WO2010082283A1

WO2010082283A1 - Apparatus and method of recycling resin crystalization flux

Info

Publication number: WO2010082283A1
Application number: PCT/JP2009/007306
Authority: WO
Inventors: サイ文豪; 川上武彦
Original assignee: 株式会社タムラ製作所; 株式会社タムラエフエーシステム
Priority date: 2009-01-16
Filing date: 2009-12-25
Publication date: 2010-07-22
Also published as: CN102281980B; JP5280872B2; JP2010162584A; CN102281980A

Abstract

Provided is an apparatus for recycling resin crystallization flux that has a longer interval of maintenance work and is easy to carry out the maintenance work. A method is also provided. The apparatus includes a chamber having an opening through which gas containing vaporized flux flows from a reflow furnace and a porous member disposed on the inner surface of the chamber wall such that the gas flow is directed toward the porous member.

Description

Resin crystal growth type flux recovery apparatus and flux recovery method

The present invention relates to a flux recovery apparatus that removes a flux component contained in an inert gas in a reflow furnace that heats and solders a circuit board on which electronic components are mounted in an inert gas such as nitrogen. The present invention relates to a flux recovery method.

Currently, SMD (Surface Mounted Device) in which various electronic components are mounted on the surface of a circuit board and soldered is widely used in electronic devices. This soldering is performed using a solder paste. Solder paste is a paste made by mixing cream-like flux and powdered solder. It is applied to the soldering part of the circuit board by printing or a dispenser, etc., and an electronic component is mounted on it. Then, the circuit board and the electronic component are soldered by heating and melting.

The solder paste flux removes the oxide film on the metal surface to be soldered, and prevents the metal surface from being reoxidized by heating during soldering. The flux also acts as a coating material that reduces the surface tension of the solder and improves wetting. In the solder paste flux, solid components such as pine resin, thixotropic agent, and activator are dissolved in a solvent. Therefore, when the solder paste is heated and melted in a reflow furnace, these vaporize and become vapor. This vaporized flux component is liquefied by contact with the low temperature of the reflow furnace, adheres to the circuit board and causes poor soldering, or adheres to the movable part of the reflow furnace and hinders movement. There was a problem.

Therefore, in order to prevent the solder component from adhering on the circuit board from causing poor soldering, when the solder paste is heated and melted in an atmosphere using an inert gas, the atmosphere gas mixed with this flux component is sucked. A reflow furnace is provided with a flux recovery device that recovers a flux component by cooling and liquefying the atmospheric gas.

Some flux collection devices include, for example, a heated atmospheric gas suction mechanism, a heat radiation unit including a plurality of thin pipes serving as cooling units, and a liquid flux collection container. In this flux recovery apparatus, when the sucked atmospheric gas passes through the pipe, it dissipates heat and the flux component is liquefied, and the liquid flux is dropped into the container and recovered. The reason for providing a plurality of thin pipes is to increase the heat radiation efficiency of the atmospheric gas by diverting the heated atmospheric gas to each pipe.

However, in the case of this apparatus, as shown in FIG. 4, the inner wall 42 of the pipe 41 is clean at the beginning of operation, and the liquid flux can be collected smoothly by heat radiation (FIG. 4 (a)). Since the powdery flux 43 adheres to the inner wall 42 of the thin pipe 41 (FIG. 4 (b)), the heat dissipation effect is reduced due to the heat insulating effect of the powdery flux 43 attached to the inner wall 42, and the flux is recovered. There is a problem that becomes insufficient. Further, when the adhesion of the powdery flux 43 further proceeds, the pipe 41 is eventually clogged (FIG. 4C), so the powdery flux 43 attached to the inner wall 42 of the pipe 41 is carefully removed. There is also a problem that complicated maintenance needs to be performed frequently.

In Patent Document 1, a meandering passage is formed inside the flux collection box so that the flux particles collide with the wall surface and adhere easily, and then the flux collection box is cooled to cool the flux. Recovery is described. In this case as well, there is a problem that the meandering passage is immediately clogged with the powdery flux, so that the maintenance cycle is shortened.

The above flux recovery device is an example, and flux devices with various structures are used. However, the basic principle of each is that the flux is liquefied and recovered by removing heat from the atmospheric gas, so the powdery flux adhering to the wall surface of the flux recovery device must be removed frequently. I must.

JP 2003-179341 A

Thus, as a result of various experiments, the inventors have found from the FT / IR measurement that the powdered flux contains melamine, whereas the liquid flux does not contain melamine. The inventors have invented an apparatus that can collect the flux component mixed in the atmospheric gas as a powder at a high temperature and reduce the number of troublesome powder flux removal operations.

In view of the above circumstances, an object of the present invention is to provide a powder flux recovery device and a recovery method that can lengthen the maintenance interval and simplify maintenance work.

A first aspect of the flux recovery apparatus according to the present invention includes an opening into which an atmospheric gas containing a flux in a reflow furnace is injected, and a porous body provided on an inner wall surface where the atmospheric gas collides. It is characterized by providing.

In the first aspect, the flux in the atmosphere gas is collected by causing the atmosphere gas containing the flux to collide with the porous body, thereby accumulating the powdery flux on the surface of the porous body. That is, even if the atmospheric gas containing the flux is not cooled or dissipated and remains at a high temperature, the flux can be recovered from the atmospheric gas in powder form.

Melamine resin may be used as a flame retardant and curing agent for circuit boards and solder resists. Accordingly, at this time, the melamine which is the main component of the melamine resin is also contained in the atmospheric gas containing the flux in the reflow furnace. When the atmospheric gas containing the flux and melamine collides with the porous body provided on the inner wall of the flux recovery device, the kinetic energy of the atmospheric gas is reduced, and first, the melamine nucleus becomes the surface of the porous body. It is thought that it is formed. This is because melamine has a sublimation property, and therefore, when kinetic energy is reduced on the surface of the porous body, the melamine gas directly changes into a solid and easily becomes a core of the powder.

Melamine has the property of dissolving with organic acids such as abietic acid, pimaric acid, and dehydroabietic acid, which are constituents of the flux, so when the melamine nucleus is formed, these organic acid gases are adsorbed on the melamine nucleus. Melamine is further adsorbed on the adsorbed organic acid. In this way, by repeating the adsorption of melamine and the organic acid that is a constituent component of the flux on the porous body surface, the powder consisting of the melamine and the flux component grows around the nucleus of the melamine, The flux component in the atmospheric gas is recovered. The use of the porous body improves the adsorption ability of melamine and organic acid contained in the atmospheric gas in addition to reducing the kinetic energy of the atmospheric gas by utilizing the large specific surface area. Because.

A second aspect of the flux recovery apparatus according to the present invention is characterized in that a flux adsorbent is attached to the porous body. Since the porous body to which the flux adsorbent is attached is used, the flux contained in the atmosphere gas of the reflow furnace is easily adsorbed to the porous body.

A third aspect of the flux recovery apparatus according to the present invention is characterized in that the flux adsorbent is melamine or an alkaline substance. As described above, melamine is a flux adsorbent because it has a property of being soluble with organic acids such as abietic acid, pimaric acid, and dehydroabietic acid, which are constituents of the flux. Alkaline substances capture organic acids by neutralizing with organic acids such as abietic acid, pimaric acid, and dehydroabietic acid, which are constituents of the flux, and the molecular weight of the reaction product increases. Since the force increases and the melting point of the reaction product is higher than that of the organic acid, the alkaline substance becomes an adsorbent that accumulates the flux as powder.

A fourth aspect of the flux collecting apparatus according to the present invention is characterized in that the alkaline substance is a hydroxide.

A fifth aspect of the flux collecting apparatus according to the present invention is characterized in that the inner wall surface is an inner wall surface of the bottom surface. Since the porous body is provided on the inner wall portion of the bottom surface of the flux recovery device, the recovered powdery flux is accumulated from the bottom surface of the flux recovery device.

A sixth aspect of the flux collecting apparatus according to the present invention is characterized by comprising a partition plate in which the flow path of the injected atmospheric gas is formed. The internal space of the flux recovery device is partitioned by a partition plate, and the partition plate is provided with a hole serving as an atmosphere gas flow path.

A first aspect of the flux recovery method according to the present invention includes a step of injecting an atmosphere gas containing a flux in a reflow furnace into a flux recovery device, and the atmosphere gas is provided with a porous body. And a step of colliding with the inner wall surface of the recovery device. In the first aspect, in the step of causing the atmospheric gas containing the flux to collide with the porous body, the powdery flux is accumulated on the surface of the porous body, and the flux in the atmospheric gas is recovered.

A second aspect of the flux recovery method according to the present invention is characterized in that a flux adsorbent is attached to the porous body. A third aspect of the flux recovery method according to the present invention is characterized in that the flux adsorbent is melamine or an alkaline substance. A fourth aspect of the flux recovery method according to the present invention is characterized in that the alkaline substance is a hydroxide. According to a fifth aspect of the flux collection method of the present invention, the inner wall surface is an inner wall surface of the bottom surface. A sixth aspect of the flux recovery method according to the present invention is characterized by comprising a partition plate in which the flow path of the injected atmospheric gas is formed.

According to the first aspect of the flux recovery apparatus according to the present invention and the first aspect of the flux recovery method according to the present invention, by colliding the atmospheric gas containing the flux with the porous body, Since the powdery flux is accumulated on the surface, the accumulation part of the powdery flux can be appropriately selected, and the flow path of the atmospheric gas can be prevented from being clogged with the powdery flux. Further, since the powdery flux can be prevented from clogging the flow path, the maintenance cycle of the flux collecting apparatus can be greatly extended, and thus the production efficiency is improved.

Furthermore, since flux can be collected without cooling or radiating the flux, the flux collection efficiency can be maintained regardless of whether the flux adheres to the flow path wall surface, and the atmospheric gas after removing the flux component with a small amount of energy Can be reheated and the production cost can be reduced. In addition, when the melamine is contained in the atmospheric gas, the flux is recovered by repeating adsorption of melamine and organic acid, which is a constituent of the flux, on the porous body surface. At this time, the flux adhering to the inner wall may not be sufficiently wiped off, maintenance is simple, and workability is improved.

According to the second aspect of the flux recovery apparatus according to the present invention and the second aspect of the flux recovery method according to the present invention, since the flux adsorbent is attached to the porous body, the atmospheric gas in the reflow furnace Even if melamine is not mixed in, the powdery flux can be accumulated in the porous body.

According to the third aspect of the flux recovery apparatus according to the present invention and the third aspect of the flux recovery method according to the present invention, since the flux adsorbent is melamine or an alkaline substance, it has an excellent ability to adsorb powdery flux. Yes.

According to the 4th aspect of the flux collection | recovery apparatus which concerns on this invention, and the 4th aspect of the flux collection | recovery method which concerns on this invention, since an alkaline substance is a hydroxide, in addition to a neutralization reaction, a hydrogen bond with an organic acid Thus, the powder can be efficiently grown. Further, since the hydroxide is inexpensive and easily available, the production cost can be suppressed.

According to the fifth aspect of the flux recovery apparatus according to the present invention and the fifth aspect of the flux recovery method according to the present invention, since the porous body is provided on the inner wall surface of the bottom surface, the bottom of the flux recovery apparatus As a result, powder flux is accumulated on the surface, and it is easy to secure a flow path for the atmospheric gas.

According to the sixth aspect of the flux recovery apparatus according to the present invention and the sixth aspect of the flux recovery method according to the present invention, the interior of the flux recovery apparatus is partitioned by a partition plate, and the partition plate contains atmospheric gas. Since the holes serving as the flow paths are provided, the flow of the atmospheric gas is dispersed and collides with the porous body, so that the uneven distribution of the powder flux collecting portion can be suppressed. In addition, since the uneven distribution of the powdery flux can be suppressed, clogging of the flow path of the atmospheric gas with the powdery flux can be suppressed. Furthermore, by adjusting the height of the hole serving as the flow path, the accumulation capacity of the powdery flux can be changed, and the maintenance cycle can be adjusted.

It is a schematic sectional drawing of the flux collection | recovery apparatus concerning the example of 1st Embodiment of this invention. It is a schematic sectional drawing of the flux collection | recovery apparatus concerning the example of 2nd Embodiment of this invention. It is a conceptual diagram which shows a mode that a powdery flux is formed centering on melamine. It is a conceptual diagram which shows a mode that the conventional flux collection | recovery apparatus is clogged with powdery flux.

1, 21

Flux recovery device

4, 24

Stainless wool

5, 25 Vertical partition plate 6, 26 Hole 7 Atmospheric gas 11 Fan 12 Melamine 13 Organic acid 31 Injecting opening 32 Discharging opening

Next, a flux recovery apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view of a flux recovery apparatus according to a first embodiment of the present invention, FIG. 2 is a schematic cross-sectional view of a flux recovery apparatus according to a second embodiment of the present invention, and FIG. It is a conceptual diagram which shows a mode that a powdery flux is formed using a nucleus.

The flux recovery apparatus 21 according to the first embodiment of the present invention includes a container portion 22 and a lid portion 23 as shown in FIG. The container part 22 includes a rectangular bottom part 29 and four side wall parts 30 erected from each side of the bottom part 29, and is used by sealing the upper side of the container part 22 with a lid part 23.

The lid 23 is provided with an injection opening 31 that is an inlet for the high-temperature atmospheric gas 7 mixed with the flux component, and a discharge opening 32 that is an outlet for the atmospheric gas 7 from which the flux component has been removed. ing. Therefore, the flow 8 of the injected atmospheric gas 7 has a structure in which it first collides with the stainless wool 24 without passing through the bent flow path. In this embodiment, by using a suction device (not shown) such as a blower unit, the atmosphere gas 7 is injected into the flux recovery device 21 from a reflow furnace (not shown), and further from the flux recovery device 21. Atmospheric gas 7 is discharged.

The container part 22 has a stainless steel wool 24, which is a porous body, laid on the inner wall surface of the bottom part 29, and a vertical partition plate 25 partitions the inside of the flux recovery apparatus 21 into a plurality of spaces. The vertical partition plate 25 is provided with a hole 26 and serves as a flow path for the atmospheric gas 7 sucked from the reflow furnace. The hole 26 is provided at a different height from the hole 26 provided in the adjacent vertical partition plate 25. Therefore, the flow 8 of the atmospheric gas 7 that has passed through the hole 26 collides with the next partition plate 25 in the vertical direction, a part of which is divided, and collides with the stainless wool 24 laid on the bottom 29. The flow 8 of the atmospheric gas 7 that collides with the stainless wool 24 is reversed after the collision and passes through the hole 26 of the vertical partition plate 25 that collided.

In the first embodiment, three vertical partition plates 25 are erected from the bottom 29, and the bottom 29 on which the stainless wool 24 is laid is partitioned into four sections. At each vertical partition plate 25, the flow 8 of the atmospheric gas 7 collides and a part of the flow 8 collides with the stainless steel wool 24 on the bottom 29, so that the atmospheric gas 7 is substantially uniform on the stainless steel wool 24. collide. Each of the vertical partition plates 25 has the same height as the side wall portion 30, and comes into contact with the inner wall of the lid portion 23 when the lid portion 23 is placed on the container portion 22. .

Further, the bottom portion 29 of the container portion 22 is provided with the fan 11 so that the stainless wool 24 can be cooled as required.

When the flow 8 of the atmospheric gas 7 collides with the stainless wool 24, the kinetic energy of the atmospheric gas 7 is reduced due to the large specific surface area of the stainless wool 24. Then, as shown in FIG. 3, first, the melamine 12 derived from the circuit board contained in the atmospheric gas 7 forms a nucleus on the surface of the stainless wool 24. This is because melamine 12 has sublimability, and therefore, when kinetic energy is reduced, gaseous melamine 12 directly changes into a solid and becomes the core of the powder even at a high temperature. Furthermore, since melamine 12 has a property of dissolving with organic acids 13 such as abietic acid, pimaric acid, dehydroabietic acid and the like, which are constituents of the flux, when the nucleus of melamine 12 is formed, the gas of organic acid 13 becomes melamine. Adsorbed on 12 nuclei. Further, another melamine 12 is adsorbed on the adsorbed organic acid 13 and a powder having a flux component grows.

As described above, the flux component in the atmosphere gas 7 is accumulated as a powder around the nucleus of the melamine 12 on the surface of the stainless wool 24, so that the flux component is powdered without cooling the atmosphere gas 7. Can be recovered as At this time, the removal of the powdery flux is continued until the powdery flux accumulated on the stainless wool 24 blocks the hole 26 provided at the lowermost part of the holes 26 of the vertical partition plate 25. You don't have to.

Next, the flux collection apparatus 1 according to the second embodiment of the present invention will be described. As shown in FIG. 2, the flux recovery apparatus 1 is composed of a container part 2 and a lid part 3. The container part 2 includes a rectangular bottom part 9 and four side wall parts 10 erected from each side of the bottom part 9, and is used by sealing the upper side of the container part 2 with a lid part 3.

The side wall 10 of the container 2 has an injection opening (not shown) that is an inlet for the high-temperature atmosphere gas 7 mixed with the flux component, and an outlet for the atmosphere gas 7 from which the flux component has been removed. A discharge opening (not shown) is provided.

In this embodiment as well, by using a suction device (not shown) such as a blower unit, the atmosphere gas 7 is injected into the flux recovery device 1 from a reflow furnace (not shown), and further from the flux recovery device 1. Atmospheric gas 7 is discharged.

The container part 2 is laid with a porous stainless steel wool 4 on the inner wall surface of the bottom 9 thereof, and a vertical partition plate 5 partitions the inside of the flux recovery apparatus 1 into a plurality of spaces. The vertical partition plate 5 is provided with a hole 6 and serves as a flow path for the atmospheric gas 7 sucked from the reflow furnace. The hole 6 is provided at a different height from the hole 6 provided in the adjacent vertical partition 5. Therefore, the flow 8 of the atmospheric gas 7 that has passed through the hole 6 collides with the next partition plate 5 in the vertical direction, a part of which is divided, and collides with the stainless wool 4 laid on the bottom 9. The flow 8 of the atmospheric gas 7 colliding with the stainless wool 4 is reversed after the collision and passes through the hole 6 of the vertical partition plate 5 which collided.

In the second embodiment, five vertical partition plates 5 are erected from the bottom 9, and the bottom 9 on which the stainless wool 4 is laid is partitioned into six sections. At each vertical partition plate 5, the flow 8 of the atmospheric gas 7 collides and a part of the flow 8 collides with the stainless steel wool 4 on the bottom 9, so that the atmospheric gas 7 is almost uniform on the stainless steel wool 4. collide. In addition, a horizontal partition plate 5 ′ is installed on the upper end open portion of the vertical partition plate 5, and a flow path for guiding the atmospheric gas 7 sucked from the reflow furnace to collide with the stainless wool 4 is provided. Forming.

Furthermore, the bottom 9 of the container 2 is provided with a fan 11 so that the stainless wool 4 can be cooled as required.

Next, a method for using the flux recovery apparatus according to the present invention will be described. The

flux recovery apparatuses

1 and 21 are separate from the reflow furnace, and are provided so as to be connectable to the heating chamber of the reflow furnace. An opening for injection of the

flux recovery devices

1 and 21 is attached to the end of the forward path (not shown) of the atmospheric gas 7 extended from the heating chamber of the reflow furnace, and the return path (not shown) of the atmospheric gas 7 is attached. The discharge openings of the

flux collecting apparatuses

1 and 21 are attached in communication with the end of What is necessary is just to select the attachment quantity of the flux collection |

recovery apparatuses

1 and 21 suitably according to the atmospheric gas amount of a reflow furnace.

At the beginning of use of the

flux recovery devices

1 and 21, not only the kinetic energy of the atmosphere gas 7 is reduced by using the large specific surface area of the

stainless wool

4 and 24 in order to facilitate the formation of the nucleus of the melamine 12, If necessary, the fan 11 may be operated to cool the

stainless wool

4 and 24, and the kinetic energy of the atmospheric gas 7 may be further reduced. When the melamine 12 nuclei are formed on the

stainless wool

4, 24, the flux component organic acid 13 is adsorbed on the melamine 12 nuclei, and the melamine 12 is further adsorbed on the adsorbed organic acid 13. Flux can be recovered by simply reducing the kinetic energy due to a collision without operating. Moreover, since the collision of the atmospheric gas 7 on the

stainless wool

4 and 24 can be made uniform by the

vertical partition plates

5 and 25, uneven distribution of the powdery flux can be suppressed, and the flux collecting ability can be improved.

In the

flux collecting apparatuses

1 and 21 according to the present invention, the maintenance of the removal of the powdery flux is performed until the powdery flux blocks the holes 6 and 26 at the bottom and the flow 8 of the atmospheric gas 7 is stagnated. You don't have to. Further, when removing the powdery flux accumulated on the

bottoms

9 and 29, if the melamine 12 nucleus and the organic acid 13 are left on the surfaces of the

stainless wool

4 and 24, then the

flux recovery devices

1 and 21 are connected. When restarting, the remaining melamine 12 and the organic acid 13 are used as a foothold to facilitate the growth of the powdery flux and improve the flux recovery efficiency. Therefore, it is not necessary to carefully remove the flux.

Next, another embodiment of the present invention will be described. In the above embodiment, the

stainless wools

4 and 24 are used as they are, but a flux adsorbent may be added to the

stainless wools

4 and 24 in advance. The flux adsorbent may be a substance having a function of adsorbing flux, and melamine is preferable from the viewpoint of adsorptivity with an organic acid that is a flux component. In addition, the flux adsorbent is also preferably an alkaline substance from the viewpoint of reactivity with the flux component, and in particular, in addition to the reactivity, the powder can be efficiently grown by hydrogen bonding with an organic acid. Hydroxides are preferred. Moreover, in the said embodiment, although

stainless wool

4 and 24 was used for the porous body, if it has a large specific surface area, it will not specifically limit, A particulate and powdery porous body may be sufficient.

In the above embodiment, the

stainless wools

4 and 24 are provided on the

bottoms

9 and 29. Instead, the side walls are formed according to the structure of the

flux recovery devices

1 and 21 and the position of the opening for injecting the atmospheric gas 7. 10 and 30 may be provided. Furthermore, in the first embodiment, there are three vertical partition plates 25, and in the second embodiment, there are five vertical partition plates 5, but the number of

partition plates

5, 25 is It can be selected as appropriate. In the above embodiment, the holes 6 and 26 provided in the adjacent

vertical partition plates

5 and 25 have different heights, but the positions of the holes 6 and 26 are shifted in the horizontal direction. The atmospheric gas 7 may collide with the

vertical partition plates

5 and 25, and the height 8 and the horizontal position are made the same so that the flow 8 of the atmospheric gas 7 is forced to the

vertical partition plates

5 and 25. It is not necessary to make it collide. The position, number, and size of the holes 6 and 26 may be appropriately selected according to the flow rate of the atmospheric gas 7 and the like. In particular, by adjusting the heights of the holes 6 and 26 which are the lowermost parts, the collection capacity of the

flux collection devices

1 and 21 can be changed, and thus the maintenance period can be adjusted. In the above embodiment, the fan 11 is provided to further reduce the kinetic energy of the atmospheric gas 7, but the fan 11 may not be provided.

A flux recovery experiment was performed using the flux recovery apparatus according to the first embodiment described above. The dimensions of the flux recovery device of the present invention are 100 mm in length, 600 mm in width, and 400 mm in height. Of the holes provided in the partition plate in the vertical direction, the hole located at the bottom is 50 mm from the bottom inner wall. did. Moreover, the magnitude | size of the hole part was 100 mm x 50 mm, respectively. Further, stainless wool (made by WY Spring Co., Ltd., trade name: Demister) was laid on the entire inner surface of the bottom surface of the flux collecting apparatus. The container part and lid part of the flux recovery apparatus were made of stainless steel. Three of these flux recovery devices were connected in parallel to a reflow furnace, and a blower unit was used for suction of atmospheric gas from the reflow furnace. It should be noted that the fan installed at the bottom of the flux recovery apparatus was operated until 6 hours after the start of operation, and then the fan was stopped.

The operation period of the reflow furnace was 8 weeks, and 60,000 circuit boards were soldered. In this case, since 2 g of solder paste is used per circuit board, 120 kg of solder paste is heated and melted in 8 weeks.

As a result, there was no circuit board on which the flux component adhered and caused poor soldering. In addition, the powdery flux was on average about 10 mm on the stainless wool, and the bottom hole was not clogged and the atmosphere gas flow path was secured. Therefore, the operation of removing the powdery flux is unnecessary and the operation can be continued.

Next, a comparative experiment was performed using a conventional flux recovery apparatus (a type that dissipates atmospheric gas using a plurality of pipes). The heat radiating portion of the flux collecting apparatus was composed of four stainless steel pipes having an inner diameter of 35 mm and a length of 120 mm. Seven of these flux recovery devices were connected to a reflow furnace in parallel. A blower unit was used for the suction of atmospheric gas from the reflow furnace.

The operation period of the reflow furnace was one week, and 75,500 circuit boards were soldered. In this case, since 2 g of solder paste is used per circuit board, 15 kg of solder paste is heated and melted in one week.

As a result, there was no circuit board in which the flux component adhered and caused poor soldering, but each stainless steel pipe was clogged with powdery flux. Therefore, no further operation was possible unless the reflow furnace was stopped and the powder flux was removed.

As described above, the flux recovery apparatus according to the present invention was able to extend the maintenance cycle by 8 times or more compared with the conventional product.

The flux recovery device according to the present invention can greatly extend the maintenance cycle by preventing the flow path of the atmospheric gas from being clogged with the powdery flux. High utility value in the field of circuit board soldering.

Claims

An opening into which atmospheric gas containing flux in the reflow furnace is injected;
And a porous body provided on an inner wall surface with which the atmospheric gas collides.
The flux recovery apparatus according to claim 1, wherein a flux adsorbent is attached to the porous body.
The flux recovery apparatus according to claim 2, wherein the flux adsorbent is melamine or an alkaline substance.
The flux recovery apparatus according to claim 3, wherein the alkaline substance is a hydroxide.
The flux recovery apparatus according to claim 1, wherein the inner wall surface is an inner wall surface of a bottom surface.
The flux recovery apparatus according to claim 1, further comprising a partition plate in which the flow path of the injected atmospheric gas is formed.
Injecting the atmospheric gas containing the flux in the reflow furnace into the flux recovery device;
And a step of causing the atmospheric gas to collide with an inner wall surface of the flux recovery device provided with a porous body.
The flux recovery method according to claim 7, wherein a flux adsorbent is attached to the porous body.
9. The flux recovery method according to claim 8, wherein the flux adsorbent is melamine or an alkaline substance.
The flux recovery apparatus according to claim 9, wherein the alkaline substance is a hydroxide.
The flux collecting method according to claim 7, wherein the inner wall surface is an inner wall surface of a bottom surface.
The flux recovery method according to claim 7, further comprising a partition plate in which the flow path of the injected atmospheric gas is formed.