JPH0565472U - Automatic soldering equipment - Google Patents

Abstract

(57) [Summary] [Structure] In an automatic soldering device, a solder tank 1, a solder drawing tank 2 having an opening 5 on an upper surface, and a support arm 4 support the drawing tank 2 so that the drawing tank 2 is stopped in the solder tank. Solder blow-out pipe 3a which is connected to the support member in communication with the pumping tank 2 and whose blow ports 6a to 6c are located below the opening 5.
~ 3c and the arm 4 is moved up and down to raise the set of the pumping tank 2 and the blowing pipes 3a to 3c until the outlets 6a to 6c emerge from the solder liquid level L, and the opening 5 is below the solder liquid level. And a board transfer mechanism for carrying the printed circuit board (20) close to the air outlets (6a-6c) when the blow-out tubes (3a-3c) are raised. [Effect] A new type device is provided which is improved with respect to the drawbacks of the pumping-up type soldering method, in which the amount of solder oxide generated is small, the degree of temperature cooling of the solder liquid is small, and the temperature distribution of the solder liquid is uniform. . Selective soldering to a specific portion of the board 20 is possible.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an automatic soldering device, and more particularly to a new type automatic soldering device which is improved on the basis of a conventional pumping-type soldering device and particularly adapted to so-called spot soldering.

[0002]

[Prior Art]

 Conventionally, as one type of automatic soldering of a printed circuit board, there is a pumping type soldering method. This is because a solder tank with an open top is placed in the solder bath in advance, and when soldering, the printed circuit board is carried over the solder tank, and the top of the solder tank is exposed above the solder liquid surface. The soldering method is such that the soldering liquid is pulled up until it is brought into contact with the lower surface of the printed circuit board for soldering, and then the soldering tank is lowered and submerged in the solder bath.

[0003] Such a drawing-up type soldering method generally has poor finished quality of a product, and therefore, until now, other soldering methods such as a jet type soldering method, a dipping type soldering method and a reflow soldering method are widely used. It is not popular.

[0004]

[Problems to be solved by the device]

 The disadvantages of the pump-up type soldering method were due to some drawbacks described below.

The solder liquid in the solder bath vibrates greatly as the solder tank is raised and lowered, and is vigorously stirred. Therefore, since there are many opportunities for air contact, the entire solder liquid in the bath is likely to be oxidized immediately, and the amount of solder oxide generated becomes very large. In this method, since the solder oxide is inevitably formed during the vertical movement operation of the solder tank, and the formed solder oxide is mixed in the solder liquid by stirring, it can be effectively removed to the outside. It's very difficult. Therefore, it was difficult to obtain a completely satisfactory soldering evaluation for soldered products.

Further, the solder liquid is rapidly cooled and easily solidified by being pumped up from the molten solder bath in the solder bath. Moreover, oxides are easily formed by contact with air. Therefore, it is necessary to contact the solder liquid on the upper surface of the tank with the lower surface of the printed circuit board as soon as possible after pulling up the solder tank. Due to the delay in the contact time, soldering defects may occur, and solder oxides and the like often remain on the lower surface of the substrate even if soldering defects do not occur. Therefore, in the soldering equipment, special consideration was required for timing adjustment.

Further, even if the solder tank is repeatedly raised and lowered, only the surface portion of the solder liquid in the tank is replaced with new solder liquid in the solder bath, and the solder liquid in the deep layer portion in the tank is hardly replaced. , The almost same component liquid remains. Therefore, the heat generated by the heater at the bottom of the bath is not evenly transmitted to the entire interior of the solder bath including the solder tank, so the temperature of the solder liquid in the solder bath has a certain level difference in some places, and the temperature distribution is very poor. .. The non-uniform temperature distribution makes it difficult to control the temperature of the solder liquid that comes into contact with the printed circuit board, and as a result, defective soldered products are likely to occur.

Therefore, in order to further popularize and develop the pumping-up type soldering method, it has been necessary to make some improvements in regard to the above defects.

By the way, recently, with the progress of high integration and miniaturization of electronic components, integrated components such as flat packages and chip components have become extremely high in density together with lead wire components (per substrate). The demand for printed circuit board products that are configured to have nearly 100 or about 400 components) is increasing. This product usually consists of a flat package, lead wire components, etc. on the front side of the board, and chip components on the back side of the board.

Conventionally, automatic soldering of such a high-density mixed-type board product has been performed mainly by a reflow soldering method. However, the reflow soldering method is not suitable for soldering lead wire components such as large capacitors, and automatic soldering cannot be completed only by this method. In other words, it has been desired to develop a technique capable of selectively soldering a predetermined portion of the printed circuit board, particularly a device for selective soldering.

The present invention has been made in view of such circumstances, and its purpose is to build on a conventional pump-up type soldering method, but to improve its drawbacks by using a completely new automatic method. It is to provide a soldering device.

Another object of the present invention is to enable selective patterning of a predetermined part in a printed circuit board, so that lead wire parts and chip parts can be mixedly mounted on both sides of the board with high density. It is an object of the present invention to provide a so-called spot soldering device that can advantageously perform automatic soldering to a printed circuit board that has been printed.

[0013]

[Means for Solving the Problems]

 According to the present invention, the assembly of the tank and the blow-out pipe, both of which has an open upper surface and communicates with each other, is housed in the solder bath, and is moved up and down to be positioned below the opening on the upper surface of the tank when rising. It is intended to provide a new automatic soldering technique in which a new solder liquid is continuously spilled through an upper opening of a blow-out pipe, and a printed circuit board is brought into contact with the overflowing solder liquid to perform soldering.

That is, in the automatic soldering device according to the present invention, a solder bath, a solder pumping tank having an opening on the upper surface, and a support arm are attached to the solder pumping tank so that the tank stops in the solder bath. A supporting member for supporting the solder pumping tank, a solder blowing pipe connected to the solder drawing tank so as to communicate with the inside of the tank, and a blow port on the upper surface of the pipe located below the opening on the upper surface of the tank; An elevating means that elevates and lowers the solder pumping tank and the solder blow-out pipe until the blow-out port comes out of the solder liquid surface when rising, and lowers when the opening is submerged below the solder liquid surface, and the solder blow-out pipe. It is equipped with a board transfer mechanism that moves the printed circuit board close to the outlet of the solder blow-out tube when the temperature rises.

A preferred embodiment of the present invention is the above automatic soldering apparatus with the addition of the following elements (i) to (iii). (i) A device in which the blow-out port of the solder blow-out tube is a blow-out port that can selectively come close to a predetermined portion of the printed circuit board to be soldered. (ii) A device in which a plurality of solder blow-out pipes are connected to a solder pumping tank using an assembling plate so that the blow-out ports are located on the same plane. (iii) A device in which a solder blowing pipe is detachably connected to a solder drawing tank.

Further, another preferred aspect of the present invention is, in all of the above automatic soldering apparatuses, including the apparatus to which the above-mentioned elements (i) to (iii) are added, further including a surface layer in the solder bath. It is provided with a surface flow forming means for sending the solder liquid from one wall side of the solder bath to the opposite other wall side of the bath.

In a particularly preferred embodiment of this type of apparatus, the solder bath constitutes a double bath composed of an inner bath for accommodating the solder pumping tank and the solder blowing pipe and an outer bath outside thereof, and a surface As a flow forming means, the solder liquid is poured from one wall side of the solder inner tank, the solder liquid overflows from the other wall on the opposite side of the solder inner tank, and then flows into the gap passage between the inner tank and the outer tank. It is equipped with a solder liquid circulation system that collects on one wall side of the solder inner tank.

Hereinafter, each component of the present invention will be described.

The solder tank may be a tank having a volume capable of accommodating an assembly of the solder drawing tank and the solder blowing pipe, and preferably comprises an inner tank accommodating the assembly and an outer tank outside thereof. It constitutes a double tank. In this case, the heater for heating the solder is preferably arranged in the gap passage between the inner tank and the outer tank from the viewpoint of maintaining the solder in a favorable molten state.

The solder drawing tank is a tank having a relatively large capacity having an opening on the upper surface, and its shape is not limited. The opening on the upper surface of the tank is located above the outlet of the solder blowing pipe. The shape and number of the openings are not limited in any way.

The support member may be a member that attaches the support arm to the solder drawing tank and supports the tank so as to be stopped in the half-tank tank.

The solder blowing pipe is connected to the solder drawing tank so as to communicate with the inside of the tank. The blow-out pipe may have a shape having a blow-out port on the upper surface of the pipe, and may be a substantially straight pipe or a complicatedly bent pipe. In a more preferable embodiment, the solder blowing pipe is detachably connected to the solder drawing tank.

Further, the solder blow-out pipe is connected so that the blow-out port on the upper surface is located below the opening on the upper surface of the solder drawing tank. The difference in height between the upper surface opening of the solder pumping tank and the outlet of the solder outlet pipe determines the force of the solder liquid overflowing from the outlet of the solder outlet pipe. In addition, the volume of the portion of the solder pumping tank that is above the height of the outlet of the solder outlet pipe determines the total amount of the solder liquid overflowing from the outlet of the solder outlet pipe.

Further, the outlet of the solder outlet tube may be an outlet having a size corresponding to the entire lower surface of the printed circuit board to be soldered, but since it enables selective soldering, It may be a blow-out port having a size corresponding to a predetermined portion of the above.

In particular, in order to perform selective soldering at a plurality of locations, when connecting a plurality of solder blow-out pipes to a solder pumping tank, an assembly plate is used, and a solder blow-out pipe is attached to this. Collectively, it is preferable to assemble them so that the respective blow ports are located on the same plane. The assembly plate may have a structure in which a plurality of holes, through which a solder blowing tube can be inserted and fixed, are formed on the surface of the plate so that the assembly plate can be connected to the solder drawing tank.

The elevating means is provided with a drive mechanism for elevating the support arm of the support member, and the assembly of the solder drawing tank and the solder blowing tube is exposed from the solder liquid surface when the nozzle of the solder blowing tube is exposed. It is possible to use any means that can raise the temperature until the temperature rises, and when lowering, lowers the opening of the solder-pumping tank until it sinks below the surface of the tank. Examples of the raising / lowering means include those equipped with an air cylinder, a motor or the like, and vertically moving the support arm by its driving force. Besides, various concrete configurations of the present means are conceivable, but the present invention includes all of them.

The board transport mechanism conveys the printed circuit board so as to be close to the outlet of the solder blow-out pipe when the solder blow-out pipe rises, and expediently prints when the solder blow-out pipe descends. Any mechanism may be used as long as it can move the circuit board away from the outlet of the solder blowing tube. Although there are various types and embodiments of the mechanism that enables such conveyance, the present invention includes all of these types and embodiments.

The surface flow forming means may be any means capable of sending the solder liquid of the surface layer in the solder bath from one wall side of the solder bath to the other wall side facing the bath, for example, By pouring the solder solution from the supply port on one wall side of the solder bath using a pump, etc., the solder solution on the surface layer in the bath flows from one wall side to the other wall on the opposite side, and then the solder bath One example is one that overflows from the other wall.

Finally, in addition to the surface flow forming means, the solder liquid circulation system collects the solder liquid overflowing from the other wall side of the solder bath, and keeps the molten state on the one wall side of the solder bath. Any structure that can be returned and reused may be used. From the viewpoint that the molten state can be easily maintained, it is preferable to return the solder solution collected on the other wall side to the one wall side by flowing it into the gap passage between the inner tank and the outer tank of the double solder tank. ..

In addition to the above-described solder bath, the automatic soldering device to which the present invention is applied has a foam flux bath, a preheater, and if necessary, a cooling fan, etc., which are sequentially arranged at predetermined positions through a conventional device. May be configured as a device. Either a so-called carrier type or a carrierless type may be used.

[0031]

[Action]

 In the automatic soldering apparatus of the present invention, the set of the solder pumping tank and the solder blowing tube is supported by the supporting member so as to be stopped in the solder bath, and is lifted together with their supporting arms. When it moves up and down and rises, it rises until the outlet of the solder blow-out pipe emerges from the solder liquid surface, and when it descends, it descends until the opening on the upper surface of the pumping tank submerges below the solder liquid surface.

In the present invention, the outlet of the solder blowing pipe is located below the opening of the solder drawing tank, and there is a constant height difference between the outlet and the opening. Therefore, during the ascending process of the combination of the tank and the blow-out pipe, whether the volume of the solder liquid in the upper part of the solder pumping tank is higher than the height of the blow-out port when the opening on the top surface of the tank emerges from the solder liquid surface. From the inside of the tank, through the communication port, into the solder blow-out pipe, and then overflow from the blow-out port.

Then, when the outlet of the solder outlet tube is exposed from the surface of the solder liquid and the solder liquid is overflowing from the outlet, the printed circuit board is brought close to the outlet by the substrate transfer mechanism and the lower surface of the substrate is removed. Soldering can be performed by contacting the overflowing solder solution.

In this case, until there is no difference between the height of the solder liquid in the solder pumping tank and the height of the solder liquid in the solder blowing pipe (that is, the height of the blowing port), the solder liquid continues to overflow from the blowing port. .. In other words, new solder liquid can be continuously supplied from the inside of the solder pumping tank to the outlet of the solder outlet pipe until there is no difference in the height of the solder liquid.

After the completion of soldering, the pair of the solder drawing tank and the solder blowing tube is lowered by the elevating means, and the opening on the upper surface of the tank is submerged below the solder liquid surface. As a result, another new solder solution is replenished from the inside of the solder bath through the opening into the solder drawing tank.

As described above, the inside of the solder pumping tank is always replaced with a new solder liquid, and the replaced solder liquid is sequentially sent to the solder outlet pipe, and then overflows from the outlet to be used for soldering. It

Therefore, in the device of the present invention, since the solder liquid used for soldering is continuously supplied from the inside of the solder blowing pipe, the degree of cooling of the solder liquid by air is smaller than the conventional one. In addition, the smooth replacement of the solder liquid makes the temperature distribution of the solder liquid uniform throughout the solder bath.

The above operation is in contrast to the conventional pump-up type soldering device in which the solder liquid in the deep layer portion in the tank is hardly exchanged.

Further, in the present invention, the arrangement, shape and size of the outlet of the solder blow-out pipe are set so that the outlet can come into close contact with only a predetermined portion of the printed circuit board to be soldered. This enables selective soldering.

In particular, if a means for fixing each of the plurality of solder blow-out pipes so that the respective blow-out ports are located on the same plane by using the assembly plate is adopted, it is possible to obtain uniform pressure from any of the blow-out ports. Then, the solder solution overflows, so that selective soldering at a plurality of locations can be properly performed.

Further, by detachably connecting the solder blow-out pipe, the solder blow-out pipe can be replaced. Therefore, the arrangement, shape and size of the blow-out port of the solder blow-out pipe can be changed according to the type and model of the substrate to be soldered. Corresponding changes are easy to make.

Further, by providing the surface flow forming means for sending the solder liquid of the surface layer in the solder bath from the one wall side of the solder bath to the opposite other wall side of the bath, it is formed on the surface of the solder liquid anyway. It becomes possible to effectively remove easy-to-use solder oxides during operation, which in turn contributes to improved soldering performance.

In particular, since the solder bath is a double bath and the above-mentioned solder liquid circulation system is provided, the action of removing the solder oxide becomes more efficient, and further, the device can be downsized, and indeed It will be excellent.

[0044]

【Example】

 The present invention will be described below with reference to the embodiments shown in the drawings. As shown in FIGS. 1 to 3, the automatic soldering apparatus of the embodiment accommodates a solder tank 1 and a solder pumping tank 2 and three solder blow-out tubes 3a, 3b, 3c connected in communication therewith. I will do it.

The solder bath 1 constitutes a double bath composed of an inner bath 11 for accommodating these sets and an outer bath 12 outside thereof, and a heater 16 for solder heating is provided with a solder inner bath 11 and a solder outer bath. It is arranged in the gap passage 15 between the two.

The solder drawing tank 2 is a tank having an equivalent capacity having an opening 5 on the upper surface, and a supporting arm 4 is attached to the solder drawing tank 2 by means of a supporting member (the base side of the arm 4 is not shown). It is supported so that it stops in 1.

As clearly shown in FIG. 4, the solder blow-out pipes 3 a to 3 c are bent pipes and communicate with the solder drawing tank 2, respectively. The solder blowing tubes 3a to 3c are detachably connected to the solder drawing tank 2.

Each of the blow-out pipes 3 a to 3 c has blow-out ports 6 a, 6 b, 6 c on the pipe upper surface, and these blow-out ports 6 a to 6 c are located below the opening 5 on the upper surface of the solder drawing tank 2. To do. In the figure, h indicates the difference in height between the blower openings 6a to 6c and the opening 5.

Then, using the assembly plate 7, the solder blow-out pipes 3a to 3c are inserted and fixed in the holes 19 ... of the plate surface, so that the blow-out ports 6a to 6c are located on the same plane. They are assembled together (see Fig. 4).

Further, in the apparatus of the embodiment, the support arm 4 is moved up and down (± y direction in the figure) by the elevating means (not shown) to assemble the solder pumping tank 2 and the solder blowing tubes 3a to 3c. Can be raised until the blowout ports 6a to 6c emerge from the solder liquid level L when ascending, and can be lowered when descending until the opening 5 on the tank upper surface is submerged below the solder liquid level. ..

Further, the apparatus of the embodiment is provided with the solder liquid circulation system 10 as a means for sending the solder liquid of the surface layer in the solder inner bath 11 from the one wall side of the bath to the opposite wall side. There is.

That is, the blade 14 is rotatably provided on one wall side of the tank, and the blade 13 is rotated by the operation of the motor 13 connected thereto, sucking the solder solution from the port 17 and soldering on the one wall side of the tank. It is poured from the inlet 8 into the solder inner tank 11 so that the half bath liquid of the surface layer in the tank flows from one wall side of the tank to the other wall side of the tank as shown by an arrow x in FIG. And, it is designed to overflow from the other wall 9 of the half-tanai tank 11. Then, the solder liquid overflowing from the other wall 9 flows into the gap passage 15 between the inner solder bath 11 and the outer solder bath 12 as shown by an arrow f in FIG. 1, and is collected on one wall side of the bath. After that, it is supplied again to the solder injection port 8.

Finally, although not shown, the apparatus of the present embodiment is arranged so that the printed circuit board 20 is brought close to the outlets 6a to 6c of the outlet pipes 3a to 3c at the time when the solder outlet pipes 3a to 3c rise. And a board transfer mechanism that moves the printed circuit board 20 away from the outlets 6a to 6c of the outlet tubes 3a to 3c when the solder outlet tubes 3a to 3c descend (see FIG. 3). ..

Further, in the automatic soldering apparatus of the embodiment, in addition to the solder bath 1 described above, a foam flux bath, a preheater, and if necessary, a cooling fan and other devices having a conventional configuration are sequentially placed at predetermined positions. The printed circuit boards are arranged and arranged, and the printed circuit boards are transported in a so-called carrier type or carrierless type according to the arrangement order, and each step of soldering can be automatically performed.

Next, how to use the apparatus of the embodiment will be described.

(I) First, the set of the solder drawing tank 2 and the solder blowing tubes 3a to 3c is made to stand by at a position where it is submerged below the solder liquid surface as shown in FIG. At this stage, the blades 14 are rotated so that the solder solution is poured into the solder inner tank 11 through the injection port 8, and the solder solution flows from one wall side to the other wall side in the tank (arrow x ) Is formed, and the solder liquid overflowing from the other wall 9 is collected to the one wall side through the gap passage 15 (arrow f).

By constantly circulating such a solder solution during operation, the solder oxide could be effectively removed from the surface of the solder solution.

(Ii) Next, by operating the elevating means, the set of the solder drawing tank 2 and the solder blowing tubes 3a to 3c is pulled up (arrow + y) as shown in FIG. 2, and the opening of the drawing tank 2 is opened. 5. Then, the outlets 6a to 6c of the outlet pipes 3a to 3c are exposed from the solder liquid level L.

Then, since there is a difference in height h between the opening 5 and the outlets 6a to 6c, the solder liquid in the solder pumping tank 2 flows into the respective solder outlet tubes 3a to 3c as shown by an arrow p. It flows and then overflows from the outlets 6a to 6c.

The momentum of the solder liquid overflowing from the outlets 6a to 6c of the solder outlet pipes 3a to 3c is initially due to the difference in height h between the opening 5 of the solder drawing tank 2 and the outlets 6a to 6c. And thereafter, it is determined by the height difference h ′ between the solder liquid level in the tank 2 and the outlets 6a to 6c.

Further, the total amount of the solder liquid overflowing from the outlets 6a to 6c is determined by the volume of the portion of the solder drawing tank 2 above the outlets 6a to 6c of the outlet pipes 3a to 3c. It

(Iii) Then, at the time when the solder liquid overflows from the blowout ports 6a to 6c, the printed circuit board 20 is blown from above the blowout ports 6a to 6c by the operation of the substrate transfer mechanism, as shown in FIG. 6c, and the lower surface of the substrate 20 is brought into contact with the overflowing solder solution to carry out soldering.

(Iv) After the completion of soldering, the lifting and lowering means lowers and lowers the set of the solder pumping tank and the solder blowing tube, and at the position where the opening 5 on the tank upper surface is submerged below the solder liquid level L, Wait until soldering. At this time, another new solder liquid is supplied from the solder inner tank 1 through the opening 5 into the solder drawing tank 2.

In this way, the inside of the solder drawing tank 2 is always replaced with a new solder solution, and the replaced solder solution is then used at the next or subsequent soldering occasions to the solder blow-off pipes 3a to 3c. And then overflows from the air outlets 6a to 6c to be used for soldering.

Therefore, in the apparatus of the embodiment, since the solder liquid is continuously supplied from the inside of the solder blow-out pipes 3a to 3c to the outlets 6a to 6c, the degree of cooling of the solder liquid is small, and the solder liquid is small. The temperature distribution of was also uniform over the entire solder bath.

[0066]

[Effect of the device]

 As can be seen from the above description, according to the present invention, the drawbacks of the conventional pumping-up type soldering method are improved, and the generation amount of solder oxide is significantly smaller than that of the conventional soldering apparatus of that kind. In addition, a completely new method of automatic soldering device is characterized in that the degree of cooling of the temperature of the solder solution until contact with the printed circuit board is small and the temperature distribution of the solder solution is uniform over the entire solder bath. Will be provided.

Further, as a more preferable embodiment of the present invention, if the outlet of the solder blow-out tube is close to only a predetermined portion of the printed circuit board, it is possible to select a specific portion in the printed circuit board. Soldering becomes possible.

In particular, if a plurality of outlets are fixed on the same plane by using an assembling plate, selective soldering at a plurality of locations can be performed well. Also, if the solder blow-out pipe is detachably connected, the solder blow-out pipe can be replaced, and the position, shape and dimensions of the blow-out port can be easily changed according to the type and model of the board to be soldered. Becomes

Therefore, by adopting such an aspect, a very good spot soldering device is provided, and therefore, the device is used to print a configuration in which lead wire components and chip components are mixedly mounted on both surfaces of a substrate at high density. Advantageously, automatic soldering can be performed on the circuit board.

Further, if a means for sending the solder liquid of the surface layer in the solder bath from the one wall side to the other wall side of the solder bath is provided, the solder oxide on the surface of the solder liquid during the operation of the apparatus can be prevented. Effective removal is possible, and therefore high quality soldered products can be obtained.

In particular, if a double solder bath is used and the solder liquid is circulated in the bath, the effect of removing the solder oxide is further enhanced, and the device can be downsized.

[Brief description of drawings]

FIG. 1 is a sectional view showing an automatic soldering device according to an embodiment of the present invention in a standby position.

FIG. 2 is a cross-sectional view showing an automatic soldering apparatus according to an embodiment of the present invention in a rising process.

FIG. 3 is a sectional view showing an automatic soldering device according to an embodiment of the present invention in a soldering position.

FIG. 4 is a perspective view showing a main part of the automatic soldering device according to the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Solder tank 2 Solder pumping tank 3a, 3b, 3c Solder blow-out pipe 4 Support arm 5 Openings 6a, 6b, 6c Blowout port 7 Assembly plate 8 Solder injection port 9 Other wall 10 Solder liquid circulation system 11 Solder inner bath 12 Solder Outer tank 13 Motor 14 Blade 15 Gap passage 16 Heater 18 Overflowing solder liquid 20 Printed circuit board x Flow direction of solder surface flow f Flow direction of solder recovery flow ± y Vertical movement direction h Height of opening and blowout port Difference h'Difference in height between the solder liquid level in the tank and the nozzle mouth p p Flow direction of the solder in the outlet pipe

Claims (6)

[Scope of utility model registration request] 1. A solder bath, a solder pumping tank having an opening on an upper surface, a support member attached to the solder pumping tank so as to support the tank so as to stop in the solder bath, and a solder pumping tank. A solder blowing pipe that is connected to the inside of the tank and is connected so that the nozzle on the upper surface of the pipe is located below the opening on the upper surface of the tank; An elevating device that raises the blow-out pipe until the blow-out port comes out of the solder liquid level when rising, and lowers it when the opening is submerged below the solder liquid level when descending, and a printed circuit board at the time when the solder blow-out pipe rises. An automatic soldering device comprising a substrate transfer mechanism that conveys the solder so as to be close to the outlet of the solder discharge tube. 2. The apparatus according to claim 1, wherein the outlet of the solder outlet tube is an outlet capable of selectively approaching a predetermined portion of the printed circuit board to be soldered. 3. The apparatus according to claim 1, wherein a plurality of solder blow-out pipes are connected to the solder drawing tank using an assembling plate so that the blow-out holes are located on the same plane. . 4. The apparatus according to claim 1, wherein the solder blowing pipe is detachably connected to the solder drawing tank. 5. The surface flow forming means for sending the solder liquid of the surface layer in the solder bath from the one wall side of the solder bath to the opposite other wall side of the bath. 4. The device according to claim 4. 6. The solder bath comprises a double bath composed of an inner bath for accommodating a solder drawing tank and a solder blowing pipe and an outer bath outside the solder bath, and the solder liquid is used as a surface flow forming means. Solder solution that pours from one wall of the solder, overflows the solder solution from the other wall on the opposite side of the solder inner tank, and flows into the gap passage between the inner tank and the outer tank to collect on the one wall side of the inner solder tank. The apparatus of claim 5, comprising a circulation system.