JPH0227971Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a structure of a solder gushing portion in an automatic soldering device, which is an apparatus for manufacturing printed circuit boards used in various electronic devices.

[Conventional technology]

As shown in FIG. 3, the solder gushing part in a conventional automatic soldering device has a solder receiving plate 3 having a dam plate 4a at the front end attached to a support 6 on the output side of the printed circuit board at the solder gushing port 2'. Therefore, it can be installed freely and adjusted up and down.

Therefore, when molten solder a gushes out from the gushing port 2', the solder a accumulates on the solder receiving plate 3 by the dam plate 4a, and the solder surface a' is formed flat, and the excess amount is removed. overflows over the top of the dam plate 4a as shown by the arrow,
Most of the gushing solder is returned to the solder bath by a guide plate 7 on the entry side of the printed circuit board 8.

[Problem that the invention attempts to solve]

However, in the above example, since the gushing solder is retained by the dam plate 4a, the solder surface a' is formed flat, and the angle at which it contacts the printed circuit board 8 is gentle, so that the solder surface of the printed circuit board 8 gradually increases. As the solder is separated from the surface of the printed circuit board 8, the solder does not cut easily, and as shown in FIG. The ends of the lead wires of adjacent circuit elements 8', 8' may be inadvertently shorted together by soldering, resulting in a condition b called "touch", or the dam plate 4 may
Since the solder surface a' hardly flows due to a, there are disadvantages such as an oxide film is easily formed.

The present invention addresses the drawbacks of the above-mentioned conventional examples and provides a structure of a solder gushing portion that reduces the incidence of solder defects.

[Problem that the invention attempts to solve]

A rising step section with a row of through holes arranged at the tip is provided on the printed circuit board delivery side of the solder outlet section.

[Effect]

The solder gushing out from the spout rises once due to the jetting force, but since there is only a low step on the solder receiving plate, the gushing solder flows without being accumulated, so the solder does not accumulate. The surface does not form a flat surface, but immediately forms a descending curved surface, and flows back into the solder tank from the edge through the stepped portion.As a result, the gushing solder instantly comes into contact with the part to be soldered on the bottom surface of the printed circuit board. As a result, there are no bumps or icicles, and the flow of solder at the outlet is prevented by the steps on the solder receiving plate between the input and output sides of the printed circuit board, preventing the solder from overflowing to the input side. By slowing down the flow toward the delivery side, soldering can be performed without trapping gas such as flux in the soldering part.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to an embodiment shown in the drawings. A gushing passage 2 for raising the solder a is provided in the center of the solder tank 1, and a gushing outlet 2' is formed at the upper end of the gushing passage 2. The base 5 of the solder receiving plate 3 is attached to the output side of the printed circuit board 8 in a vertically adjustable manner by means of a fixture 6 provided on the outside of the upper end of the gushing path 2. A stepped portion 4 higher than the upper surface of the receiving plate 3 is formed, and a large number of through holes 4', 4', etc. are arranged in the stepped portion 4 as shown in FIG. A guide plate 7 is attached to the entry side of the printed circuit board 8 so as to be adjustable up and down, and a level difference is maintained such that the upper surface of the guide plate 7 is lower than the step part 4 of the solder receiving plate 3.

The structure of the stepped portion 4 of the solder receiving plate 3 is shown in Fig. 2b.
As shown in FIG.
₁ , or as shown in Fig. 2c, the material has different thicknesses to form a step ₄₂ , or as shown in Fig. 2d, a large number of steps are formed on the top surface of the solder receiving plate 3. By inserting the mounting screw 5' through the mounting hole 4 _{'' drilled in the adjustment plate 43} to attach the adjustment plate 43 having a row of through holes 4 _' , and moving the adjustment plate ₄₃ up and down. Any means may be used, such as adjusting the level difference or forming the level difference using overlapping materials.

Above the solder outlet is the outlet 2'.
The printed circuit boards 8 are sequentially transferred at a constant inclination relative to the base plate.

The present invention is constructed as described above, and the molten solder a rises in the gushing path 2 toward the printed circuit board 8, which is transferred at a constant angle of inclination just above the gushing port 2'. 'The upper end of the guide plate 7
Since the upper end surface is lower than the step 4 of the solder receiving plate 3, the flow of molten solder is directed toward the printed circuit board 8.
A large number of flows A ₄ are formed in the direction opposite to the direction of movement (arrow), and the remaining part on the solder receiving plate 3 forms a solder surface A ₁ as shown by the curved line and rapidly descends, forming the solder surface A 1 on the solder receiving plate 3 .
The solder flows through the through hole 4' and the end edge as flows a ₂ and a ₃ while being suppressed by the solder bath 1 and circulates therein.

In this way, the solder surface _A1 rapidly descends, so even if the solder contacts the bottom surface of the printed circuit board 8 passing directly above it, the solder can be easily cut off from the end of the lead wire, creating extremely ideal soldering conditions. is obtained.

[Effect of idea]

With the structure described above, the solder mainly flows in a direction different from the direction in which the printed circuit board is transported, so that flux gas is not trapped in the soldered parts of the lead wires and pattern wiring of the circuit elements 8' and 8'. Reliable soldering is possible.

In addition, since the solder cuts better, the ``iccicle'' and ``touch'' conditions that have been encountered in the past are eliminated, and it is possible to solder in an ideal shape.

Also, unlike previous solder solder plates 3, sufficient flow is obtained, eliminating long-term air contact, resulting in a significant reduction in the formation of oxide films.
Solder loss is reduced, and since the solder surface flows in the same direction as the printed circuit board on the delivery side of the printed circuit board, the printed circuit board can be transferred in synchronization with this solder flow, thereby sufficiently increasing the feeding speed. It is a highly practical idea that has many excellent effects, such as being able to improve productivity.

[Brief explanation of the drawing]

Figures 1 and 2 show an embodiment of the present invention, in which Figure 1 is a longitudinal cross-sectional side view of the main parts of the invention, Figure 2a is a perspective view of the main parts, Figure 2b, Figure 2 c, Figure 2 d
2A is a longitudinal side view showing a configuration example different from that in FIG. 2a, FIG. 3 is a partial longitudinal side view of a conventional example,
FIG. 4 is a perspective view of the same components as above, and FIG. 5 is a partial side view of the printed circuit board showing a defective state. 2... Gushing path, 2'... Gushing outlet, 3... Soldering part, 4... Stepped part.

Claims (1)

[Scope of utility model registration request] In an automatic soldering machine that solders circuit elements to the printed circuit board while transferring a printed circuit board on which circuit elements have been temporarily installed in a certain direction, the molten solder flowing out toward the printed circuit board is Corresponding to the delivery side of the printed circuit board, an upward step for suppressing the flow rate of solder is provided, and a plurality of through holes are bored in the upper surface of the step,
A structure of a solder gushing part in an automatic soldering apparatus, characterized in that solder overflows and circulates through the stepped part and the through hole.