JP2006059855A - Chip-type electrolytic capacitor and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a chip-type electrolytic capacitor wherein mold flashing can be prevented on the mounting surface of anode and cathode terminals, and to provide its manufacturing method. <P>SOLUTION: The chip-type electrolytic capacitor is provided with a capacitor 1 from which an anode lead wire 4 is led, an anode terminal 5 connected with the anode lead wire 4, a cathode terminal 2 connected with the cathode of the capacitor 1 by means of a conductive adhesive agent 3, and an insulating external resin 9 to cover the capacitor 1 by exposing a part of the anode terminal 5 and a part of the cathode terminal 2. An electrically insulating holding member 8 is provided to prevent mutual deformation by mechanically connecting the anode terminal 5 and the cathode terminal 2 with each other on the board mounting side. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electronic component packaged with a resin and a manufacturing method thereof, and more particularly to a chip-type electrolytic capacitor suitable as a surface-mounted capacitor having a bottom electrode structure and a manufacturing method thereof.

  In recent years, electronic devices have become smaller and higher in performance, and capacitors are required to be further reduced in size and capacity. By limiting the electrode terminals to the mounting surface of the product, the internal structure of the capacitor can be made more efficient and the capacity can be increased. A product of the bottom electrode structure type as shown in FIG.

  FIG. 5 is a cross-sectional view showing a conventional chip electrolytic capacitor of a surface mount type and a bottom electrode structure type. In the figure, a capacitor element 21 is connected to a cathode terminal 22 via a conductive adhesive 23. Further, the anode lead wire 24 drawn out from the capacitor element 21 is connected to the anode bending raised portion 26 of the anode terminal 25 by a technique such as welding.

  Here, a method of forming the anode terminal will be described with reference to FIG. As best shown in the figure, the anode terminal 25 has a T-shape formed so that a so-called lower surface electrode portion 27 and an anode bending raising portion 26 along the mounting surface intersect at a right angle. Further, the lower surface electrode portion 27 includes a mounting surface side portion 29 that forms a plane bent through a 180-degree bent portion 28, and a connecting portion 30 provided to face the mounting surface side portion 29. One end of the connecting portion 30 is The anode is bent and communicated with one end of an anode bending raising portion 26 that is bent upright. Further, the T-shaped anode terminal 25 is stamped and bent by pressing from a single metal plate, and does not have a connection portion even at the intersection of the T-shape.

  In order to form such an anode terminal, as shown by an arrow 31, one metal plate is bent by about 90 degrees by press molding. By this bending, the anode bending raising portion 26 is formed. Next, as shown by an arrow 32, bending is performed at about 180 degrees. By this bending, the terminal portion of the mounting surface is formed. Finally, as shown by the arrow 33 in both bent portions, a crushing process is performed, and the portion where the thickness is increased in the form where two plates are overlapped by bending 180 degrees is reduced to 1 to 1 of the original plate thickness. About 1.3 times. This processing prevents the anode terminal 25 from coming into contact with the cathode layer on the outer periphery of the capacitor element. Then, as shown in FIG. 5, the capacitor element 21, the cathode terminal 22, and the anode terminal 25 are covered with an exterior resin 37 made of an insulating resin.

  A technique of a chip-type electrolytic capacitor having such a bottom electrode structure and an anode terminal having a T-shaped cross section is disclosed in Patent Document 1, for example.

JP 2004-55889 A

  However, in a conventional bottom electrode structure type chip type electrolytic capacitor, as shown in FIG. 7, when the injection molding is performed by transfer molding, the positive / cathode terminal mounting surface is slightly lifted from the surface of the mold that comes into contact. Then, the exterior resin enters the gap and mold flash as shown in FIG. 8 occurs.

  This will be described with reference to the details of the drawings. In FIG. 7, when the anode terminal 25 and the cathode terminal 22 are sandwiched between the upper mold 34 and the lower mold 35, the deformation indicated by the arrow may occur. When the exterior resin enters the gap, the exterior resin 37 wraps around the mounting surfaces of the anode terminal 25 and the cathode terminal 22 as shown in the bottom view of FIG. As a result, there has been a problem that a poor electrical connection occurs between the positive / negative terminal and the land of the substrate.

  In this situation, an object of the present invention is to provide a chip type electrolytic capacitor capable of preventing the occurrence of mold flash on the mounting surfaces of the anode and cathode terminals and a method for manufacturing the same.

  The chip-type electrolytic capacitor of the present invention includes a capacitor element from which an anode lead wire is derived, an anode terminal connected to the anode lead wire, and a cathode terminal connected to the cathode of the capacitor element via a conductive adhesive. And a chip-type electrolytic capacitor comprising a part of the anode terminal and a part of the cathode terminal exposed to cover the capacitor element and covering the capacitor element, wherein the anode terminal and the cathode terminal are connected to the substrate mounting side. An electrically insulating holding member is provided so as to be mechanically connected to each other and prevent mutual deformation. This holding member brings the mounting surface into close contact with the surface of the mold when the anode and cathode terminal portions of the lead frame are sandwiched between the upper and lower molds of injection molding.

  The holding member may be made of a non-metal having the same color as the exterior resin. Then, while maintaining electrical insulation, it is recognized in the same manner as the exterior resin in image recognition at the time of mounting, and can be easily distinguished from the mounting surfaces of the anode and cathode terminals.

  Further, the manufacturing method of the chip type electrolytic capacitor of the present invention includes a capacitor element from which an anode lead wire is derived, an anode terminal connected to the anode lead wire, and a cathode of the capacitor element connected via a conductive adhesive. A negative electrode terminal, and a part of the positive electrode terminal and an insulating exterior resin covering the capacitor element by exposing a part of the negative electrode terminal, and mechanically connecting the positive electrode terminal and the negative electrode terminal A method of manufacturing a chip-type electrolytic capacitor in which an electrically insulating holding member is provided so as to prevent mutual deformation, wherein the holding is performed using a lead frame in which a pair of the anode terminal and the cathode terminal is arranged at a constant pitch. The member connects the anode terminal and the cathode terminal in each of the pair, and performs exterior resin molding in a state where the member is arranged continuously over the plurality of pairs. And butterflies. This method prevents the deformation of the anode terminal and the cathode terminal by reliably and easily connecting between the anode terminal and the cathode terminal as a common holding member for a plurality of elements arranged in parallel.

  The holding member may be sandwiched between upper and lower molds of the molding machine and pressed against one surface of the mold together with the mounting surfaces of the anode terminal and the cathode terminal during the molding of the exterior resin. By this method, the mounting surface of the terminal is brought into close contact with the surface of the mold to prevent the generation of a gap.

  And after the said exterior resin molding, it is good to cut | disconnect the part of the said holding member which protruded between the adjacent exterior resin moldings. By this method, the surplus portion is removed by cutting from the holding member that has acted in common with respect to the plurality of juxtaposed elements.

  According to the present invention, since the positive / cathode terminal is connected by the holding member, one or both of the positive / cathode terminal are not easily deformed. Also, during injection molding by transfer molding, the mounting surface of the positive / negative electrode terminal is pressed against one mold surface without any gap. As a result, the exterior resin is less likely to enter the gap between the mold surfaces that come into contact with the mounting surface of the positive / cathode terminals, preventing mold flash, resulting in an electrical connection between the terminals and the board lands. Connection failure can be avoided.

  In addition, the holding member of the present invention is the same color as the exterior resin, and only the terminals strongly reflect the illumination light during image processing in the mounting device on the electric circuit board, so that the image processing is not adversely affected.

  Since the cut surface of the holding member exposed from the side surface is non-metallic, electrical contact with the adjacent product can be prevented during mounting.

  That is, according to the present invention, it is possible to provide a chip-type electrolytic capacitor in which mold flash does not easily occur on the terminal surface and a method for manufacturing the same.

  Next, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a sectional view showing a chip type electrolytic capacitor of the present invention. 2 shows a lead frame and a holding member used in the chip-type electrolytic capacitor of FIG. 1, FIG. 2 (a) is a plan view thereof, and FIG. 2 (b) is a sectional view taken along line AA. FIG. 3 is a cross-sectional view showing a state of injection molding by transfer molding of the chip type electrolytic capacitor of the present invention. FIG. 4 is a perspective view showing a state of the chip-type electrolytic capacitor of the present invention after molding of the outer resin.

  As shown in FIG. 1, the cathode terminal 2 is bonded to the cathode layer of the capacitor element 1 with a conductive adhesive 3. The anode lead wire 4 drawn out from the capacitor element 1 is disposed and welded to the anode bending raising portion 6 bent at a right angle from the anode terminal 5. As shown in FIG. 2, the cathode terminal 2 and the anode terminal 5 are previously provided with holding members 8 that connect the two at the stage of the lead frame 7. The holding member 8 is provided so as to continuously connect the adjacent pairs of anode and cathode terminals arranged at a constant pitch, and the holding member 8 has the same color as the exterior resin 9 (see FIG. 1). Made of non-metal. At this time, an engineering plastic such as an epoxy resin or a liquid crystal polymer is easy to use as the holding member 8, but it is particularly important that the holding member 8 has the same color as the exterior resin and has high electrical insulation. In FIG. 2, the holding member 8 is formed so as to surround a part of the anode bending raised portion 6 on the anode terminal side with respect to the lead frame 7 and is formed so that the end portion is sandwiched from above and below on the cathode terminal side. Has been.

  Then, the capacitor element 1, the cathode terminal 2, the anode terminal 5, and the holding member 8 are covered with an exterior resin 9 made of an insulating resin. As shown in FIG. 3, when molding the exterior resin by transfer molding, the upper mold 12 and the lower mold 13 sandwich the holding member 8 so that the mounting surfaces of the cathode terminal 2 and the anode terminal 5 are attached to the upper mold 12. Make contact with the surface without any gaps.

  After the exterior resin molding, as shown in FIG. 4, when the excess lead frame 7 is cut, the holding member 8 protruding from the exterior resin is also cut along the two-dot chain line 10. Then, the two surfaces 11a and 11b which are product side surfaces were cut with a dicing saw to obtain the chip type electrolytic capacitor of the present embodiment. With such a structure and manufacturing method, mold flash can be prevented from occurring on the terminal surfaces of the anode and the cathode.

  The present invention is not specialized for a bottom electrode structure type product related to a chip-type electrolytic capacitor, but can be used when manufacturing a chip-type component that implements a resin sheath.

Sectional drawing which shows the chip type electrolytic capacitor of this invention. The lead frame and holding member which are used for the chip type electrolytic capacitor of the present invention are shown, FIG. 2A is a plan view thereof, and FIG. Sectional drawing which shows the state of the injection molding by the transfer mold of the chip type electrolytic capacitor of this invention. The perspective view which shows the state after exterior resin molding of the chip-type electrolytic capacitor of this invention. Sectional drawing which shows the conventional chip-type electrolytic capacitor. The front view which shows the formation method of the anode terminal used for the conventional chip type electrolytic capacitor. Sectional drawing which shows the state of the injection molding by the transfer mold in the conventional chip type electrolytic capacitor. The bottom view which shows the state which the mold flash generate | occur | produced in the conventional chip type electrolytic capacitor.

Explanation of symbols

1,21 Capacitor element 2,22 Cathode terminal 3,23 Conductive adhesive 4,24 Anode lead wire 5,25 Anode terminal 6,26 Anode bending raising portion 7 Lead frame 8 Holding member 9, 37 Exterior resin 10 Two-dot chain line 11a, 11b Two surfaces 12, 34 Upper die 13, 35 Lower die 27 Lower surface electrode portion 28 Bending portion 29 Mounting surface side portion 30 Connecting portion 31, 32, 33 Arrow 36 Mold flash

Claims (5)

  A capacitor element from which an anode lead wire is derived; an anode terminal connected to the anode lead wire; a cathode terminal connected to a cathode of the capacitor element via a conductive adhesive; a part of the anode terminal; In a chip-type electrolytic capacitor comprising an insulating exterior resin in which a part of the cathode terminal is exposed and the capacitor element is covered, the anode terminal and the cathode terminal are mechanically connected on the substrate mounting side to deform each other A chip-type electrolytic capacitor, wherein an electrically insulating holding member is provided so as to prevent the   The chip-type electrolytic capacitor according to claim 1, wherein the holding member is made of a nonmetal having the same color as the exterior resin.   A capacitor element from which an anode lead wire is derived; an anode terminal connected to the anode lead wire; a cathode terminal connected to a cathode of the capacitor element via a conductive adhesive; a part of the anode terminal; An insulating exterior resin in which a part of the cathode terminal is exposed to cover the capacitor element, and the anode terminal and the cathode terminal are mechanically connected to prevent mutual deformation. A method of manufacturing a chip-type electrolytic capacitor in which a holding member is provided, wherein a lead frame in which a pair of the anode terminal and the cathode terminal is arranged at a constant pitch is used, and the holding member is an anode terminal and a cathode terminal in each of the pair A chip type electrolytic capacitor manufacturing method is characterized in that exterior resin molding is performed in a state of being connected so as to be continuous over a plurality of pairs.   The holding member is sandwiched between upper and lower molds of the molding machine at the time of molding the exterior resin, and is pressed against one surface of the mold together with the mounting surfaces of the anode terminal and the cathode terminal, A method for manufacturing a chip-type electrolytic capacitor according to claim 3.   5. The method for manufacturing a chip-type electrolytic capacitor according to claim 3, wherein after the exterior resin molding, the portion of the holding member that protrudes between adjacent exterior resin molded bodies is cut.

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