JPH0451023Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] This invention is based on each jet wave of the solder melt that is jetted from a large number of through holes formed in the jet that is slidably provided at the jet opening of the jet tank. Therefore, the present invention relates to a jet type solder bath for performing soldering.

[Conventional technology]

Conventionally, when soldering electronic components such as resistors and capacitors temporarily attached with adhesive, or printed circuit boards with densely packed electronic components using a jet of melted solder, the direction of travel of the printed circuit board is The parts behind the electronic components and the parts where each electronic component is close to each other are shaped like recesses, where air and other gases stay and the solder melt does not flow in, so the solder melt does not adhere. Or, even if it adhered, a cavity was formed and it did not adhere completely. If bubbles are generated during one soldering process, there is a drawback that the bubbles cannot be removed even if a jet of solder solution is applied for a long period of time.

Therefore, in order to eliminate the above-mentioned drawbacks and to eliminate incomplete soldering caused by air bubbles, the present inventor first provided a cylindrical jet at the jet port above the solder bath, and this jet Through-holes are formed, and these through-holes are formed with an inclination of a required angle alternately in the front and rear directions of the running direction of the printed circuit board with respect to the vertical line of the jet fluid to further improve the adhesion of the solder melt. We proposed a soldering bath designed to
(Refer to Publication No. 87658).

Hereinafter, the above solder bath will be explained based on the drawings.

Figures 3a to 3e show an example of the previously proposed solder bath, with Figure 3a being a schematic perspective view and Figure 3b being a schematic perspective view.
3 is an enlarged side sectional view taken along the - line in FIG. 3a, FIG. 3c is an enlarged plan view showing a portion of the first jet tank in FIG. 3a, and FIGS. 3d and e are FIG. c-
4a and 4b show the shape of the jet wave, FIG. 4a is a plan view, and FIG. 4b is a sectional view taken along the line - of FIG. 4a.

In these figures, reference numeral 1 denotes a printed circuit board, which is mounted on a substrate holder of a carrier or conveyance chain of a soldering device (not shown). 2 is an electronic component such as a resistor or a capacitor temporarily attached to the printed circuit board 1 with adhesive or the like; 3 is a solder bath;
The tank type is shown. The solder tank 3 is formed into two tanks by a partition wall 3a provided at the center. Reference numerals 4 and 5 denote a primary tank and a secondary tank of the solder tank 3, which are arranged in sequence in the running direction of the printed circuit board 1 (direction of arrow A). 6 and 7 are the solder melt in the primary tank 4 and secondary tank 5; 8 and 9 are the solder melt in the primary tank 4 and secondary tank 5;
With a first jet tank and a second jet tank installed inside,
The solder melt 6 is driven by a motor (not shown).
7 is pressurized to force a jet. 10,1
Reference numeral 1 indicates a jet port of each of the jet tanks 8 and 9. Reference numeral 12 denotes a cylindrical jet; 12a, as shown in FIG. Possibly engaged. 13A and 13B are arranged in a direction (direction of arrow B) that intersects the running direction (direction of arrow A) of the printed circuit board 1, and are arranged at a required angle α.
The through holes 13A are shown in Fig. 3d as an example.
As shown in Fig. 3e, the through hole 13B is inclined upward and forward with respect to the traveling direction (direction of arrow A) of the printed circuit board 1, whereas the through hole 13B is inclined backward as shown in Fig. 3e, and the direction of the inclination is are formed alternately and at equal intervals in the longitudinal direction of the jet fluid 12. Reference numeral 14 denotes a device that repeatedly moves the jet fluid 12 back and forth by a distance of one pitch p of the through hole 13A or 13B in a direction (arrow B direction) that intersects the traveling direction (arrow A direction) of the printed circuit board 1. A crank device is shown as an example. 15 is a rod, one end of which is connected to the jet fluid 12, and the other end connected to the flywheel 16. 17 is a motor for driving the crank device 14. Incidentally, the crank device 14 is provided apart from the travel path so as not to interfere with the travel of the printed circuit board 1. 18 is a jet provided at the jet port 11, and 19 is an outlet for the solder melt 7.

Next, the operation will be explained.

The solder melt 6 in the primary tank 4 is pressurized by the drive of a motor (not shown), rises from the first jet tank 8 through the jet port 10, reaches the jet fluid 12, and flows through each through hole 1.
Jet waves 6a and 6b are formed by the jets flowing diagonally upward from 3A and 13B, respectively, and the wave crests formed by the jet waves 6a and 6b, respectively, in the front and rear directions in the running direction of the printed circuit board 1 (direction of arrow A). Parts 6c, 6d
is formed. Note that L is the wave head 6c, 6
Indicates the level of d. Simultaneously with the formation of the jet waves 6a and 6b, the jet fluid 12 repeats reciprocating motion in the direction of arrow B due to the reciprocating drive of the crank device 14, so that a large number of jet waves 6a and 6b also repeat reciprocating motion in the direction of arrow B.

After the electronic components 2 are temporarily attached to the printed circuit board 1 using an adhesive or the like, the printed circuit board 1 is dried, then subjected to a flux treatment, and then preheated in a preheating device.
transported to. The printed circuit board 1 is placed in the solder bath 3 at an upward angle θ with respect to the horizontal line, as shown in FIG. 3b.
and travel in the direction of arrow A. And printed circuit board 1
After being soldered by a large number of jet waves 6a and 6b moving in the direction of arrow B intersecting the running direction (direction of arrow A), the printed circuit board 1 further advances to
The next tank 5 is reached, and soldering is performed using the solder melt 7.

In the secondary tank 5, the solder melt 7 is pressurized by the rotation of a motor (not shown), and is transferred to a second jet tank 9.
The jet wave 7a is ejected through the outlet 19 in a direction opposite to the running direction of the printed circuit board 1 (direction of arrow A).

[The problem that the idea attempts to solve]

By the way, in the solder tank 3 proposed earlier as described above, as shown in FIGS. Since the wave heads 6c and 6d thus formed are at the same height level L, the printed circuit board 1 traveling in the direction of the arrow A at the rising angle θ has a height h ₁ with respect to the jet wave 6b. Soldering is carried out by the amount of solder melt 6, but the jet wave 6
For a, the height h ₂ due to the rise of the printed circuit board 1
Since only an amount of the solder melt 6 is applied to the printed circuit board 1, there is a problem in that the contact is weak, especially at the rear part of the electronic component 2, and sufficient soldering is not performed.

Therefore, in order to sufficiently perform soldering by the jet wave 6a, if the level L of the wave heads 6c and 6d is raised and the heights _h1 and _h2 are increased, the wave head 6d of the jet wave 6b will There was a problem that the solder melt 6 covered the top surface of the printed circuit board 1.

5a to 5c show a soldering device used in the conventional method for soldering printed circuit boards disclosed in Japanese Patent Publication No. 63-15063, and FIG.
Figure a is a partially cutaway perspective view, Figure 5 b is a perspective view showing the nozzle of Figure 5 a, Figure 5 c is a perspective view of Figure 5 b.
It is a figure showing the usage state of.

In these figures, 31 is a solder bath, 32 is a nozzle as a laminar wave forming means, 33 is a nozzle as a turbulent wave forming means, 34 is a turbulent wave forming plate fixed to the nozzle 33, and 35 is a nozzle as a laminar wave forming means. Turbulent wave forming plate 34
The solder melt 36 as shown in FIG. 5c is ejected by a pressurizing means from a large number of ejection ports formed in the wafer, thereby forming a large number of wave crests 37. And solder melt 3
Based on the flow by the pressure means 6, the wave crest 37 is brought into a turbulent state and irregularly fluctuates vertically and horizontally.

By the way, in the conventional printed circuit board soldering method shown in FIG. 5, the turbulence caused by the wave crests 37 is irregular and inconsistent, and the parts that the solder melt 36 hits are different for each printed circuit board. There was a problem in that there were parts where the solder melt 36 did not adhere or dripped, and the reliability of soldering was low.

This idea was made to solve the above problem, and the wave head of the jet wave jetted from each jet port is positioned in a straight line in the direction perpendicular to the running direction of the printed circuit board, so that the solder melt flows. The purpose of the present invention is to obtain a jet-flow type solder tank that allows sufficient adhesion.

[Means to solve the problem]

In the jet soldering bath according to this invention, a large number of through holes are formed in the jet fluid of the solder bath, and the wave head formed by each jet wave flowing from these many through holes is aligned in the traveling direction of the printed circuit board. A large number of through holes are formed in the jet fluid so as to be aligned in a straight line at right angles to the vertical line, and are inclined at a required angle alternately toward the front and rear of the running direction of the printed circuit board with respect to the vertical line. be.

[Operation] In this invention, the wave head of each jet wave is formed in a straight line in the direction perpendicular to the running direction of the printed circuit board, so that the amount of solder melt that hits the printed circuit board is almost the same. Therefore, bubbles or gas stagnation, especially in the rear part of the electronic component, are removed and the solder melt is completely adhered.

〔Example〕

1A and 1B show an embodiment of the present invention, FIG. 1A is a schematic perspective view, FIG. 1B is an enlarged sectional view taken along the line - in FIG. 1A, and FIGS. b
2 shows the shape of the jet wave in FIG. 1, FIG. 2a is a plan view, and FIG. 2b is a sectional view taken along the line - in FIG. 2a.

In these figures, the same reference numerals as in FIGS. 3 and 4 indicate the same parts, and 21A and 21B are through holes that form a guide path consisting of deep holes, and as shown in FIG. 2b, the jet fluid 12 It is formed obliquely at a predetermined angle β with respect to a vertical center line c set perpendicularly to the radial direction from the axis. Also, through hole 2
As an example, 1A has a through hole 21 located upwardly and forwardly with respect to the running direction (direction of arrow A) of the printed circuit board 1.
B is inclined rearward, and the through holes 21A and the through holes 21B are formed alternately and at equal intervals in a direction (direction of arrow B) intersecting the longitudinal direction of the jet fluid 12 (direction of arrow A).

Next, the operation will be explained.

The solder melt 6 in the primary tank 4 rises from the first jet tank 8 through the jet port 10 and reaches the jet fluid 12, and is vigorously jetted diagonally upward from each through hole 21A, 21B, and is attached to a printed circuit board, respectively. 1 running direction (arrow A
Jet waves 6e and 6f are formed in the front and rear directions (direction), and at the same time, wave heads 6g and 6h are formed continuously on the vertical center line c of the jet fluid 12 and in a straight line in the axial direction of the jet fluid 12. It is formed.

Further, as the jet fluid 12 repeats reciprocating motion in the direction of arrow B due to the reciprocating drive of the crank device 14, a large number of jet waves 6e, 6f and wave heads 6g, 6h are generated.
also repeats reciprocating movement in the direction of arrow B.

Therefore, the electronic components 2 of the printed circuit board 1 traveling at the rising angle θ are at the same level L and at the same height h ₃ by the jet waves 6e and 6f, regardless of the direction of the jet waves 6e and 6f. Wave head 6 formed in
g, 6h, sufficient soldering is performed, and the rear part of the electronic component 2 and the electronic component 2 are close together.
The solder melt 6 also adheres well to the concave portions.

Note that the other operations are the same as those of the conventional example, so the explanation thereof will be omitted.

Further, in the above embodiment, the solder bath 3 is described as a two-tank type, but it may be a one-tank type with only the primary tank 4.

Furthermore, although the through holes 21A and 21B are formed symmetrically with respect to the vertical center line c, the wave heads 6g and 6
If h is formed on a straight line in the axial direction of the jet fluid 12, the through holes 21A and 21B do not need to be symmetrical with respect to the vertical center line c.

[Effect of idea]

As explained above, this device forms a large number of through holes in the jet of the solder bath, and the wave head formed by each jet wave flowing from these many through holes is aligned with the running direction of the printed circuit board. A large number of through holes are formed in the jet fluid so that they are located on a straight line in the perpendicular direction, and are inclined at a required angle alternately in front and rear of the running direction of the printed circuit board with respect to the vertical line. In addition, the wave head formed in a straight line by the jet wave of the solder melt that is rectified diagonally upward from the through hole that forms the guide path consisting of a deep hole and jets out forcefully, causes the wave head to form a straight line in the running direction of the printed circuit board. On the other hand, bubbles or gas stagnation in the rear part of the electronic component or in the part where the electronic component is close to each other forming a recess can be easily removed and the solder melt can be completely adhered, further improving the soldering performance. It has the advantage of being able to

[Brief explanation of drawings]

Figures 1a and b show one embodiment of this invention, with Figure 1a being a schematic perspective view, Figure 1b being an enlarged sectional view taken along the - line in Figure 1a, Figures 2a and 2b showing an embodiment of the invention. b
shows the shape of the jet wave in Fig. 1, Fig. 2 a is a plan view, Fig. 2 b is a sectional view taken along the - line in Fig. 2 a, and Figs. 3 a to e are the shapes proposed earlier. FIG. 3a is a schematic perspective view, FIG. 3b is an enlarged side sectional view taken along the line - in FIG. 3a, and FIG. 3c is a schematic perspective view of FIG. 3a. An enlarged plan view showing a portion of the first jet tank, Figures 3 d and e are
4a and 4b show the shape of jet waves, 4a is a plan view, and 4b is a sectional view taken by 4b lines in Figure 4a. The sectional views of FIGS. 5a to 5c show a soldering device used in the conventional soldering method for printed circuit boards. FIG. 5a is a partially cutaway perspective view, and FIG. A perspective view showing the nozzle of Figure a, Figure 5c
5b is a diagram showing the state of use of FIG. 5b; FIG. In the figure, 1 is a printed circuit board, 2 is an electronic component, 3 is a solder bath, 4 is a primary bath, 5 is a secondary bath, 6 and 7 are melted solder, 6e and 6f are jet waves, and 6g and 6h are waves. head, 8 is the first jet tank, 9 is the second jet tank, 1
0 and 11 are jet ports, 10a is a guide portion, 12 is a jet fluid, 12a is an engaging portion, 14 is a crank device, 21
A and 21B are through holes.

Claims (1)

[Scope of utility model registration request] The jet tank includes a jet tank that pressurizes and jets the solder melt contained in the solder tank, and has a large number of through holes that form jet waves with the solder melt from the jet port above the jet tank. is provided so as to be able to reciprocate and slide in the longitudinal direction of the jet port, further sliding the jet fluid back and forth and soldering a printed circuit board by each of the jet waves jetted from the plurality of through holes. In this step, the plurality of through holes are formed in the jet fluid so that the wave head of the jet wave is on a straight line in a direction perpendicular to the running direction of the printed circuit board, and the jet wave is arranged in the running direction of the printed circuit board with respect to the vertical line thereof. A jet-flow solder bath characterized by being formed with a predetermined angle of inclination alternately on the front and rear sides.