JP2018061015A - Manufacturing method of lead wire terminal, chip type electrolytic capacitor and semifinished product of lead wire terminal - Google Patents

Abstract

A solder wettability of a lead portion of a lead wire terminal for a chip-type electrolytic capacitor is prevented from being locally reduced, and generation of metal powder is suppressed. A method of manufacturing a lead wire terminal 4 having a strip-like lead portion 41 and a terminal portion 42 provided at one end thereof and attached to the capacitor element 3 of the chip-type electrolytic capacitor 1 via the terminal portion. And a step of preparing a metal wire 411 having a polygonal cross section provided with a coating layer 412 having good solder wettability on the outer periphery, and a step of forming the lead portion 41 by pressing the metal wire 411. . [Selection] Figure 4

Description

  The present invention relates to a method of manufacturing a lead wire terminal for a chip type electrolytic capacitor, a chip type electrolytic capacitor, and a semifinished product of the lead wire terminal.

  In general, a lead wire terminal for a chip-type electrolytic capacitor has a strip-shaped lead portion soldered to a circuit board and a terminal portion provided at one end thereof, and the chip-type electrolytic capacitor via the terminal portion. It is attached to the capacitor element. The lead portion is formed in a band shape by pressing a metal wire having a circular cross section in the radial direction (Patent Document 1). In addition, the lead portion should be formed of a metal wire having a coating layer (for example, a tin plating layer) with good solder wettability on the outer periphery in order to ensure the reliability of the soldering strength with the circuit board. There is.

JP-A-11-26327

  Conventionally, since the metal wire forming the lead portion has a circular cross section, when the metal wire is pressed, the thickness of the coating layer provided on the outer periphery is locally reduced, and solder wettability may be impaired.

  FIG. 7 is an explanatory view of a conventional pressing process of the lead portion. As shown in FIG. 7A, the metal wire 511 forming the lead portion has a circular cross section, and a coating layer 512 is provided on the outer periphery. As shown in FIG. 7B, the metal wire 511 is sandwiched between the first press die 110 and the second press die 120 to form a strip-shaped lead portion. The metal wire 511 is deformed to have an elliptical cross section when being pinched. At this time, since the covering layer 512 is relatively soft, its thickness is the thinnest at the top and bottom of the central portion of the metal wire 511 and faces both sides. It becomes thicker gradually.

  As described above, when the thickness of the covering layer 512 is locally reduced, the solder wettability is greatly reduced at that portion, and the reliability of the soldering strength may be impaired. In addition, since the coating layer 512 is thick on both sides, there is also a problem that a large amount of metal powder is generated on both sides of the metal wire 511, which easily causes short circuit of the circuit board and deterioration of the capacitor characteristics.

  The present invention was devised in view of the above circumstances, and its purpose is to suppress the local decrease in solder wettability of the lead portion of the lead wire terminal for a chip-type electrolytic capacitor and to prevent the generation of metal powder. It is to suppress.

  In order to achieve the above object, the first invention has a strip-shaped lead portion 41 and a terminal portion 42 provided at one end thereof, and the capacitor element 3 of the chip-type electrolytic capacitor 1 through the terminal portion 42. A method of manufacturing a lead wire terminal 4 attached to a metal wire 411, a step of preparing a metal wire 411 having a polygonal cross section provided with a coating layer 412 having good solder wettability on the outer periphery, and pressing the metal wire 411 Forming the lead portion 41.

  Moreover, 2nd invention is a chip-type electrolytic capacitor provided with the lead wire terminal 4 manufactured by 1st invention.

  In addition, the third invention has a strip-shaped lead portion 41 and a terminal portion 42 provided at one end thereof, and is a lead wire terminal attached to the capacitor element 3 of the chip-type electrolytic capacitor 1 via the terminal portion 42. 4 having a metal wire 411 having a polygonal cross section provided with a coating layer 412 having good solder wettability on the outer periphery, and extending from the terminal portion 42, It can be plastically deformed into the shape of the lead portion 41 by press working.

  ADVANTAGE OF THE INVENTION According to this invention, it can suppress that the solder wettability of the lead part of the lead wire terminal for chip type electrolytic capacitors falls locally, and can suppress generation | occurrence | production of metal powder.

It is a perspective view of the chip type electrolytic capacitor provided with the lead wire terminal by the present invention. It is a longitudinal cross-sectional view of the chip type electrolytic capacitor of FIG. It is a perspective view of the semifinished product of the lead wire terminal by this invention. It is explanatory drawing of 1st Embodiment of the lead wire terminal manufacturing method by this invention. It is explanatory drawing of 2nd Embodiment of the lead wire terminal manufacturing method by this invention. It is explanatory drawing of the lead wire terminal manufacturing method of a comparative example. It is explanatory drawing of the conventional lead wire terminal manufacturing method.

Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
As shown in FIGS. 1 and 2, the chip electrolytic capacitor 1 of the present embodiment is derived from the bottomed cylindrical container 2, the capacitor element 3 accommodated in the container 2, and the capacitor element 3. A pair of lead wire terminals 4, a sealing member 5 for sealing the opening of the container 2, and a seat plate 6 provided on the opening end side of the container 2. The container 2 is made of a metal thin plate, and the opening end is bent inward to fix and support the sealing member 5.

  The lead wire terminal 4 has a strip-like lead portion 41 bent in an L shape, and a terminal portion 42 is provided at one end thereof. The lead portion 41 is formed by pressing a metal wire having a square cross section into a strip shape. In the present embodiment, the metal wire is formed by cutting a long CP wire (copper-coated steel wire).

  As shown in FIG. 3, a terminal part 42 is provided at one end of a metal wire 411 to produce a semifinished product 4 ′ of a lead wire terminal. After the capacitor element 3 is assembled in the container 2, the metal wire 411 is pressed into a strip shape to form the lead wire terminal 4.

  A coating layer 412 (see FIG. 4) made of tin plating is provided on the outer periphery of the metal wire 411 in order to improve solder wettability. The terminal portion 42 is formed by pressing a rod-shaped member made of aluminum or the like, and has a flat portion 421 connected to the capacitor element 3 at one end. One end of a metal wire 411 is connected to the other end of the terminal portion 42 by welding or the like, and the metal wire 411 extends from the terminal portion 42.

  The sealing member 5 is made of rubber or the like and has a pair of through holes 51 through which the terminal portions 42 are inserted. The seat plate 6 is formed of an insulating material and is fixed to the opening end of the container 2 by adhesion or the like.

  The seat plate 6 includes a pair of through holes 61 through which the lead portions 41 are inserted, and a pair of grooves 62 that communicate with the through holes 61. The pair of lead portions 41 are inserted into the through holes 61, then bent in directions away from each other, and accommodated in the grooves 62.

Next, a method for manufacturing the lead wire terminal 4 will be described.
The lead wire terminal 4 is manufactured by the following procedure. First, a long CP wire having a polygonal cross section provided with a coating layer 412 on the outer periphery is cut to prepare a metal wire 411 having a length corresponding to the lead portion 41. Next, the terminal part 42 is provided at one end of the metal wire 411. Then, the lead portion 41 is formed by pressing the metal wire 411.

  In the step of forming the lead portion 41, as shown in FIG. 4A, the metal wire 411 is sandwiched between the first press die 110 and the second press die 120 and shown in FIG. 4B. Plastic processing into a belt shape like this. In addition, after processing the metal wire 411 into a strip shape, both sides thereof may be cut.

  Since the metal wire 411 has a quadrangular cross section, the thickness of the coating layer 412 is not locally reduced on both the upper and lower surfaces during pressing, and the thickness is substantially uniform over the entire length in the width direction.

  Therefore, as compared with the metal wire 511 having a circular cross section shown in FIG. 7, variation in the thickness of the coating layer 412 after being processed into a strip shape is reduced, so that it is possible to suppress a local decrease in solder wettability. it can. Thereby, the reliability of the soldering strength of the lead part 41 with respect to a circuit board improves.

  Further, since the variation in the thickness of the coating layer 412 is reduced, the thickness of the coating layer 412 can be suppressed from increasing on both sides, and metal powder is less likely to be generated. The decrease can be suppressed.

Next, a second embodiment of the present invention will be described.
As shown in FIG. 5A, in this embodiment, a plurality of groove-shaped recesses 130 are provided on the press surface 111 of the first press die 110 and the press surface 121 of the second press die 120. Yes. These recesses 130 are provided in parallel so as to extend in the axial direction of the metal wire 411 (direction orthogonal to the paper surface of FIG. 5), and the press surfaces 111 and 121 have a cross-sectional waveform.

  When the metal wire 411 is sandwiched between the first press die 110 and the second press die 120 by providing such a plurality of recesses 130, as shown in FIG. 412 is deformed into a cross-sectional waveform along the plurality of recesses 130, and a plurality of protrusions 412b extending in the axial direction of the metal wire 411 are formed, so that the residue 412a hardly protrudes on both sides of the metal wire 411.

  On the other hand, as shown in FIG. 6, when a plurality of groove-like recesses 130 are not provided on the press surface 111 of the first press die 110 and the press surface 121 of the second press die 120, FIG. Compared to the case, the residue 412a tends to protrude on both sides of the metal wire 411, so that the metal powder is easily spilled off.

  By providing the first press die 110 and the second press die 120 with the recess 130 as shown in FIG. 5, it is difficult for metal powder to spill out, thereby further suppressing the short circuit of the circuit board and the deterioration of the capacitor characteristics. Can do.

  The present invention is not limited to the above embodiments.

  For example, the cross-sectional shape of the metal wire may be a polygon other than a rectangle.

  The metal wire may be formed of a material other than CP wire.

  Further, instead of tin plating, a coating layer made of another material having good solder wettability may be provided on the outer periphery of the metal wire.

  The step of forming the lead portion by pressing the metal wire may be performed before the terminal portion is attached to the electrode foil of the capacitor element. In this case, the metal powder generated during the pressing process of the lead part can be attached to the electrode foil after sufficiently removing the metal powder from the lead wire terminal, so that the metal powder hardly adheres to the finished chip-type electrolytic capacitor. Therefore, it is possible to further suppress the short circuit of the circuit board, the deterioration of the capacitor performance, and the like. In addition, such a manufacturing method can acquire the same effect, when it applies when pressing metal wires other than a polygon in cross-sectional shape.

  Further, the shape of the recesses provided on the press surface of the first press die and the press surface of the second press die may be other than the groove shape, and the number of recesses may be singular.

  Moreover, you may provide a recessed part only in any one of a 1st press die and a 2nd press die. Even when a metal wire having a cross-sectional shape other than a polygon is pressed, by providing a recess in at least one of the press surface of the first press die and the press surface of the second press die, the same effect ( It is difficult for the residue to protrude from both sides of the metal wire, and metal powder is less likely to be generated.

DESCRIPTION OF SYMBOLS 1 Chip type electrolytic capacitor 3 Capacitor element 4 Lead wire terminal 4 'Semifinished product 41 of lead wire terminal 41 Lead part 42 Terminal part 110 1st press die 111 Press surface 120 2nd press die 121 Press surface 411 Metal wire material 412 Covering layer

Claims (7)

It has a strip-shaped lead part (41) and a terminal part (42) provided at one end thereof, and is attached to the capacitor element (3) of the chip-type electrolytic capacitor (1) via the terminal part (42). A method for manufacturing a lead wire terminal (4), comprising:
A step of preparing a metal wire (411) having a polygonal cross section provided with a coating layer (412) having good solder wettability on the outer periphery;
Forming the lead part (41) by pressing the metal wire (411);
Of manufacturing a lead wire terminal.   The method of manufacturing a lead wire terminal according to claim 1, wherein the step of forming the lead portion (41) is performed before the terminal portion (42) is attached to the capacitor element (3).   In the step of forming the lead portion (41), the metal wire (411) is sandwiched between a first press die (110) and a second press die (120), and the first press die The lead wire terminal according to claim 1 or 2, wherein a recess (130) is provided on at least one of the press surface (111) of (110) and the press surface (121) of the second press die (120). Production method.   The method for manufacturing a lead wire terminal according to claim 3, wherein the recess (130) has a groove shape extending in an axial direction of the metal wire (411).   The manufacturing method of the lead wire terminal of Claim 4 with which the said several recessed part (130) is provided in parallel.   A chip type electrolytic capacitor provided with the lead wire terminal (4) manufactured by the manufacturing method in any one of Claims 1 thru | or 5. It has a strip-shaped lead part (41) and a terminal part (42) provided at one end thereof, and is attached to the capacitor element (3) of the chip-type electrolytic capacitor (1) via the terminal part (42). Semi-finished product (4 ') of lead wire terminal (4),
A metal wire (411) having a polygonal cross section provided with a coating layer (412) having good solder wettability on the outer periphery, extending from the terminal portion (42);
The metal wire (411) is a semi-finished lead wire terminal that can be plastically deformed into the shape of the lead portion (41) by press working.

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