JPH02121768A - Jet type solder tank - Google Patents

Abstract

PURPOSE:To prevent the oxidation of a solder molten liquid caused by a drop of a jet wave in a primary tank and to prevent the fluctuation of the jet wave in a secondary tank by forming a communicating hole by which the solder molten liquid in the primary tank and the solder molten liquid in the secondary tank flow and hold a liquid level of the same level. CONSTITUTION:A communicating hole 41 is formed on a partition wall 41. Even if a liquid level 15c of a solder molten liquid 15 in a primary tank 13 drops and a liquid level 16d of a solder molten liquid 16 in a secondary tank 14 ascends, the solder molten liquid 16 in the secondary tank 14 passes through the communicating hole 41 and flows in the direction as indicated with an arrow D. Therefore, each liquid level 15c, 16d can always hold the same level. In such a way, in the primary tank, the oxidation of the solder molten liquid caused by a drop of a jet wave is prevented, and the consumption of the solder molten liquid can be decreased. In the secondary tank, the fluctuation of a jet wave in a second jet tank can be prevented, and soldering of a printed board having a good quality can be executed.

Description

[Detailed Description of the Invention] [Industrial Applicability] This invention makes it possible to maintain the liquid level of each solder melt in the primary tank and the secondary tank at the same level. This relates to a jet soldering bath.

[Conventional technology]

Figure 2 is a side sectional view showing an example of a conventional jet-type solder bath;
FIG. 3 is an enlarged side sectional view showing a portion of the second jet tank in FIG. 2. FIG. In these figures, reference numeral 1 denotes a printed circuit board, and a solder joint (not shown) is attached to a carrier of the device or a board holder of a conveyance chain. 2 is a chip component temporarily attached to the printed circuit board 1 with an adhesive; 3 is an electronic component such as a resistor, a capacitor, an IC, etc. mounted on the printed circuit board 1; and 4 is a lead wire of the electronic component 3. 11 is a two-tank type soldering tank, 12 is a partition wall, and 13.14 is a primary tank and a secondary tank of the solder tank 11, which are arranged in sequence in the running direction of the printed circuit board 1 (direction of arrow A). There is. 15
．． 16 is the solder melt in the primary tank 13 and the secondary tank 14.

Reference numerals 17 and 18 denote a first jet tank and a second jet tank disposed in the primary tank 13 and the secondary tank 14, and the solder melting tanks 15 and 16 are pressurized by driving a motor 19 and 20. Jet outlet 2
1. Force the jet from 22. And the jet port 21
From there, first jet waves 15a, 1 are formed on the printed circuit board 1, which are approximately symmetrical with respect to the front and back direction of the running direction (arrow entry direction).
Form 5b. Furthermore, reference numerals 17a and 17b are jet plates that form the first jet waves 15a and 15b.

Reference numeral 23 denotes a storage tank for storing the solder melt 16 flowing out from the jet port 22, which jets the solder melt 16 in a direction opposite to the running direction of the printed circuit board 1 (arrow A direction) to generate a second jet wave 16a. Form. 24 is a side plate of the storage tank 23;
Reference numeral 5 denotes a weir plate fixed to the storage tank 23, 26 refers to an outflow portion that allows the solder melt 1B in the storage tank 23 to flow out in the same direction as the running direction of the printed circuit board 1 (direction of arrow A), and 27 refers to the outflow portion. A movable weir plate 28 is screwed onto the movable weir plate 27 to form an overflow wave 16c of a desired shape from the portion 26, and is adjusted by an adjusting screw as a means for moving the movable weir plate 27 up and down. is a through hole 29 formed at the bottom of the storage tank 23.
It is loosely fitted. 3o, the adjustment screw 28 is connected to the through hole 29.
The karabuki is a washer that prevents it from coming out. 31 and 32 are impellers that pressurize and forcefully circulate the solder melts 15 and 16, and are rotated by motors 19 and 20. 33.
34 is a flow tube, 35.36 is the solder melt 15, 16
37.38 is the recirculation port through which the solder melt 15,
This is a heater that heats 18.

Next, the operation will be explained.

The solder melt 15 in the primary tank 13 is pressurized by the drive of the motor 19, passes through the flow pipe 33, rises in the first jet tank 17, and is jetted out from the jet port 21. On the other hand, the printed circuit board 1 is dried after temporarily attaching the chip components 2 with an adhesive or the like and mounting the electronic components 3, and then subjected to flux treatment and then preheated by a preheating device (not shown). , and transported to the solder bath 11. Printed circuit board 1 in solder bath 11
As shown in FIG. 2, the vehicle travels in the direction of arrow A at an upward angle θ with respect to the horizontal line. Next, the printed circuit board 1
Jet tank 17. It runs in the order of the second jet tank 1B.

First, in the first jet tank 17, the first jet waves 15a, 15
b to remove air bubbles between the chip components 2 and 2, and as shown in FIG.
Then, the solder melt 15 is sufficiently applied to the lead wires 4. At this time, a bridge 39a, an excessive built-up portion 39b, and a gap 39c are formed between the chip components 2.2, and an excessive amount of solder melt 15 adheres to the lead wire 4. Secondary tank 1
4, the solder melt 16 is pressurized by the rotation of the motor 20, passes through the flow pipe 34, enters the second jet tank 18, and is jetted from the jet port 22 to the reservoir tank as shown in FIG. 23 and is stored, and the printed circuit board 1
A second jet wave 16a is formed by jetting in a direction (direction of arrow B) opposite to the traveling direction (direction of arrow A).

Note that when the printed circuit board 1 has not reached the second jet tank 18, the solder melt 16 forms a reservoir 16 due to the surface tension of the solder melt 16 and flows out of the outflow part 26, as shown in FIG. It is made to prevent leakage.

Next, when the printed circuit board 1 comes into contact with the second jet wave 16a, the printed circuit board 1 presses the solder melt 16, so that the solder melt 1 also flows from the outflow portion 26, as shown in FIG.
6 overflows in the direction of arrow C, and an overflow wave 16c is formed.

Therefore, in the second jet tank 18, the solder melt 16 is transferred to the second jet wave 16a in the opposite direction to the running direction of the printed circuit board 1 (the direction in which the arrow enters) and the overflow wave 1 in the same direction.
6c, a secondary tank 14 having both a jet type and a flow dip type is formed.

In addition, by adjusting the height of the movable weir plate 27, the outflow speed of the overflow wave 16c is set to the same speed as the running speed of the printed circuit board 1, or almost the same speed, and soldering is performed. As shown in Figure 6, 1
Bridge 39a caused by soldering in the next tank 13
, remove the excess build-up portion 39b or icicle 39c, and perform final soldering. Further, the temperature of the solder melt 16 in the secondary tank 14 and the temperature of the solder melt 15 in the primary tank 13 are the same or have a temperature difference.

[Problem to be solved by the invention]

By the way, in the conventional soldering bath as mentioned above, 1
In the next tank 13, the solder melt 15 is applied to the printed circuit board 1.
As soldering is performed by adhering to solder, the amount of solder melt 15 soldered decreases, and therefore the level of the liquid surface 15c of solder melt 15 decreases. In addition, in the secondary tank 14, excess solder that has adhered in the primary tank 13,
That is, the bridge 39a, built-up portion 39b, and icicle 39c are removed by the second jet wave 16a. Therefore, this removed solder melts into the solder melt 16 in the secondary tank 14, so that the solder melt 16 in the secondary tank 14
The level of the liquid level 16d of No. 6 rises. Therefore, when the number of printed circuit boards 1 to be soldered increases, the level 15c of the solder melt 15 in the primary tank 13 decreases and the level 16d of the solder melt 16 in the secondary tank 14 decreases.
The level of will increase significantly. Therefore, the primary tank 13
In this case, the difference in height between the first jet waves 15a and 15b becomes large, and the force of the falling of the first jet waves 15a and 15b increases, and the liquid surface 15c is roughened and oxidized, resulting in oxidation of the solder melt 15. There was a problem in that a lot of solder particles were generated due to objects.

On the other hand, in the secondary tank 14, the rotation speed of the impeller 32 is set constant even if the amount of the solder melt 16 increases, so that the shape of the second jet wave 16a and the height of the reservoir 16b are There was a problem that the soldering process changed and the desired soldering could not be achieved.

This invention was made to solve the above-mentioned problems, and is a jet type that enables the liquid level of each solder melt in the primary and secondary solder tanks to be maintained at the same level at all times. The purpose is to obtain a solder bath.

(Means for Solving the Problems) A jet type solder tank according to the present invention includes a first jet tank that stores a solder melt and forcibly sprays the solder melt by pressurizing the solder melt with an impeller. A primary tank provided with a jet tank and a secondary tank provided with a second jet tank are formed into two tanks by a partition wall, and are arranged sequentially in the running direction of the printed circuit board,
A communication hole is formed in the partition wall through which the melted solder in the primary tank and the melted solder in the secondary tank can flow and maintain the same liquid level.

[Effect]

In this invention, even if the amount of solder melt in the secondary tank increases and the liquid level rises, or even if the amount of solder melt in the primary tank decreases and the liquid level falls, Since the solder melt in the secondary tank flows into the primary tank through the communication hole, the solder melt in the secondary tank flows between the primary tank and the
The liquid level in the next tank can be maintained at the same level at all times.

〔Example〕

FIG. 1 is a side sectional view showing an embodiment of the present invention, in which the same reference numerals as in FIG. 2 indicate the same parts, and 41 is a communicating hole formed in the partition wall 12.

By forming the communication hole 41 in the partition wall 12 in this way, the liquid level 15c of the solder melt 15 in the primary tank 13 is lowered, and the level 15c of the solder melt 16 in the secondary tank 14 is lowered, as in the conventional case. Even if the liquid level 16d rises, the solder melt 1 in the secondary tank 14
6 flows in the direction indicated by the arrow through the communication hole 41, so that each liquid level 15c16d can be maintained at the same level at all times. Note that the communication hole 41 may be formed below the partition wall 12 so as not to give a shadow U to the temperature near the liquid surface 15c, 16d of each solder melt 15, 16.

[Effect of the invention] As explained above, the present invention accommodates solder melt,
Two tanks are separated by a partition wall: a primary tank with a first jet tank for forcefully spouting this solder melt by applying pressure with an impeller, and a secondary tank with a second jet tank. The solder melt in the primary tank and the solder melt in the secondary tank flow through the partition wall to maintain the same liquid level. Since the communication hole was formed, the liquid level of the solder melt in the primary tank and the second
Since the liquid level of the solder melt in the next tank can be maintained at the same level at all times, the oxidation of the solder melt due to falling jet waves is prevented in the first tank, reducing consumption of the solder melt. In the secondary tank, it is possible to prevent fluctuations in the jet waves in the second jet tank, which has advantages such as economical and high-quality soldering of printed circuit boards.

[Brief explanation of drawings]

FIG. 1 is a side sectional view showing an embodiment of the present invention, FIG. 2 is a side sectional view showing an example of a conventional jet soldering bath, and FIG. 3 is a portion of the second jet soldering bath shown in FIG. FIG. 4 is a side view showing a printed circuit board with excess solder melt attached to it, and FIG. 5 is a printed circuit board being soldered in the second jet tank of FIG. 3. Side sectional view showing the state, No. 6
The figure is a side view showing the state in which the excessively attached solder of FIG. 4 has been removed and the final soldering has been performed. In the figure, 1 is a printed circuit board, 2 is a chip component, 3 is an electronic component, 4 is a lead wire, 11 is a solder bath, 12 is a partition wall, 1
3 is the primary tank, 14 is the secondary tank, 15.16 is the solder melt,
15c and 16d are liquid levels, 17 is a first jet tank, 18 is a second jet tank, 32 is an impeller, and these are communication holes. Figure Figure

Claims (1)

[Claims] A soldering tank used to solder printed circuit boards mounted with chip components and/or electronic components having lead wires, which stores melted solder and forcibly sprays out the melted solder by pressurizing it with an impeller. 1st to let
A primary tank provided with a jet tank and a secondary tank provided with a second jet tank are formed into two tanks by a partition wall and are arranged sequentially in the running direction of the printed circuit board, A jet-flow type solder tank, characterized in that a communication hole is formed through which the solder melt in the primary tank and the solder melt in the secondary tank flow to maintain the same liquid level.