JPS6235857B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention forms a large number of uneven waves on the top surface of jet waves of solder melt jetted from a jet port provided in a jet tank in a solder tank. This invention relates to a solder bath in which uneven waves of jet waves are moved in a direction intersecting the running direction of a printed circuit board.

[Conventional technology]

Conventionally, chip parts such as resistors and capacitors are temporarily attached with adhesive or the like, or printed circuit boards packed with electronic parts are soldered using a jet of melted solder.

[Problem that the invention seeks to solve]

In this case, the parts behind the chip components in the running direction of the printed circuit board and the parts where each chip component is close to each other are shaped like recesses, where air and other gases accumulate and the solder melt flows. Since the solder melt did not flow in, the solder melt did not adhere, or even if it did adhere, a cavity was formed and the solder melt 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 melted solder is applied for a long period of time.

This invention was made to eliminate the above-mentioned drawbacks, and provides a soldering bath that eliminates incomplete soldering caused by air bubbles and improves solder adhesion in secondary soldering. The purpose is to provide

[Means for solving problems]

The solder bath according to the present invention includes a large number of transparent conductors arranged in a staggered manner from which melted solder is ejected to form a large number of uneven waves that move in a direction intersecting the running direction of a printed circuit board on the top surface of a jet wave. A plate having a hole is provided in the jet tank, and a driving means is provided for reciprocating a large number of uneven waves in forward and backward directions in a direction intersecting the running direction of the printed circuit board.

[Operation] In the present invention, the solder melt is ejected from a large number of through holes arranged in a staggered manner provided in the plate, and uneven waves are formed on the wave surface of the jet wave. At that time, the plate moves forward and backward, so the uneven waves also move forward and backward.
Step back and expel any air bubbles to ensure complete soldering.

〔Example〕

FIG. 1 is a partially cutaway front view showing an embodiment of the present invention, and FIG. 2 is a perspective view showing an enlarged main part of FIG. 1.

In these figures, 1 is a printed circuit board, which is mounted on a carrier of a soldering device (not shown). 2 is a chip component such as a resistor or capacitor temporarily attached to the printed circuit board 1 with adhesive or the like;
3 shows the entire soldering tank of a soldering device (not shown). 4 is the solder bath body, 5 is the solder melt, 6
7 is a jet tank installed in the solder tank main body 4;
Reference numeral 8 denotes a jet port, and 8 an impeller for pressurizing and forcibly circulating the solder melt 5, which is rotated in a fixed direction by a motor 9. 10 is a flow tube, and 11 is a plate provided at the jet port 7, the main parts of which are shown in FIG.

In FIG. 2, reference numeral 12 denotes an engagement groove formed in the inner longitudinal direction of the jet port 7, into which the plate 11 is movably engaged. 1
Reference numeral 3 denotes a large number of through holes formed in the plate body 11 in a staggered manner. Referring again to FIG. 1, 14 denotes the plate 1.
1 is connected to the plate 11 via a rod 15.

Next, the operation will be explained. The solder melt 5 accommodated in the solder tank main body 4 is pressurized by rotation of the impeller 8 driven by the motor 9, and enters the jet tank 6 through the flow pipe 10. After that, solder melt 5
rises inside the jet tank 6 and reaches the plate 11, and is ejected from each through hole 13 in the direction of arrow A, producing a large number of uneven waves 5a.
is formed.

At the same time, due to the reciprocating drive of the piston 14, the plate body 11
Since the reciprocating movement of advancing and retreating in the direction of the arrow B is repeated, the large number of uneven waves 5a also repeats the reciprocating movement in the direction of the arrow B.

On the other hand, the printed circuit board 1 is dried after temporarily attaching the chip parts 2 with an adhesive or the like, then subjected to flux treatment, preheated by a preheating device, and transported to the solder bath 3. In the solder bath 3, the printed circuit board 1 travels in the direction of arrow C shown in FIG. 2 at a certain rising angle with respect to the horizontal line. The solder is soldered by the jet waves 5a of the solder melt 5, and the printed circuit board 1 is moved in the running direction by a large number of uneven waves 5a that intersect with the running direction C of the printed circuit board 1 and move alternately in the direction of the arrow B. On the other hand, the air bubbles attached to the rear part of the chip component 2 and the concave-shaped areas where each chip component 2 is close to each other are removed, so that the chips that are densely mounted on the printed circuit board 1 can be removed. The solder melt 5 adheres well to the parts 2 and lead wires.

Note that the soldering performance can be further improved by providing the means for creating the above-mentioned uneven waves 5a in two stages in the direction of movement of the printed circuit board 1, and by reversing the directions of movement of the uneven waves 5a. Also,
It goes without saying that the present invention can also be applied to a full-surface flow dip type solder tank.

〔Effect of the invention〕

As explained above, the present invention includes a jet tank which stores a solder melt in the solder tank main body and forcibly circulates the solder melt by pressurizing the solder melt with an impeller. In a soldering bath where printed circuit boards on which electronic components are mounted are soldered using jet waves ejected from a jet nozzle, a large number of uneven waves are formed on the top surface of the jet waves that move in a direction that intersects with the running direction of the printed circuit board. In order to do this, a plate having a large number of through holes arranged in a staggered manner from which the solder melt is ejected is provided in the jet tank, and
Since a driving means is provided that causes a large number of uneven waves to reciprocate forward and backward in a direction that intersects the running direction of the printed circuit board, the uneven waves on the top surface of the jet waves move in the direction that intersects the running direction of the printed circuit board. By moving the printed circuit board to the rear or both sides of the chip component in the running direction, or where the chip components are close together and have a concave shape, or where the lead wires are densely packed. It is possible to completely adhere the solder melt by removing air bubbles or gas stagnation in the solder, and the mechanism is simple because it is only necessary to move the plate forward and backward, and there is almost no failure even when exposed to high temperatures. It has the advantage that it does not.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view showing one embodiment of the present invention, and FIG. 2 is a perspective view of the main part of FIG. 1. In the figure, 1 is a printed circuit board, 2 is a chip component, and 3
4 is the entire solder tank, 4 is the solder tank body, 5 is the solder melt, 6 is the jet tank, 7 is the jet port, 8 is the impeller,
9 is a motor, 10 is a flow tube, 11 is a plate, 12 is an engagement groove, 13 is a through hole, and 14 is a piston.

Claims (1)

[Claims] 1. A jet tank is provided in which the solder melt is stored in the solder tank body, and this solder melt is pressurized by an impeller and forced to flow back. In a soldering bath for soldering a printed circuit board on which electronic components are mounted, the solder melt is applied to form a large number of concave and convex waves that move in a direction intersecting the running direction of the printed circuit board on the top surface of the jet wave. A plate body having a large number of through holes arranged in a staggered manner is provided in the jet tank, and the large number of uneven waves are moved forward and backward in a direction intersecting the running direction of the printed circuit board. A soldering bath characterized by being provided with a driving means for causing the soldering.