JPH07272987A - Manufacturing method of solid electrolytic capacitor and cutting device for anode terminal using the same - Google Patents

Abstract

PURPOSE:To provide a manufacturing method for a solid electrolytic capacitor wherein a chip piece can be welded in the state surely positioned on a lead frame and a capacitor of larger capacity is obtained. CONSTITUTION:Multiple capacitor elements containing a chip piece 2 and an anode terminal projected from the chip piece 2 are continuously connected, and a cutting blade 6 is downed with the anode terminal kept in between to cut the anode terminal, so that falling of the cutting edge 6 is stopped at the position the blade surface of cutting blade 6 is away from the anode terminal, and then the cutting blade is raised so that the blade surface of cutting blade follows the cross section of the anode terminal, thus a separation process for separating capacitor elements is constituted. In addition, a transportation process where the chip piece of capacitor element separated in the separation process is held and transported, and the tip part of anode terminal is made contact to a lead frame 11, and a connection process where the capacitor element transported in the transportation process is, by bonding the contact point between the anode terminal and the lead frame 11, connected to the lead frame 11, are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid electrolytic capacitor (hereinafter, simply referred to as "capacitor") manufacturing apparatus and manufacturing method.

[0002]

2. Description of the Related Art Conventionally, this type of capacitor is manufactured as follows. First, as shown in FIG. 1, particles of valve-acting metal such as tantalum or niobium are molded and fired into a porous chip piece 2 in a state in which an anode rod 1 made of metal such as tantalum or niobium is projected. A plurality of chip pieces 2 are attached by fixing the anode rods 1 in the longitudinal direction of the horizontal bar 3 made of metal such as stainless steel at appropriate pitches by welding or the like, and are attached to the surface of the chip pieces 2 in this state. , A dielectric such as tantalum pentoxide, a solid electrolyte layer such as manganese dioxide, and a conductor layer made of metal such as silver are sequentially formed.

Next, a plurality of chip pieces 2 as the capacitor elements formed as described above are individually separated from the horizontal bar 3 by cutting the anode rod 1 with a punching press or the like, and then the adsorption pad 21 is used. The upper surface of the chip piece 2 is adsorbed and held, and the chip piece 2 is conveyed while being positioned on one of the lead terminals 22a extended to the lead frame 22.
The suction surface of the suction pad 21 is the chip piece 2
In order to reliably suck and hold the upper surface of the chip, it is possible to follow the upper surface of the chip piece 2. Further, as shown in FIG. 10, in a state where the chip piece 2 is adsorbed and held by the adsorption pad 21, the anode rod 1 and the lead terminal 22a are pressed so as to be sandwiched by the two electrode rods 23, and the electrode rods 23 are energized. By doing so, the anode rod 1 is welded to the lead terminal 22a. Then, the chip piece 2 and the other lead terminal 22b are connected via a metal wire such as gold, and in this state, the resin mold portion 24 is molded so as to cover the chip piece 2 and the lead terminals 22a, 22b with epoxy resin or the like. After that, the lead frame 22 is punched and bent by a press molding machine or the like to separate the lead frame 22 into individual capacitors.

The cutting of the anode rod 1 by the punching press machine is performed as follows, for example. First, the anode rod 1 connected to the horizontal bar 3 is placed on a support 25 made of cemented carbide or the like, and a stripper 26 made of cemented carbide or the like is connected thereto from above the anode rod 1. The anode rod 1 is pressed down on the support base 25 by moving it downward with a pneumatic cylinder or the like. Next, as shown in the cross-sectional view of the main part of FIG.
7 is moved down along the stripper 26 to make a notch by pressing the blade edge 27a against the peripheral surface of the pressed anode rod 1 to apply shear stress, and further move the cutting blade 27 downward. After cutting the anode rod 1,
The downward movement of the cutting blade 27 is stopped. At this time, the cutting blade 27
The blade surface 27b of is located at a position facing the cut surface of the anode rod 1. Then, the cutting blade 27 is raised and returned to the original position. By repeating such an operation, each capacitor element is sequentially separated from the horizontal bar 3. When cutting the anode rod 1, the edge portion 25a of the support base 25 is
It plays the role of a facing blade with respect to the cutting edge 27a of the cutting blade 27.

[0005]

However, when the anode rod 1 is cut by the conventional method described above, shear deformation of the anode rod 1 is caused by the clearance between the stripper 26 and the blade surface 27b of the cutting blade 27. Due to the accompanying bending deformation, burrs in the cutting direction of the cutting blade 27 are generated on the cut surface of the anode rod 1 (particularly on the lower side of the cut surface), so that the anode rod 1 is formed on this, as shown in FIG. With the burr and the lead terminal 22a in contact with each other, the lead terminal 2
Since it will be placed on 2a, the two electrode rods 23
When sandwiching and welding the anode rod 1 and the lead terminal 22a with each other, it is easy to cause welding failure such as unwelding due to changes in welding conditions such as the contact area between the anode rod 1 and the lead terminal 22a is not constant. There was a problem.

Further, as shown in FIG. 12, the lead terminal 2
2a is easily welded in a state where the anode rod 1 is inclined (solid line in the figure), and when connecting the chip piece 2 and the lead terminal 22b with a metal wire, the bonding condition of the metal wire to the chip piece 2 is Therefore, the resin mold portion 24 can be increased in size in order to reliably cover the chip piece 2 in anticipation of the positional deviation of the chip piece 2 on the lead terminal 22a, in addition to the possibility of welding failure of the metal wire. It becomes necessary and the density of the chip pieces 2 becomes smaller accordingly,
In recent years, with the demand for smaller electronic components,
There is a problem that it is very difficult to increase the capacity of the capacitor.

In order to solve this, as shown in FIG. 13 (a), the anode terminal is cut by bringing the blade edge into contact with the blade edge, and the shape of the burr generated on the cut surface of the anode terminal is shown in FIG. Although the idea of making it as shown in (b) has been proposed, in this case, when the cutting edges come into contact with each other, the cutting edges are worn or chipped, so that the cutting blades should be frequently replaced. Was required, which was not suitable for practical use.

Further, as shown in FIG. 14, there has been proposed a method of cutting the cutting blade from the lower side to the upper side toward the anode terminal. In this case, the driving component of the cutting blade is placed at the mounting position of the capacitor element. Since it has to be arranged further downward, maintainability is greatly deteriorated when repairing or replacing parts. The present invention has been devised under the circumstances as described above, and it is possible to weld a chip piece in a state where it is reliably positioned on a lead frame, and to realize a large-capacity solid electrolytic capacitor. It aims at providing the manufacturing method of.

[0009]

In order to solve the above problems, the present invention connects a plurality of capacitor elements each having a chip piece and an anode terminal protruding from the chip piece, and sandwiches the anode terminal. After stopping the descending movement of the cutting blade at a position where the blade surface of the cutting blade is separated by cutting the anode terminal by moving the cutting blade downward in the state, the blade surface of the cutting blade is By raising the cutting blade so as to follow the cut surface of the anode terminal, a separation step of separating each capacitor element, and holding and conveying the chip piece of the capacitor element separated in the separation step, A carrying step of bringing the tip portion of the anode terminal into contact with the lead frame, and fixing the capacitor element carried in the carrying step at the contact portion between the anode terminal and the lead frame. Ri, there is provided a method of manufacturing a solid electrolytic capacitor and a connection step of connecting to the lead frame.

The present invention is a device for cutting the anode terminal used in the separation step in the method for manufacturing a solid electrolytic capacitor, comprising a holding member for holding the anode terminal, and the anode terminal held by the holding member. With respect to the cutting blade drive unit for moving the cutting blade up and down, the cutting blade, a cutting unit that moves downward by the cutting blade drive unit to cut the anode terminal, and after cutting the anode terminal The present invention provides a solid electrolytic capacitor manufacturing apparatus characterized by having the cut portion and a clearance portion which is separated from the cut portion.

[0011]

According to the method of manufacturing a solid electrolytic capacitor of the present invention, the anode terminal of each capacitor element is cut in the separating step as follows by using the cutting device of the present invention. That is, while the anode terminal is sandwiched by the sandwiching member, the cutting blade is moved downward by the cutting blade drive unit, and shear deformation is generated in the cutting direction of the cutting blade by applying shear stress to the anode terminal. Cut and cut so that the cut piece cut by the cutting blade at the lower end of the cut of the anode terminal is torn off from the anode terminal. At this time, at the cutting lower end of the anode terminal, a reaction force against the shear stress, that is, a force acts in a direction that does not divide the cut piece due to the shear strength of the anode terminal, and shear deformation (the boundary portion between the anode terminal and the cut piece is When the cutting piece is cut, a burr is generated in the cutting direction of the cutting blade (direction in which the cutting piece is cut) at the boundary with the cutting piece. Furthermore, the cutting blade is moved down to a position where the blade surface is separated from the anode terminal.At this time, since the burr generated above is also separated from the blade surface of the cutting blade, shear stress is generated by the relief portion of the cutting blade. The so-called springback, which tries to return to the original shape when removed, changes its generation direction slightly to the length direction of the anode terminal. After that, since the cutting blade is moved upward so that the blade surface follows the cutting surface of the anode terminal, the burr comes into contact with the blade surface of the cutting blade and corrects its generation direction to the rising direction of the cutting blade. Can be changed. In this way, the direction in which burrs are generated on the cut surface of the anode terminal is changed to the rising direction of the cutting blade, so after separating each capacitor element, the chip piece is held and transferred in the transfer step, When the tip of the capacitor is brought into contact with the lead frame, for example, the upper surface of the chip piece of the capacitor element may be held and moved on the lead frame without being inverted or rotated at a desired angle. The mounting state of the anode terminal on the lead frame is always stable without the burr coming into contact with the lead frame. Therefore, in the connection step, the contact portion between the anode terminal and the lead frame,
For example, when fixing by arc welding, the welding conditions such as the contact area between the anode terminal and the lead frame are almost constant,
A stable and stable connection can be obtained. Further, it is easy to weld the upper surface of the anode terminal in a state parallel to the lead frame surface. For example, even when the chip piece and the lead frame are connected by a metal wire, the bonding condition of the metal wire to the chip piece is substantially constant. In addition to preventing defective welding of the metal wire, the size of the resin mold portion covering the chip piece can be minimized, so that the capacitor can be made smaller.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 to 9, but the present invention is not limited to this. First, the element part of the solid electrolytic capacitor is manufactured in the same manner as that shown in FIG. That is, first, in this capacitor element, particles of valve-acting metal such as tantalum or niobium are molded into a porous chip piece 2 in a state where an anode rod 1 (anode terminal) made of metal such as tantalum or niobium is projected. After firing, a plurality of the chip pieces 2 are attached by fixing the anode rods 1 in the longitudinal direction of a long horizontal bar 3 made of stainless steel by welding or the like at appropriate pitch intervals. It is manufactured by sequentially forming a tantalum pentoxide layer, a manganese dioxide layer and a silver layer on the surface of the chip piece 2.

Next, the capacitor element is separated from the horizontal bar 3 by cutting the anode rod 1 by a molding press as shown below. 2 and 3 are a perspective view and a cross-sectional view of a main part showing a cutting device for the anode rod 1 in each capacitor element. This cutting device includes a rectangular parallelepiped support base 4 (holding member) made of cemented carbide for supporting the peripheral surface of the anode rod 1 in the capacitor element, and an anode on the support base 4 that moves up and down with respect to the support base 4. It comprises a rectangular parallelepiped stripper 5 (holding member) made of cemented carbide for holding and sandwiching the rod 1, and a cutting blade 6 made of cemented carbide that moves up and down along the stripper 5 with respect to the support 4.

The cutting blade 6 has a U-shaped cross section in a cross section in which a concave portion (relief part) is provided in the central portion of the side surface of the rectangular parallelepiped, and the lower edge thereof has a cutting edge with an acute angle in cross section. 6a (cutting portion), and is arranged so as to slide along the stripper 5 from the blade tip 6a to the blade surface 6b (cutting portion). Further, a pneumatic cylinder 7 (cutting blade drive unit) for moving the cutting blade 6 up and down is connected to the upper surface 6c of the cutting blade 6,
Two cylindrical column-shaped pins 8 made of iron having a flange 8a on the top are inserted so as to be slidable in the through holes formed on the upper surface 6c, and the lower ends of these pins 8 are attached to the stripper 5. By inserting into a groove hole formed in the upper surface 5a and screwing a bolt (not shown) or the like from the side surface thereof to press and fix it,
It works together with the stripper 5. Furthermore, since the compression springs 9 are inserted into the respective pins 8 between the upper surface 5a of the stripper 5 and the upper surface 6d of the recess of the cutting blade 6, the cutting blade 6 can be installed after the stripper 5 stops. Can also be moved down along the stripper 5. The cutting blade 6 has a lower surface 6e in the recess.
Until the blade is located below the upper surface 4a of the support base 4,
b can move downward along the side surface 4b of the support base 4, and the respective clearances between the stripper 5 and the side surface 4b of the support base 4 and the blade surface 6b of the cutting blade 6 are arranged substantially constant. There is.

The anode rod 1 is cut in the following manner by using the cutting device having the above structure. First, after placing the outermost capacitor element among the capacitor elements connected to the horizontal bar 3 on the support base 4 so that the peripheral surface of the anode rod 1 abuts on the upper surface 4a of the support base 4, the cylinder element is placed on the cylinder 4. 7 is operated to lower the stripper 5, and the anode rod 1 is pressed so as to be sandwiched between the stripper 5 and the upper surface 4a of the support 4, and then the stripper 5 is pushed toward the sandwiched anode rod 1. By further moving the cutting blade 6 interlocked with the blade edge 6a to press the peripheral surface of the anode rod 1,
A cut is made while applying a shearing stress to the anode rod 1 to cause shear deformation occurring in the cutting direction of the cutting blade 6 (see FIG. 4A).

Further, the cutting blade 6 is moved downward to deepen the cutting into the anode rod 1, and the cut piece 1a cut by the cutting blade 6 at the lower cutting end of the anode rod 1 is torn off from the anode rod 1. To divide. At this time, at the cutting lower end portion of the anode rod 1, a reaction force against the shear stress, that is, a shearing strength of the anode rod 1 acts in a direction in which the cutting piece 1a is not divided, resulting in shear deformation (anode rod 1 and cutting piece 1a). Deforms to a state where the boundary between and is fully extended)
And finally when the cut piece 1a is cut,
Burrs are generated in the cutting direction of the cutting blade 6 (the direction in which the cutting piece 1a is divided) at the boundary with the cutting piece 1a (FIG. 4B).
reference).

Then, the cutting blade 6 is moved down to a position where the blade surface 6b thereof is separated from the anode rod 1 (the lower surface 6e of the concave portion of the cutting blade 6 is located below the upper surface of the support 4).
At this time, the burr generated above is also the blade surface 6 of the cutting blade 6.
Since it is separated from b, the generation direction is slightly changed to the longitudinal direction of the anode rod 1 by so-called spring back, which tries to return to the original shape when the shear stress is removed.
After that, the cutting blade 6 is moved upward so that the cutting surface 6b follows the cutting surface of the anode rod 1, so that the burr first comes into contact with the edge portion 6f of the cutting surface 6b of the cutting blade 6 to cut the cutting blade 6. 6 is pressed in the ascending direction, and the generation direction thereof can be corrected to the ascending direction (see FIG. 4C, separation step).

As shown in FIG. 5, the capacitor elements separated as described above are made to face each other by extending and holding the upper surface of the chip piece 2 by a suction pad 10 and extending to a lead frame 11 made of copper. A pair of lead terminals 11
The anode rod 1 is moved while being positioned on one of the lead terminals 11a and 11b so that the peripheral surface of the tip portion of the anode rod 1 contacts the lead terminal 11a. At this time, since the burr generated on the cut surface of the anode rod 1 is changed to the ascending direction of the cutting blade 6, for example, the upper surface of the chip piece 2 is held and inverted or rotated at a desired angle. Even if the anode rod 1 is moved onto the lead terminal 11a without being pushed, the mounting state of the anode rod 1 on the lead terminal 11a is always stable without the burr coming into contact with the lead terminal 11a.

The suction surface of the suction pad 10 can follow the upper surface of the chip piece 2 in order to securely suck and hold the upper surface of the chip piece 2. The suction pad 10 is operated by a link mechanism or the like using a cam that is driven by a motor (not shown) (moving step). Further, as shown in FIG. 6, in a state where the chip piece 2 is sucked and held by the suction pad 10, the anode rod 1 and the lead terminal 1 are
1a and 2a are pressed so as to be sandwiched by the two electrode rods 12 from above and below, and the electrode rods 12 are energized to weld the anode rods 1 to the lead terminals 11a, thereby fixing and connecting them. At this time, as described above, the mounting state of the anode rod 1 on the lead terminal 11a is always stable without the burr coming into contact with the lead terminal 11a. The welding conditions such as the contact area with and the like become substantially constant, and a stable and stable connection state can be obtained.

Further, the upper surface of the anode rod 1 is connected to the lead terminal 11a.
Even if the chip piece 2 and the lead terminal 11b are partially connected to each other by the metal wire 14 coated with the silicone resin 13 as shown in FIG. The bonding conditions of the chip piece 2 to the chip piece 2 are substantially constant, the welding failure of the metal wire 14 can be prevented, and the resin mold portion 15 that covers the chip piece 2
Since the size of the capacitor can be minimized, the capacitor can be made smaller (connection process).

After molding the resin mold portion 15 in this manner, the lead frame 11 is punched and bent by a press molding machine or the like to separate the lead frame 11 into individual capacitor parts. In the present embodiment, the cutting blade 6 has a rectangular parallelepiped shape in which a recess is provided in the center of the side surface of the rectangular parallelepiped. However, the invention is not limited to this, and the cutting blade 6 is lifted after descending. It is only necessary to form a relief portion for the anode rod 1 having an edge portion 6f or the like that comes into contact with the burr to change the burr forming direction of the cutting surface of the cutting blade 6 to the ascending direction when the cutting blade 6 is moved. Through hole 6g as shown in Fig. 8
May be provided, or a groove which does not penetrate may be formed. The shape of the through hole 6g and the groove is not limited to this.

The side shape of the cutting blade 6 may be uneven as shown in FIG. Further, in the present embodiment, the cutting blade 6 and the stripper 5 are linked, but they may be operated independently. In addition, in the present embodiment, the anode rods 1 in each capacitor element connected to the horizontal bar 3 are cut one by one, but the present invention is not limited to this, and each anode bar 1 connected to the horizontal bar 3 is cut. After cutting the anode rod 1 in the capacitor element at a time, each capacitor element is attracted and held at one time by using the adsorption pad 10 which can be independently turned on / off by corresponding to each capacitor element and sequentially on the lead terminals. It is also possible to move to.

Further, in the separation step in this embodiment, the cutting blade 27 is moved up and down with respect to the anode rod 1, but the cutting blade 27 may be individually provided on the upper and lower sides with the anode rod 1 interposed therebetween.

[Brief description of drawings]

FIG. 1 is a main part perspective view showing a capacitor element in a solid electrolytic capacitor.

FIG. 2 is a perspective view of essential parts showing an anode rod cutting device for carrying out the method for producing a solid electrolytic capacitor of the present invention.

FIG. 3 is a side view of essential parts showing a device for cutting an anode rod for carrying out the method for producing a solid electrolytic capacitor of the present invention.

FIG. 4 is an explanatory diagram illustrating a separation step in the method for manufacturing a solid electrolytic capacitor of the present invention.

FIG. 5 is an explanatory diagram illustrating a moving step in the method for manufacturing a solid electrolytic capacitor of the present invention.

FIG. 6 is an explanatory diagram illustrating a connecting step in the method for manufacturing a solid electrolytic capacitor of the present invention.

FIG. 7 is a perspective view of a main part showing a solid electrolytic capacitor manufactured by using the method for manufacturing a solid electrolytic capacitor of the present invention.

FIG. 8 is a perspective view of essential parts showing a modified example of the apparatus for cutting an anode rod for carrying out the method for producing a solid electrolytic capacitor of the present invention.

FIG. 9 is a side view of essential parts showing a modified example of the device for cutting an anode rod for carrying out the method for producing a solid electrolytic capacitor of the present invention.

FIG. 10 is an explanatory diagram illustrating a method for cutting an anode rod in a conventional method for manufacturing a solid electrolytic capacitor.

FIG. 11 is an explanatory diagram illustrating a contact state between an anode rod and a lead terminal when they are connected to each other in a conventional method for manufacturing a solid electrolytic capacitor.

FIG. 12 is an explanatory diagram illustrating a contact state between an anode rod and a lead terminal when they are connected to each other in a conventional method for manufacturing a solid electrolytic capacitor.

FIG. 13 is an explanatory diagram illustrating the shape of the tip of the anode rod when the anode rod is cut in the conventional method for manufacturing a solid electrolytic capacitor.

[Explanation of symbols]

 1 Anode bar 2 Chip piece 3 Horizontal bar 4 Support stand 5 Stripper 6 Cutting blade 7 Cylinder 8 Pin 9 Compression spring 10 Adsorption pad 11 Lead frame 12 Electrode bar 13 Silicone resin 14 Metal wire 15 Resin mold part

Claims (2)

[Claims] 1. A plurality of capacitor elements each having a chip piece and an anode terminal protruding from the chip piece are connected to each other, and a cutting blade is moved down while the anode terminal is sandwiched to cut the anode terminal. After stopping the lowering movement of the cutting blade at a position where the blade surface of the cutting blade separates from the anode terminal, raise the cutting blade so that the blade surface of the cutting blade follows the cutting surface of the anode terminal. A step of separating each capacitor element by moving the capacitor element, and a step of holding and carrying the chip piece of the capacitor element separated in the separating step, and bringing the tip of the anode terminal into contact with the lead frame. And a connection step of connecting the capacitor element transferred in the transfer step to the lead frame by fixing the contact portion between the anode terminal and the lead frame. Manufacturing method of body electrolytic capacitor. 2. A cutting device for the anode terminal used in the separation step in the method for manufacturing a solid electrolytic capacitor according to claim 1, wherein the holding member holds the anode terminal, and the holding member holds the holding member. A cutting blade drive unit that moves the cutting blade up and down with respect to the anode terminal, the cutting blade is a cutting unit that moves downward by the cutting blade drive unit to cut the anode terminal, and cuts the anode terminal. The manufacturing apparatus for a solid electrolytic capacitor, comprising: