Solid electrolytic capacitor element, solid electrolytic capacitor, and method for manufacturing solid electrolytic capacitor element

Abstract

A solid electrolytic capacitor element (1) is provided with: a valve action metal base (10) having a metal base layer (11), a porous layer (12) on the metal base layer (11), an anode terminal region (13), and a cathode formation region (14); a dielectric layer (20) provided on the surface of the porous layer (12) in the cathode formation region (14); a solid electrolyte layer (30) provided on the porous layer (12) with the dielectric layer (20) interposed therebetween in the cathode formation region (14); a conductive layer (40) formed on the solid electrolyte layer (30); and a mask (50) having a first portion (51) and a second portion (52), the first portion (51) partitioning the anode terminal region (13) and the cathode formation region (14) and being in contact with the porous layer (12) via the dielectric layer (20) or directly, the second portion (52) covering the solid electrolyte layer (30) provided on the porous layer (12), and the mask (50) not covering the conductive layer (40).

Description

Technical Field

[0001] The present invention relates to a solid electrolytic capacitor element, a solid electrolytic capacitor, and a method for manufacturing the solid electrolytic capacitor element. Background Art

[0002] Patent document 1 describes a solid electrolytic capacitor comprising a capacitor element, the capacitor element comprising: an anode foil having a first portion whose surface is etched and a second portion whose surface other than the first portion is not etched; a dielectric layer formed on the surface of the first portion of the anode foil; a solid electrolyte layer formed on the surface of the dielectric layer; and a cathode lead layer formed on a portion of the surface of the solid electrolyte layer, wherein a boundary between the first portion and the second portion and the vicinity of the boundary are covered by an insulating protective layer together with an end portion of the cathode lead layer and an end portion of the solid electrolyte layer.

[0003] Prior Art Literature

[0004] Patent Literature

[0005] Patent Document 1: International Publication No. 2017 / 154374 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] In the solid electrolytic capacitor described in Patent Document 1, although the stress applied to the vicinity of the insulating protective layer can be reduced, it is not possible to suppress the adverse conditions caused by the intrusion of the conductive paste when forming the cathode lead layer. In detail, the solid electrolyte layer near the boundary between the first part and the second part is thin and prone to defects. If the conductive paste used for the cathode lead layer intrudes into this part, it will cause poor leakage current and unstable quality. As a means to suppress this, the following countermeasures can be considered, namely, highly improving the processing accuracy of the conductive paste, or reducing the coating area of ​​the conductive paste, but the former will cause problems of increased equipment prices and management costs, and the latter will cause problems of sacrificing equivalent series resistance (ESR).

[0008] The present invention is completed to solve the above-mentioned problems, and its purpose is to provide a solid electrolytic capacitor element capable of suppressing leakage current defects. In addition, the purpose of the present invention is to provide a solid electrolytic capacitor having the above-mentioned solid electrolytic capacitor element. Furthermore, the purpose of the present invention is to provide a method for manufacturing a solid electrolytic capacitor element, which manufacturing method can realize a solid electrolytic capacitor element capable of suppressing leakage current defects.

[0009] Technical solutions to solve problems

[0010] The solid electrolytic capacitor element of the present invention comprises: a valve-acting metal substrate having a metal substrate layer and a porous layer on the metal substrate layer, and having an anode terminal region and a cathode forming region; a dielectric layer arranged on the surface of the porous layer in the cathode forming region; a solid electrolyte layer arranged on the porous layer in the cathode forming region via the dielectric layer; a conductive layer formed on the solid electrolyte layer; and a mask having a first part and a second part, wherein the first part divides the anode terminal region and the cathode forming region and contacts the porous layer via the dielectric layer or directly, and the second part covers the solid electrolyte layer arranged on the porous layer, and the mask does not cover the conductive layer.

[0011] The solid electrolytic capacitor of the present invention includes a plurality of solid electrolytic capacitor elements of the present invention.

[0012] The manufacturing method of the solid electrolytic capacitor element of the present invention comprises: a step of forming a first part of a mask for dividing an anode terminal region and a cathode forming region of the valve-acting metal substrate through a dielectric layer or directly on a porous layer of the valve-acting metal substrate; a step of forming a solid electrolyte layer on the porous layer in the cathode forming region through the dielectric layer after forming the first part; and a step of forming a second part of the mask for covering the solid electrolyte layer after forming the solid electrolyte layer.

[0013] Effects of the Invention

[0014] According to the present invention, a solid electrolytic capacitor element capable of suppressing leakage current defects can be provided. In addition, according to the present invention, a solid electrolytic capacitor having the above-mentioned solid electrolytic capacitor element can be provided. Furthermore, according to the present invention, a method for manufacturing a solid electrolytic capacitor element can be provided, which manufacturing method can realize a solid electrolytic capacitor element capable of suppressing leakage current defects. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a plan view schematically showing an example of a solid electrolytic capacitor element according to an embodiment of the present invention.

[0016] Figure 2 yes Figure 1 A cross-sectional view of the solid electrolytic capacitor element along line XX is shown.

[0017] Figure 3 Yes Figure 2 A cross-sectional view of an enlarged mask portion of a solid electrolytic capacitor element is shown.

[0018] Figure 4 is to Figure 2 The solid electrolytic capacitor element shown in different forms is an enlarged cross-sectional view of a mask portion of the solid electrolytic capacitor element.

[0019] Figure 5 This is a schematic diagram showing an example of the first step of forming a mask on the porous layer of the valve metal substrate.

[0020] Figure 6 It is a schematic diagram showing an example of the process of forming a solid electrolyte layer.

[0021] Figure 7 This is a schematic diagram showing an example of a step of immersing the valve metal substrate having the first portion on which the mask is formed in a treatment solution containing a solid electrolyte.

[0022] Figure 8 It is a schematic diagram showing an example of the process of forming the second part of the mask on the solid electrolyte layer.

[0023] Fig. 9 It is a perspective view schematically showing an example of a solid electrolytic capacitor according to an embodiment of the present invention.

[0024] Fig.10 yes Fig. 9 AA line cross-sectional view of the solid electrolytic capacitor shown.

[0025] Fig.11 It is a perspective view schematically showing another example of the solid electrolytic capacitor according to the embodiment of the present invention.

[0026] Fig.12 yes Fig.11 A cross-sectional view of the solid electrolytic capacitor along line BB is shown.

[0027] Fig.13 It is a perspective view schematically showing an example of the first portion of the exterior body, and shows a state in which a part of the through-hole is seen through.

[0028] Fig.14 This is a plan view schematically showing an example of a workpiece.

[0029] Fig.15 FIG. 1 is a diagram schematically showing an example of a process of preparing a stacked body in which a plurality of solid electrolytic capacitor elements are stacked on each other.

[0030] Fig.16 This is a diagram schematically showing an example of a step of attaching an adhesive sheet to the first portion of an exterior body.

[0031] Fig.17This is a diagram schematically showing an example of a process of supplying a conductive paste onto an adhesive sheet.

[0032] Fig.18 A is a diagram schematically showing an example of a process of inserting a stacked body into a through hole. Fig.18 B is a diagram schematically showing an example of a process of embedding the tip end portion of each element in the conductive paste. Fig.18 C is a diagram schematically showing an example of a process of filling the periphery of each element inserted into the through hole with a liquid material.

[0033] Fig.19 This is a diagram schematically showing an example of a step of cutting the first portion of the outer casing around the through hole.

[0034] Fig. 20 This is a graph showing the results of measuring leakage current of solid electrolytic capacitors of Examples and Comparative Examples. DETAILED DESCRIPTION

[0035] Hereinafter, the solid electrolytic capacitor element, the solid electrolytic capacitor, and the method for manufacturing the solid electrolytic capacitor element according to the present invention will be described.

[0036] However, the present invention is not limited to the following configurations, and can be applied with appropriate changes within the scope of the gist of the present invention. In addition, a configuration combining two or more of the preferred configurations described below is also the present invention.

[0037] [Solid electrolytic capacitor element]

[0038] Figure 1 It is a plan view schematically showing an example of a solid electrolytic capacitor element according to an embodiment of the present invention. Figure 2 yes Figure 1 A cross-sectional view of the solid electrolytic capacitor element along line XX is shown. Figure 3 Yes Figure 2 The solid electrolytic capacitor element shown in FIG. Figure 1 In FIG. 1 , the outer peripheries of the valve-acting metal substrate 10 and the solid electrolyte layer 30 covered by the conductive layer 40 are indicated by dotted lines.

[0039] Figure 1 to Figure 3 The solid electrolytic capacitor element 1 shown in the figure comprises: a valve-acting metal substrate 10 having a metal substrate layer 11 and a porous layer 12 on the metal substrate layer 11, and having an anode terminal region 13 and a cathode forming region 14; a dielectric layer 20 (see Figure 3 ,exist Figure 1 as well as Figure 2(not shown in the figure), which is arranged on the surface of the porous layer 12 in the cathode forming region 14; the solid electrolyte layer 30, which is arranged on the porous layer 12 through the dielectric layer 20 in the cathode forming region 14; the conductive layer 40, which is formed on the solid electrolyte layer 30; and the mask 50, which has a first part 51 and a second part 52.

[0040] The first portion 51 partitions the anode terminal region 13 and the cathode forming region 14 and contacts the porous layer 12 via the dielectric layer 20 . The second portion 52 covers the solid electrolyte layer 30 provided on the porous layer 12 . The mask 50 does not cover the conductive layer 40 .

[0041] As described above, the first portion 51 of the mask 50 divides the anode terminal region 13 and the cathode forming region 14 and contacts the porous layer 12 via the dielectric layer 20, and the second portion 52 of the mask 50 covers the solid electrolyte layer 30 provided on the porous layer 12. On the other hand, the mask 50 does not cover the conductive layer 40, so that the first portion 51 of the mask 50 can be formed first, and then the solid electrolyte layer 30 is formed in the cathode forming region 14, and then the second portion 52 of the mask 50 is formed, and then the conductive layer 40 is formed on the solid electrolyte layer 30. Therefore, even if the solid electrolyte layer 30 is thin near the first portion 51 of the mask 50 and a defect is generated, the thin film portion and the defect portion can be covered and protected by the second portion 52 of the mask 50 before the conductive layer 40 is formed. Therefore, even if the conductive layer 40 is formed later, the conductive layer 40 can be prevented from contacting the valve metal substrate 10 via the dielectric layer 20 at the thin film portion and the defect portion. As a result, the occurrence of leakage current failure due to the contact can be suppressed.

[0042] From the viewpoint of more effectively suppressing leakage current failure, it is preferred that Figure 3 As shown, the second portion 52 covers the solid electrolyte layer 30 from the end 51a of the cathode forming region 14 side of the first portion 51 to a point at least 50 μm (more preferably 100 μm, and further preferably 300 μm) away. That is, the width W of the second portion 52 when the end 51a of the cathode forming region 14 side of the first portion 51 is taken as the starting point is preferably 50 μm or more, more preferably 100 μm or more, and further preferably 300 μm or more.

[0043] From the viewpoint of reducing ESR, it is preferred that the second portion 52 does not cover the solid electrolyte layer 30 at a location exceeding 500 μm (more preferably 300 μm, and further preferably 100 μm) from the end 51 a on the cathode forming region 14 side of the first portion 51. That is, the width W of the second portion 52 when the end 51 a on the cathode forming region 14 side of the first portion 51 is taken as the starting point is preferably 500 μm or less, more preferably 300 μm or less, and further preferably 100 μm or less.

[0044] It is preferred that the second portion 52 covers at least a portion of the first portion 51. This can prevent a gap from being generated between the first portion 51 and the second portion 52, in which a thin film portion or a defective portion of the solid electrolyte layer 30 is exposed, and the conductive layer 40 is in contact with the valve metal substrate 10 via the dielectric layer 20 at the exposed thin film portion or defective portion. That is, leakage current failure can be more effectively suppressed.

[0045] like Figure 2 As shown, the thickness T1 of the solid electrolyte layer 30 near the first portion 51 may be smaller than the thickness T2 of the solid electrolyte layer 30 in the central portion of the solid electrolyte layer 30. In this case, as described above, the leakage current defect can be suppressed more effectively.

[0046] In this case, the thickness T1 of the solid electrolyte layer 30 may be smaller than the thickness T2 of the solid electrolyte layer 30 on each main surface side of the valve metal substrate 10. In addition, on each main surface side of the valve metal substrate 10, the thickness of the solid electrolyte layer 30 may gradually decrease from the vicinity of one end of the valve metal substrate 10 (the end farthest from the mask 50) toward the other end (the first portion 51 of the mask 50).

[0047] exist Figure 2 , the first part 51 and the second part 52 are shown to be provided on each main surface of the valve-acting metal substrate 10, but it is preferred that the first part 51 and the second part 52 are provided on at least one main surface of the valve-acting metal substrate 10. The valve-acting metal substrate 10 has a pair of main surfaces facing each other and a plurality of (usually 4) side surfaces connecting the pair of main surfaces, but since the area of ​​the pair of main surfaces is large, by providing the first part 51 and the second part 52 on at least one main surface (more preferably each main surface) of the valve-acting metal substrate 10, it is possible to more effectively suppress leakage current defects.

[0048] From the same viewpoint, the first portion 51 and the second portion 52 are preferably provided in an annular shape (e.g., a square annular shape) so as to surround the valve-acting metal substrate 10. That is, the first portion 51 and the second portion 52 are preferably provided on a pair of main surfaces and a pair of side surfaces of the valve-acting metal substrate 10.

[0049] In addition, Figure 3 , although the embodiment in which the first portion 51 of the mask 50 is in contact with the porous layer 12 via the dielectric layer 20 is shown, the first portion 51 of the mask 50 may be in direct contact with the porous layer 12 .

[0050] Figure 4 is to Figure 2 The solid electrolytic capacitor element shown in the figure is an enlarged cross-sectional view of a mask portion of the solid electrolytic capacitor element in different forms. Figure 4 , a mode in which the first portion 51 of the mask 50 is in direct contact with the porous layer 12 without interposing the dielectric layer 20 is shown. Figure 3 The mask portion shown is the same. The effect achieved by setting the mask 50 is the same as that achieved by Figure 2 as well as Figure 3 The same effect is exerted in the solid electrolytic capacitor element in the manner shown.

[0051] Hereinafter, each structure of the solid electrolytic capacitor element 1 will be described in detail.

[0052] The valve metal substrate 10 is a film (foil) having a quadrilateral shape in plan view, preferably a rectangular shape (long strip shape) having a pair of long sides and a pair of short sides in plan view. The valve metal substrate 10 functions as the anode 60 of the solid electrolytic capacitor element 1 .

[0053] In this specification, the term “viewed from above” means viewing from the normal direction of the main surface of the valve-acting metal substrate.

[0054] like Figure 3 as well as Figure 4 As shown, the valve-acting metal substrate 10 has a metal substrate layer 11 and a porous layer 12 provided with a plurality of recesses. Therefore, each main surface of the valve-acting metal substrate 10 becomes porous. As a result, the surface area of ​​the valve-acting metal substrate 10 becomes larger. In addition, it is not limited to the case where both main surfaces of the valve-acting metal substrate 10 are porous (porous layer 12), and it is also possible that only one of the two main surfaces of the valve-acting metal substrate 10 is porous (porous layer 12).

[0055] The metal matrix layer 11 is the core rod portion of the valve-acting metal matrix 10, such as Figure 2 As shown, its thickness is roughly constant.

[0056] The valve metal substrate 10 is made of a valve metal such as a single metal such as aluminum, tantalum, niobium, titanium, zirconium, or an alloy containing these metals. An oxide film may be formed on the surface of the valve metal.

[0057] In addition, the valve-acting metal substrate 10 only needs to be composed of a metal substrate layer and a porous layer arranged on at least one main surface of the metal substrate layer. It can appropriately adopt a valve-acting metal substrate in which the surface of a metal foil is etched, a valve-acting metal substrate in which a porous fine powder sintered body is formed on the surface of the metal foil, etc.

[0058] Here, the dielectric layer 20 is provided on the surface of the porous layer 12 of the valve metal substrate 10 (see Figure 3 ).exist Figure 3 In the embodiment shown in the figure, the dielectric layer 20 has only one end surface 11a of the metal base layer 11 (see Figure 2 ) is provided on the valve function metal substrate 10. In addition, Figure 4 In the embodiment shown, except for one end surface 11a of the metal base layer 11 (refer to Figure 2 ) and the entirety of the valve-acting metal substrate 10 except directly below the first portion 51 of the mask 50.

[0059] However, the dielectric layer 20 only needs to be provided on at least one of the two main surfaces of the valve-acting metal substrate 10 except at least the end surface 11 a .

[0060] The dielectric layer 20 is preferably composed of an oxide film provided on the surface of the porous layer 12 of the valve metal substrate 10. For example, the dielectric layer 20 is composed of aluminum oxide. As described later, the aluminum oxide is formed by anodizing the surface of the valve metal substrate.

[0061] The mask 50 is an insulating member provided along one side 10a (preferably a short side) of the valve-acting metal substrate 10, and separates the anode 60 and the cathode 70 of the solid electrolytic capacitor element 1, thereby ensuring insulation between the anode 60 and the cathode 70 of the solid electrolytic capacitor element 1. The valve-acting metal substrate 10 is divided into an anode terminal region 13 and a cathode forming region 14 by the first portion 51 of the mask 50. The mask 50 is provided in a straight line (extending in a strip shape) along the side 10a of the valve-acting metal substrate 10.

[0062] Here, the mask 50 (first portion 51) is arranged at a given interval from the side 10a of the valve metal substrate 10, but it can also be arranged near the side 10a. In this case, the end surface located at the side 10a of the valve metal substrate 10 becomes equivalent to the anode terminal area 13. In addition, the mask 50 is provided on a pair of main surfaces and a pair of side surfaces of the valve metal substrate 10 via the dielectric layer 20, but it can also be provided on at least one of the pair of main surfaces of the valve metal substrate 10 (however, it is the main surface provided with the dielectric layer 20) in the same way as the dielectric layer 20.

[0063] As described above, the mask 50 includes the first portion 51 that contacts the porous layer 12 via the dielectric layer 20, and the second portion 52 that covers the solid electrolyte layer 30 disposed on the porous layer 12. The first portion 51 mainly functions as an insulating mask that partitions the anode terminal region 13 and the cathode forming region 14 and prevents the solid electrolyte layer 30 from invading the anode terminal region 13, and the second portion 52 mainly functions as a protective mask that covers and protects the thin film portion and defect portion of the solid electrolyte layer 30. In addition, the coating area of ​​the conductive layer 40 is limited by the second portion 52. The second portion 52 covers only a portion of the solid electrolyte layer 30, and in particular, only a portion of the solid electrolyte layer 30 adjacent to the first portion 51.

[0064] like Figure 3 as well as Figure 4 As shown, the first portion 51 of the mask 50 is preferably provided to fill a plurality of pores (recesses) of the valve-acting metal substrate 10 (porous layer 12). However, as long as a portion of the outer surface of the dielectric layer 20 is covered by the first portion 51 of the mask 50, there may be pores (recesses) of the porous layer 12 that are not filled by the first portion 51 of the mask 50.

[0065] In addition, the first portion 51 of the mask 50 is continuously present from the portion filled in the pores of the porous layer 12 toward the opposite side of the metal base layer 11, and the first portion 51 of the mask 50 and the outermost surface 12a of the porous layer 12 (the surface that appears on the outermost side of the porous layer 12, see Figure 3 as well as Figure 4 However, when there are a plurality of pores of the porous layer 12 on the metal base layer 11 side that are not filled with the first portion 51 of the mask 50, the solid electrolyte layer 30 may be filled in these pores.

[0066] like Figure 3 as well as Figure 4 As shown, the second portion 52 of the mask 50 further covers the solid electrolyte layer 30 covering the outermost surface 12a of the porous layer 12. That is, the solid electrolyte exists in a layer between the second portion 52 of the mask 50 and the outermost surface 12a of the porous layer 12, and the second portion 52 of the mask 50 is not filled into the pores (recesses) of the valve metal substrate 10 (porous layer 12).

[0067] The mask 50 (the first portion 51 and the second portion 52) is made of an insulating material. For example, the mask 50 is formed by applying a mask material such as a composition containing an insulating resin. Examples of the insulating resin include polyphenylsulfone (PPS), polyethersulfone (PES), cyanate resin, fluororesin (tetrafluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, etc.), a composition containing a soluble polyimide siloxane and an epoxy resin, a polyimide resin, a polyamide-imide resin, and derivatives or precursors thereof.

[0068] The first portion 51 and the second portion 52 of the mask 50 may be formed of the same insulating material or may be formed of different insulating materials. In the former case, there may be no gap between the first portion 51 and the second portion 52. Figure 3 as well as Figure 4 In this case, the portion that contacts the porous layer 12 via the dielectric layer 20 or directly is referred to as the first portion 51 , and the portion that covers the solid electrolyte layer 30 provided on the porous layer 12 is referred to as the second portion 52 .

[0069] The mask material can be applied by, for example, screen printing, roller transfer, dispenser, inkjet printing, or the like.

[0070] The solid electrolytic capacitor element 1 includes a solid electrolyte layer 30 disposed on a dielectric layer 20 and a conductive layer 40 disposed on the solid electrolyte layer 30, which function as a cathode 70 of the solid electrolytic capacitor element 1. The cathode 70 is disposed on the dielectric layer 20 in the cathode forming region 14 of the valve-acting metal substrate 10 partitioned by the first portion 51 of the mask 50.

[0071] The solid electrolyte layer 30 is disposed on the dielectric layer 20. Figure 3 as well as Figure 4 As shown, the solid electrolyte layer 30 is preferably provided to fill the plurality of pores (recesses) of the valve-acting metal substrate 10 (porous layer 12). However, as long as a portion of the outer surface of the dielectric layer 20 is covered by the solid electrolyte layer 30, there may be pores (recesses) of the porous layer 12 that are not filled with the solid electrolyte layer 30.

[0072] The solid electrolyte layer 30 is provided on the dielectric layer 20 in the cathode forming region 14 of the valve acting metal substrate 10 partitioned by the first portion 51 of the mask 50 .

[0073] As a material constituting the solid electrolyte layer 30, for example, conductive polymers such as polypyrrole, polythiophene, and polyaniline can be used. Among them, polythiophenes are preferred, and poly (3,4-ethylenedioxythiophene) called PEDOT is particularly preferred. In addition, the conductive polymers may also contain a dopant such as polystyrene sulfonic acid (PSS).

[0074] The solid electrolyte layer 30 is formed, for example, by a method of forming a polymer film of a conductive polymer such as poly(3,4-ethylenedioxythiophene) on the surface of the dielectric layer 20 using a liquid containing a polymerizable monomer such as 3,4-ethylenedioxythiophene, or by a method of applying a dispersion of a conductive polymer such as poly(3,4-ethylenedioxythiophene) on the surface of the dielectric layer 20 and drying it.

[0075] In addition, it is preferred that an outer layer covering the entire dielectric layer 20 is formed after forming an inner layer that fills the pores (recesses) of the valve-acting metal substrate 10. The inner layer can be formed, for example, by dipping, electrolytic polymerization, sponge transfer, screen printing, dispenser, inkjet printing, etc. Similarly, the outer layer can be formed, for example, by dipping, electrolytic polymerization, sponge transfer, screen printing, dispenser, inkjet printing, etc.

[0076] The conductive layer 40 is provided on the solid electrolyte layer 30. The conductive layer 40 covers substantially the entire region of the solid electrolyte layer 30 except for the region covered by the second portion 52 of the mask 50, and is in contact with the second portion 52 of the mask 50. In addition, the conductive layer 40 may be arranged to cover at least a portion of the second portion 52 of the mask 50, or may be arranged in front of the second portion 52 of the mask 50 without being in contact with the second portion 52 of the mask 50. The conductive layer 40 has a substantially constant thickness.

[0077] The conductive layer 40 includes, for example, a carbon layer or a cathode conductor layer. Alternatively, the conductive layer 40 may be a composite layer in which a cathode conductor layer is provided on the outer surface of a carbon layer, or a mixed layer including carbon and cathode conductor layer materials.

[0078] The carbon layer is formed, for example, by applying a carbon paste containing carbon particles and a resin to the surface of the solid electrolyte layer 30 and drying the paste.

[0079] The carbon paste can be applied by, for example, dipping, sponge transfer, screen printing, spraying, dispenser, inkjet printing, or the like.

[0080] The cathode conductor layer is formed, for example, by applying a conductive paste containing metal particles such as gold, silver, copper, platinum, and resin to the surface of the solid electrolyte layer or the carbon layer and drying it. The cathode conductor layer is preferably a silver layer.

[0081] The conductive paste can be applied by, for example, dipping, sponge transfer, screen printing, spraying, dispenser, inkjet printing, or the like.

[0082] [Method for manufacturing solid electrolytic capacitor element]

[0083] Hereinafter, a method for manufacturing the solid electrolytic capacitor element 1 will be described. In the following example, a method for simultaneously manufacturing a plurality of solid electrolytic capacitor elements using a large valve-acting metal substrate will be described.

[0084] Figure 5 This is a schematic diagram showing an example of the first step of forming a mask on the porous layer of the valve metal substrate.

[0085] like Figure 5 As shown, a first portion 51 of a mask 50 for partitioning an anode terminal region 13 and a cathode forming region 14 of the valve acting metal substrate 10A is formed on a porous layer (not shown) of the valve acting metal substrate 10A via a dielectric layer (not shown).

[0086] More specifically, first, the valve-acting metal substrate 10A having a metal substrate layer (not shown) and a porous layer on the metal substrate layer is cut by laser processing or punching, thereby processing it into a shape including a plurality of element portions 15 and support portions 16. Each element portion 15 is in a long strip shape and protrudes from the support portion 16.

[0087] Next, the first portion 51 of the mask 50 is formed on both main surfaces and both side surfaces of the element portion 15 so as to be along the short sides of each element portion 15 .

[0088] The first portion 51 of the mask 50 is formed by applying a mask material such as a composition containing an insulating resin by, for example, screen printing, roll transfer, dispenser, inkjet printing, etc. Examples of the insulating resin include polyphenylsulfone (PPS), polyethersulfone (PES), cyanate resin, fluororesin (tetrafluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, etc.), a composition containing a soluble polyimide siloxane and an epoxy resin, a polyimide resin, a polyamide-imide resin, and derivatives or precursors thereof.

[0089] Then, the valve metal substrate 10A is anodized to form an oxide film that becomes a dielectric layer on the surface of the valve metal substrate 10A (porous layer). At this time, an oxide film is also formed on the side of the element portion 15 cut by laser processing or punching processing. In the case of this process, the dielectric layer is not formed on the portion of the surface of the valve metal substrate 10A (porous layer) covered by the first portion 51 of the mask 50, so the first portion 51 of the mask 50 comes into direct contact with the porous layer without the dielectric layer.

[0090] Alternatively, a chemically formed foil on which an oxide of a valve metal has been formed may be used as the valve metal substrate 10A. In this case, the cut valve metal substrate 10A is anodized to form an oxide film on the side surface of the cut element portion 15. When a chemically formed foil is used as the valve metal substrate 10A, the first portion 51 of the mask 50 comes into contact with the porous layer via the dielectric layer.

[0091] Figure 6 It is a schematic diagram showing an example of the process of forming a solid electrolyte layer.

[0092] Figure 7 This is a schematic diagram showing an example of a step of immersing the valve metal substrate having the first portion on which the mask is formed in a treatment solution containing a solid electrolyte.

[0093] After forming the first portion 51, as Figure 6 As shown, in the cathode forming region 14 , a solid electrolyte layer 30 is formed on the porous layer via a dielectric layer.

[0094] In more detail, Figure 7 As shown, the element portion 15 is immersed in the treatment liquid 80 containing the solid electrolyte from the front end side until it contacts the first portion 51 of the mask 50, thereby impregnating the porous layer of the valve metal substrate 10A with the treatment liquid 80. In addition, the treatment liquid 80 is supplied to the treatment tank 85. After being immersed for a given time, the element portion 15 is pulled up from the treatment liquid 80 and dried at a given temperature for a given time. By repeating the immersion in the treatment liquid 80, pulling up, and drying a given number of times, the solid electrolyte layer 30 is formed.

[0095] As the treatment liquid 80 containing a solid electrolyte, for example, a dispersion of a conductive polymer such as polypyrrole, polythiophene, or polyaniline can be used. A conductive polymer film can be formed by attaching the dispersion of the conductive polymer to the outer surface of the dielectric layer 20 and drying it. Alternatively, as the treatment liquid 80 containing a solid electrolyte, a liquid containing a polymerizable monomer (for example, 3,4-ethylenedioxythiophene) and an oxidant can also be used. The liquid containing the polymerizable monomer can be attached to the outer surface of the dielectric layer 20, and a conductive polymer film can be formed by chemical polymerization. The conductive polymer film becomes the solid electrolyte layer 30.

[0096] Figure 8 It is a schematic diagram showing an example of the process of forming the second part of the mask on the solid electrolyte layer.

[0097] like Figure 8As shown, after forming the solid electrolyte layer 30, the second portion 52 of the mask 50 is formed to cover the solid electrolyte layer 30. More specifically, the second portion 52 of the mask 50 is formed on both main surfaces and both side surfaces of the element portion 15 so as to be along the first portion 51 of the mask 50.

[0098] By forming the second portion 52 of the mask 50, even if the solid electrolyte layer 30 is thin near the first portion 51 of the mask 50 and a defect occurs, the thin film portion and the defect portion can be covered and protected by the second portion 52 of the mask 50 before forming the conductive layer 40. Therefore, as described above, the occurrence of leakage current defects can be suppressed.

[0099] The second portion 52 of the mask 50 is formed by applying a mask material such as a composition containing an insulating resin by, for example, screen printing, roll transfer, dispenser, inkjet printing, etc. Examples of the insulating resin include polyphenylsulfone (PPS), polyethersulfone (PES), cyanate resin, fluororesin (tetrafluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, etc.), a composition containing a soluble polyimide siloxane and an epoxy resin, a polyimide resin, a polyamide-imide resin, and derivatives or precursors thereof.

[0100] Then, a carbon paste is applied to the surface of the solid electrolyte layer 30 and dried, thereby forming a carbon layer in the cathode forming region 14. For example, the carbon layer is formed by dipping the element portion 15 in the carbon paste, pulling it up, and drying it. In addition to the dipping method, for example, the carbon paste can be applied by sponge transfer, screen printing, spraying, dispenser, inkjet printing, etc. In addition, the carbon paste is a conductive paste containing carbon particles as a conductive component and a resin component such as an epoxy resin or a phenolic resin.

[0101] Then, a conductive paste is applied to the surface of the carbon layer and dried, thereby forming a cathode conductor layer in the cathode forming area 14. For example, the cathode conductor layer is formed by dipping the element part 15 in the conductive paste, pulling it up and drying it. In addition to this dipping method, for example, the conductive paste can also be applied by sponge transfer, screen printing, spraying, dispenser, inkjet printing, etc. In addition, as a conductive paste for forming a cathode conductor layer, for example, a conductive paste containing metal particles as a conductive component and a resin component such as an epoxy resin and a phenolic resin can be listed. As metal particles, for example, gold, silver, copper, platinum, etc. can be listed. Among them, as a conductive paste for forming a cathode conductor layer, a silver paste containing silver particles as a conductive component is particularly suitable.

[0102] Finally, the valve-acting metal substrate 10A is cut to separate the element portion 15 to form a long valve-acting metal substrate 10A.

[0103] Through the above steps, the solid electrolytic capacitor element 1 is obtained.

[0104] [Solid electrolytic capacitors]

[0105] Fig. 9 It is a perspective view schematically showing an example of a solid electrolytic capacitor according to an embodiment of the present invention.

[0106] exist Fig. 9 In the solid electrolytic capacitor 100A shown, a plurality of solid electrolytic capacitor elements 1 are sealed with a sealing material to form a sealed body 160 , and includes a lead frame 170 connected to the anode of the solid electrolytic capacitor element 1 and a lead frame 180 connected to the cathode of the solid electrolytic capacitor element 1 .

[0107] exist Fig. 9 as well as Fig.10 In FIG. 1 , the length direction (long dimension direction) of the solid electrolytic capacitor 100A is indicated by L, the width direction is indicated by W, and the height direction is indicated by T. Here, the length direction L, the width direction W, and the height direction T are orthogonal to each other.

[0108] The long dimension direction of the solid electrolytic capacitor is also the long dimension direction of the lead frame.

[0109] Fig.10 yes Fig. 9 AA line cross-sectional view of the solid electrolytic capacitor shown.

[0110] Fig.10 The solid electrolytic capacitor 100A shown includes the above-mentioned plurality of solid electrolytic capacitor elements 1, a lead frame 170 connected to a valve-acting metal substrate 10 functioning as an anode 60 of the solid electrolytic capacitor element 1, a lead frame 180 connected to a conductive layer 40 functioning as a cathode 70 of the solid electrolytic capacitor element 1, and a sealing body 160 formed of a sealing material.

[0111] The sealing body 160 (sealing material) seals the plurality of solid electrolytic capacitor elements 1 .

[0112] The sealing body 160 is formed so as to cover the entire solid electrolytic capacitor element 1 , a part of the lead frame 170 , and a part of the lead frame 180 . Examples of the material of the sealing body 160 (sealing material) include epoxy resin and the like.

[0113] As described above, the solid electrolytic capacitor element 1 includes a valve-acting metal substrate 10, a dielectric layer (not shown), a solid electrolyte layer 30, a conductive layer 40, and a mask 50. The valve-acting metal substrate 10 includes a metal substrate layer 11 and a porous layer 12 on the metal substrate layer 11, and includes an anode terminal region 13 and a cathode forming region 14. The mask 50 includes a first portion 51 that is in direct contact with the porous layer 12 via the dielectric layer or directly, and a second portion 52 that covers the solid electrolyte layer 30 provided on the porous layer 12, and the mask 50 does not cover the conductive layer 40.

[0114] On the anode terminal region 13 side, the valve-acting metal substrates 10 of the solid electrolytic capacitor elements 1 are gathered together by a lead frame 170 and led out of the sealing material (sealing body 160 ).

[0115] On the cathode forming region 14 side, the conductive layer 40 of each solid electrolytic capacitor element 1 is electrically connected to the lead frame 180 and is led out of the sealing material (sealing body 160 ).

[0116] Fig.11 It is a perspective view schematically showing another example of the solid electrolytic capacitor according to the embodiment of the present invention. Fig.12 yes Fig.11 A cross-sectional view of the solid electrolytic capacitor along line BB is shown.

[0117] exist Fig.11 as well as Fig.12 In FIG. 1 , the length direction (long dimension direction) of the solid electrolytic capacitor 100B and the body 110 is indicated by L, the width direction is indicated by W, and the height direction is indicated by T. Here, the length direction L, the width direction W, and the height direction T are orthogonal to each other.

[0118] Fig.11 as well as Fig.12 The solid electrolytic capacitor 100B shown has a substantially rectangular parallelepiped shape. The solid electrolytic capacitor 100B includes a body 110 , a first external electrode 130 , and a second external electrode 140 .

[0119] The main body 110 includes a solid electrolytic capacitor element 1 (hereinafter, sometimes simply referred to as “element 1”) and a stacked body 101 in which a plurality of elements 1 are stacked on each other. Furthermore, the main body 110 includes an exterior body 120 and a collector electrode 102 .

[0120] The number of elements 1 included in the stacked body 101 is not particularly limited as long as it is two or more, and can be appropriately set.

[0121] The body 110 has a substantially rectangular parallelepiped shape and has a first main surface 110a and a second main surface 110b facing each other in the height direction T, a first side surface 110c and a second side surface 110d facing each other in the width direction W, and a first end surface 110e and a second end surface 110f facing each other in the length direction L.

[0122] As described above, the body 110 has a substantially rectangular parallelepiped shape, but may also have rounded corners and ridges. The corners are where three faces of the body 110 intersect, and the ridges are where two faces of the body 110 intersect.

[0123] The first external electrode 130 is formed on the first end surface 110 e of the body 110 , and the second external electrode 140 is formed on the second end surface 110 f of the body 110 .

[0124] The plurality of elements 1 are arranged overlapping in the height direction T. The extending direction of each of the plurality of elements 1 is substantially parallel to the first main surface 110a and the second main surface 110b of the body 110. The elements 1 adjacent to each other in the height direction T may be bonded to each other via a conductive adhesive (not shown).

[0125] As described above, the solid electrolytic capacitor element 1 includes a valve-acting metal substrate 10, a dielectric layer (not shown), a solid electrolyte layer 30, a conductive layer 40, and a mask 50. The valve-acting metal substrate 10 includes a metal substrate layer 11 and a porous layer 12 on the metal substrate layer 11, and includes an anode terminal region 13 and a cathode forming region 14. The mask 50 includes a first portion 51 that is in direct contact with the porous layer 12 via the dielectric layer or directly, and a second portion 52 that covers the solid electrolyte layer 30 provided on the porous layer 12, and the mask 50 does not cover the conductive layer 40.

[0126] like Fig.12 As shown, the outer casing 120 seals the plurality of elements 1. That is, the stacked body 101 of the plurality of elements 1 is buried in the outer casing 120. In addition, the outer casing 120 seals the collector electrode 102. Furthermore, the outer casing 120 has a first portion 121 made of a first resin material and a second portion 122 made of a second resin material.

[0127] The first portion 121 is a tube structure (for example, a square tube structure) having a through hole 123, and a plurality of elements 1 (stacked body 101) are accommodated in the through hole 123. The second portion 122 exists in the through hole 123 accommodating the plurality of elements 1 (stacked body 101).

[0128] Here, the so-called “square tube structure” is a structure in which the outer peripheral surface of the tube structure includes four planes, and two adjacent planes among the four planes intersect each other (preferably orthogonal), and the shape of the through hole 123 is not particularly limited.

[0129] The second portion 122 is filled into the through hole 123 accommodating the plurality of elements 1 (the stacked body 101 ). That is, the second portion 122 is filled inside the first portion 121 and around the plurality of elements 1 (the stacked body 101 ).

[0130] Here, the state in which the second portion 122 is filled into the through hole 123 containing the plurality of elements 1 (the stacked body 101) may be that the second portion 122 completely fills the space inside the first portion 121 and around the plurality of elements 1 (the stacked body 101), or may not completely fill it. In the latter case, for example, a small amount of air bubbles may remain in the second portion 122, a small amount of gap may remain between the second portion 122 and the first portion 121, or a small amount of gap may remain between the second portion 122 and at least one element 1.

[0131] The first resin material may be the same material as the second resin material, but is preferably a material different from the second resin material.

[0132] As the first resin material of the first portion 121, a resin that can be injection molded is suitable, and specifically, thermoplastic resins such as PPS (polyphenylene sulfide), LCP (liquid crystal polymer), PBT (polybutylene terephthalate), polyimide, and polyamide are suitable. The first resin material may also contain fillers such as silica particles, alumina particles, and metal particles, and fibers such as ceramic fibers as reinforcing materials.

[0133] Thermosetting resins such as epoxy resin, silicone resin, and urethane resin are suitable as the second resin material of the second portion 122. The second resin material may contain fillers such as silica particles, alumina particles, and metal particles, and fibers such as ceramic fibers as reinforcement materials.

[0134] like Fig.12 As shown, the collector electrode 102 is electrically connected to the plurality of cathodes 70 of the plurality of elements 1. The collector electrode 102 is exposed at the first end surface 110e of the body 110 and is provided at least at a portion of the first end surface 110e side of the body 110. In addition, the collector electrode 102 is formed in a shape having a thickness from the first end surface 110e toward the inner side.

[0135] Moreover, if Fig.12 As shown, at least the portion of each cathode 70 on the first external electrode 130 side is buried in the collector electrode 102 , thereby ensuring electrical connection between each cathode 70 and the collector electrode 102 .

[0136] The collector electrode 102 is a composite material of a conductive component (conductive material) and a resin component (resin material). The conductive component preferably contains a metal single substance such as silver, copper, nickel, tin, or an alloy containing at least one of these metals as a main component. The resin component preferably contains an epoxy resin, a phenolic resin, or the like as a main component. The collector electrode 102 can be formed using a conductive paste such as a silver paste, for example.

[0137] like Fig.12 As shown, the first external electrode 130 is provided on the first end surface 110e of the body 110. Fig.11 In the embodiment, the first external electrode 130 is provided from the first end surface 110e of the body 110 across the first main surface 110a, the second main surface 110b, the first side surface 110c, and the second side surface 110d. The first external electrode 130 is electrically connected to the collector electrode 102 exposed from the body 110 at the first end surface 110e. That is, the first external electrode 130 is electrically connected to each cathode 70 via the collector electrode 102.

[0138] In addition, the collector electrode 102 is present in the through hole 123 that accommodates the plurality of elements 1 (the stacked body 101), and the collector electrode 102 and the first portion 121 of the outer package 120 form the first end surface 110e of the body 110, so the first external electrode 130 can be formed on the first end surface 110e. Therefore, the electrical connection between the first external electrode 130 and the collector electrode 102 becomes easy, and the first external electrode 130 can be formed with a thin thickness.

[0139] Specifically, the first external electrode 130 may include a so-called sputtered film formed by a sputtering method. Examples of the material of the sputtered film include Ni, Sn, Ag, Cu, and Ag.

[0140] In addition, the first external electrode 130 may include a so-called vapor-deposited film formed by a vapor deposition method. Examples of the material of the vapor-deposited film include Ni, Sn, Ag, and Cu.

[0141] As described above, the first external electrode 130 can be formed of a sputtered film and / or a vapor-deposited film, and therefore the film thickness of the first external electrode 130 may be thinner than the film thickness of the second external electrode 140. Specifically, the film thickness of the first external electrode 130 is preferably 1 μm or more and 100 μm or less, more preferably 5 μm or more and 50 μm or less, and further preferably 10 μm or more and 30 μm or less.

[0142] like Fig.12 As shown in FIG. 1 , the second external electrode 140 is provided on the second end surface 110f of the body 110. Fig.11In the embodiment, the second external electrode 140 is provided from the second end surface 110f of the body 110 across the first main surface 110a, the second main surface 110b, the first side surface 110c, and the second side surface 110d. The second external electrode 140 is electrically connected to the anode 60 of the element 1 exposed from the body 110 at the second end surface 110f. The second external electrode 140 may be directly connected to the anode 60 at the second end surface 110f of the body 110, or may be indirectly connected.

[0143] At least one of the first external electrode 130 and the second external electrode 140 may also include a resin electrode layer including a conductive component and a resin component. The conductive component preferably includes a metal single substance such as silver, copper, nickel, tin, or an alloy containing at least one of these metals as a main component. The resin component preferably includes an epoxy resin, a phenolic resin, or the like as a main component. The resin electrode layer can be formed using, for example, a conductive paste such as a silver paste.

[0144] At least one of the first external electrode 130 and the second external electrode 140 may have a so-called plated layer formed by a plating method. Examples of the plated layer include a zinc-silver-nickel layer, a silver-nickel layer, a nickel layer, a zinc-nickel-gold layer, a nickel-gold layer, a zinc-nickel-copper layer, and a nickel-copper layer. It is preferred that, for example, a copper plated layer, a nickel plated layer, and a tin plated layer are sequentially provided on these plated layers (or, except for a part of the plated layers).

[0145] At least one of the first external electrode 130 and the second external electrode 140 may also have a resin electrode layer and a plating layer at the same time. For example, the first external electrode 130 may have a resin electrode layer connected to the collector electrode 102 and an outer plating layer provided on the surface of the resin electrode layer. In addition, the first external electrode 130 may also have an inner plating layer connected to the collector electrode 102, a resin electrode layer provided to cover the inner plating layer, and an outer plating layer provided on the surface of the resin electrode layer. In addition, the second external electrode 140 may have a resin electrode layer connected to the anode 60 and an outer plating layer provided on the surface of the resin electrode layer. In addition, the second external electrode 140 may also have an inner plating layer connected to the anode 60, a resin electrode layer provided to cover the inner plating layer, and an outer plating layer provided on the surface of the resin electrode layer.

[0146] [Method for manufacturing solid electrolytic capacitor]

[0147] Fig. 9 as well as Fig.10The solid electrolytic capacitor 100A shown can be manufactured, for example, by connecting lead frames 170 and 180 to a plurality of solid electrolytic capacitor elements 1 and then sealing the peripheries of the plurality of solid electrolytic capacitor elements 1 with a sealing material by resin molding such as compression molding or transfer molding to form a sealed body 160 .

[0148] Fig.11 as well as Fig.12 The solid electrolytic capacitor 100B shown can be manufactured by the following method. In the following example, a method of simultaneously manufacturing a plurality of solid electrolytic capacitor elements using a large valve-acting metal substrate is described.

[0149] Fig.13 It is a perspective view schematically showing an example of the first portion of the exterior body, and shows a state in which a part of the through-hole is seen through.

[0150] First, if Fig.13 As shown, a first part 221 (a member of the first part 121 of the outer body 120) of the outer body 220 including the above-mentioned first resin material and having a plurality of through holes 223 is prepared. The first part 221 is a member in which a plurality of through holes 223 are respectively provided in the vertical and horizontal directions on a flat plate having a given thickness and having a rectangular shape in a plan view. Each through hole 223 is provided in a direction orthogonal to the main surface of the first part 221, and both ends thereof are open. The first part 221 can be manufactured by injection molding. As the first resin material used for the first part 221, a resin that can be injection molded is suitable, and specifically, thermoplastic resins such as PPS (polyphenylene sulfide), LCP (liquid crystal polymer), PBT (polybutylene terephthalate), polyimide, and polyamide are suitable. The first resin material may contain fillers such as silica particles, alumina particles, and metal particles, and fibers such as ceramic fibers as reinforcing materials. Each corner portion inside each through hole 223 of the first portion 221 may be rounded or corner-processed (formed with an inclined surface).

[0151] Next, the stacked body 101 is prepared.

[0152] Fig.14 This is a plan view schematically showing an example of a workpiece.

[0153] First, if Fig.14 As shown, a workpiece 210 is prepared in which element portions 212 (plural solid electrolytic capacitor elements 1) are connected in a strip shape at regular intervals to a strip-shaped holding portion 211. A mask 50 is formed on each element portion 212. The workpiece 210 can be manufactured by the method described in the above-mentioned method for manufacturing a solid electrolytic capacitor element.

[0154] Here, in the first portion 221 , substantially rectangular parallelepiped through holes 223 are formed in the same number and pitch as the elements 1 of the long workpiece 210 , and a plurality of rows of such through holes 223 are provided.

[0155] Fig.15 FIG. 1 is a diagram schematically showing an example of a process of preparing a stacked body in which a plurality of solid electrolytic capacitor elements are stacked on each other.

[0156] Next, if Fig.15 As shown, a plurality of workpieces 210 having a plurality of elements 1 formed thereon in a long strip are prepared, and a given number of workpieces 210 are bundled so that the plurality of elements 1 overlap each other and fixed by a clamp such as a clamping device (not shown). Thus, a plurality of overlapping bodies 101 are produced in which the plurality of elements 1 overlap each other. In addition, the plurality of overlapping bodies 101 are arranged in a row (in a direction opposite to the direction of the workpiece 210). Fig.15 Columns arranged in a direction perpendicular to the paper surface).

[0157] Fig.16 This is a diagram schematically showing an example of a step of attaching an adhesive sheet to the first portion of an exterior body.

[0158] Then, if Fig.16 As shown, an adhesive sheet 250 (hereinafter, sometimes simply referred to as "sheet 250") is adhered to the first portion 221 so as to close the first opening 223a of each through hole 223. That is, the adhesive sheet 250 is adhered to the entire surface of one side of the first portion 221 so as to close one side of each through hole 223. Thus, by peeling off the sheet 250 after sealing, the collector electrode 102 can be easily exposed on the first end surface 110e of the body 110.

[0159] In addition, each through hole 223 only needs to be in a state where the first opening 223 a (lower opening) is covered. Instead of attaching the adhesive sheet 250 , the first opening 223 a may be covered by placing the first portion 221 on a flat table, for example.

[0160] Fig.17 This is a diagram schematically showing an example of a process of supplying a conductive paste onto an adhesive sheet.

[0161] Then, if Fig.17As shown, in a state where the first opening 223a of each through hole 223 is covered with an adhesive sheet 250, a conductive paste 230 is supplied onto the sheet 250 from the second opening 223b (the opening on the upper side) of each through hole 223. As a result, the conductive paste 230 is applied to the sheet 250 in each through hole 223. As the conductive paste 230, for example, a conductive paste containing metal particles as a conductive component and a resin component such as an epoxy resin or a phenolic resin can be cited. As the metal particles, for example, silver, copper, nickel, tin, etc. can be cited. Among them, as the conductive paste 230, a silver paste containing silver particles as a conductive component is particularly suitable. In addition, regarding the supply of the conductive paste 230, for example, a dispenser or the like can be used.

[0162] Fig.18 A is a diagram schematically showing an example of a process of inserting a stacked body into a through hole. Fig.18 B is a diagram schematically showing an example of a process of embedding the tip end portion of each element in the conductive paste. Fig.18 C is a diagram schematically showing an example of a process of filling the periphery of each element inserted into the through hole with a liquid material.

[0163] Then, if Fig.18 As shown in A, the plurality of fixed workpieces 210 are moved relative to the first portion 221, and the stacked body 101 is inserted into the through-holes 223 in the same row from the second opening 223b.

[0164] In this way, by using a workpiece 210 in which a plurality of components 1 are connected in a long strip shape at fixed intervals in a retaining portion 211, the components 1 can be inserted into the first portion 221 in units of long strips, thereby significantly improving productivity compared to inserting the components 1 one by one or the overlapping bodies 101 one by one into the first portion 221.

[0165] At this time, if Fig.18 As shown in B, the conductive paste 230 is pressed and expanded by the front end of each element 1 (i.e., the front end of the cathode 70), so that the front end of the cathode 70 of each element 1 is buried in the conductive paste 230. That is, the conductive paste 230 is connected to all the elements 1.

[0166] Then, in a state where each cathode 70 is embedded, for example, the conductive paste 230 is heated on the sheet 250 to be cured. As a result, the collector electrode 102 is formed in a state where at least the tip of the cathode 70 of each element 1 is embedded in the collector electrode 102 (see Fig.12 ).

[0167] Next, if Fig.18As shown in C, the liquid material 222 is filled around each element 1 inserted into each through hole 223 (that is, the gap between adjacent elements 1 and the gap between the stack 101 and the first part 221). For example, the liquid material 222 is injected into each through hole 223 by a dispenser or the like, and vacuum degassing is performed, thereby filling the liquid material 222 around each element 1. Here, the liquid material 222 is also filled between adjacent masks 50, but when adjacent masks 50 are in contact with each other, the liquid material 222 may not be filled between them. In addition, heating may be performed during injection and vacuum degassing to reduce the viscosity of the liquid material 222. The liquid material 222 includes the above-mentioned second resin material (however, it is a liquid material before curing). As for the resin included in the liquid second resin material, thermosetting resins such as epoxy resins, silicone resins, and urethane resins are suitable. The liquid second resin material may contain fillers such as silica particles, alumina particles, and metal particles, and fibers such as ceramic fibers as reinforcing materials.

[0168] The viscosity of the liquid material 222 before solidification is preferably 100 Pa·s or less at 25°C. If the viscosity is 100 Pa·s or less, filling can be easily performed simply by degassing and heating with a vacuum heating device (oven), thereby improving productivity. The viscosity of the liquid material 222 before solidification is more preferably 30 Pa·s or less at 25°C, and further preferably 5 Pa·s or less.

[0169] In addition, there is no lower limit for the viscosity of the liquid material 222 before curing, but it is preferable that the viscosity is not too low so that the liquid material 222 does not leak from the gap between the first part 221 and the sheet 250 during the period from the filling of the liquid material 222 to the heating and curing. More specifically, the viscosity of the liquid material 222 before curing is usually 0.01 Pa·s or more, preferably 0.1 Pa·s or more, and more preferably 0.3 Pa·s or more at 25°C.

[0170] Then, the liquid material 222 filled in each through hole 223 is solidified. For example, the liquid material 222 is heated and solidified by a vacuum heating device to form the second portion 222a of the outer casing 220 (the portion that becomes the second portion 122 of the outer casing 120).

[0171] In addition, bubbles may slightly remain in the second portion 222a which is the solidified product of the liquid material 222. In addition, a slight gap may slightly remain between the second portion 222a and the first portion 221 and / or between the second portion 222a and at least one element 1.

[0172] Then, for the through holes 223 of other columns, the supply of the conductive paste 230, the insertion of the plurality of elements 1 (the stacked body 101), the solidification of the conductive paste 230, the filling of the liquid material 222, and the solidification of the liquid material 222 are performed for each column, so that the plurality of elements 1 (the stacked body 101) and the second part 222a are accommodated in all the through holes 223.

[0173] Next, after the liquid material 222 is solidified, the sheet 250 is peeled off from the first portion 221. The collector electrode 102 connected to each element 1 is exposed on the peeled surface, and the peeled surface becomes the first end surface 110e of the body 110. In addition, the end surface of at least one cathode 70 may be exposed on the peeled surface.

[0174] On the other hand, the upper part of the first part 221 contains unnecessary parts of each element 1, unnecessary parts of the liquid material 222, and furthermore, the holding part 211 of the workpiece 210. In addition, in order to make the height of the first part 221 the length in the long dimension direction of the small piece, it is necessary to adjust it to a given length. Therefore, first, along a given cutting line (for example, Fig.18 The unnecessary part of the upper part of the first part 221 is cut off by a grinder or the like. The surface exposed by cutting off the unnecessary part becomes the second end surface 110f of the body 110. The anode 60 (foil composed of a valve metal matrix) of each element 1 is exposed at the second end surface 110f.

[0175] Next, dicing is performed for individual chips.

[0176] Fig.19 This is a diagram schematically showing an example of a step of cutting the first portion of the outer casing around the through hole.

[0177] like Fig.19 As shown, the first part 221 is cut around each through hole 223. Thus, the first part 121 of the tube structure can be easily formed from the first part 221. For example, a predetermined cutting line (for example, Fig.19 single-dotted line in the figure).

[0178] Through the above, the main body 110 including the stacked body 101 of the element 1 is obtained.

[0179] Then, the body 110 may be subjected to drum grinding. Specifically, the body 110 may be sealed together with the grinding material in a drum tank, and the drum tank may be rotated to grind the body 110. Thus, the corners and ridges of the body 110 are rounded.

[0180] In addition, if necessary, metal particles (e.g., Cu particles) may be ejected toward the second end surface 110f (anode end surface) of the barrel-polished body 110 by aerosol deposition and caused to collide. Thus, a metal film (contact layer) may be formed on the anode 60 exposed on the second end surface 110f (anode end surface) of the body 110.

[0181] Next, the first external electrode 130 and the second external electrode 140 are formed on the first end face 110e (cathode end face) and the second end face 110f (anode end face) of the body 110, respectively. For example, a conductive paste is applied by screen printing and cured to form resin electrode layers as the first external electrode 130 and the second external electrode 140, respectively. As the conductive paste for forming the resin electrode layer, a silver paste containing silver particles as a conductive component is suitable. Then, a plated layer may be formed on the resin electrode layer by plating.

[0182] At this time, as the first external electrode 130 , a thin sputtered film and / or vapor-deposited film having a thickness of, for example, several μm may be formed by a sputtering method or a vapor deposition method.

[0183] The solid electrolytic capacitor 100B can be obtained by the above-described method.

[0184] In addition, the case where the collector electrode 102 is provided is described here, but the collector electrode 102 may not be provided and the cathode 70 of each solid electrolytic capacitor element 1 may be directly connected to the first external electrode 130. In this case, for example, after the adhesive sheet 250 is peeled off, the lower part of the first portion 221 to which the sheet 250 is adhered may be shaved off with a grinder or the like, thereby exposing each cathode 70 at the first end surface 110e (cathode end surface) of the body 110, and the first external electrode 130 may be formed on each cathode 70 exposed at the first end surface 110e.

[0185] In addition, in the case where the collector electrode 102 is not provided, the second part 222a of the outer casing 220 can also be implemented according to the following process. That is, first, the liquid material 222 is injected into each through hole 223 of the first part 221 by a dispenser or the like to fill it. Next, a plurality of solid electrolytic capacitor elements 1 (stacked body 101) are inserted into each through hole 223 filled with the liquid material 222, and the liquid material 222 is filled around each inserted element 1. For example, after the plurality of elements 1 are inserted, vacuum degassing is performed, thereby filling the liquid material 222 around each element 1. Then, the liquid material 222 filled in each through hole 223 is heated, for example, by a vacuum heating device, thereby solidifying it.

[0186] Furthermore, in the above-mentioned embodiments (particularly Fig.11 as well as Fig.12 ), the case where the outer casing 120 is composed of only two resin materials (i.e., the first part 121 and the second part 122) is described, but the outer casing 120 may also be composed of three resin materials. For example, one or more intermediate resin layers composed of resin materials may be provided between the first part and the second part of the outer casing. Such an intermediate resin layer may be formed, for example, in the following manner, that is, the second part for sealing the overlapping body of multiple solid electrolytic capacitor elements is formed in advance by transfer molding or the like with a size smaller than the through hole of the first part, and then the overlapping body of the solid electrolytic capacitor elements is inserted into the through hole of the first part for each second part, and then the gap between the second part and the first part is filled with liquid resin material and cured.

[0187] On the contrary, the outer casing 120 may be made of only one resin material. For example, the first part 121 may not be provided and only the second part 122 may be provided. Such a solid electrolytic capacitor can be manufactured, for example, by setting a cutting line inside each through hole 223 in a dicing process for singulation, and cutting and removing all of the first part 221.

[0188] Furthermore, in the above-mentioned embodiments (particularly Fig.11 as well as Fig.12 ) described the case where a substantially rectangular main body 110 is used, but Fig.11 as well as Fig.12 In the solid electrolytic capacitor 100B shown, the shape of the body is not particularly limited as long as it has a first end face and a second end face facing each other, and may be, for example, cylindrical in shape other than a substantially rectangular parallelepiped.

[0189] Furthermore, in the above-mentioned embodiments (particularly Figures 13 to 19 ) described the case where a plurality of main bodies 110 are simultaneously manufactured using the first part 221 having a plurality of through holes 223, but the main bodies may also be manufactured one by one using the first part of the outer body having only one through hole.

[0190] Example

[0191] Hereinafter, examples are shown which more specifically disclose the solid electrolytic capacitor element, the solid electrolytic capacitor, and the method for manufacturing the solid electrolytic capacitor of the present invention. However, the present invention is not limited to these examples.

[0192] (Example)

[0193] Made with Fig. 9 as well as Fig.10The solid electrolytic capacitor 100A shown is similar to a plurality of solid electrolytic capacitors. However, all of the solid electrolytic capacitors use a solid electrolytic capacitor in which a defect is generated in the solid electrolyte layer near the first portion of the mask.

[0194] (Comparative Example)

[0195] A plurality of solid electrolytic capacitors were produced in the same manner as in Example except that the second portion of the mask was not formed. For any of the solid electrolytic capacitors of Comparative Example, a solid electrolytic capacitor having a defect in the solid electrolyte layer near the first portion of the mask was used.

[0196] Fig. 20 is a graph showing the results of measuring leakage current of the solid electrolytic capacitors of the embodiment and the comparative example. Fig. 20 In the graph, the vertical axis shows the magnitude (logarithm) of the leakage current, and the horizontal axis shows the number of solid electrolytic capacitors showing the leakage current on the vertical axis.

[0197] like Fig. 20 As shown, in the embodiment having the mask having the first portion and the second portion, even if a defect occurs in the solid electrolyte layer, the leakage current can be made below the standard value (see the standard line in the figure), thereby preventing the occurrence of leakage current defects.

[0198] On the other hand, in the comparative example including the mask having only the first portion, a solid electrolytic capacitor having a leakage current exceeding the standard value (see the standard line in the figure) was produced.

[0199] In this specification, the following contents are disclosed.

[0200] <1>

[0201] A solid electrolytic capacitor element, comprising:

[0202] A valve-acting metal substrate having a metal substrate layer and a porous layer on the metal substrate layer, and having an anode terminal region and a cathode forming region;

[0203] a dielectric layer provided on the surface of the porous layer in the cathode forming region;

[0204] a solid electrolyte layer provided on the porous layer in the cathode forming region via the dielectric layer;

[0205] a conductive layer formed on the solid electrolyte layer; and

[0206] A mask having a first part and a second part,

[0207] The first portion divides the anode terminal region and the cathode forming region and is in contact with the porous layer via the dielectric layer or directly.

[0208] The second portion covers the solid electrolyte layer provided on the porous layer,

[0209] The mask does not cover the conductive layer.

[0210] <2>

[0211] according to <1> The solid electrolytic capacitor element, wherein:

[0212] The second portion covers the solid electrolyte layer from the end of the first portion on the cathode formation region side to a point at least 50 μm away.

[0213] <3>

[0214] according to <1> or <2> The solid electrolytic capacitor element, wherein:

[0215] The second portion does not cover the solid electrolyte layer at a location exceeding 500 μm from an end of the first portion on the cathode formation region side.

[0216] <4>

[0217] according to <1> to <3> The solid electrolytic capacitor element according to any one of claims , wherein:

[0218] The second portion covers at least a portion of the first portion.

[0219] <5>

[0220] according to <1> to <4> The solid electrolytic capacitor element according to any one of claims , wherein:

[0221] The thickness of the solid electrolyte layer near the first portion is smaller than the thickness of the solid electrolyte layer at a central portion of the solid electrolyte layer.

[0222] <6>

[0223] according to <1> to <5> The solid electrolytic capacitor element according to any one of claims , wherein:

[0224] The first portion and the second portion are provided on at least one main surface of the valve-acting metal substrate.

[0225] <7>

[0226] according to <6> The solid electrolytic capacitor element, wherein:

[0227] The first portion and the second portion are provided in an annular shape so as to surround the valve-acting metal substrate.

[0228] <8>

[0229] A solid electrolytic capacitor having multiple <1> to <7> A solid electrolytic capacitor element as described in any one of claims .

[0230] <9>

[0231] A method for manufacturing a solid electrolytic capacitor element, comprising:

[0232] a step of forming a first portion of a mask for partitioning an anode terminal region and a cathode forming region of the valve metal substrate through a dielectric layer or directly on the porous layer of the valve metal substrate;

[0233] After forming the first portion, forming a solid electrolyte layer on the porous layer via the dielectric layer in the cathode formation region; and

[0234] A step of forming a second portion of the mask covering the solid electrolyte layer after forming the solid electrolyte layer.

[0235] Description of Reference Numerals

[0236] 1: Solid electrolytic capacitor element;

[0237] 10, 10A: valve action metal substrate;

[0238] 10a: The edge of the valve metal substrate;

[0239] 11: metal substrate layer;

[0240] 11a: one end surface of the metal base layer;

[0241] 12: porous layer;

[0242] 12a: the outermost surface of the porous layer;

[0243] 13: anode terminal area;

[0244] 14: cathode formation area;

[0245] 15: Components;

[0246] 16: supporting part;

[0247] 20: dielectric layer;

[0248] 30: solid electrolyte layer;

[0249] 40: conductive layer;

[0250] 50: mask;

[0251] 51: Part 1 of the mask;

[0252] 51a: an end of the first portion of the mask on the cathode forming region side;

[0253] 52: Part 2 of the mask;

[0254] 60: anode;

[0255] 70: cathode;

[0256] 80: treatment liquid;

[0257] 85: Processing tank;

[0258] 100A, 100B: solid electrolytic capacitor;

[0259] 101: overlapping body;

[0260] 102: current collecting electrode;

[0261] 110: Ontology;

[0262] 110a: 1st main surface;

[0263] 110b: second main surface;

[0264] 110c: 1st side;

[0265] 110d: lateral side 2;

[0266] 110e: 1st end surface;

[0267] 110f: second end surface;

[0268] 120: Exterior body;

[0269] 121: Part 1 of the outer casing;

[0270] 122: Part 2 of the outer casing;

[0271] 123: through hole;

[0272] 130: first external electrode;

[0273] 140: second external electrode;

[0274] 160: sealing body;

[0275] 170, 180: lead frame;

[0276] 210: Artifacts;

[0277] 211: Maintenance department;

[0278] 212: Components;

[0279] 220: Exterior body;

[0280] 221: Part 1 of the outer body;

[0281] 222: Liquid material;

[0282] 222a: Part 2 of the outer casing;

[0283] 223: through hole;

[0284] 223a: Opening 1;

[0285] 223b: 2nd opening;

[0286] 230: conductive paste;

[0287] 250: Adhesive sheet;

[0288] W: width of the second part of the mask;

[0289] T1: thickness of the solid electrolyte layer near the first part of the mask;

[0290] T2: The thickness of the solid electrolyte layer at the central portion of the solid electrolyte layer.

Claims

1. A solid electrolytic capacitor element, comprising: A valve-acting metal substrate having a metal substrate layer and a porous layer on the metal substrate layer, and having an anode terminal region and a cathode forming region; a dielectric layer provided on the surface of the porous layer in the cathode forming region; a solid electrolyte layer provided on the porous layer in the cathode forming region via the dielectric layer; a conductive layer formed on the solid electrolyte layer; as well as A mask having a first part and a second part, The first portion divides the anode terminal region and the cathode forming region and is in contact with the porous layer via the dielectric layer or directly. The second portion covers the solid electrolyte layer provided on the porous layer, The mask does not cover the conductive layer.

2. The solid electrolytic capacitor element according to claim 1, wherein The second portion covers the solid electrolyte layer from the end of the first portion on the cathode formation region side to a point at least 50 μm away.

3. The solid electrolytic capacitor element according to claim 1 or 2, wherein: The second portion does not cover the solid electrolyte layer at a location exceeding 500 μm from an end of the first portion on the cathode formation region side.

4. The solid electrolytic capacitor element according to any one of claims 1 to 3, wherein: The second portion covers at least a portion of the first portion.

5. The solid electrolytic capacitor element according to any one of claims 1 to 4, wherein: The thickness of the solid electrolyte layer near the first portion is smaller than the thickness of the solid electrolyte layer at a central portion of the solid electrolyte layer.

6. The solid electrolytic capacitor element according to any one of claims 1 to 5, wherein: The first portion and the second portion are provided on at least one main surface of the valve-acting metal substrate.

7. The solid electrolytic capacitor element according to claim 6, wherein: The first portion and the second portion are provided in an annular shape so as to surround the valve-acting metal substrate. 8 . A solid electrolytic capacitor comprising a plurality of the solid electrolytic capacitor elements according to claim 1 .

9. A method for manufacturing a solid electrolytic capacitor element, comprising: a step of forming a first portion of a mask for partitioning an anode terminal region and a cathode forming region of the valve metal substrate through a dielectric layer or directly on the porous layer of the valve metal substrate; After forming the first portion, a step of forming a solid electrolyte layer on the porous layer via the dielectric layer in the cathode formation region; as well as A step of forming a second portion of the mask covering the solid electrolyte layer after forming the solid electrolyte layer.

Images