JPH088528A - Vapor reflow soldering equipment - Google Patents

Abstract

(57) [Abstract] [Purpose] Reflow soldering that can remove the flux that melts and mixes into the heat medium from the solder paste on the object to be processed, has a high operating rate, is easy to maintain, and has high reliability. Provide a device. An object to be processed 16 is conveyed to a steam generation tank 4 for generating a saturated steam 13 of a heat medium, and the saturated steam 13 is brought into contact with the object to be processed 16 to heat and melt the solder of the object to be processed 16 for soldering. In the vapor reflow soldering device, the flux remover 36 is replaceably provided in the return passage 17 on the carry-in side and the carry-out side, and the steam generating tank 4 is provided.
Of the liquefied heat medium located above the steam generating part of the
Is provided with a plate 39 for guiding the heat medium saturated steam 13 to the plate 39, and a protruding portion 41 for preventing the liquefied heat medium from falling into the steam generation tank 4 is provided in the plate 39. Provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vapor reflow soldering apparatus, and in particular, prints so-called flat pack ICs in which electrode terminals are taken out in a plane in four directions, and imposition chip parts such as resistors and capacitors. The present invention relates to a vapor reflow soldering device suitable for high-density mounting by soldering on a wiring board such as a board (hereinafter collectively referred to as a circuit board).

[0002]

2. Description of the Related Art In recent years, high-density mounting of electronic parts on a circuit board is progressing more and more, but the soldering work for adhering electronic parts such as ICs and chip parts to the circuit board is the final step of the line. Moreover, the soldering technology has come to be regarded as the most important technology in the line. Recently, it is necessary to improve the uniformity of temperature distribution in the furnace for soldering work and to avoid harmful heating of electronic parts.
There is a vapor reflow soldering apparatus that uses a vapor having a large specific gravity against air as a heat medium and uses the condensation latent heat to heat an object to be processed such as a circuit board having electronic components mounted on a board on which a solder paste is printed.

This device is disclosed, for example, in Japanese Patent Laid-Open No. 63-903.
As described in Japanese Patent Publication No. 61-61, it is a soldering apparatus provided with a steam generation tank for soldering a circuit board by passing it through saturated steam of a heat medium having a large specific gravity to air as described above. A conventional vapor reflow soldering apparatus will be described with reference to FIGS. 10 and 11. Figure 10
FIG. 11 is a vertical sectional view of a conventional vapor reflow soldering device, and FIG. 11 is a sectional view taken along the line DD of FIG. An object 16 to be processed such as a circuit board moves in the apparatus shown in FIG. 10 from the left side to the right side of FIG. 10 by the conveyor 15 (hereinafter, the apparatus inlet direction of the conveyor 15 is the carry-in side, and the outlet direction is the carry-out side. Called).

The apparatus shown in FIGS. 10 and 11 includes a steam generation tank 4, a carry-in side transport path 5, a carry-out side transport path 6, a heater 7.
Carry-in side cooler 8, carry-out side cooler 9, carry-in side exhaust port 10,
The reflow unit 1 including the discharge side exhaust port 11, the preheating unit 2 including the preheating heater 14, the cooling unit 3 including the cooling fan 18, and the object 16 to be conveyed from left to right in FIG. A drive system including a conveyor 15, a drive sprocket 19, a drive motor 20, an idler 21, and the like, and a pipe 2.
2, a heat medium recovery system including a recovery device 23 having a cooler 24 and a demister 25, a hydroxide remover 26, a circulation pump 27, and the like, a temperature sensor 28, a temperature controller 29, and a power controller 30.
And the like, and a filtering system (not shown) for removing the flux mixed in the heat medium 12 in the steam generation tank 4 and the like.

The steam generating tank 4 has a bottom portion 3 which serves as a steam generating portion.
The heat medium 12 is stored in 5 and is separated from the chamber in which the carry-in side cooler 8 and the carry-out side cooler 9 are located by the partition wall 34 opened at the bottom,
The bottom portion 35 and the partition wall 34 are connected to each other via a return passage 17.

The operation of the conventional vapor reflow soldering apparatus thus configured will be described. When power is supplied to the preheating heater 14 and the heating heater 7 by starting the apparatus, the heat medium 12 stored in the bottom portion 35 of the steam generation tank 4 is
Since the latent heat of vaporization is about 1/25 of water, the heater 7
Is heated and vaporized immediately to generate saturated vapor 13. Saturated steam 13 rises in the steam generation tank 4, part of which flows from the lower steam discharge port 33, and the remaining part of the steam that flows through the side wall passage 31 and the upper steam discharge port 32, and is the steam necessary for reflowing the workpiece 16. Secure the surface.

Since the specific gravity of the saturated vapor 13 of the heat medium 12 is as high as about 20 times that of air, in order to raise the vapor surface so that the saturated vapor of the heat medium 12 is sufficiently in contact with the object to be treated 16,
A large amount of steam is generated from the steam generation tank 4. The height of the saturated steam 13 in the steam generation tank 4 is heated via a power controller 30 so that the saturated steam 13 reaches a predetermined temperature by a temperature sensor 28 and a temperature controller 29 movably provided in the steam generation tank 4. It is controlled by controlling the electric power to the heater 7 and kept at a predetermined value.

The article to be processed 16 is carried in the apparatus by the conveyor 15. The object to be treated 16 is first heated by the preheater 14 in the preheating unit 2, is then carried into the reflow unit 1, and the solder is heated and melted by the latent heat of condensation of the saturated steam 13,
The solder is solidified as it enters the unloading-side transport path 6 and solidifies, enters the cooling unit 3, is further cooled by the cooling fan 18, and is unloaded from the apparatus.

The saturated vapor 13 is condensed and liquefied on the object to be treated 16, and the liquefied heat medium drops from the object to be treated 16 toward the lower vapor discharge port 33, the carrying-in side conveying path 5, and the carrying-out side conveying path 6. . The heat medium that has dropped toward the lower steam outlet 33 returns directly to the steam generation tank 4, and the heat medium that has dropped toward the carry-in side transport path 5 and the carry-out side transport path 6 cools the carry-in side cooler 8 and the carry-out side cooler. The steam generation tank 4 is passed through the return passage 17 together with the remaining saturated steam 13 that is cooled and liquefied by the vessel 9.
Return to the bottom of. A slight amount of the steam of the heat medium remaining remains from the carry-in side exhaust port 10 and the carry-out side exhaust port 11, and adheres to the object to be treated 16 and then vaporized and separated from the carry-out side exhaust port 11 through the piping. Recovery device 23 through 22
Flows into the chiller 24, is liquefied by the cooler 24, and is collected and collected by the demister 25. The recovered heat medium is a hydroxide remover 2
Hydrochloric acid is removed by 6 and the steam generation tank 4 is circulated by the circulation pump 27.
Is returned to.

Next, when the soldering work is completed, the heating of the heat medium is stopped, the liquid is collected in an externally provided filtering system, the temperature of the heat medium is lowered, and the flux deposited in the liquid is filtered. Had been removed.

[0011]

The vapor reflow soldering apparatus as described above has the following problems. (1) In the reflow chamber, the saturated vapor of the heat medium that has heated the object to be processed is liquefied, and part of it accumulates on the upper surface of the object to be processed, so the flux in the solder paste melts into the heat medium liquid and falls. , Collects at the bottom of the steam generation tank through the return passage on the carry-in side and the carry-out side and the lower steam discharge port. Also, the evaporated part of the flux becomes steam during heating and most of it is exhausted to the outside of the equipment, but part of the solid part of the flux also becomes steam during heating, and the steam of the heat medium is absorbed by the coolers on the loading and unloading sides. It liquefies and returns from the return passage to the bottom of the steam generation tank where it accumulates.

The flux accumulated in the lower portion of the steam generation tank as described above is heated by the heater at the bottom of the steam generation tank,
It becomes steam together with the heat medium, is liquefied by being cooled in the carry-in side cooler and the carry-out side cooler, and returns to the steam generating tank through the return passage. By repeating the above-described operation, the flux is accumulated in the heat medium in the steam generation tank. In the conventional apparatus, the removal of the flux is performed after the heating of the apparatus is stopped. Therefore, the concentration of the flux in the heat medium liquid increases during the operation of the apparatus and adheres to the surfaces of the coolers and heaters on the carry-in side and the carry-out side, and after a long time, carbonization and removal becomes difficult. Since the adhesion of the flux hinders heat exchange, it causes a disconnection due to overheating of the heater and a decrease in the cooling capacity of the cooler, which lowers the reliability of the device. In order to remove the above-mentioned flux, it is necessary to periodically stop the apparatus for a long time, which causes a problem such as a decrease in operating rate.

(2) In order to suppress an increase in the flux concentration in the heat medium liquid in the steam generating tank during operation, remove the reflow part from just above the steam generating part at the bottom of the steam generating tank and reflow the object to be treated. It suffices that the heat medium liquid that falls due to the falling heat is dropped to the outside of the steam generating portion of the steam generating tank, the dropped heat medium is accommodated to remove the flux, and then returned to the steam generating portion in the steam generating tank. As such an apparatus, for example, Japanese Patent Laid-Open No. 58-
There is one described in Japanese Patent No. 51592. However, in the above apparatus, the size of the steam generation tank becomes large, so that the height of the saturated steam tends to be unstable, and the reliability of the soldering work decreases. Further, in order to secure the height of the saturated steam necessary for reflowing the object to be processed, it is necessary to generate a larger amount of steam, which requires a large amount of heat.

The present invention has been made in order to solve the above-mentioned problems of the prior art, and an object of the present invention is to remove the flux which is melted and mixed into the heating medium from the solder paste on the object to be treated. It is possible to provide a reflow soldering device that can be manufactured, has a high operating rate, is easy to maintain, and has high reliability.

[0015]

In order to achieve the above object, the vapor reflow soldering apparatus according to the present invention has a structure in which an object to be processed, which is an electronic component mounted on a circuit board coated with solder, is preheated. And conveyed so as to pass through the reflow section, preheat the object to be processed in the preheating section to a desired temperature, melt the solder by the heat medium saturated steam generated in the steam generation tank of the heat medium in the reflow section, and to the reflow section In the subsequent cooling section, cold air was blown to solidify the solder and solder the electronic components onto the circuit board, and the vapor of the heat medium flowing out of the steam generation tank was provided in the inlet and outlet passages following the steam generation tank. In a vapor reflow soldering device that liquefies by a cooler and recovers the liquefied heat medium to the steam generation tank through a return passage that connects the inlet and outlet passages and the bottom of the steam generation tank And a flux removing means for removing flux is provided in the return passage on the unloading side so as to be replaceable, and is located above the steam generation portion of the steam generation tank and inclined toward at least one of the return passages to be liquefied. A shield plate for guiding the heat medium to the return passage is provided, and an opening portion for allowing the heat medium saturated vapor generated in the steam generation tank to pass is provided in the shield plate, and the vapor generation tank for the liquefied heat medium is provided in the opening portion. Is provided with a protruding portion for preventing the falling.

More specifically, the projecting portion provided in the opening of the shielding plate is formed so as to cover the opening at least above the inclined surface of the shielding plate. Further, an opening for overflow of the heat carrier liquid is provided in the wall constituting the steam generation tank above the return passage provided with the flux removing means, and an eave-shaped projection facing the return passage is provided in this opening. It is provided.

[0017]

The function of the above technical means is as follows. The saturated steam of the heat medium generated from the steam generation tank passes through the opening of the shielding plate to form a steam surface and heat the object to be processed on the conveyor. The saturated vapor of the heat medium that has heated the object to be processed is liquefied and a part thereof is accumulated on the upper surface of the object to be processed, so that the flux in the solder paste is melted into the heat medium. The heat medium drops from the object to be treated, but the heat medium that has dropped above the steam generation tank drops onto the shielding plate, and the remaining heat medium drops to the carry-out side transport path and the carry-in side transport path.

The heat medium that has fallen and adhered to the shield plate moves along the inclined surface of the shield plate and falls into the return passage, and together with the heat medium that has dropped into the remaining carry-out side transport path and carry-in side transport path, the return path Leading to. The heat medium that has melted the flux returns to the lower part of the steam generation tank through the return passages on the carry-in side and the carry-out side. Therefore, the flux can be efficiently removed by providing flux removing means in the return passages on the carry-in side and the carry-out side. . Since the steam generation tank has the same structure as the conventional one except that a shield plate is added, its size is also the same as the conventional one.
The saturated steam surface can be secured with the same amount of heat as the conventional one, and the saturated steam surface is also stable.

By the above, the reflow solder which is capable of efficiently removing the flux which is melted and mixed in the heat medium on the object to be processed during the operation of the apparatus, has a high operation rate, is easy to maintain, and is highly reliable. An attachment device can be provided.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Each embodiment of the present invention will be described below with reference to FIGS. [Embodiment 1] FIG. 1 is a longitudinal sectional view showing the configuration of a reflow soldering apparatus according to an embodiment of the present invention, and FIG.
3 is a sectional view taken along the line AA of FIG. 3, FIG. 3 is a sectional view taken along the line BB of FIG. 1, and FIG. 4 is a partial detailed perspective view showing the shielding plate portion of FIG. In FIGS. 1 to 4, the same reference numerals as those shown in FIGS. 10 and 11 are the same as those in the conventional art, and thus the description thereof will be omitted.

The present embodiment shown in FIGS. 1 to 4 is different from the prior art shown in FIGS. 10 and 11 in that the liquid level of the heat medium 12 in the return passages 17 on the carry-out side and the carry-in side is different from that of the prior art. The replaceable flux remover 36 is provided on the upper portion. The flux remover 36 is configured to allow the heat medium to pass therethrough, and has the inside thereof filled with an adsorbent on the surface in contact with the heat medium. The adsorbent contains, for example, aluminite powder as a main component.

Further, in this embodiment, the carry-in side cooler 8 and the carry-out side cooler 9 are provided above the flux remover 36.
Overflow holes 37 related to the overflow openings are provided in the partition walls 34 on the carry-in side and carry-out side below. Then, on the overflow hole 37, a projection 3 having an eaves-like shape toward the return passage 17 side so that the heat medium liquefied by the reflow action does not directly enter the overflow hole 37.
7A is formed.

Further, in this embodiment, an opening 38 and an opening / closing door 42 for exchanging the flux remover 36 are provided in the upper part and the lower part of the carry-in side transport path 5, and the carry-out side transport path 6 is provided.
Is provided with an opening 38 for replacing the flux remover 36, and the flux remover 36 is replaced with the carry-in side cooler 8 and the carry-out side cooler 9 below the carry-out side and carry-in side openings 38, respectively. At this time, gaps 8a and 9a are provided in the rows of the coolers so that the replacement work can be performed.

Further, in this embodiment, the lower steam discharge port 3
3 below, above the steam generation section of the steam generation tank 4,
A plate 39 relating to the shielding plate is provided. The plate 39 has an opening through which the saturated steam 13 of the heat medium generated in the steam generation tank 4 passes, and a protrusion for preventing the liquefied heat medium from falling into the steam generation tank 4 is provided in this opening. Be prepared. The plate 39 is arranged so as to be slightly inclined in the direction of at least one of the return passages 17 (the return passage on the unloading side in FIG. 1), and guides the heat medium liquefied by the reflow action to the return passages 17. That is, the heat medium liquid containing the flux that drops from the object to be processed 16 is prevented from falling into the steam generation tank 4, and is guided to the return passage 17 on the carry-out side.

The details of the opening in the plate 39 are shown in FIG. The plate 39 is a so-called shredder shape such as a so-called radish shown in FIG. 4, and the plate 39 is inclined toward the unloading side, and the upper side of the inclined surface is larger than the steam port 40 associated with each opening. The projection 41 is provided so as to cover the entire area from the top to just above the steam port 40. In FIG. 4, a dashed arrow indicates a saturated vapor that passes through the vapor port 40 and rises, and a solid arrow indicates a state in which the liquefied heat medium flows down.

An overflow hole 37 is provided in the return passage 17.
A liquid level detector (not shown) is provided to detect when the liquid level of the heat medium reaches. When the liquid level detector detects the heat medium liquid level, an alarm device (not shown) operates to notify the clogging of the flux remover 36. Steam generation tank 4
When the liquid level of the heat transfer medium reaches the overflow hole 37 of the return passage 17 due to the clogging of the flux remover 36, the bottom 35 of the heater 35 has a sufficient amount of heat transfer medium to prevent overheating of the heater 7. The heat medium 12 is stored.

The operation of the vapor reflow soldering apparatus of this embodiment having the above structure will be described. When the apparatus is activated, electric power is supplied to the preheating heater 14 and the heating heater 7. The heat medium 12 accumulated in the bottom portion 35 of the steam generation tank 4
Since the latent heat of vaporization is about 1/25 of water, it is heated by the heater 7 and immediately vaporizes to generate saturated vapor 13. The saturated steam 13 rises in the steam generation tank 4, and a part of the saturated steam 13 passes through the steam port 40 of the plate 39 from the lower steam discharge port 33, and the rest flows from the upper steam discharge port 32. The saturated vapor surface necessary for reflowing the solder of the processing object 16 is secured.

The saturated steam 13 is condensed and liquefied on the object 16 to be processed, and the latent heat of the condensed steam 13 heats the object 16 to be processed. At that time, the flux of the solder paste applied to the object to be processed 16 melts into the condensed and liquefied heat medium. Part of the heat medium that has liquefied and melted the flux is
3 falls directly on the plate 39 provided directly below. The heat medium that has dropped onto the plate 39 is vaporized by the protrusion 41 to the steam port 40.
Is prevented from falling into the steam generation tank 4 from the plate 3
The inclination of 9 leads to the return passage 17 on the unloading side.

The remaining condensed and liquefied heat medium that has not fallen to the plate 39 other than the above drops in the carry-in side transport passage 5 or the carry-out side transport passage 6 and flows into the return passage 17. Most of the remaining saturated steam 13 that has not condensed and liquefied on the object to be processed 16 and steam including flux generated by heating the object to be processed 16 in the reflow part 1 are the inlet side cooler 8 and the outlet side cooler. It is cooled in 9 and liquefied and flows into the return passage 17. A slight amount of heat medium or flux vapor left unliquefied in the carry-in side cooler 8 or the carry-out side cooler 9 and a part of the object to be treated 16
The heat medium or flux vapor that remains above and is evaporated thereafter is recovered from the carry-in side exhaust port 10 or the carry-out side exhaust port 11. The vapor is liquefied and recovered from the carry-in side exhaust port 10 and the carry-out side exhaust port 11 through the exhaust pipe 22 into the recovery device 23. The heat medium recovered by the recovery device 23 is subjected to hydroxy removal by the hydroxy remover 26, and the circulation pump 27
Return path 1 above the flux remover 36 on the unloading side
Returned to 7

Since the steam of the heat medium flowing out of the steam generating tank 4 and the heat medium condensed and liquefied return to the bottom portion 35 of the steam generating tank 4 through the return passage 17, the flux remover 36 is provided in the return passage 17. By providing it, the flux can be removed efficiently. The flux melted in the heat medium passes through a flux remover 36 provided in the return passage 17 so that the flux is adsorbed and removed and returns to the bottom portion 35 of the steam generation tank 4.

When the flux remover 36 is clogged due to a foreign substance falling during the operation of the apparatus and the heat medium is less likely to return to the steam generation tank 4, and a liquid pool of the heat medium occurs in the return passage 17, Partition wall 34 above the flux remover 36
Since it returns to the bottom portion 35 of the steam generation tank 4 through the overflow hole 37 provided in the above, the heater 7 can be prevented from overheating and the amount of the heat medium can be secured, so it is not necessary to immediately stop the apparatus. When the liquid level of the heat medium 12 rises to the overflow hole 37, the liquid level detector described above detects the liquid level and activates the alarm device to notify the clogging of the flux remover 36.

When the flux adsorption performance is deteriorated and the flux remover 36 is to be maintained, the operation of the apparatus is stopped, and the opening 38 and the carry-in side transport path provided at the upper portions of the carry-in side transport path 5 and the carry-out side transport path 6 are stopped. The opening / closing door 42 provided at the lower part of 5 is opened to replace the flux remover 36.

In this way, the bottom portion 35 of the steam generation tank 4 is
To remove the flux attached to the heater 7, the partition wall 34, and the bottom portion 35 facing the inside of the steam generation tank 4, and to remove the flux attached to the heater 7, the partition wall 34, and the bottom portion 35. Maintenance period is extended,
The operating rate is improved and the reliability of the device is improved. The structure of the steam generation tank 4 is the same as the conventional one except that the plate 39 is added, and therefore the volume thereof is also the same as the conventional one, so that the saturated steam surface can be secured with the same amount of heat as the conventional one, and the volume is also the same. Since it is equivalent, its saturated vapor surface is also stable.

[Embodiment 2] FIG. 5 is a vertical sectional view showing the structure of a reflow soldering apparatus according to another embodiment of the present invention, and FIG. 6 is a sectional view taken along the line CC of FIG. In the figure, those having the same reference numerals as those in FIGS. 1 to 3 are the same parts as those in the previous embodiment, and therefore their explanations are omitted. This embodiment is shown in FIGS.
6 is different from the embodiment shown in FIG. 2 in that the flux remover 36 is arranged on the side wall 43 side of the steam generation tank 4 so as to be offset, and the side wall 43 is provided with an airtight inspection port 44 capable of exchanging the flux remover 36. It is provided.

According to the embodiment shown in FIGS. 5 and 6, in the flux remover 36, the side wall 43 is opened by opening the inspection port 44.
Since it can be replaced from the side, maintenance becomes easier. Further, it is not necessary to provide gaps 8a, 9a through which the flux remover 36 can be exchanged in the row of the carry-in side cooler 8 and the carry-out side cooler 9, so the carry-in side cooler 8 and the carry-out side cooler 9
Can be arranged continuously, the cooling efficiency can be increased, and the heat medium can be efficiently recovered, which is an effect peculiar to this embodiment.

[Embodiment 3] FIG. 7 is a vertical sectional view showing the structure of a reflow soldering apparatus according to still another embodiment of the present invention. In the figure, those having the same reference numerals as those in FIG. 1 are the same parts as those in the previous embodiment, and therefore their explanations are omitted. Figure 7
1 is different from the embodiment of FIG. 1 in that the return passage of the heat medium 12 in the steam generation tank 4 is constituted by the external pipe 45, and the flux remover 36 is provided in the passage. is there. In the present embodiment, an airtight inspection port 46 that is openable and closable is provided so that the flux remover 36 can be easily replaced, and the bottom 35 of the steam generation tank 4 is provided below the tip heat medium liquid 12 surface of the pipe 45. Connected.

According to this embodiment, by opening the inspection port 46, the flux remover 36 can be provided without touching the saturated steam 13.
Since it can be replaced, replacement becomes easier and safety is improved. In the embodiment shown in FIG. 1, the plate 39 is provided so as to be tilted toward the carry-out side, but the apparatus shown in FIG. 7 is shown as being tilted toward the carry-in side. The direction in which the plate 39 is tilted is a design problem that is determined in consideration of the throughput of the flux remover 36, maintainability, and the like. The plate 39 may be tilted toward the carry-in side, and the central portion is high and the carry-in and carry-out sides are high. It does not matter if the heat medium flows through both of them.

In each of the above embodiments, the plate 39 has a so-called shredder shape such as a radish, but it can be guided below the inclined surface without dropping the liquid that drops on the plate 39. For example, the plate may be divided into a plurality of parts and arranged so as to be inclined, the upper part of the inclined surface may be arranged below the upper plate, and the inclined plate may be moved on the upper plate to receive the heat medium to be dropped. It may be an eliminator-like one in which the lower plate is arranged.

[Embodiment 4] FIG. 8 is a perspective view of a plate for passing vapor of a vapor reflow soldering apparatus according to still another embodiment of the present invention. In the plate 39A relating to the shield plate shown in FIG. 8, the projecting portion 41A is formed by edging the circular steam port 40A so as to prevent only the heat medium moving on the plate 39A from falling. In this case, the amount of the heat medium liquid that drops from the steam port 40A to the steam generation tank 4 is equal to the value obtained by multiplying the area ratio of the steam port 40A on the plate 39A by the total amount of the heat medium that drops on the plate 39. Since the area of the steam port 40A is smaller than that of the plate 39A, the amount of the heat medium liquid that drops from the steam port 40A into the steam generation tank 4 is also small, and the flux concentration in the heat medium 12 in the steam generation tank 4 is small. Can be suppressed.

[Embodiment 5] FIG. 9 is a perspective view of a plate for passing vapor of a vapor reflow soldering apparatus according to still another embodiment of the present invention. In the plate 39B relating to the shielding plate shown in FIG.
It is formed into a so-called jar shape, which is inclined and inward toward 0B. By doing so, the flow velocity of the steam blown out from the steam port 40B becomes faster, and the direction of the heat medium falling from above the steam port 40B can be shifted from the steam port 40B. Has the effect of reducing falling. Further, if the shapes as shown in FIGS. 8 and 9 are used, the plates 39A and 39B can be manufactured by press molding, so that the manufacturing is easy and the cost thereof is low.

[0041]

As described in detail above, according to the present invention, it is possible to remove the flux which is melted and mixed in the heat medium from the solder paste on the object to be processed, the operating rate is high, and the maintenance is easy. An easy and highly reliable reflow soldering device can be provided.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing the configuration of a reflow soldering apparatus according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

3 is a cross-sectional view taken along the line BB of FIG.

FIG. 4 is a partial detailed perspective view showing a shielding plate portion of FIG.

FIG. 5 is a vertical cross-sectional view showing the configuration of a reflow soldering device according to another embodiment of the present invention.

6 is a cross-sectional view taken along the line CC of FIG.

FIG. 7 is a vertical cross-sectional view showing the configuration of a reflow soldering device according to still another embodiment of the present invention.

FIG. 8 is a perspective view of a vapor-passing plate of a vapor reflow soldering apparatus according to another exemplary embodiment of the present invention.

FIG. 9 is a perspective view of a plate for passing vapor of a vapor reflow soldering device according to still another exemplary embodiment of the present invention.

FIG. 10 is a vertical sectional view showing a conventional vapor reflow soldering device.

11 is a sectional view taken along the line DD of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Reflow part, 2 ... Preheating part, 3 ... Cooling part, 4 ... Steam generation tank, 5 ... Carrying-in side conveying path, 6 ... Carrying out side conveying path, 7 ... Heating heater, 8 ... Carrying-in side cooler, 8a ... Gap , 9 ... Carry-out side cooler, 9a ... Gap, 10 ... Carry-in side exhaust port, 11 ... Carry-out side exhaust port, 12 ... Heat medium, 13 ... Saturated steam, 14 ... Preheat heater, 15 ... Conveyor, 16 ... Processed object , 17 ... Return passage, 18 ... Cooling fan, 22 ... Exhaust pipe, 23 ... Recovery device, 28 ... Temperature sensor, 29 ... Temperature controller, 30 ... Power controller, 32 ... Upper steam outlet, 33 ... Lower steam outlet Outlet, 34 ... Partition wall, 35 ... Bottom plate, 36 ... Flux remover, 37 ... Overflow hole, 37A ... Projection, 38 ... Opening part, 39, 39A, 39B ... Plate, 40, 40
A, 40B ... Steam port, 41, 41A, 41B ... Projection part,
42 ... Open / close door, 43 ... Side wall, 44 ... Inspection port, 45 ... Piping, 46 ... Inspection port.

Claims (3)

[Claims] 1. An object to be processed in which electronic parts are mounted on a circuit board coated with solder is conveyed so as to pass through a preheating section and a reflow section, and the object to be processed is preheated to a desired temperature in the preheating section, In the reflow part, the heat medium saturated steam generated in the steam generation tank of the heat medium melts the solder, and in the cooling part following the reflow part, cold air is blown to solidify the solder and solder the electronic components onto the circuit board The heat medium vapor flowing out from the generation tank is liquefied by the coolers provided in the inlet and outlet passages following the steam generation tank, and the liquefied heat medium is connected to the inlet and outlet passages and the bottom of the steam generation tank. In a vapor reflow soldering device that collects in a steam generation tank through a return passage connected to a flow passage, flux return means for removing flux is replaceably provided in the return passage on the carry-in side and the carry-out side. A shielding plate that is located above the steam generating portion of the steam generating tank and is inclined toward at least one of the return passages and that guides the liquefied heat medium to the return passage. 2. A vapor reflow soldering device, characterized in that an opening is provided through which the saturated heat medium vapor is passed, and a protrusion is provided in this opening to prevent the liquefied heat medium from falling into the vapor generation tank. 2. The vapor according to claim 1, wherein the projection provided in the opening of the shield plate is formed so as to cover the opening from at least above the inclined surface of the shield plate. Reflow soldering equipment. 3. An overflow opening for a heat carrier liquid is provided in a wall constituting the steam generating tank at an upper portion of the return passage provided with the flux removing means, and the opening has a visor shape facing the return passage side. The vapor reflow soldering device according to claim 1, further comprising a protrusion.