sheet and the second sheet, it is preferred to place the metal foil in a state where the layer located below the metal foil has adhesiveness. The carbon paste, silver paste, or solid electrolyte layer before drying is in a state with adhesiveness, so it is suitable for directly placing the metal foil. On the other hand, when the carbon layer, silver layer, or solid electrolyte layer, which is the layer located below the metal foil, is dried, it becomes difficult to bond the metal foil, so it is preferred to place the metal foil on the basis of providing a conductive adhesive layer.

[0225] Alternatively, the conductive layer may be provided not on the first sheet but on the second sheet. In this case, it is preferable to form a dam resin on the second sheet in the same pattern as the adhesive resin 15, and form the conductive layer in the area surrounded by the dam resin.

[0226] The dam resin is formed by curing or hardening an insulating adhesive containing at least resin, and preferably does not contain a filler. The dam resin can be formed using the insulating adhesive for forming the adhesive resin 15.

[0227] Figure 13A It is a perspective view schematically showing an example of the state before laminating the first sheet and the second sheet. Figure 13B It is a perspective view schematically showing an example of the laminated sheets.

[0228] As Figure 13A shown, by alternately laminating the first sheet 10 and the second sheet 20 and curing or hardening the adhesive resin 15, the Figure 13B laminated sheet 30 shown can be obtained. The laminated sheet 30 has a first main surface M31 and a second main surface M32 that face each other in the lamination direction (T direction). In addition, although the adhesive resin 15 etc. are omitted in Figure 13B (the same applies hereinafter), by alternately laminating the first sheet 10 and the second sheet 20, the adhesive resin 15 is exposed from between the first sheet 10 and the second sheet 20 to the first through-hole, the second through-hole, the third through-hole, and / or the fourth through-hole. By appropriately setting the coating amount and coating position of the adhesive resin 15, the amount and position of the exposed adhesive resin 15 can be appropriately changed.

[0229] In Figure 13A and Figure 13B , examples are shown in which five sheets of the first sheet 10 and five sheets of the second sheet 20 are laminated respectively, and the second sheet 20 is disposed on the first main surface M31 of the laminated sheet 30 and the first sheet 10 is disposed on the second main surface M32, but the number of sheets of the first sheet and the second sheet laminated is not particularly limited. In addition, the number of sheets of the first sheet and the number of sheets of the second sheet may be the same or different. Therefore, either the first sheet or the second sheet can be disposed on the main surface of the laminated sheet. In addition, when manufacturing the laminated sheet, the first sheet and the second sheet may be laminated on a substrate including glass epoxy resin etc.

[0230] (F) Process of manufacturing a laminated block

[0231] A laminated block is manufactured by filling a sealing material into the first through-hole and the third through-hole, and the second through-hole and the fourth through-hole respectively from at least one main surface side of the obtained laminated sheet.

[0232] As described above, in the laminated sheet, the first through-hole and the third through-hole, and the second through-hole and the fourth through-hole communicate with each other in the lamination direction, respectively. Therefore, it is possible to fill the sealing material into each through-hole from the main surface side of the laminated sheet. As a result, in the obtained laminated block, a first sealing portion that fills the first through-hole and the third through-hole, and a second sealing portion that fills the second through-hole and the fourth through-hole are formed.

[0233] The filling of the sealing material can be performed by a method such as a molding resin molding method, for example. At this time, in addition to the first sealing portion and the second sealing portion, a third sealing portion that covers at least one main surface of the laminated sheet can be formed simultaneously. In this way, in the step (F) of manufacturing the laminated block, it is preferable to use the sealing material to simultaneously perform the step of covering at least one main surface of the laminated sheet.

[0234] Figure 14A is a perspective view schematically showing an example of the laminated block. Figure 14B is to Figure 14A a perspective view of a part of the laminated block shown in FIG. 1, which is decomposed and enlarged.

[0235] In Figure 14A the laminated block 40 shown in FIG. 1, by filling the sealing material into the first through-hole and the third through-hole, and the second through-hole and the fourth through-hole, respectively, as Figure 14B shown in FIG. 1, a first sealing portion 131 that fills the first through-hole H1 and the third through-hole H3, and a second sealing portion 132 that fills the second through-hole H2 and the fourth through-hole H4 are formed. In addition, as Figure 14A shown in FIG. 1, the laminated block 40 further includes a third sealing portion 133 that covers each main surface.

[0236] The sealing material contains at least resin, and preferably contains resin and a filler.

[0237] Examples of the resin contained in the sealing material include epoxy resin, phenolic resin, and the like. In addition, examples of the filler contained in the sealing material include metal oxide particles such as silica particles and alumina particles.

[0238] When the sealing material contains a filler, the filler is more than the adhesive resin. The content of the filler in the sealing material is not particularly limited, but is usually 50% by weight or more and 95% by weight or less, and preferably 80% by weight or more and 90% by weight or less.

[0239] When the sealing material contains resin and a filler, from the viewpoint of ensuring the filling property of the sealing material, it is preferable that the maximum diameter of the filler is smaller than the minimum diameter of the second through-hole and the third through-hole.

[0240] In addition, the diameter of the through-hole, in the case where the cross-sectional shape is circular, refers to the diameter, and in the case of a shape other than circular, refers to the maximum length passing through the center of the cross-section.

[0241] In addition, in the case where the sealing material contains a resin and a filler, from the viewpoint of ensuring the filling property of the sealing material, it is preferable that the maximum diameter of the filler is smaller than the minimum thickness of the metal foil.

[0242] The maximum diameter of the filler diameter included in the sealing material is preferably in the range of 20 μm or more and 50 μm or less, for example.

[0243] (G) A step of manufacturing a plurality of element laminates by cutting a laminated block

[0244] A plurality of element laminates are manufactured by cutting the laminated block at the positions of the first end portion and the second end portion of each element region, and cutting the laminated block at the positions of the first side portion and the second side portion of each element region.

[0245] Figure 15A is a top view schematically showing the valve-acting metal substrate before cutting. Figure 15B is a top view schematically showing the valve-acting metal substrate after cutting.

[0246] As Figure 15A shown, in the valve-acting metal substrate 11 constituting the first sheet included in the laminated block, a first sealing portion 131 that fills the first through-hole H1 spanning the first end portion E11 of each element region and a second sealing portion 132 that fills the second through-hole H2 spanning the second end portion E12 of each element region are formed.

[0247] Therefore, if the valve-acting metal substrate 11 is cut at the positions of the first end portion E11 and the second end portion E12 of each element region by cutting or the like so that the first sealing portion 131 and the second sealing portion 132 are separated to both sides, then as Figure 15B shown, on the first end face E101 which is the cut surface on the first end portion E11 side, the first sealing portion 131 is exposed and the valve-acting metal substrate 11 is not exposed. On the other hand, on the second end face E102 which is the cut surface on the second end portion E12 side, the valve-acting metal substrate 11 and the second sealing portion 132 are exposed.

[0248] In addition, if the valve-acting metal substrate 11 is cut at the positions of the first side portion S11 and the second side portion S12 of each element region by cutting or the like, then as Figure 15B shown, the valve-acting metal substrate 11 is exposed on any cut surface.

[0249] Figure 16A is a top view schematically showing the metal foil before cutting. Figure 16BIt is a top view schematically showing the cut metal foil.

[0250] As Figure 16A shown, in the metal foil 21 constituting the second sheet included in the stacked block, a first sealing portion 131 filling the third through hole H3 crossing the first end portion E21 of each element region and a second sealing portion 132 filling the fourth through hole H4 crossing the second end portion E22 of each element region are formed.

[0251] Therefore, if the metal foil 21 is cut at the positions of the first end portion E21 and the second end portion E22 of each element region by cutting or the like so that the first sealing portion 131 and the second sealing portion 132 are separated to both sides, then as Figure 16B shown, the metal foil 21 and the first sealing portion 131 are exposed on the first end face E101 which is the cut surface on the first end portion E21 side. On the other hand, on the second end face E102 which is the cut surface on the second end portion E22 side, the second sealing portion 132 is exposed and the metal foil 21 is not exposed.

[0252] In addition, if the metal foil 21 is cut at the positions of the first side portion S21 and the second side portion S22 of each element region, then as Figure 16B shown, the metal foil 21 is exposed on any cut surface.

[0253] As described above, by cutting the stacked block at the positions of the first end portion and the second end portion of each element region, the metal foil and the first sealing portion can be exposed on the first end face of the obtained element stacked body, and the valve-acting metal substrate and the second sealing portion can be exposed on the second end face.

[0254] In addition, on the cut surface obtained by cutting the stacked block at the positions of the first side portion and the second side portion of each element region, both the metal foil and the valve-acting metal substrate are exposed, and therefore it is preferable to form a fourth sealing portion covering each side face of the element stacked body.

[0255] Figure 17 It is a cross-sectional view schematically showing an example of the element stacked body. Figure 18A It is for Figure 17 the three-dimensional view of the element stacked body shown viewed from the first end face side. Figure 18B It is for Figure 17 the three-dimensional view of the element stacked body shown viewed from the second end face side. In addition, Figure 17 it is Figure 18A the A-A line cross-sectional view of the element stacked body shown.

[0256] In Figure 17 , Figure 18A and Figure 18B the element stacked body 100 shown, as Figure 17As shown, a first layer 110 and a second layer 120 including a metal foil 21 are laminated. The first layer 110 includes a valve-acting metal substrate 11 having a porous portion (not shown) on its surface, a dielectric layer 12 formed on the surface of the porous portion, and a solid electrolyte layer 13 provided on the dielectric layer 12. The first layer 110 and the second layer 120 are alternately laminated along the lamination direction (T direction). However, considering weather resistance such as moisture resistance and heat resistance, it is preferable that Figure 17 as shown, the second layer 120 as the metal foil is located at the outermost layers on opposite sides in the lamination direction (except for the third sealing portion 133).

[0257] In addition, Figure 17 , Figure 18A and Figure 18B the mask layer 14, the adhesive resin 15, and the conductor layer 16 are omitted.

[0258] As Figure 17 and Figure 18A shown, on the first end face E101 of the element laminate 100, the metal foil 21 and the first sealing portion 131 are exposed. On the other hand, as Figure 17 and Figure 18B shown, on the second end face E102 of the element laminate 100, the valve-acting metal substrate 11 and the second sealing portion 132 are exposed.

[0259] In addition, the element laminate 100 further includes a third sealing portion 133 covering each main surface and a fourth sealing portion 134 covering each side surface.

[0260] The element laminate is preferably manufactured as follows.

[0261] First, the laminated block is cut along the first side portion and the second side portion of each element region. In cutting the laminated block, for example, a method such as cutting using a dicing saw can be applied.

[0262] Figure 19A is a perspective view schematically showing an example of the cut laminated block. Figure 19B is Figure 19A a perspective view of a part of the laminated block shown in

[0263] after being disassembled and enlarged. Figure 14A For example, by cutting the laminated block 40 shown in Figure 19A and Figure 19B along the first side portion and the second side portion of each element region, a laminated block 40a having gaps G formed along the first side portion and the second side portion is manufactured as shown in Figure 19BAs shown, on the cut side surface that appears due to cutting, the metal foil 21 and the valve-acting metal substrate 11 are exposed. Additionally, although not shown, the thickness (thickness in the T direction) of the exposed portions of the metal foil 21 and the valve-acting metal substrate 11 is larger than the thickness of the unexposed internal metal foil 21 and valve-acting metal substrate 11, and it expands in a conical shape in the up and down directions of the thickness direction.

[0264] Next, a sealing material is filled in the gaps formed in the laminated block. Thereby, a fourth sealing portion that fills the above gaps is formed. As the sealing material, for example, the sealing materials used for forming the first sealing portion and the second sealing portion can be used.

[0265] Figure 20A FIG. is a perspective view schematically showing an example of the laminated block in which the fourth sealing portion is formed. Figure 20B is Figure 20A a perspective view of a part of the laminated block shown in FIG. after being disassembled and enlarged.

[0266] By filling the gap G of the laminated block 40a shown in Figure 19A with a sealing material, a laminated block 40b in which the fourth sealing portion 134 that fills the gap G is formed as shown in Figure 20A and Figure 20B is manufactured.

[0267] Then, the laminated block is cut at the positions of the first end portion and the second end portion of each element region so that the first sealing portion 131 and the second sealing portion 132 are separated to both sides, and at the positions of the first side portion and the second side portion of each element region, the laminated block is cut so that the fourth sealing portion 134 is separated to both sides. Thereby, it is possible to singulate into an element laminate in which the first side portion and the second side portion are insulated by the sealing portion. In the cutting of the laminated block, for example, methods such as cutting using a dicing saw, a cutting blade, laser processing, and scribing can be applied. Additionally, in the case where the first sheet and the second sheet are laminated on a substrate including glass epoxy resin or the like, in order to reliably cut the second sheet which is a metal foil, it is preferable to cut the substrate to the semi-cut position. Additionally, by performing semi-cutting, it becomes a state where a stepped shape is generated from the first side portion and the second side portion of each element region to the substrate, and a part of the fourth sealing portion 134 fills the stepped shape.

[0268] Figure 21A FIG. is a perspective view schematically showing an example of the singulated element laminate. Figure 21B is Figure 21A a perspective view of a part of the element laminate shown in FIG. after being disassembled and enlarged.

[0269] The Figure 20AThe stacked block 40b shown is cut at the positions of the first end portion and the second end portion of each element region, and is also cut at the positions of the first side portion and the second side portion of each element region, whereby the Figure 21A element laminate 100 shown can be obtained. At this time, as Figure 21A and Figure 21B shown, the stacked block 40b is cut such that the cut side surfaces that appear by cutting at the positions of the first side portion and the second side portion are formed by the fourth sealing portion 134.

[0270] (H) Step of forming the first external electrode and the second external electrode

[0271] For the obtained element laminate, the first external electrode is formed on the first end face, and the second external electrode is formed on the second end face. Through the above, a solid electrolytic capacitor can be obtained.

[0272] Figure 1 The solid electrolytic capacitor 1 shown comprises Figure 17 the element laminate 100 shown, the first external electrode 141 provided on the first end face E101 of the element laminate 100, and the second external electrode 142 provided on the second end face E102 of the element laminate 100. The first external electrode 141 is connected to the metal foil 21 exposed on the first end face E101, and the second external electrode 142 is connected to the valve-acting metal substrate 11 exposed on the second end face E102.

[0273] The first external electrode and the second external electrode can be formed, for example, by plating, sputtering, dip coating, printing, etc. In the case of plating, a Zn·Ag·Ni layer, an Ag·Ni layer, a Ni layer, a Zn·Ni·Au layer, a Ni·Au layer, a Zn·Ni·Cu layer, a Ni·Cu layer, etc. can be used as the plating layer. It is preferable to further form a plating layer, for example, in the order of a Cu plating layer, a Ni plating layer, and a Sn plating layer (or except for a part) on these plating layers.

[0274] (Second Embodiment)

[0275] [Solid Electrolytic Capacitor]

[0276] The solid electrolytic capacitor according to the second embodiment of the present utility model is substantially the same as the solid electrolytic capacitor according to the first embodiment of the present utility model, except that a conductive layer is not provided between the solid electrolyte layer and the metal foil.

[0277] That is, the solid electrolytic capacitor according to this embodiment has the same as Figures 1 - 8The solid electrolytic capacitor 1 shown has the same structure. However, in order to reduce costs and simplify the process, the valve-acting metal substrate 11 and the metal foil 21 are connected without passing through a conductor layer other than the solid electrolyte layer 13. In this case, they can also be connected via a conductive adhesive layer (for example, a solid electrolyte layer containing an adhesive) provided on the solid electrolyte layer 13.

[0278] [Method for manufacturing a solid electrolytic capacitor]

[0279] Hereinafter, an example of the method for manufacturing a solid electrolytic capacitor according to the present embodiment will be described for each process.

[0280] (A) Process of preparing the first sheet

[0281] First, as Figure 9A and Figure 9B shown, the first sheet is prepared in the same manner as in the first embodiment. However, the solid electrolyte layer 13 is preferably formed thicker than in the first embodiment.

[0282] (B) Process of preparing the second sheet

[0283] In addition, as Figure 10A and Figure 10B shown, the second sheet is prepared in the same manner as in the first embodiment.

[0284] (E) Process of manufacturing the laminated sheet

[0285] In the same manner as in the first embodiment, a laminated sheet is manufactured by laminating the first sheet and the second sheet such that the first ends and the second ends of the respective element regions face each other. In the obtained laminated sheet, the first through-hole and the third through-hole, and the second through-hole and the fourth through-hole communicate with each other in the lamination direction.

[0286] Preferably, the second through-hole and the third through-hole linearly communicate with each other from the first main surface to the second main surface of the laminated sheet.

[0287] When laminating the first sheet and the second sheet, the valve-acting metal substrate and the metal foil are connected without passing through a conductor layer other than the solid electrolyte layer. In addition, in this case, the valve-acting metal substrate and the metal foil can also be connected via a conductive adhesive layer (for example, a solid electrolyte layer containing an adhesive) provided on the solid electrolyte layer.

[0288] In addition, for portions where the solid electrolyte layer or the conductive adhesive layer is not provided, the valve-acting metal substrate and the metal foil are connected via an adhesive resin.

[0289] Figure 22A is a perspective view schematically showing an example of the first sheet provided with the adhesive resin. Figure 22Bis Figure 22A A perspective view obtained by magnifying a part of the first sheet shown in the figure.

[0290] In Figure 22A and Figure 22B as in the first embodiment, on the mask layer 14 of the first sheet 10 shown in Figure 9A and Figure 9B a bonding resin (adhesive layer) 15 before curing or hardening is provided.

[0291] When laminating the first sheet and the second sheet, it is preferable to place the metal foil in a state where the layer located below the metal foil has adhesiveness. Since the solid electrolyte layer before drying is in a state having adhesiveness, it is suitable for directly placing the metal foil. In this case, it is preferable to form the solid electrolyte layer thicker than in the first embodiment. On the other hand, when the solid electrolyte layer as the layer located below the metal foil is dried, it becomes difficult to bond the metal foil, and thus it is preferable to place the metal foil on the basis of providing a conductive adhesive layer (for example, a solid electrolyte layer containing an adhesive).

[0292] Figure 23A is a perspective view schematically showing an example of the state before laminating the first sheet and the second sheet. Figure 23B is a perspective view schematically showing an example of laminating sheets.

[0293] As Figure 23A shown, as in the first embodiment, by alternately laminating the first sheet 10 and the second sheet 20 and curing or hardening the bonding resin 15, the laminated sheet 30 shown in Figure 23B can be obtained. However, in the present embodiment, the solid electrolyte layer of the first sheet 10 and the metal foil of the second sheet 20 are directly connected or connected via a conductive adhesive layer provided on the solid electrolyte layer.

[0294] (F) Step of manufacturing a laminated block

[0295] As in the first embodiment, from at least one main surface side of the obtained laminated sheet, a sealing material is filled into the first through hole and the third through hole, and the second through hole and the fourth through hole, respectively, thereby manufacturing a laminated block.

[0296] Figure 24A is a perspective view schematically showing an example of the laminated block. Figure 24B is Figure 24A a perspective view obtained by decomposing and magnifying a part of the laminated block shown in the figure.

[0297] As in the first embodiment, in Figure 24AIn the stacked block 40 shown, by filling the first through-hole and the third through-hole, and the second through-hole and the fourth through-hole with a sealing material respectively, as Figure 24B shown, a first sealing portion 131 that fills the first through-hole H1 and the third through-hole H3, and a second sealing portion 132 that fills the second through-hole H2 and the fourth through-hole H4 are formed. However, different from the first embodiment, a conductor layer is not provided on the first sheet 10. In addition, as Figure 24A shown, the stacked block 40 further includes a third sealing portion 133 that covers each main surface.

[0298] (G) Step of manufacturing a plurality of element stacked bodies by cutting the stacked block

[0299] Next, in the same manner as in the first embodiment, a plurality of element stacked bodies are manufactured by cutting the stacked block at the positions of the first end portion and the second end portion in each element region, and by cutting the stacked block at the positions of the first side portion and the second side portion in each element region.

[0300] (H) Step of forming the first external electrode and the second external electrode

[0301] For the obtained element stacked body, in the same manner as in the first embodiment, the first external electrode is formed on the first end surface, and the second external electrode is formed on the second end surface. Through the above, a solid electrolytic capacitor according to the second embodiment can be obtained.

[0302] In this specification, the following content is disclosed.

[0303] <1>

[0304] A solid electrolytic capacitor includes an element stacked body, a first external electrode, and a second external electrode, wherein,

[0305] in the element stacked body, a first layer and a second layer are stacked via an adhesive resin,

[0306] the first layer includes a valve action metal substrate having a dielectric layer formed on the surface and a solid electrolyte layer provided on the dielectric layer,

[0307] the second layer includes a metal foil,

[0308] and, in the element stacked body, the metal foil and the first sealing portion are exposed on the first end surface among the first end surface and the second end surface that face each other in the length direction, and the valve action metal substrate and the second sealing portion are exposed on the second end surface,

[0309] the first external electrode is provided on the first end surface of the element stacked body and is connected to the metal foil,

[0310] The second external electrode is provided on the second end face of the element laminate and is connected to the valve-acting metal substrate.

[0311] The first sealing portion has a first columnar portion penetrating the metal foil in the stacking direction and a first strip portion provided between the metal foils and connecting between the first columnar portions.

[0312] The second sealing portion has a second columnar portion penetrating the valve-acting metal substrate in the stacking direction and a second strip portion provided between the valve-acting metal substrates and connecting between the second columnar portions.

[0313] The adhesive resin has less filler than the first sealing portion and the second sealing portion, and in the interior of the element laminate, it exists in at least one of a first region between the metal foil and the first columnar portion, a second region between the valve-acting metal substrate and the first strip portion, a third region between the valve-acting metal substrate and the second columnar portion, and a fourth region between the metal foil and the second strip portion.

[0314] <2>

[0315] The solid electrolytic capacitor according to <1>, wherein

[0316] The adhesive resin exists in at least one of the first region and the third region in the interior of the element laminate.

[0317] <3>

[0318] The solid electrolytic capacitor according to <2>, wherein

[0319] The adhesive resin exists in the first region and the third region in the interior of the element laminate.

[0320] <4>

[0321] The solid electrolytic capacitor according to <2> or <3>, wherein

[0322] The adhesive resin covers at least one of the entire end face of the metal foil opposite to the first columnar portion and the entire end face of the valve-acting metal substrate opposite to the second columnar portion.

[0323] <5>

[0324] The solid electrolytic capacitor according to any one of <1> to <4>, wherein

[0325] The adhesive resin exposes from the interior of the element laminate to at least one of the first end face and the second end face.

[0326] <6>

[0327] The solid electrolytic capacitor according to <5>, wherein,

[0328] The adhesive resin exposes from the inside of the element laminate to the first end face and the second end face.

[0329] <7>

[0330] The solid electrolytic capacitor according to any one of <1> to <6>, wherein,

[0331] The adhesive resin does not contain a filler.

[0332] <8>

[0333] The solid electrolytic capacitor according to any one of <1> to <7>, wherein,

[0334] The Poisson's ratio of the adhesive resin is 0.3 or more.

Claims

1. A solid electrolytic capacitor includes an element laminate, a first external electrode, and a second external electrode, characterized in that: In the element laminate, a first layer and a second layer are laminated via an adhesive resin. The first layer includes a valve-acting metal substrate having a dielectric layer formed on its surface and a solid electrolyte layer provided on the dielectric layer. The second layer contains a metal foil. Moreover, in the element laminate, the metal foil and the first sealing portion are exposed at the first end face out of the first end face and the second end face that are opposite to each other in the length direction, and the valve-acting metal substrate and the second sealing portion are exposed at the second end face. The first external electrode is provided at the first end face of the element laminate and is connected to the metal foil. The second external electrode is provided at the second end face of the element laminate and is connected to the valve-acting metal substrate. The first sealing portion has a first columnar portion that penetrates the metal foil in the lamination direction and a first strip portion that is provided between the metal foils and connects between the first columnar portions. The second sealing portion has a second columnar portion that penetrates the valve-acting metal substrate in the lamination direction and a second strip portion that is provided between the valve-acting metal substrates and connects between the second columnar portions. The adhesive resin has less filler compared with the first sealing portion and the second sealing portion, and in the interior of the element laminate, it exists in at least one of a first region between the metal foil and the first columnar portion, a second region between the valve-acting metal substrate and the first strip portion, a third region between the valve-acting metal substrate and the second columnar portion, and a fourth region between the metal foil and the second strip portion.

2. The solid electrolytic capacitor according to claim 1, characterized in that: The adhesive resin exists in at least one of the first region and the third region in the interior of the element laminate.

3. The solid electrolytic capacitor according to claim 2, characterized in that: The adhesive resin exists in the first region and the third region in the interior of the element laminate.

4. The solid electrolytic capacitor according to claim 2 or 3, characterized in that: The adhesive resin covers at least one of the entire end face of the metal foil opposite to the first columnar portion and the entire end face of the valve-acting metal substrate opposite to the second columnar portion.

5. The solid electrolytic capacitor according to any one of claims 1 to 3, characterized in that: The adhesive resin is exposed from the interior of the element laminate to at least one of the first end face and the second end face.

6. The solid electrolytic capacitor according to claim 5, characterized in that: The adhesive resin is exposed from the interior of the element laminate to the first end face and the second end face.

7. The solid electrolytic capacitor according to any one of claims 1 to 3, characterized in that: The adhesive resin does not contain filler.

8. The solid electrolytic capacitor according to any one of claims 1 to 3, characterized in that: The Poisson's ratio of the adhesive resin is 0.3 or more.

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