JPH1168303A - Reflow soldering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make cold air flow right above the upper surface of a printed wiring board and to prevent the elevation of an atmosphere at a high temperature from the clearance of the pin of a chain for supporting and carrying a side end part and the elevation of the temperature of an electronic component loaded on a surface not to be soldered on the upper surface side of the printed wiring board. SOLUTION: A suction port body 81 for which a first suction hole 82 and a second suction hole 83 are formed is provided so as to suck the atmosphere at the high temperature inside a furnace body 10 and to cool the electronic component on the upper surface of the printed wiring board 1 on the upper surface of the side end part 1a of the printed wiring board 1 supported by the pin 20 of the chain 12. A blower 87 for sucking the atmosphere through hoses 85 and 86 connected to the suction port body 81 and discharging it to the outside of the furnace body 10 is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflow soldering apparatus for a plate-shaped work to be soldered, for example, a printed wiring board on which electronic components are mounted.

[0002]

2. Description of the Related Art As a technique for mounting an electronic component on a printed wiring board and performing soldering, there is a reflow soldering technique. This is because solder such as paste solder is supplied in advance to the soldered portion of the printed wiring board on which the electronic component is mounted, then the electronic component is mounted, and then the printed wiring board is reflow soldered This is a technique of heating in a heating furnace of an apparatus to melt the solder in a soldered portion and perform soldering.

In a reflow soldering apparatus, since a printed wiring board is exposed to a high-temperature atmosphere, when soldering an electronic component having a low heat-resistant temperature, the temperature of the component must be prevented from rising above the heat-resistant temperature. There is a need. For example, there is a case where chip-type electronic components compatible with reflow soldering and lead-type electronic components (eg, electrolytic capacitors and the like) not compatible with reflow soldering are mounted together.

[0004] Japanese Patent No. 2502826 (hereinafter referred to as Known Example 1) and Japanese Patent No. 2502827 (hereinafter referred to as Known Example 2) disclose that the temperature of an electronic component having a low heat-resistant temperature does not rise above its heat-resistant temperature. A technique for performing reflow soldering is described. These technologies are
Paste solder is supplied in advance not only to the parts to be soldered of the chip-type electronic components but also to the parts to be soldered of the lead-type electronic components, and the reflow soldering of these parts to be soldered is performed by a reflow soldering apparatus. This is a technology that is performed collectively.

[0005] In these techniques, a printed wiring board on which chip-type electronic components and lead-type electronic components are mixed is printed in the same position as when performing flow soldering, that is, with the lead-type electronic components inserted. This is an excellent technique that allows reflow soldering to be performed above the wiring board.

For this reason, the upper surface side of the printed wiring board on which the lead-type electronic components are mounted is maintained at an ambient temperature equal to or lower than the heat-resistant temperature, the chip-type electronic components are mounted, and the lead wires of the lead-type electronic components are inserted. The reflow soldering is performed after preheating the lower surface side of the printed wiring board where the protruding side of the printed wiring board exists. Of course, the ambient temperature on the lower surface side of the printed wiring board is higher than the ambient temperature on the upper surface side.

In order to maintain the upper surface side of the printed wiring board at an ambient temperature lower than the heat-resistant temperature of electronic components (lead-type electronic components), an external air inlet and an external air inlet fan are provided above the furnace body. Is configured to be sent. Further, it is configured to suppress the rise of a high-temperature atmosphere from below by sending in outside air.

As described above, in the reflow soldering apparatus, an atmosphere having a high temperature tends to move upward. Therefore, there was much difficulty in maintaining the upper side of the printed wiring board at a lower temperature than the lower side,
This has been solved by the techniques of the prior arts 1 and 2 described above.

The inventor of the present invention has developed a technique which is a further advance of the techniques of the prior arts 1 and 2 described in Japanese Patent Application No. 9-76.
No. 49 is being developed. This technology is characterized by the fact that the temperature rise can be suppressed to every corner of the side edge of the printed wiring board, and as a result, the printed wiring board with a high mounting density can be highly mounted over the entire area of the printed wiring board. Even so, desired reflow soldering can be performed while maintaining the electronic component having a low heat-resistant temperature at or below the heat-resistant temperature.

FIGS. 5 and 6 are excerpts of essential parts of Japanese Patent Application No. 9-7649 according to the present invention. FIG. 5 is a sectional side view showing a reflow soldering apparatus, and FIG. FIG. 4 is a cross-sectional view of the reflow section of FIG.

This technique includes a blowing means for blowing an atmosphere outside the furnace body 10, that is, a cool air, and a suction of a high temperature atmosphere inside the furnace body 10 upward from both side ends 1 a of the printed wiring board 1 to the outside of the furnace body 10. It is characterized in that the exhaust means for discharging is provided independently, and the amount of air blown and the amount of exhaust air can be adjusted independently.

In these figures, 1 is a printed wiring board, 2 is an electronic component, 2A is a chip type electronic component, and 2B is a lead type electronic component. In the furnace body 10 of the reflow soldering apparatus, a transfer comprising a chain 12 which is a two-row rotating traveling body that carries and transports while supporting and supporting both side ends 1a of the printed wiring board 1 as a transport means. Conveyor 11
A heating means 1 is provided below the conveyor 11.
3, 14, and 15 are provided. And the conveyor 1
A blower 2 comprising a fan 22 and a motor 23 for blowing outside air outside the furnace body 10 onto the printed circuit board 1 is provided above the furnace 1.
1, a suction and exhaust port 16, a suction and exhaust path 17, and a fan 25 for sucking and exhausting the atmosphere in the furnace body 10 from both sides 1a of the printed wiring board 1. An exhaust unit constituted by a blower 24 including a motor 26 is provided. Reference numeral 27 denotes a carry-in port of the printed wiring board 1 and 28 denotes a carry-out port.

Further, in this reflow soldering apparatus, the preheating section 31 is constituted by one chamber of the heating section 32 and one chamber of the temperature equalizing section 33, and subsequently, one chamber of the reflow section 34 is provided. ing. The heating means 13 of the temperature raising section 32 is configured to use both infrared heating and hot air heating, the heating means 14 of the temperature equalizing section 33 is infrared heating by a panel heater, and the heating means 15 of the reflow section 34 is hot air heating. Configuration.

The sensor 42 provided on the surface of the infrared heater 41 of the temperature raising section 32 detects the surface temperature of the infrared heater 41. The sensor 44 provided on the surface of the panel heater 43 of the temperature equalizing section 33 is also a panel heater. 43 for detecting the surface temperature. That is, a temperature controller (not shown) refers to the temperature detection results of these sensors 42 and 44 and adjusts the power supplied to each heater 41 and 43 so as to reach a predetermined temperature.

The hot air outlet 45 of the reflow section 34
Is provided for detecting the temperature of hot air,
A temperature controller (not shown) adjusts the power supplied to the heater 48 provided in the heating chamber 47 so as to reach a predetermined temperature by referring to the temperature detection result of the sensor 46.

In FIG. 6, a printed wiring board 1 is placed on pins 20 which are support portions of a chain 12 of a transport conveyor 11, supported and transported. At this time, the printed wiring board 1 conveys the portion to be soldered downward.

A chip-type electronic component 2A is mounted on the lower surface 1b of the printed wiring board 1, and a solder paste 9 is applied to a portion to be soldered. The lead type electronic component 2B is mounted on the upper surface side 1c of the printed wiring board 1, and the lead wire 2Ba is inserted through the printed wiring board 1, and the lower surface side 1b of the printed wiring board 1 is soldered. A solder paste 9 is applied to the part.

The lower surface 1b of the printed wiring board 1 is heated by the infrared heater 41, the panel heater 43 and the heater 48 provided below the conveyor 11.

On the other hand, the furnace 1
A fan 22 and a motor 23 for rotating the fan 22 are provided as blowing means for blowing outside cold air, and the atmosphere of cold air outside the furnace body 10, that is, the outside air is
Is sprayed onto the surface of the upper surface side 1c to cool the lead-type electronic component 2B. The opening 51 is an inlet for the outside air provided in the furnace body 10, and the rectifying plate 52 provided at a portion where the outside air is blown to the printed wiring board 1 is for uniformizing the air blowing by the fan 22.

Further, suction / exhaust ports 16 are provided on both side ends 1a of the printed wiring board 1, that is, on both sides thereof along the conveyor 11, respectively.
7 and a hose 19 are connected to the suction port 18 of the blower 24. The exhaust port 53 of the blower 24 is open to the outside.

The partition plate 5 provided on the conveyor 11
Numeral 4 is a member that comes into sliding contact with the furnace body 10,
Is a member that partitions the atmosphere between the lower side and the upper side.

The motors 23 and 26 for driving the fans 22 and 25 are driven by an inverter (not shown) so that the rotation speed can be adjusted. As a result, it is possible to independently adjust the air blowing amount and the exhaust air amount. Note that these configurations correspond to adjusting means for adjusting the amount of blown air and adjusting means for adjusting the amount of exhaust air.

With this configuration, the lead-type electronic component 2 mounted on the upper surface 1c of the printed wiring board 1 and having a low heat-resistant temperature, for example, the lead-type electronic component 2B, is blown with outside air to remove heat. The outside air whose temperature has risen by suppressing the temperature rise of the component 2B and depriving the calorie of the lead-type electronic component 2B is positively sucked from the suction / exhaust ports 16 provided on the both sides 1a of the printed wiring board 1. Can be discharged.

Further, by blowing cool air onto the surface of the upper surface 1c of the printed wiring board 1, it is possible to suppress the high temperature atmosphere that is going to rise from below the conveyor 11 and to increase the temperature of the printed wiring board 1. The high-temperature atmosphere that is about to rise from both sides 1a of the printed wiring board 1 is sucked and discharged from both sides 1a of the printed wiring board 1 in the lateral direction outside thereof. Therefore, the electronic components 2 mounted on both side edges 1a of the upper surface side 1c of the printed wiring board 1
Is not heated by the high temperature atmosphere rising from below.

As described above, the outside air is blown onto the upper surface side 1c of the printed wiring board 1, and the temperature inside the furnace 10 and the atmosphere inside the high-temperature furnace body 10 rising above the conveyor 11 are positively increased. By discharging the heat to the outside of the furnace body 10 to discharge heat, the upper surface 1 of the printed wiring board 1 is
The electronic component 2 mounted on the electronic component 2 can be cooled and its temperature can be kept below the allowable temperature limit.

The atmosphere sprayed on the upper surface 1c of the printed wiring board 1 is applied to both side edges 1a of the printed wiring board 1.
When the electronic components 2 having a low heat-resistant temperature are mounted on both sides 1 a of the printed wiring board 1 by actively sucking and discharging the printed wiring board 1, the high temperature that tends to rise from the lower side of the conveyor 11. I don't touch the atmosphere.

In FIG. 5, the infrared heater 41 of the temperature raising section 32 has a configuration in which a nozzle section 55 is formed to blow hot air between the infrared heaters 41, and a horn section 56 is provided at the tip of the nozzle section 55. It is considered that the hot air supplied and supplied by the blower 57 including the fan 58 and the motor 59 diffuses and blows out over a wide range.
Reference numeral 60 denotes a hot air circulation path, and reference numeral 61 denotes a hot air flow straightening plate.

The heating means 15 of the reflow section 34 is of a hot air circulation type. That is, the heater 48 of the heating chamber 47
In this configuration, the hot air heated in the step (1) is arranged so as to form a uniform flow by the rectifying plate 62 and is blown to the lower surface side 1b of the printed wiring board 1, thereby heating the printed wiring board 1 and its soldered portion. Then, the hot air blown to the printed wiring board 1 returns to the blower 64 including the fan 65 and the motor 66 through the circulation path 63 and the suction port 67, and is heated again in the heating chamber 47 to be printed again. Sprayed on one.
Further, the pressure equalizing plate 68 is a means for uniformly distributing the dynamic pressure of the hot air supplied by the blower 64 over the entire area of the outlet 45, and is used for uniformly blowing out the hot air from the outlet 45 together with the rectifying plate 62. Means.

[0029]

In order to cool the electronic component 2 mounted on the upper surface 1c of the printed wiring board 1 more efficiently, an atmosphere flowing on the upper surface 1c of the printed wiring board 1, that is, a cooling atmosphere is required. It is necessary to flow the outside air / cold air just above the upper surface side 1c of the printed wiring board 1.

A circulating chain 1 is used as a traveling body for supporting and transporting the side end 1a of the printed wiring board 1.
2 is used in the reflow soldering apparatus, and a conveyor 11 for supporting the side end 1a of the printed wiring board 1 on the pins 20 of the chain 12 is used in the reflow soldering apparatus. An atmosphere having a high temperature rises from a gap between the pins 20 and flows into the upper surface 1c of the printed wiring board 1, whereby the temperature of the electronic component 2 mounted on the upper surface 1c of the printed wiring board 1 is increased. There was a problem of raising.

An object of the present invention is to provide a printed wiring board by flowing cold air just above the upper surface of the printed wiring board and discharging the same, and discharging a high temperature atmosphere rising from the side end of the printed wiring board. The temperature on the upper surface side of the board is more stably maintained at a lower temperature, thereby protecting the electronic components having a lower heat-resistant temperature mounted on the upper surface side, and the electrical reliability of the reflow soldered printed wiring board. Is to improve significantly.

[0032]

SUMMARY OF THE INVENTION The present invention relates to a suction device for sucking a high-temperature atmosphere on the upper surface by flowing cold air just above the surface to be cooled of the plate-like work to be soldered, that is, just above the upper surface. A suction hole, which sucks the high temperature atmosphere flowing out from the gap between the support part at the side end of the plate-like work to be soldered and the upper end of the plate-like work to be soldered, to the gap side of the support part. The present invention is characterized in that the formed suction port body is provided, and a heat discharging means for discharging the atmosphere sucked into the suction port body is provided.

[0033] With this arrangement, the cool air having a high wind speed flows just above the upper surface side of the plate-like work to be cooled to be cooled. Can be cooled. In addition, since the high temperature atmosphere rising from the gap between the side end of the plate-like work to be soldered and the transfer means is exhausted, this atmosphere prevents the electronic components having a low heat resistant temperature from being heated. I do.

[0034]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention can be implemented in the following modes.

(1) The reflow soldering apparatus of the present invention is provided with a transport conveyor for transporting a printed wiring board in which solder is previously supplied to a portion to be soldered into a furnace. The printed wiring board is transported with its soldered portion directed downward. Further, a heater for heating the surface of the printed wiring board on the part to be soldered is provided below the conveyor, and a blower for blowing cool air to the upper surface of the printed wiring board is provided.

In the reflow soldering apparatus having such a configuration, the conveyor is constituted by a chain, a chain guide, and a conveyor frame which support and convey both ends of the printed wiring board with pins. A suction port body is formed at the side end of the printed wiring board, the suction port being configured to suction the atmosphere in the furnace along the pins of the chain on the upper surface side of the printed wiring board on which the cool air is blown, and the suction port body is provided. And a blower for sucking and discharging the atmosphere in the furnace body.

(2) In the reflow soldering apparatus of the above (1), a conveyor frame is provided on a chain guide that supports a chain of the conveyor, and the conveyor frame is formed of a hollow member to form a hollow frame. A suction hole for sucking the atmosphere in the furnace is provided in the frame on the pin side of the chain, and a blower for sucking and discharging the atmosphere in the furnace is provided in the hollow frame.

[0038]

【Example】

[First Embodiment] Next, an embodiment of a reflow soldering apparatus according to the present invention will be specifically described.

FIG. 1 shows a first embodiment of the present invention, and is a side sectional view showing the entire reflow soldering apparatus.
5 denote the same parts.

This reflow soldering apparatus is disclosed in Japanese Patent Application No.
No. 7649 to the reflow soldering machine
1 and a blower 87 are provided in series. In this example, the suction port body 81 is connected to the reflow section 34 having the highest heating temperature.
, But may also be provided in the temperature raising section 32 and the temperature equalizing section 33 of the preliminary heating section 31.

FIG. 2 is a cross-sectional view of the reflow section 34 of the reflow soldering apparatus shown in FIG. 1, and the same reference numerals as those in FIG. 6 indicate the same parts. FIG. 3 is a perspective view (as viewed from obliquely below) of the entire suction port body 81 of FIG.

In FIGS. 1 to 3, the suction port body 81 is provided on both sides 1 a of the upper surface side 1 c of the printed wiring board 1, and along the respective chains 12 of the conveyor 11, and supports the chains 12. Are provided on each of the chain guides 71 and the respective conveyor frames 72 that support these chain guides 71. These suction body 8
1 has a first suction hole 82 and a second suction hole 83 formed therein. The first suction hole 82 has a large number of circles, and is located near the side surface 81a of the suction port body 81 shown in FIG.
Are formed in the longitudinal direction. Also, the second suction hole 83
Is formed on the lower surface 81b side of the suction port body 81 on the side having a gap between the pin 20 and the guide plate 73 of the chain 12 for mounting and supporting the side end 1a of the printed wiring board 1.

Each suction port 81 is provided with an exhaust pipe 84 for connecting a hose 85, respectively.
The suction port body 81 is connected to a blower 87 by hoses 85 and 86, respectively. The blower 87 includes a fan 88 and a motor 89, and the first and second blower
This is a heat discharging means for sucking and discharging the atmosphere at an elevated temperature from the suction holes 82 and 83. It is preferable that the blower 87 be configured so that the rotation speed can be adjusted by an inverter or the like so that the exhaust flow rate can be adjusted.

Thus, the outside air, that is, the cool air, blown from above the printed wiring board 1 from the fan 22 provided in the opening 51 of the furnace body 10 flows along the surface of the upper surface side 1c of the printed wiring board 1. At this time, heat is taken from the surface of the lead-type electronic component 2 having a low heat-resistant temperature, is sucked into the first suction hole 82 of the suction port body 81, and is discharged out of the furnace body 10 by the blower 87.

In a high-temperature atmosphere blown from the lower surface side 1b of the printed wiring board 1, reflow soldering is performed by melting the solder in the soldered portion. At this time, the support portion of the chain 12, that is, the printed wiring board 1
The high-temperature atmosphere flowing out from the gap between the pins 20 for mounting and supporting the printed circuit board and the upper surface side 1c of the printed wiring board 1 through the gap between the guide plate 73 is sucked into the second suction hole 83 of the suction port body 81. Is discharged out of the furnace body 10 by the blower 87.

A suction / exhaust passage 17 and an exhaust blower 24 connected to the suction / exhaust passage 17 are provided on both sides 1 a of the printed wiring 1. The blower 24 allows the blower 21 to pass through the opening 51 of the furnace body 10. Of the outside air supplied by the furnace, i.e., the cold air, the excess atmosphere in the furnace body 10 is discharged.
0, the conveyer 11, the suction port body 81 and the like are cooled and discharged.

In this case, a large part of the flow rate of the cool air supplied from the opening 51 is sucked and discharged from the suction port body 81 through the first suction hole 82, and the remainder is drawn from the suction and exhaust port 16 to the suction and exhaust passage 17. It is good to adjust so that it is sucked and discharged.

That is, the cool air that could not be discharged by the suction opening 81 is discharged from the suction / exhaust passage 17, so that the electronic components 2 having a lower heat-resistant temperature above the printed wiring board 1 can be efficiently cooled by the cool air. Good and stable cooling.
Further, there is no influence from the high temperature atmosphere below the printed wiring board 1.

Therefore, it is possible to perform reflow soldering without applying a thermal stress to the electronic component 2 having a low heat-resistant temperature, thereby significantly improving the electrical reliability of the printed wiring board 1.

[Second Embodiment] FIG. 4 is a cross-sectional view showing a second embodiment of the present invention, and is a cross-sectional view corresponding to FIG.

That is, in this example, a conveyor frame made of a hollow member is used as a hollow frame 91 of the conveyor 11 to support a chain guide 71 which is a support for the chain 12, and a suction hole 92 is formed in the hollow frame 91 to form a suction hole 92 of the chain 12. The hollow frame 91 is provided on the side of the pin 20 and the guide plate 73 and the blower 87 is
This is an example in which exhaust is configured to be connected to a vehicle. And
The operation is the same as that of the first embodiment. Further, since the cool air is passed through the hollow frame 91, the hollow frame 91 itself is cooled, the temperature difference in the hollow frame 91 is reduced, and the entire hollow frame 91 is kept constant. Temperature can be maintained. For this reason, even if the hollow frame 91 is disposed over an environment having a temperature difference, the stress is not reduced by heat, and the warpage due to the temperature difference can be prevented.

Although not shown, the hollow frame 91 shown in FIG. 4 is not used, but when the chain guide is also used as a hollow frame, a suction hole is provided in the chain guide, and The chain guide may be connected to the blower 87 by hoses 85 and 86 shown in FIG. 4 so as to exhaust and exhaust heat.

[0053]

As described above, according to the first aspect of the present invention,
According to the invention described above, the cool air is flowed and discharged just above the upper surface of the printed wiring board, and the high temperature atmosphere rising from the side end of the printed wiring board is discharged, so that the upper surface of the printed wiring board is discharged. The electronic components having a low heat-resistant temperature mounted on the printed wiring board can be protected from a rise in temperature, and the electrical reliability of the printed wiring board reflow-soldered can be remarkably improved.

Further, according to the second aspect of the invention, the same effects as those of the first aspect can be obtained even with a simple structure. Further, since cool air is passed through the hollow frame, the temperature difference between the hollow frame itself is reduced, and the entire hollow frame can be maintained at a constant temperature. Therefore, stress caused by the hollow frame being disposed over an environment having a temperature difference is eliminated, and warpage of the chain guide supporting the transport conveyor can be suppressed.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing one embodiment of the present invention.

FIG. 2 is a cross-sectional view of the reflow unit of FIG.

FIG. 3 is a perspective view showing the entire structure of the suction port body of FIG. 2;

FIG. 4 is a cross-sectional view showing a second embodiment of the present invention.

FIG. 5 is a side sectional view showing a conventional example of a reflow soldering apparatus.

FIG. 6 is a cross-sectional view of the reflow unit of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Printed wiring board 1a side edge 1b Lower surface side 1c Upper surface side 2 Electronic component 2A Chip type electronic component 2B Lead type electronic component 2Ba Lead wire 9 Solder paste 10 Furnace body 11 Transport conveyor 12 Chain 13-15 Heating means 16 Suction / exhaust port 17 Suction / Exhaust Channel 20 Pins 21, 24, 57, 64, 87 Blower 31 Preheating Section 32 Heating Section 33 Equalizing Section 34 Reflow Section 51 Opening 53 Exhaust Port 71 Chain Guide 72 Conveyor Frame 81 Suction Port 82 First Suction hole 83 second suction hole 84 exhaust pipe 85, 96 hose 91 hollow frame 92 suction hole

Claims (2)

[Claims] 1. A conveying means for conveying a plate-like work to be soldered in which solder is previously supplied to a part to be soldered into a furnace, a heating means for heating a surface on the side of the part to be soldered, Means for blowing cold air to the other surface of the plate-like work to be soldered, which is different from the surface to be soldered, which is heated by means, and from above both side ends of the plate-like work to be soldered. Exhaust means for sucking the atmosphere inside the furnace and exhausting the atmosphere outside the furnace, wherein the reflow soldering apparatus melts the solder of the soldered portion and performs soldering. A support for supporting both end portions of the soldering work, a traveling body for transporting the plate-like work to be soldered supported by the support, and a support for supporting the traveling body; On the body, A suction port body is formed on the side end side of the work to be soldered, which has a suction hole for sucking the atmosphere in the furnace along the support portion on the upper surface side on which the cold air is blown to the soldering work, and the suction port body is A reflow soldering apparatus, further comprising a heat discharging means for sucking and discharging the atmosphere in the furnace. 2. A conveying means for conveying a plate-shaped work to be soldered in which solder is previously supplied to a part to be soldered into a furnace, a heating means for heating a surface on the side of the part to be soldered, Means for blowing cold air to the other surface of the plate-like work to be soldered, which is different from the surface to be soldered, which is heated by means, and from above both side ends of the plate-like work to be soldered. Exhaust means for sucking the atmosphere inside the furnace and exhausting the atmosphere outside the furnace, wherein the reflow soldering apparatus melts the solder of the soldered portion and performs soldering. A support for supporting both end portions of the soldering work, a traveling body for transporting the plate-like work to be soldered supported by the support, and a support for supporting the traveling body; Supporting means A hollow frame for supporting the inside of the furnace, a suction hole for sucking the atmosphere inside the furnace in the hollow frame is provided on the support portion side, and a heat exhaust means for sucking and discharging the atmosphere inside the furnace is provided in the hollow frame. Characteristic reflow soldering equipment.