JPH07249859A - Cooling device of reflowed board - Google Patents

Abstract

PURPOSE:To improve a cooling device of a reflowed board in cooling efficiency by a method wherein sirocco fans are arranged so as to make their suction openings confront each other at the lower parts of vertical cooling coils through the intermediary of a space under a conveyer, and fan casings are provided to guide flows of air induced by the fans to the air outlets of the casings which confront each other at the upper part of the cooling coils. CONSTITUTION:When a flow of air heated passing through a substrate P is sucked into the suction opening 16 of a sirocco fan 15 passing through the lower part 13a of a vertical cooling coil 13 via a space below a conveyer 12, a flow of air of comparatively high temperature is cooled down by the cooling coil 13 to a flow of air of lower temperature. A flow of cold air discharged out from the circumferential face of the sirocco fan 15 is collected by a fan casing 17, guided to an upper air outlet 19 cooling the casing 17, and discharged out into a space above the conveyer 12 through the upper part 13b of the vertical cooling coil 13, when the flow of air is cooled down again by the vertical cooling coil 13 and straightened by fins 14. By this setup, a cooling device of this constitution can be improved in cooling efficiency.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflowed substrate cooling device for cooling a high temperature substrate which has been reflow-soldered in a reflow furnace such as a nitrogen reflow device or an air reflow device.

[0002]

2. Description of the Related Art As shown in FIG. 4, in a conventional reflowed substrate cooling device, a substrate transfer conveyor 2 is inserted into a cooling chamber body 1, and a fan 3 and a fan drive motor 4 are provided above the cooling chamber body 1. Is provided, and the cooling coils 5 are horizontally arranged above and below the substrate transport conveyor 2.

The air generated by the fan 3 in the cooling chamber body 1 is cooled by the cooling coil 5 to become cold air, which is circulated or stirred. A component-mounted printed wiring board (hereinafter, simply referred to as a board P) that has been heated to a high temperature by a soldering process in a reflow device located in the preceding stage of the cooling device.
When is carried into the cooling chamber body 1 by the conveyor 2, the substrate P is cooled by the cold air.

In the former reflow apparatus, since the flux gas generated from the solder paste applied to the substrate P is filled in the reflow furnace body, this flux gas is continuously placed in the cooling chamber body. It also penetrates into 1.

[0005]

The flux gas in the cooling chamber body 1 is condensed and liquefied when it comes into contact with the cooling coil 5, but since the cooling coil 5 is arranged above and below the substrate transfer conveyor 2, There is a problem that the liquefied flux in the cooling coil 5 of FIG.

Further, the cooling coil 5 on the substrate becomes a kind of obstacle for the cold air and lowers the wind speed of the cold air blown on the substrate, so that there is a problem that the cooling effect is reduced accordingly.

Further, the cooling coil 5 and the cooling chamber body 1
The liquefied flux on the inner wall surface of the chamber hangs down and collects on the bottom surface of the cooling chamber body 1. However, this flux recovery process is not easy and maintenance such as cleaning is difficult.

The present invention has been made in view of the above circumstances, and provides a reflowed substrate cooling device having a structure capable of collecting flux that is liquefied by a cooling coil so as not to be applied to the substrate and improving the cooling effect. The purpose is to do.

[0009]

According to a first aspect of the present invention, there is provided a reflowed substrate for cooling a high temperature substrate, which has been subjected to a reflow soldering process by a reflow device, by cold air circulated in a cooling chamber body. In the cooling device, a vertical cooling coil vertically arranged on at least one side of a conveyor that conveys a substrate and a suction port on the lower side of the vertical cooling coil on the opposite side to the space below the conveyor. Cooling of reflowed substrate characterized by a sirocco fan and a fan casing that guides the wind generated by this sirocco fan to the outlet facing the upper part of the vertical cooling coil connected to the space above the conveyor It is a device.

According to a second aspect of the present invention, in the apparatus for cooling a reflowed substrate according to the first aspect, a cool air accelerating nozzle is provided above the conveyor.

According to a third aspect of the present invention, in the apparatus for cooling a reflowed substrate according to the first aspect, a bottom portion of the cooling chamber body is provided with an inclination, and a flux collecting container is externally provided at a lowest level portion of the bottom portion. This is a configuration that is more detachably provided.

[0012]

According to the invention described in claim 1, by sucking air from the space below the conveyor through the lower part of the vertical cooling coil to the suction port of the sirocco fan, the heated high temperature substrate cools the heated air. Furthermore, the cool air discharged from the peripheral surface of this sirocco fan is guided to the air outlet facing the upper part of the vertical cooling coil by the fan casing, and is discharged to the space above the conveyor through the upper part of the vertical cooling coil to cool it again. To do. The cool air descends in the cooling chamber body, cools the substrate being conveyed by the conveyor, and circulates to the space below the conveyor. The flux contained in the cold air and liquefied on the vertical cooling coil and the inner wall surface of the fan casing flows down to the bottom portion of the cooling chamber main body by its own weight.

According to the second aspect of the present invention, the cooling effect is enhanced by accelerating the cold air by the cold air accelerating nozzle and blowing it onto the substrate.

According to the third aspect of the present invention, the flux that has dropped by gravity along the inner wall surface of the vertical cooling coil or the fan casing to the bottom portion of the cooling chamber body is further inclined due to the inclination of the bottom portion of the cooling chamber body. Move it by its own weight until it is collected. The flux recovery container is removed and the internal flux is processed.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the embodiments shown in FIGS.

1 and 2 show an embodiment of the present invention. In FIG. 1, a substrate transfer conveyor 12 for transferring a substrate P is inserted in a cooling chamber body 11, and the conveyor 12 is vertically mounted on both left and right sides. A vertical cooling coil 13 having a flat shape is arranged in the direction. The cooling coil 13 is provided with many fins 14 for absorbing heat. The fins 14 also have a function of rectifying the wind.

A sirocco fan 15, which is a type of centrifugal fan, is arranged on the opposite side of the space below the conveyor 12 via the lower portion 13a of the vertical cooling coil 13 and its suction port 16
Are facing each other.

This sirocco fan 15 and a fan casing for guiding the wind generated by the sirocco fan 15 upward
17 are provided on both left and right side surfaces of the cooling chamber body 11. A fan casing 17 formed separately from the cooling chamber body 11
Is necessary to increase the blowing efficiency of the sirocco fan 15.

A fan drive motor 18 is provided on the outer surface of the fan casing 17. This fan drive motor
By adjusting the number of rotations of 18, the air volume of the air circulated in the cooling chamber body 11 is adjusted.

An air outlet 19 is provided on the upper part of the fan casing 17, and the air outlet 19 is an upper portion 13b of the vertical cooling coil 13.
And is connected to the space above the conveyor 12 via the upper portion 13b of the vertical cooling coil 13.

A cool air accelerating nozzle 21 is provided above the substrate carrying conveyor 12. This cold air accelerating nozzle 21 has a large number of inverted V-shaped members 24 arranged in the lower portion of a frame member 23 having a ventilation opening 22 as shown in FIG. A cold air outlet 25 is provided between each inverted V-shaped member 24, and each inverted V-shaped member 24 is shown in FIG.
As shown in FIG. 3, it is formed to be long so that it can accommodate the maximum adjustment width of the conveyor 12.

Further, as shown in FIG. 1, the cooling chamber body
The bottom surface 11a of 11 is provided with a slope descending from the center toward both left and right sides, and a flux recovery port 31 is provided at the lowest level part (left and right side parts) of this sloped bottom surface part 11a. The flux collection container 32 is detachably fitted from the outside.

Next, the operation of this embodiment will be described. The substrate P, which has been heated to a high temperature by the reflow soldering process in the reflow device positioned in front of the cooling device, is conveyed by the conveyor.
The reflowed substrate P is carried into the cooling chamber body 11 by 12 and cooled by the cool air circulated in the cooling chamber body 11.

At this time, the wind whose temperature has risen after passing through the substrate P is discharged from the space below the conveyor 12 to the lower portion of the vertical cooling coil 13.
When the air is sucked into the suction port 16 of the sirocco fan 15 through 13a, the relatively high temperature air is cooled by the vertical cooling coil 13 and becomes cold air.

The cool air discharged from the peripheral surface of the sirocco fan 15 is collected by the fan casing 17, is guided to the upper air outlet 19 while cooling the fan casing 17, and passes through the upper portion 13b of the vertical cooling coil 13 to convey it. When it is discharged into the upper space of 12, this wind is regenerated by the vertical cooling coil 13
And is rectified by the fins 14 of the cooling coil 13.

The cold air thus cooled and rectified has a cold air accelerating nozzle 21 located in the upper part of the cold air chamber body 11.
Then, it is throttled by this nozzle 21 and the speed is increased. The cold air whose wind speed has increased in this way is blown onto the upper surface of the substrate being conveyed by the conveyor 12, effectively cooling this substrate P and circulating it to the space below the conveyor 12. By repeating the above, the air is circulated to cool the substrate P.

Next, when the substrate P sent from the reflow furnace to this cooling device enters the cooling chamber body 11, it cools the inert gas (nitrogen gas) containing the gaseous flux in the reflow furnace. Bring it in the chamber body 11. This flux-containing gas is supplied to the vertical cooling coil 13 by the sirocco fan 15.
It is liquefied at the stage of being sucked through the lower portion 13a and at the stage of rising in the fan casing 17.

The flux thus liquefied on the inner wall surfaces of the vertical cooling coil 13 and the fan casing 17 flows down to the bottom surface portion 11a of the cooling chamber body 11 by its own weight, and the bottom surface portion 11a is inclined by the inclination of the bottom surface portion 11a. It moves to the flux collecting container 32 by its own weight and is collected in this container. The flux recovery container 32 is regularly removed to process the internal flux.

FIG. 2 shows an example in which two sirocco fans 15 are provided on each side, four on each side, while FIG. 3 shows an example in which one sirocco fan 15 is provided on each side, two in total. Therefore, it is advisable to change such a configuration according to the size of the substrate P.

[0030]

According to the first aspect of the present invention, since the vertical cooling coil is vertically arranged on at least one side of the substrate transport conveyor, the flux liquefied by the cooling coil spills on the substrate. There is no danger of falling. Further, the wind is efficiently cooled by the vertical cooling coil at the suction port and the blowout port of the sirocco fan, and this wind provides a high cooling effect.

According to the second aspect of the present invention, the cooling air can be accelerated by the cooling air accelerating nozzle on the upper side of the conveyor and sprayed onto the substrate, so that the cooling effect can be enhanced.

According to the third aspect of the present invention, the flux liquefied on the vertical cooling coil or the inner wall surface of the cooling chamber body is guided along it to the bottom surface portion of the cooling chamber body, Due to the inclination, the flux can be easily collected into the flux collecting container by its own weight, and the collected flux can be easily processed by removing the flux collecting container, and the maintenance can be easily performed.

[Brief description of drawings]

FIG. 1 is a cross-sectional view in a width direction showing an example of a reflowed substrate cooling device according to the present invention.

FIG. 2 is a cross-sectional view of the same cooling device in the substrate transfer direction.

FIG. 3 is a cross-sectional view in the substrate transport direction showing a modified example of the same cooling device.

FIG. 4 is a cross-sectional view showing a conventional cooling device for a reflowed substrate.

[Explanation of symbols]

 P substrate 11 Cooling chamber body 11a Bottom part 12 Conveyor 13 Vertical cooling coil 13a Lower part 13b Upper part 15 Sirocco fan 16 Suction port 17 Fan casing 19 Blow-out port 21 Cold air accelerating nozzle 32 Flux recovery container

Claims (3)

[Claims] 1. A reflowed substrate cooling device for cooling a high-temperature substrate, which has been reflow-soldered by a reflow device, with cold air circulated in a cooling chamber body, wherein at least one side of a conveyor that conveys the substrate. Vertically arranged cooling coils, a sirocco fan whose suction port faces the lower space of the vertical cooling coil on the opposite side to the space below the conveyor, and the wind generated by this sirocco fan. And a fan casing that guides the fan to an outlet facing the upper part of a vertical cooling coil that is continuous with the space above the conveyor. 2. The cooling device for a reflowed substrate according to claim 1, wherein a cool air accelerating nozzle is provided on the upper side of the conveyor. 3. A slope is provided on the bottom surface of the cooling chamber body,
The flux collecting container is detachably provided from the outside at the lowest level portion of the bottom surface portion.
A cooling device for the reflowed substrate described.