JP2823996B2 - Method and apparatus for removing fume from soldering equipment in low oxygen atmosphere - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for removing fumes in a low-oxygen atmosphere soldering apparatus for collecting fumes generated during soldering of a printed circuit board.

[0002]

2. Description of the Related Art Conventionally, a soldering apparatus has been provided with a means for transporting a printed circuit board, a preheating section and a soldering section, and these are covered by a chamber to maintain a low oxygen atmosphere. When the printed circuit board is soldered by this soldering device, flux fumes generated by heating the flux and solder fumes generated by the contact of the solder melt with the flux of the printed circuit board are generated. Was treated as follows.

That is, a duct is provided at an appropriate position in a chamber of a soldering apparatus, and fumes are exhausted from the duct by an exhaust fan or the like, or exhausted to the atmosphere from an inlet and an outlet of the chamber.

[0004]

However, there is a problem that when the fumes treated as in the prior art described above are discharged into the atmosphere, they cause air pollution. Also, if fumes contained in the atmosphere in the chamber adhere to the transporting means or the wall surface in the chamber, malfunction occurs in the mechanism or the like, or malfunctions occur due to the adhesion to the sensor or the like, and soldering occurs. There are problems such as deterioration of performance at the time.

Further, when fume adheres to the sealing portion of the chamber, the fume drips and adheres to a printed circuit board, or when fume adheres to an inspection window provided in the chamber for indoor inspection, etc. Monitoring cannot be performed, and it takes time to clean the inside of the chamber.

Further, in a low-oxygen atmosphere soldering apparatus in which an inert gas is sealed, when a large amount of inert gas filled in the soldering apparatus is exhausted by an exhaust fan or the like, the soldering apparatus has a problem. The active gas is diluted, the low oxygen atmosphere becomes unstable and the soldering accuracy becomes poor, so a large amount of inert gas must be replenished and the consumption of inert gas increases. There was a problem. In addition, the atmosphere gas in the chamber is
After removal through a removal device, etc., the above
Forced circulation system that sends atmospheric gas into the chamber
Turbulence in the inert gas atmosphere in the chamber
There is a problem that hunting occurs.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and the fumes generated by soldering of a printed circuit board are collected and adhered by cooling, so that the fumes can be discharged to the atmosphere without being discharged. An object of the present invention is to obtain a method and an apparatus for removing fume in a low-oxygen-atmosphere soldering apparatus in which a low-oxygen atmosphere is stabilized by an active gas.

[0008]

Fume removal method in a low oxygen atmosphere soldering apparatus of the present invention According to an aspect of the may be provided each collection plate each opening formed to the required plurality of positions of the chamber, of these Each collecting plate is cooled by a cooling device, and fumes generated in the chamber are cooled and adhered by the collecting plate to remove fumes in the chamber.

Moreover, fume removal device in a low oxygen atmosphere soldering apparatus, it to the required plurality of locations of the chamber
Respectively opening is formed, each opening of these Chang
And the collection plate to collect the fumes generated in the bus, of these
Is made of respectively removably were freely mounted cooling device for each collection plate.

[0010]

[Action] In fume removal method and apparatus of the present invention, each collection plate provided at a plurality of positions of chambers respectively cooled by cold <br/> retirement system, each collecting plate which is in these cooling In this method, high-temperature fumes generated during soldering of a printed circuit board become condensed and adhere, so that the low-oxygen atmosphere in the chamber due to the inert gas is stabilized without discharging the fumes to the atmosphere. Also, multiple items in the chamber
Each collection where fumes generated in the chamber were cooled
Removed by attaching to plate and flowing out of chamber
The amount of inert gas generated is minimized.

[0011]

1 is a side sectional view showing an embodiment of the present invention, and FIG. 2 is an enlarged sectional view of a fume removing device. In these figures, reference numeral 1 denotes a low-oxygen atmosphere soldering device (hereinafter, referred to as a soldering device).
(Referred to as a soldering device). Reference numeral 2 denotes a chamber filled with an inert gas to maintain a low oxygen atmosphere. And the printed circuit board 3 is held in the chamber 2,
An inlet section 5 and an outlet section 6 through which a conveyor 4 as a conveying means for conveying in the direction of arrow A penetrates are provided. Also,
Inside the chamber 2, a preheater 7 constituting a preheating section and a solder tank 8 constituting a soldering section are provided. 2 and kept in a low oxygen atmosphere.

Reference numeral 9 denotes a large number of openings formed in required portions of the chamber 2. Each of the openings 9 is provided with a fume removing device 21 described later.
The opening 9 is also formed as appropriate in the upper and lower portions near the inlet 5 and outlet 6 sides of the chamber 2, and also above the preheater 7 and the solder bath 8.

Reference numeral 11 denotes inert gas supply nozzles (hereinafter referred to as supply nozzles) which are sequentially arranged in the longitudinal direction of the chamber 2. Each supply nozzle 11 is connected to an inert gas supply source 12 and Supply inert gas.

The fume removing device 21 attached to the opening 9 of the chamber 2 includes a collecting plate 22 and a cooling device 2.
6, packing 27. Also, Hugh
As described above, the system removing device 21
Inactive outside chamber 2 by being installed at 5 and outlet 6
To prevent outflow of conductive gas and to prevent solder bath 8 or
Installed in the area near the reheater 7 where the fume generation rate is high
Flux fume can be collected efficiently by placing
You. Further, the collecting plate 22 is made of stainless steel or the like having a good thermal conductivity, and is formed to be relatively thin in order to enhance cooling efficiency. The collecting plate 22 adheres and collects the fume cooled by the cooling device 26 and the cooling plate 23. The cooling plate 23 is detachably adhered to the collecting plate 22 to cool the collecting plate 22, and is mounted integrally with the cooler 24. 25
Is a fan of the cooler 24. And the cooling plate 23
The cooling device 26 is composed of the cooling device 24 and the cooling device 24. The cooling plate 23 has the trapping plate 22 attached to the chamber 2 by a mounting screw 28 via a packing 27. Further, below the collecting plate 22, a tray (indicated by a two-dot chain line in FIG. 2) 31
Is provided, it is possible to cope with the case where the fume attached to the collecting plate 22 accumulates and drops.

The cooling temperature of each collecting plate 22 is set at a temperature lower than the ambient temperature in the chamber 2. In addition,
The cooling device 26 can be provided on the side surface of the chamber 2 without being limited to the upper and lower surfaces of the chamber 2.

It is needless to say that the cooling device 26 can be cooled by another method. For example, a low-temperature property of nitrogen or the like used for maintaining the chamber 2 in a low oxygen state can be used. That is, nitrogen is filled in a cylinder at a considerably low temperature as liquid nitrogen. In order to fill the chamber 2 with the nitrogen in the low temperature state, it is necessary to raise the temperature to near normal temperature. Therefore, when the temperature of nitrogen is raised to room temperature, a part of a pipe for feeding nitrogen into the chamber 2 can be cooled through the cooling device 26 in order to control the cooling device 26 to a required temperature state. .

Next, the operation will be described. The printed circuit board 3 is held by the conveyor 4 and transported in the direction of arrow A.
Heat treatment is performed by a preheater 7 in a low oxygen atmosphere by an inert gas in the chamber 2, and then, soldering treatment is performed in a solder bath 8.

Next, fumes generated at the time of soldering the printed circuit board 3 are particularly likely to occur when the printed circuit board 3 is subjected to a flux treatment, and the fumes are generated at a high temperature portion in the chamber 2, that is, above the preheater 7 and the solder bath 8. Occur. Thus fumes generated is attached to Atsumariban 22 chilled capturing by the cooling device 26, fumes capturing Atsumariban 22 is reservoir dropwise to the stored pan 31.

Further, the cooling plate 23 contaminated by the attached fume is removed from the chamber 2 and cleaned, and then attached to the chamber 2 again. In addition, when it is stored in the receiving tray 31, it is removed, cleaned, and then attached.

Another embodiment of the present invention will be described with reference to FIGS. 1 and 2 are denoted by the same reference numerals and described.

Reference numerals 9A and 9B denote upper and lower openings formed in upper and lower portions near the inlet 5 and outlet 6 sides of the chamber 2, respectively. However, a lower fume removing device 21B is attached to the lower opening 9B. These fume removing devices 21A and 21B are the same as the fume removing device 2 described above.
1 is configured in the same manner.

In the upper fume removing device 21A, 2
Reference numeral 9 denotes a fin integrally fixed to at least the collecting plate 22.
It is intended to make fume adhesion efficient. And
The fin 29 is attached so that its lower end is inclined inward of the chamber 2. Further, at the lower end of the fin 29, a storage portion 30 for storing the fume adhered by cooling after the fume is collected is formed. When the storage section 30 is not formed, the receiving tray 31 is provided below the fin 29. The direction of inclination of the fins 29 on the inlet 5 side is opposite to the direction of the fins 29 mounted on the outlet 6 side, and the center of each of the fins 29 on both sides in the longitudinal direction of the chamber 2 (the direction of arrow A). It is almost symmetrical as an axis.

Next, the operation will be described. Hot fumes generated during soldering of the printed circuit board 3, deposited in the chamber 2 flows in both directions of the inlet portion 5 and the outlet 6, it is cooled to Atsumariban 22 catching fin 29 of the upper fume removal device 21A I do. When the attached fumes are accumulated, they flow down along the fins 29, and are stored in the storage section 30.
Is stored. In the case of the fin 29 in which the storage part 30 is not formed, the fin 29 is dropped on the receiving tray 31 and stored.
The fumes in the lower part of the chamber 2 are cooled and adhere to the cooling plate 23 of the lower fume removing device 21B. Further, the cooling plate 23 and the fins 29 contaminated by the attached fume are taken out of the chamber 2 and cleaned, and then attached to the chamber 2 again. The cooling temperature of the fins 29 is also set in the same manner as previously described capturing Atsumariban 22.

[0024]

As described above, according to the present invention, fume removal method according to the present invention, may be provided to each collection plate each opening formed to the required plurality of positions of chambers, each of these <br / > Each collecting plate is cooled by a cooling device, and the fume generated in the chamber is cooled and adhered by each collecting plate to remove the fume in the chamber, so that the fume is discharged from the chamber to the atmosphere. No and inactive
This has the advantage that the outflow of the reactive gas can be suppressed, the pollution in the atmosphere can be prevented, and the fume can be prevented from adhering to the printed circuit board, the conveyor, the inner wall of the chamber, and the transport mechanism.

Further, fume removal device according to the present invention are respectively openings formed to the required plurality of positions of the chamber, the respective openings of these collecting plate for collecting fumes generated in the chamber and, whereas each collecting plate of these
Since it consists of a cooling device that is detachably attached to each other, fume collection efficiency is good, and since the cooling device can be attached to and detached from the collection plate, cleaning and maintenance management of the collection plate are easy. Further, since the inert gas is not discharged out of the chamber, there is an advantage that the low oxygen atmosphere by the inert gas is stabilized and the productivity of the printed circuit board can be improved.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing one embodiment of the present invention.

FIG. 2 is an enlarged sectional view showing the fume removing device of FIG.

FIG. 3 is a side sectional view showing another embodiment of the present invention.

FIG. 4 is an enlarged sectional view showing the fume removing device of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Soldering apparatus 2 Chamber 3 Printed circuit board 4 Conveyor 7 Preheater 8 Solder tank 9 Opening 21 Fume removing device 21A Upper fume removing device 21B Lower fume removing device 22 Collection plate 26 Cooling device

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masahito Nozue 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd. (72) Inventor Kimihiko Nakamura 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd. (72) Inventor Shunichi Yasuoka 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd. (56) References JP-A-62-240160 (JP, A) Opened 4-13475 (JP, A) Opened 1984-158361 (JP, U) Opened 2-42757 (JP, U) Opened 5-87987 (JP, U) Opened 5-93079 ( JP, U) Hikaru 4-108960 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) H05K 3/32-3/34

Claims (2)

(57) [Claims] In a method for removing fumes in a low-oxygen atmosphere soldering apparatus for soldering to a printed circuit board while maintaining the inside of a chamber in a low-oxygen atmosphere with an inert gas, the chamber is formed at a plurality of required locations in the chamber. each <br/> may be provided each collection plate in the opening, the collection plate of these was cooled by respective cooling device, the fumes generated in said chamber and cooled by the respective collecting plates A method for removing fumes in a low-oxygen atmosphere soldering apparatus, wherein the fumes are removed from the chamber by adhering. 2. A printed circuit board carrying means, a preheating section and a soldering section are provided in the chamber, and soldering is performed on the printed board while maintaining the inside of the chamber in a low oxygen atmosphere by an inert gas. to a fume removal device in a low oxygen atmosphere soldering apparatus, respectively opening to a required plurality of positions of said chamber is formed and this
It consists of a collecting plate for collecting fumes generated in said chamber, for each collecting plate of these with each deposition <br/> cooling device attached detachably to each opening of al A fume removing device in a low oxygen atmosphere soldering device.