JPH10322013A - Method and equipment for reflow soldering - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cool a printed board even when the with of the printed wiring board is changed, in the case of performing reflow soldering while cooling the printed wiring board mounted with an electronic component having a low heat resistant temperature by blowing wool wind. SOLUTION: Transport conveyer 11 is composed of two conveyer frames in parallel. At the time of shifting one conveyer frame 72R in accordance with the width of a printed wiring board 1, the width of a cool wind blowing port 73 for blowing cool wind to the printed wiring board 1 is changed with the shift of the conveyer frame 72R. One of the cool wind blowing port 73 is composed of sliding plates 71 and 75, the conveyor frame 72R on the movable side is connected to the sliding plate 75 to allow the sliding plate 75 to shift together with the shift of the conveyor frame 72R. Thus, the width of the cool wind blowing port 73 is constituted so as to match with the width of the printed wiring board 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for reflow soldering 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 in which the solder is melted by heating in a heating furnace of the device to melt the solder in the portion to be soldered.

In a reflow soldering apparatus, since a printed wiring board is exposed to a high-temperature atmosphere, when an electronic component having a low heat-resistant temperature is soldered, 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 the heat-resistant temperature. A technique for performing reflow soldering is described. In these techniques, solder paste is supplied in advance not only to the soldered portions of the chip-type electronic components but also to the soldered portions of the lead-type electronic components, and the reflow soldering device is used to supply these soldered portions. This is a technology for batch reflow soldering.

[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. 6 and 7 are excerpts of the main parts of Japanese Patent Application No. 9-7649 filed by the present inventor. FIG. 6 is a side sectional view showing a conventional example of a reflow soldering apparatus, and FIG. FIG. 6 is a cross-sectional view of a heating section of No. 6;

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 an exhaust means for exhausting air is provided, furthermore, they are independently provided, 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 transport comprising a chain 12 which is a two-row rotating support which 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 and a suction / exhaust port 16L on the left side and a suction / exhaust port 16R on the right side for sucking and exhausting the atmosphere in the furnace body 10 from both sides 1a of the printed wiring board 1. , A suction / exhaust passage 17 and an exhaust means constituted by a blower 24 composed of a fan 25 and a motor 26 are provided. 27 is the printed wiring board 1
Is a carry-in port, and 28 is 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.

In FIG. 6, a 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, and a sensor provided on the surface of the panel heater 43 of the temperature equalizing section 33. 44 also detects the surface temperature of the panel heater 43. 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. 7, a printed wiring board 1 is placed on pins 20 of a chain 12 of a conveyor 11 and is supported and transported. At this time, the printed wiring board 1 conveys the portion to be soldered downward.

As shown in FIG. 7, 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. Solder paste 9
Has been applied.

The lower surface 1b of the printed wiring board 1 is controlled by an infrared heater 41 provided below the conveyor 11.
Is heated.

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 and exhaust ports 16L and 16R are provided on both sides 1a of the printed wiring board 1 on both sides thereof, that is, along the conveyor 11, and the blower passes through the suction and exhaust path 17 and the hose 19, respectively. 24 are connected to the suction port 18. And 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 heat of the lead-type electronic component 2B from the suction and exhaust ports 16L and 16R provided on both sides 1a of the printed wiring board 1 is actively sucked. 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.

In this case, basically, the outside air blowing amount Q ₁ and the suction exhaust air amount Q ₂ are adjusted to be substantially the same, or are adjusted so that the suction exhaust air amount Q ₂ slightly increases. However, when the number of mounted lead-type electronic components 2B is large, or when a component having a large shape is mounted on the upper surface 1c of the printed wiring board 1 and the amount of air blown by the outside air decreases, , may be adjusted to air volume Q ₁ as slightly larger than the suction exhaust air volume Q _2. That is, the balance between the blown air amount Q ₁ and the suction / exhaust air amount Q ₂ is appropriately adjusted according to the mounting state of the electronic component 2.

Further, the above-mentioned air blowing amount Q ₁ and the suction exhaust air amount Q
_{2 In} addition to adjusting the relative volume, the air volume Q ₁ and the suction air volume Q
By increasing or decreasing the absolute amount of _2, the lead type electronic component 2B
The degree of cooling can be adjusted. However, if the air volume Q ₁ and the suction air volume Q ₂ are excessively increased, the furnace body 10
Since the inner is too cold, in which case the reducing the absolute amount of air volume Q ₁ and the suction exhaust airflow Q _2.

As described above, the outside air is blown onto the upper surface side 1c of the printed wiring board 1, and the atmosphere inside the high temperature furnace body 10 which rises in temperature and rises above the conveyor 11 is 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 blown to 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.

The infrared heater 41 has a configuration in which a nozzle portion 55 is formed to blow hot air between the infrared heaters 41, and a horn portion 5 is provided at the tip of the nozzle portion 55.
6, a blower 5 comprising a fan 58 and a motor 59.
It is contemplated that the hot air supplied by 7 would dissipate and blow out over a wide area.

The atmosphere is heated by a fan 58 rotated by a motor 59 through a nozzle portion 55 formed between the infrared heaters 41 and blown out of a horn portion 56.
The printed wiring board 1 is sprayed onto the lower surface 1b of the printed wiring board 1 and heats the printed wiring board 1 and a portion to be soldered. Thereafter, the air is returned to the fan 58 through the circulation path 60 and circulated. Further, infrared rays are radiated from the infrared heater 41 to heat the printed wiring board 1 and its soldered portion. The current plate 61 is a means for uniformly distributing the flow of the hot air atmosphere.

In the temperature raising section 32, since the heating means of the hot air circulation system is used below the conveyor 11, the hot air easily rises to the upper side 1 c of the printed wiring board 1, that is, above the conveyor 11. . Therefore, outside air blown air volume Q ₁ to the hold down the increase of the hot air motor 23
Adjust the rotation speed of the. Also, the exhaust air flow rate Q ₂ is increased accordingly.

The reflow section 34 comprises only the heating means 15 below the conveyor 11 and the heating means 15 is of a hot air circulation type. That is, the hot air heated by the heater 48 of the heating chamber 47 is arranged so as to have a uniform flow by the rectifying plate 62, and is blown to the lower surface side 1b of the printed wiring board 1 to heat the printed wiring board 1 and its soldered portion. It is a configuration to do. 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.

[0033]

In the prior arts 1 and 2 or the technology of Japanese Patent Application No. 9-7649, the wind pressure of the hot air blown from the lower side 1b of the printed wiring board 1 is determined.
When the wind pressure of the cool air blown from the upper surface side 1c of the printed wiring board 1 is reflow soldered to the printed wiring board 1 having a small width, similarly to the case of performing the reflow soldering of the printed wiring board 1 having a large width. The inventor has found that there is no equilibrium. That is, when the width of the printed wiring board 1 is reduced, it is difficult to sufficiently cool the side end 1a.

That is, this is because the width of the opening of the conveyer 11 formed in two parallel strips changes according to the width of the printed wiring board 1, but the width of the outlet of the cool air is constant. I found something. That is, when the width of the printed wiring board 1 is reduced, cool air is blown to unnecessary portions,
In addition, the suction exhaust port 16R (16L) is the printed wiring board 1
Away from the side end portion 1a.

In FIG. 7, when the width of the printed wiring board 1 is narrow, the movable conveyor on the right movable side (parallel 2
Conveyor 11 of the strip conveyor 11
The illustration of the conveyor width variable mechanism is omitted.)
Is moved to the left in the figure, the right suction / exhaust port 16
R is far away from the right end 1a of the printed wiring board 1, and the suction force and the exhaust force acting on the right end 1a are reduced.

On the other hand, the rotational speed of the motor 23 of the blower 21 as the blowing means is adjusted to adjust the amount of air blow, and the rotational speed of the motor 26 of the blower 24 as the exhaust means is adjusted to adjust the amount of exhaust air. Is adjusted, the above-mentioned equilibrium point can be found as it is. However, since it is necessary to reset them every time the width of the printed wiring board 1 changes, the operation and setting work associated therewith become complicated.

An object of the present invention is to reflow soldering by preventing cool air from being blown out to unnecessary portions, and by always positioning suction and exhaust ports at side edges of a printed wiring board. Even when the width of the printed wiring board is reduced, it is possible to sufficiently cool the side ends thereof as in the case where the width of the printed wiring board is wide.

[0038]

According to the present invention, the width of the cool air outlet can be adjusted according to the width of the plate-like work to be soldered. Thereby, the wind pressure of the cold air can be effectively applied to the plate-like work to be soldered. And it is comprised so that a blowing width may be interlocked with the support width of a conveyance means.

Further, the suction and exhaust ports are located at both side ends of any plate-shaped work to be soldered having any width. Thereby, the wind pressure of the cool air is applied to the upper surface of the plate-like work to be soldered, and the suction force for exhausting and exhausting heat can be applied to both side ends of the plate-like work to be soldered. That is, the suction / exhaust port is configured to move in conjunction with the support width of the transport unit.

Further, if the cool air blowing means of the cool air blowing means and the means for adjusting the width of the cool air blowing means are detachable, the portion to which the flux fume is easily attached can be removed and the cleaning operation can be easily performed. Become.

[0041]

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

(1) Solder is supplied to the soldered portion of the printed wiring board in advance, the printed wiring board is transported into the furnace by a transport conveyor, and the surface on the soldered portion side is heated by a heater. In a reflow soldering apparatus that blows cold air with a blower that blows cold air to the other surface to melt and solder the solder of the portion to be soldered, a cold air blower that adjusts a width of a cool air blow port of a cool air blowing means is provided. Reflow soldering is performed by adjusting the width of the cool air blowing port by the width adjusting means in accordance with the width of the printed wiring board and performing soldering.

(2) A transport conveyor for transporting a printed wiring board to which solder is previously supplied to a soldered portion into a furnace, a heater for heating a surface of the soldered portion side, and a solderable portion of the printed wiring board. Cold air blowing means comprising a blower for blowing cold air to the other surface different from the attachment surface,
A reflow soldering apparatus that performs soldering by melting the solder of the portion to be soldered, wherein the cool air blowing means adjusts the width of the cool air outlet,
Support width adjusting means for adjusting the support width of the conveyor that supports and conveys both ends of the printed wiring board by means of a chain that rotates in two parallel lines, and supports the conveyor that is configured in two parallel lines. The width adjusting means and the cool air outlet width adjusting means are connected to each other, and the reflow soldering apparatus is configured to link the width of the cool air outlet in accordance with the adjustment of the support width of the conveyor.

(3) The soldered portion of the printed wiring board, to which solder has been supplied in advance, is heated by a heater from the lower side while being conveyed through the furnace inside the furnace with the soldered portion directed downward. In a reflow soldering apparatus for melting and soldering the solder of the soldered portion, a blowing means for blowing a cool air atmosphere outside the furnace body from above onto a surface on the upper side of the printed wiring board, and both sides of the printed wiring board. A blower for sucking the atmosphere inside the furnace body upward from the end side and exhausting the outside of the furnace body; a cool air blowing means having a means for adjusting a width of the cool air blowing port; A conveyor that supports and conveys both side ends of the printed wiring board by means of a rotating chain; It was ligated to form a reflow soldering apparatus in accordance with the regulation of the support width of the conveyor so as to synchronize the width of the cold air blowing port.

(4) In the reflow soldering apparatus of the above (2) or (3), the cool air blowing means of the cool air blowing means and the means for adjusting the width thereof are detachably provided.

[0046]

Next, specific examples of the reflow soldering method and apparatus according to the present invention will be described with reference to examples.

FIG. 6 is a side sectional view illustrating the whole of the reflow soldering apparatus according to the present invention. However, it is provided with a cool air outlet and a means for adjusting the width thereof, and the position of the suction and exhaust port is always located at the side end of the printed wiring board, and furthermore, these means are detachably configured. It is an advanced configuration in that it does.

This advanced configuration is basically the same in the temperature raising section, the temperature equalizing section, and the reflow section, and these are not necessarily required for each of the above sections, and are provided only in the reflow section or only in the temperature raising section. Can also be provided.

Therefore, in the present embodiment, an embodiment in a heating section will be described as an example. Then, the same configuration may be applied to the case where it is provided in other parts. In the prior art, a vertical cross-sectional view of the heating section is also shown as an example, and these can be easily compared.

FIG. 1 is a cross-sectional view showing one embodiment of the present invention, showing a temperature raising section 32, and the same reference numerals as those in FIG. 7 indicate the same parts. It should be noted that a side cross-sectional view showing the entirety will be described with reference to FIG. 6 as described above and also with reference to the cross-sectional view of FIG.

(1) Overall Reflow Soldering Apparatus That is, in the furnace body 10 of the reflow soldering apparatus,
There is provided a conveyor 11 composed of two parallel chains 12 for carrying while supporting and supporting both side ends 1a of the printed wiring board 1. Below this conveyor 11, a heating means 13 is provided. . Above the conveyor 11, the atmosphere of the cool air outside the furnace 10 is
A blower 21 is provided as a blower comprising a fan 22 and a motor 23 for blowing air into the furnace 10. Each suction / exhaust port 16 </ b> L sucks and exhausts the atmosphere in the furnace body 10 from both sides 1 a of the printed wiring board 1. , 16R, a suction / exhaust passage 17, and a blower 24 for exhaust.

In this reflow soldering apparatus, the preheating section 31 is composed of one chamber of the temperature raising section 32 and one chamber of the temperature equalizing section 33, and subsequently, one chamber of the reflow section 34 is provided. . The heating unit 13 of the temperature raising unit 32 is configured to use both infrared heating by the infrared heater 41 and hot air heating by the blower 57, and the heating unit 14 of the temperature equalizing unit 33 includes infrared heating by the panel heater 43 and a reflow unit 34. The heating means 15 has a configuration of hot air heating by a heater 48.

In FIG. 6, a 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, and a sensor provided on the surface of the panel heater 43 of the temperature equalizing section 33. 44 also detects the surface temperature of the panel heater 43. That is, a temperature control device (not shown) adjusts the power supplied to the infrared heater 41 and the panel heater 43 so as to reach a predetermined temperature by referring to the temperature detection results of these sensors 42 and 44.

A sensor 46 provided at the hot air outlet 45 of the reflow section 34 is a sensor for detecting hot air temperature.
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.

(2) Example of a mechanism for adjusting the width of the cool air blow port and the position of the suction / exhaust port Next, a description will be given with reference to a cross-sectional view of the heating section in FIG. The printed wiring board 1 is the same as that shown in FIG. 7 and will be described with reference to FIG.

The printed wiring board 1 is placed on the pins 20 of the chains 12 of the conveyor 11 and is supported and transported. At this time, the printed wiring board 1 conveys the portion to be soldered downward.

As shown in FIGS. 1 and 7, the printed wiring board 1 has a chip-type electronic component 2A mounted on its lower surface 1b, 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 1c of the printed wiring board 1, and the lead wire 2B
a is inserted through the printed wiring board 1, and a solder paste 9 is applied to a portion to be soldered on the lower surface side 1 b of the printed wiring board 1. This technology is disclosed in Japanese Patent No.
And Japanese Patent No. 2502827 and Japanese Patent Application No.
No. 7649.

Then, the heating means 13 using the hot air from the infrared heater 41 and the blower 57 provided below the conveyer 11, and the lower side 1b of the printed wiring board 1 is used.
Is heated. The heating means 13 includes an infrared heater 41
A nozzle portion 55 for blowing hot air is formed therebetween, and a horn portion 56 is provided at the tip of the nozzle portion 55.
It is considered that hot air is diffused and blown out over a wide area.

The atmosphere in the heating section 32 is heated by a fan 58 rotated by a motor 59 of a blower 57 through a lower nozzle section 55 formed between the infrared heaters 41 and blown out of a horn section 56 to form a printed wiring. The printed wiring board 1 and its soldered portion are heated by being sprayed on the lower surface side 1b of the board 1. Thereafter, the air is returned to the fan 58 through the circulation path 60 and circulated. In addition, the infrared heater 4
Infrared rays are radiated from 1 to heat the printed wiring board 1 and its soldered portion. The current plate 61 is a means for uniformly distributing the flow of the hot air atmosphere.

On the other hand, a fan 22 and a motor 23 for driving the fan 22 are provided above the conveyor 11 so that the atmosphere of the cool air outside the furnace body 10, that is, the outside air is applied to the upper surface 1c of the printed wiring board 1. It is configured to spray. The opening 51 is an outside air intake provided in the furnace body 10, and the rectifying plate 52 is for equalizing the air blow by the fan 22.

Further, suction / exhaust ports 16L and 16R are provided on both sides 1a of the printed wiring board 1, that is, on both sides thereof along the conveyor 11, and the blower passes through the suction / exhaust passage 17 and the hose 19. 24 are connected to the suction port 18. The exhaust port 53 of the blower 24 is open to the outside.

The sliding plate 7 provided on the conveyor 11
Reference numerals 1 and 75 denote members for partitioning the atmosphere between the lower side and the upper side of the conveyor 11, and a partition plate 5 provided on the wall of the furnace body 10.
4 is brought into sliding contact with the conveyor frame 72 on the right side in the figure.
R is configured to move in the left-right direction. In addition,
The left conveyor frame 72L is fixed. That is, the width of the conveyor 11 supporting the printed wiring board 1 can be changed.

On the other hand, the opening 5
The outside air supplied from 1 by the fan 22, that is, the cool air, is guided to the cool air outlet 73 constituted by the partition plate 54 and the sliding plate 75. The upper slide plate 75 and the conveyor frame 72R on the movable side of the conveyor 11 are connected by connecting columns 74 as connecting means, and when the support width of the conveyor 11, that is, the width for supporting the printed wiring board 1 is adjusted. The sliding plate 75 forming the cool air outlet 73 also moves together with the partition plate 54 while slidingly contacting the partition plate 54, and operates so that the width of the cool air outlet 73 becomes the same as the width of the printed wiring board 1. Reference numeral 76 denotes a chain cover.

In addition, the suction force of the exhaust blower 24 always acts on the side end 1a of the printed circuit board 1 even if the width of the printed circuit board 1 is different, even if the width of the printed circuit board 1 is different. That is, the right suction / exhaust port 16R
Are always located in the upper part of the right conveyor frame 72R. The left conveyor frame 72L
Are fixed, so the left suction / exhaust port 16L is also fixed.

That is, the width of the cool air outlet 73 is adjusted according to the width of the printed wiring board 1, and the wind pressure can be effectively applied to the entire area of the printed wiring board 1. Also,
The suction / exhaust ports 16L and 16R provided through the suction / exhaust passage 17 in communication with the blower 24 are always provided at the side end 1a even if the type of the printed wiring board 1 changes or its width changes. Will be located.

With this configuration, even when the width of the printed wiring board 1 is reduced due to a decrease in the width of the printed wiring board 1, an electronic component having a low heat-resistant temperature mounted on the upper surface 1c of the printed wiring board 1, for example, The outside air is blown onto the lead-type electronic component 2B to deprive it of heat and suppress a rise in temperature. Then, the outside air whose temperature has risen by depriving the lead-type electronic component 2B of heat is
The suction and exhaust ports 16L and 16R provided on both sides 1a of the printed wiring board 1 can positively suck and discharge the printed wiring board.

The outside air is blown onto the upper surface 1c of the printed wiring board 1 so that
Of the printed wiring board 1 while suppressing the high-temperature atmosphere that is going to rise from the lower side of the printed wiring board 1.
The high temperature atmosphere that is going to rise from the side a is sucked and discharged in the lateral direction outside from both side ends 1a of the printed wiring board 1. Therefore, the lead-type electronic component 2B mounted near the side end 1a of the upper surface 1c of the printed wiring board 1 is not heated by the high temperature atmosphere rising from below.

Note that, as shown in FIG.
Are both conveyor frames 72L, 7 of the conveyor 11
It is also important that the printed wiring board 1 is configured to penetrate into a recessed portion with the printed wiring board 1 as the bottom by 2R. As a result, the descending cool air comes into contact with the printed wiring board 1 and the lead-type electronic component 2B and then rises once and is sucked into the suction / exhaust ports 16L and 16R, thereby increasing the cool air pressure in the relevant portions. is there.

With the above configuration, even if the type of the printed wiring board 1 on which the reflow soldering is performed is changed, and even if the width of the printed wiring board 1 is changed and the support width of the conveyor 11 is changed, a stable cold air pressure is always maintained. It can act on the upper surface side 1c of the plate 1. Further, the suction / exhaust ports 16L and 16R for exhausting heat can be always located on both sides 1a of the printed wiring board 1.

Therefore, even if the width of the printed wiring board 1 changes, the lead-type electronic component 2B mounted on the upper surface 1c of the printed wiring board 1 must always be stably cooled to support the temperature below the heat resistant temperature. Will be able to

(3) Removable cold air blow port and its adjusting means The cold air blow port 73 has a low temperature (about the same level as or slightly higher than that) due to the atmosphere outside the furnace body 10, that is, the outside air (cold air). Lower than the reflow temperature). Therefore, flux fume easily adheres to the vicinity of the cold air blow port 73. That is, the flux fume generated when the solder 9 applied to the printed wiring board 1 is heated by the paste 9 is contacted with cold air and atomized (liquefied).

Therefore, it is desirable that the cold air blow port 73 can be easily attached and detached. That is, the cleaning operation can be easily performed. FIGS. 2 to 5 show such a cool air blow-off unit for blowing outside air, that is, cool air.
Shown in

FIG. 2 is a perspective view showing the entire structure of the cool air blow-off unit. FIG. 3 is a cross-sectional view taken along the line II of FIG. 2, FIG. 4 is a cross-sectional view taken along the line II-II of FIG. 2, and FIG. 5 shows an embodiment in which the cold air blowing unit of FIG. FIG.

That is, as shown in FIG. 2, an outside air guide cylinder 82 is provided on the arm 81, and a shutter plate 84 and a cold air blow port 73 which expand and contract in a “<” shape by a hinge 83 are formed in the outside air guide cylinder 82. The movable-side outlet plate 85 is provided. Note that the fixed-side outlet plate 86 is connected to the outside air guide cylinder 82.
Is extended downward.

That is, the fixed-side blow-off plate 86 and the movable-side blow-out plate 85 form the cool-air blow-out port 73, and the width of the cool-air blow-out port 73 is adjusted by moving the movable-side blow-out plate 85 in parallel. It is a mechanism. The outside air guide tube 82 is configured to have a size to be connected to an outside air blow tube 98 provided on the side of the fan 22 that blows outside air in FIG. Also, arm 8
Reference numeral 1 denotes a member that is attached to the frame 99 or the furnace body 10 of the reflow soldering apparatus as shown in FIG. This is a mechanism in which a coupling hole (shown in FIG. 2) 96 provided in the arm 81 is fitted and fixed to a pin provided in the frame 99 or the furnace body 10 of the reflow soldering apparatus.

As shown in FIG. 3 and FIG. 4, a cool air outlet 73 is provided with a wind direction adjusting plate 87. In this example, cool air is collected at the center of the heating zone, that is, so as not to dissipate. The direction of the wind direction adjusting plate 87 is determined.

For this purpose, the movable blower plate 85 is configured to move through the wind direction adjusting plate 87, and the movable blower plate 85 is provided with a hole 88 through which the wind direction adjusting plate 87 penetrates. . The wind direction adjusting plate 87 is fixed to the outside air guide cylinder 82.

On the other hand, as shown in FIG. 3 and FIG.
0 is provided. On the other hand, a roller 89 is provided on a support plate 91 provided on the movable-side outlet plate 85, and when the roller 89 travels in the traveling guide 90, the movable-side outlet plate 85 becomes a fixed-side outlet plate 86. In contrast, it is a mechanism that opens and closes while maintaining parallelism.

Further, as shown in FIG. 4, a conveyor connecting plate 92 is provided on the support plate 91 of the roller 89 provided on the movable-side outlet plate 85.
3 is a pin 94 provided on the movable conveyor frame 72R.
And the support plate 91 and, consequently, the movable-side blower plate 85 move in accordance with the movement of the movable-side conveyor frame 72R in the horizontal direction in the figure according to the width of the printed wiring board 1. It is.

That is, as is clear from FIG. 4, the movable conveyor frame 72R is moved in the left-right direction in the figure (by a not-shown variable conveyor width mechanism) to adjust the support width of the printed wiring board 1. The movable-side blow-off plate 85 moves together with it, and even if the type of the printed wiring board 1 changes and its width changes, the side end portion 1 of the printed wiring board 1
The movable-side outlet plate 85 also moves in accordance with the position a, and maintains a constant relative position.

Therefore, the outside air, that is, the width of the cold air blow port 73 is automatically set according to the width of the printed wiring board 1, and the suction / exhaust port 16R is always located near the side end 1a of the printed wiring board 1. Become like Therefore, even if the type of the printed wiring board 1 changes and its width changes, cool air having a stable wind pressure is always blown to the printed wiring board 1 and the mounted lead-type electronic components 2B and the like, and the exhaust after cooling is completed. The heat is sucked from both sides 1 a of the printed wiring board 1 and exhausted, and finally exhausted from the blower 24 to the exhaust port 53.

As shown in FIG. 5, the cool air blow-off unit 80 can be easily attached and detached by fitting it to a guide pin 95 provided on the frame 99 or the furnace body 10 of the reflow soldering apparatus. Configuration.

That is, in FIG. 5, a hole (shown in FIG. 2) 96 provided in the arm 81 of the cold air blow-off unit 80 is fitted to a pin 95 provided in the furnace body 10 and is also provided in the conveyor connecting plate 92. The holes (shown in FIG. 4) 93 are fitted to pins 94 provided on the conveyor frame 72R. Then, the outside air, that is, the cool air blowing means (the fan 22, the motor 23, the outside air blower 98, etc.) and the suction / exhaust means (the suction / exhaust passage 17, the hose 19, etc.) are lowered around the hinge 100 as the rotation center, and With the heating means 13.

A hood connecting plate (see FIG. 2) 97 provided in the cool air blow-off unit 80 is a means for facilitating connection with the outside air blower cylinder 98 shown in FIG.

With this configuration, the cool air blow-off unit 80 can be easily attached and detached, and cleaning, maintenance, and inspection thereof can be easily performed.

[0086]

As described above, according to the first aspect of the present invention, it is possible to apply a cold air pressure by blowing cold air in accordance with the width of the printed wiring board, and the width of the printed wiring board is reduced. Even if the temperature changes, it is possible to stably suppress a rise in the temperature of the side surface on which the cold air is blown.

According to a second aspect of the present invention, the width of the supporting conveyor is adjusted in accordance with the width of the printed wiring board, and the width of the cool air outlet is also adjusted in accordance with the width of the conveying conveyor. It will be set in conjunction with the width of the board. As a result, the effect of claim 1 can be realized in a comfortable operation environment of the reflow soldering apparatus.

According to the third aspect of the present invention, the position of the suction / exhaust port for exhausting heat can be always printed in addition to the ability to apply the wind pressure of the cool air blown according to the width of the printed wiring board. Since it can be located at both ends of the wiring board, even if the width of the printed wiring board changes, the temperature rise on the side surface of the cold air blow can be more stably suppressed. In particular, the effect becomes remarkable at the end of the printed wiring board, and the electronic component having a low heat-resistant temperature mounted on the side end can be protected from thermal stress.

According to the fourth aspect of the present invention, since the portion of the cool air outlet can be easily attached and detached, cleaning work and maintenance /
Inspection work can be performed easily, and the operating environment of the reflow soldering apparatus can be made favorable and excellent.

[Brief description of the drawings]

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

FIG. 2 is a perspective view illustrating a blow unit for cool air.

FIG. 3 is a sectional view taken along line II of FIG. 2;

FIG. 4 is a sectional view taken along line II-II of FIG.

FIG. 5 is a cross-sectional view showing a mode in which the cold air blow-off unit of FIG. 2 is mounted on a reflow soldering apparatus.

FIG. 6 is a side sectional view showing a conventional example of a reflow soldering apparatus.

FIG. 7 is a cross-sectional view of the heating unit of FIG. 6;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Printed wiring board 1a Side end 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 Conveyor conveyor 12 Chain 13 Heating means 16L Suction / exhaust port 16R Suction Exhaust port 17 Suction exhaust path 21 Blower 24 Blower 31 Preheating section 32 Heating section 33 Equalizing section 34 Reflow section 41 Infrared heater 51 Opening 53 Exhaust port 57 Blower 71 Sliding plate 72L Conveyor frame 72R Conveyor frame 73 Cold air blowing port 74 Connecting column 75 Sliding plate 80 Cold air blow unit 81 Arm 82 Outside air guide tube 83 Hinge 84 Shutter plate 85 Movable blow plate 86 Fixed blow plate

Claims (4)

[Claims] 1. A method according to claim 1, wherein solder is supplied in advance to a portion to be soldered of the plate-like work to be soldered, and the plate-like work to be soldered is transported into a furnace by a transport means. Reflow soldering, in which the other side of the plate-like work to be soldered is blown with cold air by means of a cold air blowing means while the side face is heated by a heating means to melt the solder in the soldered portion and perform soldering. In the method, the width of the cold air outlet by the cold air outlet width adjusting means for adjusting the width of the cold air outlet of the cold air blowing means is adjusted in accordance with the width of the plate-like work to be soldered, and soldering is performed. A reflow soldering method characterized by the following. 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 side of the plate-like work to be soldered, which is different from the surface to be soldered, which is heated by means, Width adjusting means for adjusting the supporting width of the conveying means for conveying and supporting both side ends of the plate-like work to be soldered by two parallel rotating supports. A reflow soldering apparatus, comprising: means for adjusting a width of a cool air blow port interlocked with adjustment of the support width adjusting means. 3. A transporting means for transporting a plate-shaped work to be soldered in which solder is previously supplied to a soldered portion in a furnace with a soldered portion directed downward, and said plate-shaped soldered work. A reflow soldering apparatus that includes a heating unit that heats from a lower side of the work and performs soldering by melting the solder of the soldered portion; Blowing means for blowing a cool air atmosphere outside the furnace body, and exhaust means for sucking a high-temperature atmosphere inside the furnace body upward from both side end sides of the plate-like work to be soldered and exhausting the outside of the furnace body. Cold air blowing means, and the cold air blowing means is provided with a cold air blowing port width adjusting means for adjusting the width of the cold air blowing port. Transport means for supporting and transporting both ends of the soldering work, and adjusting the width of the cool air outlet in accordance with the adjustment of the support width of the transport means, and adjusting the width of the cool air outlet and the width of the cool air outlet. A reflow soldering apparatus, wherein the reflow soldering apparatus is connected to a means. 4. The reflow soldering according to claim 2, wherein the cool air blower of the cool air blower and the adjusting means for adjusting the width of the cool air blower are detachably provided. apparatus.