JPH0742598U - Inert gas atmosphere forming device for soldering equipment - Google Patents

Abstract

(57) [Summary] [Purpose] To reduce the cost of soldering equipment that holds an inert gas atmosphere and to prevent the oxidation of the solder melt to suppress lead pollution. [Structure] A chamber 7 for holding an inert gas atmosphere is provided in a region of a solder bath 3 for soldering a wiring substrate 1 with a solder melt 4, and an inert gas is supplied to an outlet 9 side of the chamber 7 to be rotatable. The nozzle 14 and the inert gas supply chamber 12 provided with the rotatable U-shaped mouth casing 13 for adjusting the supply of the inert gas by providing the nozzle 14 therein, and also in the chamber 7. It is characterized in that a plurality of suppressing plates 15 for suppressing the flow of the inert gas are provided in the region of the solder bath 3.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a gas atmosphere forming device for a soldering device that forms an inert gas atmosphere of low oxygen concentration only in the soldering process environment near the solder bath. It has a high sealing property.

[0002]

[Prior art]

As an apparatus for soldering in an atmosphere of an inert gas such as nitrogen (N ₂ ), for example, as described in Japanese Patent Application No. 4-353879 filed by the present applicant, a preliminary heating device and a solder bath are used. There is a configuration in which the tunnel-shaped chamber is covered with a tunnel-shaped chamber, and the tunnel-shaped chamber is extended along the transfer path of the wiring board. On the inner surfaces of the lower and upper sides of the chamber, a plurality of partition plates are provided in a direction intersecting with the transfer direction of the wiring board and toward the transfer path of the wiring board, and a so-called labyrinth flow path is provided. Is forming.

In this labyrinth flow passage, since the tunnel-shaped chamber forms a pipe, the flow resistance determined by the cross-sectional area and length of the pipe and the flow resistance specific to the labyrinth flow passage have. Therefore, it becomes difficult for the inert gas supplied into the chamber to flow out of the chamber, and it becomes difficult for the atmosphere outside the chamber to flow into the chamber. As a result, it is possible to maintain the environment of the soldering process in the chamber in an inert gas atmosphere having a low oxygen concentration.

Further, the above-mentioned application discloses that the supply position of the inert gas and the supply / jet direction of the inert gas are important, and that these optimum technologies are realized as a unique chamber structure. .

That is, a nozzle that supplies an inert gas is provided at a position rearward from the position where the soldering of the wiring board is completed in the transport direction of the wiring board, and at that time, the nozzle forms a labyrinth passage. The configuration is such that it is provided between a plurality of partition plates, and the direction in which the inert gas is ejected from between the partition plates toward the transport path of the wiring board is opposite to the transport direction of the wiring board. There is.

By the way, as the wiring board is transported, the atmosphere in the chamber flows in the direction in which the wiring board, the transport conveyor, or the carrier on which the wiring board is mounted is attracted in the traveling direction and pulled out of the chamber. . Therefore, the jetting direction of the inert gas is configured to be opposite to the transporting direction of the wiring board, so that the atmosphere flow in such an outflow direction is suppressed and the atmosphere sealing property is improved. There is.

Further, the development of so-called non-cleaning flux, water-soluble flux, etc. has progressed rapidly, and flux with very few residues after soldering, flux that can be easily washed with water, or residues after soldering The flux that turns into a polymer resin film has reached the stage of practical use, and by maintaining only the soldering process in an inert gas atmosphere with a low oxygen concentration, CFC cleaning of the wiring board can be performed while maintaining good soldering characteristics. It is becoming unnecessary.

[0008]

[Problems to be solved by the device]

 By the way, the purpose of soldering in an inert gas atmosphere of low oxygen concentration is to ensure good soldering characteristics with a small amount of flux, and there is no need to wash the wiring board after soldering work. This is also because the surface tension of the solder melt is lowered, so that an essential environment for realizing so-called micro soldering can be obtained.

In order to realize such an environment of the soldering process, it is most desirable to place the entire process of heating the wiring board in an inert gas atmosphere, as is apparent from the technical idea of the prior art. That is, it is desirable to maintain the atmosphere in an inert gas having a low oxygen concentration, including the preheating step and the soldering step.

However, making the soldering apparatus in an inert gas atmosphere with a low oxygen concentration as described above requires a large-scale chamber, which increases the parts and manufacturing cost of the soldering apparatus and increases the apparatus price. It will make you soar. In other words, in order to realize the soldering process in an inert gas atmosphere, it was necessary to discard the conventionally used soldering equipment and newly invest a large amount of capital. .

On the other hand, a soldering device that performs soldering in the atmosphere has a low apparatus price, but there is a problem that lead is diffused into the atmosphere when the solder melt is oxidized and causes lead pollution. there were.

The present invention has been made to solve the above-mentioned problems, and a chamber having a high sealing property is provided in a region in which a solder melt of a solder bath is used to solder a wiring substrate, and a chamber having a high sealing property is provided. By maintaining the atmosphere, it is aimed to reduce the cost of the soldering equipment and to obtain an inert gas atmosphere forming equipment for the soldering equipment that prevents the oxidation of the solder melt and suppresses the occurrence of lead pollution. .

[0013]

[Means for Solving the Problems]

 The apparatus for forming an inert gas atmosphere of a soldering apparatus according to the present invention is provided with an inert gas supply chamber for supplying an inert gas into the chamber on the outlet side of the chamber, and the inert gas supply chamber is provided in the inert gas supply chamber. Mouth casings with a U-shaped cross section that project toward the transport conveyor in a direction intersecting the transport direction of the wiring board on the upper side and the lower side of the chamber with respect to the transport conveyor make the opening direction rotatable. And a nozzle for ejecting the inert gas is provided inside the mouth casing, and further, in a direction intersecting the transport direction of the wiring board on the upper inner wall of the region of the solder bath in the chamber. The plate surfaces are arranged side by side, and a plurality of restraining plates are arranged side by side in a direction projecting toward the conveyor.

Further, the restraint plate provided in the area of the solder bath is rotatably provided.

Further, in the chamber, at least one of an inlet and an outlet thereof has plate surfaces arranged in a direction intersecting with a carrying direction of the wiring board, and a plurality of inhibiting plates arranged in parallel in a direction projecting toward the carrying conveyor. It was done.

Further, the chamber is formed so as to be divided into an upper chamber and a lower chamber with respect to the transfer conveyor.

[0017]

[Action]

 In the present invention, the inert gas is ejected from the nozzle of the mouth casing in the inert gas supply chamber in the direction opposite to the direction of transport of the wiring board, and the suppression plate provided in the solder tank area prevents the inert gas atmosphere in the solder tank area. The sealing property can be improved.

Further, since the restraint plate in the solder bath area is rotatable, the flow state of the inert gas atmosphere in the chamber can be adjusted to an optimum state.

Further, since the so-called labyrinth flow path is formed because the suppression plates are arranged in parallel at the inlet or outlet of the chamber, the outflow of the inert gas in the chamber and the inflow of the outside air into the chamber. Can be suppressed.

Further, the chamber is divided into the upper chamber and the lower chamber, so that the chamber can be easily installed and maintained.

[0021]

【Example】

FIG. 1 is a side sectional view showing a first embodiment of the present invention, showing only a solder bath portion of a soldering device and omitting a preheating device and a flux device. In this figure, 1 is a wiring board, 2 is a conveyor for carrying the wiring board 1 in the direction of arrow A, 3 is a solder bath, in which a solder melt 4 is stored, and a primary jet for jetting the solder melt 4 A tank 5 and a secondary jet tank 6 are provided. It should be noted that the impeller for jetting the solder melt 4, the pressure device such as a motor, the heater for heating, etc. are not shown. Reference numeral 7 denotes a chamber, which holds the region of the solder bath 3 in an atmosphere of low oxygen concentration by an inert gas such as nitrogen (N ₂ ) and comprises an upper chamber 7A and a lower chamber 7B. An entrance 8 and an exit 9 through which the conveyor 2 penetrates and the wiring board 1 is loaded and unloaded are formed. Reference numeral 10 denotes a skirt portion for sealing the liquid surface of the solder melt 4 and maintaining the chamber 7 in an inert gas atmosphere, which is immersed in the solder melt 4. Reference numeral 11 denotes a plurality of restraining plates, which are fixed to the upper chamber 7A and the lower chamber 7B on the inlet 8 side of the chamber 7, and which form labyrinth passages, and which are made of plate-shaped members. The plate surfaces are arranged in a direction intersecting the transport direction (arrow A direction), and are provided in a direction projecting toward the transport conveyor 2. Reference numeral 12 is an inert gas supply chamber formed on the outlet 9 side of the chamber 7. The cross section for supplying the inert gas is U-shaped, and the mouth casing 13 having one opening is the upper chamber 7A of the chamber 7. And the outside of the lower chamber 7B on the side opposite to the opening is provided in close contact with the wall of the lower chamber 7B. Reference numeral 14 denotes a nozzle provided in the mouth casing 13, which is formed by a pipe and ejects an inert gas. The mouth casing 13 and the nozzle 14 are separately centered on the same axis, as will be described later in detail. It is rotatable. Reference numeral 15 denotes a rotatable restraining plate provided in the upper chamber 7A at a predetermined interval in the region of the solder bath 3, and is composed of a plate-shaped member, and is in the conveying direction of the wiring board 1 (direction of arrow A). Plates are provided side by side in the direction intersecting with. Reference numeral 16 denotes a rotating shaft, which is formed integrally with the restraining plate 15 and is rotatably supported on the wall surface of the upper chamber 7A.

Although FIG. 1 shows an example in which the primary jet tank 5 and the secondary jet tank 6 are provided in the solder bath 3, one of the primary jet tank 5 and the secondary jet tank 6 is provided. , Or even a flow dip tank only. Further, the conveyor 2 may be of carrierless type or carrier type.

FIG. 2 is a cross-sectional view taken along the line I-I of FIG. 1, and FIG. 3 is a perspective view showing the details of the mouth casing 13 of FIG. 1 in an enlarged manner. Of the four mouth casings 13 illustrated in FIG. Show one. In these figures, the same symbols as in FIG. 1 indicate the same parts. Note that FIG. 2 shows, as an example, a carrier device 18 equipped with a carrierless carrier conveyor 2 having a holding claw 17 for the wiring board 1. That is, the chamber 7 has a structure that can be divided into an upper chamber 7A and a lower chamber 7B with the transport conveyor 2 interposed therebetween, and is for a mouth case through which a hollow mouth case support shaft 21 fixed to the mouth case 13 is inserted. Bearings 22 are fixed to the upper chamber 7A and the lower chamber 7B, respectively. The mouth housing bearing 22 is provided with a fixing screw 23 with a knob for fixing the mouth housing support shaft 21 after adjusting the rotating direction of the mouth housing 13.

The mouth casing 13 has a U-shaped cross section, that is, an opening shape is rectangular, and the longitudinal direction of the opening 24 is arranged in the direction of arrow A intersecting the conveyor 2 and in the direction of arrow A. It is of structure. Further, as can be seen from FIG. 3, the mouth casing 13 has a U-shaped vertical cross section, and a pipe-shaped nozzle 14 for supplying an inert gas is provided at the bottom of the mouth casing 13, The ejection hole 25 for ejecting the active gas is formed. The nozzle 14 has a structure in which the hollow shaft support shaft 21 is inserted and held. The support shaft 21 for the mouth casing is provided with a fixed screw 26 with a knob for adjusting and fixing the rotating direction of the nozzle 14.

In addition, in order to facilitate the assembly of the mouth casing 13 into the chamber 7, the mouth casing support shaft 21 is screwed in to be fixed to the mouth casing 13, or the flange is provided with a screw or a nut. It is advisable to fix from the opening 24 side. It is preferable that the mouth housing bearing 22 can be attached to the chamber 7 in the same manner.

FIG. 4 is a perspective view showing a rotation mechanism of the restraint plate 15 of FIG. 1, and the same reference numerals as those in FIG. 1 denote the same parts, and the rotation shaft 16 to which the restraint plate 15 is fixed is provided in the upper chamber 7A. The bearing 27 is rotatably supported, and the rotating shaft 16 is in close contact with the inner surface of the upper wall of the upper chamber 7A. On the other hand, the rotating shaft 16 and the restraining plate 15 are changed / adjusted in their directions by rotating an operation lever 28 formed by bending a portion of the rotating shaft 16 extending in the longitudinal direction. can do. The bearing 27 of the restraint plate 15 is provided with a fixing screw 29 with a knob for fixing after adjusting the directions of the rotary shaft 16 and the restraint plate 15. At the time of assembly, for example, after inserting the rotary shaft 16 into the bearing 27, the restraining plate 15 may be fixed to the rotary shaft 16 with screws or the like (not shown).

Next, the operation will be described.

FIG. 1 shows a first adjustment example of the restraint plate 15 and the mouth casing 13.

That is, the four mouth casings 13 are oriented symmetrically in the vertical direction toward the solder bath 3 side which is the opposite direction to the transport direction of the wiring substrate 1 (direction of arrow A), and the respective directions are also aligned. On the other hand, two rotatable restraining plates 15 on the inlet 8 side are oriented in a direction perpendicular to the transport direction of the wiring board 1 (arrow A direction), and the other four are slightly oriented on the inlet 8 side. It is adjusted to face.

By adjusting as described above, the inert gas ejected from the mouth casing 13 forms a laminar flow that flows along the transport conveyor 2 in the direction opposite to the transport direction (direction of arrow A), and the secondary flow An inert gas atmosphere having a low oxygen concentration is formed in a region which reaches the primary jet tank 5 from the jet tank 6 and where the wiring substrate 1 and the solder melt 4 are in contact with each other. The laminar flow of the inert gas flowing from the primary jet tank 5 to the inlet 8 side is decelerated by the two vertical stop plates 15 and further forms the labyrinth passage on the inlet 8 side. It is sealed by the restraining plate 11 that prevents the inert gas from flowing out of the chamber 7 and the outside air from flowing into the chamber 7.

When the transport speed of the transport conveyor 2 is further increased, the direction of the mouth casing 13 may be further rotated to adjust the direction toward the solder bath 3 inside the chamber 7. It is possible to suppress the drawing of the atmosphere of the inert gas by the transport conveyor 2 and the wiring board 1 to achieve equilibrium, and to maintain the sealing property of the inert gas atmosphere at a high level.

The optimal direction of the mouth casing 13 and the optimal direction of the suppressing plate 15 are also determined by the amount and the velocity of the inert gas ejected from the nozzle 14, and the amount and the velocity of the inert gas ejected from the mouth casing 13. Also changes. In short, while forming an inert gas atmosphere having a low oxygen concentration in the area where the solder melt 4 contacts the wiring board 1, the amount of the inert gas atmosphere inside the chamber 7 flowing out of the chamber 7 and the outside of the chamber 7 It suffices to find an equilibrium point at which the amount of atmospheric air flowing into the chamber 7 is minimized.

FIG. 5 is a diagram showing a second adjustment example of the embodiment of FIG. 1, and the same reference numerals as those in FIG. 1 denote the same parts.

The difference between the second adjustment example and the first adjustment example is that the direction of the mouth casing 13 on the outlet 9 side is slightly closer to the conveyor 2.

Therefore, a part of the inert gas ejected from the mouth casing 13 on the outlet 9 side flows to the outlet 9 side of the chamber 7, and the force of suppressing the inflow of the atmosphere from the outlet 9 can be enhanced. it can. Therefore, the ejection amount (ejection speed) of the inert gas ejected from the mouth casing 13 on the solder bath 3 side is increased, and the inert gas laminar flow to the region where the wiring board 1 and the solder melt 4 contact each other. It is desirable to maintain the feed rate at the same level as in the first control example. With this, the atmosphere sealing property on the outlet 9 side and the inlet 8 side of the chamber 7 can be further enhanced.

FIG. 6 is a diagram showing a third adjustment example of the embodiment of FIG. 1, and the same reference numerals as those in FIG. 1 denote the same parts.

The third adjustment example is different from the first adjustment example in that the direction of the rotatable restraining plate 15 is sequentially changed.

Therefore, the inert gas ejected from the mouth casing 13 to form the laminar flow gradually decelerates while reaching the jet waves of the primary jet tank 5 and the secondary jet tank 6, and finally the inlet 8 Side restraint Plate 11 is sealed by the labyrinth channel. Such an adjustment example is effective when a large component is mounted on the wiring board 1.

That is, since the large parts easily draw out the atmosphere in the chamber 7 to the outside, by setting the laminar flow velocity in the area of the secondary jet tank 6 at a high level, the area of the primary jet tank 5 is not sufficiently exposed. It is possible to form an inert gas atmosphere with low oxygen concentration by supplying active gas. The equilibrium point for sealing the atmosphere is also optimized.

FIG. 7 is a diagram showing a fourth adjustment example of the embodiment of FIG. 1, and the same reference numerals as those in FIG. 1 denote the same parts.

The difference between the fourth adjustment example and the first adjustment example is that the rotatable restraining plates 15 are all directed vertically to the transport conveyor 2, and the mouth casing 13 on the solder bath 3 side is arranged. Is a point facing the direction of the transfer conveyor 2, and the mouth casing 13 on the outlet 9 side is directed in the direction opposite to the transfer direction of the wiring substrate 1 (direction of arrow A).

An example of such adjustment is when the transport speed of the wiring board 1 is relatively slower than a general transport speed (eg, 1 m / minute) (eg, 0.6 m / minute), If the temperature of the preheat (not shown) is relatively higher than the general temperature (for example, 80 to 120 ° C) (for example, 150 ° C), the temperature of the solder melt 4 is the general temperature (for example, 150 ° C). For example, it is effective when the temperature is relatively higher than 250 ° C. (for example, 350 ° C.). That is, the suppression plate 15 increases the thermal convection suppression force of the atmosphere. Further, since the heat convection suppressing force of the mouth casing 13 on the solder bath 3 side is also increased, the atmosphere sealing property as a whole can be kept good.

In this case, the ejection amount (ejection speed) of the inert gas ejected from the mouth housing 13 on the solder bath 3 side is relatively small, and the inert gas ejected from the mouth housing 13 on the outlet 9 side is ejected. By making the amount (jetting speed) relatively large, the laminar flow of the inert gas flowing toward each jet tank 5, 6 can be maintained at the same level as in the first adjustment example.

8A to 8D are side cross-sectional views showing an example of the directivity of the mouth casing 13 with respect to the direction of the nozzle 14, showing the direction of ejection of the inert gas ejected from the ejection holes 25 of the nozzle 14. The directivity of the inert gas ejected from the mouth casing 13 at the time of adjusting is described. The directivity of the inert gas is shown by the jet velocity distribution.

FIG. 8A is an example in which the ejection holes 25 of the nozzle 14 face the direction of the opening 24 of the mouth casing 13, and in this case, a radial directivity is shown.

FIG. 8B shows an example in which the ejection holes 25 of the nozzle 14 are directed toward the bottom of the mouth casing 13, and in this case, both sides of the mouth casing 13 have directivity.

FIG. 8C is an example in which the ejection holes 25 of the nozzle 14 are obliquely oriented in the opening direction of the mouth casing 13, and in this case, the ejection holes 25 are directed toward the side surface portion of the mouth casing 13 on the side of the ejection holes 25. Shows sex.

FIG. 8D is an example in which the ejection holes 25 of the nozzle 14 are obliquely oriented in the bottom direction of the mouth casing 13, and in this case, the ejection holes 25 are slightly provided on the side surface portion of the mouth casing 13. It shows directivity and does not show strong directivity on the other side.

In this way, by adjusting the direction of the inert gas jetted from the nozzle 14, the directivity of the inert gas jetted from the mouth casing 13 can be changed. Therefore, the laminar flow formation and the sealing property can be adjusted and selected by adjusting the direction of the inert gas ejection along with the direction adjustment of the mouth casing 13.

For example, in the first adjustment example of FIG. 1 and the third adjustment example of FIG. 6, FIG. 8C is selected as the directivity of the mouth casing 13 on the solder bath 3 side, and the directivity of the outlet 9 side is selected. If FIG. 8A is selected for the directivity of the mouth casing 13, the flow of the inert gas ejected from the mouth casing 13 on the solder bath 3 side is the flow of the inert gas ejected from the mouth casing 13 on the outlet 9 side. It acts so as to accelerate, and can form a good laminar flow.

Further, in the second adjustment example of FIG. 5, FIG. 8C is selected as the directivity of the mouth casing 13 on the solder bath 3 side, and the directivity of the mouth casing 13 on the outlet 9 side is selected as shown in FIG. If (b) is selected, the directivity of FIG. 8 (b) has two peaks, so one peak of the inert gas ejected from the mouth casing 13 on the outlet 9 side is the mouth casing on the solder bath 3 side. The flow of the inert gas ejected from 13 can be accelerated, and the other peak can provide the outlet 9 of the chamber 7 with sealing property.

In the fourth adjustment example of FIG. 7, FIG. 8B is selected as the directivity of the mouth casing 13 on the solder bath 3 side, and FIG. 8C is selected as the directivity of the mouth casing 13 on the outlet 9 side. ) Is selected, in the mouth casing 13 on the solder bath 3 side, two directivity peaks operate so as to form a double gas curtain, and the inert gas ejected from the mouth casing 13 on the outlet 9 side. Can form a laminar flow.

The directivity of the mouth casing 13 in FIG. 8D has a relationship in which the relative ratio of the two peaks in FIG. 8B is variable. Therefore, it is effective in slightly adjusting the directivity of the mouth casing 13 on the outlet 9 side in the second adjustment example and the mouth casing 13 on the solder bath 3 side in the fourth adjustment example.

The above-described first to fourth adjustment examples and the adjustment examples illustrated in FIGS. 8A to 8D are merely examples of the adjustment examples, and the conclusion is concluded. Is inactive in response to changes in the soldering process environment parameters such as the transport speed and preheat temperature of the wiring board 1, the shape and size of the components mounted on the wiring board 1, the temperature of the solder melt 4, and so on. Optimum laminar flow formation and supply of the inert gas from the gas supply chamber 12 to the region where the solder melt 4 of each of the jet tanks 5 and 6 and the wiring substrate 1 come into contact with each other, and the atmosphere sealing property of the chamber 7. You can adjust

FIG. 9 is a side sectional view showing a second embodiment of the present invention.

That is, the difference from the first embodiment of FIG. 1 is that the labyrinth flow path is not provided by the restraint plate 11 of FIG. 1 formed at the inlet 8 of the chamber 7 with the transfer conveyor 2 sandwiched therebetween. Is. Such a configuration is effective when the opening area of the inlet 8 of the chamber 7 is small. That is, when the size (particularly the height) of the components mounted on the wiring board 1 is small, the atmosphere forming device having such a configuration is sufficient. By the way, the current situation in which the wiring board 1 composed of surface-mounted components is generalized corresponds to this.

FIG. 10 is a side sectional view showing a third embodiment of the present invention.

That is, the point different from the first embodiment of FIG. 1 is that the inlet 8 of the chamber 7 is not provided with the labyrinth flow path by the inhibition plate 11 of FIG. The exit 9 of the chamber 7 is provided with a labyrinth flow path formed by an inhibition plate 11 formed by sandwiching the conveyor 2.

Such a configuration is effective when the transport speed of the wiring board 1 is high. That is, it is possible to significantly suppress the outflow of the inert gas from the chamber 7 by the wiring board 1 and the conveyor 2.

In the third embodiment, the labyrinth flow path can be also provided on the inlet 8 side of the chamber 7 by the restraint plate 11 formed by sandwiching the conveyor 2. As a result, it becomes possible to significantly suppress the inflow of the atmosphere into the chamber 7.

FIG. 11 is a side sectional view showing a fourth embodiment of the present invention.

That is, the difference from the first embodiment of FIG. 1 is that the restraint plate 31 provided on the wall of the chamber 7 above the region where the solder melt 4 and the wiring board 1 are in contact does not rotate. That is the point. That is, the restraint plate 31 is fixed directly to the chamber 7, or is fixed so that the rotation shaft 16 of FIG. 1 does not rotate.

Such a configuration is sufficient when there is no extreme change in the conveyance speed of the wiring board 1, the preheat temperature, the size of the components mounted on the wiring board 1, the temperature of the molten solder, and the like.

Of course, the present invention can be constructed by combining the above-described first to fourth embodiments. In other words, it is only necessary to select the optimum configuration according to the soldering process environment.

[0065]

[Effect of device]

 As described above, according to the present invention, an inert gas supply chamber for supplying an inert gas into the chamber is formed on the outlet side of the chamber, and the chamber is provided in the inert gas supply chamber with respect to the transport conveyor. On the upper side and the lower side of the wiring board, there are provided mouth casings having a U-shaped cross section that project toward the conveyor in a direction intersecting the conveyance direction of the wiring board. A nozzle for ejecting the inert gas is provided so that its ejection direction is variable, and further, a plate surface is arranged on the upper inner wall of the area of the solder bath in the chamber in a direction intersecting the transfer direction of the wiring board, Moreover, since a plurality of restraint plates are arranged in parallel in the direction of projecting toward the conveyor, it is possible to form and supply a laminar flow of the inert gas by adjusting the opening direction of the mouth casing and the jetting direction of the nozzle. Navi Since the atmosphere sealability of the chamber can be optimally selected, the inert gas atmosphere in the enclosed bath area can be stably maintained, and therefore the entire chamber can be made smaller, which reduces the cost of the soldering device and the conventional method. Can be applied to soldering equipment. Further, since the solder melt can be prevented from being oxidized, it has an advantage that lead pollution can be suppressed and a normal soldering environment can be realized.

Further, since the restraint plate provided in the area of the solder bath is rotatably provided, there is an advantage that the flow state of the inert gas atmosphere in the chamber can be easily adjusted.

Further, in the chamber, at least one of the inlet and the outlet thereof is provided with a plurality of restraining plates fixed in a direction intersecting with the carrying direction of the wiring board and projecting toward the carrying conveyor. Therefore, there is an advantage that the outflow of the inert gas in the chamber and the inflow of the outside air in the chamber can be prevented, and the sealing property in the chamber can be kept higher.

Further, since the chamber is formed so as to be divided into an upper chamber and a lower chamber with respect to the transfer conveyor, there is an advantage that the installation work and maintenance of the chamber are easy and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a first embodiment of an inert gas atmosphere forming device of a soldering device according to the present invention.

2 is a cross-sectional view taken along the line II of the embodiment of FIG.

3 is an enlarged perspective view showing details of the mouth casing of the embodiment of FIG. 1. FIG.

FIG. 4 is a perspective view showing a rotation mechanism of the inhibition plate of the embodiment of FIG.

5 is a plan view for explaining a second adjustment example of the embodiment of FIG. 1. FIG.

FIG. 6 is a side view for explaining a third adjustment example of the embodiment of FIG.

FIG. 7 is a side view for explaining a fourth adjustment example of the embodiment of FIG.

8 is a side sectional view showing an example of the direction of the nozzle and the directivity of the mouth casing in the embodiment of FIG.

FIG. 9 is a side sectional view showing a second embodiment of the inert gas atmosphere forming device of the soldering device according to the present invention.

FIG. 10 is a side sectional view showing a third embodiment of the inert gas atmosphere forming device of the soldering device according to the present invention.

FIG. 11 is a side sectional view showing a fourth embodiment of the inert gas atmosphere forming device of the soldering device according to the present invention.

[Explanation of symbols]

 1 Wiring Board 2 Conveyor 3 Solder Tank 4 Solder Melt 7 Chamber 7A Upper Chamber 7B Lower Chamber 8 Inlet 9 Outlet 11 Suppression Plate 12 Inert Gas Supply Chamber 13 Mouth Housing 14 Nozzle 15 Suppression Plate 16 Rotating Shaft 24 Opening

Claims (4)

[Scope of utility model registration request] 1. An inert gas atmosphere forming device for a soldering device, comprising: a chamber for holding an area of a solder bath for soldering a wiring board transported by a transport conveyor in an atmosphere of an inert gas, comprising: An inert gas supply chamber for supplying an inert gas into the chamber is formed on the outlet side of the chamber, and the wiring board is provided on the upper side and the lower side of the chamber with respect to the transfer conveyor in the inert gas supply chamber. Nozzle for ejecting the inert gas into the inside of the mouth casing is provided with a mouth casing having a U-shaped cross section that projects toward the conveyer conveyor in a direction intersecting with the conveying direction of the mouth casing. Is provided so that its ejection direction is variable, and further, a plate surface is arranged on the upper inner wall of the region of the solder bath in the chamber in a direction intersecting the transport direction of the wiring board, and Inert gas atmosphere forming device of the soldering apparatus in which a plurality of inhibit plates in a direction protruding toward the bare is characterized in that it is arranged. 2. The inert gas atmosphere forming device of a soldering device according to claim 1, wherein a restraining plate provided in the area of the solder bath is rotatably provided. 3. The chamber has plate surfaces arranged in at least one of an inlet and an outlet thereof in a direction intersecting with a transfer direction of a wiring board, and a plurality of restraining plates arranged in parallel in a direction projecting toward a transfer conveyor. The inert gas atmosphere forming device of the soldering device according to claim 1 or 2, characterized in that. 4. The inert gas for a soldering apparatus according to claim 1, wherein the chamber is formed so as to be divided into an upper chamber and a lower chamber with respect to the conveyor. Atmosphere forming device.