JPS61186163A - Soldering instrument - Google Patents

Abstract

PURPOSE:To prevent the short circuit in soldering and to increase the products quality by making the carrier guide rail of printed wiring board in double construction for front and rear wheel, by providing a parabolic slope part on the outlet side rail of solder tank and by delaying the peel back point at the tip part of the substrate. CONSTITUTION:The guide rail of the carrier 14 of a printed wiring board 13 is made the double structure of the rail 10 for front wheel 15 and rail 11 for rear wheel 16 and the carrier 14 is made so as to dip with translation into a solder tank 12. In such case parabolic slant parts 19, 20 are provided respectively on the rail at solder outlet side. The peel back point which becomes in arc shape in the slant direction by the abrupt rise of the tip part of the carrier 12 and the surface tension caused immediately before the excess solder being released is delayed strenuously to prevent surely the solder short circuit and to better the quality of soldered products.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention relates to a method of soldering, for example, by immersing a printed wiring board in molten solder in a solder tank such as a static solder tank or a plane jet solder tank provided during transportation. Soldering is related to equipment.

[Technical Background of the Invention] In general, this type of soldering apparatus involves mounting a printed wiring board 2 supported by an inner frame 1 on a carrier 3, as shown in FIGS. front wheels 4 and rear wheels 5 of
are placed on a pair of first and second guide rails 7.8 laid down corresponding to the solder baths 6, respectively, and the carrier 3 is conveyed by a drive mechanism (not shown). When the carrier 3 reaches the solder bath 6, it is guided by the first and second guide rails 7 and 8 slanted parts 7a and 8a, and is lowered toward the molten solder surface to print. The wiring board 2 is immersed. Next, when the printed wiring board 2 is immersed in the carrier 3 for a predetermined period of time, the printed wiring board 2 is dissolved from the exit slopes 7b and 8b of the first and second guide rails 7.8. It is raised at an angle of 0 to 6 degrees with respect to the soldering surface, and electronic components such as ICs mounted on the printed wiring board 2 are soldered.

[Problems with Background Art] By the way, in the soldering device described above, each of the exit inclined portions 7b and 8b of the first and second guide rails 7.8 are formed in a straight line with a predetermined angle of inclination. Due to the configuration, when the printed wiring board 2 is removed from the melted solder 9 of the solder tank 6, if the front wheel 4 of the carrier 3 rides on the exit ramp 7b, the printed wiring board 2 will be removed as shown in FIG. The tip of 2 is melted solder 9
will be abruptly withdrawn from. As a result, in the printed wiring board 2, the so-called beer back point 9a, which forms an arc in the direction of inclination of the board due to the surface tension just before the adhering molten solder 9 separates, becomes extremely fast at its tip. Accordingly, a relationship arises in which the beer back point 9b becomes slower toward the rear end. According to this, the traveling direction of the printed wiring board 2 is A, and the moving direction of the beer back point 9a is 8. Assuming that the length of the printed wiring board 2 is C, the moving speed of the beer back point 9a is E, and the speed of the carrier 3 is E, the relationship between the printed wiring board 2 and the moving speed of the beer back point 9a is shown in FIG. As shown, beer back point 9
There are many solder short circuits (
Since a solder bridge (solder bridge) is generated, solder short circuits must be removed after the half-joint process is performed.The workability is very poor, and the soldering process has the drawbacks of poor quality.

In addition, when soldering the beer back point 9a,
If the printed wiring board 2 is bent so that the surface side of the printed wiring board 2 is slightly warped due to the heat of the melted solder 9, the beer back point 9a will be faster at the tip and the beer back point 9b will be slower at the rear end. This phenomenon is promoted.

Therefore, at the leading end and rear end of the printed wiring board 2,
Beer back points 9a and 9b that cause solder short circuits
There is a strong demand for a device that can be configured to reliably control the soldering process and perform high-quality soldering.

[Object of the Invention] This invention has been made in view of the above circumstances, and provides a soldering device that has a simple configuration, reliably prevents solder short circuits, and promotes improvement in solder quality. The purpose is to provide.

[Summary of the Invention] That is, the present invention provides a parabolic exit slope portion corresponding to at least the exit side of the solder tank on the guide rail on which the carrier is conveyed, and The intended purpose was achieved by configuring the beer back point to be as slow as possible.

“Embodiments of the Invention” An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a soldering apparatus according to the present invention, in which reference numerals 10 and 11 indicate a pair of first and second guide rails laid over a solder bath 12. These first. A front wheel 15 and a rear wheel 16 of a carrier 14 on which a printed circuit board 13 is attached using an unillustrated inner frame are movably mounted on the second guide rail 10.11.
is conveyed in the direction of arrow X by a drive mechanism (not shown). Each of the first and second guide rails 10.11 has, for example, a linear inlet slope 17.18 formed at one end corresponding to the inlet side of the solder bath 12, and the other end corresponding to the outlet side. Parabolic exit slopes 19 and 20 are formed at each end.

That is, the soldering apparatus starts when the carrier 14 on which the printed wiring board 13 is mounted is guided by the drive mechanism (not shown) to the first and second guide rails 10.11 and reaches the solder bath 12. , the printed wiring board 13 is lowered while being guided by each entrance ramp 17 , 18 , and the printed wiring board 13 is immersed in the molten solder 21 . Then, the printed wiring board 1
3 is immersed for a predetermined time, the carrier 14 is again moved between the first and second guide rails 1 by the drive mechanism.
It is guided by each exit ramp 19, 20 of 0.11 mm and is conveyed in the direction of arrow X. Then, the carrier 14 has its front wheels 15 and rear wheels 16 aligned with the first and second wheels, respectively.
The printed circuit board 13 is guided by the egress slope 19.20 of the guide rail 10.11 of the solder bath 12.
from the molten solder 21. At this time, as shown in FIG. 2, the printed wiring board 13 is separated from the molten solder 21 with its pulling angle gradually increasing along the exit slope 19.20, and the soldering is completed. be completed.

In this way, the soldering apparatus is connected to the solder tank 12 on the first and second guide rails 10 and 11 on which the carrier 14 is conveyed.
A parabolic exit slope 19, 20 is provided corresponding to at least the exit side of the printer, and the beer pack point 21a at the tip of the printed wiring board 13 is configured to be delayed as much as possible, so that solder short circuits are reliably prevented. Soldering effectively promotes quality improvement, and also improves work efficiency by eliminating the subsequent process of removing solder short circuits.

Further, in the above-mentioned embodiment, the present invention has
Although the description has been made for the case in which only 0 is configured in a parabolic shape, the present invention is not limited to this, and can also be applied to the entrance inclined portion 17°18.

Note that this invention is not limited to the above embodiments, but also includes
It goes without saying that various modifications can be made without departing from the gist of the invention.

[Effects of the Invention] As detailed above, the present invention provides a soldering device that has a simple configuration, reliably prevents solder short circuits, and promotes improvement in solder quality. can do.

[Brief explanation of the drawing]

FIG. 1 is a configuration explanatory diagram showing the main parts of a soldering device according to an embodiment of the present invention, FIG. 2 is an operating state diagram shown to explain the operation of FIG. 1, and FIG. Figure 1 is a state diagram showing the relationship between the printed wiring board and the molten solder surface, Figures 4 and 5 are configuration diagrams showing the equipment for conventional soldering, and Figure 6 is the printing by the equipment for conventional soldering. FIG. 7 is a state diagram showing the relationship between the wiring board and the molten solder surface, and FIG. 7 is a diagram showing the relationship between the printed wiring board and the beer pack point moving speed using a conventional soldering device. DESCRIPTION OF SYMBOLS 10... First guide rail, 11... Second guide rail, 12... Solder tank, 13... Printed wiring board, 1
4...Carrier, 15...Front wheel, 16...Rear wheel, 17°18...Inlet slope part, 19.20...
Slope for exit, 21...melting solder, 21a...beer pack point.

Claims (1)

[Claims] In a soldering apparatus in which a carrier on which a printed wiring board is mounted is conveyed by a guide rail and is immersed in a solder tank provided in the middle of the guide rail, the carrier is attached to the guide rail corresponding to at least the exit side of the solder tank. A soldering device characterized by having a parabolic slope.