JP3818834B2 - Reflow soldering equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a reflow soldering apparatus for reflow soldering a plate-like workpiece to be soldered with solder supplied to a soldered portion in advance, for example, a printed wiring board on which a large number of electronic components are mounted.
[0002]
[Prior art]
When an electronic component is mounted on a printed wiring board and soldered, a reflow soldering apparatus is used. The reflow soldering apparatus is an apparatus for performing soldering by heating and melting solder that has been supplied in advance to a soldered portion of a work to be soldered such as a printed wiring board.
[0003]
As this heating means, a heat ray heating means such as infrared rays, a hot air heating means for blowing a hot atmosphere, and a heating means using them in combination are often used.
[0004]
On the other hand, the mounted state of the printed wiring board includes a printed wiring board having a soldered portion only on one surface and a printed wiring board having a soldered portion on both surfaces. A printed wiring board with soldered parts on both sides has a printed wiring board that is designed to be reflow soldered on both sides, and one side is reflow soldered while the other side is reflow soldered. The surface has a printed wiring board that is designed to be flow soldered.
[0005]
By the way, there is a printed wiring board in which one surface of the printed wiring board is desired to be cooled while reflow soldering is performed. In other words, the reflow soldering side may be heated, but the other side has an electronic component with a low heat resistance temperature, or the other side has already been soldered. Is heated, the solder of the part to be soldered, which has already been soldered, melts, causing trouble in the soldering.
[0006]
As described above, as a technique for performing reflow soldering while heating one surface side of the printed wiring board and cooling the other surface side, the technology disclosed in Japanese Utility Model Publication No. 3-47340, Japanese Patent No. 2625931, patent There are techniques of Japanese Patent No. 2502826, Japanese Patent No. 2502827, and Japanese Patent Laid-Open No. 10-209627. And all these techniques are comprised so that cold air may be supplied to the surface side which needs cooling of a printed wiring board.
[0007]
[Problems to be solved by the invention]
There are a wide variety of printed wiring boards that are subject to reflow soldering. Printed wiring boards that require reflow soldering by heating both sides together, or reflow soldering on one side. Some printed wiring boards require the other side to be cooled while doing so.
[0008]
However, in the conventional reflow soldering apparatus, the heating mode in which reflow soldering is performed efficiently by performing double-sided heating and the cooling in which the other surface side is efficiently cooled while performing reflow soldering by efficiently heating one surface side. The mode could not be switched.
[0009]
That is, in order to efficiently heat the printed wiring board, the distance between the heating means and the printed wiring board should be close. In particular, when hot-air heating is performed, the amount of heat input to the printed wiring board and thus the soldered part is proportional to the wind speed of the hot air. This is because it is necessary to configure so that the printed circuit board is blown away.
[0010]
Further, in order to efficiently cool the printed wiring board, it is necessary to supply a large amount of cold air to the cooling surface side of the printed wiring board to allow ventilation.
[0011]
For example, in the technology disclosed in Japanese Utility Model Publication No. 3-47340, a passage for cold air is secured, but the heating means is disposed at a position far from the printed wiring board. Therefore, it is difficult to increase the heating efficiency. In particular, Japanese Utility Model Publication No. 3-47340 exemplifies an infrared heater as a heating means. However, if a hot air blowing port is provided at the position of the infrared heater, the hot air is diffused and then blown onto the printed wiring board. As a result, the reflow soldering apparatus is extremely inefficient in heating.
[0012]
The object of the present invention is to switch between a heating mode in which reflow soldering is performed efficiently by performing double-sided heating and a cooling mode in which the other surface side is efficiently cooled while performing reflow soldering by efficiently heating one surface side. By realizing a reflow soldering apparatus that can perform reflow soldering, it is possible to perform reflow soldering of all kinds of printed wiring boards.
[0013]
[Means for Solving the Problems]
In the reflow soldering apparatus of the present invention, when performing reflow soldering, the heating means is brought close to the printed wiring board which is a plate-like work to be soldered, and when cooling is performed, the heating means is kept away from the printed wiring board. The cooling air passage is sufficiently secured, and the cooling air passage means is configured to open in conjunction with the cooling air passage.
[0014]
That is, a reflow soldering apparatus that heats a plate-like workpiece to be soldered with solder supplied to a soldered portion in advance by a heating means, and solders the plate-like workpiece to be soldered. Configure as follows.
[0015]
Conveying means for conveying the plate-like soldered work, first heating means for heating one surface of the plate-like soldering work across the conveying means, and the branch-like soldering And a second heating means for heating the other surface of the workpiece.
[0016]
And, at least one of the first heating means and the second heating means is moved forward and backward with respect to the surface of the plate-like workpiece to be soldered, and in the transport direction of the transport means Ventilation means provided with an air outlet and an air outlet for allowing cool air to flow along the surface of the plate-like soldered workpiece facing the heating means that is provided on the side portion and that moves forward and backward is provided.
[0017]
In addition, in conjunction with the advancing and retreating heating means, there is provided an interlocking opening and closing means that closes when the heating means opens and exits from the surface of the plate-like workpiece to be soldered and opens the air outlet and the air exhaust port. Constitute.
[0018]
Thereby, when performing reflow soldering of a printed wiring board, since a heating means can be advanced and approached to the surface which should be heated of a printed wiring board, efficient heating can be performed now.
[0019]
If it is necessary to cool the other surface (cooled surface) when performing reflow soldering on one surface (heated surface) of the printed wiring board, the heating means is withdrawn from the cooled surface. It is possible to secure a sufficient cool air passage through which a large amount of cool air can be passed along the surface to be cooled, and efficient cooling can be performed.
[0020]
In addition, when the heating means advances, the cool air blowing port and the exhaust port are closed in conjunction with each other, and when the heating means exits, the cold air blowing port and the exhaust port are opened in conjunction with each other. In addition, the heating atmosphere is not leaked to the air blowing port or the exhaust port, and efficient heating can be performed in a sealed state.
[0021]
In particular, in the case of reflow soldering in an inert gas atmosphere with a low oxygen concentration by supplying an inert gas such as nitrogen gas into the reflow soldering device, leakage of the atmosphere causes an increase in oxygen concentration. This causes waste of nitrogen gas. Therefore, the interlocking opening / closing means of the present invention is essential.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
The reflow soldering apparatus according to the present invention can be implemented in the following embodiments. The plate-like soldered work is a printed wiring board on which a large number of electronic components are mounted.
(1) Configuration An embodiment of a reflow soldering apparatus according to the present invention will be described with reference to FIGS.
[0023]
FIG. 1 is a diagram showing a heating mode state of an embodiment of the reflow soldering apparatus of the present invention, and FIG. 2 is a diagram showing a cooling mode state. 1 and FIG. 2 are both a longitudinal sectional view of a reflow soldering apparatus, and FIG. 1 (b) is a lateral sectional view of FIG. 1 (a) (II sectional view in FIG. In FIG. 2, II-II cross section) is shown.
[0024]
That is, heating means (heating chambers) 3 are provided on the lower side and the upper side, that is, on one side and the other side of the printed wiring board 1 along the conveyor 2 that conveys the printed wiring board 1 in the direction of arrow A. It is provided. The heating means 3 is a hot air heating means, and is configured to blow and heat the atmosphere heated by the heater 4 to the printed wiring board 1 by a fan 6 driven to rotate by a motor 5.
[0025]
The hot air is configured to flow in a circulating manner, and the hot air blown to the printed wiring board 1 by the fan 6 passes through the reflux path 8 formed by being partitioned by the flow path forming plate 7 and is again supplied to the fan 6. Reflux. The reflux path 8 is formed on both side end portions when viewed from the conveyance direction A of the printed wiring board 1.
[0026]
Further, the heater 4 for heating the atmosphere is provided in the reflux path 8, and the temperature of the hot air blown against the printed wiring board 1 is detected by a temperature sensor (not shown) provided in the hot air blowing port 9. In this configuration, a temperature control device (not shown) controls the power supplied to the heater 4 so that the predetermined temperature (target temperature) is determined.
[0027]
The hot air blown from the fan 6 is aligned in the direction and the direction of the wind speed by the rectifying means 11 such as the rectifying plate 11 provided with a large number of through holes 11a and intersects the transport direction A of the printed wiring board 1. Are blown out from a large number of row-shaped air outlets 9 and are uniformly blown to the printed wiring board 1.
[0028]
In the reflow soldering apparatus according to this embodiment, the internal configuration of the heating chamber 3 is the same on both the upper side and the lower side of the conveyor 2. However, one heating means 3 can be replaced with another heating means such as an infrared heating means.
[0029]
In addition, the reflow soldering apparatus according to the present embodiment is composed of three heating zones (two zones of the temperature raising portion 13 and the temperature equalizing portion 14 as the preheating portion 12 and one zone of the reflow portion 15). In addition, the heating profile of the printed wiring board 1 can be finely controlled as the heating chambers 3 are subdivided.
[0030]
The air duct 16 and the cold air fan 18 and the air exhaust duct 17 and the air exhaust facing the air duct 16 and the cold air fan 18 so as to face the side of the lower side of the conveyor 2, that is, the lower surface of the printed wiring board 1. Ventilation means 20 comprising a fan 19 is provided. In this embodiment, the ventilation means 20 is provided so as to face the lower surface of the printed wiring board 1, but the same ventilation means 20 may be provided so as to face the upper surface of the printed wiring board 1. Also, it may be provided on both the upper and lower sides.
[0031]
The air outlet 21 and the air outlet 22 of the ventilation means 20 are arranged such that the lower heating furnace body 24 of the lower heating chamber 3 moves up and down, that is, advances toward the board surface of the printed wiring board 1, It is a mechanism that opens and closes in conjunction with the furnace wall 26 when it leaves and leaves.
[0032]
The lower heating chamber 3, that is, the lower heating furnace body 24 is configured to be moved in the vertical direction by the actuator 27, that is, to be advanced and retracted with respect to the plate surface of the printed wiring board 1. As the actuator 27, a pneumatic actuator, a hydraulic actuator, an electric actuator, or the like can be used. The upper heating chamber 3, that is, the upper heating furnace body 23, the transfer conveyor 2, and the ventilation means 20 are separately fixed by a frame (not shown).
[0033]
That is, FIG. 1 shows the case where the lower heating furnace body 24 is raised and the air outlet 9 of the heating means 3 is approaching the plate surface of the printed wiring board 1, that is, the heating mode, and the furnace wall 26 is ventilated. The blowing port 21 and the exhaust port 22 of the means 20 can be closed to perform efficient heating.
[0034]
2 shows a case where the lower heating furnace body 24 is lowered and the air outlet 9 of the heating means 3 is away from the plate surface of the printed wiring board 1, that is, a cooling mode, and the lower side of the printed wiring board 1 is shown. And the furnace wall 26 opens the blower port 21 and the exhaust port 22 of the ventilating means 20 to allow the cool air to flow along the lower surface of the printed wiring board 1. The lower surface can be efficiently cooled.
[0035]
In addition, the sliding member 28 provided in the ventilation port 21 and the exhaust port 22 is a member which slides on the furnace wall 26 of the lower side heating furnace body 24, and keeps sealing of the heating chamber 3, such as a heat resistant rubber member Can be used. Further, the contact member 29 provided at the upper end of the furnace wall 26 of the lower heating furnace body 24 is also made of a heat-resistant rubber member or the like, and the lower heating furnace body 24 is advanced upward as shown in FIG. In this case, it is a member that contacts the shielding plate 30 and keeps the heating chamber 3 sealed.
[0036]
As shown in FIGS. 1B and 2B, the shielding plate 30 is a plate-like member provided on both side end portions of the printed wiring board 1, and includes the conveyor 2 and the printed wiring board 1. This is a member provided so that the atmosphere of the upper heating chamber 3 and the atmosphere of the lower heating chamber 3 are not mixed.
[0037]
In addition, when providing the similar ventilation means 20 so that it may face the upper surface of the printed wiring board 1, although not shown in figure, the upper heating furnace body 23 is comprised so that it can move to an up-down direction with an actuator. In other words, the configuration of the lower heating furnace body 24 shown in FIGS. 1 and 2 may be applied to the configuration of the upper heating furnace body 23. And if comprised in that way, it will become possible to switch between heating and cooling with respect to any of the upper surface and the lower surface of the printed wiring board 1.
[0038]
In this embodiment, the fans 18 and 19 for passing cool air are provided in the blower duct 16 and the exhaust duct 17, but the blowers are connected to the ducts 16 and 17 by piping. May be. That is, the cool air supplied from the blower is blown from the blower duct 16 along the plate surface of the printed wiring board 1, and the exhausted air duct 17 circulates the atmosphere that is blown and contacts the lower surface of the printed wiring board 1 to increase the temperature. Alternatively, the air may be sucked into the blower and exhausted, and the cool air may be passed along the lower surface of the printed wiring board 1.
(2) Operation As shown in FIG. 1, if the lower heating furnace body 24 is raised and the heating chamber 3, which is a heating means, and the hot air blowing port 9 are advanced to the lower surface of the printed wiring board 1, The ventilation port 21 and the exhaust port 22 of the ventilation means 20 are closed. Then, the rotation of the cool air blowing fan 18 and the exhaust fan 19 of the ventilation means 20 is also stopped.
[0039]
Therefore, the upper and lower surfaces of the printed wiring board 1 can be heated by hot air. In this case, since the hot air blowing port 9 can be positioned close to the plate surface of the printed wiring board 1, that is, the soldered surface, it can be efficiently heated.
[0040]
Of course, when the printed wiring board 1 to be reflow soldered has a soldered portion only on one surface thereof, for example, the printed wiring board 1 is carried into the reflow soldering apparatus with the soldered surface facing upward, It is also possible to perform reflow soldering only on the upper surface of the plate 1 and to heat the lower surface auxiliary. The reverse is also possible. That is, in the state of FIG. 1, it operates as a normal reflow soldering apparatus.
[0041]
That is, the printed wiring board 1 carried in from the carry-in port 31 of the reflow soldering apparatus is supported by the conveyer 2 and conveyed in the direction of arrow A, and the heating chamber 3 of the temperature raising unit 13 and the heating chamber of the temperature equalizing unit 14. 3 is preheated and the reflow soldering is performed in the heating chamber 3 of the reflow part 15 by melting the solder of the soldered part. Then, it is carried out from the carry-out port 32.
[0042]
On the other hand, as shown in FIG. 2, if the lower heating furnace body 24 is lowered and the heating chamber 3, which is a heating means, and then the hot air blowing port 9 are retreated from the lower surface of the printed wiring board 1, The blower port 21 and the exhaust port 22 of the ventilating means 20 are opened, and a wide passage for allowing cool air to flow between the lower surface of the printed wiring board 1 and the blower port 9 can be formed. And the cool air blowing fan 18 and the exhaust fan 19 of this ventilation means 20 are also rotated.
[0043]
Accordingly, a large amount of cold air can be passed along the lower surface while heating the upper surface of the printed wiring board 1 with hot air, and the lower surface can be efficiently cooled. Will be able to.
[0044]
That is, the printed wiring board 1 carried in from the carry-in entrance 31 of the reflow soldering apparatus is supported by the conveyer 2 and conveyed in the direction of arrow A, and the upper surface thereof is connected to the heating chamber 3 and the leveling unit 13 of the temperature raising unit 13. Preheating can be performed in the heating chamber 3 of the warm section 14 and reflow soldering can be performed in the heating chamber 3 of the reflow section 15. Moreover, the lower surface can be efficiently cooled by cold air.
[0045]
In addition, when the ventilation means 20 for cooling the printed wiring board 1 is provided so as to face the upper surface of the printed wiring board 1 as well, the above efficient heating can be performed on the upper surface as well. And efficient cooling can be selected and performed.
(3) Other Embodiments Next, other embodiments of the reflow soldering apparatus according to the present invention will be described.
[0046]
In the embodiment shown in FIGS. 1 and 2, the three heating means of the preheating unit 12 and the reflow unit 15, that is, the heating unit 13 and the soaking unit 14, that is, the heating chamber 3 are integrated with the lower heating furnace body 24. However, for example, only the heating chamber 3 of the reflow unit 15 having the highest heating temperature may be configured to be movable in the vertical direction. In this case, heating and cooling of the lower surface of the printed wiring board 1 can be switched only in the reflow unit 15.
[0047]
Further, such heating and cooling switching means can be set for each heating chamber 3.
[0048]
2, in each heating chamber 3 of the lower heating furnace body 24, the fan 6 is rotated in the direction opposite to the direction shown in FIG. 1 to reverse the circulation direction of the atmosphere. . This is because the type of the printed wiring board 1 to be reflow soldered changes, and immediately after switching from the heating mode to the cooling mode, the cooling of the lower heating chamber 3 that has become high temperature in the heating mode is accelerated. . In other words, the heating chamber 3 can be rapidly cooled by sucking cold air flowing along the lower surface of the printed wiring board 1 from the air outlet 9. As a result, the lead time of the production switching time can be shortened, and the productivity can be increased.
[0049]
【The invention's effect】
As described above, according to the reflow soldering apparatus of the present invention, the heating mode in which both sides of the printed wiring board are efficiently heated to perform reflow soldering and the reflow soldering by efficiently heating one side are performed. However, it becomes possible to switch between the cooling mode for efficiently cooling the other surface side, and it becomes possible to perform reflow soldering of all printed wiring boards with one reflow soldering apparatus. In addition, both high efficiency heating and high efficiency cooling can be achieved.
[0050]
In addition, immediately after switching to the cooling mode, the heating chamber can be rapidly cooled by reversely rotating the fan of the heating chamber through which the cool air passes. That is, the lead time associated with the production switching to different types of printed wiring boards can be shortened, and the productivity of reflow soldering in multi-product production can be increased.
[Brief description of the drawings]
FIG. 1 is a diagram showing a heating mode state of an embodiment of a reflow soldering apparatus according to the present invention.
FIG. 2 is a diagram showing a state of a cooling mode.
[Explanation of symbols]
1 Printed wiring board 2 Conveyor 3 Heating chamber (heating means)
4 Heater 5 Motor 6 Fan 7 Flow path forming plate 8 Recirculation path 9 Blowing port 11 Rectifier plate 11a Through-hole 12 Preheating part 13 Temperature rising part 14 Temperature equalizing part 15 Reflow part 16 Air duct 17 Exhaust duct 18 Cold air air fan 19 Exhaust fan 20 Ventilation means 21 Blower port 22 Exhaust port 23 Upper heating furnace body 24 Lower heating furnace body 26 Furnace wall 27 Actuator 28 Sliding member 29 Contact member 30 Shield plate 31 Carry-in port 32 Carry-out port

Claims (1)

A reflow soldering apparatus for performing soldering of the plate-shaped workpiece to be soldered by heating with a heating means a plate-shaped workpiece to be soldered in which solder is supplied in advance to the soldered portion,
Conveying means for conveying the plate-like workpiece to be soldered;
A first heating means for heating one surface of the plate-like workpiece to be soldered across the conveying means;
A second heating means for heating the other surface of the plate-like workpiece to be soldered;
Advancing / retreating means for advancing / retreating at least one of the first heating means and the second heating means with respect to the surface of the plate-like workpiece to be soldered;
Ventilation means provided on the side of the conveying direction of the conveying means and provided with an air outlet and an air outlet for allowing cold air to flow along the surface of the plate-like soldered workpiece facing the heating means moving forward and backward When,
In conjunction with the advancing and retreating heating means, the heating means comprises an interlocking opening / closing means that opens when the air outlet and the air exhaust opening are opened and advanced when the heating means retreats from the surface of the plate-like workpiece to be soldered. A reflow soldering device.

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