JP4786595B2 - Reflow soldering equipment - Google Patents

Description

  The present invention relates to a reflow soldering apparatus including a flux gas removing device that removes a flux gas contained in an atmospheric gas in a furnace.

  In general, the reflow soldering apparatus has a preheating chamber, a reflow chamber, and a cooling chamber in the furnace in order along the conveyor conveyance line, and in each chamber, nitrogen gas or the like is used to prevent oxidation of the soldering portion. Filled with inert gas. The board on which electronic components are mounted is coated with paste-like cream solder at the soldering location. While being transported in the furnace by a conveyor, it is heated to a predetermined high temperature in the preheating chamber and soldered at a high temperature in the reflow chamber. Heated to temperature, the cream solder on the substrate is melted. Then, the molten solder is cooled and solidified while passing through the cooling chamber following the reflow chamber, and the soldering is completed.

  In the reflow soldering process, when the cream solder applied to the substrate is heated, flux, alcohol, and the like contained in the cream solder are evaporated as gas (hereinafter referred to as flux gas). This flux gas liquefies and solidifies (hereinafter simply referred to as liquefaction) when it comes into contact with a wall surface having a low temperature in the furnace and cools, and there is a problem of adhering to the wall surface in the furnace. Further, there is a problem that the flux adhering to the wall surface hangs down and adheres to the substrate.

In order to solve the above problem, the atmosphere gas in the furnace is taken into the cooling device, brought into contact with the surface of the cooling unit of the cooling device to be cooled, and the flux gas contained in the atmosphere gas is liquefied and recovered. A reflow soldering apparatus including a flux recovery apparatus has been proposed (see Patent Document 1). In addition, a plurality of pipes penetrating the cooling chamber and a reflow soldering apparatus that cools atmospheric gas in the cooling chamber by circulating outside air through the pipe have been proposed (see Patent Document 2).
JP-A-5-50218 JP 2003-170291 A

  However, in the above-described flux recovery apparatus, the cleaning operation of the cooling unit to which the flux is attached is difficult, and many man-hours are required for cleaning. Further, in a device in which a pipe penetrates the cooling chamber and the refrigerant flows in one direction through the refrigerant flow path, there is a problem that the number of seal portions between the refrigerant flow path and the cooling chamber increases.

  The problem to be solved by the present invention is to provide a reflow soldering apparatus equipped with a flux gas removing device that can reduce the sealing of the refrigerant flow path. Moreover, it is providing the reflow soldering apparatus provided with the flux gas removal apparatus which can be cleaned easily.

The present invention provides a reflow soldering apparatus including a flux gas removing device configured to cool and remove a flux gas contained in an atmospheric gas in a furnace with a refrigerant flowing through a refrigerant flow path.
The flux gas removing device includes a housing, a cover body that can open and close the open portion of the housing, and a refrigerant flow path forming member that is detachably disposed in the housing,
The casing has a plurality of inner pipes communicating with a refrigerant source.
The refrigerant flow path forming member is supported in the housing and partitions the housing into a flux gas removal chamber and a refrigerant discharge chamber, and a plurality of the standing wall members standing on the partition wall member are closed. An outer pipe,
When the refrigerant flow path forming member is inserted into the housing and the partition wall member is supported in the housing, the outer pipe is disposed so as to cover the outer side of the inner pipe, and the refrigerant inflow passage in the inner pipe is disposed inside. A refrigerant outflow path formed by a gap between the pipe and the outer pipe, and the refrigerant outflow path is configured to communicate with the refrigerant discharge chamber;
The refrigerant is configured to flow out from the refrigerant source through the refrigerant inflow path and the refrigerant outflow path to the refrigerant discharge chamber and return to the refrigerant source.

As the refrigerant, outside air or cooling water is used. An example of the above configuration when the refrigerant is outside air is shown below. That is,
In a reflow soldering apparatus comprising a flux gas removal device configured to cool and remove the flux gas contained in the atmospheric gas in the furnace with the outside air flowing through the outside air flow path,
The flux gas removal device has a housing, a cover body that can open and close the open portion of the housing, and an outside air flow path forming member that is detachably disposed in the housing,
The casing has a plurality of inner pipes communicating with the outside of the casing.
The outside air flow path forming member includes a partition wall member that is supported in the housing and partitions the inside of the housing into a flux gas removal chamber and an outside air discharge chamber, and a plurality of standing wall members standing on the partition wall member. An outer pipe,
The outside air discharge chamber is connected to a suction fan and communicates outside the housing,
When the outside air flow path forming member is inserted into the casing and the partition wall member is supported in the casing, the outer pipe is disposed so as to cover the outer side of the inner pipe, and the outside air inflow path in the inner pipe is located inside. The outside air outflow path is formed by a gap between the pipe and the outer pipe, and the outside air outflow path is configured to communicate with the outside air discharge chamber.

  The cover body and the refrigerant flow path forming member may be configured separately or integrally.

  The flux gas removal device is configured separately from the furnace, and is configured such that an inlet and an outlet of the atmospheric gas in the furnace provided in the flux gas removal chamber of the housing are connected to the furnace, or the flux The gas removal device is integrated with the furnace. When configured separately from the furnace as described above, the atmosphere gas inlet and outlet of the flux gas removal device are either a buffer zone chamber, a preheating chamber, a reflow chamber, or a cooling chamber provided at the inlet or outlet of the furnace. The part is not particularly limited. Moreover, when comprising integrally with a furnace, it is provided so that the buffer zone chamber and cooling chamber provided, for example in the entrance and exit of a furnace may be comprised.

According to the present invention , the refrigerant that has flowed through the refrigerant inflow passage in the inner pipe is folded back through the refrigerant outflow passage outside the inner pipe, so that the refrigerant passage does not take a configuration that penetrates the flux gas removal chamber. . As a result, the seal between the refrigerant flow path and the flux gas removal chamber can be reduced.

Moreover , what is necessary is just to perform as follows, when cleaning a flux gas removal apparatus. That is, when the cover body and the refrigerant flow path forming member are separate bodies, the cover body is opened from the casing, and the refrigerant flow path forming member is taken out of the casing. Can be easily cleaned and cleaned. When the cover body and the refrigerant flow path forming member are integrated, the cover body and the refrigerant flow path forming member can be taken out of the casing together, and can be easily cleaned and cleaned as described above.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In this embodiment, outside air is used as the refrigerant, and the refrigerant source is an outside air atmosphere.

  As shown in FIG. 1, the reflow soldering apparatus includes three preheating chambers 2, one reflow chamber 3, and one cooling chamber 4 in a furnace 1. It has in order along. In each chamber 2, 3, 4, an inert gas, in this embodiment nitrogen gas, is supplied to prevent solder oxidation, and the printed circuit board 6 on which electronic components are mounted is placed in the furnace 1 by the conveyor 5. Be transported. The printed circuit board 6 on which electronic components are mounted has paste-like cream solder applied to the soldering locations.

  7 is a blower, 8 is a motor for driving the blower 7, 9 is a heater, and 10 is a wind guide device. Thus, the hot air circulation device 11 is configured, and the hot air circulation device 11 is provided above and below the preheating chamber 2 and the reflow chamber 3 with the conveyor 5 interposed therebetween. In the cooling chamber 4, cooling air circulation devices 12 are provided above and below the conveyor 5. The cooling air circulation device 12 is different from the hot air circulation device 11 only in that it does not include a heater, and the other configurations are the same.

Therefore, in the preheating chamber 2 and the reflow chamber 3, the atmospheric gas in the furnace 1 heated by the heater 9 is sucked into the blower 7 from the suction port facing the rotation axis direction of the blower 7 and provided in the radial direction of the blower 7. The air is discharged from the discharge port to the air guide device 10, guided by the air guide device 10, and sprayed onto the printed circuit board 6 on the conveyor 5 from a plurality of gas outlets. Thereafter, as described above, the atmospheric gas is sucked from the suction port of the blower 7 and discharged from the discharge port. In this manner, the atmospheric gas is circulated through the chambers 2 and 3 by the hot air circulation device 11 and the printed circuit board 6 is heated. In the cooling chamber 4, atmospheric gas as cooling air circulates in the cooling chamber 4 to cool the printed circuit board 6 on the conveyor.

  Therefore, the printed circuit board 6 on which electronic components are mounted is heated to a predetermined high temperature in the preheating chamber 2 while being conveyed by the conveyor 5, and then heated to a high soldering temperature in the reflow chamber 3 to heat and melt the cream solder. Then, the molten solder is cooled and solidified in the cooling chamber 4, and the electronic component is soldered onto the substrate.

  In the above reflow soldering process, when the cream solder applied to the substrate is heated, the flux, alcohol, etc. contained in the cream solder evaporate as gas. When the atmospheric gas containing the flux gas is cooled in the cooling chamber 4 or the like, the flux gas is liquefied and adheres to the wall surface of the cooling chamber 4 or the printed substrate 6 being conveyed. Therefore, the reflow soldering apparatus includes a flux gas removing device 13 for removing the flux gas contained in the atmospheric gas outside the furnace 1.

  The flux gas removing device 13 will be described with reference to FIGS.

As shown in FIGS. 3 to 5, the flux gas removing device 13 includes a rectangular housing 14 with one surface open, a cover body 15 that can open and close the open portion of the housing 14, and the housing 14. And an outside air flow path forming member 16 detachably disposed therein.

  The housing 14 has a plurality of inner pipes 17 communicating with the outside of the housing 14. The inner pipe 17 is a circular pipe that is open at both ends. One end of the inner pipe 17 is disposed and fixed in an opening formed on one surface of the housing 14, and the distal end extends straight through the housing 14. A plurality of inner pipes 17 are arranged in a zigzag manner at intervals in the longitudinal direction of the housing 14. These inner pipes 17 form an outside air inflow passage 18.

  The outside air flow path forming member 16 has a partition plate 19 that is detachable in the housing 14 and a plurality of outer pipes 20 that are erected on the partition plate 19 and that have their tips closed. The partition plate 19 is an elongated rectangular plate that can be supported via a packing 22 on a rectangular frame-like support plate 21 protruding from the inner surface of the housing 14, and the inside of the housing 14 is filled with a flux gas removal chamber 23. And the outside air discharge chamber 24. The partition plate 19 has a plurality of through holes 25 through which the inner pipe 17 in the housing 14 is inserted.

The outer pipe 20 is a circular pipe with a closed end, and has an inner diameter dimension larger than the outer diameter of the inner pipe 17. One end of the outer pipe 20 is disposed and fixed in the through hole 25 of the partition plate 19, the tip extends straight, and a plurality of plate-like cooling fins 20 a are fixed to the outer peripheral surface. A plurality of outer pipes 20 are arranged in a zigzag manner at intervals in the longitudinal direction of the partition plate 19. The outer pipe 20 is configured to be concentrically disposed on the outer side of the inner pipe 17 in a state where the partition plate 19 is supported by the support plate 21 in the housing 14. In order to increase the heat transfer area, the inner circumference of the outer pipe 20 is more preferably formed in a concavo-convex shape as shown in FIG.

  When the outside air flow path forming member 16 is inserted into the housing 14 and the partition plate 19 is supported by the support plate 21 in the housing 14, the inner peripheral surface and the inner pipe of the outer pipe 20 covered by the inner pipe 17. The gap with the outer peripheral surface of 17 forms the outside air outflow path 26. The outside air outflow path 26 and the outside air inflow path 18 of the inner pipe 17 communicate with each other through a communication space 27 between the front end of the inner pipe 17 and the closed front end of the outer pipe 20. The outside air outflow passage 26 is configured to communicate with the outside air discharge chamber 24 with its lower end opening facing the outside air discharge chamber 24.

  The outside air discharge chamber 24 is connected to a suction fan 28 provided outside the housing 14, and the suction fan 28 is configured to be driven by a motor (not shown).

  Accordingly, when the suction fan 28 is operated, outside air outside the casing 14 flows into the outside air inflow path 18, enters the outside air discharge chamber 24 from the outside air outflow path 26, is sucked by the suction fan 28, and is discharged to the outside atmosphere. Is done.

  An inlet 29 through which atmospheric gas in the furnace 1 flows is provided on one side surface of the flux gas removal chamber 23 of the housing 14, and an outlet 30 is provided on the opposite side surface. As shown in FIG. 2, the inlet 29 and the outlet 30 are connected to, for example, the preheating chamber 2 via pipes 31 and 32, respectively. A circulation fan 33 is provided in the conduit 32 on the outlet 30 side, and the circulation fan 33 is configured to be driven by a motor (not shown). Therefore, when the circulation fan 33 is operated, the atmospheric gas in the preheating chamber 2 is taken into the flux gas removing chamber 23 of the flux gas removing device 13, and the atmospheric gas from which the flux gas has been removed by the flux gas removing device 13 is preheated chamber 2. It is configured to be returned in.

  The cover body 15 is placed on the upper surface of the housing 14 via a packing 34 and can be fixed by lock members 35 respectively attached to both side surfaces of the housing 14.

  A glass window 36 is formed on the side surface of the casing 14 so that the inside can be seen through. A thin plate for rectification 37 having a large number of holes is disposed on the inlet 29 side of the flux gas removal chamber 23.

  Hereinafter, the operation of the reflow soldering apparatus will be described.

  While the printed circuit board 6 on which the electronic components are mounted is conveyed in the furnace 1 by the conveyor 5, the cream solder on the printed circuit board 6 is heated to a predetermined high temperature by the heated atmospheric gas (hot air) circulating in the preheating chamber 2. Then, the molten solder is cooled and solidified by the atmospheric gas (cooling air) circulating in the cooling chamber 4 in the cooling chamber 4 and heated and melted by the heated atmospheric gas (hot air) circulating in the reflow chamber 3. The electronic component is soldered on the substrate.

  When the cream solder applied to the printed circuit board 6 is heated in the preheating chamber 2 and the reflow chamber 3, the flux or alcohol contained in the cream solder evaporates as a gas, and the flux gas is mixed into the atmosphere gas. Is done.

  A part of the atmospheric gas in the preheating chamber 2 flows into the flux gas removal chamber 23 of the flux gas removal device 13 by the operation of the circulation fan 33. On the other hand, in the flux gas removal device 13, the outside air in the outside atmosphere enters the outside air discharge chamber 24 from the outside air inflow path 18 through the outside air outflow path 26 by the operation of the suction fan 28 and is discharged to the outside atmosphere. Therefore, while the atmospheric gas in the preheating chamber 2 passes through the flux gas removal chamber 23, heat exchange is performed with the external air flowing through the outdoor air outflow passage 26, and the atmospheric gas is cooled, so that it is included in the atmospheric gas. The flux gas is liquefied and adheres to the surfaces of the outer pipe 20 and the cooling fin 20a. The atmospheric gas from which the flux gas has been removed flows out of the flux gas removal chamber 23 and is returned to the preheating chamber 2.

  When removing the flux gas, the flux gas removal chamber 23 into which the atmospheric gas in the furnace 1 flows is adjacent to the outside air discharge chamber 24, and the outside air in the outside air discharge chamber 24 is sucked by the suction fan 28 and discharged out of the housing 14. Therefore, the outside air is prevented from flowing into the flux gas removal chamber 23 through the outside air discharge chamber 24. As a result, it is possible to prevent outside air from being mixed into the atmospheric gas, and it is possible to prevent the oxygen concentration of the atmospheric gas in the furnace 1 from fluctuating due to the outside air.

  The flux gas removing device 13 is periodically cleaned. When cleaning the flux gas removing device 13, the outside air flow path forming member 16 can be easily removed from the housing 14 by releasing the lock member 35 and removing the cover body 15 from the housing 14. The taken-out outside air flow path forming member 16 can easily clean the surfaces of the outer pipe 20 and the cooling fin 20a. After cleaning, if the outside air flow path forming member 16 is inserted into the housing 14 and the partition plate 19 is placed on the support plate 21 in the housing 14, the outside air flow path forming member 16 can be easily placed in the housing 14. After that, the cover body 15 is put on the top surface of the housing 14 and can be easily set by locking with the lock member 35.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation is possible in the range which does not deviate from the main point of this invention. For example, although the structure which provided the flux gas removal apparatus in the exterior of the furnace 1 was shown, you may make it comprise a flux gas removal apparatus integrally with a furnace. In this case, for example, a buffer zone chamber (not provided in the above embodiment, but may be provided) provided at the inlet or outlet of the furnace or a cooling chamber is provided.

  Moreover, in the said embodiment, although the front-end | tip of the inner pipe 17 was opened, the front-end | tip of the inner pipe 17 may be obstruct | occluded and a communicating hole may be formed in a front end surface or an outer peripheral surface. Further, although the communication space 27 is provided between the tip of the inner pipe 17 and the tip of the outer pipe 20, the communication space 27 is not provided, and a communication hole may be provided on the outer peripheral surface of the inner pipe 17. .

  The outside air outflow passage 26 is configured to communicate with the outside air discharge chamber 24 with its lower end opening facing the outside air discharge chamber 24, but the size of the through hole 25 is substantially the same as the outer diameter of the inner pipe 17. Alternatively, a communication hole may be formed in the partition plate 19 so that the outside air outflow passage 26 and the outside air discharge chamber 24 communicate with each other.

  Moreover, although the inlet 29 and outlet 30 of the flux gas removal chamber 23 in the flux gas removal apparatus 13 are connected to the preheating chamber 2, buffer zone chambers provided at the furnace inlet and outlet (not provided in the above embodiment, In some cases, it may be provided), or may be connected to the reflow chamber 3 or the cooling chamber 4. Moreover, although the inlet 29 and the outlet 30 of the flux gas removal chamber 23 are connected to the same chamber of the furnace, they may be connected to different chambers.

  Moreover, although the said embodiment demonstrated the case of the air cooling which uses external air as a refrigerant | coolant, it is not limited to this. For example, it is possible to use cooling water as the refrigerant and adopt a water cooling configuration.

  Moreover, although what used nitrogen gas as an atmospheric gas in the furnace 1 was shown, atmospheric gas is not restricted to nitrogen gas. For example, air may be used.

It is a front view which shows the furnace of a reflow soldering apparatus. It is explanatory drawing which shows the connection structure of a furnace and a flux gas removal apparatus. It is front sectional drawing which shows a flux gas removal apparatus. It is a top view which shows the flux gas removal apparatus which removed the cover body. It is side surface sectional drawing which shows a flux gas removal apparatus. It is a cross-sectional view which shows another example of an outer pipe with a cooling fin.

Explanation of symbols

  1 .... Furnace, 2 .... Preheating chamber, 3 .... Reflow chamber, 4 .... Cooling chamber, 5 .... Conveyor, 6 .... Printed circuit board with electronic parts, 7 .... Blower, 8 .... Motor, 9 ..Heater, 10 .. Air guide device, 11 ..Hot air circulation device, 12 ..Cooling air circulation device, 13 ..Flux gas removal device, 14 ..Housing, 15 .. Cover body, 16. Air flow path forming member, 17 ... Inner pipe, 18 ... Outside air inflow passage, 19 ... Partition plate, 20 ... Outer pipe, 20a ... Cooling fin, 21 ... Support plate, 22 ... Packing, 23 ... Flux gas removal chamber, 24..Outside air discharge chamber, 25..Through hole, 26..Outflow passage of outside air, 27..Communication space, 28..Suction fan, 29..Inlet, 30..Outlet, 31,32. ..Pipe line, 33 ... Circulation fan, 34, packing, 35, lock member, 3 ... glass window, 37 ... rectifying thin.

Claims (5)

In a reflow soldering apparatus including a flux gas removing device configured to cool and remove a flux gas contained in an atmospheric gas in a furnace with a refrigerant flowing through a refrigerant flow path,
The flux gas removing device includes a housing, a cover body that can open and close the open portion of the housing, and a refrigerant flow path forming member that is detachably disposed in the housing,
The casing has a plurality of inner pipes communicating with a refrigerant source.
The refrigerant flow path forming member is supported in the housing and partitions the housing into a flux gas removal chamber and a refrigerant discharge chamber, and a plurality of the standing wall members standing on the partition wall member are closed. An outer pipe,
When the refrigerant flow path forming member is inserted into the housing and the partition wall member is supported in the housing, the outer pipe is disposed so as to cover the outer side of the inner pipe, and the refrigerant inflow passage in the inner pipe is disposed inside. A refrigerant outflow path formed by a gap between the pipe and the outer pipe, and the refrigerant outflow path is configured to communicate with the refrigerant discharge chamber;
A reflow soldering apparatus, wherein the refrigerant flows from the refrigerant source through the refrigerant inflow path and the refrigerant outflow path to the refrigerant discharge chamber and returns to the refrigerant source. Reflow soldering apparatus according to claim 1, characterized in that the cover member and the refrigerant flow path forming member is formed separately. Reflow soldering apparatus according to claim 1, wherein the cover member and the refrigerant flow path forming member, characterized in that it is integral. The said flux gas removal apparatus is comprised separately from the furnace, The entrance and exit of the atmospheric gas in the furnace provided in the flux gas removal chamber of the said housing | casing are connected with the furnace. The reflow soldering apparatus according to any one of 1 to 3 . The reflow soldering apparatus according to any one of claims 1 to 3 , wherein the flux gas removing device is configured integrally with a furnace.

Images