JPH06260753A - Partially soldering apparatus by use of jet solder tank - Google Patents

Abstract

PURPOSE:To obtain a partially soldering apparatus wherein molten solder levels are optionally arranged above a soldering nozzle, the soldering nozzle can be lessened in size, and the molten solder levels can be kept still, stable, and equal in height by a method wherein an inlet pipe is jointly provided for jet nozzle, and a soldering nozzle communicating with the inlet pipe is provided. CONSTITUTION:A jet screw 4 equipped with a motor 3, a flow pipe 5 provided with one open end in which the jet screw 4 is provided as inscribed and other open end connected to a jet nozzle, and a soldering nozzle 9 connected to an inlet pipe 7 jointly provided to a jet nozzle 6 are provided inside a solder tank 1 filled with molten solder 2. For instance, when the height of an inlet 8 is equal to or larger than that of the upper end of the soldering nozzle 9, the jet screw 4 is rotated to enable molten solder to fill the soldering nozzle 9 from the inlet pipe 7 and to overflow out of the soldering nozzle 9 together with a surface oxide film, and solder is stabilized in temperature. If the jet screw 4 is stopped, molten solder inside the inlet pipe 7 and the soldering nozzle 9 is kept still and level with the upper end of the opening of the nozzle 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a jet soldering device for partially soldering a printed board on which electronic parts are mounted.

[0002]

2. Description of the Related Art A conventional partial soldering apparatus using a jet solder bath is one in which a jet screw, a flow pipe, and a jet nozzle connected to a motor are installed in a solder bath containing molten solder. The flow pipe contains a jet screw at one end and is connected to the lower part of the jet nozzle at the other end. The shape of the jet nozzle can be freely changed according to the printed circuit board to be partially soldered, and a plurality of jet holes can be prepared if necessary. Here, the jet screw is set lower than the liquid level of the molten solder, and the upper end of the jet nozzle is set higher than the liquid level.

When the jet screw is rotated by driving the motor, the solder in the flow pipe is pushed out and overflows from the upper end opening of the jet nozzle. At this time, a plane is formed by the solder, and the printed circuit board is brought into contact with the flat surface from above, so that the soldering can be performed.

According to this soldering method, even if a component has already been mounted and mounted at an adjacent portion on the printed board, the soldering work can be performed without exerting an excessive heat effect on the adjacent component. The jet solder bath can remove the oxide film on the soldering flat surface with a relatively simple mechanism, and can keep the soldering temperature stable because the solder is fluidized and reduced. Further, in this method, since a large number of points can be soldered at the same time, the processing time for one printed circuit board can be minimized and the facility cost can be reduced.

[0005]

For good soldering of a printed circuit board, the time during which the soldered portion is immersed in the molten solder and the delicate speed at the time of separating from the solder surface are important factors. There is. As a basic environmental condition for that, it is necessary that the solder liquid surface is stable. If even a little up and down occurs on the plane, the contact time with the solder surface fluctuates, and the set infiltration time cannot be obtained. Also, the speed at which the solder separates from the solder will change, and the solder will not be finished in the optimal shape that was planned.

In the above jet soldering apparatus, the solder liquid surface in contact with the printed circuit board is located at the uppermost portion of the molten solder,
Since the pressure for pushing up is directly transmitted, it is easily affected by fluctuations in output of the jet motor, turbulent flow caused by pushing out liquid solder, and a decrease in flow rate caused by adhesion of solder residue on the inner wall of the flow tube. For example, by changing the shape of the jet nozzle and narrowing the total area of the solder flat area formed in each opening below a certain level, even if the motor rotation speed is finely adjusted, the surface will rise and fall sharply for soldering use. It will be intolerable. Therefore, in the jet solder bath, it is impossible to solder a small portion with a minute nozzle. That is, in order to eliminate and stabilize the unevenness of the soldering plane, the area of the opening of the jet nozzle must be set to a certain size or more.

It is necessary to lift the solder to the upper end of the jet nozzle by the jet screw and keep it at the optimum liquid level so that it does not flow out from the edge of the jet nozzle. The vertical movement of the nozzle occurs, which is impossible regardless of the size of the nozzle. Since the solder must always be continuously flown from the nozzle of the jet solder bath, the thickness of the solder that flows down is a major obstacle for a substrate that requires fine soldering. The thickness of this solder flow limits the limit that can be minimized at the soldering point,
It also makes it impossible to solder the nozzles so that the gap between them is narrow.

When the printed circuit board surface needs to be soldered in several places, a plurality of jet holes of arbitrary shape must be prepared. However, the size of the upper area of each jet opening is large and small. The amount of solder flowing out changes depending on the degree of density of the arrangement. This occurs because the resistance received as the solder fluid is different at each position. Therefore, a difference in height occurs on the upper surface of the solder overflowing from the edge of the opening, and it becomes difficult to apply uniform soldering conditions to the entire surface of the printed board.

In the conventional jet solder bath, the disturbance of the flow velocity of the molten solder causes vertical oscillation or turbulence, and the solder surface of the jet nozzle opening is unstable unless it is provided with a sufficient width and a sufficient solder outflow amount. Becomes That is, the mechanism that uses the jetted solder as it is for soldering causes the above-mentioned problems. This invention has been made in order to solve these problems, it is possible to arbitrarily arrange a plurality of solder planes on the soldering nozzle,
Further, it is an object of the present invention to provide a partial soldering apparatus using a jet solder bath in which minute shapes are possible and the surfaces of these solders are quietly stable and all have the same height.

[0010]

In order to achieve the above object, in the partial soldering apparatus of the present invention, a jet screw, a flow tube, and a soldering nozzle are accommodated in a solder bath containing molten solder, A motor is attached to the jet screw, the flow pipe encloses the jet screw at one end and a jet nozzle is connected to the other end, and the soldering nozzle is connected to an inlet pipe provided in a pair with the jet nozzle.

The position at which the introduction pipe is attached can be inside or outside the jet nozzle.

The height of the introduction portion where the introduction pipe receives the molten solder from the jet nozzle can be the same as or higher than that of the upper end of the soldering nozzle, or lower than that, and is low. In this case, the height of the jet nozzle is set so that the height of the solder plane on the jet nozzle is the same as the upper end of the soldering nozzle.

When the height of the introducing portion is lower than the upper end of the soldering nozzle, a flow restricting plate is provided on the upper edge of the jet nozzle, a restricting valve is provided in the jet nozzle, or a motor is installed inside the introducing pipe. The attached jet screw can be provided to allow the solder to flow out from the upper end of the soldering nozzle.

[0014]

In the jet solder bath configured as described above, when the height of the introducing portion is higher than or equal to the upper end of the soldering nozzle, when the jet screw rotates, the solder flows out onto the jet nozzle and flows simultaneously. The solder fills the soldering nozzle from the pipe and overflows, the oxide film on the upper surface flows down, and the solder temperature stabilizes due to fluid circulation. When the jet screw is stopped, the solder inside the jet nozzle is lowered to the same height as the molten solder outside, and the solder inside the introducing pipe and the soldering nozzle stands still at the height of the upper opening of the soldering nozzle.

When the height of the introducing portion is lower than the upper end of the soldering nozzle, the jet screw constantly rotates, and the solder flows out onto the jet nozzle. The solder is still and stable at the upper end opening of the soldering nozzle having the same height as the plane of the solder flowing out. At this time, the flow control plate at the upper edge of the jet nozzle, the flow control valve in the jet nozzle, or the jet screw equipped with the motor in the introduction pipe is operated to raise the solder height in the jet nozzle or flow into the introduction pipe. By increasing the amount of solder to be applied, the solder is caused to flow out from the upper end of the soldering nozzle.

[0016]

EXAMPLES Examples will be described with reference to the drawings.
In FIG. 1, molten solder 2 having a constant temperature is stored in a solder bath 1, and a motor 3 rotates a jet screw 4. The solder in the flow pipe 5 is pushed out and jet nozzle 6
Overflows from the top edge of. At this time, the solder flows into the introduction pipe 7 through the introduction portion 8 provided inside the jet nozzle 6 and lower than the upper surface thereof, and at the same time fills the soldering nozzle 9. Since the upper end of the jet nozzle 6 is higher than the upper end of the soldering nozzle 9, the solder filled in the soldering nozzle 9 overflows, and the oxide film on the surface is also washed off. Next, when the power of the motor 3 is turned off and the rotation of the jet screw 4 is stopped, the solder in the jet nozzle 6 loses the force being pushed up and is lowered to the same height as the solder outside the jet nozzle 6.
Here, by setting the height of the introduction portion 8 on the same horizontal plane as the upper end of the soldering nozzle 9 or at a position slightly higher than that, the solder in the soldering nozzle 9 is kept at a full edge and is in a stationary state. Become. After this, the printed board on which the components are mounted is contacted from above and soldering is performed.

In the embodiment shown in FIG. 2, the introduction pipe 17 is provided outside the jet nozzle 16. Jet nozzle 1
The solder flowing out of 6 flows in from the introducing portion 18 on the upper side or the upper end side of the introducing pipe 17. Since the introduction portion 18 is lower than the upper end of the jet nozzle 16 and higher than the upper end of the soldering nozzle 9, the solder flows out from the soldering nozzle 9. Next, the situation in which the motor 3 is stopped and the board is soldered is the same as in the embodiment shown in FIG.

In the embodiment shown in FIG. 3, the jet nozzle 2
No. 6 continues to flow out the solder, and the solder surface is flat and stable because the upper end opening is sufficiently wide. The introduction pipe 27 is inscribed in the jet nozzle 26, and the opening solder introduction portion 28 is set below the solder surface of the jet nozzle 26. The height of the upper end of the soldering nozzle 9 is the jet nozzle 26.
It is on the same horizontal plane as the solder surface. Therefore, the solder on the soldering nozzle 9 is still and stable at the upper end of the opening. That is, FIG. 3 shows the state of solder at the time of soldering.

In the embodiment shown in FIG. 4, the introducing pipe 37 is provided outside the jet nozzle 36 in the embodiment shown in FIG.

In the embodiment shown in FIG. 5, the flow restricting plate 10 which is movable up and down is provided on a part or all of the upper side surface of the jet nozzle 46 in the embodiment shown in FIGS. As shown in the figure, when the flow restricting plate 10 is raised, the solder overflows from the soldering nozzle 9 to remove the oxide film, and the solder flows to stabilize the temperature. When I lower it again,
Obtain a solderable stationary stable surface.

In the embodiment shown in FIG. 6, the restrictor valve 11 is provided inside the jet nozzle 56 in the embodiment shown in FIGS. 3 and 4, and the solder is prevented from ejecting to the upper end of the jet nozzle 56 by closing the restrictor valve 11. Overflows from the soldering nozzle 9, and when it is opened, the solder flows from the upper end of the jet nozzle 56 to obtain a stationary stable surface that can be soldered.

In the embodiment shown in FIG. 7, the jet screw 14 connected to the motor 13 is installed in the introduction pipe 67 in the embodiment shown in FIGS. Jet screw 14
The force that causes the solder to flow is smaller than that of the jet screw 4. When the jet screw 14 rotates, the solder overflows from the soldering nozzle 9, and when the jet screw 14 stops rotating, a stationary stable surface that can be soldered is obtained.

[0023]

Since the present invention is constructed as described above, it has the following effects.

Since the solder is taken in from the jet nozzle through the introduction pipe, it is not directly affected by the defect of the solder in the jet nozzle, so that the solder plane of the soldering nozzle opening is stable regardless of its size. , Even if it is minute, there is no disturbance.

For the same reason as described above, even if the opening of the soldering nozzle has an arbitrary shape and is freely arranged, it is possible to create a solder plane having the same height.

In any of the mechanisms of the present invention, the soldering nozzle at the time of soldering does not allow the solder to flow down from the upper end thereof, so that the thickness of the solder is not affected.
It also enables extremely small soldering and also allows soldering in which the gaps between the nozzle openings are narrowed.

When the height of the introduction portion is higher than or equal to the upper end of the soldering nozzle, the jet surface screw can be stopped to easily obtain a solder surface on the soldering nozzle, and a small and simple mechanism having few moving parts. This enables a partial soldering device.

When the height of the introducing portion is lower than the upper end of the soldering nozzle, the jet screw always rotates and the solder can flow into the soldering nozzle from the introducing portion at any time. Sufficient solder can be supplied to the mounting location.

The circuit of the printed circuit board can be made finer,
Also, by preventing deterioration of adjacent components that have been previously mounted and soldered due to heating, it is possible to easily and efficiently arrange and solder leaded components and surface-mounted components on the front and back of one board. become. The mounting method in which these two types of components, which are different in soldering method, are mixed, is useful for miniaturization and multifunctional products using printed circuit boards to minimize the volume occupied by the circuit board or maximize the function that can be accommodated within a certain volume. It seems to be.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of a jet solder bath.

FIG. 2 is a vertical cross-sectional view showing an embodiment of a jet nozzle and an introduction pipe.

FIG. 3 is a vertical cross-sectional view showing an embodiment of a jet nozzle and an introduction pipe.

FIG. 4 is a vertical cross-sectional view showing an embodiment of a jet nozzle and an introduction pipe.

FIG. 5 is a vertical sectional view showing an embodiment of a jet nozzle and an introduction pipe.

FIG. 6 is a vertical cross-sectional view showing an embodiment of a jet nozzle and an introduction pipe.

FIG. 7 is a vertical sectional view showing an embodiment of a jet solder bath.

FIG. 8 is a vertical sectional view showing a conventional jet solder bath.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Solder tank 2 Molten solder 3,13 Motor 4,14 Jet screw 5 Flow tube 6,16,26,36,46,56 Jet nozzle 7,17,27,37,47,57,67 Introductory tube 8,18, 28,38 Introductory part 9 Soldering nozzle 10 Flow control plate 11 Flow control valve

Claims (8)

[Claims] 1. A solder bath (1) containing a molten solder (2).
A jet screw (4) having a motor (3) installed therein, a flow pipe (5) inscribed at one end of the jet screw (4) and connected at the other end to a jet nozzle (6), and the jet nozzle ( 6) A partial soldering device using a jet solder bath, in which a soldering nozzle (9) connected to an introduction pipe (7) provided side by side is installed. 2. The introduction pipe (7) is provided in the jet nozzle (6), and the height of the introduction portion (8) of the introduction pipe (7) is equal to or higher than the height of the upper edge of the soldering nozzle (9). 2. The partial soldering device using the jet solder bath according to claim 1. 3. The introduction pipe (17) is provided outside the jet nozzle (16), and the height of the introduction portion (18) of the introduction pipe (17) is equal to or higher than the height of the upper edge of the soldering nozzle (9). Claim 1
Partial soldering device using the described jet solder bath. 4. The introduction pipe (27) is provided in the jet nozzle (26), and the height of the introduction portion (28) of the introduction pipe (27) is lower than the height of the upper edge of the soldering nozzle (9). The partial soldering apparatus according to claim 1, wherein the height of the outflowing solder of the jet nozzle (26) is the same as the height of the upper end of the soldering nozzle (9). 5. The introduction pipe (37) is provided outside the jet nozzle (36), and the height of the introduction portion (38) of the introduction pipe (37) is lower than the height of the upper edge of the soldering nozzle (9). 2. The partial soldering apparatus according to claim 1, wherein the plane height of the solder flowing out of the jet nozzle (36) is the same as the height of the upper end of the soldering nozzle (9). 6. The partial soldering device using a jet solder bath according to claim 4, wherein a flow restricting plate (10) is provided on an upper edge portion of the jet nozzle (46). 7. A flow control valve (11) in the jet nozzle (56).
The partial soldering device using the jet solder bath according to claim 4 or 5, further comprising: 8. A partial soldering apparatus using a jet solder bath according to claim 4, wherein a jet screw (14) having a motor (13) mounted therein is provided in the introduction pipe (67).