JP2005302853A - Sheet metal wiring - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide sheet metal wiring easy in soldering by preventing a solder flow out from a section to be mounted with a circuit component at the time of mounting the circuit component. <P>SOLUTION: A bus bar 2 is used as sheet metal wiring, and provided on the printed circuit board 1. The lead end 4a of a passive circuit component 3 is laid on a section 2a to be mounted with the circuit component of the bus bar 2, and mounted by being soldered with solder 5. A solder outflow suppression part 10 is formed on the surface of the bus bar 2, and formed so that the boundary of a bus bar 2 body and the section 2a may be recessed in a groove shape. During the soldering process of a passive circuit element 3, the enlargement of the wet of the melting solder 5 is prevented by the solder flow suppression part 10, so that the wet cannot get across the boundary of the section 2a. Namely, the melting solder 5 remains on the surface of the section 2a, without falling down by being wet from a corner 11 which is the boundary of the section 2a. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to sheet metal wiring such as a bus bar on which circuit components such as a power supply device are mounted and a large current flows.

  Usually, the conductive pattern of a printed circuit board that is generally widely used as a circuit board is formed by etching or printing a thin-film copper foil. For example, in the case of a circuit configuration that allows a large current to flow locally, such as a power supply device, there is a risk of disconnection in a conductive pattern formed of such a thin copper foil, so the magnitude of the current that flows through the conductive pattern is naturally limited. . Therefore, sheet metal wiring such as a bus bar disclosed in Patent Document 1 is generally used for a circuit through which a large current flows. A bus bar made of a conductive metal material has a considerable thickness as compared with a conductive pattern formed of a copper foil, so there is no possibility of disconnection even when a large current is passed. Note that the bus bar is partially used for a circuit portion that flows a large current, such as a power supply device, and thus needs to be mounted on a circuit board such as a printed board.

FIG. 4 is a partial perspective view of a sheet metal wiring in a conventional example. In the figure, reference numeral 1 denotes a circuit board such as a printed circuit board on which electronic components are mounted, and a bus bar 2 as a sheet metal wiring is provided on the circuit board 1. The bus bar 2 is formed by plating the surface of a metal flat plate having excellent conductivity such as copper. The circuit board 1 is provided with a solder solid pad (not shown) for the bus bar 2 and is soldered. In this way, the bus bar 2 is fixed to the circuit board 1 and the circuit portion of the circuit board 1 and the bus bar 2 are electrically connected. Reference numeral 2 a denotes a mounted portion of the bus bar 2 on which the circuit component 3 is mounted. The lead end portion 4 a of the circuit component 3 is placed on the mounted portion 2 a and soldered with the solder 5. The lead 4 of the circuit component 3 is bent so that the lead end 4a is substantially parallel to the surface of the mounted portion 2a. That is, in order to surface-mount the circuit component 3 on the flat-plate-like mounted portion 2a, the lead 4 has an SMD shape that is bent in a step shape, and the lead end portion 4a and the mounted portion of the bus bar 2 2a is directly soldered and connected. Therefore, on the circuit board 1, the bus bar 2 and the circuit component 3 are mounted in a stacked state.
JP 2001-309524 A

  However, in the conventional sheet metal wiring as described above, when the circuit component 3 is mounted on the mounted portion 2a extending from one side of the bus bar main body 2b by soldering, the mounted portion 2a of the bus bar 2 is in another part. As in the case of the bus bar main body 2b, it has a flat plate shape, so that there is a problem that the molten solder 5 (molten solder 5) flows out from the mounted portion 2a and spreads to the bus bar main body 2b. Therefore, an appropriate amount of solder 5 cannot be obtained at the lead end portion 4a of the circuit component 3 placed on the bus bar 2, and a good fillet may not be formed on the side surface of the lead end portion 4a. In addition, such a shortage of solder amount hinders reliable electrical connection, which in turn causes a product failure. Therefore, a process for correcting the soldering of the circuit component 3 is required separately, which leads to an increase in the number of man-hours, correction workers, work space, and the like.

  SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a sheet metal wiring that prevents solder from flowing out from a mounted portion during circuit component mounting and facilitates soldering.

  In the sheet metal wiring according to claim 1 of the present invention, in the sheet metal wiring formed by mounting a circuit component that can be soldered on the surface, a solder outflow prevention portion is formed at a boundary portion of the mounted portion on which the circuit component is mounted. It is configured as follows.

  In this way, when soldering the circuit component to the mounted part of the sheet metal wiring, the solder outflow prevention part uses the surface tension of the molten solder to prevent the molten solder from flowing out from the mounted part. Is possible. Accordingly, an appropriate amount of solder can be attached to, for example, the lead end portion of the circuit component, and a good fillet can be easily formed on the side surface of the lead end portion of the circuit component.

  Since the present invention is as described above, the following effects can be obtained.

  According to the sheet metal wiring of the first aspect of the present invention, it is not necessary to correct the soldering of the circuit component mounted on the mounted portion, and it is possible to reduce the man-hours, the correction operator, and the work space.

  Hereinafter, preferred embodiments of sheet metal wiring according to the present invention will be described together with a manufacturing method thereof with reference to the accompanying drawings. In the embodiment, the same parts as those in the conventional example are denoted by the same reference numerals, and the description of the common parts will be omitted as much as possible.

  1 and 2 show sheet metal wiring in the present embodiment. In the figure, reference numeral 1 denotes a circuit board such as a printed board on which electronic components are mounted. A bus bar 2 as a sheet metal wiring is provided on the printed board 1. The bus bar 2 is formed by plating the surface of a metal flat plate having excellent conductivity such as copper. The circuit board 1 is provided with a solder solid pad (not shown) for the bus bar 2 and is soldered. In this way, the bus bar 2 is fixed to the circuit board 1 and the circuit portion of the circuit board 1 and the bus bar 2 are electrically connected. Here, the bus bar 2 is configured by projecting a mounted portion 2a on which the circuit component 3 is mounted from one side of the flat-plate-shaped bus bar body 2b, and a lead end 4a which is a mounting portion of the circuit component 3 is mounted. The lead end 4 a and the mounted portion 2 a are connected to each other by the solder 5. The lead 4 of the circuit component 3 has an SMD shape bent in a step shape, and the lead end 4a and the mounted portion 2a of the bus bar 2 are directly soldered and connected. The above is the same configuration as the conventional example shown in FIG. The mounted portion 2a of the bus bar 2 refers to a portion of the bus bar 2 where the lead end portion 4a of the circuit component 3 is placed, and does not necessarily indicate the entire end portion of the bus bar 2.

  Reference numeral 10 denotes a solder outflow prevention portion provided on the surface of the bus bar 2, and is located at a boundary portion between the bus bar main body 2b and the mounted portion 2a, and known processing techniques such as embossing and cutting so as to be recessed in a groove shape. It is formed using. At this time, the corner portion 11 formed by the upper surface of the mounted portion 2a and the side wall of the solder outflow prevention portion 10 is preferably formed so as not to have an R shape or an obtuse angle shape. Further, the width and depth of the groove may be set appropriately according to the processing technique, but care must be taken because the direct current resistance increases as the cross-sectional area of the solder outflow prevention portion 10 decreases. Of course, a mold for forming the bus bar 2 and the solder outflow restraining portion 10 may be prepared, and the bus bar 2 and the solder outflow restraining portion 10 may be formed simultaneously.

  Next, the effect | action of the sheet metal wiring in a present Example is demonstrated.

  The circuit component 3 is placed on the mounted portion 2a of the bus bar 2 so that the upper surface of the mounted portion 2a and the bottom surface of the lead end portion 4a face each other, and is soldered through a soldering process such as manual work or reflow soldering. Attached. In the soldering process, the solid or paste solder is heated to the melting point (general solder is about 180 ° C.) to form the liquid molten solder 5, and the upper surface of the mounted portion 2 a and the lead end 4 a are molten solder. 5, the solder fillet is formed on the side surface of the lead end 4a. Then, it is solidified by natural cooling or the like to become the solder 5, and the surface of the mounted portion 2a and the lead end portion 4a are firmly connected.

  Hereinafter, the description will focus on the molten solder 5 and the bus bar 2 in the soldering process. Between the liquid molten solder 5 and the bus bar 2, an intermolecular force between the objects due to the molecules constituting each object acts as is well known. The intermolecular force between the objects acts between the surface of the molten solder 5 and the upper surface of the bus bar 2 (mounted portion 2a), and the molten solder 5 is pulled by the intermolecular force between the objects. The wetting gradually spreads on the mounted portion 2a of the bus bar 2. Thereafter, the wetting by the molten solder 5 reaches the boundary portion (corner portion 11) of the mounted portion 2a. At the boundary portion of the mounted portion 2a, the upper surface of the bus bar 2 falls greatly downward from the corner portion 11 of the mounted portion 2a, so that the space between the molten solder 5 surface and the upper surface of the bus bar 2 (mounted portion 2a) The intermolecular force between the acting objects is naturally reduced. In addition, since the liquid such as the molten solder 5 tends to be stabilized by being rounded by the surface tension (surface tension works toward the center of the liquid) as is well known, It stays on the upper surface of the mounted part 2a without falling off from the part 11. In this way, the expansion of wetting by the molten solder 5 is suppressed by the solder outflow suppression unit 10 provided on the bus bar 2, and does not exceed the boundary of the mounted portion 2a. However, if the amount of the solder 5 placed on the mounted portion 2a is too large, it will fall off, and it is necessary to adjust the amount of solder appropriately.

  FIG. 3 shows a modification of the sheet metal wiring in the present embodiment. The bus bar 2 is formed by bending so that the bus bar main body 2b and the mounted portion 2a are stepped. Other configurations are the same as those of the embodiment of FIGS. In this case, the solder outflow prevention portion 10 is a peripheral portion of the corner portion 11 located at a boundary portion between the bus bar 2 main body and the mounted portion 2a.

  As described above, in the present invention, in the bus bar 2 as the sheet metal wiring formed by mounting the circuit component 3 that can be connected by soldering, the solder outflow prevention portion 10 is provided at the boundary portion of the mounted portion 3a on which the circuit component 3 is mounted. Configured to form.

  In this way, when the circuit component 3 is soldered to the mounted portion 2 a of the bus bar 2, the solder outflow prevention unit 10 melts from the mounted portion 2 a of the bus bar 2 using the surface tension of the molten solder 5. It becomes possible to prevent the solder 5 from flowing out. Accordingly, an appropriate amount of solder can be obtained at the lead end portion 4a of the circuit component 3, and a good fillet can be easily formed on the side surface of the lead end portion 4a of the circuit component 3. Further, it is not necessary to correct the soldering of the circuit component 3 mounted on the mounted portion 2a, and it is possible to reduce man-hours, correction workers, and work space.

  In addition, this invention is not limited to the said Example, It can change in the range which does not deviate from the meaning of this invention. Here, the solder outflow prevention portion may be provided anywhere as long as it is a portion where it is desired to suppress the outflow of molten solder, and may be provided so as to surround the mounted portion of the sheet metal wiring. The solder outflow prevention part is not limited to the concave groove, but may be configured to block the outflow of the molten solder by a protruding wall, or by forming a wall by denting the mounted part of the sheet metal wiring itself. Also good.

It is a fragmentary perspective view of the sheet metal wiring in one example of the present invention. It is a principal part sectional drawing of sheet metal wiring same as the above. It is principal part sectional drawing which shows the modification of sheet metal wiring same as the above. It is a fragmentary perspective view of the sheet metal wiring in the prior art example of this invention.

Explanation of symbols

2 Bus bar (sheet metal wiring)
2a Mounted part 3 Circuit parts
10 Solder outflow prevention part

Claims (1)

A sheet metal wiring comprising a solderable and connectable circuit component mounted on a surface thereof, wherein a solder outflow suppressing portion is provided at a boundary portion of a mounted portion on which the circuit component is mounted.

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