JP2013165204A - Solid electrolytic capacitor and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solid electrolytic capacitor which achieves a uniform thickness of a capacitor element, inhibits a leakage current, and enables thickness reduction, and to provide a manufacturing method of the solid electrolytic capacitor.SOLUTION: A conductive paste layer is composed of a first conductive paste layer 6 and a second conductive paste layer 16. The first conductive paste layer 6 is formed so that at least a part of an outer edge part of a graphite layer 5 at a major surface part of a cathode part 15 is exposed and at least a part of the graphite layer 5 at a side surface part is exposed. The second conductive paste layer 16 is formed on at least one of surfaces of the graphite layer 5 and the first conductive paste layer 6 at the side surface part.

Description

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

  Conventionally, solid electrolytic capacitors using tantalum, niobium, etc. as valve metals are small, have large capacitance, and have excellent frequency characteristics, so switching power supply circuits for driving devices that operate at high speeds such as CPUs Widely used in etc.

  In recent years, with the development of portable electronic devices, there has been an increasing demand for thinner and higher capacity solid electrolytic capacitors. Further, in order to cope with a reduction in price, a solid electrolytic capacitor in which a plurality of capacitor elements using etched aluminum foil or plate are stacked is used.

  An example of the structure of a conventional solid electrolytic capacitor will be described. 4A and 4B are diagrams for explaining the configuration of a conventional solid electrolytic capacitor. FIG. 4A is a schematic cross-sectional view of the capacitor element, FIG. 4B is a front view of the multilayer body of the capacitor element, and FIG. (C) is a schematic sectional drawing of a solid electrolytic capacitor, FIG.4 (d) is an AA sectional view taken on the line of a capacitor element.

  As shown in FIG. 4A, the capacitor element 100 is divided into an anode portion 130 and a cathode portion 140 by an insulating portion 125 made of an insulating resin. The cathode portion 140 includes a porous layer 126 formed by etching, and a dielectric layer (see FIG. 5) on the surface of a metal body 120 made of a valve action metal such as an aluminum foil having two main surface portions and a side surface in contact with these main surface portions. The solid electrolyte layer 121, the graphite layer 122, and the conductive paste layer 123 are sequentially provided on the surface of the dielectric layer. The anode part 130 includes a metal body core 127 from which the porous layer 126 of the metal body 120 is removed, and a spacer 124 made of 42 alloy or the like. The metal core 127 and the spacer 124 are electrically connected by welding or the like.

  As shown in FIG. 4B, in the multilayer body 210, in the plurality of capacitor elements 100, the anode portions 130 are electrically connected by welding or the like, and the cathode portions 140 are electrically connected to the main surface portion of the cathode portion 140. The adhesive 129 is applied and electrically connected. A side silver paste layer 128 is partially provided on the side surface of the laminate 210 in order to further reduce the equivalent series resistance (ESR).

  As shown in FIG. 4 (c), the laminate 210 includes a molded insulating resin in which a cathode portion 140 and an anode portion 130 are connected to an electrode terminal 131 provided on a substrate 145 with a conductive adhesive 129 or the like. The exterior 150 which consists of is provided, and the solid electrolytic capacitor 220 is obtained. An example of a solid electrolytic capacitor having such a configuration is described in Patent Document 1.

JP 2009-158692 A

  The conductive paste layer 123 constituting the outermost side of the cathode part 140 is usually provided using a silver paste or the like in order to reduce ESR. Conventionally, the conductive paste layer 123 is formed by dipping or the like in which the portion where the solid electrolyte layer is formed is directly immersed in the silver paste. However, it is easy to control the film thickness and shape of the silver paste. In some cases, screen printing is used at the stage of the capacitor element 100. The screen printing is generally performed using a screen plate having holes opened only in a portion where the silver paste or the like is to be printed, and a spatula (squeegee) such as urethane rubber that extrudes the silver paste or the like.

  An example of the manufacturing process of the conductive paste layer 123 by screen printing will be described. First, the opening of the screen plate is disposed in the cathode portion of the capacitor element, and silver paste is supplied to the screen plate. Then, while pressing the squeegee from above the screen plate, it is moved in a predetermined direction to fill the opening with silver paste, and the silver paste is further discharged from the opening to print the silver paste on the cathode part of the capacitor element ( And a conductive paste layer 123 is formed. Normally, the squeegee starts to move from the insulating portion 125 side, and stops and rises after passing through the end portion of the cathode portion 140. In accordance with this, the screen plate is also placed or separated from the capacitor element. In screen printing, by applying a silver paste using a screen plate having an opening larger than the area of the main surface portion of the cathode portion, the silver paste can be simultaneously applied to the side portion in contact with the main surface portion of the cathode portion, There is an advantage that the conductive paste layer 123 in the side surface portion can be formed.

  However, in the formation of the conductive paste layer using the screen printing described above, when the silver paste accumulated in the gap between the cathode portion 140 and the opening does not fall down to the side surface, the pressing by the squeegee is finished and the screen plate is released. It may remain on the main surface portion of the cathode portion 140. In this case, as shown in FIG. 4D, the conductive paste layer 123 may swell at the outer edge portion of the main surface portion of the cathode portion 140, and there is a problem that the thickness of the capacitor element 100 becomes uneven. In particular, in the vicinity of the corner portion of the cathode portion 140 where the movement of the squeegee stops and rises on the main surface portion, the swell of the conductive paste layer 123 becomes remarkable and the thickness of the capacitor element 100 becomes uneven, which is sufficient for thinning. There is a problem that it cannot respond.

  In addition, when a laminated body is formed by laminating capacitor elements having non-uniform thicknesses, the cathode part is distorted by the molding pressure when the exterior is provided, the dielectric layer is damaged, and the leakage current (LC) increases. There is also.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a solid electrolytic capacitor capable of making the thickness of the capacitor element uniform, suppressing LC, and capable of reducing the thickness, and a method for manufacturing the same. It is.

  The present invention relates to a solid electrolytic capacitor and a method of manufacturing the same, wherein the conductive paste layer is a first conductive paste layer and a second conductive paste layer, and the first conductive paste is an outer edge of the graphite layer in the main surface portion. At least part of the portion is exposed and at least part of the graphite layer on the side surface is exposed, and the second conductive paste layer is at least of the graphite layer on the side surface and the first conductive paste layer. By forming on one surface, the thickness of the capacitor element can be made uniform, LC can be suppressed, and the thickness can be reduced.

  That is, the solid electrolytic capacitor of the present invention is divided into an anode part and a cathode part by an insulating part, and the cathode part is flat and has a surface of a valve metal having two main surface parts and a side part in contact with the main surface part. A porous layer, and a dielectric layer, a solid electrolyte layer, a graphite layer, and a conductive paste layer are sequentially provided on the surface of the porous layer, and the anode portion is the valve derived from the insulating portion. A capacitor element made of a working metal, and a plurality of the capacitor elements are stacked, and the anode part and the cathode part are electrically connected to electrode terminals provided on a substrate, and the entire surface is made of an insulating material. A solid electrolytic capacitor having an outer covering, wherein the conductive paste layer includes a first conductive paste layer and a second conductive paste layer, and the first conductive paste layer includes the main surface portion. And at least part of the outer edge of the graphite layer is exposed, and at least part of the graphite layer in the side part is exposed, and the second conductive paste layer is in the side part, It is formed on at least one surface of the graphite layer and the first conductive paste layer.

  Further, the solid electrolytic capacitor of the present invention is characterized in that the first conductive paste layer is formed such that corner portions of the graphite layer in the main surface portion serving as end portions of the capacitor element are exposed. To do.

  In the solid electrolytic capacitor of the present invention, the first conductive paste layer and the second conductive paste layer are made of at least one selected from silver, copper, or a mixture thereof, and a conductive paste made of a resin. Preferably it is formed.

  The solid electrolytic capacitor manufacturing method of the present invention is divided into an anode part and a cathode part by an insulating part, and the cathode part is a flat plate-shaped valve action metal having two principal surface parts and a side part in contact with the principal surface part. A porous layer is provided on the surface, and a dielectric layer, a solid electrolyte layer, a graphite layer, and a conductive paste layer are sequentially provided on the surface of the porous layer, and the anode portion is derived from the insulating portion. A method for producing a solid electrolytic capacitor comprising a step of laminating a plurality of capacitor elements made of a valve metal, wherein the conductive paste layer comprises a first conductive paste layer and a second conductive paste layer, In the first conductive paste layer, at least a part of the outer edge part of the graphite layer in the main surface part is exposed, and at least a part of the graphite layer in the side part is exposed. Forming by using screen printing, and forming the second conductive paste layer on at least one surface of the graphite layer and the first conductive paste layer in the side surface portion, And a step of electrically connecting the anode part and the cathode part to electrode terminals provided on a substrate and providing an exterior covering the entire surface with an insulating material.

  Further, in the method for producing a solid electrolytic capacitor of the present invention, the first conductive paste layer is applied from the direction of the insulating portion to the end portion of the cathode portion using screen printing, and the capacitor element A step of exposing the corner portion of the graphite layer in the main surface portion which is an end portion of the graphite layer.

  Moreover, the method for producing a solid electrolytic capacitor of the present invention comprises forming a first conductive paste layer and a second conductive paste layer from at least one selected from silver or copper or a mixture thereof and a resin. A conductive paste is used.

  According to the present invention, the conductive paste includes the first conductive paste and the second conductive paste, and the first conductive paste exposes at least a part of the outer edge portion of the graphite layer in the main surface portion. And the second conductive paste is formed on at least one surface of the graphite layer and the first conductive paste in the side surface portion so as to expose at least a part of the graphite layer in the side surface portion. As a result, the thickness of the capacitor element can be made uniform, and it is possible to provide a solid electrolytic capacitor and a method for manufacturing the same corresponding to a reduction in thickness.

  In addition, according to the present invention, since the thickness of the capacitor element can be made uniform, it is possible to provide a solid electrolytic capacitor in which LC is suppressed and a method for manufacturing the same.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure explaining the structure of Embodiment 1 of the solid electrolytic capacitor of this invention, Fig.1 (a) is sectional drawing of a capacitor | condenser element, FIG.1 (b) is a top view of a capacitor | condenser element, FIG.1 (c) ) Is a front view of a laminate of solid electrolytic capacitors, and FIG. 1D is a cross-sectional view of the solid electrolytic capacitors. It is a figure explaining the structure of Embodiment 2 of the solid electrolytic capacitor of this invention, Fig.2 (a) is a top view of a capacitor | condenser element, FIG.2 (b) is a front view of the laminated body of a solid electrolytic capacitor. It is a figure explaining the structure of Embodiment 3 of the solid electrolytic capacitor of this invention, Fig.3 (a) is a top view of a capacitor | condenser element, FIG.3 (b) is a front view of the laminated body of a solid electrolytic capacitor. 4A and 4B are diagrams illustrating a configuration of a conventional solid electrolytic capacitor, in which FIG. 4A is a schematic cross-sectional view of a capacitor element, FIG. 4B is a front view of a multilayer body of capacitor elements, and FIG. FIG. 4D is a schematic cross-sectional view of the solid electrolytic capacitor, and FIG. 4D is a cross-sectional view of the capacitor element taken along the line AA.

  Embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
BRIEF DESCRIPTION OF THE DRAWINGS It is a figure explaining the structure of Embodiment 1 of the solid electrolytic capacitor of this invention, Fig.1 (a) is sectional drawing of a capacitor | condenser element, FIG.1 (b) is a top view of a capacitor | condenser element, FIG.1 (c) ) Is a front view of a laminate of solid electrolytic capacitors, and FIG. 1D is a cross-sectional view of the solid electrolytic capacitors. In FIG. 1B, the graphite layer 5 is hatched.

  As shown in FIG. 1A, the capacitor element 20 has the same structure as that of a conventional capacitor element except for the first conductive paste layer 6 which is a conductive paste layer, and has an insulating portion made of an insulating resin. 8 is divided into an anode portion 10 and a cathode portion 15.

  The anode part 10 is a metal body obtained by removing the porous layer 3 of the metal body 1 made of a valve action metal such as an aluminum foil having two main surface parts provided with the porous layer 3 and side parts in contact with these main surface parts. It consists of a core 2 and a spacer 7 made of 42 alloy or the like. The metal core 2 and the spacer 7 are electrically connected by welding or the like.

  The cathode portion 15 is formed by providing a dielectric layer (not shown) on the surface of the metal body 1 and sequentially providing the solid electrolyte layer 4 and the graphite layer 5 on the surface of the dielectric layer. Here, the first conductive paste layer 6 of the present invention is formed so as to expose a part of the graphite layer 5.

  Furthermore, it demonstrates concretely with a top view. As shown in FIG. 1B, the first conductive paste layer 6 of the capacitor element 20 of the present invention has a graphite layer 5 on one side of the outer edge perpendicular to the longitudinal direction in the two main surface portions of the cathode portion 15. In the side surface portion that is in contact with the main surface portion, the graphite layer 5 is exposed at the portion in contact with the same outer edge portion. By forming the first conductive paste layer 6 in this manner, the conductive paste does not swell, the thickness of the capacitor element 20 is made uniform, and the solid electrolytic capacitor corresponding to the reduction in thickness is manufactured. It becomes possible to obtain a method.

  Subsequently, as illustrated in FIG. 1C, the stacked body 50 includes a plurality of capacitor elements 20 in which the anode portions 10 are electrically connected to each other by welding or the like, and the cathode portions 15 are the main parts of the cathode portion 15. It is formed by being electrically connected by a conductive adhesive applied to the surface portion. The second conductive paste layer 16 is formed on the surface of the first conductive paste layer 6 at the side surface of the stacked body 50. As a result, an increase in ESR can be suppressed, and a solid electrolytic capacitor having excellent electrical characteristics can be obtained.

  Note that the second conductive paste layer 16 in the side surface portion of the laminate 50 may be formed not only on the surface of the first conductive paste layer 6 but also on the surface of the exposed graphite layer 5. .

  In addition, according to the present invention, since a laminated body can be formed using a capacitor element with a uniform thickness, the distortion of the capacitor element due to resin molding when an exterior is provided is reduced, and the solid electrolytic capacitor that suppresses LC Is obtained.

  As shown in FIG. 1 (d), the laminate 50 is made of an insulating resin in which a cathode part and an anode part are respectively connected to electrode terminals 18 provided on a substrate 19 by a conductive adhesive 11 and molded. The exterior 25 is provided, and the solid electrolytic capacitor 70 of the present invention is completed.

  The valve action metal can be appropriately selected from niobium, titanium or alloys thereof in addition to aluminum.

  The solid electrolyte layer 4 is made of a conductive polymer such as manganese dioxide, polythiophene, polypyrrole, and derivatives thereof. In addition, since the manufacturing method to the solid electrolyte layer 4 can be implemented by a well-known method, it abbreviate | omits.

  Since the first conductive paste layer 6 and the second conductive paste layer 16 improve conductivity and adhesion, the conductive paste is made of at least one selected from silver, copper, or a mixture thereof, and a resin. A layer is preferred.

  The first conductive paste layer is formed using screen printing. The squeegee is moved in screen printing from the insulating part of the capacitor element toward the end of the cathode part. As the material of the screen plate, general polyester or the like may be used.

  At this time, in Embodiment 1, the dimension of the opening part of the screen plate is made shorter than the longitudinal dimension of the main surface part (dimension in the direction of moving the squeegee). When the first conductive paste layer is formed by shortening the dimension of the opening of the screen plate in the longitudinal direction, the outer edge portion of the graphite layer is blocked and the conductive paste is not applied, and the outer edge of the main surface portion The graphite layer comes to be exposed at the part.

  The width dimension of the opening of the screen plate (the dimension perpendicular to the direction in which the squeegee is moved) is larger than the width dimension of the main surface portion as in the prior art. Therefore, by forming the first conductive paste layer on the main surface portion, it is simultaneously formed on the side surface portion. Note that the first conductive paste layer is not formed on the side surface corresponding to the portion of the screen plate whose dimension is shortened in the longitudinal direction of the main surface.

  After the screen printing is completed, the first conductive paste layer of the capacitor element is heated and cured at a predetermined temperature and time to form a cathode part. As in the prior art, the anode part is formed by welding a metal core from which the porous layer of the metal body has been removed and a spacer made of 42 alloy or the like. Accordingly, it is possible to obtain a capacitor element having a uniform thickness by suppressing the swell of the conductive paste at the outer edge portion of the main surface portion in the cathode portion.

  Subsequently, a plurality of capacitor elements on which the first conductive paste layer is formed are prepared, the cathode portions are electrically connected to each other by using a conductive adhesive, and the anode portions are electrically connected to each other by welding or the like. Get.

  The second conductive paste layer is formed using a dispenser or the like. The conductive paste is applied to at least one surface of the first conductive paste layer and the graphite layer in the side surface portion of the laminate so as to electrically connect the capacitor elements to each other, and the second conductive paste layer is applied. Form. The thickness of the second conductive paste layer is not particularly limited as long as the ESR increase is suppressed and a necessary exterior can be obtained. In order to prevent an electrical short circuit of the capacitor element, it is necessary that the second conductive paste layer does not reach the anode part from the cathode part beyond the insulating part.

  Thereafter, in the same manner as in the prior art, the laminate is connected to the electrode terminal provided on the substrate 19 with a conductive adhesive or the like, and an exterior made of an insulating resin is provided by molding. The solid electrolytic capacitor of Embodiment 1 of the invention is obtained.

(Embodiment 2)
2A and 2B are diagrams for explaining the configuration of a second embodiment of the solid electrolytic capacitor of the present invention. FIG. 2A is a plan view of the capacitor element, and FIG. 2B is a laminate of the solid electrolytic capacitor. FIG.

  As shown in FIG. 2A, the first conductive paste layer 6 of the capacitor element 20 has two corner portions in contact with one side of the outer edge portion orthogonal to the longitudinal direction in the two main surface portions of the cathode portion 15. The graphite layer 5 is exposed, and also on the side part in contact with the main surface part, the graphite layer is formed so as to be exposed at the part in contact with the same outer edge part. Others are the same as in the first embodiment. In FIG. 2A, the graphite layer 5 is hatched.

  In the second embodiment, the screen printing for forming the first conductive paste layer 6 is performed using a screen plate provided with openings so as to cover two corners in contact with one side of the outer edge perpendicular to the longitudinal direction. To do. By forming the first conductive paste layer 6 excluding the corners where the swell is significant, the conductive paste in the outer edge portion of the main surface portion is reduced without reducing the formation region of the first conductive paste layer 6 as much as possible. Can be suppressed.

  As shown in FIG. 2B, in the multilayer body 50, in the plurality of capacitor elements 20, the anode portions 10 are electrically connected to each other by welding or the like, as in the first embodiment. Are electrically connected by a conductive adhesive applied to the main surface portion of the cathode portion 15. The second conductive paste layer 16 is formed on the surface of the first conductive paste layer 6 at the side surface of the stacked body 50. Accordingly, it is possible to provide a solid electrolytic capacitor that can suppress an increase in ESR and has excellent electrical characteristics.

  Thereafter, the cathode part and the anode part are connected to an electrode terminal provided on the substrate with a conductive adhesive or the like, and an exterior is provided. In this way, the thickness of the capacitor element is made uniform, so that a solid electrolytic capacitor and a method for manufacturing the same can be obtained.

  Further, similarly to the first embodiment, since a laminated body can be formed using a capacitor element having a uniform thickness, the distortion of the capacitor element due to resin molding for providing an exterior is reduced, and the solid is suppressed with LC. An electrolytic capacitor can be provided.

(Embodiment 3)
3A and 3B are diagrams for explaining the configuration of a solid electrolytic capacitor according to a third embodiment of the present invention. FIG. 3A is a plan view of the capacitor element, and FIG. 3B is a laminate of the solid electrolytic capacitor. FIG. In FIG. 3A, the graphite layer 5 is hatched.

  In the solid electrolytic capacitor according to Embodiment 3 of the present invention, as shown in FIG. 3A, the first conductive paste layer 6 formed on the capacitor element 20 is formed on the main surface portion of the cathode portion. The third embodiment is the same as the first embodiment except that it is formed so as to be exposed on three sides of the outer edge portion excluding one side in contact with the insulating portion.

  In the third embodiment, screen printing is performed using a screen plate provided with openings so as to cover three sides of the outer edge portion except one side in contact with the insulating portion in the main surface portion. Thereby, the swelling of the electrically conductive paste in the outer edge part of a main surface part can further be suppressed. Further, the first conductive paste layer on the side surface portion is formed because the opening portion of the screen plate is made smaller than the main surface portion so as to cover three sides of the outer edge portion excluding one side in contact with the insulating portion in the main surface portion. First, the graphite layer is exposed as compared with the first and second embodiments.

  FIG. 3B shows a state in which the second conductive paste layer 16 is formed on the side surface of the capacitor element 20 after the stacked body 50 is configured as in the first embodiment. As described above, since the formation region of the first conductive paste layer 6 in the main surface portion is further reduced, the graphite layer 5 is exposed as compared with the first and second embodiments. In addition, by increasing the coating area of the second conductive paste layer 16, the increase in ESR can be suppressed to the same extent as in the prior art.

  In the first conductive paste layer, the shape and area where the graphite layer is exposed are not limited to the above-described embodiment as long as it is possible to obtain a capacitor element that can achieve uniform thickness.

  Further, the present invention has been described by taking a two-terminal type solid electrolytic capacitor as an example in the embodiment, but can also be applied to a three-terminal type solid electrolytic capacitor.

  Examples of the present invention will be described below.

Example 1
In Example 1, a solid electrolytic capacitor having the configuration shown in FIG. 1 was produced. An etching layer is formed by roughening an aluminum foil which is a valve action metal having a thickness of 180 μm, and a dielectric layer made of an oxide film is formed on the surface of the etching layer at an applied voltage of 50 V using an adipine dihydrogen ammonium aqueous solution. Then, a chemical conversion foil was obtained. This chemical conversion foil was punched into a rectangular shape having a length of 6.45 mm and a width of 3.50 mm, and a resist layer was formed using an insulating resin made of an epoxy resin, and was divided into portions to be an anode portion and a cathode portion. The length of the portion to be the cathode portion was 4.75 mm.

  Subsequently, a solid electrolyte layer made of poly (3,4-ethylenedioxythiophene) was formed on the portion to be the cathode portion using a chemical polymerization method. Further, a graphite layer was formed on the surface of the solid electrolyte layer.

  Subsequently, the capacitor element on which the graphite layer was formed was disposed on a screen printing stage so that a silver paste could be applied to the main surface portion of the cathode portion. The prepared screen plate was placed on the cathode part, and a silver paste was placed on the screen plate. While pressing the squeegee against the screen plate, the squeegee was moved from the insulating part of the capacitor element toward the end of the main surface part in the cathode part, and the silver paste was applied. Thus, a first conductive paste layer having a width of 0.2 mm from the outer edge portion of the main surface portion toward the insulating portion and exposing the graphite layer was formed. This operation was performed on two main surface portions. Thereafter, the silver paste was heated and cured to form a cathode part. The anode part was formed by welding a metal core from which the porous layer of the metal body was removed and a spacer made of 42 alloy. The capacitor element of this example was obtained as described above.

  In addition, the width dimension of the screen plate was made larger than the width dimension of chemical conversion foil, and the 1st electroconductive paste layer was formed also in the side part except the part corresponding to the exposed part of a graphite layer. The material of the screen plate was polyester.

  Subsequently, four capacitor elements were laminated to obtain a laminated body. The cathode portions were electrically connected using a conductive adhesive or the like, and the anode portions were electrically connected by laser welding.

  Next, a silver paste was applied using a dispenser so as to cover about 50% of the two side surfaces in the longitudinal direction of the laminate, and heat-cured to form a second conductive paste layer.

  Thereafter, the anode part and cathode part of the laminate are electrically connected to the anode terminal and cathode terminal provided on the substrate, respectively, and an exterior made of an epoxy resin containing a glass filler is provided to complete the solid electrolytic capacitor of the present invention. It was. The number of solid electrolytic capacitors produced was 30.

(Example 2)
In Example 2, a solid electrolytic capacitor having the configuration shown in FIG. 2 was produced.

  The first conductive paste layer has a size of an isosceles triangle having one side of 0.4 mm at two corners in contact with one side of the outer edge perpendicular to the longitudinal direction in the two main surface portions of the cathode portion 15. To expose the graphite layer. In addition, the used members, manufacturing conditions, and the like were the same as in Example 1.

(Example 3)
In Example 3, a solid electrolytic capacitor having the configuration shown in FIG. 3 was produced.

  The first conductive paste layer was formed so as to expose the graphite layer with a width of 0.2 mm on three sides of the outer edge portion excluding one side in contact with the insulating portion in the main surface portion. Furthermore, the silver paste was apply | coated so that about 90% of the two side parts of the longitudinal direction of a laminated body might be covered using dispenser. Thereafter, heat curing was performed to form a second conductive paste layer. In addition, the used members, manufacturing conditions, and the like were the same as in Example 1.

(Comparative example)
The comparative example produced the solid electrolytic capacitor of the structure shown in FIG. Example 1 was performed except that the first conductive paste layer was formed so as to cover the entire surface of the cathode part.

  Table 1 shows the evaluation results of the solid electrolytic capacitors in Examples and Comparative Examples of the present invention. As evaluation items, in the laminate, a difference in thickness dimension and an ESR value at 100 KHz were measured. For a solid electrolytic capacitor, LC was measured. Regarding the difference in thickness dimension, the difference between the maximum value and the minimum value of the thickness of the solid electrolytic capacitor laminate of each level is described. ESR and LC are average values.

  As shown in Table 1, in Examples 1 to 3 of the present invention, the difference in thickness dimension is smaller than that in Comparative Example 1.

  Further, in Examples 1 to 3 of the present invention, ESR is reduced or suppressed to a substantially equivalent value as compared with Comparative Example 1. In LC, Examples 1 to 3 of the present invention are smaller than those of Comparative Example 1.

  As mentioned above, although the Example of this invention was described, this invention is not limited to these Examples, Even if there is a design change of the range which does not deviate from the summary of this invention, it is included in this invention. That is, various changes and modifications that can be naturally made by those skilled in the art are also included in the present invention.

1, 120 Metal body 2, 127 Metal body core 3, 126 Porous layer 4, 121 Solid electrolyte layer 5, 122 Graphite layer 6 First conductive paste layer 7, 124 Spacer 8, 125 Insulating part 10, 130 Anode part 11, 129 Conductive adhesive 15, 140 Cathode portion 16 Second conductive paste layer 18, 131 Electrode terminal 19, 145 Substrate 20, 100 Capacitor element 25, 150 Exterior 50, 210 Laminate 70, 220 Solid electrolytic capacitor 123 Conductive paste layer 128 Side silver paste layer

Claims (6)

The anode part is divided into an anode part and a cathode part by an insulating part, and the cathode part is flat and has a porous layer on the surface of a valve metal having two main surface parts and a side part in contact with the main surface part, and the porous part A dielectric layer, a solid electrolyte layer, a graphite layer, and a conductive paste layer are sequentially provided on the surface of the layer, and the anode portion has a capacitor element made of the valve metal derived from the insulating portion,
The capacitor element is a solid electrolytic capacitor having a plurality of stacked capacitor elements, an anode part and a cathode part being electrically connected to electrode terminals provided on a substrate and having an exterior covering the entire surface with an insulating material. And
The conductive paste layer includes a first conductive paste layer and a second conductive paste layer, and the first conductive paste layer has at least a part of an outer edge portion of the graphite layer in the main surface portion. The second conductive paste layer is exposed and at least a part of the graphite layer in the side surface portion is exposed, and the second conductive paste layer is formed of the graphite layer and the first conductive paste layer in the side surface portion. A solid electrolytic capacitor formed on at least one of the surfaces.   2. The solid electrolytic capacitor according to claim 1, wherein the first conductive paste layer is formed so as to expose corner portions of the graphite layer in the main surface portion which is an end portion of the capacitor element. .   2. The first conductive paste layer and the second conductive paste layer are formed of a conductive paste made of resin and at least one selected from silver, copper, or a mixture thereof. Or the solid electrolytic capacitor of 2. The anode part is divided into an anode part and a cathode part by an insulating part, and the cathode part is flat and includes a porous layer on the surface of a valve metal having two main surface parts and a side part in contact with the main surface part, and the porous A dielectric layer, a solid electrolyte layer, a graphite layer, and a conductive paste layer are sequentially provided on the surface of the layer, and the anode part is formed by laminating a plurality of capacitor elements made of the valve metal derived from the insulating part. A method of manufacturing a solid electrolytic capacitor having a process,
The conductive paste layer includes a first conductive paste layer and a second conductive paste layer, and the first conductive paste layer has at least a part of an outer edge portion of the graphite layer in the main surface portion. A step of forming by screen printing so as to expose at least a part of the graphite layer on the side surface, and the second conductive paste layer on the side surface and the graphite layer on the side surface Forming on at least one surface of the first conductive paste layer;
Electrically connecting the anode part and the cathode part to electrode terminals provided on a substrate, and providing an exterior covering the entire surface with an insulating material;
The manufacturing method of the solid electrolytic capacitor characterized by including this.   The first conductive paste layer is applied by screen printing from the direction of the insulating portion to the end portion of the cathode portion, and the corner portion of the graphite layer in the main surface portion that becomes the end portion of the capacitor element. The method of manufacturing a solid electrolytic capacitor according to claim 4, further comprising a step of forming the capacitor so as to expose the capacitor.   The conductive paste made of a resin and at least one selected from silver, copper, or a mixture thereof is used for forming the first conductive paste layer and the second conductive paste layer. 6. A method for producing a solid electrolytic capacitor according to 4 or 5.

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