JP4466094B2 - Electrolytic capacitor manufacturing method - Google Patents

Description

The present invention relates to method of manufacturing an electrolytic capacitor having a capacitor element having an anode portion and a cathode portion.

As a conventional electrolytic capacitor, there is a solid electrolytic capacitor as described in Patent Document 1, for example. The solid electrolytic capacitor described in this document includes a base substrate and a capacitor element fixed on the base substrate. The capacitor element has an aluminum substrate (anode portion) having an anodized film formed on the surface, and a capacitor portion (cathode portion) formed on the surface of a partial region of the aluminum substrate.
JP-A-6-267802

  By the way, in the solid electrolytic capacitor including the capacitor element as described above, in order to increase the capacitance of the solid electrolytic capacitor, the capacitor element may be placed on the base substrate (connected body) in a stacked state. However, in recent years, from the viewpoint of mass production, it is strongly desired to efficiently perform such a capacitor element mounting operation.

An object of the present invention is to provide a method of manufacturing an electrolytic capacitor which can improve the efficiency of the work of placing the stacked capacitor element onto the connection member.

The method of manufacturing the electrolytic capacitor of the present invention, the object to be connected with a positive land and a cathode land, surface made of a valve metal substrate of the dielectric layer is formed foil, prepared and an anode portion having an anode terminal And a capacitor element in which a plurality of cathode portions are formed by forming a solid electrolyte layer on the surface of the dielectric layer and a conductor layer on the solid electrolyte layer in the regions on both ends of the anode terminal in the anode portion. forming a capacitor element having an anode portion and a cathode portion, a tatami no step folding with respect to the anode terminal as bent anode terminal of the anode portions each cathode portions opposing the folding portion of the anode terminal connected to positive land of the object to be connected, it is characterized in that comprising the step of connecting the cathode portion to the negative land of the object to be connected.

In such an electrolytic capacitor manufacturing method of the present invention, the capacitor element is first folded with respect to the anode terminal so that the cathode portions face each other. Then, the bent portion of the anode terminal is connected to the anode land of the connected body by laser welding, for example, and the cathode portion is connected to the cathode land of the connected body, for example, by a conductive adhesive. Thus, by placing the capacitor element having a plurality of cathode parts on the connected body in a folded state, the capacitor element is placed in a stacked state on the connected body. For this reason, compared with the case where capacitor elements each having one cathode portion are stacked on the connected body one by one, the number of times of stacking the capacitor elements themselves on the connected body can be reduced. Further, in order to accurately superimpose the cathode portions of the capacitor element, it is only necessary to accurately determine the bending position of the anode terminal, and the handling of the capacitor element is very simple. As described above, it is possible to efficiently perform the operation of placing the capacitor element on the connected body in a stacked state.

Preferably, in the step of folding the capacitor element with respect to the anode terminal, tatami no folding an anode terminal as the bent portions of the anode terminal is substantially V-shaped. Thus, for example, when the bent portion of the anode terminal is connected to the anode land of the body to be connected by laser welding, the bent portion of the anode terminal can be securely fixed to the anode land while minimizing the welding location. it can. Thereby, it becomes possible to perform the operation | work which mounts a capacitor | condenser element in a laminated state on a to-be-connected body still more efficiently.

  According to the present invention, the capacitor element is folded with respect to the anode terminal so that the cathode portions face each other, and in this state, the bent portion of the anode terminal is connected to the anode land of the connected body, and the cathode portion is covered. Since the connection is made to the cathode land of the connection body, the efficiency of the work of placing the capacitor element on the connection body in a laminated state can be improved. This makes it possible to improve workability in the production of electrolytic capacitors.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of an electrolytic capacitor and a manufacturing method thereof according to the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a plan view of a principal part showing a solid electrolytic capacitor as one embodiment of the electrolytic capacitor according to the present invention, FIG. 2 is a cross-sectional view taken along the line II-II in FIG. 1, and FIG. It is III sectional view. In each figure, the solid electrolytic capacitor 1 of the present embodiment includes a substrate 2, a capacitor element 3 placed on the substrate 2, and a resin mold portion 4 for fixing the capacitor element 3.

  The board | substrate 2 is a printed circuit board made from an epoxy resin, for example. Copper anode lands 5 and cathode lands 6 are printed on the upper surface of the substrate 2, and copper anode lands 7 and cathode lands 8 are printed on the lower surface of the substrate 2. The substrate 2 is also formed with via holes 9 that electrically connect the anode lands 5 and 7 and via holes 10 that electrically connect the cathode lands 6 and 8. A plurality of (here, two) anode lands 5 and 7 are formed on one end side of the substrate 2.

  The capacitor element 3 includes an anode part 12, a cathode part 13, and an insulating layer 14. The anode portion 12 is electrically connected to the anode land 5 of the substrate 2, and the cathode portion 13 is electrically connected to the cathode land 6 of the substrate 2. At this time, the anode terminal 11 is joined to the anode land 5 by YAG laser spot welding or the like, and the cathode portion 13 is joined to the cathode land 6 by the conductive adhesive S. The insulating layer 14 electrically insulates the anode portion 12 and the cathode portion 13 from each other.

  Such a capacitor element 3 is fixed to the substrate 2 in a state where a flat plate as shown in FIG. 4 is folded with respect to the anode terminal 11. FIG. 4 is a plan view showing the capacitor element sheet 3S before processing, and FIG. 5 is an enlarged cross-sectional view showing in detail a partial structure of the capacitor element sheet 3S.

In each figure, the capacitor element 3 has a foil-like aluminum substrate 15, and the surface of the aluminum substrate 15 is roughened (enlarged) by an etching process. An insulating aluminum oxide (Al ₂ O ₃ ) film 16 is formed on the roughened surface of the aluminum substrate 15 by anodic oxidation. The thickness of the aluminum substrate 15 is, for example, about 90 to 100 μm, and the film thickness of the aluminum oxide film 16 is, for example, about several nm to several tens of nm.

  The aluminum base 15 and the aluminum oxide coating 16 as a whole form the anode portion 12 described above. The anode section 12 includes two anode bodies 17 and a plurality (two in this case) of anode terminals 11 integrated with the anode bodies 17 so as to connect the anode bodies 17 to each other.

  A solid electrolyte layer 18 containing a conductive polymer compound is formed on the surface of each anode body 17 (aluminum oxide film 16). This solid electrolyte layer 18 is impregnated in a recess 15a formed by a roughened aluminum substrate 15. The solid electrolyte layer 18 is formed by impregnation in the recess 15a in a monomer state and then chemical oxidation polymerization or electrolytic oxidation polymerization. On the solid electrolyte layer 18, a graphite paste layer 19 and a silver paste layer 20 are sequentially formed by any one of a screen printing method, a dipping method (dip method), and a spray coating method.

  These solid electrolyte layer 18, graphite paste layer 19, and silver paste layer 20 form the cathode portion 13. These two cathode portions 13 are respectively formed on the surfaces of the regions on both ends of the anode terminal 11 in the anode portion 12 so as to sandwich the two anode terminals 11 therebetween. The cathode portion 13 is formed in a state where the anode terminal 11 is masked, for example.

  Further, the insulating layer 14 made of an epoxy resin or the like is formed on the surface (aluminum oxide film 16) of both end portions of each anode terminal 11 by a screen printing method or the like.

  When the solid electrolytic capacitor 1 is manufactured using such a flat capacitor element 3, first, the capacitor element 3 is placed in an anode so that the two cathode portions 13 face each other as shown in FIGS. The terminal 11 is folded around a predetermined position. At this time, the bending position of the anode terminal 11 is determined so that the respective cathode portions 13 of the capacitor element 3 are overlapped without being shifted. The capacitor element 3 is preferably folded with respect to the anode terminal 14 such that the bent portion 11a of the anode terminal 11 is substantially V-shaped.

  Then, in a state where the anode terminal 11 of the folded capacitor element 3 is slightly bent toward the substrate 2, the cathode portion 13 is fixed to the cathode land 6 of the substrate 2, and the bent portion 11a of the anode terminal 11 is fixed to the substrate. 2 to the anode land 5. Specifically, the lower cathode portion 13 of the capacitor element 3 is joined to the cathode land 6 by the conductive adhesive S, and the two cathode portions 13 of the capacitor element 3 are joined by the conductive adhesive S. Further, the aluminum substrate 15 that forms the anode terminal 11 of the capacitor element 3 is joined to the anode land 5 by welding. At this time, by making the bent portion 11a of the anode terminal 11 substantially V-shaped, the welding location of the anode terminal 11 can be minimized, and the anode terminal 11 can be easily welded.

  Thereafter, the resin mold portion 4 is formed by injection, transformer molding, or the like, and the capacitor element 3 placed on the substrate 2 is fixed by molding. In addition, as resin which forms the resin mold part 4, an epoxy resin etc. are used.

  As described above, in the present embodiment, one flat capacitor element 3 is folded with respect to the anode terminal 11, and the capacitor element 3 is placed on the substrate 2 in this state. It is not necessary to separate the two cathode portions 13 of the element 3. When the two cathode portions 13 are separated, it is necessary to stack two capacitor elements on the substrate 2, which is troublesome and it is difficult to align the cathode portions 13 of the two capacitor elements. There is a possibility that the upper and lower cathode portions 13 are misaligned. This may lead to deterioration of characteristics as a capacitor. In the present embodiment, the capacitor element 3 is disposed on the substrate 2 in a stacked state by simply placing one capacitor element 3 on the substrate 2. Further, since the two cathode portions 13 of the capacitor element 3 can be accurately aligned only by bending the desired position of the anode terminal 11, handling of the capacitor element 3 is very simple. Thereby, the operation of placing and fixing the capacitor element on the substrate 2 in a stacked state can be efficiently performed in a short time. Therefore, it is advantageous for mass production of solid electrolytic capacitors.

  In the above embodiment, one capacitor element 3 is placed on the substrate 2, but two or more capacitor elements 3 may be stacked on the substrate 2. In this case, the bent portions 11a of the anode terminals 11 of the two capacitor elements 3 are joined together by welding or the like, but compared to a case where capacitor elements having one cathode portion are stacked one by one, The number of times the capacitor element itself is laminated on the substrate 2 is clearly reduced.

  In the above embodiment, the capacitor element 3 having the two cathode portions 13 is folded only once. However, the present invention is not particularly limited to this configuration. For example, three or more cathode portions are anode terminals as capacitor elements. It is also possible to prepare the capacitor elements connected in series via the capacitor, fold the capacitor element in a zigzag manner a plurality of times, and bond the bent portions of the anode terminals to the anode lands provided on the substrate 2.

  6 is a plan view of a principal part showing a solid electrolytic capacitor as another embodiment of the electrolytic capacitor according to the present invention, FIG. 7 is a sectional view taken along line VII-VII in FIG. 6, and FIG. It is a VIII-VIII line sectional view. In the drawing, the same reference numerals are given to the same or equivalent members as those of the above-described embodiment, and the description thereof is omitted.

  In the figure, a solid electrolytic capacitor 30 of this embodiment includes a substrate 31 and two capacitor elements 32A and 32B arranged on the substrate 31 in a stacked state. The substrate 31 includes anode lands 5 and 7 and cathode lands 6 and 8, and a plurality (two in this case) of anode lands 5 and 7 are formed on both ends of the substrate 31.

  Similarly to the capacitor element 3 in the above-described embodiment, the capacitor elements 32 </ b> A and 32 </ b> B have an anode part 12 having two anode terminals 11 and two cathode parts 13, and are folded with respect to the anode terminal 11. It is formed by. At this time, the capacitor elements 32 </ b> A and 32 </ b> B are arranged such that the cathode portions 13 are alternately stacked on the substrate 31. That is, one cathode part 13 of the capacitor element 32A is sandwiched between the two cathode parts 13 of the capacitor element 32B, and one cathode part 13 of the capacitor element 32B is sandwiched between the two cathode parts 13 of the capacitor element 32A. It is in a state. The lower cathode portion 13 of the capacitor element 32A is joined to the cathode land 6 by the conductive adhesive S, and the cathode portion 13 of the capacitor element 32A and the cathode portion 13 of the capacitor element 32B are electrically conductive adhesive. Joined by S. The bent portion 11a of the anode terminal 11 of the capacitor element 32A is joined to the anode land 5 on one end side of the substrate 31 by welding, and the bent portion 11a of the anode terminal 11 of the capacitor element 32B is joined to the substrate 31 by welding. Is joined to the anode pad 5 on the other end side.

  In such a solid electrolytic capacitor 30 as well, it is possible to improve the efficiency of the work of mounting and fixing the capacitor elements on the substrate 31 in a stacked state.

  In addition, this invention is not limited to the said embodiment. For example, the solid electrolytic capacitor of the above embodiment has a so-called multi-terminal type capacitor element in which a plurality of anode terminals 11 between two cathode portions 13 are present. This can also be applied to a capacitor element having one anode terminal 11. Furthermore, although the solid electrolytic capacitor of the above embodiment fixes the capacitor element to the substrate, the present invention is also applicable to a so-called lead frame type capacitor in which the capacitor element is fixed to the lead frame.

It is a principal part top view which shows one Embodiment of the electrolytic capacitor concerning this invention. It is the II-II sectional view taken on the line of FIG. It is the III-III sectional view taken on the line of FIG. It is a top view which shows the state before the process of the capacitor | condenser element shown in FIG. FIG. 5 is an enlarged sectional view showing in detail a partial structure of the capacitor element shown in FIG. 4. It is a principal part top view which shows other embodiment of the electrolytic capacitor concerning this invention. It is the VII-VII sectional view taken on the line of FIG. It is the VIII-VIII sectional view taken on the line of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Solid electrolytic capacitor, 2 ... Board | substrate (to-be-connected body), 3 ... Capacitor element, 5 ... Anode land, 6 ... Cathode land, 11 ... Anode terminal, 11a ... Bending part, 12 ... Anode part, 13 ... Cathode part, DESCRIPTION OF SYMBOLS 15 ... Aluminum base | substrate (valve metal base | substrate), 16 ... Aluminum oxide film (dielectric layer), 17 ... Anode main body, 18 ... Solid electrolyte layer, 19 ... Graphite paste layer, 20 ... Silver paste layer (conductor layer), 30 ... Solid electrolytic capacitor, 31 ... Substrate (connected body), 32A, 32B ... Capacitor element.

Claims (2)

Preparing an object to be connected having an anode land and a cathode land, and an anode part comprising a foil-like valve metal substrate having a dielectric layer formed on the surface and having an anode terminal ;
In end regions of the anode terminal before Symbol anode portion, said dielectric layer capacitor element in the solid electrolyte layer and the solid electrolyte layer and a conductor layer formed respectively to form a plurality of cathode portion on the surface of the Forming a step;
It said capacitor element having the anode part and the cathode part, and tatami no step folding relative to the anode terminal such that the respective cathode portions bent is the anode terminal of the anode portion is opposed,
Method of manufacturing an electrolytic capacitor connected to the bent portions of the front Symbol anode terminal to the positive land of the object to be connected, characterized in that it comprises the step of connecting the cathode portion to the negative land of the object to be connected. In the step of folding said capacitor element to the anode terminal, the production of electrolytic capacitors according to claim 1, wherein the bent portions of the anode terminal and wherein said anode terminal folded free it to be substantially V-shape Way .

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