JP2011009476A - Lower-surface electrode type solid electrolytic capacitor and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lower surface electrode type solid electrolytic capacitor and a method of manufacturing the same, capable of suppressing deterioration of leakage current characteristics, without an anode lead curving.SOLUTION: An anode lead support body 4 is melted and electrically jointed to an anode lead 2 lead from a capacitor element 1. A conductive via hole 17 for an anode of a mounted electrode 12 for an anode, which is provided on an insulating plate 13 of a printed wiring board 14, and whose bottom surface is a conduction surface 11, and the anode lead support body 4 are electrically jointed by a conductive member 8. Furthermore, a conduction via hole 16 for a cathode, which is provided on the insulating plate 13 of the printed wiring board 14, and whose bottom surface is a conduction surface 9 of a mounted electrode 10 for a cathode, and a cathode 19 of the capacitor element 1 are electrically joined by a conductive adhesive agent 5; and then, the capacitor element 1 is covered with an exterior resin 3 with insulation.

Description

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

  Conventionally, solid electrolytic capacitors using tantalum, niobium, etc. as valve action metals are small, have large capacitance, have excellent frequency characteristics, and are widely used in CPU (Central Processing Unit) decoupling circuits or power supply circuits. ing. With the development of portable electronic devices, in particular, bottom electrode type solid electrolytic capacitors have become widespread.

  As such a bottom electrode type solid electrolytic capacitor, for example, Patent Document 1 discloses an electronic component in which a capacitor element is connected to a printed wiring board on which an anode electrode and a cathode electrode are formed.

  In Patent Document 1, in a chip capacitor in which a capacitor element having a lead-out lead and an electrode substrate serving as an electrode of a capacitor are coated with an exterior resin, the electrode substrate is insulated with at least two through holes. A conductive plate covering the lower surface of the through-hole, and a plating layer in contact with the conductive plate, connecting the lead-out lead and the metal strip, and electrically connecting the metal strip and the electrode substrate A bottom electrode type solid electrolytic capacitor connected by layers is described.

JP 2002-8944 A

  As a conventional bottom electrode type solid electrolytic capacitor as shown in Patent Document 1, for example, there is a bottom electrode type solid electrolytic capacitor shown in FIG. FIG. 3 is a cross-sectional view illustrating a conventional bottom electrode type solid electrolytic capacitor.

  A conventional bottom electrode type solid electrolytic capacitor shown in FIG. 3 includes a capacitor element 41 from which an anode lead 42 is led out, an anode lead support 44 welded and electrically connected to the anode lead 42, and a rod-like or A block-shaped anode internal electrode 51 is embedded, and on one surface of the insulating plate 53, an anode mounting electrode 52 electrically connected to the conduction surface 502 of the anode internal electrode 51 is disposed. The conductive surface 501 of the anode internal electrode 51 that is electrically connected to the anode lead support 44 via the conductive adhesive 45 is disposed on the other surface, and the insulating plate 53 has a rod-like or block-like shape. The cathode internal electrode 49 is embedded, the cathode mounting electrode 50 electrically connected to the conductive surface 504 of the cathode internal electrode 49 is disposed on one surface of the insulating plate 53, and the other side of the insulating plate 53 is disposed. Conductive adhesive on the surface A printed wiring board 54 on which the conductive surface 503 of the cathode internal electrode 49 is disposed, which is electrically connected to the cathode portion 59 of the capacitor element 41 through 45, and an exterior resin 43 that covers the capacitor element 41 and has an insulating property. Have

  Further, the conventional bottom electrode type solid electrolytic capacitor shown in FIG. 3 includes an anode mounting electrode 52 electrically connected to the conductive surface 502 of the anode internal electrode 51 provided on the printed wiring board 54, and the printed wiring board 54. The cathode mounting electrode 50 electrically connected to the conduction surface 504 of the cathode internal electrode 49 provided on the same surface is provided on the same surface of the printed wiring board 54, and the anode mounting electrode 52 and the cathode mounting electrode 50 are provided. The surface of the bottom electrode type solid electrolytic capacitor becomes a mounting surface for other electronic components.

  In the conventional manufacturing method of the bottom electrode type solid electrolytic capacitor, the anode lead support 44 is welded and electrically joined to the anode lead 42 led out from the capacitor element 41, and the conductive surface of the anode internal electrode 51 is further connected. After applying the conductive adhesive 45 to 501, the end surface of the anode lead support 44 not connected to the anode lead 42 is mounted in contact with the applied conductive adhesive 45, and further, the cathode After the conductive adhesive 45 is applied to the conductive surface 503 of the internal electrode 49, the cathode element 59 is brought into contact with the applied conductive adhesive 45 to mount the capacitor element 41, and each conductive adhesive 45 is heated. After the capacitor element 41 is provided on the printed wiring board 54, the capacitor element 41 is covered with an insulating resin 43 having an insulating property to obtain a bottom electrode type solid electrolytic capacitor.

  The conventional bottom electrode type solid electrolytic capacitor has an error in the outer dimensions of components constituting the bottom electrode type solid electrolytic capacitor, such as anode lead, anode lead support, printed wiring board, capacitor element, etc. In addition, there is a processing error in the joining process of these components. Due to these errors, when the anode lead support is welded to the anode lead derived from the capacitor element, there may be a difference in height between the lower surface of the capacitor element installed on the printed wiring board and the lower surface of the anode lead support. When mounting the capacitor element with the anode lead support welded on the printed circuit board, especially when the lower surface of the anode lead support protrudes downward from the lower surface of the capacitor element, the lower surface of the anode lead support is printed. There is a problem that the anode lead is bent by being pressed against the electrode of the wiring board, and the leakage current characteristic of the bottom electrode type solid electrolytic capacitor is deteriorated.

  An object of the present invention is to solve the above-described problems, and to provide a bottom electrode type solid electrolytic capacitor capable of suppressing deterioration of leakage current characteristics without bending an anode lead and a method for manufacturing the same.

  According to the present invention, a capacitor element in which a cathode is provided on a porous body made of a valve action metal from which an anode lead is derived, and an anode lead support in which one end is welded and electrically joined to the anode lead. An anode internal electrode electrically joined to the anode lead support, and a cathode internal electrode electrically joined to the cathode portion on one surface, and the anode internal electrode Bonded anode mounting electrode, printed wiring board having cathode mounting electrode electrically bonded to the cathode internal electrode on the other surface, and insulating exterior resin containing the capacitor element In the bottom electrode type solid electrolytic capacitor having the above, at the position of the internal electrode for the anode, a cross-sectional shape is a concave hole, and a conductive via hole for the anode subjected to plating treatment is provided on the inner surface of the hole, A bottom electrode type, wherein a conductive member is provided in the anode conductive via hole, and the anode mounting electrode and the anode lead support are electrically joined to the anode conductive via hole and the anode lead support. A solid electrolytic capacitor is obtained.

  Further, according to the present invention, the anode lead is led out from both opposing side surfaces of the capacitor element, the anode lead support provided on both ends of the anode lead, the conductive via hole for the anode, and the conductive member. Thus, the above-described bottom electrode type solid electrolytic capacitor is obtained, which is electrically joined to each other.

  Further, according to the present invention, the cathode internal electrode has an opening having an area equal to or less than the area of the surface to be bonded to the printed wiring board at the position of the cathode, the hole having a concave cross section, and the hole A conductive via hole for the cathode subjected to the plating treatment is provided on the inner surface of the cathode, and a conductive adhesive is provided in the conductive via hole for the cathode, and the conductive via hole for the cathode and the cathode portion are electrically connected via the conductive adhesive. The above-described bottom electrode type solid electrolytic capacitor is obtained, which is characterized in that it is bonded to the base electrode.

  According to the present invention, there is obtained the above-described bottom electrode type solid electrolytic capacitor, wherein the conductive member is a solder having a melting point of 220 ° C. or higher.

  In addition, according to the present invention, the above-described bottom electrode type solid electrolytic capacitor is obtained, wherein the conductive member is a conductive adhesive.

  According to the invention, the anode mounting electrode and the cathode mounting electrode have copper as a base material, a nickel layer is provided on the surface of the base material, and a gold plating layer is further provided. The above-described bottom electrode type solid electrolytic capacitor is obtained.

  Further, according to the present invention, the anode mounting electrode and the cathode mounting electrode are used as bottom surfaces, and a hole having a concave cross section is provided in the printed wiring board, and then the inner surface of the hole is plated, A step of forming a conductive via hole, a step of providing the conductive member in the conductive via hole for anode, a step of providing the conductive adhesive in the conductive via hole for cathode, and the anode lead support not connected to the anode lead Inserting an end of a body into the anode conductive via hole, electrically connecting the anode lead support and the anode conductive via hole through the conductive member, and the conductive adhesive through the conductive adhesive. The method of manufacturing a bottom electrode type solid electrolytic capacitor as described above, comprising the step of electrically joining the cathode conductive via hole and the cathode portion.

  The present invention removes a predetermined region of the insulating plate from the surface of the insulating plate on the side where the copper layer is not provided, with respect to the printed wiring board provided with the copper layer on one side of the insulating plate. The conductive surface of the anode mounting electrode on the bonded side is exposed, the exposed conductive surface of the anode mounting electrode is the bottom surface, a hole having a concave cross section is formed, and plating is performed on the inner surface of the hole. An anode lead support to be welded to the derived anode lead and a conductive via hole for anode to be electrically joined are prepared, and the conductive surface of the cathode mounting electrode on the side to which the insulating plate is bonded is exposed to expose the cathode A conductive via hole for a cathode that is electrically connected to the cathode portion of the capacitor element can be manufactured by providing a hole having a concave cross-sectional shape with the conductive surface of the mounting electrode as a bottom surface and plating the inner surface of the hole.

  The conductive via hole for anode of the present invention has an opening larger than the area of the surface to be joined to the anode lead support, which is used when the capacitor element is installed on the printed wiring board. The end of the anode lead support that is not connected to the anode lead is inserted into the hole formed, and the conductive via hole for anode and the anode lead support can be electrically joined via the conductive member. It is possible to prevent an external force from being applied to the anode lead support without directly contacting the end portion of the support and the conductive surface of the electrode provided on the printed wiring board.

  Further, in the present invention, a copper layer is applied to the area of the printed wiring board on which the anode lead supporting body that is welded to both ends of the anode lead led out from both side surfaces of the capacitor element is used using the anode lead penetrating the capacitor element. A predetermined region of the insulating plate is removed from the surface of the insulating plate on the side not provided, the conductive surface of the anode mounting electrode bonded to the insulating plate is exposed, and the exposed conductive surface of the anode mounting electrode is exposed. Is used as a bottom surface, a hole having a concave cross-sectional shape is provided, plating is performed on the inner surface of the hole, and the anode lead is electrically connected to the welded anode lead support to produce two anode conductive via holes, The conductive surface of the cathode mounting electrode on the side bonded to the insulating plate is exposed, the exposed conductive surface of the cathode mounting electrode is the bottom surface, a hole having a concave cross section is formed, and the inner surface of the hole is plated , Cathode and electricity It can be produced cathode conductive via holes to be joined to.

  The two conductive via holes for anode of the present invention have openings larger than the area of the surface to be joined to the anode lead support used when the capacitor element is installed on the printed wiring board. The two anode leads and the end of the unconnected anode lead support are respectively inserted into the holes formed for the conductive via holes for electrical connection, and the two conductive via holes for anodes and the respective anode lead supports are electrically connected through the conductive member. At the time of bonding, the end of the anode lead support and the conductive surface of the electrode provided on the printed wiring board are not in direct contact with each other, and the two anode via holes are opposed to each other centering on the capacitor element. By disposing at the position, the cathode portion of the capacitor element serves as a fulcrum, and the insertion depth of the anode lead support inserted into the two conductive via holes for anode can be easily adjusted. It is possible to take the parallelism of the capacitors elements and the printed circuit board, it can be further prevented that the external force is applied to the anode lead support.

  Further, in the present invention, since the solder is used for the conductive member, the solder can be melted by heat at the time of soldering, and the end of the anode lead support can be immersed, so that the end of the anode lead support is distorted. Generation of external force can be prevented.

  Furthermore, since the melting point of general solder used in reflow soldering processing is less than 200 ° C., when soldering and mounting the bottom electrode type solid electrolytic capacitor according to the present invention to other electronic components or electronic devices In addition, by using a solder having a melting point of 220 ° C. or higher as the conductive member (hereinafter referred to as “high temperature solder”), the conductive member is not remelted by heat in reflow soldering or the like, and according to the present invention. Occurrence of poor conduction in the mounting operation of the bottom electrode type solid electrolytic capacitor can be suppressed.

  In the present invention, the end of the anode lead support is easily embedded in the conductive adhesive by using the conductive adhesive for the conductive member, which is generally in a paste or liquid form. It is possible to prevent the generation of an external force that distorts the end portion of the anode lead support.

  Further, in the present invention, the bonding area between the conductive adhesive and the cathode part can be made appropriate by setting the opening of the conductive via hole for the cathode to be equal to or smaller than the area of the surface of the capacitor element where the cathode part is bonded to the printed wiring board. Further, it is possible to suppress the occurrence of short-circuit failure due to adhesion due to the protruding conductive adhesive, and to secure the bonding strength between the printed wiring board and the capacitor element.

  Furthermore, in the present invention, the copper of the anode mounting electrode and the cathode mounting electrode is used as a base material, a nickel layer is provided on the copper, and further a gold plating layer is provided, which is used for general soldering processing. Improves solderability and suppresses the soldering temperature and heating time when the bottom electrode type solid electrolytic capacitor according to the present invention is mounted on other electronic components or electronic devices by soldering. It is possible to suppress the occurrence of poor continuity in the mounting operation of the capacitor on other electronic components or electronic devices.

  According to the present invention, the conductive via hole for inserting the anode lead support is not required on the surface of the printed wiring board, unlike the conventional anode internal electrode, which is electrically connected to the anode lead support. After providing high-temperature solder or conductive adhesive on the printed wiring board and conducting via-holes, insert the end of the unconnected anode lead support to the anode lead, and use the high-temperature solder or conductive adhesive to As in the conventional bottom electrode type solid electrolytic capacitor, there is no direct contact between the end of the anode lead support and the conductive surface of the electrode provided on the printed wiring board. Since it is possible to prevent external force from being applied to the capacitor, it is possible to suppress deterioration of leakage current characteristics of the bottom electrode type solid electrolytic capacitor.

  Further, according to the present invention, anode lead supports are welded to both ends of the anode lead that penetrates the capacitor element, and two conductive via holes into which each anode lead support can be inserted are provided on the printed circuit board. After inserting high-temperature solder or conductive adhesive into the common via hole, insert the end of the unconnected anode lead support body into the anode lead, and electrically connect via high-temperature solder or conductive adhesive, When mounting a capacitor element on a printed wiring board, the parallelism of the capacitor element can be easily achieved, and the anode lead can be prevented from being bent by tilting the capacitor element. Degradation of the leakage current characteristics of the capacitor can be further suppressed.

  Further, according to the present invention, a high-temperature solder having a melting point of 220 ° C. or higher or a conductive adhesive is used, and the copper of the anode mounting electrode and the cathode mounting electrode is used as a base material, and a nickel layer is provided on the copper. Furthermore, by providing a gold plating layer, and making the opening of the cathode conductive via hole equal to or less than the area of the surface of the cathode portion bonded to the printed wiring board, it is possible to suppress the occurrence of short circuit failure due to adhesion of conductive adhesive, etc. In addition to ensuring the bonding strength between the printed wiring board and the capacitor element, it is possible to suppress the occurrence of poor conduction when the bottom electrode type solid electrolytic capacitor is mounted on other electronic components or electronic devices, resulting in deterioration of leakage current characteristics It is possible to realize a bottom electrode type solid electrolytic capacitor capable of suppressing

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure explaining 1st Embodiment of the bottom electrode type solid electrolytic capacitor of this invention, FIG. 1 (a) is sectional drawing, FIG.1 (b) is a bottom view. FIGS. 2A and 2B are views for explaining a second embodiment of the bottom electrode type solid electrolytic capacitor of the present invention, FIG. 2A being a cross-sectional view, and FIG. Sectional drawing explaining the conventional lower surface electrode type solid electrolytic capacitor.

  With reference to the drawings, an embodiment of a bottom electrode type solid electrolytic capacitor of the present invention will be described.

(First embodiment)
FIG. 1 is a diagram for explaining a first embodiment of a bottom electrode type solid electrolytic capacitor of the present invention. FIG. 1A is a cross-sectional view, and FIG. 1B is a bottom view.

  The bottom electrode type solid electrolytic capacitor of the present invention includes a capacitor element 1 from which an anode lead 2 is derived, an anode lead support 4 welded and electrically joined to the anode lead 2, an anode lead support 4 and a conductive member. 8 is provided with an anode conduction via hole 17 whose bottom surface is the conduction surface 11 of the anode mounting electrode 12 provided on the insulating plate 13, which is electrically joined to the insulating plate 13. Further, the cathode portion 19 of the capacitor element 1 and the conductive member 8 A printed wiring board 14 provided with a cathode conductive via hole 16 having the conductive surface 9 of the cathode mounting electrode 10 provided on the insulating plate 13 as a bottom surface, and the capacitor element 1 covering the capacitor element 1 and having an insulating property. And resin 3.

  Further, in the bottom electrode type solid electrolytic capacitor of the present invention, the surface of the insulating board 13 of the printed wiring board 14 on the side where the anode mounting electrode 12 and the cathode mounting electrode 10 are provided is different from the bottom electrode type solid electrolytic capacitor. This is the mounting surface for mounting on the electronic component.

  The capacitor element 1 can be a conventional capacitor element, which is formed by sintering a powder of valve action metal such as tantalum, aluminum, niobium, etc., and forming a porous body made of a sintered body of valve action metal. A dielectric layer, an electrolyte layer, and a cathode layer are sequentially provided on the surface of the porous body, a cathode portion 19 is provided on the bottom surface of the porous body, and the anode lead 2 is led out from one side surface of the porous body. be able to.

  The anode lead 2 can use a metal wire such as a tantalum wire, a tin-plated copper wire, or a nickel wire, and can be appropriately selected.

  The anode lead support 4 can use metals, such as copper, a copper alloy, or an iron nickel alloy, and can select it suitably.

  The exterior resin 3 can be a liquid or solid epoxy resin, a thermosetting resin such as a phenol resin, and can be appropriately selected.

  As the conductive adhesive 5, an adhesive mixed with a material having good conductivity such as silver powder, copper powder, or carbon fiber can be used and can be appropriately selected.

  The conductive member 8 can use a high-temperature solder having a melting point of 220 ° C. or higher, or the conductive adhesive 5 described above, and the upper limit of the melting point and the curing temperature are selected in consideration of the heat resistance of the capacitor element and the like. It can be selected appropriately. For example, the high-temperature solder contains Sn-Ag-Cu, and once it melts at around 230 ° C, the Sn and Cu contained in it chemically react and the melting point changes to 300 ° C or higher. Can do.

  The printed wiring board 14 is provided with the anode mounting electrode 12 and the cathode mounting electrode 10 on one surface of the insulating plate 13 on which the copper layer is provided, and the anode lead support 4 on the other surface of the insulating plate 13. An anode conductive via hole 17 having an opening of an area large enough to be inserted, having a conductive surface 11 of the anode mounting electrode 12 as a bottom surface, a concave cross-sectional shape, and copper plating on the inner surface of the hole. Further, the cathode portion 19 has an opening having an area equal to or smaller than the area to be bonded to the printed wiring board, the conducting surface 9 of the cathode mounting electrode 10 is a bottom surface, and the cross-sectional shape is a concave hole. A cathode conductive via hole 16 subjected to a copper plating process is provided on the inner surface to produce the cathode.

  The size of the opening of the cathode conductive via hole 16 is preferably larger in consideration of the bonding strength between the printed wiring board 14 and the capacitor element 1. However, when the size of the opening is larger than the area of the surface of the cathode portion 19 that is bonded to the printed wiring board, the conductive adhesive 5 may protrude and adhere to the capacitor element 1 to cause a short circuit. In addition, it is necessary to select the dimensions of the cathode mounting electrode 10 in consideration of the dimensions of the electronic component on the capacitor mounting side or the electrode of the electronic device, and the size of the opening is the size of the selected cathode mounting electrode 10. It is preferable to select appropriately considering the dimensions.

  For the insulating plate 13, for example, a plate material of about 0.1 mm such as glass epoxy resin, polyimide resin, or fluororesin can be used and can be selected as appropriate.

  The mounting electrode for anode 12 and the mounting electrode for cathode 10 are provided with a copper layer on one surface of the insulating plate 13 using an existing printed wiring technology, and further provided with a nickel layer on the copper layer, and further with gold Produced by providing a plating layer. As shown in FIG. 1B, the anode mounting electrode 12 and the cathode mounting electrode 10 are electrodes provided on the bottom surface of the bottom electrode type solid electrolytic capacitor for mounting on other electronic components.

  The anode conductive via hole 17 is irradiated with, for example, a laser beam from the surface of the insulating plate 13 where the anode mounting electrode 12 is not installed toward the anode mounting electrode 12 provided on the insulating plate 13, in a predetermined range. After removing the resin of the insulating plate 13, the conductive surface 11 of the anode mounting electrode 12 is exposed, the conductive surface 11 is the bottom surface, and a hole having a concave cross section is formed, and then the inner surface of the hole is subjected to copper plating. Do and make.

  The cathode conductive via hole 16 is irradiated with laser light from the surface of the insulating plate 13 on which the cathode mounting electrode 10 is not installed toward the cathode mounting electrode 10 provided on the insulating plate 13, so that the insulating plate within a predetermined range is provided. 13 is removed, the conductive surface 9 of the cathode mounting electrode 10 is exposed, the conductive surface 9 is the bottom, and a hole having a concave cross-section is formed, and then copper plating is performed on the inner surface of the hole, Make it.

  In the first embodiment, a laser beam is used to make a hole having a concave cross-sectional shape in the insulating plate, but a means for making a hole having a concave cross-sectional shape in the insulating plate uses a laser beam. Other means such as a cutting machine may be used as long as the same effect as the processing can be obtained.

  In the bottom electrode type solid electrolytic capacitor of the first embodiment, the conductive member 8 paste is printed on the anode conductive via hole 17 of the printed wiring board 14 by using, for example, a metal mask. Fill the hole constituting the via hole 17 with the paste of the conductive member 8, and form the layer of the conductive member 8 protruding from the surface of the printed wiring board 14 in the direction extending from the opening of the conductive via hole 17 for anode. .

  Furthermore, the conductive adhesive 5 is printed on the cathode conductive via hole 16 of the printed wiring board 14 using, for example, a metal mask, and the conductive adhesive 5 is filled in the holes constituting the cathode conductive via hole 16. At the same time, a layer of the conductive adhesive 5 protruding from the surface of the printed wiring board 14 is formed in a direction extending from the opening of the cathode conductive via hole 16.

  In the first embodiment, printing means using a metal mask is employed as means for providing the conductive member 8 in the anode conductive via hole 17 and means for providing the conductive adhesive 5 in the cathode conductive via hole 16. The thicknesses of the conductive member 8 and the conductive adhesive 5 protruding from the surface of the printed wiring board 14 can be easily adjusted by changing the thickness of the metal mask. Can be selected as appropriate in consideration of the bonding strength. Note that other installation means may be used as long as the same effect as the printing means using a metal mask can be obtained.

  Next, after the anode lead support 4 is electrically joined to the anode lead 2 of the capacitor element 1 by resistance welding or the like, the end of the anode lead support 4 not connected to the anode lead 2 is connected to the anode conductive via hole. The capacitor element 1 is mounted by inserting the cathode portion 19 of the capacitor element 1 into contact with the conductive adhesive 5 provided in the cathode conductive via hole 16.

  Next, the conductive member 8 is heated and melted or heated and cured using a heating furnace, laser light, or the like, and the anode lead support 4 and the anode conductive via hole 17 are electrically joined, and the anode The lead support 4 and the conductive surface 11 of the anode mounting electrode 12 are electrically joined.

  When high-temperature solder is used for the conductive member 8, it is easy to join the conductive member 8 by processing the surface of the anode lead support 4 facing the printed wiring board 14 and its side surface, such as tin plating. In addition, the bonding strength can be increased.

  Next, the conductive adhesive 5 is heated and cured using a heating furnace, laser light, etc., and the cathode portion 19 of the capacitor element 1 and the cathode conductive via hole 16 are electrically joined, and the cathode mounting electrode 10 It is electrically joined to the conductive surface 9 of.

  Next, an exterior resin 3 is provided so as to cover the capacitor element 1 on the printed wiring board 14, heated and cured, and then molded, and then the printed wiring board 14 and the exterior resin 3 are cut into predetermined dimensions to produce To do.

  With the above-described configuration, when the capacitor element is mounted on the printed wiring board, the end of the anode lead support that is not connected to the anode lead can be inserted into the conductive via hole for the anode. Can offset the difference in height between the surface facing the substrate and the surface of the cathode part, can prevent the curvature of the anode lead welded to the anode lead support, and can suppress the deterioration of leakage current characteristics of the bottom electrode type solid electrolytic capacitor .

  Furthermore, with the above-described configuration, it is possible to ensure the bonding strength between the printed wiring board and the capacitor element, and to prevent the electrical connection between the bonded locations inside the capacitor from causing poor conduction at a general soldering temperature. Therefore, it is possible to realize a bottom electrode type solid electrolytic capacitor capable of suppressing deterioration of leakage current characteristics.

(Second Embodiment)
FIG. 2 is a diagram for explaining a second embodiment of the bottom electrode type solid electrolytic capacitor of the present invention. 2A is a cross-sectional view, and FIG. 2B is a bottom view.

  In the bottom electrode type solid electrolytic capacitor of the present invention, the anode lead 82 penetrating the capacitor element is welded and electrically joined to the capacitor element 81 derived from both sides of the capacitor element and the end of the anode lead 82, respectively. Anode lead support body 84a, anode lead support body 84b, anode lead support body 84a, and conductive member 88a electrically connected with anode member electrode 92a provided on insulating plate 93 with anode as the bottom surface. A conductive via hole 97a for the anode, and a conductive via hole 97b for the anode having the conductive surface 91b of the mounting electrode 92b for the anode provided on the insulating plate 93, the anode lead support 84b being electrically joined by the conductive member 88b. Furthermore, the cathode mounting provided on the insulating plate 93, in which the cathode portion 99 of the capacitor element 81 is electrically joined with the conductive adhesive 85 Having a printed circuit board 94 having a cathode conductive via hole 96 to the bottom surface conduction surface 89 of the electrode 90 to cover the capacitor element 81, and an exterior resin 83 having insulating properties.

  Further, in the bottom electrode type solid electrolytic capacitor of the present invention, the surface of the insulating plate 93 of the printed wiring board 94 on the side provided with the anode mounting electrode 92a, the anode mounting electrode 92b, and the cathode mounting electrode 90 is the bottom electrode type. It becomes a mounting surface when the solid electrolytic capacitor is mounted on another electronic component.

  Capacitor element 81 sinters a powder of valve action metal such as tantalum, aluminum, niobium and the like, forms a porous body made of a sintered body of valve action metal, and then forms a dielectric layer on the surface of the formed porous body. In addition, an electrolyte layer and a cathode layer can be sequentially provided, a cathode portion 99 can be provided on the bottom surface of the porous body, and the anode lead 82 can be led out from both opposing side faces through the porous body.

  For the anode lead 82, a metal wire such as a tantalum wire, a tin-plated copper wire, or a nickel wire can be used, and can be appropriately selected.

  The anode lead support body 84a and the anode lead support body 84b can use metals, such as copper, a copper alloy, or an iron nickel alloy, and can select it suitably.

  As the exterior resin 83, a thermosetting resin such as a liquid or solid epoxy resin or phenol resin can be used, and can be appropriately selected.

  As the conductive adhesive 85, an adhesive mixed with a material having good conductivity such as silver powder, copper powder, or carbon fiber can be used, and can be appropriately selected.

  The conductive member 88a and the conductive member 88b can use a high-temperature solder having a melting point of 220 ° C. or higher, or the above-mentioned conductive adhesive 5, and consider the heat resistance of the capacitor element etc. Can be selected as appropriate. For example, the high-temperature solder contains Sn-Ag-Cu, and once it melts at around 230 ° C, the Sn and Cu contained in it chemically react and the melting point changes to 300 ° C or higher. Can do.

  The printed wiring board 94 is provided with an anode mounting electrode 92a, an anode mounting electrode 92b, and a cathode mounting electrode 90 on one surface of an insulating plate 93, and an anode lead support 84a on the other surface of the insulating plate 93. A conductive via hole for an anode having a conductive surface 91a of the mounting electrode 92a for the anode, a hole having a concave cross-sectional shape, and a copper plating process applied to the inner surface of the hole 97a, an opening having an area enough to insert the anode lead support 84b, a hole 91b having a conductive surface 91b of the anode mounting electrode 92b, and a concave cross section. A conductive via hole 97b for the anode subjected to the copper plating process is provided, and further there is an opening equal to or less than the area of the surface of the cathode portion 99 to be bonded to the printed wiring board, and the conductive surface 89 of the cathode mounting electrode 90 is the bottom surface. ,cross section Jo is a concave hole, provided cathode conductive via holes 96 performing the copper plating on the inner surface of the hole, making.

  In consideration of the bonding strength between the printed wiring board 94 and the capacitor element 81, the size of the opening of the cathode conductive via hole 96 is preferably larger. However, when the size of the opening is larger than the area of the surface of the cathode 99 that is bonded to the printed wiring board, the conductive adhesive 85 may adhere to the capacitor element 1 and cause a short circuit. In addition, it is necessary to select the dimensions of the cathode mounting electrode 90 in consideration of the dimensions of the electronic component on the capacitor mounting side or the electrode of the electronic device, and the size of the opening depends on the size of the selected cathode mounting electrode 90. It is preferable to select appropriately considering the dimensions.

  For the insulating plate 93, for example, a plate material of glass epoxy resin, polyimide resin, fluororesin or the like having a thickness of about 0.1 mm can be used and can be appropriately selected.

  The anode mounting electrode 92a, the anode mounting electrode 92b, and the cathode mounting electrode 90 are provided with a copper layer on one surface of the insulating plate 93 using an existing printed wiring technique, and further on the copper layer. A nickel layer is provided, and a gold plating layer is further provided. As shown in FIG. 2B, the anode mounting electrode 92a, the anode mounting electrode 92b, and the cathode mounting electrode 90 are mounted on other electronic components provided on the bottom surface of the bottom electrode type solid electrolytic capacitor. Electrode.

  The anode conductive via hole 97a is directed to the anode mounting electrode 92a provided on the insulating plate 93 from the surface of the insulating plate 93 where the anode mounting electrode 92a is not installed, for example, by irradiating a laser beam in a predetermined range. After removing the resin from the insulating plate 93 to expose the conductive surface 91a of the anode mounting electrode 92a, the conductive surface 91a is used as the bottom, and a hole having a concave cross section is formed, and then the inner surface of this hole is subjected to copper plating. Do and make.

  The anode conductive via hole 97b is irradiated with, for example, laser light from the surface of the insulating plate 93 where the anode mounting electrode 92b is not installed toward the anode mounting electrode 92b provided on the insulating plate 93, so as to fall within a predetermined range. After removing the resin from the insulating plate 93 to expose the conductive surface 91b of the anode mounting electrode 92b, the conductive surface 91b is used as the bottom surface, and a hole having a concave cross-sectional shape is formed. Do and make.

  The cathode conductive via hole 96 is irradiated with, for example, laser light from the surface of the insulating plate 93 on which the cathode mounting electrode 90 is not installed, toward the cathode mounting electrode 90 provided on the insulating plate 93. After removing the resin from the insulating plate 93 to expose the conductive surface 89 of the cathode mounting electrode 90 and forming a hole with the conductive surface 89 as a bottom surface and a concave cross-sectional shape, copper plating is performed on the inner surface of the hole. Do and make.

  In the second embodiment, a laser beam is used and a hole having a concave cross-sectional shape is formed on the insulating plate. However, a laser beam is used as a means for forming a hole having a concave cross-sectional shape on the insulating plate. Other means such as a cutting machine may be used as long as the same effect as the processing can be obtained.

  In the bottom electrode type solid electrolytic capacitor of the second embodiment, the conductive member 88a paste is printed on the conductive via hole 97a for the anode of the printed wiring board 94 by using, for example, a metal mask, thereby conducting the conductive for the anode. The hole constituting the via hole 97a is filled with the paste of the conductive member 88a, and a layer of the conductive member 88a protruding from the surface of the printed wiring board 94 is formed in a direction extending from the opening of the conductive via hole 97a for the anode. .

  Further, the conductive member 88b paste is printed on the anode conductive via hole 97b of the printed wiring board 94 by using, for example, a metal mask, and the conductive member 88b paste is put in the hole constituting the anode conductive via hole 97b. A layer of the conductive member 88b protruding from the surface of the printed wiring board 94 is formed in a direction extending from the opening of the conductive via hole 97b for anode while filling.

  Further, for example, a conductive adhesive 85 is printed on the cathode conductive via hole 96 of the printed wiring board 94 by using a metal mask, and the conductive adhesive 85 is filled in the holes constituting the cathode conductive via hole 96. At the same time, a layer of conductive adhesive 85 protruding from the surface of the printed wiring board 94 is formed in a direction extending from the opening of the cathode conductive via hole 96.

  In the first embodiment, the conductive adhesive 85 is provided in the means for providing the conductive member 88a in the anode conductive via hole 97a, the means for providing the conductive member 88b in the conductive via hole 97b for anode, and the conductive via hole 96 for the cathode. As a means for providing, a printing means using a metal mask is adopted, and the thicknesses of the conductive member 88a, the conductive member 88b, and the conductive adhesive 85 protruding from the surface of the printed wiring board 94 are as follows. The thickness can be easily adjusted, and can be selected as appropriate in consideration of the bonding strength between the printed wiring board and the capacitor element. Note that other installation means may be used as long as the same effect as the printing means using a metal mask can be obtained.

  Next, the anode lead support 84 a is electrically joined to one end of the anode lead 82 of the capacitor element 81 by resistance welding or the like, and the anode lead support 84 b is resistance to the other end of the anode lead 82. Electrically joined by welding or the like.

  Next, the end of the anode lead support 84a not connected to the anode lead 82 is inserted into the anode conductive via hole 97a, and the end of the anode lead support 84b not connected to the anode lead 82 is used for the anode. The capacitor element 81 is mounted by inserting it into the conductive via hole 97 b and bringing the cathode portion 99 of the capacitor element 81 into contact with the conductive adhesive 85 provided in the conductive via hole 96 for the cathode.

  Next, the conductive member 88a is heated and melted or heated and cured using a heating furnace, laser light, or the like, and the anode lead support 84a and the anode conductive via hole 97a are electrically joined, and the anode The lead support 84a and the conductive surface 91a of the anode mounting electrode 92a are electrically joined.

  Furthermore, the conductive member 88b is heated and melted using a heating furnace, laser light, or the like, or is heated and cured to electrically join the anode lead support 84b and the conductive via hole 97b for the anode, and to connect the anode lead. The conductive surface 91b of the support 84b and the anode mounting electrode 92b is electrically joined.

  When high temperature solder is used for the conductive member 88a and the conductive member 88b, the surface of the anode lead support 84a and the surface of the anode lead support 84b that faces the printed wiring board 94 and the side surface thereof are subjected to processing such as tin plating. As a result, it is easy to join the conductive member 88a and the conductive member 88b, and it is possible to increase the bonding strength.

  Next, the conductive adhesive 85 is heated and cured using a heating furnace, laser light, etc., and the cathode portion 99 of the capacitor element 81 and the conductive via hole 96 for cathode are electrically joined, and the mounting electrode 90 for cathode is used. The conductive surface 89 is electrically joined.

  Next, an exterior resin 83 is provided so as to cover the capacitor element 81 on the printed wiring board 94, heated and cured, and then molded, and then the printed wiring board 94 and the exterior resin 83 are cut into predetermined dimensions to produce To do.

  With the above configuration, when the capacitor element is mounted on the printed wiring board, the end of the anode lead support bonded to both ends of the anode lead that penetrates the capacitor element is connected to the anode lead via hole. And can be inserted into the conductive via hole for the anode, so that the height difference between the surface facing the printed wiring board of the anode lead support and the surface of the cathode portion can be offset, and the parallelism of the capacitor element can be easily obtained. This makes it possible to prevent the bending of the anode lead that may occur due to the inclination of the capacitor element, and to further suppress the deterioration of the leakage current characteristics of the bottom electrode type solid electrolytic capacitor.

  Furthermore, with the above-described configuration, it is possible to ensure the bonding strength between the printed wiring board and the capacitor element, and to prevent the electrical connection between the bonded locations inside the capacitor from causing poor conduction at a general soldering temperature. Therefore, it is possible to realize a bottom electrode type solid electrolytic capacitor capable of suppressing deterioration of leakage current characteristics.

  As mentioned above, although embodiment of this invention was described using drawing, this invention is not restricted to these embodiment, There exists a change of a member and a structure in the range which does not deviate from the meaning of this invention. Are also included in the present invention. That is, it is a matter of course that the present invention also includes various changes and modifications that can be made by those skilled in the art.

1, 41, 81 Capacitor element 2, 42, 82 Anode lead 3, 43, 83 Exterior resin 4, 44, 84a, 84b Anode lead support 5, 45, 85 Conductive adhesive 8, 88a, 88b Conductive member 9 , 11, 501, 502, 503, 504, 89, 91a, 91b Conductive surfaces 10, 50, 90 Mounting electrodes for cathode 12, 52, 92a, 92b Mounting electrodes for anode 13, 53, 93 Insulating plates 14, 54, 94 Printed circuit boards 16, 96 Conductive via holes for cathodes 17, 97a, 97b Conductive via holes for anodes 19, 59, 99 Cathode part 49 Internal electrode for cathode 51 Internal electrode for anode

Claims (7)

  Capacitor element having a cathode portion provided on a porous body made of a valve action metal from which an anode lead is led out, an anode lead support body having one end welded to the anode lead and electrically joined thereto, and the anode lead An anode having an anode internal electrode electrically joined to a support and a cathode internal electrode electrically joined to the cathode portion on one surface and electrically joined to the anode internal electrode And a printed wiring board having a cathode mounting electrode electrically joined to the cathode internal electrode on the other surface, and a bottom electrode type having an insulating exterior resin containing the capacitor element In the solid electrolytic capacitor, a hole having a concave cross section is provided at the position of the internal electrode for the anode, and a conductive via hole for the anode subjected to plating is provided on the inner surface of the hole. Provided electroconductive member in the hole, the lower surface electrode type solid electrolytic capacitor characterized by being electrically connected to the anode mounting electrode and the anode lead support and the anode conductive via hole and the anode lead support.   An anode lead is led out from the opposite side surfaces of the capacitor element, and the anode lead support provided at both ends of the anode lead and the anode conduction via hole are electrically joined via the conductive member. The bottom electrode type solid electrolytic capacitor according to claim 1.   An opening having an area equal to or smaller than the area of the surface of the cathode to be bonded to the printed wiring board is provided at the position of the internal electrode for the cathode, the cross-sectional shape is a concave hole, and the inner surface of the hole was plated A conductive via hole for cathode is provided, and a conductive adhesive is provided in the conductive via hole for cathode, and the conductive via hole for cathode and the cathode portion are electrically joined via the conductive adhesive. The bottom electrode type solid electrolytic capacitor according to claim 1 or 2.   4. The bottom electrode type solid electrolytic capacitor according to claim 1, wherein the conductive member is a solder having a melting point of 220 [deg.] C. or higher.   4. The bottom electrode type solid electrolytic capacitor according to claim 1, wherein the conductive member is a conductive adhesive.   6. The anode mounting electrode and the cathode mounting electrode are made of copper as a base material, a nickel layer is provided on the surface of the base material, and a gold plating layer is further provided. A bottom electrode type solid electrolytic capacitor as described in 1.   The step of forming the anode mounting electrode and the cathode mounting electrode on the bottom surface, and providing a hole having a concave cross-sectional shape in the printed wiring board, plating the inner surface of the hole, and producing the cathode conductive via hole; A step of providing the conductive member in the conductive via hole for anode, a step of providing the conductive adhesive in the conductive via hole for cathode, and an end of the anode lead support not connected to the anode lead for the anode Inserting into the conductive via hole and electrically joining the anode lead support and the conductive via hole for anode through the conductive member; and the conductive via hole for cathode and the cathode portion through the conductive adhesive The method of manufacturing a bottom electrode type solid electrolytic capacitor according to claim 1, further comprising:

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