JP2004235381A - Solder cooling method, solder cooling device and solder reflow device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a proper solder solidified status by efficiently cooling melting solder after reflow treatment. <P>SOLUTION: A cooling part 140 for cooling the solder of a wiring board treated by a reflow part 120 is provided with cooling devices 140A and 140B in two stages of gentle and quick operations. The first cooling device 140A is configured to gently cool the wiring board 200 by using a cooling fan 142 and an exhaust duct 144 so that at least the surface of melting solder can be solidified. Then, the second cooling device 140B is configured to supply strong cooling air to the solder application face of the wiring board 200 by nozzle spray from an air nozzle 150 so that the inside of semi-melting solder can be quickly cooled. Thus, it is possible to quickly cool the inside of the solder without damaging the surface shape of the solder, to obtain the satisfactory solidified status of the inside of the solder, and to perform the cooling operation in a short time. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a solder cooling method, a solder cooling device, and a solder reflow device for cooling unsolidified solder on a wiring board that has been heated and melted by a reflow process.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as a solder reflow device for a wiring board using lead-free solder mainly from the viewpoint of environmental protection and the like, a device having a preheating unit, a reflow unit, and a cooling unit has been proposed (for example, see Patent Document 1).
That is, in this solder reflow device, the wiring board provided with the unsolidified solder and the electronic components is transported to the preheating unit by the conveyor device, the unsolidified solder is heated by the preheater, and then transported to the reflow unit to cool the electronic components. While reflowing the unsolidified solder is performed.
Then, the unsolidified solder heated and melted by the reflow process is transported to a cooling unit where it is cooled, and the solder is hardened and discharged to a later stage.
In this cooling unit, a gentle cooling air is supplied to the heated and melted solder by a duct and a cooling fan arranged so as to face the wiring board on the conveyor device.
[0003]
[Patent Document 1]
JP, 2002-43733, A
[Problems to be solved by the invention]
By the way, in the prior art as described above, since the solder is cooled and hardened by the cooling unit using the cooling fan and the duct, there is a problem that a relatively long cooling time is required and the product throughput is deteriorated.
Regarding the structural change at the time of solder solidification, generally, the higher the cooling rate, the more nuclei are generated and the crystal grains become finer. And, the finer the crystal grain, the higher the strength and hardness according to Hall-Petch's law. Further, the finer the crystal structure, the less the influence of cracks at the grain boundaries and the like, and the higher the bonding reliability.
[0005]
Therefore, as the hardening and cooling treatment after the solder reflow, it is desirable to increase the cooling rate as much as possible and to improve the reliability of the joint. Conversely, if the crystals become coarse when left at high temperatures, the reliability in terms of strength will decrease.
In particular, in the case of a wiring board using the above-described lead-free solder, the temperature of the reflow treatment is higher than in the case of using the leaded solder, so that the cooling time required by the conventional cooling method is longer, and the product throughput is remarkable. Worse.
Furthermore, if the wiring board is ejected from the reflow device without proper cooling and hardening, mechanical stress such as vibration may be applied to the solder in the subsequent transport path, which may cause problems such as solder cracks. is there.
[0006]
Therefore, in order to overcome such problems, it is conceivable to rapidly cool the molten solder after reflow with a more powerful cooling device, but if strong cooling air is supplied to the molten solder, the solder surface will be deformed. Problems arise.
Although it is possible to perform rapid cooling using a more sophisticated cooling device other than the air supply, there is a problem that the equipment becomes large and the cost increases.
[0007]
Accordingly, an object of the present invention is to provide a solder cooling method, a solder cooling device, and a solder reflow device that can efficiently cool molten solder after a reflow process and obtain a proper solidification state of the solder.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the present invention has a solder cooling step of cooling the unsolidified solder on the wiring board that has been heated and melted by the reflow process, and the solder cooling step includes a step of solidifying at least a solder surface of the unsolidified solder. A first cooling step of cooling by gradual cooling air to a temperature to be cooled, and a second cooling step of rapidly cooling the unsolidified solder cooled by the first cooling step by strong cooling air. Features.
[0009]
Further, the present invention has a solder cooling unit that cools unsolidified solder on the wiring board that has been heated and melted by the reflow process, and the solder cooling unit is gently cooled to a temperature at which at least a solder surface of the unsolidified solder solidifies. It is characterized by including a first cooling device for cooling by cooling air, and a second cooling device for rapidly cooling the unsolidified solder cooled by the first cooling device step by strong cooling air.
[0010]
Further, the present invention provides a preheating section for preheating a wiring board on which unsolidified solder is applied and a component is mounted, and a reflow section for performing a reflow heating process on the unsolidified solder of the wiring board preheated by the preheating section. And a solder cooling unit that cools the unsolidified solder on the wiring board that has been heated and melted by the reflow process of the reflow unit, and a conveying unit that sequentially conveys the wiring board to the preheating unit, the reflow unit, and the solder cooling unit. A first cooling device for cooling by a gradual cooling air to a temperature at which at least a solder surface of the unsolidified solder is solidified; and the solder cooling unit after being cooled by the first cooling device. And a second cooling device for rapidly cooling the solidified solder by strong cooling air.
[0011]
In the solder cooling method, the solder cooling device, and the solder reflow device according to the present invention, when cooling the unsolidified solder on the wiring board that has been heated and melted by the reflow process, the solder cooling step is performed at least until a temperature at which the solder surface solidifies. Cooling by gentle cooling air and then rapid cooling by strong cooling air make it possible to cool efficiently after the surface hardening of the solder without impairing the state of molten solder immediately after reflow treatment. Thus, an appropriate solder solidification state can be obtained.
Therefore, highly reliable soldering can be performed electrically and mechanically, the reliability of the product can be improved, and the manufacturing efficiency can be improved by shortening the cooling operation time.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of a solder cooling method, a solder cooling device, and a solder reflow device according to the present invention will be described.
1 and 2 are diagrams schematically showing an example of the entire configuration of a solder reflow apparatus to which the present invention is applied. FIG. 1 is a side view, and FIG. 2 is a plan view (specifically, a plan view in which heaters 101 and 104 are omitted). Figure).
FIG. 3 is a side sectional view somewhat specifically showing the configuration of the solder reflow apparatus shown in FIGS.
The solder reflow apparatus of this example is for reflowing unsolidified solder (cream solder) for mounting lead components. For example, a chip component is mounted in advance, and the reflow process (chip reflow process) is completed. On the other hand, the apparatus is configured as an apparatus for applying solder for mounting lead components, mounting lead components, and performing solder reflow processing (lead reflow processing) again.
In addition, the reflow processing method for the lead component includes a single-sided reflow method in which hot air is supplied to one entire surface of the wiring board and heated, or a hot air is locally supplied to a connection portion between the lead and the solder and locally heated. Although a spot reflow method and the like are known, a single-sided reflow method will be described in this example.
[0013]
As shown in FIGS. 1 to 3, the solder reflow apparatus of the present embodiment includes a preheat unit (preheat zone) 100, a reflow unit (reflow zone) 120, a cooling unit (cooling zone) 140, and a conveyor device 160. Have.
The conveyor device 160 is, for example, a chain conveyor device that holds the wiring substrate 200 that performs the single-sided reflow process in a state where both surfaces are exposed, and conveys the wiring substrate 200 in the direction indicated by the arrow A to preheat the reheating unit 100, the reflow unit 120, It has a function of sequentially inputting to each part 140 and arranging the wiring board 200 at a predetermined processing position in each part. 1 and 3, the upper surface of the wiring board 200 is the component placement surface, and the lower surface is the solder application surface on which reflow processing is performed.
[0014]
The preheating section 100 is for preheating the wiring board 200 and has three preheating sections 100A, 100B and 100C along the transport direction of the wiring board 200. The first preheating unit 100A arranged at the most upstream has heaters 101 and 102 arranged on both sides of the wiring board 200 and a circulation fan 103 arranged on the upper surface (the component arrangement surface side) of the wiring board 200, The wiring board 200 is preheated from both sides.
The second preheating unit 100 </ b> B disposed second has heaters 104 and 105 disposed on both sides of the wiring substrate 200 and a circulation fan 106 disposed on the upper surface of the wiring substrate 200. Preheat from both sides.
The third preheating unit 100 </ b> C disposed thirdly includes a heater 107 disposed on the lower surface (solder coated surface) of the wiring substrate 200 and a circulation fan 108 disposed on the upper surface of the wiring substrate 200. The substrate 200 is preheated from below.
By the preheating unit 100 having such a configuration, the solder-coated surface of the wiring substrate 200 is sent out to the reflow unit 120 in a state where the soldering surface is preheated to, for example, about 160 ° C. to 180 ° C.
[0015]
Next, the reflow unit 120 performs one-side reflow processing on the solder-applied surface of the wiring board 200 conveyed from the preheating unit 100, and includes a heating device 120A that performs reflow heating on the solder-applied surface, and a component arrangement. And a cooling device 120B for cooling the surface side.
As shown in FIG. 3, heating device 120 </ b> A includes a reflow heater section 122 that supplies hot air to the solder application surface of wiring substrate 200, and a sirocco fan 124 that supplies hot air to this reflow heater section 122.
The reflow heater section 122 has an upper heater 122A and a lower heater 122B. The upper heater 122A and the lower heater 122B are formed with a large number of vertical holes through which air supplied from the sirocco fan 124 passes. Then, the air passing through the ventilation holes is heated and supplied to the solder-coated surface of the wiring board 200. In the upper part of the reflow heater section 122, a large number of holes are opened for uniformly dispersing and discharging the hot air sent through the air holes of the heaters 122A and 122B to the solder-coated surface of the wiring board 200. A reflow panel 123 (see FIG. 1) is disposed.
The sirocco fan 124 supplies the warm air collected through the exhaust pipe 126B of the cooling device 120B to the lower part of the reflow heater unit 122.
[0016]
The cooling device 120B includes an intake fan 120F, a deflecting plate 120H, a shielding plate 120S, and the like. The cooling device 120B is provided in the duct 126A via the deflecting plate 120H and the opening 120a of the shielding plate 120S by the intake fan 120F provided on the upper surface of the facility. The cooling air is taken in and supplied to the upper surface of the wiring board 200. The cooling device 120 </ b> B suppresses heating of electronic components arranged on the upper surface of the wiring board 200.
The duct 126A of the cooling device 120B is provided with a collection duct (not shown) for collecting air supplied to the upper surface of the wiring board 200 and discharging the air to the exhaust pipe 126B. The warmed air is collected and supplied to the sirocco fan 124 through the exhaust pipe 126B.
The reflow unit 120 having such a configuration suppresses a temperature rise on the component placement surface side of the wiring board 200, uniformly heats the solder application surface, heats and melts the solder, and joins the leads of each component to the wiring pattern. I do.
[0017]
Next, the cooling section 140, which is a characteristic part of the present embodiment, will be described.
The cooling unit 140 of the present embodiment cools the heated and molten solder that has been subjected to the reflow treatment by the two-stage cooling devices 140A and 140B.
First, the first cooling device 140A is provided near the outlet of the reflow unit 120, and has a cooling fan 142 arranged below the wiring board 200 and an exhaust duct 144 arranged above the wiring board 200. are doing.
The cooling fan 142 supplies gentle cooling air from the fan to the solder-coated surface of the wiring board 200, and cools the reflow-processed molten solder of the wiring board 200 at a predetermined speed.
The exhaust duct 144 assists the cooling operation on the lower surface side of the wiring board 200 by sucking and exhausting the air on the upper surface of the wiring board 200 by the operation of the exhaust fan 145 provided at the upper part.
[0018]
In the first cooling device 140A, the molten solder of the wiring board 200 is cooled by gentle cooling air, and is cooled at least until the solder surface is hardened. In this case, the cooling temperature at the facility outlet varies depending on the components of the solder to be used, and thus is not fixed, but is at least a temperature lower than the solidus temperature at which the solder hardens, and is generally The solder is completely solidified at a temperature lower by about 20 to 30 ° than the solid phase temperature.
By the cooling of the first cooling device 140A, the solder can be cooled and hardened without impairing the surface shape of the molten solder, and the wiring board 200 can be transported to the second cooling device 140B in a stable state.
In this example, the cooling fan 142 is provided only on the lower surface of the wiring board 200. However, the cooling fan 142 may be provided on both upper and lower surfaces of the wiring board 200 to perform cooling.
[0019]
Next, the second cooling device 140B supplies a strong cooling air to the solder-coated surface of the wiring board 200 by nozzle injection.
FIG. 4 is an explanatory diagram showing an outline of the second cooling device 140B in this example.
The second cooling device 140B includes a compressed air supply pipe (hereinafter, referred to as an air nozzle) 150, an air supply hose 152, an air pressure regulator 154, and a compressed air pump (not shown). I have.
The air nozzle 150 is formed in a tubular shape having a circular cross section, and is provided with a plurality of air discharge holes 151 in a row at predetermined intervals along the longitudinal direction. The air nozzles 150 are arranged along the direction of conveyance by the conveyor device 160, and are provided in a state where the air discharge holes 151 face the lower surface of the wiring board. The tip of the air nozzle 150 is closed.
Each of the air discharge holes 151 is formed in a circular hole shape, and is formed in a tapered shape that expands outward so that compressed air can be effectively ejected.
[0020]
The base end of the air nozzle 150 is connected to an air supply hose 152 via a hose adapter 156, and the air supply hose 152 is connected to a compressed air pump via an air pressure regulator 154.
The compressed air from the compressed air pump is supplied from the air supply hose 152 to the air nozzle 150 at a pressure adjusted by the air pressure regulator 154, and is supplied from each air discharge hole 151 to the solder application surface of the wiring board 200. Thus, the unsolidified solder of the wiring board 200 receives the strong cooling air from each air discharge hole 151 and is rapidly cooled.
With such a second cooling device 140B, the temperature of the solder drops to the solid phase temperature in a relatively short time, and the cooling process after reflow can be completed efficiently.
The cooling air used in the second cooling device 140B can be, for example, cooling air normally used in a factory. It should be set appropriately according to the structure of the air discharge hole, the required cooling temperature, and the like.
[0021]
The second cooling device 140B is not limited to the examples shown in FIGS. 1 to 4 and may be appropriately modified.
For example, in the example of FIG. 1, one air nozzle 150 is provided, but a configuration in which a plurality of air nozzles are arranged in parallel may be adopted. Also, instead of arranging the air nozzles along the transport direction of the wiring board, a plurality of air nozzles may be arranged perpendicular to the transport direction.
Further, in the example shown in FIG. 4, the example in which the compressed air discharge holes are arranged in one row is shown, but it may be arranged in, for example, two rows. Alternatively, as shown in FIG. 5, an air nozzle 150A in which a plurality of air discharge holes 151A are arranged in a staggered arrangement (alternately oblique arrangement) may be provided.
Further, the air discharge hole is not limited to the circular air discharge hole, and a slit (elongated hole) air discharge hole may be provided along the longitudinal direction of the air nozzle. For example, as shown in FIG. 6A, an air nozzle 150B having one slit-shaped air discharge hole 151B may be provided, or as shown in FIG. An air nozzle 150C having an air discharge hole 151C may be provided.
The cross section of the air nozzle 150 may be a shape other than a circle, for example, a polygon such as a rhombus.
[0022]
Next, the outline of the component mounting processing of the wiring board in this example will be described.
FIG. 7 is a flowchart showing the outline of the component mounting process of the present example. FIG. 7A shows a chip component mounting process procedure, and FIG. 7B shows a lead component mounting process procedure.
First, in the chip component mounting process shown in FIG. 7A, cream solder is applied to the chip mounting surface of the wiring board by printing (step S1), and then the chip component is mounted on the wiring board by a chip mounter or the like (step S1). S2).
Then, a chip reflow process is performed using a chip reflow device (not shown) (step S3), and thereafter, the process shifts to an inspection / correction process. Thus, the chip mounting process ends.
[0023]
Next, in the mounting process of the lead component shown in FIG. 7B, cream solder is applied in a spot shape to a specific portion of the solder application surface of the wiring board (step S11). In this operation, a multi-nozzle dispenser system (MDS) collectively applies a large number of solders by a large number of solder supply nozzles (a specific example will be described later).
Next, a lead component is mounted on the solder-coated surface of the wiring board by a lead mounter or the like (Step S12), and a case is mounted on the wiring board (Step S13).
Then, a single-sided lead reflow process is performed using the above-described solder reflow apparatus of the present embodiment (step S14), and after the substrate mounting is completed, the substrate is divided (step S15) to complete each wiring substrate.
Note that such a procedure is merely an example, and does not limit the present invention. Needless to say, various methods can be adopted.
[0024]
FIG. 8 is a sectional view showing each step of the mounting process of the lead component.
First, in FIG. 8A, the chip components 201 and 202 are already mounted on the first surface (solder coated surface) 210 of the wiring board 200, and the reflow processing and the inspection / correction processing have been completed.
Then, the cream solder 300 is applied to the first surface 210 of the wiring substrate 200 in a spot shape from the multiple nozzles 301 of the multi-nozzle dispenser. As shown in the drawing, the mounting position of the lead component uses an area that avoids the mounting position of the chip component.
Next, as shown in FIG. 8B, the wiring substrate 200 is turned over, the second surface (lead component mounting surface) 220 faces upward, and as shown in FIG. , 402, 403, and 404 are inserted into through holes provided in the wiring board 200.
[0025]
Thereafter, the wiring board 200 of the present example is put into a solder reflow device, and a single-sided lead reflow process is performed as shown in FIG.
That is, the second surface 220 side of the wiring board 200 is cooled by the above-described cooling device 120B of the reflow unit 120, and the first surface 210 side is heated by the heating device 120A of the reflow unit 120.
In FIG. 8D, in the cooling device 120B, the cooling air is circulated by the intake fan 120F, the deflecting plate 120H, the shielding plate 120S, and the duct 121 as shown by the arrow α. Further, in the heating device 120A, hot air is supplied to the first surface 210 of the wiring board 200 from the discharge holes 123A provided in the reflow panel 123 to perform a read reflow process.
[0026]
FIGS. 9A and 9B are explanatory diagrams showing an example of a measurement result of a temperature change (temperature profile) of a wiring board in the solder reflow device according to the present embodiment, in comparison with a case of a conventional solder reflow device. FIG. 9A shows an example of measurement results of the solder reflow apparatus of the present example, and FIG. 9B shows an example of measurement results of a solder reflow apparatus corresponding to the conventional example according to Patent Document 1 described above.
In each of the drawings, the vertical axis represents temperature, and the horizontal axis represents time, and represents a temperature change from the above-described preheat zone to the cooling zone via the reflow zone.
In each figure, a group of measurement results indicated by an ellipse X is obtained by measuring the temperature of a component arranged on the first surface of the wiring board, and a group of measurement results indicated by an ellipse Y is obtained by measuring the temperature of the wiring board. This is a measurement of the temperature of components arranged on two surfaces.
[0027]
As shown in the figure, in the preheating zone, the component temperatures on both surfaces of the wiring board gradually rise by preheating, and the temperature of the soldering surface of the first surface subjected to the reflow treatment in the third preheating portion becomes higher. Then, in the reflow zone, the temperature of the soldering surface of the first surface to be reflowed rises significantly, and the component temperature of the second surface on the opposite side is controlled to be substantially constant. Then, by moving to the cooling zone, the first soldering surface is cooled.
As can be seen by comparing FIGS. 9 (A) and 9 (B), a book combining cooling devices 140A and 140B in two stages of fan cooling and nozzle cooling, compared to the conventional example of only fan cooling, is shown. With the cooling unit 140 of the example, the temperature of the soldering surface after the reflow is rapidly reduced, and the cooling and hardening of the solder can be performed effectively.
Thereby, a highly reliable soldering state can be obtained, and the working time can be shortened and the efficiency can be improved.
[0028]
In the above example, the present invention is applied to an apparatus that performs a read reflow process. However, the same cooling method can be applied to a device that performs another reflow process.
Further, the present invention is not limited to the above-described device configured as the solder reflow device, but can be configured as a single cooling device.
In the above-described example, an example in which a lead-free solder is used has been described. However, the present invention is not limited thereto, and the components of the solder to be used can be appropriately changed.
Further, the present invention is not limited to the one-sided reflow process, but can be similarly applied to a spot reflow process.
[0029]
【The invention's effect】
As described above, according to the solder cooling method, the solder cooling device, and the solder reflow device of the present invention, when cooling the unsolidified solder on the wiring board that has been heated and melted by the reflow process, at least the solder cooling step is performed. Cooling by gentle cooling air to the temperature at which the solder surface solidifies, and then quenching by strong cooling air, so that the molten solder immediately after reflow processing is not damaged and the surface of the solder is hardened. Thereafter, cooling can be performed efficiently, and a proper solidification state of the solder can be obtained.
Therefore, highly reliable electrical and mechanical soldering can be performed, so that the reliability of the product can be improved, and the product yield can be improved.
In addition, since the cooling operation time after the reflow treatment can be shortened, it is possible to contribute to the improvement of the manufacturing efficiency and to achieve the effect of reducing the product cost.
[Brief description of the drawings]
FIG. 1 is a side view schematically showing an overall configuration example of a solder reflow apparatus to which the present invention is applied.
FIG. 2 is a plan view schematically showing an overall configuration example of the solder reflow device shown in FIG.
FIG. 3 is a side sectional view somewhat specifically showing a configuration of the solder reflow apparatus shown in FIGS. 1 and 2;
FIG. 4 is an explanatory diagram showing an outline of a second cooling device in a cooling unit of the solder reflow device shown in FIGS. 1 and 2;
FIG. 5 is a perspective view showing another example of the air nozzle provided in the second cooling device shown in FIG.
FIG. 6 is a perspective view showing still another example of the air nozzle provided in the second cooling device shown in FIG.
FIG. 7 is a flowchart illustrating a procedure of a mounting process of a chip component and a lead component according to the embodiment of the present invention.
FIG. 8 is a cross-sectional view showing each step of the mounting process of the lead component in the embodiment of the present invention.
9 is an explanatory diagram showing an example of a measurement result of a temperature change of a wiring board in the solder reflow apparatus shown in FIG. 1 in comparison with a conventional example.
[Explanation of symbols]
100 preheating section, 120 reflow section, 140 cooling section, 140A first cooling device, 140B second cooling device, 142 cooling fan, 144 exhaust duct, 150 air Nozzle, 152, air supply hose, 154, air pressure regulator, 160, conveyor device, 200, wiring board.

Claims (21)

Having a solder cooling step of cooling unsolidified solder on the wiring board that has been heated and melted by the reflow process,
The solder cooling step,
A first cooling step of cooling by gradual cooling air to a temperature at which at least a solder surface of the unsolidified solder is solidified;
A second cooling step of quenching the unsolidified solder after being cooled by the first cooling step with strong cooling air.
A method for cooling solder, characterized in that: The method according to claim 1, wherein the solder is a lead-free solder. 2. The solder cooling method according to claim 1, wherein at least one of a chip component and a lead component is mounted on the wiring board. In the first cooling step, the gentle cooling air is supplied to the unsolidified solder by a cooling fan, and in the second cooling step, the strong cooling air is supplied to the unsolidified solder by a nozzle that emits compressed air. The method according to claim 1, wherein the solder is cooled. The said nozzle is provided with the compressed air discharge hole which faces the said solder application surface in one or several compressed air supply pipes arrange | positioned along the solder application surface of the said wiring board. 5. The solder cooling method according to 4. It has a solder cooling unit that cools the unsolidified solder on the wiring board that has been heated and melted by the reflow process,
The solder cooling unit,
A first cooling device for cooling by a gentle cooling air to a temperature at which at least a solder surface of the unsolidified solder is solidified;
A second cooling device that rapidly cools the unsolidified solder after being cooled by the first cooling device process with strong cooling air.
A solder cooling device, characterized in that: The solder cooling device according to claim 6, wherein the solder is a lead-free solder. 7. The solder cooling device according to claim 6, wherein at least one of a chip component and a lead component is mounted on the wiring board. In the first cooling device, the gentle cooling air is supplied to the unsolidified solder by a cooling fan, and in the second cooling device, the strong cooling air is supplied to the unsolidified solder by a nozzle that emits compressed air. 7. The solder cooling device according to claim 6, wherein: The said nozzle is provided with the compressed air discharge hole which faces the said solder application surface in one or several compressed air supply pipes arrange | positioned along the solder application surface of the said wiring board. 9. The solder cooling device according to item 9. The solder cooling device according to claim 9, wherein a longitudinal direction of the compressed air supply pipe is arranged along a transport direction of the wiring board. The solder cooling device according to claim 9, wherein the compressed air discharge hole is formed in one or a plurality of slits. 10. The solder cooling device according to claim 9, wherein the compressed air discharge holes are formed in a plurality of circular shapes. A preheating section for preheating the wiring board on which the unsolidified solder is applied and the component is mounted,
A reflow unit that performs a reflow process on the unsolidified solder of the wiring board preheated by the preheating unit,
A solder cooling unit that cools unsolidified solder on the wiring board that has been heated and melted by the reflow process of the reflow unit,
Having a conveying means for sequentially conveying the wiring board to a preheating unit, a reflow unit, and a solder cooling unit,
The solder cooling unit,
A first cooling device for cooling by a gentle cooling air to a temperature at which at least a solder surface of the unsolidified solder is solidified;
A second cooling device for rapidly cooling the unsolidified solder after being cooled by the first cooling device by strong cooling air,
A solder reflow apparatus characterized in that: The solder reflow apparatus according to claim 14, wherein the solder is a lead-free solder. The solder reflow apparatus according to claim 14, wherein at least one of a chip component and a lead component is mounted on the wiring board. In the first cooling device, the gentle cooling air is supplied to the unsolidified solder by a cooling fan, and in the second cooling device, the strong cooling air is supplied to the unsolidified solder by a nozzle that emits compressed air. The solder reflow apparatus according to claim 14, wherein The said nozzle is provided with the compressed air discharge hole which faces the said solder application surface in one or several compressed air supply pipes arrange | positioned along the solder application surface of the said wiring board. 18. The solder reflow device according to item 17. 18. The solder reflow apparatus according to claim 17, wherein a longitudinal direction of the compressed air supply pipe is arranged along a transport direction of the wiring board. 18. The solder reflow apparatus according to claim 17, wherein the compressed air discharge hole is formed in one or a plurality of slits. 18. The solder reflow apparatus according to claim 17, wherein the compressed air discharge holes are formed in a plurality of circular shapes.

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