JP2005014074A - Reflowing plant - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reflowing plant by which the temperature in a reflow heating part of a furnace body can be lowered in a short time, and the sticking of flux gas in the reflow heating part can be prevented. <P>SOLUTION: In the outside of a furnace body 11 reflow-heating a work W at a reflow heating part 13, a circulation system 26 of discharging a high temperature atmosphere from the reflow heating part 13 to the outside and thereafter returning the same to the furnace body 11 is provided. In the circulation system 26, a cooling means 28 of cooling a high temperature atmosphere is allowed to be existed. The cooling means 28 comprises a cooling condenser 31 of receiving the feed of cooling water and liquefying flux in a vaporized state. The flow rate of the cooling water to be fed to the cooling condenser 31 is controlled by a motor operated valve 36 operated in accordance with an electric signal. The temperature of circulation wind after being passed through the cooling condenser 31 is detected by a temperature sensor 41. A temperature indication controller 42 which receives the detected temperature of the circulation wind from the temperature sensor 41 controls the flow rate of the cooling water in the motor operated valve 36 in such a manner that the detected temperature is controlled to the one set by the temperature indication controller 42. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a reflow apparatus for cooling a high temperature atmosphere.
[0002]
[Prior art]
There is a reflow apparatus in which a cooling means for cooling a high-temperature atmosphere is provided in a reflow heating section of a furnace body for reflow heating a work so that the work temperature profile during reflow heating can be more finely controlled (see, for example, Patent Document 1). ).
[0003]
[Patent Document 1]
Japanese Unexamined Patent Publication No. 2000-188466 (first page, FIG. 1)
[0004]
[Problems to be solved by the invention]
In the case where the cooling means is provided in the reflow heating section of the furnace body, the flux is condensed and solidified in the furnace body and may adhere to the furnace body.
[0005]
This invention is made in view of such a point, and provides the reflow apparatus which can lower | hang the temperature in the reflow heating part of a furnace body in a short time, and can prevent adhesion of the flux gas in a reflow heating part. It is for the purpose.
[0006]
[Means for Solving the Problems]
According to the first aspect of the present invention, there is provided a furnace body having a reflow heating section for reflow heating the work, and a circulation which is provided outside the furnace body and is taken out from the reflow heating section and then returned to the furnace body. A reflow apparatus comprising a cooling system for cooling a high-temperature atmosphere interposed in the circulation system, and the cooling for cooling the high-temperature atmosphere in the reflow heating unit in the circulation system provided outside the furnace body Since the means is interposed, the atmosphere temperature in the reflow heating section can be lowered in a short time according to the work, and at this time, the high temperature atmosphere is cooled by the circulation system provided outside the furnace body. Therefore, it is possible to prevent the flux in the atmosphere from being liquefied and adhering to the furnace body during this cooling.
[0007]
According to a second aspect of the present invention, in the reflow apparatus according to the first aspect, the control means for making the cooling capacity of the cooling means larger than usual when the lowering range of the ambient temperature is equal to or higher than a desired settable temperature. When the reduction range of the ambient temperature is large, the control means increases the cooling capacity of the cooling means more than usual, so the high temperature ambient temperature in the reflow heating section can be automatically reduced in a short time. Can do.
[0008]
A third aspect of the present invention is the reflow apparatus according to the first or second aspect, further comprising a flux recovery means for recovering the flux condensed from the circulating air cooled by the cooling means. The recovery means can recover the flux contained in the high-temperature atmosphere in the furnace body, and at that time, the high-temperature atmosphere is cooled in the circulation system outside the furnace body, so that the liquefied flux can be prevented from adhering to the furnace body. .
[0009]
According to a fourth aspect of the present invention, the cooling means in the reflow apparatus according to any one of the first to third aspects receives a supply of cooling water and liquefies the vaporized flux and supplies the cooling condenser A flow rate adjusting valve for adjusting the flow rate of the cooling water, a temperature sensor for detecting the temperature of the circulating air after passing through the cooling condenser, and the temperature of the circulating air detected by the temperature sensor at a set temperature. A temperature adjusting means for adjusting the flow rate of the cooling water of the flow rate adjusting valve so as to control the circulation after passing through the cooling capacitor in the atmospheric temperature lowering control and flux recovery control in the furnace body. The temperature of the wind is detected by the temperature sensor, and the temperature set in the temperature adjusting means is set as a target value. By adjusting the flow rate adjustment valve to match the temperature and controlling the circulation rate of the cooling water, the temperature of the circulating air can be feedback-controlled with high accuracy, and the flux gas liquefaction temperature varies depending on the soldering material used. it can.
[0010]
According to a fifth aspect of the present invention, there is provided a filter in which the circulation system in the reflow device according to any one of the first to fourth aspects removes a flux in the circulating air, and a blowing means provided on the downstream side of the filter. Since the circulating air from which the flux mist and the like have been removed by the filter is sucked into the air blowing means, it is possible to prevent the flux from adhering to the air blowing means.
[0011]
According to a sixth aspect of the present invention, the circulation system in the reflow apparatus according to the first to fifth aspects comprises a heating unit disposed downstream of the cooling means. The temperature change in the reflow heating unit can be reduced by heating the circulating air returned to the reflow heating unit and raising the temperature to the ambient temperature of the reflow heating unit.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the first embodiment shown in FIGS. 1 and 2 and the second embodiment shown in FIG.
[0013]
First, the first embodiment shown in FIGS. 1 and 2 will be described. As shown in FIG. 2, the reflow apparatus is preheated to preheat the workpiece W inside the furnace body 11. A part 12, a reflow heating part 13 for reflow heating the work W, and a work cooling part 14 for cooling the work W are provided. A conveyor 15 is disposed so as to pass through the preheat heating unit 12, the reflow heating unit 13, and the workpiece cooling unit 14 and engage and convey the workpiece W to endless chains on both sides.
[0014]
The preheat heating unit 12 includes a heater 16, a fan 17, and a temperature sensor 18 on the upper side and the lower side of the conveyor 15. The reflow heating unit 13 has a heater 21, a fan 22, and a temperature sensor 23 that are heated to a higher temperature than the preheat heating unit 12 on the upper side and the lower side of the conveyor 15. Radiant heat from the heater 21 and the fan 22 are heated. The workpiece W is heated by a high-temperature atmosphere that has become a relatively high-temperature hot air. Further, the workpiece cooling unit 14 has fans 24 on the upper side and the lower side of the conveyor 15, and reflow heating is performed by the cold air from the fan 24. The subsequent workpiece W is cooled.
[0015]
The ambient temperatures of the preheat heating unit 12 and the reflow heating unit 13 are detected by the temperature sensors 18 and 23, respectively, and energization of the heaters 16 and 21 is performed so that these detected temperatures become set target temperatures. Each amount is controlled.
[0016]
For example, as shown in FIG. 1, in the ambient temperature control system of the reflow heating unit 13, each temperature sensor 23 that detects the ambient temperature is connected to a controller 25 as a control unit, and the controller 25 includes each temperature sensor 23. The energization amount to each heater 21 is controlled so that the detected temperature according to accords with the target set temperature.
[0017]
As shown in FIG. 1, a circulation system 26 is provided outside the furnace body 11 having the reflow heating section 13, after a high temperature atmosphere is taken out from the reflow heating section 13 and then returned to the furnace body 11.
[0018]
In the circulation system 26, cooling means 28 for cooling the reflow high-temperature atmosphere is interposed in a plurality of pipe lines 27 drawn from the upper part of the furnace body 11.
[0019]
In the cooling means 28, a plurality of circulating air inlets 33 opened in the condenser body 32 of the cooling condenser 31 are connected to the pipe line 27, respectively, and the cooling water is supplied into the condenser body 32 of the cooling condenser 31. The cooling coil 34 for liquefying the vaporized flux is disposed, and the flow rate adjustment for adjusting the flow rate of the cooling water in accordance with the electric signal in the pipe 35 for supplying the cooling water to the cooling coil 34 of the cooling capacitor 31. A motorized valve 36 is provided as a valve.
[0020]
Furthermore, pipes 38 are connected to a plurality of circulating air outlets 37 opened in the condenser main body 32 of the cooling condenser 31, and the cooling condenser 31 is passed through a Т-shaped pipe joint portion 39 connecting these pipes 38. Then, a temperature sensor 41 for detecting the temperature of the circulating air is connected, and this temperature sensor 41 is connected to a temperature indicating controller 42 as temperature adjusting means.
[0021]
The control line 43 drawn from the temperature indicating controller 42 is connected to the operating portion 36a of the motor operated valve 36, and the temperature of the circulating air detected by the temperature sensor 41 is set by the temperature indicating controller 42. The function of adjusting the flow rate of the cooling water throttled by the motor-operated valve 36 is provided.
[0022]
The controller 25 opens the motor-operated valve 36 of the cooling means 28 to the maximum (100%) when the lowering range of the ambient temperature of the reflow heating unit 13 is equal to or higher than a desired temperature (for example, 10 ° C.) that can be arbitrarily set. Thus, the control means 44 is a control means for starting the operation for increasing the cooling capacity of the cooling condenser 31 compared with the normal operation, that is, the cooling operation.
[0023]
That is, the controller 25 automatically starts the cooling operation at the time of a setting change that lowers the set value of the set temperature of the reflow heating unit 13 by a desired temperature (for example, 10 ° C.) that can be arbitrarily determined, while the reflow heating unit 13 Is provided with a function of automatically stopping the cooling operation when an error between the detected temperature and the set temperature falls within a predetermined temperature (for example, 5 ° C.) that can be arbitrarily set.
[0024]
A liquefied flux recovery port 45 is provided at the bottom of the condenser main body 32 of the cooling capacitor 31, and the liquefied flux condensed from the circulating air cooled by the cooling capacitor 31 is connected to the liquefied flux recovery port 45 via a conduit 46. A flux recovery tank 47 is connected as a flux recovery means for recovery.
[0025]
Further, the circulation system 26 has a dedicated blower unit 51 for circulation, and the Т-shaped pipe joint portion 39 is connected to the blower unit 51. This blower unit 51 is an integrated unit of a filter 52 that removes flux mist and dust that has not been liquefied in the circulating air, and a blower 53 that is provided on the downstream side of the filter 52 as a blowing means. is there.
[0026]
The blower outlet 54 of the blower 53 is connected to the lower part of the furnace body 11 through a pipe 55.
[0027]
Next, the operation of the embodiment shown in FIG. 1 will be described.
[0028]
The basic operation is to extract the high temperature atmosphere from the reflow heating unit 13 of the furnace body 11 by the suction force of the blower 53 and to condense the vapor component vaporized by passing through the cooling capacitor 31, and the liquefied flux is used for flux recovery. The circulating air collected in the tank 47 and flux-removed is returned to the reflow heating unit 13 through the filter 52 and the blower 53.
[0029]
(Cooling operation)
In response to a change in the workpiece W, when a setting change is made to lower the set temperature of the reflow heating unit 13 by 10 ° C. (optional setting) or more by an input operation to the controller 25, a signal from the controller 25 is received. The temperature indicating controller 42 automatically starts the cooling operation.
[0030]
In this cooling operation, in order to shorten the cooling time, the motor-operated valve 36 for controlling the amount of cooling water is set to 100% output, that is, fully opened to increase the cooling efficiency.
[0031]
Then, the cooling operation is automatically stopped when the error between the detected temperature of the reflow heating unit 13 and the set temperature in the controller 25 is within 5 ° C. (can be arbitrarily set).
[0032]
Thus, in the cooling operation, the temperature in the reflow heating unit 13 is automatically lowered in a short time.
[0033]
During this cooling operation, the flux recovery capability of the cooling means 28 is maximized.
[0034]
(During normal operation)
During normal operation other than during cooling operation, the temperature of the circulating air that has passed through the cooling condenser 31 is detected by the temperature sensor 41, and the temperature indication is set so that this detected temperature is equal to the temperature set by the temperature indication controller 42. The controller 42 controls the circulating amount of the cooling water by using the electric valve 36.
[0035]
As a result, the cooling capacity of the cooling condenser 31 does not increase as much as during the cooling operation, but the temperature of the circulating air can be lowered to a temperature sufficient to condense and collect the flux.
[0036]
With such a control system, it corresponds to the fact that the condensation temperature, that is, the liquefaction temperature, of the flux gas in the circulating air differs depending on the soldering material (solder paste) used.
[0037]
Next, the effect of the embodiment shown in FIG. 1 will be described.
[0038]
Since the cooling means 28 for cooling the high-temperature atmosphere in the reflow heating unit 13 is interposed in the circulation system 26 provided outside the furnace body 11, the ambient temperature in the reflow heating unit 13 set according to the workpiece W is set. It can be lowered significantly in a short time.
[0039]
At this time, since the high temperature atmosphere is cooled by the cooling means 28 of the circulation system 26 provided outside the furnace body 11, it is possible to prevent the flux in the atmosphere from being liquefied and adhering to the furnace body 11 during this cooling.
[0040]
When the reduction range of the atmospheric temperature is large, the controller 25 allows the cooling function of the cooling means 28 to function to the maximum extent, so that the high temperature atmospheric temperature in the reflow heating unit 13 can be automatically reduced in a short time.
[0041]
The flux recovery tank 47 can recover the flux contained in the high-temperature atmosphere in the furnace body 11 and prevent the liquefied flux from adhering to the inner wall of the furnace body 11.
[0042]
In the atmospheric temperature lowering control and flux recovery control in the furnace body 11, the temperature of the circulating air after passing through the cooling capacitor 31 is detected by the temperature sensor 41, and the temperature set in the temperature indicating controller 42 is set as a target value. This temperature indicating controller 42 adjusts the motor-operated valve 36 so that the temperature detected by the temperature sensor 41 matches the set temperature, and controls the circulation amount of the cooling water, thereby feedback controlling the temperature of the circulating air with high accuracy. It is possible to cope with differences in flux gas liquefaction temperature depending on the soldering material used.
[0043]
Since the circulating air from which the flux mist and the like have been removed by the filter 52 is sucked into the blower 53, the possibility of flux adhering to the blower 53 can be prevented.
[0044]
Next, the second embodiment shown in FIG. 3 will be described. In addition, the same code | symbol is attached | subjected to the part similar to 1st Embodiment shown by FIG. 1, and the description is abbreviate | omitted.
[0045]
A heating unit 61 is disposed downstream of the cooling unit 28 in the circulation system 26.
[0046]
That is, the heating unit 61 is connected to the air outlets 54 of the blower 53 via the pipes 55, respectively, and the inlet 63 of the heating tank 62 is connected to the inside of the heating tank 62 to heat the circulating air. Further, a temperature sensor 66 is provided in the Т-shaped pipe joint portion 65 connected to the heating tank 62, and this temperature sensor 66 is connected to a temperature indicating controller 67 for controlling the heater 64. Has been.
[0047]
The temperature indicating controller 67 controls the energization amount of the heater 64 so that the temperature of the circulating air detected by the temperature sensor 66 becomes equal to the temperature set by the temperature indicating controller 67. Further, the Т-shaped pipe joint portion 65 is connected to the lower portion of the furnace body 11 by a pipe line 55.
[0048]
Then, when the high-temperature atmosphere is extracted from the reflow heating unit 13 by the suction force of the blower 53 and passes through the cooling condenser 31, the flux component in the circulating wind is condensed and collected, and the circulating wind passed through the filter 52 and the blower 53. Is raised in the heating tank 62 of the heating unit 61 and then returned to the reflow heating unit 13.
[0049]
At that time, when a setting change is made to lower the set temperature of the reflow heating unit 13 by 10 ° C. (optional setting) or more by an input operation to the controller 25, the temperature indicating controller 42 is output by a signal output from the controller 25. However, the cooling operation of the cooling means 28 is automatically started, and the motor control valve 36 for controlling the cooling water amount is controlled to be fully opened.
[0050]
During this cooling operation, the heating unit 61 does not function, and the circulating air that has passed through the filter 52 and the blower 53 is returned to the reflow heating unit 13 without being heated in the heating tank 62.
[0051]
On the other hand, when the error between the detected temperature of the reflow heating unit 13 and the set temperature falls within a predetermined temperature (for example, 5 ° C.) that can be arbitrarily set, the controller 25 automatically stops the cooling operation, The motor control valve 36 for controlling the cooling water amount is controlled to be throttled through the instruction controller 42.
[0052]
During normal operation, the controller 25 controls the motor control valve 36 for controlling the amount of cooling water through the temperature indicating controller 42 of the cooling means 28 and transmits a control signal to the temperature indicating controller 67 of the heating unit 61. Then, the temperature of the circulating air lowered for flux recovery is returned to the reflow heating unit 13 after returning to the set temperature of the reflow heating unit 13.
[0053]
As described above, after returning the circulating air whose temperature has decreased after the flux recovery process to the reflow heating unit 13 (high temperature part) of the furnace body 11, the circulating air is heated by the heating unit 61, and the inside of the reflow heating unit 13 is heated. By raising the temperature to the ambient temperature, the temperature change in the reflow heating unit 13 can be reduced.
[0054]
【The invention's effect】
According to the first aspect of the present invention, since the cooling means for cooling the high-temperature atmosphere in the reflow heating unit is interposed in the circulation system provided outside the furnace body, the ambient temperature in the reflow heating unit is set according to the work. It can be lowered in a short time, and at this time, the high temperature atmosphere is cooled by a circulation system provided outside the furnace body, so that the flux in the atmosphere can be prevented from liquefying and adhering to the furnace body during this cooling. it can.
[0055]
According to the second aspect of the present invention, the control means increases the cooling capacity of the cooling means more than usual when the decrease range of the atmospheric temperature is large. Therefore, the high temperature atmosphere temperature in the reflow heating section is automatically reduced in a short time. be able to.
[0056]
According to the third aspect of the present invention, the flux recovery means can recover the flux contained in the high temperature atmosphere in the furnace body, and at this time, the high temperature atmosphere is cooled in the circulation system outside the furnace body. Can be prevented from adhering to the furnace.
[0057]
According to the fourth aspect of the invention, in the atmospheric temperature lowering control and the flux recovery control in the furnace body, the temperature of the circulating air after passing through the cooling condenser is detected by the temperature sensor, and the temperature set in the temperature adjusting means is determined. As a target value, this temperature adjustment means feeds back the temperature of the circulating air with high accuracy by adjusting the flow rate adjustment valve so that the detected temperature of the temperature sensor matches the set temperature and controlling the circulating amount of cooling water. It can be controlled and can cope with the difference in the liquefaction temperature of the flux gas depending on the soldering material used.
[0058]
According to the fifth aspect of the present invention, since the circulating air from which the flux mist and the like have been removed by the filter is sucked into the blowing means, it is possible to prevent the flux from adhering to the blowing means.
[0059]
According to the sixth aspect of the present invention, the temperature change in the reflow heating unit is reduced by heating the circulating air returned to the reflow heating unit of the furnace body to the ambient temperature of the reflow heating unit by the heating unit. it can.
[Brief description of the drawings]
FIG. 1 is a circuit diagram showing a first embodiment of a reflow apparatus according to the present invention.
FIG. 2 is a sectional view showing an outline of the reflow apparatus.
FIG. 3 is a circuit diagram showing a second embodiment of the reflow apparatus according to the present invention.
[Explanation of symbols]
W Work 11 Furnace 13 Reflow heating section 25 Controller 26 as control means Circulation system 28 Cooling means 31 Cooling capacitor 36 Electric valve 41 as flow rate adjusting valve Temperature sensor 42 Temperature indicating controller 47 as temperature adjusting means 47 As flux collecting means Flux recovery tank 52 Filter 53 Blower 61 as blowing means Heating unit

Claims (6)

A furnace body having a reflow heating section for reflow heating the workpiece;
A circulation system that is provided outside the furnace body and returns to the furnace body after taking out the high temperature atmosphere from the reflow heating unit, and
A reflow apparatus comprising cooling means interposed in the circulation system for cooling a high temperature atmosphere. 2. The reflow apparatus according to claim 1, further comprising a control unit that increases the cooling capacity of the cooling unit when the atmospheric temperature is not lower than a desired temperature that can be arbitrarily set. 3. A reflow apparatus according to claim 1, further comprising a flux collecting means for collecting the flux condensed from the circulating air cooled by the cooling means. The cooling means is
A cooling condenser that receives the supply of cooling water and liquefies the vaporized flux,
A flow rate adjusting valve for adjusting the flow rate of cooling water supplied to the cooling condenser;
A temperature sensor for detecting the temperature of the circulating air after passing through the cooling condenser;
4. A temperature adjusting means for adjusting the flow rate of the cooling water of the flow rate adjusting valve so as to control the temperature of the circulating air detected by the temperature sensor to a set temperature. The reflow apparatus in any one of. The circulatory system is
A filter that removes the flux in the circulating wind;
The reflow device according to any one of claims 1 to 4, further comprising a blowing unit provided on a downstream side of the filter. The reflow apparatus according to any one of claims 1 to 5, wherein the circulation system includes a heating unit disposed downstream of the cooling means.

Images