JP2009218486A - Method of manufacturing solid electrolytic capacitor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solid electrolytic capacitor improving productivity with a good yield. <P>SOLUTION: A plurality of T notches are formed in a plate like supporting equipment 4, a lead 2 of a capacitor element 3 is placed at the center of each T notch placed adjoining the other notches, and a portion folded is further pressure bonded to wrap around the lead 2. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a solid electrolytic capacitor, and more particularly to a method for manufacturing a solid electrolytic capacitor in which a plurality of capacitor elements connected to a support are anodized.

  In recent years, with increasing performance and functionality of digital devices such as computers, mobile phones, and game consoles, MPUs and memories of computer motherboards, servers, etc. have been increasing in speed and frequency, and are being installed in devices. Even in a solid electrolytic capacitor of an electronic component, low ESR characteristics are required.

  FIG. 2 is a perspective view showing a capacitor element used for the solid electrolytic capacitor. A capacitor element 3 is formed by planting an anode lead wire (hereinafter referred to as a lead wire) 2 made of a valve metal on a molded body 1 made of a metal powder having a valve action such as tantalum, aluminum, titanium, niobium or the like. .

  In general, in order to perform a plurality of processes simultaneously on a capacitor element, the tip of a lead wire planted on the capacitor element is connected to a flat plate support made of metal by a method such as welding, and the dielectric layer and An oxide film, a manganese dioxide layer as a solid electrolyte layer, a carbon layer as a cathode layer, and a silver paste layer, a cathode portion as the outer periphery of the capacitor element, and an anode portion as the lead wire, and lead out of the anode and cathode The capacitor element is used in a state of being connected to the support until it is arranged and connected to the frame.

Here, a general method for manufacturing a solid electrolytic capacitor will be described. As shown in FIG. 2, the capacitor element is formed by adding a binder to a valve action metal powder such as tantalum, granulating, and pressing and molding the lead wire 2 in a planted state to form a molded body 1 having a predetermined shape. The unit capacitor element is formed. The capacitor element 3 is baked at a high temperature in a high vacuum to form a porous sintered body with a lead wire of the capacitor element. 3 to 8 show the process of manufacturing the solid electrolytic capacitor, FIG. 3 is a perspective view of the process of connecting the capacitor element to the support, FIG. 4 is a schematic diagram of the dielectric layer forming process, and FIG. FIG. 6 is a perspective view of the positive cathode extraction process, FIG. 7 is a schematic view of the resin mold exterior process, and FIG. 8 is a schematic view of the extraction terminal molding process. As shown in FIG. 3, a plurality of capacitor elements made of a porous sintered body are connected to a plate-like support 4 via a lead wire 2 by means of an upper electrode 13 and a lower electrode 14, and then 4, the capacitor element 3 is immersed in the chemical conversion solution 5 in the chemical conversion treatment tank, and a voltage is applied between the cathode plate 6 and the flat support 4 in the chemical conversion solution 5 to thereby form the capacitor element. An oxide film serving as a dielectric is formed on the surface of 3. Subsequently, immersion in a manganese nitrate solution and heat treatment are repeated to form a manganese dioxide (MnO ₂ ) layer 7 as a solid electrolyte on the surface of the oxide film as shown in FIG. On the manganese dioxide layer 7, a carbon layer 8 and a silver paste layer 9 are sequentially formed, and a capacitor element 3 having a cathode portion as an outermost layer is formed. Next, as shown in FIG. 6, an electrode lead frame 10 is arranged on each of the lead wire planted on the capacitor element 3 and the cathode portion on the outer periphery of the capacitor element, and the anode external lead is connected by means such as welding. Then, after connecting the cathode external lead to the cathode part on the outer periphery of the capacitor element with a conductive adhesive or the like, the whole except for a part of the lead frame 10 is covered with an epoxy resin 11 as shown in FIG. 7, and further shown in FIG. Thus, the solid electrolytic capacitor 12 is completed by using the lead frame exposed from the epoxy resin coating portion as a cathode by cutting and bending.

  Here, in the method of connecting a plurality of capacitor elements to a flat support, various techniques for improving capacitor characteristics are disclosed.

  For example, in Patent Document 1, a plurality of capacitor elements are fixed to a metal horizontal bar (also referred to as a support) by welding anode terminal bars (also referred to as lead wires) integrally protruding from the capacitor elements. Thus, the solid electrolytic capacitor in which the capacitor element is immersed in the treatment liquid for forming the insulating layer and the various treatment liquids for forming the cathode layer in a state where the capacitor elements are mounted at appropriate pitch intervals in the longitudinal direction of the horizontal bar. A manufacturing method is disclosed.

  Patent Document 2 discloses a method for correcting the displacement of the capacitor element surface continuously welded to the elongated plate-like body in the direction perpendicular to the longitudinal direction of the plate-like body as a method corresponding to the warp of the plate-like material (also referred to as a support). It is disclosed.

  Furthermore, in Patent Document 3, when welding a thin stainless steel plate (also called a support) and a tantalum wire (also called a lead wire), there is a difference in the melting point of each material (stainless steel about 1500 ° C., tantalum about 3000 ° C.). For this reason, there is disclosed a method of rotating an electrode in order to prevent welding conditions from being very difficult, fluctuations in the welding conditions frequently occurring, and warping of a thin plate of stainless steel and welding strength with a tantalum wire from being lowered.

  On the other hand, for example, Patent Document 4 proposes a technique for increasing the bonding area between a lead wire and a molded body. The shape of the lead wire is a foil shape with a specified thickness, or the method of forming irregularities on the surface of the foil to further increase the contact area and the method of providing multiple through holes in the lead wire in the lead wire embedded part It is effective for improvement.

Japanese Patent Laid-Open No. 06-163331 JP 09-239547 A JP 07-323378 A JP 2000-012387 A

  According to the prior art, the capacitor characteristic (ESR) is improved by increasing the contact area between the metal powder and the lead wire in the lead wire embedded portion, but the plate shape is a plate material of a different material from the lead wire having an increased cross-sectional area. Due to the difference in melting point, it was extremely difficult to join the support to the support tool because the capacitor element dropped out of the connection part by resistance welding.

  In addition, if a plurality of capacitor elements are welded in a non-uniform state and joined to a flat plate-like support, the welded portion is further welded in the subsequent oxide film, manganese dioxide layer formation, carbon layer, silver paste layer formation step, etc. As a result, the capacitor element may fall off and the yield may be reduced.

  In general, the flat plate support is made of stainless steel or aluminum plate, etc., and the lead wire made of valve action metal is a dissimilar metal. In resistance welding of two metals, melting of a material having a low melting point is performed under certain conditions. As a result, as if the material having a high melting point is melted, the material adheres to the material having a low melting point, but is peeled off by a stress of several N when stress such as peeling is applied.

  Under the circumstances described above, an object of the present invention is to provide a method of manufacturing a solid electrolytic capacitor having high capacity, excellent high frequency characteristics, improved characteristics such as low ESR, good yield, and improved productivity.

  In order to solve the above-described problems, a method of manufacturing a solid electrolytic capacitor according to the present invention includes a method of manufacturing a solid electrolytic capacitor in which capacitor elements are aligned and connected to a flat support, and a dielectric layer and a solid electrolyte layer are formed. A plurality of T-shaped notches are provided on the lower side of the flat plate-shaped support, and lead wires planted in the capacitor element are disposed between the notches so as to wrap the lead wires. The method includes a step of folding and pressing the lower side portion of the support.

  The solid electrolytic capacitor manufacturing method of the present invention is a method of manufacturing a solid electrolytic capacitor in which a capacitor element is aligned and connected to a flat support, and a dielectric layer and a solid electrolyte layer are formed. The method includes a step of providing a plurality of cut and bent portions on a lower side portion of the support, and inserting and crimping a lead wire planted on the capacitor element into the cut and bent portion.

  The method for manufacturing a solid electrolytic capacitor of the present invention may include a step of welding the lead wire of the crimping portion to the support tool after the lead wire is pressure-bonded to the support tool.

  In addition, the method for manufacturing a solid electrolytic capacitor of the present invention may include a step of welding the lead wire in the vicinity of the crimping portion to the support tool after the lead wire is pressure-bonded to the support tool.

  Furthermore, the method for producing a solid electrolytic capacitor of the present invention is the method for producing a solid electrolytic capacitor in which capacitor elements are aligned and connected to a plate-shaped support, and a dielectric layer and a solid electrolyte layer are formed. A lead wire planted on the capacitor element is disposed on the lower side of the support, a contact plate is disposed on the lead wire, the contact plate is bent along the lead wire, and then the support plate and the support The method includes the step of welding the tool.

  According to the present invention, since the periphery of the lead wire is covered with the material of the support tool at the connection portion between the flat plate-like support tool and the lead wire, the connection is more robust against the stress of pulling, peeling, and twisting. The state can be maintained, and a stable connection can be made to the support regardless of the cross-sectional area or shape of the lead wire.

  Next, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 shows a schematic diagram in which the lower side portion of the support according to the first embodiment of the present invention is folded and crimped onto a lead wire, and FIGS. 9 to 11 connect the capacitor element to the support according to the first embodiment of the present invention. FIG. 9 shows a front view of the step of placing the lead wire planted in the capacitor element on the support provided with a notch, and FIG. 10 shows the step of bending the lower side of the support to the lead wire side, 10A is a front view, FIG. 10B is a cross-sectional view taken along the line AA in FIG. 10A, and FIG. 11 is a process of folding and crimping the lower side portion of the support onto the lead wire. (A) is a front view, FIG.11 (b) shows the sectional view on the AA line of Fig.11 (a). As shown in FIG. 9, a T-shaped notch is continuously provided in the lower side portion of the flat support 4 made of a metal such as aluminum or stainless steel by pressing, cutting, etching or the like. The number of notches is preferably one more than the number of capacitor elements 3 arranged on the support, and is preferably provided at equal intervals. Next, a binder is added to the valve action metal powder and granulated, and the lead wire is planted using the same lead wire as the granulated metal powder, and then pressed, molded and sintered to a predetermined A capacitor element 3 having a shape (see FIG. 2) is formed, and the lead wire 2 is disposed at the center of adjacent T-shaped notches.

  Next, as shown in FIG. 10, the lower side portion, which is the remaining portion of the T-shaped notch adjacent to the support (becomes an inverted T-shaped portion), is led around the position where the lead wire 2 of the capacitor element 3 is disposed. Bend to the wire side. Furthermore, as shown in FIG. 11, the folding lead wire is crimped from both ends so that the outer periphery of the lead wire 2 is wrapped by the lower side of the support (see FIG. 1).

(Embodiment 2)
13A and 13B show a process of connecting a capacitor element to the support according to the second embodiment of the present invention. FIG. 13A is a front view, and FIG. 13B is an AA line in FIG. A cross-sectional view is shown. A plurality of cut and bent portions (also referred to as louvers, lances, and bridges) are provided on the lower side of the flat support 4 by pressing or the like. The depth of the cut and bent portion is preferably such that the lead wire can be easily inserted. As shown in FIG. 13, after the lead wire 2 of the capacitor element 3 is inserted into the cut and bent portion of the support tool 4, the cut and bent portion around the lead wire of the support tool is crimped.

(Embodiment 3)
FIG. 14 shows a process of connecting a capacitor element to the support according to Embodiment 3 of the present invention, FIG. 14 (a) is a front view, and FIG. 14 (b) is a side view. In the present embodiment, the lead wire crimped to the support in the first embodiment or the second embodiment is further connected by welding. That is, after the lead wire is crimped at the lower side portion of the support tool, the lead wire 2 in the vicinity of the crimp portion is welded to the support tool 4 by the upper electrode 13 and the lower electrode 14 as shown in FIG. The welding location may be on the upper side or the lower side as long as it is in the vicinity of the crimping portion of the lead wire 2 and the support 4. Here, the direct method of resistance welding in which the electrodes are arranged vertically is shown, but the welding method is not limited to this method.

(Embodiment 4)
FIG. 15 shows a process of connecting a capacitor element to the support according to Embodiment 4 of the present invention, FIG. 15 (a) is a front view, and FIG. 15 (b) is a side view. In the present embodiment, the lead wire crimped to the support in the first embodiment or the second embodiment is further connected to the crimping portion by welding. That is, after the lead wire is crimped at the lower side portion of the support, the lead wire 2 and the support 4 are welded by the upper electrode 13 and the lower electrode 14 at the crimp portion as shown in FIG.

(Embodiment 5)
FIG. 16 shows a process of connecting a capacitor element to the support according to the fifth embodiment of the present invention, FIG. 16 (a) is a front view, and FIG. 16 (b) is a drawing in which a contact plate is arranged on a lead wire. 16A is a cross-sectional view taken along the line AA in FIG. 16A, and FIG. 16C is a cross-sectional view taken along the line AA in FIG. 16A, and FIG. AA line sectional view of Drawing 16 (a) is shown. In the present embodiment, as shown in FIG. 16B, the lead wire 2 of the capacitor element is disposed on the flat support 4 and the contact plate 15 made of the same material as that of the flat support 4 is disposed. . Next, as shown in FIG. 16C, the contact plate 15 is bent along the lead wire 2 from the upper surface. Thereafter, as shown in FIG. 16 (d), the contact plate 15 and the flat support 4 are welded by the upper electrode 13 and the lower electrode 14.

  T-shaped notches are provided at equal intervals on the lower side of a flat plate-like support made of aluminum having a thickness of 0.5 mm by pressing. Next, a binder element is added to the valve action metal powder, granulated, and a capacitor element that is pressed, molded, and sintered in a state where the lead wire is planted using the same lead wire as the granulated metal powder. The lead wire was formed and arranged at the center of the T-shaped notch adjacent to each other. As the lead wire, an elliptical lead wire having a minor axis of 0.35 mm and a major axis of 1.35 mm was used.

  Next, after folding the lower side, which is the remaining portion of the adjacent T-shaped notch of the support, with the lead wire disposed at the center, 2.0 mm of the tip of the lead is wrapped in the lower side of the support Folded lead wires were crimped from both ends.

(Comparative example)
A lead wire planted on the same capacitor element as used in the example was connected to the support by resistance welding without providing a notch in the support used in the example.

(Connection strength measurement)
FIG. 12 is a schematic diagram showing connection strength measurement. The tensile strength was defined as the force applied when the capacitor element 3 connected to the support was disconnected from the support 4 when the capacitor element 3 was pulled downward as shown in FIG. The bending strength is the force applied when the capacitor element 3 is disconnected from the support tool 4 when the capacitor element is pushed in the direction perpendicular to the support tool as shown in FIG. . Table 1 shows the results of measuring the tensile strength and bending strength of 10 examples and comparative examples.

  The tensile strength of the example was about 15N stronger on average than the welding of the conventional comparative example, and the bending strength was stable at 30N. In addition, after performing the dielectric layer forming process on the capacitor element connected to the support according to the embodiment, the capacitance (CV) measurement results are the same as in the prior art, and the connection by welding and the connection according to the present invention are electrically connected to the capacitor element. There was no problem.

  In the embodiment, the lead wire having an elliptical cross section is described. However, the lead wire shape is not particularly limited to this shape, and a round shape used in a known technique may be used.

The schematic diagram which carried out the crimping | compression-bonding of the lower side part of the support tool of Embodiment 1 of this invention on a lead wire. The perspective view which shows the capacitor | condenser element used for a solid electrolytic capacitor. The perspective view of the process of connecting a capacitor | condenser element to the support tool in the middle of manufacture of a solid electrolytic capacitor. The schematic diagram of the dielectric material layer formation process of the process in the middle of manufacture of a solid electrolytic capacitor. The cross-sectional schematic diagram of the capacitor | condenser element after the cathode layer formation of the process in the middle of manufacture of a solid electrolytic capacitor. The perspective view of the positive electrode extraction process of the middle process of manufacture of a solid electrolytic capacitor. The schematic diagram of the resin mold exterior process of the manufacture process of a solid electrolytic capacitor. The schematic diagram of the terminal shaping | molding process of the manufacturing process of a solid electrolytic capacitor. The front view of the process of arrange | positioning the lead wire planted to the capacitor | condenser element to the support which provided the notch of the process of connecting a capacitor | condenser element to the support of Embodiment 1 of this invention. The figure which shows the process of bending the lower side part of the support tool of the process of connecting a capacitor | condenser element to the support tool of Embodiment 1 of this invention to the lead wire side, FIG.10 (a) is a front view, FIG.10 (b) AA line sectional view of Drawing 10 (a). The figure which shows the process of folding and crimping | bonding the lower side part of the support tool on a lead wire of the process of connecting a capacitor | condenser element to the support tool of Embodiment 1 of this invention, FIG.11 (a) is a front view, FIG.11 (b) is FIG. The AA sectional view taken on the line of Fig.1 (a). The schematic diagram which shows connection strength measurement. The figure which shows the process of connecting a capacitor | condenser element to the support tool of Embodiment 2 of this invention, Fig.13 (a) is a front view, FIG.13 (b) is the sectional view on the AA line of Fig.13 (a). The figure which shows the process of connecting a capacitor | condenser element to the support tool of Embodiment 3 of this invention, Fig.14 (a) is a front view, FIG.14 (b) is a side view. The figure which shows the process of connecting a capacitor | condenser element to the support tool of Embodiment 4 of this invention, Fig.15 (a) is a front view, FIG.15 (b) is a side view. The figure which shows the process of connecting a capacitor | condenser element to the support tool of Embodiment 5 of this invention, FIG.16 (a) is a front view, FIG.16 (b) is FIG.16 (a) which arrange | positions a contact plate on a lead wire. FIG. 16C is a cross-sectional view taken along the line AA of FIG. 16A, and FIG. 16D is a cross-sectional view taken along the line A-A of FIG. The AA sectional view taken on the line of a).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Molded body 2 Lead wire 3 Capacitor element 4 Support tool 5 Chemical conversion liquid 6 Cathode plate 7 Manganese dioxide layer 8 Carbon layer 9 Silver paste layer 10 Lead frame 11 Epoxy resin 12 Solid electrolytic capacitor 13 Upper electrode 14 Lower electrode 15

Claims (5)

  In a method of manufacturing a solid electrolytic capacitor in which capacitor elements are aligned and connected to a flat support member to form a dielectric layer and a solid electrolyte layer, a plurality of T-shaped cuts are formed on the lower side of the flat support member. Providing a notch, placing a lead wire planted in the capacitor element between the notches, and folding and crimping a lower side portion of the support so as to wrap the lead wire. Manufacturing method of electrolytic capacitor.   In a method for manufacturing a solid electrolytic capacitor in which a capacitor element is aligned and connected to a flat support and a dielectric layer and a solid electrolyte layer are formed, a plurality of bent portions are provided on a lower side of the flat support. A method of manufacturing a solid electrolytic capacitor comprising the steps of inserting and crimping a lead wire planted on the capacitor element into the cut and bent portion.   The method for manufacturing a solid electrolytic capacitor according to claim 1, further comprising a step of welding the lead wire of the crimping portion to the support tool after the lead wire is crimped to the support tool.   The method for manufacturing a solid electrolytic capacitor according to claim 1, further comprising a step of welding the lead wire in the vicinity of the crimping portion to the support tool after the lead wire is crimped to the support tool.   In a method of manufacturing a solid electrolytic capacitor in which a capacitor element is aligned and connected to a flat support, and a dielectric layer and a solid electrolyte layer are formed, the capacitor element is planted on a lower side of the flat support. A solid plate comprising: a step of arranging the lead wire, placing a contact plate on the lead wire, bending the contact plate along the lead wire, and welding the contact plate and the support. Manufacturing method of electrolytic capacitor.

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