JP5167014B2 - Solid electrolytic capacitor - Google Patents

Description

  The present invention relates to a solid electrolytic capacitor including a porous sintered body made of, for example, tantalum or niobium.

  As a conventional solid electrolytic capacitor, for example, the one disclosed in Patent Document 1 is known. FIG. 4 is a cross-sectional view showing an example of a solid electrolytic capacitor. The solid electrolytic capacitor X shown in the figure includes a substantially rectangular parallelepiped porous sintered body 91, an anode wire 911, an anode mounting terminal 95, a cathode mounting terminal 96, and a sealing resin 98. On the surface of the porous sintered body 91, a dielectric layer 92, a solid electrolyte layer 93, and a conductor layer 94 are laminated. The solid electrolytic capacitor X is configured to be surface-mountable on a circuit board, for example, using an anode mounting terminal 95 and a cathode mounting terminal 96 having flat mounting surfaces. The anode mounting terminal 95 includes a support portion 951 that supports the tip of the anode wire 911, and a bottom portion 952 that holds the support portion 951 and is partially exposed outside the sealing resin 98. In this solid electrolytic capacitor X, the porous sintered body 91 and the anode wire 911 are inclined with respect to the mounting surface so that the support portion 951 and the anode wire 911 are in contact with each other. The inclined corners 912 of the porous sintered body 91 are in contact with and supported by the cathode mounting terminals 96.

  However, in such a solid electrolytic capacitor X, since the contact area between the porous sintered body 91 and the cathode mounting terminal 96 is small, an unreasonably large force may be applied to the corner portion 912. For this reason, the corner portion 912 may be damaged. In addition, since the contact area between the porous sintered body 91 and the cathode mounting terminal 96 is small, there is a problem that the electrical resistance between the both becomes large.

JP 2008-108932 A

  An object of the present invention is to provide a solid electrolytic capacitor that has been conceived under the circumstances described above and has a structure in which defects are unlikely to occur.

  The solid electrolytic capacitor provided by the present invention includes a porous sintered body made of a valve metal, an anode wire protruding from the porous sintered body, a support portion for supporting the anode wire, and electrical connection with the support portion. An anode mounting terminal having a bottom portion, a dielectric layer and a solid electrolyte layer laminated on the surface of the porous sintered body, and a cathode mounting terminal electrically connected to the solid electrolyte layer. The terminal is a solid electrolytic capacitor having a flat mounting surface for mounting on an external mounting board, and the cathode mounting terminal is formed so as to move away from the mounting surface as the anode mounting terminal is approached. The porous sintered body is supported by the inclined surface.

  According to such a configuration, even if the porous sintered body is inclined with respect to the mounting surface, the contact area between the porous sintered body and the inclined surface is supported by the inclined surface. It tends to be relatively large. For this reason, the solid electrolytic capacitor has a structure in which an excessively large force is not easily applied between the porous sintered body and the inclined surface, and a defect is not easily generated. Furthermore, since the contact area between the porous sintered body and the inclined surface becomes relatively large, it is possible to suppress the electric resistance generated between the porous sintered body and the inclined surface. ing.

  In a preferred embodiment of the present invention, the cathode mounting terminal includes a receiving surface that stands up with respect to the inclined surface at a position farther from the anode mounting terminal than the inclined surface. According to such a configuration, since the positional displacement of the porous sintered body is prevented by the receiving surface at the time of manufacture, defects are less likely to occur. Furthermore, since the porous sintered body bites into the cathode mounting terminal, it is preferable in reducing the size of the solid electrolytic capacitor.

  In a preferred embodiment of the present invention, the inclined surface is formed so as to overlap the mounting surface as viewed in the thickness direction of the mounting surface. According to such a configuration, the inclined surface can be easily formed by cutting the surface of the cathode mounting terminal opposite to the mounting surface.

  In a preferred embodiment of the present invention, a sealing resin is provided to cover the porous sintered body, the anode wire, the anode mounting terminal, and the cathode mounting terminal, and the cathode mounting terminal includes the mounting surface. A resin contact surface covered with the sealing resin is formed at a position closer to the anode mounting terminal than the mounting surface and closer to the porous sintered body than the mounting surface. The mounting surface is formed so as to overlap the resin contact surface as viewed in the thickness direction. According to such a configuration, since the resin contact surface is held by the sealing resin, the cathode mounting terminal is difficult to drop off from the sealing resin. For this reason, the solid electrolytic capacitor has a structure in which defects are less likely to occur.

  In a preferred embodiment of the present invention, the cathode mounting terminal includes an inclined plate that is inclined with respect to the mounting surface so as to be farther from the mounting surface as the anode mounting terminal is closer to the anode mounting terminal. The surface on the porous sintered body side is the inclined surface. More preferably, the inclined plate is covered with the sealing resin. According to such a configuration, it is possible to easily form the inclined plate by bending a part of the cathode mounting terminal. Furthermore, since the inclined plate is held by the sealing resin, the cathode mounting terminal is difficult to drop off from the sealing resin.

  In preferable embodiment of this invention, the whole surface of the said inclined surface is adhere | attached with the porous sintered compact via the adhesive material which has electroconductivity. According to such a configuration, since the porous sintered body is supported by the entire surface of the inclined surface, the force applied between the porous sintered body and the inclined surface is preferably dispersed. For this reason, the solid electrolytic capacitor has a structure in which an excessively large force is not easily applied between the porous sintered body and the inclined surface, and a defect is not easily generated.

  Other features and advantages of the present invention will become more apparent from the detailed description given below with reference to the accompanying drawings.

  FIG. 1 is a sectional view showing a first embodiment of a solid electrolytic capacitor according to the present invention. A solid electrolytic capacitor A1 shown in FIG. 1 includes a porous sintered body 1, an anode wire 11, a dielectric layer 2, a solid electrolyte layer 3, a conductor layer 4, an anode mounting terminal 5, a cathode mounting terminal 6, and a conductive adhesive layer. 7 and the sealing resin 8 are provided so that they can be surface-mounted on the circuit board. The solid electrolytic capacitor A1 is used for applications such as noise removal and power supply assistance in an electric circuit, for example. Further, FIG. 1 shows an x direction and a z direction orthogonal to each other. The z direction coincides with the thickness direction of the cathode mounting terminal 6. The solid electrolytic capacitor A1 is formed in a substantially rectangular shape when viewed in the z direction, and the longitudinal direction of the solid electrolytic capacitor A1 coincides with the x direction.

  The porous sintered body 1 is made of a valve action metal such as niobium or tantalum and has a structure in which a large number of pores are formed. The porous sintered body 1 is manufactured, for example, by subjecting a fine powder of a valve action metal such as niobium or tantalum to pressure molding and then subjecting this molded body to a sintering treatment. By this sintering treatment, fine powders of the valve action metal are sintered, and the porous sintered body 1 having a large number of pores is formed. The porous sintered body 1 is a substantially rectangular parallelepiped, and its longitudinal direction x ′ is inclined with respect to the x direction.

  The anode wire 11 is made of a valve metal such as niobium or tantalum and protrudes from the porous sintered body 1 along the x ′ direction. The anode wire 11 is an integrated product in a state in which a part of the anode wire 11 is intruded into the fine powder when the fine powder of the valve action metal described above is pressed.

  The dielectric layer 2 is formed on the surface of the porous sintered body 1 and is made of an oxide of a valve action metal. The dielectric layer 2 covers the pores of the porous sintered body 1. The dielectric layer 2 is formed, for example, by subjecting the porous sintered body 1 to anodization in a state where the porous sintered body 1 is immersed in a chemical conversion solution of phosphoric acid aqueous solution.

  The solid electrolyte layer 3 is laminated on the dielectric layer 2 and is formed so as to fill the pores of the porous sintered body 1. The solid electrolyte layer 3 is made of, for example, manganese dioxide or a conductive polymer. When the solid electrolytic capacitor A1 is used, charges are accumulated at the interface between the solid electrolyte layer 3 and the dielectric layer 2.

  The conductor layer 4 has a structure in which, for example, a graphite layer and an Ag layer are stacked, and covers the solid electrolyte layer 3.

  The anode mounting terminal 5 is made of, for example, Cu or Ni, and includes a support portion 51 and a plate-like bottom portion 52 connected to the support portion 51. The support portion 51 is formed, for example, in a rod shape extending along the z direction, the upper end in the z direction is joined to the tip of the anode wire 11, and the lower end in the z direction is joined to the bottom 52. Yes. The bottom 52 is provided with a flat anode-side mounting surface 53 that is exposed from the sealing resin 8.

  The cathode mounting terminal 6 is a plate-like member made of, for example, Cu or Ni, and includes a cathode side mounting surface 61, a receiving surface 62, and an inclined surface 63. The cathode side mounting surface 61 is a flat surface exposed from the sealing resin 8 and connected to the circuit board. The receiving surface 62 is a surface that stands up with respect to the cathode side mounting surface 61. The inclined surface 63 is formed such that the closer to the anode mounting terminal 5 in the x direction, the farther from the cathode side mounting surface 61 in the z direction. The inclined surface 63 overlaps the cathode-side mounting surface 61 in the z-direction view over the entire length in the x-direction. The end of the inclined surface 63 far from the anode mounting terminal 5 in the x direction is connected to the receiving surface 62. The receiving surface 62 and the inclined surface 63 are formed, for example, by scraping a part of the cathode mounting terminal 6.

  The conductive adhesive layer 7 is a layer formed by solidifying a conductive adhesive applied to the entire surface of the inclined surface 63, and adheres the inclined surface 63 and the conductor layer 4. The conductive adhesive constituting the conductive adhesive layer 7 is, for example, an Ag paste.

  The sealing resin 8 is made of, for example, an epoxy resin, and covers and protects the porous sintered body 1, the anode wire 11, the anode mounting terminal 5, and the cathode mounting terminal 6.

  Next, the operation of the solid electrolytic capacitor A1 having the above configuration will be described.

  According to this embodiment, the porous sintered body 1 is supported by the entire surface of the inclined surface 63. For this reason, the stress generated by the weight or thermal deformation of the porous sintered body 1 is easily dispersed, and an excessively large force is hardly applied to the porous sintered body 1. Therefore, the solid electrolytic capacitor A1 has a structure in which the porous sintered body 1 is not easily damaged and defective.

  Further, according to the present embodiment, since the contact area is relatively large, the electrical resistance generated between the porous sintered body 1 and the cathode mounting terminal 6 is also suppressed. For this reason, it is possible to suppress the power consumption of the solid electrolytic capacitor A1. Furthermore, since heat generation can be suppressed, thermal deformation of the porous sintered body 1 and the cathode mounting terminal 6 can be suppressed. Therefore, the solid electrolytic capacitor A1 has a structure that is less likely to cause defects.

  Further, according to the present embodiment, the inclined surface 63 can be easily formed by scraping the surface located on the opposite side of the cathode side mounting surface 61 in the z direction of the plate-like cathode mounting terminal 6.

  Moreover, according to this embodiment, since the position of the porous sintered body 1 can be prevented by the receiving surface 62 during manufacture, defects are less likely to occur.

  Further, according to the present embodiment, since the porous sintered body 1 has a structure in which a part of the porous sintered body 1 bites into the cathode mounting terminal 6, the solid electrolytic capacitor A1 can be easily downsized.

  In addition, according to the present embodiment, the inclined surface 63 is formed so as to be recessed with respect to the surface located on the opposite side of the cathode-side mounting surface 61 in the z direction. This adhesive is difficult to protrude from the inclined surface 63. For this reason, it is difficult for the conductive adhesive to unreasonably adhere to the range excluding the inclined surface 63 of the cathode mounting terminal 6. Therefore, the solid electrolytic capacitor A1 has a structure that is less likely to cause defects.

  2 and 3 show another embodiment of the present invention. In these drawings, the same or similar elements as those in the above embodiment are denoted by the same reference numerals as those in the above embodiment, and description thereof is omitted.

  FIG. 2 is a sectional view showing a second embodiment of the solid electrolytic capacitor according to the present invention. In the solid electrolytic capacitor A2 shown in FIG. 2, a resin contact surface 64 is provided at the end of the cathode mounting terminal 6 on the anode mounting terminal 5 side in the x direction. The resin contact surface 64 is recessed with respect to the cathode side mounting surface 61 so as to approach the porous sintered body 1 in the x direction, and is covered with the sealing resin 8. Further, the bottom 52 is provided with a resin contact surface 54 that is recessed with respect to the anode-side mounting surface 53 in the z direction.

  In such a solid electrolytic capacitor A <b> 2, the resin contact surface 64 is covered with the sealing resin 8, so that the cathode mounting terminal 6 is not easily dropped from the sealing resin 8. Further, since the resin contact surface 54 is covered with the sealing resin 8, the anode mounting terminal 5 is not easily detached from the sealing resin 8.

  FIG. 3 is a sectional view showing a third embodiment of the solid electrolytic capacitor according to the present invention. In the solid electrolytic capacitor A3 shown in FIG. 3, the cathode mounting terminal 6 has a configuration including an inclined plate 65 formed by bending. The inclined plate 65 is inclined with respect to the cathode side mounting surface 61 so as to be farther from the cathode side mounting surface 61 in the z direction as it approaches the anode mounting terminal 5 in the x direction, and the inclined plate 65 is porous in the z direction. The surface on the sintered body 1 side is an inclined surface 63. Further, in the solid electrolytic capacitor A3, the resin contact surface 54 is provided on the anode mounting terminal 5 as in the case of the solid electrolytic capacitor A2.

  In such a solid electrolytic capacitor A3, the inclined plate 65 can be easily formed by bending a part of the cathode mounting terminal 6. Further, in the solid electrolytic capacitor A3, since the inclined plate 65 bites into the sealing resin 8, the cathode mounting terminal 6 is difficult to drop off from the sealing resin.

  The solid electrolytic capacitor according to the present invention is not limited to the above-described embodiment. The specific configuration of each part of the solid electrolytic capacitor according to the present invention can be varied in design in various ways. In the above embodiment, the anode wire 11 extends along x ′ in the longitudinal direction of the porous sintered body 1, but the direction of the anode wire 11 may be shifted from the longitudinal direction x ′.

It is sectional drawing which shows an example of the solid electrolytic capacitor which concerns on 1st Embodiment of this invention. It is sectional drawing which shows an example of the solid electrolytic capacitor which concerns on 2nd Embodiment of this invention. It is sectional drawing which shows an example of the solid electrolytic capacitor which concerns on 3rd Embodiment of this invention. It is sectional drawing which shows an example of the conventional solid electrolytic capacitor.

Explanation of symbols

A1, A2, A3 Solid electrolytic capacitor x (solid electrolytic capacitor) longitudinal direction x ′ (longitudinal direction of porous sintered body) direction z (thickness) direction 1 porous sintered body 2 dielectric layer 3 solid electrolyte layer 4 conductive Body layer 5 Anode mounting terminal 6 Cathode mounting terminal 7 Conductive adhesive layer 8 Sealing resin 11 Anode wire 51 Support portion 52 Bottom portion 53 Anode-side mounting surface 54 Resin contact surface 61 Cathode-side mounting surface 62 Receiving surface 63 Inclined surface 64 Resin contact surface 65 Inclined plate

Claims (7)

A porous sintered body made of a valve metal,
An anode wire protruding from the porous sintered body;
An anode mounting terminal having a support part for supporting the anode wire and a bottom part electrically connected to the support part;
A dielectric layer and a solid electrolyte layer laminated on the surface of the porous sintered body;
A cathode mounting terminal electrically connected to the solid electrolyte layer;
With
The cathode mounting terminal is a solid electrolytic capacitor having a flat mounting surface for mounting on an external mounting board,
The cathode mounting terminal includes an inclined surface formed so as to be farther from the mounting surface as it approaches the anode mounting terminal.
A solid electrolytic capacitor, wherein the porous sintered body is supported on the inclined surface.   The solid electrolytic capacitor according to claim 1, wherein the cathode mounting terminal includes a receiving surface that stands up with respect to the inclined surface at a position farther from the anode mounting terminal than the inclined surface.   The solid electrolytic capacitor according to claim 1, wherein the inclined surface is formed so as to overlap the mounting surface when viewed in the thickness direction of the mounting surface. A sealing resin covering the porous sintered body, the anode wire, the anode mounting terminal and the cathode mounting terminal;
The cathode mounting terminal is provided with a resin contact surface covered with the sealing resin at a position closer to the anode mounting terminal than the mounting surface and closer to the porous sintered body than the mounting surface. Has been
The solid electrolytic capacitor according to claim 3, wherein the inclined surface is formed so as to overlap the resin contact surface when viewed in the thickness direction of the mounting surface.   The cathode mounting terminal has an inclined plate that is inclined with respect to the mounting surface so that it is farther from the mounting surface as it approaches the anode mounting terminal, and the surface of the inclined plate on the porous sintered body side is The solid electrolytic capacitor according to claim 1 or 2, wherein the inclined surface is formed. A sealing resin covering the porous sintered body, the anode wire, the anode mounting terminal and the cathode mounting terminal;
The solid electrolytic capacitor according to claim 5, wherein the inclined plate is covered with the sealing resin.   The solid electrolytic capacitor according to claim 1, wherein the entire surface of the inclined surface is bonded to the porous sintered body via a conductive adhesive.

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