JP4609042B2 - Solid electrolytic capacitor and method for producing solid electrolytic capacitor - Google Patents

Description

  The present invention relates to a solid electrolytic capacitor and a method for manufacturing the solid electrolytic capacitor, and more particularly to a solid electrolytic capacitor in which a plurality of capacitor elements are stacked and placed on a substrate, and a method for manufacturing the solid electrolytic capacitor.

As a solid electrolytic capacitor, a configuration in which a capacitor element is placed on a substrate to form one solid electrolytic capacitor has been conventionally known. For example, Japanese Unexamined Patent Application Publication No. 2004-104048 (see Patent Document 1) describes a solid electrolytic capacitor having this configuration. The solid electrolytic capacitor is configured by placing one or two capacitor elements constituting the solid electrolytic capacitor on a substrate, and conductive patterns connected to the anode part and the cathode part of the placed capacitor element, respectively. Is connected through a through hole to a conductive pattern provided on the side opposite to the side on which the capacitor element is placed.
Japanese Patent Laid-Open No. 2004-104048

  In order to ensure a high capacitance, it is conceivable that a plurality of substantially plate-like capacitor elements are stacked and electrically connected in parallel to form a solid electrolytic capacitor element. In this case, the capacitor element may have a structure in which a cathode portion is formed in a layered manner on a predetermined region of the surface of a plate-like anode portion made of a valve metal having an oxide film layer formed on the surface.

  More specifically, an insulating oxide film layer is formed on the entire surface of the valve action metal, and the cathode portion is composed of a solid electrolyte layer, a graphite paste layer, and a silver paste layer in this order on the oxide film layer. Is laminated. A plurality of capacitor elements having such a configuration are stacked and placed on a substrate. A first conductive pattern and a second conductive pattern are provided on the substrate, and the substrate is disposed so as to face the capacitor element of the first layer in a positional relationship parallel to the plurality of capacitor elements, and the stacked capacitor elements The anode part of the capacitor element of the first layer is electrically connected to the first conductive pattern, and the cathode part is electrically connected to the second conductive pattern.

  A first conductive pattern and a second conductive pattern are provided on the back surface of the substrate on which the stacked capacitor elements are placed, as with the surface facing the first layer of the stacked capacitor elements. The first conductive pattern and the second conductive pattern on the back surface are electrically connected to the first conductive pattern and the second conductive pattern on the surface through through holes formed in the substrate, respectively. The first conductive pattern and the second conductive pattern on the back surface are so-called user terminals for mounting the solid electrolytic capacitor in an electronic circuit or the like.

  Since the silver paste layer constituting the cathode portion has conductivity, the connection between the cathode portions of the plurality of capacitor elements and the second conductive pattern is performed by connecting a conductive adhesive between the cathode portions of the plurality of capacitor elements, Further, it is conceivable to perform the coating process between the cathode part of the capacitor element of the first layer and the second conductive pattern of the substrate.

  Since the insulating oxide film layer is formed on the entire surface of the anode part as described above, it cannot be connected using a conductive adhesive as in the case of the cathode part. Therefore, the connection of the anode portions of the plurality of capacitor elements to the first conductive pattern is performed by irradiating the laser from the top layer to the first layer in the stacking direction of the capacitor elements. It is conceivable that they are electrically connected to each other by being melted by a laser up to one conductive pattern.

  When performing laser irradiation, in order not to damage the user terminal of the substrate, that is, the first conductive pattern on the back surface of the substrate, the first anode on the surface of the substrate is penetrated by a plurality of anode portions through the laser. It is necessary to irradiate the conductive pattern and not to penetrate the substrate. This is because if the user terminal is damaged by penetrating the substrate, the reliability of the solid electrolytic capacitor is lowered, and the yield when manufacturing the solid electrolytic capacitor is deteriorated. In addition, moisture may enter from the damaged user terminal portion, leading to a short circuit.

  However, even if the laser irradiation output is adjusted to prevent damage to the user terminal, this adjustment is actually difficult because the capacitor elements are stacked in multiple layers. This causes the problem of damaging it. Further, if the output of laser irradiation is weakened so as not to penetrate the substrate, there arises a problem that welding of the plurality of capacitor elements to the first conductive pattern on the surface of the substrate becomes insufficient.

  Therefore, the present invention prevents the laser irradiation from penetrating the substrate when the laser is irradiated from the uppermost layer of the plurality of capacitor elements toward the first layer in the stacking direction of the capacitor elements. It aims at providing the manufacturing method of a solid electrolytic capacitor, and the solid electrolytic capacitor manufactured by the said manufacturing method.

  The present invention is a solid electrolytic capacitor including a substrate and a capacitor element. The substrate is provided with a first conductive pattern and a second conductive pattern on the front surface and the back surface, respectively, and the first conductive pattern and the second conductive pattern on the front surface are the first conductive pattern on the back surface, respectively. The conductive pattern is electrically connected to the second conductive pattern through a through hole. The capacitor element is composed of an anode portion formed of a valve metal having an oxide film layer formed on the surface, and a cathode portion formed in a layer shape having a solid electrolyte layer in a predetermined region on the surface of the anode portion. . The capacitor element is placed on the surface of the substrate, and the anode portion and the cathode portion are electrically connected to the first conductive pattern and the second conductive pattern of the substrate, respectively. The capacitor elements are formed in a plurality of substantially plate shapes, and the plurality of capacitor elements are stacked so that ends of the anode portions are adjacent to each other and the cathode portions are stacked adjacent to each other. The end portion of the anode portion and the cathode portion are aligned with the first conductive pattern and the second conductive pattern of the substrate, respectively. The plurality of capacitor elements include at least two types of capacitor elements for stacking fixing and capacitor elements for fixing the substrate. The ends of the anode portions of all the capacitor elements for fixing the layers and the ends of the anode portions of the capacitor elements for fixing the substrate have first connection portions that are welded to each other and are electrically connected to each other. . In addition, the end of the anode portion of the capacitor element for fixing the substrate is on the surface of the substrate at a position that does not overlap with the end portion of the anode portion of the capacitor element for fixing the multilayer in the stacking direction of the plurality of capacitor elements. A second connection portion that is welded to and electrically connected to the first conductive pattern.

  The end of the anode part of all the capacitor elements for fixing the layers and the end of the anode part of the capacitor elements for fixing the substrate have a first connection part welded to each other and electrically connected to each other, and fixed to the substrate. The end of the anode part of the capacitor element for welding is welded to the first conductive pattern on the surface of the substrate at a position where it does not overlap with the end of the anode part of the capacitor element for fixing in the stacking direction of the plurality of capacitor elements. Therefore, the capacitor element fixed to the substrate by the second connection portion can be only the capacitor element for fixing the substrate, and all the capacitor elements can be stacked in the stacking direction. It is possible to make the thickness relatively thinner than the total thickness when the capacitor elements are stacked. For this reason, when welding is performed to form the second connection portion, it becomes easy to adjust the irradiation output of welding, and by lowering the irradiation output of welding such as a laser, the substrate penetrates the substrate. It is possible to prevent the first conductive pattern on the back surface of the substrate from being damaged. For this reason, the reliability of a product and a yield can be improved.

  Also, a first conductive pattern and a second conductive pattern are provided on the front surface and the back surface, respectively, and the first conductive pattern and the second conductive pattern on the front surface are the first conductive pattern and the second conductive pattern on the back surface, respectively. The anode part and cathode part of a plurality of capacitor elements respectively laminated on the first conductive pattern and the second conductive pattern on the surface of the substrate electrically connected to the pattern through the through hole are electrically connected. Therefore, the first conductive pattern and the second conductive pattern on the back surface can be used as user electrodes. For this reason, compared with the case where a lead frame is used as a user terminal, the distance between the plurality of stacked capacitor elements and the user electrode can be extremely shortened, and ESR (equivalent series resistance) can be reduced.

  In addition, a through hole that connects the first conductive pattern on the front surface and the first conductive pattern on the back surface and a through hole that connects the second conductive pattern on the front surface and the second conductive pattern on the back surface are arranged close to each other in parallel. The anode portions of the stacked capacitor elements are electrically connected to the first conductive pattern, and the cathode portions of the stacked capacitor elements are electrically connected to the second conductive pattern. Because they are connected, the magnetic fluxes generated by the currents flowing through each through hole cancel each other, reducing ESL (equivalent series inductance) generated in the solid electrolytic capacitor compared to the case where a lead frame is used as a user terminal. Can do.

  Here, it is preferable that a low-melting-point metal material that melts by heat required for forming the second connection portion is interposed between the substrate and the capacitor element for fixing the substrate. With this configuration, instead of welding with a strong irradiation power laser or the like, the low melting point metal melted by heating the end of the anode portion of the capacitor element for fixing the substrate with a weak irradiation power laser or the like, The first conductive pattern and the capacitor element for fixing the substrate can be electrically connected.

  Moreover, this invention is a manufacturing method of the solid electrolytic capacitor which has a capacitor | condenser element manufacturing process and a board | substrate fixing process. The capacitor element manufacturing step includes a step of forming a cathode portion having a solid electrolyte layer in a predetermined region on the surface of an anode portion made of a valve metal having an oxide film layer formed on the surface. In the substrate fixing step, the capacitor element manufactured by the capacitor element step is placed and fixed on the substrate having the first conductive pattern and the second conductive pattern. The capacitor element manufacturing process includes a multilayer fixing capacitor element manufacturing process for manufacturing a substantially plate-shaped multilayer fixing capacitor element, and a substrate in which the shape of the end of the anode part is different from the multilayer fixing capacitor element. A plurality of capacitor elements are manufactured including a capacitor element manufacturing process for fixing a substrate for manufacturing a capacitor element for fixing. The substrate fixing step includes stacking the plurality of capacitor elements so that the end portions of the anode portion are adjacent to each other, and stacking the plurality of capacitor elements so that the cathode portions are adjacent to each other. A lamination step of aligning and arranging the end of the anode portion and the cathode portion on the conductive pattern, the second conductive pattern, and a connection step of electrically connecting the plurality of laminated capacitor elements to each other in parallel; The connection step includes a first conduction step of providing a first connection portion to electrically conduct by welding the first overlapping portion where all the anode portion end portions overlap in the stacking direction of the plurality of capacitor elements. In the stacking direction of the plurality of capacitor elements, the second overlapping of the capacitor element for fixing the substrate that does not overlap with the end portion of the anode portion of the capacitor element for fixing the multilayer and overlaps the first conductive pattern of the substrate A second conduction step of providing a second connection portion and electrically conducting the portion by welding the portion to the first conductive pattern of the substrate.

  The connection step includes a first conduction step of providing a first connection portion and electrically conducting by welding the first overlapping portions where all anode end portions overlap in the stacking direction of the plurality of capacitor elements, The second overlapping portion of the capacitor element for fixing the substrate that overlaps the first conductive pattern of the substrate without overlapping the end portion of the anode portion of the capacitor element for fixing the stack in the stacking direction of the capacitor elements And a second conduction step of providing a second connection portion and electrically conducting by welding to the conductive pattern. For this reason, the capacitor element fixed to the substrate by the second connection portion in the second conduction step can be only the capacitor element for fixing the substrate, and all the capacitor elements are stacked in the stacking direction of the plurality of capacitor elements. It can be made relatively thinner than the overall thickness of the case. As a result, when welding is performed to form the second connection portion, it becomes easy to adjust the irradiation output of welding, and welding such as a laser for mounting and fixing a plurality of capacitor elements on the substrate is facilitated. By reducing the irradiation output, it is possible to prevent the first conductive pattern on the back surface of the substrate from being damaged by penetrating the substrate. For this reason, the reliability of a product and a yield can be improved.

  Here, in the second conduction step, a low-melting-point metal material that melts by heat required to electrically connect the capacitor element for fixing the substrate to the first conductive pattern of the substrate, It is preferable to perform the step of interposing between the capacitor element for fixing the substrate. By performing this process, instead of welding with a laser with a strong irradiation power, etc., by a low melting point metal melted by heating the end of the anode part of the capacitor element for fixing the substrate with a laser with a low irradiation power, etc. The first conductive pattern on the substrate and the capacitor element for fixing the substrate can be electrically connected.

  As described above, the solid electrolytic capacitor prevents the laser irradiation from penetrating the substrate when the laser is irradiated from the uppermost layer of the plurality of capacitor elements toward the first layer in the stacking direction of the capacitor elements. And a solid electrolytic capacitor produced by the production method.

  A solid electrolytic capacitor and a method of manufacturing the solid electrolytic capacitor according to the first embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the solid electrolytic capacitor 1 includes four laminated capacitor elements 10 to 40, a printed circuit board 50, and a mold part (not shown) that molds so as to cover the four capacitor elements 10 to 40. It has.

  Each of the four capacitor elements 10 to 40 has substantially the same shape and substantially the same configuration, and includes anode parts 11 to 41 and cathode parts 12 to 42 as shown in FIG. The configuration of the four capacitor elements 10 to 40 is such that the shape of the left end portion 11B shown in FIG. 1 of the anode portion 11 of the capacitor element 10 is the same as that of the anode portions 21 to 41 of the other capacitor elements 20 to 40. 2 are the same except that they are different from the left end portions 21B to 41B shown in FIG. 2, and in the following description that will be described with reference to FIG. The description of the elements 20 to 40 is omitted. The parts having different shapes will be described later.

The anode part 11 has a substantially rectangular plate shape, and the long side is oriented in the left-right direction shown in FIGS. 1 and 2. The anode portion 11 is made of aluminum which is a valve metal, and as shown in FIG. 2, the surface thereof is roughened (enlarged) by etching to increase the surface area. It is porous. An insulating oxide film layer (dielectric layer) 11A is formed on the entire porous surface by chemical conversion treatment (anodic oxidation). The anode portion 11 has a length of about 10 mm in the longitudinal direction and a width of about 5 mm , and a thickness, that is, a vertical width shown in FIG. 2 of about 100 μm.

  A predetermined region on the surface of the anode part 11, that is, a position of approximately 2/3 of the length in the left-right direction of the anode part 11 from the right end part to the left end part 11B of the anode part 11 shown in FIG. A solid electrolyte layer 12A composed of a conductive polymer is formed in the entire region up to. The solid electrolyte layer 12A is provided by being laminated on the oxide film layer 11A, and the portion of the solid electrolyte layer 12A facing the oxide film layer 11A is in a porous formed on the surface of the anode part 11 by etching. It has entered. A graphite paste layer 12B and a silver paste layer 12C are laminated in this order on the solid electrolyte layer 12A, and the solid electrolyte layer 12A, the graphite paste layer 12B, and the silver paste layer 12C constitute the cathode portion 12. . The graphite paste layer 12B and the silver paste layer 12C are formed on the solid electrolyte layer 12A so as to cover the areas of the anode portion 11 and the oxide film layer (dielectric layer) 11A where the solid electrolyte layer 12A is formed. .

  A resist 13 made of an insulating epoxy resin or the like is provided at the boundary between the cathode portion 12 and the region of the anode portion 11 on the left side 11B shown in FIG. 2 where the cathode portion 12 is not provided. Is provided. The resist 13 is formed by capillary action on the surface of the anode portion 11 that is porous when the chemical conversion foil that becomes the anode portion 11 is immersed in the solution in order to form the solid electrolyte layer 12A on the anode portion 11. In order to prevent the solution from rising toward the left side in FIG. 2 from a predetermined region, and to secure the left end portion 11B shown in FIG. 2 of the anode portion 11 where the solid electrolyte layer 12A is not formed. Is provided.

  As shown in FIG. 1, the four capacitor elements 10 to 40 are stacked so that the cathode portions 12 to 42 are adjacent to each other. Since the cathode portions 12 to 42 are formed on the plate-like anode portions 11 to 41, the cathode portions 12 to 42 have upper surfaces 10A to 40A and lower surfaces 10B to 40B substantially perpendicular to the thickness direction of the anode portions 11 to 41. is doing. As shown in FIG. 1, the upper surface 10 </ b> A of the first capacitor element 10 and the lower surface 20 </ b> B of the second capacitor element 20 that form the first layer of the four capacitor elements 10 to 40 that are stacked are bonded together by the conductive adhesive 71. The upper surface 20A of the second capacitor element 20 and the lower surface 30B of the third capacitor element 30 are bonded by the conductive adhesive 71, and the upper surface 30A of the third capacitor element 30 and the lower surface 40B of the fourth capacitor element 40 are electrically conductive. Bonded by the adhesive 71. Accordingly, the cathode portions 12 to 42 of the four capacitor elements 10 to 40 are electrically connected, and the left ends of the anode portions 11 to 41 of the four capacitor elements 10 to 40 shown in FIG. Coupled with the portions 11B to 41B being electrically connected, the four capacitor elements 10 to 40 are electrically connected in parallel.

  The portions of the end portions 11B to 41B of the anode portions 11 to 41 where the cathode portions 12 to 42 of the four capacitor elements 10 to 40 are not provided are silver paste compared to the portion where the cathode portions 12 to 42 are provided. The layer 12C is thin because it is not formed. For this reason, as shown in FIG. 1, the left ends 11 </ b> B to 41 </ b> B shown in FIG. 1 of the anode parts 11 to 41 of the capacitor elements 10 to 40 are the first on the surface 50 </ b> A of the printed board 50 described later. The conductive patterns 51A are stacked so as to be adjacent to each other while being bent so as to be pressed against each other and in contact with each other.

  The left end portions 11B to 41B shown in FIG. 1 of the anode portions 11 to 41 of the capacitor elements 10 to 40 are bent from the first capacitor element 10 of the first layer toward the fourth capacitor element 40 which is the uppermost layer. The degree to which it is being increased. In FIG. 1, for convenience of explanation, the end portions 11 </ b> B to 41 </ b> B are shown with an emphasis on the degree of bending, but in reality, they are not so bent.

  The four capacitor elements 10 to 40 stacked are placed on a printed circuit board 50 having substantially the same shape as the anode portions 11 to 41. The printed board 50 is, for example, a printed board 50 made of epoxy resin. The four capacitor elements 10 to 40 are placed on the printed circuit board 50 so as to coincide with the printed circuit board 50 in shape. The printed circuit board 50 faces the cathode portion 12 of the first capacitor element 10 and the end portion 11B of the anode portion 11 among the four capacitor elements 10 to 40 stacked.

  First conductive patterns 51A and 51B and second conductive patterns 52A and 52B are provided on the front surface 50A and the back surface 50B of the printed circuit board 50, respectively. The first conductive pattern 51A and the second conductive pattern 52A on the front surface 50A are electrically connected to the first conductive pattern 51B and the second conductive pattern 52B on the back surface 50B through the through holes 50a and 50b, respectively. Yes. The through hole 50a and the through hole 50b are arranged close to each other and in parallel.

  The first conductive pattern 51A is disposed at a position facing the left end portion 11B of the anode portion 11 of the first capacitor element 10 shown in FIG. 1, and the second conductive pattern 52A is the first capacitor element. 10 are arranged at positions facing the cathode portions 12. The cathode portion 12 is electrically connected to the second conductive pattern 52A by a conductive adhesive 71.

  The first conductive pattern 51B and the second conductive pattern 52B on the back surface 50B of the printed board 50 are so-called user terminals mounted on an electronic circuit (not shown), respectively, and the first conductive pattern on the surface of the printed board 50 51A and the second conductive pattern 52A are made of the same metal material.

  Here, the shapes of the left end portions 11B to 41B shown in FIG. 1 of the anode portions 11 to 41 of the capacitor elements 10 to 40 will be described. As shown in FIG. 3, each of the left end portions 21B to 41B of the anode portions 21 to 41 of the capacitor elements 20 to 40 has two corner portions sandwiching one short side of a rectangular shape. , Each of which has a shape that is cut out and removed. Therefore, the longitudinal direction of the anode portions 21 to 41 having a substantially rectangular shape, that is, the left-right direction shown in FIG. The convex part 21C-41C which protrudes in the direction is provided.

  On the other hand, the left end portion 11B of the anode portion 11 of the capacitor element 10 shown in FIG. 1 has two corner portions sandwiching one short side of the rectangular shape of the anode portion 11, and the end portions 21B to 41B. Thus, the shape is not cut out and not removed, and the two corner portions remain as they are. Therefore, in the left end portions 11B to 41B shown in FIG. 1 of the anode portions 11 to 41 of the capacitor elements 10 to 40, in the portion of the convex portions 21C to 41C and the stacking direction of the plurality of capacitor elements 10 to 40 A portion 11D of the end portion 11B that overlaps the convex portions 21C to 41C forms a first overlapping portion that overlaps each other in the same direction. Further, the left and right end portions 11E and 11F in FIG. 3 of the end portion 11B that does not overlap the convex portions 21C to 41C in the stacking direction of the plurality of capacitor elements 10 to 40 are the same as the first conductive pattern 51A of the printed circuit board 50 in the same direction. A second superimposing unit for superimposing is formed. The capacitor element 10 corresponds to a capacitor element for fixing a substrate, and the capacitor elements 20 to 40 correspond to capacitor elements for fixing a layer.

  The first connecting portion 1A is provided in the first overlapping portion, that is, the portion of the convex portions 21C to 41C and the portion 11D of the end portion 11B that overlaps the convex portions 21C to 41C in the stacking direction of the capacitor elements 10 to 40. It has been. The first connecting portion 1A is welded to each other when the first overlapping portion receives the YAG laser irradiation in the direction in which the capacitor elements 10 to 40 are stacked and from the top to the bottom of FIG. The end portions 11B to 41B of 11 to 41 are electrically connected to each other.

  Further, as shown in FIG. 4, the second overlapping portion, that is, the left and right end portions 11 </ b> E to 11 </ b> F of the end portion 11 </ b> B that does not overlap with the convex portions 21 </ b> C to 41 </ b> C in the stacking direction of the plurality of capacitor elements 10 to 40. Connecting portions 1B and 1B are provided. The second connecting portion 1B receives the YAG laser irradiation from the top to the bottom of FIG. 1 in the stacking direction of the capacitor elements 10 to 40, so that the first capacitor element 10 The end portion 11B of the anode portion 11 and the first conductive pattern 51A on the surface 50A of the printed circuit board 50 are welded and are electrically connected to each other. The second connection portion 1B does not penetrate the printed circuit board 50 and remains at the position of the first conductive pattern 51A on the surface 50A of the printed circuit board 50. Therefore, the first conductive pattern 51B on the back surface 50B of the printed circuit board 50 is not damaged at all by the laser irradiation.

  The end portions 11B to 41B of the anode portions 11 to 41 of all the capacitor elements 10 to 40 have the first connection portion 1A, and the left and right end portions 11E and 11F of the end portion 11B of the anode portion 11 of the capacitor element 10 are all included. Has the second connection portion 1B, the capacitor element fixed to the printed circuit board 50 by the second connection portion 1B can be the first capacitor element 10 alone, and the capacitor elements 10 to 40 are stacked. It can be made relatively thinner than the total thickness when all the capacitor elements 10 to 40 are laminated in the direction.

  For this reason, when welding is performed in order to form the second connection portion 1B, it becomes easy to adjust the irradiation output of the welding, and by reducing the irradiation output of the welding such as a laser, the printed circuit board 50 can be reduced. It is possible to prevent the first conductive pattern 51 </ b> B on the back surface 50 </ b> B of the printed circuit board 50 from penetrating and being damaged. For this reason, the reliability of a product and a yield can be improved.

  The first conductive pattern 51A and the second conductive pattern 52A on the front surface 50A are electrically connected to the first conductive pattern 51B and the second conductive pattern 52B on the back surface 50B through the through holes 50a and 50b, respectively. The anode parts 11 to 41 and the cathode parts 12 to 42 of the laminated capacitor elements 10 to 40 are electrically connected to the first conductive pattern 51A and the second conductive pattern 52A on the surface 50A, respectively. Therefore, the first conductive pattern 51B and the second conductive pattern 52B on the back surface 50B can be used as user electrodes. For this reason, compared with the case where a lead frame is used as a user terminal, the distance between the plurality of stacked capacitor elements and the user electrode can be extremely shortened, and ESR (equivalent series resistance) can be reduced.

  Further, since the through hole 50a and the through hole 50b are arranged close to each other in parallel, the anode portions 11 to 41 of the stacked capacitor elements 10 to 40 are electrically connected to the first conductive pattern 51A. Since the cathode parts 12 to 42 of the laminated capacitor elements 10 to 40 are electrically connected to the second conductive pattern 52A, the magnetic fluxes generated by the current flowing through the through holes 50a to 50b cancel each other. In contrast, ESL (equivalent series inductance) generated in the solid electrolytic capacitor 1 can be reduced as compared with the case where a lead frame is used as the user terminal.

  In the method of manufacturing a solid electrolytic capacitor, first, a capacitor element manufacturing process is performed. In the actual capacitor element manufacturing process, a plurality of capacitor elements are manufactured at the same time. Here, for convenience of explanation, the process of manufacturing one capacitor element 10 is a single capacitor element manufacturing process. First, an aluminum film that is formed on the surface with an oxide film layer 11 </ b> A and serves as the anode portion 11, that is, a chemical conversion foil is punched out to form one end of the anode portion 11. At this time, as will be described later, the portion of the conversion foil on which the cathode layer is formed includes the other end portion of the conversion foil on which the cathode portions of other capacitor elements manufactured at the same time are formed, and an extra formation that does not become a product. It is in a state of being connected through the foil portion. In the cutting process performed immediately before the connection process described later, the excess chemical conversion foil portion is cut and removed.

  Next, using a screen printing method, a resist 13 is formed at a predetermined position of the anode portion 11 and a boundary between the cathode portion 12 and the anode portion 11. Next, when the chemical conversion foil is punched as described above, a portion where the oxide film layer 11A is not formed is formed in the punched cross section, but the oxide film layer 11A is formed again in this portion in order to generate the oxide film layer 11A. Perform re-formation.

  Next, a reaction solution for forming a solid electrolyte layer 12A on a predetermined region with the resist 13 as a boundary, that is, a portion of the chemical conversion foil corresponding to a portion on the right side of the resist 13 of the anode portion 11 shown in FIG. The solid electrolyte layer 12A, that is, the conductive polymer layer is formed by dipping in the substrate and performing chemical oxidative polymerization. Since the surface of the anode part 11 is made porous by etching, the silver paste layer 12C cannot be formed directly, so the solid electrolyte layer 12A is formed in preparation for forming the silver paste layer 12C.

  Next, for some reason, the oxide film layer 11A formed on the surface of the chemical conversion foil may be damaged. In order to correct this part, a repairing process is performed in which oxidation is performed again. Next, a graphite paste layer 12B and a silver paste layer 12C are stacked in this order on the conductive polymer layer. For forming the graphite paste layer 12B and the silver paste layer 12C, a dipping method, a screen printing method, a spray coating method, or the like is used. The above is the capacitor element manufacturing process. By performing this capacitor element manufacturing process four times, four capacitor elements are manufactured.

  Next, a lamination process is performed. In the laminating step, the four capacitor elements 10 to 40 are laminated so that the left end portions 11B to 41B shown in FIG. 1 of the anode portions 11 to 41 are adjacent to each other, and the cathode portions 12 to 42 are arranged to each other. Laminated and arranged so as to be adjacent to each other. A conductive adhesive 71 is applied between the cathode portions 12 to 42, and the cathode portions 12 to 42 are electrically connected to each other by the conductive adhesive 71. As the conductive adhesive 71, for example, a silver-epoxy adhesive is used.

  Next, the four capacitor elements 10 to 40 in the laminated state are cut from the portion of the excess chemical conversion foil that does not become a product to form the cathode parts 12 to 42, thereby forming the capacitor element 10 having a substantially rectangular shape. The shape is ˜40.

  Next, a connection process is performed. In the connection process, a first conductive process, a substrate placing process, and a second conductive process are performed. In the first conductive process, four capacitor elements 10 to 40 are electrically connected by electrically connecting the left end parts 11B to 41B shown in FIG. 1 of the anode parts 11 to 41 of the stacked capacitor elements 10 to 40. Are electrically connected in parallel with each other. Specifically, the YAG laser is irradiated from the stacking direction of the capacitor elements 10 to 40 to the first overlapping portion, that is, from the upper direction shown in FIG. 1 or FIG. 2, and as shown in FIG. One connecting portion 1A is provided. Thereby, the end portions 11B to 41B of the anode portions 11 to 41 of the capacitor elements 10 to 40 are electrically connected to each other.

  In the substrate mounting step, the stacked capacitor elements 10 to 40 are mounted on the surface 50 </ b> A of the printed circuit board 50 prepared separately from the four stacked capacitor elements 10 to 40. Specifically, the end 11B of the anode portion 11 of the first capacitor element 10 is opposed to the first conductive pattern 51A on the surface 50A of the printed circuit board 50, and the first conductive pattern 52A on the surface 50A is first in contact with the first conductive pattern 51A. The cathode portion 12 of the capacitor element 10 is opposed. Then, a conductive adhesive 71 is applied to the position of the cathode portion 12 facing the second conductive pattern 52 </ b> A, and the first capacitor 10 is bonded and fixed to the printed board 50.

  In the second conductive process, as shown in FIG. 4, the four stacked capacitor elements 10 to 40 are electrically connected on the printed board 50. Specifically, first, the convex portion 11C of the end portion 11B of the anode portion 11 of the capacitor element 10 is brought into contact with the first conductive pattern 51A, and the capacitor elements 10 to 40 are stacked with respect to the second overlapping portion. That is, the YAG laser is irradiated from the upper direction shown in FIG. 1 or 2 to provide the second connection portion 1B as shown in FIG. Thus, the convex portion 11C of the capacitor element 10 is electrically connected to the first conductive pattern 51A of the printed board 50.

  Thereafter, molding is performed to protect the solid electrolytic capacitor 1, cutting is performed, aging is performed to repair a damaged portion, and the entire method of manufacturing the solid electrolytic capacitor is performed through characteristic inspection and appearance inspection. The process ends.

  Since the connection process has a first conduction process for providing the first connection portion 1A and a second conduction process for providing the second connection portion 1B, welding is performed in two steps. In the second conduction step, the capacitor element fixed to the printed circuit board 50 by the second connecting portion 1B can be the capacitor element 10 alone, and all the capacitor elements 10-40 in the stacking direction of the capacitor elements 10-40 are provided. It is possible to make the thickness relatively thinner than the total thickness of the stacked layers.

  For this reason, when welding is performed to form the second connection portion 1B, it becomes easy to adjust the irradiation output of the welding, and the laser for mounting and fixing the capacitor elements 10 to 40 on the printed circuit board 50. It is possible to prevent the first conductive pattern 51 </ b> B on the back surface 50 </ b> B of the printed board 50 from being damaged by penetrating the printed board 50 by lowering the irradiation output of welding or the like. For this reason, the reliability of a product and a yield can be improved.

  Next, a solid electrolytic capacitor and a method for manufacturing the solid electrolytic capacitor according to the second embodiment of the present invention will be described with reference to FIGS. In the solid electrolytic capacitor 2 according to the second embodiment, a spacer 60 is provided between the printed board 50 and the end portion 11B ′ of the anode portion 11 ′ of the capacitor 10 ′, and the anode portion of the capacitor 10 ′. The shape of the end portion 11B 'of 11' is the same as the shape of the end portions 21B to 41B of the anode portions 21 to 41 of the other capacitors 20 to 40, and the solid electrolytic capacitor 1 according to the first embodiment. Is different.

  Since the shape of the end portion 11B 'of the anode portion 11' of the capacitor 10 'is the same as the shape of the end portions 21B to 41B of the anode portions 21 to 41 of the other capacitors 20 to 40, the end portion 11B' As shown in FIG. 6, a convex portion 11C ′ having the same shape as the convex portions 21C to 41C is provided.

  The spacer 60 has a substantially rectangular plate shape and is made of Ni. The spacer 60 is disposed between the left end portion 11B ′ shown in FIG. 5 of the anode portion 11 ′ of the first capacitor element 10 ′ and the first conductive pattern 51A of the printed circuit board 50. When viewed from the longitudinal direction of the anode portions 11 ′ to 41 ′ of 10 ′ to 40, that is, from the substantially left direction of FIG. 5, the central portion 61 is thick in the stacking direction of the capacitor elements 10 ′ to 40, as shown in FIG. 6. Has been.

  The central portion 61 is located between the convex portion 11C ′ of the left end portion 11B ′ shown in FIG. 5 of the anode portion 11 ′ of the first capacitor element 10 ′ and the first conductive pattern 51A of the printed circuit board 50. The central portion 61 and the convex portions 11C ′ to 41C form a first overlapping portion that overlaps with each other in the stacking direction of the capacitor elements 10 ′ to 40. The left and right end portions 62 and 63 of FIG. 6 of the spacer 60 do not overlap with the end portions 11B ′ to 41B of the anode portions 11 ′ to 41 of the capacitor elements 10 ′ to 40 in the stacking direction of the capacitor elements 10 ′ to 40. A second overlapping portion overlapping the first conductive pattern 51A of the printed circuit board 50 is formed.

  Since the thickness of the central portion 61 of the spacer 60 is large and a large space can be secured between the printed circuit board 50 and the end portion 11B ′ of the anode portion 11 ′, the end portion 41B of the anode portion 41 and the like are extremely large. It is possible to prevent bending. For this reason, it is possible to prevent cracks due to extreme bending at the end 41B of the anode part 41 and the like, and it is possible to prevent an increase in leakage current due to the crack and disconnection or poor connection of the end 41B of the anode part 41. Can be prevented.

  As shown in FIG. 6, the first connecting portion 2 </ b> A is provided in the first overlapping portion, that is, the end portions 11 </ b> B ′ to 41 </ b> B and the central portion 61. The first connecting portion 2A is welded to each other when the first overlapping portion receives the YAG laser irradiation in the stacking direction from the top to the bottom of FIG. The end portions 11B ′ to 41B and the central portion 61 of the spacer 60 are electrically connected to each other.

  In addition, the second overlapping portion, that is, the left and right end portions 62 and 63 in FIG. 6 of the spacer that does not overlap with the convex portions 11 ′ C to 41 C in the stacking direction of the plurality of capacitor elements 10 ′ to 40, 2B and 2B are provided. The second connecting portion 2B is a central portion of the spacer 60 when the second overlapping portion receives the YAG laser irradiation in the direction in which the capacitor elements 10 'to 40 are stacked and from the top to the bottom in FIG. 61 and the first conductive pattern 51A on the surface of the printed circuit board 50 are welded, and are electrically connected to each other. The second connection portion 2B does not penetrate the printed circuit board 50 and remains at the position of the first conductive pattern 51A on the surface of the printed circuit board 50. Therefore, the first conductive pattern 51B on the back surface of the printed circuit board 50 is not damaged at all by the laser irradiation.

  Since the end portions 11B 'to 41B of the anode portions 11' to 41 of all the capacitor elements 10 'to 40 and the spacer 60 have the first connection portion 2A, and the spacer 60 has the second connection portion 2B, The portion fixed to the printed circuit board 50 by the second connection portion 2B can be only the spacer 60, and when all the capacitor elements 10 'to 40 and the spacer 60 are stacked in the stacking direction of the capacitor elements 10' to 40 It can be made relatively thinner than the overall thickness of.

  For this reason, when welding is performed to form the second connection portion 2B, it becomes easy to adjust the irradiation output of the welding, and by reducing the irradiation output of the welding such as a laser, the printed circuit board is welded. It is possible to prevent the first conductive pattern 51 </ b> B on the back surface 50 </ b> B of the printed circuit board 50 from being damaged by penetrating 50. For this reason, the reliability of a product and a yield can be improved.

  In the method for manufacturing a solid electrolytic capacitor, not only the convex portions 21C to 41C but also the convex portion 11C ′ is provided. Further, in the stacking process, together with the four capacitor elements 10 ′ to 40, the central portion 61 of the spacer 60 overlaps with the convex portion 11 C ′ of the capacitor element 10 ′, and the left and right end portions of the spacer do not overlap with the convex portion 11 C ′. In addition, the spacer 60 is laminated on the capacitor elements 10 ′ to 40.

  In the first conductive step, the left end portions 11B ′ to 41B shown in FIG. 1 of the anode portions 11 ′ to 41 of the capacitor elements 10 ′ to 40 and the central portion 61 of the spacer 60 are electrically connected. Four capacitor elements 10 'to 40 are electrically connected in parallel to each other. Specifically, the YAG laser is irradiated from the stacking direction of the capacitor elements 10 ′ to 40, that is, from the upper direction shown in FIG. 1 or 2 to the first overlapping portion, as shown in FIG. A first connecting portion 2A is provided. Thus, the end portions 11B ′ to 41B of the anode portions 11 ′ to 41 of the capacitor elements 10 ′ to 40 and the central portion 61 of the spacer 60 are electrically connected to each other.

  In the substrate mounting step, the capacitor elements 10 ′ to 40 are stacked on the surface 50 A of the printed circuit board 50 prepared separately from the four stacked capacitor elements 10 ′ to 40. Place with. Specifically, the spacer 60 is made to face the first conductive pattern 51A on the surface 50A of the printed board 50, and the cathode portion 12 'of the first capacitor element 10' is made to face the second conductive pattern 52A on the surface 50A. Let Then, a conductive adhesive 71 is applied to the position of the cathode portion of the capacitor element 10 ′ facing the second conductive pattern 52 A, and the first capacitor 10 ′ is bonded and fixed to the printed board 50.

  In the second conductive process, as shown in FIG. 6, four stacked capacitor elements 10 ′ to 40 on the printed circuit board 50 are electrically connected together with the spacer 60. Specifically, first, the spacer 60 is brought into contact with the first conductive pattern 51A, and from the stacking direction of the capacitor elements 10 'to 40 with respect to the second overlapping portion, that is, as shown in FIG. YAG laser is irradiated from the direction to provide second connection portions 2B and 2B as shown in FIG. As a result, the spacer 60 is electrically connected to the first conductive pattern 51 </ b> A of the printed circuit board 50.

  In the connecting step, the first connecting portion 2A is welded to each other by welding the anode portions 11 'to 41 end portions 11B' to 41B and the first overlapping portion where the spacer 60 overlaps in the stacking direction of the capacitor elements 10 'to 40. The printed circuit board does not overlap with the first conduction step that is electrically conducted and the end portions 11B ′ to 41B of the anode portions 11 ′ to 41 of the capacitor elements 10 ′ to 40 in the stacking direction of the capacitor elements 10 ′ to 40 The second overlapping portion of the spacer 60 that overlaps the first conductive pattern 51A of 50 is welded to the first conductive pattern 51A of the printed circuit board 50 to provide the second connection portion 2B to be electrically conductive. Therefore, only the spacer 60 can be fixed to the printed circuit board 50 by the second connection portion 2B in the second conduction step. It can be relatively thinner than the total thickness of the case of stacking all the capacitor element 10'～40 and spacer 60 in the stacking direction of the capacitor element 10'～40.

  For this reason, when welding is performed to form the second connection portion 2B, it becomes easy to adjust the irradiation output of the welding, and the capacitor elements 10 'to 40 are placed and fixed on the printed board 50. By reducing the irradiation output of welding such as laser, it is possible to prevent the first conductive pattern 51B on the back surface 50B of the printed board 50 from being damaged by penetrating the printed board 50. For this reason, the reliability of a product and a yield can be improved.

  The solid electrolytic capacitor and the method for manufacturing the solid electrolytic capacitor according to the present invention are not limited to the above-described embodiments, and various modifications and improvements can be made within the scope described in the claims. For example, a low melting point metal may be interposed between the first capacitor element 10 and the printed board 50 or between the spacer 60 and the printed board 50. For example, Sn, solder, Zn or the like is used as the low melting point metal.

  With this configuration, the low melting point metal can be melted by heat generated by laser irradiation that is weaker than the laser irradiation output of the second conductive process in the present embodiment, and the first capacitor element 10 and the printed circuit board 50 can be melted by the low melting point metal. And a second connection part that electrically connects the spacer 60 and the printed circuit board 50 can be provided. Further, instead of interposing the low melting point metal between the spacer 60 and the printed board 50, the spacer itself may be made of a low melting point metal. With this configuration, the step of providing the low melting point metal on the spacer can be omitted.

  Moreover, even if the anode part of the first layer of the stacked capacitor elements does not have the second overlapping part, the anode part of the upper layer such as the second layer has the second overlapping part. Good. Further, there may be a plurality of capacitor elements including an anode part having a second overlapping part. Similarly, the spacer is not between the printed board 50 and the end portion 11B ′ of the anode portion 11 ′, but between the end portion 11B ′ of the anode portion 11 ′ and the end portion 21B of the anode portion 21 of the capacitor element 21, for example. It may be arranged.

  Although the spacer is provided in an integral configuration, it may not be integral. For example, a plate-shaped square member having a width substantially the same as the width of the rectangular member is stacked and mounted and fixed at a substantially central position of the plate-shaped rectangular member, and configured by a plurality of plate-shaped members. However, the central portion may be thickened. Moreover, although the center part was comprised thickly, it does not need to be thick. Therefore, the spacer may be formed of a simple flat member.

  Further, when the capacitor elements 10 ′ to 40 are stacked, the degree of bending so that the end portions 11 B ′ to 41 of the anode portions 11 ′ to 41 of the capacitor elements 10 ′ to 40 are in contact with each other. For the purpose of reduction, in order to secure a space from the first conductive pattern 51A of the printed circuit board 50 to the end portion 11B ′ of the anode portion 11 ′ of the first capacitor element 10 ′, the substrate 60 is replaced with the spacer 60. The conductive pattern on the surface may be thickened.

  Moreover, although the valve action metal which comprises the anode parts 11 and 11'-41 was comprised with aluminum, it is not limited to this. For example, tantalum or niobium may be used. Moreover, although the spacer 60 was comprised with Ni, it is not limited to this. For example, any conductive metal such as SUS, iron, aluminum, copper, phosphor bronze, Mo, Cr, or an alloy containing one or more of these may be used. For example, products manufactured by Hitachi Cable, Ltd. A so-called clad material obtained by metallographically joining dissimilar metals such as “Hitachi High Clad” may be used. Further, although four capacitor elements 10, 10 'to 40 are provided, the number is not limited to four.

  Further, although YAG laser spot welding is used as the laser, it is not limited to this, and for example, a second harmonic laser, an LD (semiconductor) laser, an excimer laser, or the like may be used. Further, welding is not limited to laser. Solder may be used, resistance welding may be performed, or reflow may be performed. In the case of soldering or reflow, the possibility of damaging the substrate can be extremely reduced.

  The first connection portions 1A, 2A and the second connection portions 1B, 2B are provided by irradiating laser from the stacking direction of the capacitor elements 10 to 40, respectively. However, the direction of laser irradiation is limited to this direction. I can't. For example, the direction perpendicular to the stacking direction may be used.

  The solid electrolytic capacitor and the method for manufacturing the solid electrolytic capacitor of the present invention are useful in the fields of a solid electrolytic capacitor configured by laminating a large number of capacitor elements and a method for manufacturing the solid electrolytic capacitor.

Sectional drawing which shows the solid electrolytic capacitor by the 1st Embodiment of this invention. Sectional drawing which shows the capacitor | condenser element which comprises the solid electrolytic capacitor by the 1st Embodiment of this invention. 1 is an exploded perspective view showing a solid electrolytic capacitor according to a first embodiment of the present invention. The principal part perspective view which shows the solid electrolytic capacitor by the 1st Embodiment of this invention. The principal part sectional drawing which shows the modification of the solid electrolytic capacitor by the 2nd Embodiment of this invention. The principal part perspective view which shows the solid electrolytic capacitor by the 2nd Embodiment of this invention.

Explanation of symbols

1, 2 Solid electrolytic capacitors 1A, 2A 1st connecting portion 1B, 2B 2nd connecting portion 10, 10 'to 40 Capacitor element 11, 11' to 41 Anode portion 11A Oxide film layer 11B, 11B 'to 41B End portion 11C, 11C'-41C Convex parts 12-42 Cathode part 12A Solid electrolyte layer 12B Graphite paste layer 12C Silver paste layer 50 Printed circuit board 51A, 51B First conductive pattern 52A, 52B Second conductive pattern 60 Spacer 61 Central portions 62, 63 Left and right edges

Claims (4)

A first conductive pattern and a second conductive pattern are provided on the front surface and the back surface, respectively, and the first conductive pattern on the front surface and the second conductive pattern are on the first conductive pattern on the back surface, A substrate electrically connected to the second conductive pattern through the through hole;
A capacitor element comprising: an anode portion formed of an oxide film layer on the surface and made of a valve metal; and a cathode portion having a solid electrolyte layer in a predetermined region on the surface of the anode portion and formed in layers. Prepared,
The capacitor element is a solid electrolytic capacitor that is placed on the surface of the substrate and in which the anode portion and the cathode portion are electrically connected to the first conductive pattern and the second conductive pattern of the substrate, respectively. Because
The capacitor elements are formed in a plurality of substantially plate shapes, and the plurality of capacitor elements are stacked so that ends of the anode portions are adjacent to each other and the cathode portions are stacked adjacent to each other. The end of the anode part and the cathode part are aligned with the first conductive pattern and the second conductive pattern of the substrate, respectively.
The plurality of capacitor elements have at least two types of capacitor elements for fixing the laminate and capacitor elements for fixing the substrate,
The end portions of the anode portions of all the capacitor elements for fixing the layers and the end portions of the anode portions of the capacitor elements for fixing the substrate have first connection portions that are welded to each other and are electrically connected to each other. And the end of the anode portion of the capacitor element for fixing the substrate is located on the surface of the substrate at a position that does not overlap the end of the anode portion of the capacitor element for fixing the multilayer in the stacking direction of the plurality of capacitor elements. A solid electrolytic capacitor comprising a second connecting portion welded to and electrically connected to the first conductive pattern.   2. The solid according to claim 1, wherein a low melting point metal material that melts by heat required for forming the second connection portion is interposed between the substrate and the capacitor element for fixing the substrate. Electrolytic capacitor. A capacitor element manufacturing step including a step of forming a cathode portion having a solid electrolyte layer in a predetermined region on the surface of an anode portion formed of an oxide film layer on the surface and made of a valve metal;
  A method of manufacturing a solid electrolytic capacitor comprising a substrate fixing step of mounting and fixing a capacitor element manufactured by the capacitor element step on a substrate having a first conductive pattern and a second conductive pattern,
  The capacitor element manufacturing process includes a multilayer fixing capacitor element manufacturing process for manufacturing a substantially plate-shaped multilayer fixing capacitor element, and a substrate in which the shape of the end of the anode part is different from the multilayer fixing capacitor element. A capacitor element manufacturing process for fixing a substrate for manufacturing a capacitor element for fixing, and manufacturing a plurality of capacitor elements,
  The substrate fixing step includes stacking the plurality of capacitor elements so that the end portions of the anode portion are adjacent to each other, and stacking the plurality of capacitor elements so that the cathode portions are adjacent to each other. A stacking step of aligning and arranging the end of the anode portion and the cathode portion on the conductive pattern, the second conductive pattern, and a connecting step of electrically connecting the stacked capacitor elements to each other in parallel; ,
  The connection step includes a first conduction step of providing a first connection portion to electrically conduct by welding the first overlapping portion where all the anode portion end portions overlap in the stacking direction of the plurality of capacitor elements. In the stacking direction of the plurality of capacitor elements, the second overlapping of the capacitor element for fixing the substrate that does not overlap with the end portion of the anode portion of the capacitor element for fixing the multilayer and overlaps the first conductive pattern of the substrate And a second conduction step of electrically connecting the first conductive pattern of the substrate with the first conductive pattern of the substrate to provide a second connection portion. In the second conduction step, a low melting point metal material that melts by heat required to electrically connect the capacitor element for fixing the substrate to the first conductive pattern of the substrate is fixed to the substrate and the substrate. The method for producing a solid electrolytic capacitor according to claim 3, wherein a step of interposing between the capacitor element and the capacitor element is performed.

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