JP2007109841A - Method of cleaning reflow-soldering device, and reflow-soldering device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To remove adhered flux or flux decomposition products in the furnace of a reflow-soldering device. <P>SOLUTION: The reflow-soldering device for soldering by heating while conveying a printed circuit substrate 6 mounted with electronic components by using a conveyor 5 includes: a cleaning fluid tank 21 for storing the cleaning fluid; cleaning fluid injection devices 13 and 20 which can inject the cleaning fluid in the cleaning fluid tank 21 into a furnace 1; and an outlet 23 for discharging out of the furnace 1 the cleaning fluid after washing out the adhered flux and the flux decomposition products in the furnace 1 with the cleaning fluid injected into the furnace 1. The cleaning fluid, which passes along a discharging pipe 24 from the outlet 23, is collected by the cleaning fluid tank 21. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a cleaning method for removing flux and flux decomposition products adhering to a furnace of a reflow soldering apparatus, and a reflow soldering apparatus.

  In general, a reflow soldering apparatus has a preheating chamber, a reflow chamber, and a cooling chamber in order in a furnace along a conveyor conveyance line, and a substrate on which electronic components are mounted is conveyed in the furnace by the conveyor. The board on which the electronic components are mounted is coated with paste-like cream solder at the soldering location, heated to a predetermined high temperature in the preheating chamber, and heated to a high soldering temperature in the reflow chamber. Cream solder 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, the flux, alcohol, etc. contained in the cream solder are evaporated as gas. When this flux gas is cooled, it liquefies or solidifies, and there is a problem that the flux and flux decomposition products adhere to the wall surface of the cooling chamber or the like in the furnace. Further, the flux or flux decomposition product that has adhered to the wall surface or the like may fall and adhere to the substrate.

In order to solve these problems, a reflow soldering apparatus including a flux recovery apparatus that cools a high-temperature atmosphere gas in a furnace and liquefies and recovers a flux gas contained in the atmosphere gas has been proposed. .
Japanese Patent No. 2794352

  The problem to be solved by the present invention is to remove flux and flux decomposition products adhering to the furnace of the reflow soldering apparatus.

  The present invention relates to a cleaning method for a reflow soldering apparatus that heats and solders a substrate on which an electronic component is mounted while being transported by a transport means, and removes the flux adhered to the furnace or a flux decomposition product by spraying the cleaning liquid. It is characterized by that. The cleaning liquid is sprayed manually or automatically.

  The present invention relates to a cleaning method of a reflow soldering apparatus that heats and solders a substrate on which electronic components are mounted while being transported by a transport means, while spraying a cleaning liquid onto flux or flux decomposition products adhered to the furnace, And the adhesion surface of the flux decomposition product is cleaned with a cleaning member. The spraying of the cleaning liquid and the cleaning with the cleaning member are performed manually or automatically.

  The present invention relates to a reflow soldering apparatus that heats and solders a substrate on which electronic components are mounted while being transported by a transport means, and discharges the cleaning liquid after washing off the flux and flux decomposition products adhering to the furnace. It is characterized by having a discharge port.

  The present invention is characterized in that, in the above reflow soldering apparatus, the discharge port is also a discharge port for liquefied flux.

  The present invention provides a reflow soldering apparatus that heats and solders a substrate on which electronic components are mounted while being transported by a transport means, and includes a cleaning device that cleans off flux and flux decomposition products adhering to the furnace using a cleaning liquid. It is characterized by that.

  The present invention provides a reflow soldering apparatus that heats and solders a substrate on which an electronic component is mounted while being transported by a transport means, and includes a cleaning device that sprays and removes flux and flux decomposition products adhering to the furnace. It is characterized by that.

  The present invention relates to a reflow soldering apparatus that heats and solders a substrate on which an electronic component is mounted while being conveyed by a conveying means, and a cleaning liquid tank in which the cleaning liquid is stored, and a cleaning liquid that can inject the cleaning liquid in the cleaning liquid tank into the furnace And an injection device.

The present invention is characterized in that, in the above apparatus, the furnace is provided with a discharge port.

  The cleaning liquid after cleaning is preferably configured to be collected in a cleaning liquid tank.

  The cleaning liquid injection device includes, for example, a liquid supply pump and a cleaning liquid injection pipe connected to the liquid supply pump and disposed in the furnace, and the cleaning liquid in the cleaning liquid tank is sent to the cleaning liquid injection pipe by the liquid supply pump, and the cleaning liquid It is comprised so that a washing | cleaning liquid may be injected from the injection hole currently formed in the injection pipe.

  In addition to the above-described configuration, the present invention further includes a cleaning means in which a cleaning member is disposed in the furnace, and the cleaning member moves along the adhesion surface of the flux and flux decomposition product in the furnace to cause the flux and flux decomposition. It is preferable to be configured to remove objects.

  More preferably, the present invention is configured such that the cleaning member moves while rotating along the adhesion surface of the flux and flux decomposition product in the furnace to remove the flux and flux decomposition product.

  The cleaning member has an outer surface portion formed of hair, sponge, cloth, or the like.

  Flux and flux decomposition products adhering to the furnace of the reflow soldering apparatus are washed away using a cleaning liquid. For example, flux and flux decomposition products adhered in the furnace are washed away by the cleaning liquid sprayed from the cleaning liquid spraying device. If the cleaning means is further provided in addition to the cleaning liquid ejecting apparatus, the cleaning liquid is ejected from the cleaning liquid ejecting apparatus at the time of cleaning, and the cleaning member moves or rotates on the surface where the flux or flux decomposition product is attached. Flux and flux decomposition products are washed away by moving. The cleaning liquid after washing off the flux and flux decomposition product is discharged out of the furnace, for example, from an outlet provided in the furnace.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

  In the reflow soldering apparatus, the furnace 1 has three preheating chambers 2, one reflow chamber 3, and one cooling chamber 4 in order along the transfer line of the conveyor 5. In each chamber 2, 3, 4, nitrogen gas is supplied to prevent oxidation of the solder, and a printed circuit board 6 on which electronic components are mounted is conveyed through the furnace 1 by the conveyor 5. The printed circuit board 6 on which the electronic component is mounted has paste-like cream solder applied to the soldering portion. After being heated to a predetermined temperature in the preheating chamber 2, the cream solder is heated and melted in the reflow chamber 3 and cooled. The molten solder is cooled and solidified in the chamber 4, and the electronic component is soldered onto the substrate.

  In the preheating chamber 2 and the reflow chamber 3, hot air circulation devices 7 are provided up and down across the conveyor 5. Hereinafter, although the apparatus of the upper side of the conveyor 5 is demonstrated, the lower side is also the same. A blower 8 is provided at the top of each chamber 2, 3 and is connected to a motor 9 installed on the upper surface of the furnace 1. The blower 8 has a suction port at the center of the lower surface and a discharge port at the outer periphery, and is housed in the air guide casing 10. A suction port is opened on a surface of the air guide casing 10 facing the suction port of the blower 8. Nitrogen gas discharged from the discharge port of the blower 8 is guided to the wind guide casing 10 and rectified inside, and printed on the conveyor 5 from a plurality of gas outlets 11 provided on the lower surface facing the conveyor 5 side. It blows out toward the board | substrate 6, and is suck | inhaled from the suction inlet of the air blower 8, and is discharged from a discharge outlet after that. In this way, nitrogen gas circulates in the chambers 2 and 3, and the nitrogen gas is heated by a heater (not shown) provided in the middle of the circulation path, so the printed circuit board 6 is heated. .

  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 7 only in that it does not include a heater, and the other configurations are the same. Therefore, nitrogen gas as cooling air circulates in the cooling chamber 4 and cools the printed circuit board 6 on the conveyor.

  In the space between the upper and lower hot air circulation devices 7 and the upper and lower cooling air circulation devices 12 in the furnace 1, a plurality of cleaning liquid injection tubes 13 are provided at appropriate intervals. The cleaning liquid injection pipe 13 is horizontally and linearly arranged in a direction perpendicular to the conveying line of the conveyor 5 and has a large number of cleaning liquid injection holes on the upper surface.

  One end of the cleaning liquid injection pipe 13 is closed, the other end penetrates the furnace 1 and protrudes from the measuring portion of the furnace 1, and one end of the connection pipe 14 is connected to the protruding end portion. The other end of the connecting pipe 14 connected to the cleaning liquid injection pipe 13 is connected to a distribution pipe 15 disposed outside the furnace 1. The distribution pipes 15 are respectively provided on the inlet side and the outlet side of the furnace 1, the plurality of connection pipes 14 near the inlet are connected to the distribution pipe 15 on the inlet side, and the plurality of connection pipes 14 near the outlet are on the outlet side. Each is connected to a distribution pipe 15. A switching valve 17 is connected to each of the distribution pipes 15 on the inlet side and the outlet side via connecting pipes 16. The inlet side and outlet side switching valves 17 are connected to each other by a connecting pipe 18.

  A distribution pipe 19 is provided near the outlet side switching valve 17 of the connection pipe 18, and the discharge side of the liquid supply pump 20 is connected to the distribution pipe 19. The suction side of the feed pump 20 is connected to a discharge port of a cleaning liquid tank 21 provided outside the furnace 1 by a connecting pipe 22. A cleaning liquid discharge port 23 is provided at the bottom of each chamber 2, 3, 4. One end of a discharge pipe 24 is connected to the discharge port 23, and the other end of the discharge pipe 24 is inserted into the cleaning liquid tank 21. Yes. The bottom inner surfaces of the chambers 2, 3, 4 are formed in an inclined surface toward the discharge port 23.

  The switching valve 17 on the inlet side and the outlet side is connected to each other by a connecting pipe 25 in addition to the connecting pipe 18, and a nitrogen gas supply pipe 26 is located near the inlet side switching valve 15 of the connecting pipe 25. Is connected.

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

  While the printed circuit board 6 mounted with electronic components is conveyed in the furnace 1 by the conveyor 5, the cream solder on the printed circuit board 6 is heated to a predetermined temperature by hot air (nitrogen gas) circulating in the preheating chamber 2, Further, the molten solder is heated and melted by hot air (nitrogen gas) circulating in the reflow chamber 3, and the molten solder is cooled and solidified by cooling air (nitrogen gas) circulating in the cooling chamber 4 in the cooling chamber 4. Soldered.

  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 nitrogen gas. Is done. When the flux gas in the nitrogen gas is cooled, it is liquefied or solidified, and the flux and flux decomposition products adhere to the wall surfaces of the chambers 2, 3, 4 (especially the cooling chamber 4) and the wall surface of the wind guide casing 10. However, the chambers 2, 3 and 4 (especially the cooling chamber 4) gradually become dirty with flux and flux decomposition products. Therefore, it is necessary to periodically clean the inside of the furnace 1. Next, the cleaning operation in the furnace 1 will be described.

  When cleaning the inside of the furnace 1, the feed pump 20 is driven. By driving the liquid supply pump 20, the cleaning liquid in the cleaning liquid tank 21 flows from the distribution pipe 15 into each cleaning liquid injection pipe 13, and the cleaning liquid is discharged from the injection holes of each cleaning liquid injection pipe 13 into the preheating chamber 2, the reflow chamber 3, and the cooling. The flux and flux decomposition products injected into the chamber 4 and adhered to the chambers 2, 3, and 4 are washed away. The cleaning liquid from which the flux and flux decomposition products have been removed is returned to the cleaning liquid tank 21 through the discharge pipe 24 from the discharge port 23 at the bottom of each chamber 2, 3, 4. The above is repeated, and the flux and flux decomposition products in the furnace 1 are removed.

  When the cleaning operation is performed for a predetermined time, the liquid supply pump 20 is stopped. Thereafter, the switching valve 17 is switched, and nitrogen gas is supplied from a nitrogen gas supply source (not shown) through the supply pipe 26 and ejected from the cleaning liquid injection pipe 13, whereby the distribution pipe 15 and the connection pipes 14, 16. , And the cleaning liquid remaining in the cleaning liquid jet pipe 13 and the cleaning liquid adhering to the chambers 2, 3, 4 are removed and returned to the cleaning liquid tank 21.

  4-5 illustrate another embodiment of the present invention. In the above-described embodiment, the cleaning liquid injection pipe 13 is disposed at right angles to the conveyance line of the conveyor 5. In this embodiment, the cleaning liquid injection pipe is provided along the conveyance line of the conveyor 5.

  In the space between the upper and lower hot air circulation devices 7 and the upper and lower cooling air circulation devices 12 in the furnace 1, a pair of cleaning liquid injection pipes 13 are provided at an appropriate interval. The cleaning liquid injection pipe 13 is disposed so as to extend horizontally in the preheating chamber 2, the reflow chamber 3, and the cooling chamber 4 along the conveying line of the conveyor 5, and has a large number of cleaning liquid injection holes on the upper surface.

  Both ends of the cleaning liquid injection pipe 13 pass through the furnace 1 and protrude from the measuring section of the furnace, and one end of a connection pipe 27 is connected to each of the protruding ends. The other ends of the pair of connecting pipes 27 connected to both ends of the cleaning liquid injection pipe 13 are respectively connected to a pair of switching valves 17 disposed outside the furnace 1. A pair of switching valves 17 arranged on the inlet side and the outlet side of the furnace 1 are connected to each other by a connecting pipe 18.

  A distribution pipe 19 is provided near the outlet side switching valve 17 of the connection pipe 18, and the discharge side of the liquid supply pump 20 is connected to the distribution pipe 19. The suction side of the feed pump 20 is connected to a discharge port of a cleaning liquid tank 21 provided outside the furnace 1 by a connecting pipe 22. A cleaning liquid discharge port 23 is provided at the bottom of each chamber 2, 3, 4. One end of a discharge pipe 24 is connected to the discharge port 23, and the other end of the discharge pipe 24 is inserted into the cleaning liquid tank 21. Yes. The bottom inner surfaces of the chambers 2, 3, 4 are formed in an inclined surface toward the discharge port 23.

  The switching valve 17 on the inlet side and the outlet side is connected to each other by a connecting pipe 25 in addition to the connecting pipe 18, and a nitrogen gas supply pipe 26 is located near the inlet side switching valve 15 of the connecting pipe 25. Is connected.

  Since the configuration other than the above configuration is the same as that of the above-described embodiment, the cleaning operation will be described below.

  When cleaning the inside of the furnace 1, the feed pump 20 is driven. By driving the liquid supply pump 20, the cleaning liquid in the cleaning liquid tank 21 flows from the distribution pipe 19 into the pair of cleaning liquid injection pipes 13, and the cleaning liquid is injected from the injection holes of the cleaning liquid injection pipes 13 into the preheating chamber 2, the reflow chamber 3, and The flux and flux decomposition products that are injected into the cooling chamber 4 and adhered to the chambers 2, 3, and 4 are washed away. The cleaning liquid from which the flux and flux decomposition products have been removed is returned to the cleaning liquid tank 21 through the discharge pipe 24 from the discharge port 23 at the bottom of each chamber 2, 3, 4. The above is repeated, and the flux and flux decomposition products in the furnace 1 are removed.

  When the cleaning operation is performed for a predetermined time, the liquid supply pump 20 is stopped. Thereafter, the switching valve 17 is switched, and nitrogen gas is supplied from a nitrogen gas supply source (not shown) through the supply pipe 26 and ejected from the cleaning liquid injection pipe 13. The cleaning liquid remaining in the chamber and the cleaning liquid adhering to the chambers 2, 3, 4 are removed and returned to the cleaning liquid tank 21.

  6-7 illustrate yet another embodiment of the present invention. In the present embodiment, in addition to the cleaning liquid ejecting apparatus having the cleaning liquid ejecting pipe 13 shown in the first embodiment, a brush cleaning means is further provided.

  A cleaning brush 28 is provided at a position facing the lower surface of the air guide casing 10 in the upper cooling air circulation device 12 in the cooling chamber 4. The cleaning brush 28 is a linear brush that extends horizontally along the conveying line of the conveyor 5, and includes a large number of bristles 28 b around the rotating shaft 28 a. A brush rotation motor 29 is supported by a motor support member 30 outside the measuring section of the cooling chamber 4 of the furnace 1, and the rotation shaft of the brush rotation motor 29 is disposed in the cooling chamber 4 through the furnace 1 in an airtight manner. It is connected to the rotating shaft 28a of the cleaning brush 28. Therefore, when the cleaning brush 28 is rotated by the brush rotation motor 29, the flux and flux decomposition products adhering to the lower surface of the air guide casing 10 are removed.

  Further, the screw shaft 31 is disposed outside the measuring section of the cooling chamber 4 of the furnace 1 and extends horizontally in a direction perpendicular to the conveying line of the conveyor 5. The screw shaft 31 is rotatably supported by a support means (not shown) and can be rotated by a motor (not shown). The motor support member 30 has a screw hole engaged with the screw shaft 31, and the screw hole is inserted into the screw shaft 31, and is configured to move on the screw shaft 31 by the rotation of the screw shaft 31. . That is, the cleaning brush 28 is configured to repeat reciprocation from the front to the back and from the back to the front in a direction perpendicular to the conveying line of the conveyor 5 by the motor and control means (not shown). . Accordingly, the cleaning brush 28 moves while cleaning the lower surface of the air guide casing 10 as the screw shaft 31 rotates while being rotated by the brush rotation motor 29. When cleaning is completed, the cleaning brush 28 is configured to be disposed at the end of the cooling chamber 4.

  Since the configuration other than the above configuration is the same as that of the first embodiment described above, the cleaning operation will be described below.

  As described in the first embodiment, the cleaning liquid is sprayed from the cleaning liquid spray tube 13 to wash off the flux and flux decomposition products in the furnace 1. In the present embodiment, at the time of cleaning, the cleaning liquid is ejected from the cleaning liquid spray tube 13 and the cleaning brush 28 repeats reciprocating motion from the front to the back and from the back to the front while rotating the lower surface of the air guide casing 10. Flux and flux decomposition products adhering to the lower surface of the air guide casing 10 facing the conveyor 5 are washed away.

  In addition, although the said embodiment showed what used nitrogen gas as atmosphere gas in the furnace 1, atmosphere gas is not restricted to nitrogen gas. For example, air may be used. When air is used, the gas supplied from the supply pipe 26 may be air. Further, in the present embodiment, the cleaning liquid after cleaning is configured to be recovered from the discharge port to the cleaning liquid tank. However, the present invention is not limited to this. For example, you may collect | recover in a drainage tank. Further, the discharge port for the cleaning liquid may also be used as the discharge port for the liquefied flux. Moreover, in this embodiment, although the example which comprised the furnace from three preheating chambers, one reflow chamber, and one cooling chamber was shown, it cannot be overemphasized that the structure of a furnace is not restricted to this. Absent.

It is a front view showing one embodiment of the present invention. It is the longitudinal cross-sectional view of FIG. 1 cut at right angles to the conveyance line of a conveyor. It is a bottom view of a wind guide casing. It is a front view which shows another embodiment of this invention. FIG. 5 is a longitudinal sectional view of FIG. 4 taken at a right angle to the conveyor conveying line. It is a longitudinal cross-sectional view of the cooling chamber part (conveyor abbreviation | omission) cut along the conveyance line of a conveyor which shows another embodiment of this invention. It is the longitudinal cross-sectional view of FIG. 6 cut at right angles to the conveyance line of a conveyor.

Explanation of symbols

  1 .... Furnace, 2 .... Preheating room, 3 .... Reflow room, 4 .... Cooling room, 5 .... Conveyor, 6 .... Printed circuit board with electronic parts, 7 .... Hot air circulation device, 8 .... Blower , 9 .. Motor 10.. Air guide casing 11. Gas outlet 12. Cooling air circulation device 13 Cleaning liquid injection pipe 14, 16, 18, 22, 25, 27, connection pipe , 15, 19 ··· Distribution pipe, 17 · · Switching valve, 20 · · Supply pump, 21 · · Cleaning liquid tank, 23 · · Discharge port, 24 · · Discharge pipe, 26 · · Supply pipe, 28 · · Cleaning Brush, 28a .. Rotating shaft, 28b .. Hair, 29 .. Brush rotating motor, 30 .. Motor support member, 31.

Claims (13)

  In a cleaning method of a reflow soldering apparatus that heats and solders a substrate on which an electronic component is mounted while being transported by a transport means, the cleaning liquid is sprayed and removed on the flux and flux decomposition products adhered to the furnace. Cleaning method for reflow soldering equipment.   In a cleaning method for a reflow soldering apparatus that heats and solders a substrate carrying electronic components while being conveyed by a conveying means, the flux or flux decomposed product is sprayed onto the flux or flux decomposed material adhering to the furnace. A cleaning method for a reflow soldering apparatus, wherein a surface to be adhered is cleaned with a cleaning member.   In a reflow soldering device that heats and solders a board carrying electronic components while being transported by a transport means, a discharge port is provided for discharging the cleaning liquid after washing off the flux and flux decomposition products adhering to the furnace. A reflow soldering apparatus comprising:   4. The reflow soldering apparatus according to claim 3, wherein the discharge port is also a discharge port for liquefied flux.   A reflow soldering apparatus that heats and solders a board on which electronic components are mounted while being transported by a transport means, and includes a cleaning apparatus for cleaning off flux and flux decomposition products adhering to the furnace using a cleaning liquid. Reflow soldering device.   In a reflow soldering apparatus that heats and solders a board on which electronic components are mounted while being conveyed by a conveying means, the apparatus is equipped with a cleaning apparatus that sprays and removes flux and flux decomposition products adhering to the furnace. Reflow soldering equipment.   In a reflow soldering apparatus that heats and solders a substrate on which an electronic component is mounted while being conveyed by a conveying means, a cleaning liquid tank in which the cleaning liquid is stored, and a cleaning liquid injection device that can inject the cleaning liquid in the cleaning liquid tank into the furnace. A reflow soldering apparatus comprising:   8. The reflow soldering apparatus according to claim 5, wherein the furnace is provided with a discharge port.   9. The reflow soldering apparatus according to claim 7 or 8, wherein the cleaning liquid after cleaning is collected in a cleaning liquid tank.   10. The reflow soldering apparatus according to claim 7, 8 or 9, wherein the cleaning liquid injection device includes a liquid supply pump and a cleaning liquid injection pipe connected to the liquid supply pump and disposed in the furnace. A reflow soldering apparatus, wherein a cleaning liquid in a tank is fed into a cleaning liquid injection pipe, and the cleaning liquid is injected from an injection hole formed in the cleaning liquid injection pipe.   The reflow soldering apparatus according to any one of claims 5 to 10, further comprising a cleaning unit in which a cleaning member is disposed in the furnace, wherein the cleaning member moves along an adhesion surface of flux and flux decomposition products in the furnace. The reflow soldering apparatus is characterized by removing flux and flux decomposition products.   The reflow soldering apparatus according to any one of claims 5 to 10, further comprising a cleaning means in which a cleaning member is disposed in a furnace, wherein the cleaning member rotates along an adhesion surface of flux and flux decomposition products in the furnace. The reflow soldering apparatus is characterized by moving while removing flux and flux decomposition products.   The reflow soldering apparatus according to claim 11 or 12, wherein an outer surface portion of the cleaning member is formed of hair, sponge, or cloth.

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