JPH09214123A - Reflow equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce imperfect soldering caused by delivery difference of heat which turns to temperature irregularity on a printed board. SOLUTION: A coil type heater 8 is arranged in a duct 7, and a straightening region 10 where two slit type nozzles 9 whose directions are different by 90 deg. to the circulation direction of atmosphere are alternately arranged is formed in the outlet of the duct 7. The atmosphere which has passed the straightening region 10 is jetted against a printed board, at a uniform wind velocity of 3-5m/sec. A lower surface heating part having a plate provided with a plurality of hot air jetting ports is installed under a rail 14. Hot air jetted from the lower surface heating part is branched from the middle part of a circulation path of the atmosphere of the heating part and supplied. Heating is performed by arranging a second heater just in front of the plate 17. The hot air capable of imparting temperature gradient is jetted at a velocity of 4-5m/sec.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflow device used for heating and melting a solder paste on a printed board to solder an electronic component to an electric circuit on the printed board.

[0002]

2. Description of the Related Art Recently, as a means for connecting an electronic component to an electric circuit on a printed circuit board, a method of arranging the electronic component on a solder paste printed on the printed circuit board and performing reflow soldering collectively is often used. Has been.

As shown in FIG. 6, the reflow device used in this batch reflow soldering has a carrying section 2 on which the printed board 1 is placed and carried, and a printed board 1 carried by the carrying section 2. First heater 18 for heating and melting the solder paste, fan 21 for stirring, convection, or circulating the atmosphere in the heating section, and second heater for auxiliary heating of the lower surface of printed circuit board 1. The heating unit 16 includes a heating unit 16, a cooling unit 5 for cooling the printed circuit board 1 heated when the solder is melted, and an electric control unit for controlling these.

[0004]

However, in the above-mentioned conventional example, since the temperature and the wind speed over the entire atmosphere when the printed circuit board is heated in the heating section are not sufficiently controlled, the temperature variation on the printed circuit board may be reduced. There is a problem in that a difference in heat transfer occurs, which causes a soldering failure.

In view of the above-mentioned conventional problems, the present invention provides a reflow apparatus for controlling the temperature and the wind speed over the entire heating part atmosphere.

[0006]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention has a carrying section for mounting and carrying a printed circuit board,
A heating unit having a first heating unit for heating and melting the solder paste on the printed circuit board to connect the electronic component to an electric circuit on the printed circuit board, and a cooling unit for cooling the printed circuit board after heating. A cooling unit, a fan for compressing and blowing the atmosphere of the heating unit, and a fan for circulating the inside of the furnace, forming a path through which the atmosphere circulates, and a duct for arranging a first heater as a first heating means; ,
A rectifying area is provided between the duct outlet and the upper side of the printed circuit board transporting section, and as the second heating means, an atmosphere heated from the lower surface of the printed circuit board is blown below the rail for transporting the printed circuit board. A lower surface heating duct for heating the printed circuit board by means of a lower surface heating section, which constitutes a path through which an atmosphere blown out from the lower surface heating section passes, and a second heater as a second heating means is arranged; A plate provided with a plurality of hot air outlets at the exit of the lower surface heating duct located under the transfer section, which is on a plane parallel to the transfer surface of the printed circuit board, parallel to and perpendicular to the direction of travel of the printed circuit board. Is.

According to the present invention, it is possible to obtain a reflow apparatus for controlling the temperature and the wind speed over the entire heating portion atmosphere.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is to carry an electronic component on a printed circuit board by carrying a printed circuit board on which a printed circuit board is placed and carried and a solder paste on the printed circuit board by heating and melting. A heating unit having a first heating unit for connecting to a circuit, a cooling unit having a cooling unit for cooling the printed circuit board after heating, and the atmosphere of the heating unit is compressed and blown to circulate in the furnace. A duct for arranging a path for circulating the atmosphere and for arranging a first heater as a first heating means, and a rectifying region is provided between the duct outlet and the upper side of the printed circuit board transport section. In addition, the circulating atmosphere can be heated uniformly and efficiently, and the air velocity of the atmosphere blown onto the printed circuit board can be kept constant.

According to a second aspect of the present invention, the ducts are arranged on the lower side and the inner side of the substrate transfer section,
While configuring the circulation path of the atmosphere around the transport unit,
The effect that the transfer part can be seen directly when the furnace body composed of the heating part is opened, and the electrical parts placed in or near the duct are located on the back side of the furnace body or below the furnace body. Since the electric control section can be integrated into one unit, the safety can be improved and the electric wiring can be shortened.

According to a third aspect of the present invention, in the heating section, a coil-shaped heater is provided as the heating means, the heater itself can be made small, and work such as attachment and detachment is easy. And the effect that a heater with a relatively large capacity can be used in a small and limited space, and that heat exchange can be performed quickly and efficiently even in a moving atmosphere. Also, the duct in which the heater is arranged and the heating portion in which the duct is inserted can be downsized.

According to a fourth aspect of the present invention, two kinds of slit-shaped nozzles different in 90 ° direction with respect to the circulation direction of the atmosphere are alternately arranged as the rectifying region, and the circulating atmosphere Has the effect of rectifying the air flow and adjusting the wind speed uniformly.

According to a fifth aspect of the present invention, the wind velocity blown onto the upper surface of the printed board from the slit-shaped nozzle is set to a constant wind velocity of 3 to 5 meters per second in the longitudinal direction of the slit opening. It has an effect of effectively and uniformly heating the conveyed printed circuit board, the soldering components and the soldering material on the printed circuit board without damaging them.

According to a sixth aspect of the present invention, the wind velocity blown from the slit nozzle onto the upper surface of the printed circuit board is 1 to 10 per second in the longitudinal direction of the slit opening.
It is possible to adjust the wind speed gradient freely in the range of meters, and it is possible to change the wind speed that is constant in the slit opening longitudinal direction according to the type of printed circuit board and parts. Have.

According to a seventh aspect of the present invention, in the slit-shaped nozzle, a direction perpendicular to a direction in which the atmosphere circulates inside the furnace body and a direction parallel to a wall surface of an outer edge of the atmosphere path. The first nozzle, in which each side of the nozzle inlet side is arranged in parallel, is installed with a gap of about 5 to 50 mm from the wall surface, and the temperature of the outer peripheral portion generated in the circulation path of the heating unit is lowered. It has the effect of removing the atmosphere from the circulation path for heating the printed circuit board.

According to the eighth aspect of the present invention, as a second heating means different from the heating means, an atmosphere heated from the lower surface of the printed circuit board is blown to the lower side of the rail for conveying the printed circuit board. A lower surface heating duct for heating the printed circuit board by means of a lower surface heating section, which constitutes a path through which an atmosphere blown out from the lower surface heating section passes, and a second heater as a second heating means is arranged; A plate provided with a plurality of hot air outlets at the exit of the lower surface heating duct located under the transfer section, which is on a plane parallel to the transfer surface of the printed circuit board, parallel to and perpendicular to the direction of travel of the printed circuit board. Therefore, this occurs when a component having a large heat capacity is mounted on the back surface of the printed circuit board, which is difficult to prevent by the first heating means. Prevents temperature variations on the surface of the printed circuit board and compensates for incomplete uniformity of the temperature on the printed circuit board surface when the first heating means is inefficient, and also makes efficient use of hot air blown from the lower surface of the printed circuit board. It has the effect of heating well and being able to evenly distribute it to each outlet, and also to keep the wind velocity of the hot air constant.

According to a ninth aspect of the present invention, a fan for circulating the atmosphere of the heating portion, a lower surface heating duct that constitutes a path through which the atmosphere circulates, and a heating means in the lower surface heating duct. In the reflow device in which the first heater is arranged, the atmosphere blown out from the lower surface heating unit is branched and supplied from the middle of the circulation path of the atmosphere of the heating unit, and as a moving means of the hot air blown out from the lower surface heating unit. This has the effects of eliminating the need for a dedicated fan and suppressing the electric capacity of the heating means for blowing hot air to a low level.

According to a tenth aspect of the present invention, the second heater is arranged immediately below the plate in a passage path of an atmosphere blown out from a lower surface heating section, and
The second heater is arranged so that the temperature of the atmosphere blown out from the plurality of hot air outlets of the plate rises according to the passage length in the lower surface heating duct. A function of giving a temperature gradient to the hot air that blows out so that the temperature rises according to the passage length, and compensating for the temperature decrease of the outer peripheral part in the circulation path of the heating part which may occur in the first heating means. Have.

According to an eleventh aspect of the present invention, the wind velocity of the hot air blown from the nozzle of the lower surface heating unit is kept constant at 4 to 5 meters per second, and the back surface of the printed circuit board has a large heat capacity. Temperature variations on the printed circuit board surface that occur when, for example,
When the temperature uniformity of the printed circuit board surface is not complete with the first heating means, the function of effectively and uniformly heating and compensating the printed circuit board and the components on the back surface of the printed circuit board without damage Have.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. (Embodiment 1) FIGS. 1 and 2 show a reflow apparatus according to the present invention, in which a carrying section 2 for mounting and carrying a printed circuit board 1 and a plurality of heatings for heating and melting a solder paste on the printed circuit board 1 are provided. It is composed of a heating unit 4 having a chamber 3 and a cooler 5 for cooling the heated printed circuit board 1. In each heating chamber 3 of the heating unit 4, a sirocco fan 6 is installed below the transport unit 2, The atmosphere blown by the sirocco fan 6 is sent from the lower side of the conveying section 2 to the duct 7 arranged on the back side, and the atmosphere is heated by the coiled heater 8 arranged in the duct 7, and the outlet of the duct 7 is discharged. In the printed circuit board 1 at a uniform wind speed of 3 to 5 meters per second, the atmosphere passed through the rectifying region 10 in which two slit-shaped nozzles 9 different from each other in the traveling direction 20 of the atmosphere are alternately arranged. It is blown in.

The duct 7 of the iron is a casing portion which forms a part of a spiral outer shape which covers the periphery of the sirocco fan 6, and a cylindrical portion which circulates the atmosphere from this casing to the slit nozzle 9 above the heating chamber 3. The coiled heater 8 is inserted into and attached to the cylindrical portion from the rear surface of the reflow device.

These duct 7, coiled heater 8,
Further, the rectifying region 10 has an effect that the circulating atmosphere can be heated uniformly and efficiently, and the atmosphere blown to the printed circuit board 1 has a constant wind speed.

Further, by arranging the duct 7 from the lower side to the inner side of the conveying section 2, the effect that the conveying section 2 can be seen directly when the furnace body is opened, and further, the inside of the duct 7 or the duct 7 can be seen. Since the electric parts arranged near the can be collectively put in the electric control section located on the back side of the furnace body or the lower side of the furnace body, it has an effect of improving safety and shortening the electric wiring. There is.

By adopting the coiled heater 8, the heater itself can be made small, and the operation such as mounting and dismounting can be easily performed, and a heater having a relatively large capacity can be used in a small and limited space. The effect that heat can be exchanged quickly and efficiently even in a moving atmosphere, and further, due to the effect, the duct 7 for arranging the heater and the heating section 4 in which the duct 7 is inserted can be downsized. Have an effect.

By heating at a uniform wind speed of 3 to 5 meters per second, the printed circuit board 1 and the soldered parts and soldering material on the printed circuit board 1 can be effectively and without damage. It has the effect of heating uniformly.

In the above description, the rectification area 10 is 9
Although the configuration in which two types of slit-shaped nozzles having different 0 ° directions are alternately arranged has been described, a honeycomb structure or the like in which the opening faces on the inlet side and the outlet side are inclined with each other or the paths are curved is used. Also has the same effect.

Further, a uniform wind speed can be adjusted within a range of 1 to 10 meters per second, and a gradient of the wind speed can be freely adjusted in the longitudinal direction of the opening, so that the printed circuit board 1 and the type of parts can be adjusted. You can change the wind speed,
Furthermore, versatile heating conditions can be realized.

(Second Embodiment) FIGS. 3 and 4 show a rectification area 1
0 is a detailed view of No. 0, the first nozzle 11 is a direction substantially perpendicular to the advancing direction 20 of the atmosphere inside the furnace body, and each side of the nozzle inlet side is parallel to the wall surface at the outer edge of the path of the atmosphere. They are arranged parallel to each other, and the whole of them is attached to be inclined with respect to the wall surface. Further, the first nozzle 11 is 5 from the wall surface.
It is installed with a gap of about 50 mm.

The second nozzle 12 is the printed circuit board transport section 2.
Of the plurality of nozzles arranged side by side, and a space is provided between the nozzles located above the printed circuit board 1 and the nozzles.

Of these nozzles, the first nozzle 11
Changes the advancing direction of the atmosphere, divides the atmosphere evenly in the direction parallel to the conveying direction of the printed circuit board 1, and further reduces the temperature of the outer peripheral part generated in the circulation path of the heating section 4 to the printed circuit board. It has the action of removing 1 from the circulation path for heating.

The second nozzle 12 diverts the atmosphere in a direction perpendicular to the direction in which the printed circuit board 1 is conveyed, and narrows the flow path to make the wind speed uniform. Furthermore, by providing a space between the nozzles, vortices are generated in the space, and the stagnation point on the substrate is reduced, so that heat transfer is improved.

(Embodiment 3) FIG. 5 shows a lower surface heating section 13 as a second heating means, which is for heating the lower surface of the printed circuit board 1 below a rail 14 for conveying the printed circuit board 1. The lower surface heating unit 13 is provided to form a path through which the atmosphere blown out from the lower surface heating unit 13 passes,
The lower surface heating duct 16 in which the second heater 15 as the second heating means is arranged, and the outlet of the lower surface heating duct 16 arranged under the printed circuit board transfer section 2 are arranged on a plane parallel to the transfer surface of the printed circuit board 1. A plate 17 having a plurality of hot air outlets is provided in a direction parallel to the traveling direction of the printed circuit board 1 and in a direction perpendicular thereto.

Further, the atmosphere blown from the lower surface heating unit 13 is branched and supplied from the middle of the circulation path of the atmosphere of the heating unit 4, and the wind speed is kept constant at 4 to 5 meters per second. The second heater 15 is arranged directly below the plate 17 of the outlet in the passage of the atmosphere that blows out more, and the second heater 15
Thus, the atmosphere blown out from the plurality of hot air outlets of the plate 17 is arranged so that the temperature rises according to the passage length in the lower surface heating duct 16.

Thus, it is possible to prevent the temperature variation of the printed circuit board surface which is difficult to prevent by the first heating means and which occurs when a component having a large heat capacity is loaded on the back surface of the printed circuit board and the temperature of the printed circuit board surface. Is used to assist in the case where the first heating means is not uniform, and the hot air blown from the lower surface of the printed circuit board 1 is efficiently heated and evenly distributed to the respective outlets so that the wind speed of the hot air is increased. It has the effect of making it constant.

Further, a dedicated fan as a means for moving the hot air blown from the lower surface heating section 13 is not required, and
The function of keeping the electric capacity of the heating means of the hot air blown out low and the constant velocity of the hot air blown out from the hot air blowout port of the plate 17 are 4 to 5 meters per second, so that the printed circuit board 1 and the prints are printed. It has the effect of heating the components on the back surface of the substrate effectively and uniformly without damaging them.

Further, by the arrangement method of the second heater 15, a temperature gradient is given to the hot air blown out from the lower surface heating section 13 so that the temperature becomes higher according to the passage length, and it is generated by the first heating means. It has an effect of making it possible to compensate for the temperature decrease of the outer peripheral portion in the circulation path of a certain heating unit 4.

Although the wind speed of the hot air is limited to 4 to 5 meters per second, by changing the setting of the upper or lower limit of this wind speed, more versatile heating conditions can be realized.

[0037]

As described above, the reflow device according to the present invention connects the electronic parts to the electric circuit on the printed circuit board by placing and carrying the printed circuit board and the solder paste on the printed circuit board by heating and melting the solder paste. A heating unit having a first heating unit for controlling the temperature of the printed circuit board, a cooling unit having a cooling unit for cooling the printed circuit board after heating, and a fan for circulating the atmosphere of the heating unit in a compressed manner. A duct in which the atmosphere is circulated and in which a first heater as a first heating means is arranged, and a rectification area is provided between the duct outlet and the upper side of the printed circuit board transporting section, The atmosphere to be heated can be uniformly and efficiently heated, and the wind speed of the atmosphere blown onto the printed circuit board can be made constant.

Further, by arranging the ducts on the lower side and the inner side of the substrate transfer section, a path through which the atmosphere circulates is formed around the transfer section, but when the furnace body composed of the heating section is opened. The transport section can be seen directly, and the electrical parts that are placed in or near the duct can be centralized in the electric control section located on the back side of the furnace body or under the furnace body, improving safety. Also, the electric wiring can be shortened.

Furthermore, by providing a coiled heater as the heating means in the heating section, the heater itself can be made small, and work such as mounting and dismounting can be facilitated, and a heater having a relatively large capacity can be installed in a small and limited space. Can be used. Also, heat exchange can be performed quickly and efficiently even in a moving atmosphere. Further, the duct in which the heater is arranged and the heating section in which the duct is inserted can be downsized.

As a rectifying region, 9 in the circulation direction of the atmosphere
By arranging two kinds of slit-shaped nozzles having different 0 ° directions alternately, the circulating atmosphere can be rectified and the wind speed can be made uniform.

The wind speed blown from the slit-shaped nozzle onto the upper surface of the printed circuit board is kept constant at a rate of 3 to 5 meters per second in the longitudinal direction of the opening of the slit, so that the printed circuit board to be conveyed and soldered parts on the printed circuit board and The soldering material can be heated effectively and uniformly without damaging it.

The speed of the wind blown onto the upper surface of the printed board from the slit-shaped nozzle can be adjusted in the range of 1 to 10 meters per second in the longitudinal direction of the slit, and the gradient of the wind speed can be adjusted freely, so that the opening of the slit can be adjusted. The wind speed, which is constant in the longitudinal direction, can be changed according to the types of printed circuit boards and parts.

Of the slit-shaped nozzles, each side on the nozzle inlet side is arranged in a direction perpendicular to the direction in which the atmosphere circulates inside the furnace body and parallel to the wall surface of the outer edge of the atmosphere path. One nozzle is 5 to 50 from the front wall.
By installing with a gap of about mm,
The atmosphere in which the temperature of the outer peripheral portion is lowered, which is generated in the circulation path of the heating unit, can be removed from the circulation path for heating the printed circuit board, and variations in temperature on the printed circuit board can be reduced.

Below the rail for carrying the printed circuit board,
The lower surface of the printed circuit board is provided with a lower surface heating unit for heating the printed circuit board by heating the lower surface of the printed circuit board, and a second heater as a second heating means is configured as a path through which the atmosphere blown out from the lower surface heating unit passes. At the bottom heating duct to be placed and at the bottom heating duct outlet located below the printed circuit board transport section, a plurality of hot air blows on the plane parallel to the PCB transport surface, parallel to and perpendicular to the direction of travel of the PCB. By providing a plate with a mouth, it is difficult to prevent with the first heating means,
Prevents temperature variations on the printed circuit board surface that occur when parts with large heat capacity are loaded on the back side of the printed circuit board, and the temperature uniformity on the printed circuit board surface is not complete with the first heating means. Can compensate for this. In addition, the hot air blown from the lower surface of the printed circuit board can be efficiently heated and evenly distributed to each outlet, and the wind speed of the hot air can be made constant.

By supplying the atmosphere blown out from the lower surface heating section by branching from the middle of the circulation path of the atmosphere in the heating section, a dedicated fan as a moving means for the hot air blown out from the lower surface heating section is not required and the hot air blown out is eliminated. The electric capacity of the heating means can be kept low.

The second heater is arranged immediately below the plate within the passage of the atmosphere blown out from the lower surface heating portion, and the atmosphere blown out from the plurality of hot air blowout ports of the plate by the second heater is in the lower surface heating duct. By arranging so that the temperature rises according to the passage length, the hot air blown out from the lower surface heating section is given a temperature gradient so that the temperature rises according to the passage length, and is generated by the first heating means. It is possible to compensate for the temperature decrease of the outer peripheral portion in the circulation path of the heating portion which may occur.

Since the wind velocity of the hot air blown from the nozzle of the lower surface heating unit is kept constant at 4 to 5 meters per second, the front surface of the printed circuit board which is generated when a component having a large heat capacity is loaded on the back surface of the printed circuit board. If the first heating method is not sufficient for the temperature variation of the PCB and the uniformization of the temperature of the printed circuit board surface, the printed circuit board and the components on the back surface of the printed circuit board can be heated effectively and uniformly without damage. You can make up for it.

According to the present invention described above, a reflow apparatus for controlling the temperature and the wind speed over the entire heating part atmosphere can be obtained.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an internal configuration of a reflow device according to a first embodiment.

FIG. 2 is a front sectional view showing the internal configuration of the reflow device according to the first embodiment.

FIG. 3 is a partial detailed side sectional view of a rectifying region according to the second embodiment.

FIG. 4 is a partial detailed front sectional view of a rectifying area according to a second embodiment.

FIG. 5 is a side sectional view of a lower surface heating unit in the third embodiment.

FIG. 6 is a front sectional view of a conventional reflow device.

[Explanation of symbols]

 1 Printed Circuit Board 2 Conveying Section 3 Heating Room 4 Heating Section 5 Cooling Section 6 Sirocco Fan 7 Duct 8 Coiled Heater 9 Slit-Shaped Nozzle 10 Rectifying Area 11 First Nozzle 12 Second Nozzle 13 Bottom Heating Section 14 Rail 15 Second Heater 16 Lower surface heating duct 17 Plate 18 First heater 19 Second heater 20 Atmosphere advancing direction 21 Fan

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Naoichi Chikisa 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (11)

[Claims] 1. A heating device having a carrying unit for mounting and carrying a printed circuit board, and a first heating means for heating and melting a solder paste on the printed circuit board to connect an electronic component to an electric circuit on the printed circuit board. Section, a cooling section having a cooling means for cooling the printed circuit board after heating, and a fan for compressing and blowing the atmosphere of the heating section and circulating the atmosphere in the furnace to form a path through which the atmosphere circulates. In addition, a reflow device, characterized in that a duct in which a first heater as a first heating means is arranged, and a rectifying region is provided between the duct outlet and the upper side of the printed circuit board transport section. 2. The reflow apparatus according to claim 1, wherein the ducts are arranged on the lower side and the inner side of the substrate transfer section. 3. The reflow apparatus according to claim 1, wherein the heating section includes a coil heater as the first heating means. 4. The reflow apparatus according to claim 1, 2 or 3, wherein two kinds of slit-shaped nozzles having different 90 ° directions with respect to the circulation direction of the atmosphere are alternately arranged as the rectifying region. 5. The reflow apparatus according to claim 4, wherein the wind velocity blown from the slit-shaped nozzle onto the upper surface of the printed circuit board is constant at 3 to 5 meters per second in the longitudinal direction of the slit opening. 6. The wind velocity blown onto the upper surface of the printed circuit board by the slit-shaped nozzle can be adjusted in the range of 1 to 10 meters per second in the longitudinal direction of the slit, and the gradient of the wind velocity can be freely adjusted. The reflow device according to claim 4. 7. Among the slit-shaped nozzles, each side on the nozzle inlet side is parallel to the direction in which the atmosphere circulates inside the furnace body, and is parallel to the wall of the outer edge of the atmosphere path. 5. The reflow apparatus according to claim 4, wherein the outermost side of the first nozzle arranged in the above is installed with a gap of about 5 to 50 mm from the wall surface. 8. A second heating means separate from the heating means, a lower surface heating for heating the printed circuit board by blowing a heated atmosphere from a lower surface of the printed circuit board to a lower side of a rail for conveying the printed circuit board. A lower surface heating duct that includes a section, which constitutes a path through which the atmosphere blown out from the lower surface heating section passes, and a second heater as a heating means, and a lower surface heating duct outlet arranged under the printed circuit board transport section, A reflow apparatus comprising: a plate having a plurality of hot air outlets on a plane parallel to a conveyance surface of the printed circuit board, in a direction parallel to the traveling direction of the printed circuit board and a direction perpendicular to the traveling direction of the printed circuit board. 9. A reflow apparatus in which a fan for circulating the atmosphere of the heating portion, a lower surface heating duct that constitutes a path through which the atmosphere circulates, and a first heater as a heating means are arranged in the lower surface heating duct. In Claim 8, the atmosphere blown out from the lower surface heating part is branched and supplied from the middle of the circulation path of the atmosphere of the heating part.
The reflow device described. 10. The second heater is arranged in a passage path of an atmosphere blown out from a lower surface heating section immediately below the plate, and the atmosphere blown out from a plurality of hot air blowing ports of the plate by the second heater is a lower surface. The reflow device according to claim 8 or 9, wherein the reflow device is arranged so that the temperature rises according to the length of passage in the heating duct. 11. The reflow apparatus according to claim 8, wherein the velocity of the hot air blown out from the nozzle of the lower surface heating unit is kept constant at 4 to 5 meters per second.