WO2005000513A1

WO2005000513A1 - Reflow device

Info

Publication number: WO2005000513A1
Application number: PCT/JP2004/008876
Authority: WO
Inventors: Fumihiro Yamashita; Kiyoshi Dozono
Original assignee: Kabushiki Kaisha Tamura Seisakusho; Kabushiki Kaisha Tamura Fa System
Priority date: 2003-06-27
Filing date: 2004-06-24
Publication date: 2005-01-06
Also published as: JP2005014074A

Abstract

A reflow device capable of reducing in a short time the temperature in a reflow heating portion of a furnace body and preventing adhesion of a flux gas in the reflow heating portion. A circulation system (26) is provided outside a furnace body (11) for heating by reflow a work piece (W) in a reflow heating portion (13), where the circulation system (26) takes out a high-temperature atmosphere to the outside and then returning it to the furnace body (11). Cooling means (28) for cooling the high-temperature atmosphere is provided in the circulation system (26). The cooling means (28) has a cooling condenser (31) for liquefying vaporized-state flux by fed cooling water. A flow rate of the cooling water fed to the cooling condenser (31) is regulated by an electrically operated valve (36) operated according to an electric signal. The temperature of circulation air after it passed the cooling condenser (31) is detected by a temperature sensor (41). A temperature indicator/adjuster (42) that received the detected circulation air temperature from the temperature sensor (41) adjusts a flow rate of the cooling water flowing through the electrically operated valve (36) so that the detected temperature is adjusted to a temperature set by the temperature indicator/adjuster (42).

Description

Specification

Reflow equipment

Technical field

The present invention relates to a reflow device for cooling a high-temperature atmosphere.

Background art

[0002] 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 a work temperature profile at the time of reflow heating can be more finely controlled. Reference 1).

Patent Document 1: JP-A-2000-188466 (page 1, FIG. 1)

Disclosure of the invention

Problems to be solved by the invention

[0003] In the case where the cooling means is provided in the reflow heating section of such a furnace body, there is a possibility that the flux condenses and solidifies in the furnace body and adheres to the furnace body or the like.

[0004] The present invention has been made in view of the above points, and a reflow apparatus capable of reducing the temperature in a reflow heating section of a furnace body in a short time and preventing flux gas from adhering in the reflow heating section. The purpose is to provide.

Means for solving the problem

[0005] The invention described in claim 1 provides a furnace body having a reflow heating section for reflow heating a work, and a furnace body provided outside the furnace body and after taking out a high-temperature atmosphere from the reflow heating section to the outside. And a cooling means interposed in the circulation system for cooling the high-temperature atmosphere, wherein the high-temperature atmosphere in the reflow heating section is provided in the circulation system provided outside the furnace body. Because the cooling means for cooling the reflow heating unit is interposed, the ambient temperature in the reflow heating unit can be reduced in a short time according to the peak, and at this time, the atmosphere temperature is provided outside the furnace body. Since the high-temperature atmosphere is cooled by the circulation system, it is possible to prevent the possibility that the flux in the atmosphere is liquefied and adheres to the furnace during the cooling.

[0006] The invention described in claim 2 is a reflow apparatus according to claim 1, wherein the reflow apparatus has an atmosphere temperature. Control means for making the cooling capacity of the cooling means larger than usual when the decrease in the temperature is equal to or higher than a desired temperature which can be arbitrarily set. However, since the cooling capacity of the cooling means is made larger than usual, the high-temperature atmosphere temperature in the reflow heating section can be automatically lowered in a short time.

[0007] The invention described in claim 3 is the reflow apparatus according to claim 1 or 2, further comprising a flux recovery means for recovering the flux condensed from the circulating air cooled by the cooling means. The flux contained in the high-temperature atmosphere in the furnace can be recovered by the above-mentioned flux recovery means. At that time, the high-temperature atmosphere is cooled by a circulation system outside the furnace, so that the liquefied flux is removed from the furnace. Can be prevented.

[0008] The invention described in claim 4 is a reflow device according to any one of claims 1 to 3, wherein the cooling means is provided with a cooling capacitor that receives supply of cooling water and liquefies a vaporized flux. A flow rate adjusting valve for adjusting a flow rate of the cooling water supplied to the cooling condenser; a temperature sensor for detecting a temperature of the circulating wind after passing through the cooling condenser; and a circulating wind detected by the temperature sensor. Temperature control means for controlling the flow rate of the cooling water of the flow rate control valve so as to control the temperature to the set temperature. The temperature of the circulating air after passing through the cooling capacitor is detected by the temperature sensor, and the temperature set by the temperature control unit is set as a target value. By adjusting the flow control valve so that the temperature matches the set temperature and controlling the amount of cooling water circulation, the temperature of the circulating air can be feedback controlled with high accuracy, and the flux gas liquefaction by the soldering material used Compatible with temperature differences.

[0009] The invention described in claim 5 provides a filter for removing the flux in the circulating system power circulating wind in the reflow device according to any one of claims 1 to 4, and a filter provided downstream of the filter. Since the circulating air from which the flux mist or the like has been removed by the filter is sucked into the blowing means, it is possible to prevent the possibility that the flux adheres to the blowing means.

[0010] The invention described in claim 6 is provided with a heating unit disposed downstream of the circulating system power cooling means in the reflow device according to claims 1 to 5, and includes a heating unit. By heating the circulating air returned to the reflow heating section of the furnace body by the heat and raising the temperature to the ambient temperature of the reflow heating section, the temperature change in the reflow heating section can be reduced.

The invention's effect

According to the first aspect of the invention, since the cooling means for cooling the high-temperature atmosphere in the reflow heating section is interposed in the circulation system provided outside the furnace body, the reflow heating is performed according to the workpiece. The temperature of the atmosphere inside the furnace can be reduced in a short time, and at this time, the high-temperature atmosphere is cooled by the circulation system provided outside the furnace body. The risk of adhering to the body can be prevented.

[0012] According to the second aspect of the present invention, when the decrease in the ambient temperature is large, the control unit increases the cooling capacity of the cooling unit more than usual, so that the high-temperature ambient temperature in the reflow heating unit can be reduced in a short time. Can be lowered automatically.

[0013] According to the invention as set forth in claim 3, the flux contained in the high-temperature atmosphere in the furnace can be recovered by the flux recovery means, and at this time, the high-temperature atmosphere is cooled by the circulation system outside the furnace. The liquefied flux can be prevented from adhering to the inside of the furnace.

[0014] According to the invention described in claim 4, the temperature of the circulating air after passing through the cooling condenser is detected by the temperature sensor, and the temperature of the circulating air after passing through the cooling condenser is detected by the temperature sensor. With the temperature set in the adjusting means as a target value, the temperature adjusting means controls the circulation amount of the cooling water by adjusting the flow control valve so that the detected temperature of the temperature sensor matches the set temperature. The temperature of the circulating air can be feedback controlled with high precision, and the difference in the flux gas liquefaction temperature depending on the soldering material used can be handled.

According to the invention described in claim 5, the circulating air from which the flux mist or the like has been removed by the filter is sucked into the blowing means, so that the possibility that the flux adheres to the blowing means can be prevented.

[0016] According to the invention described in claim 6, the heating unit heats the circulating air returned to the reflow heating section of the furnace body and raises the temperature to the ambient temperature of the reflow heating section, so that the inside of the reflow heating section is heated. Temperature change can be reduced.

Brief Description of Drawings

FIG. 1 is a circuit diagram showing a first embodiment of a reflow device according to the present invention. Garden 2] FIG. 2 is a sectional view showing an outline of the reflow device.

Garden 3] 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 as control means

26 Circulatory system

28 Cooling means

31 Cooling condenser

36 Motorized valve as flow control valve

41 Temperature sensor

42 Temperature indicating controller as temperature adjusting means

47 Flux recovery tank as flux recovery means

52 Huinoleta

53 Blower as blowing means

61 heating unit

BEST MODE FOR CARRYING OUT 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.

First, a first embodiment shown in FIGS. 1 and 2 will be described. As shown in FIG. 2, a reflow device is provided inside a furnace body 11 for preheating a workpiece W. There is provided a pre-heat heating unit 12, a reflow heating unit 13 for reflow heating the work W, and a work cooling unit 14 for cooling the work W. A conveyor 15 that engages and transports the work W with the endless chains on both sides is provided so as to penetrate the preheat heating section 12, the reflow heating section 13 and the work cooling section 14.

The preheat heating unit 12 has a heater 16, a fan 17, and a temperature sensor 18 on the upper and lower sides of the conveyor 15, and radiates heat from the heater 16 and generates relatively low-temperature hot air by the fan 17. The workpiece W is preheated by the heated atmosphere, and the reflow heating section 13 has a heater 21, a fan 22, and a temperature sensor 23 on the upper side and the lower side of the conveyor 15 to be heated to a higher temperature than the preheat heating section 12. The work W is mainly heated by the radiant heat from 21 and the high-temperature atmosphere which has been turned into a relatively high-temperature hot air by the fan 22. Further, the work cooling unit 14 has a fan 24 on the upper side and the lower side of the conveyor 15, and this fan The cool air from 24 cools the peak W after the reflow heating.

[0022] The ambient temperatures of the preheat heating section 12 and the reflow heating section 13 are detected by the temperature sensors 18 and 23, respectively, and the heaters 16 and 16 are set so that the detected temperatures become the set target temperatures. The amount of current to the power supply 21 is controlled.

For example, as shown in FIG. 1, in the atmosphere temperature control system of the reflow heating unit 13, each temperature sensor 23 for detecting the atmosphere temperature is connected to a controller 25 as a control means. The amount of power to each heater 21 is controlled so that the temperature detected by the temperature sensor 23 matches the target set temperature.

As shown in FIG. 1, a circulation system 26 is provided outside the furnace body 11 having the reflow heating section 13 to take out a high-temperature atmosphere from the reflow heating section 13 and then return it to the furnace body 11. It has been done.

The circulation system 26 has a plurality of pipes 27 drawn from the upper part of the furnace body 11 and cooling means 28 for cooling the high-temperature reflow atmosphere interposed therebetween.

In the cooling means 28, a plurality of circulating air inlets 33 opened to the condenser body 32 of the cooling condenser 31 are connected to the pipe 27, respectively, and the cooling water is supplied into the condenser body 32 of the cooling condenser 31. A cooling coil 34 for liquefying the vaporized flux by receiving the cooling water is provided, and a cooling water flow is supplied to the cooling coil 34 of the cooling condenser 31 in a pipe line 35 according to an electric signal. An electric valve 36 is provided as a flow regulating valve for adjusting.

[0027] Further, pipes 38 are respectively connected to a plurality of circulating air outlets 37 opened in the condenser main body 32 of the cooling condenser 31, and cooling is provided to a T-shaped pipe joint section 39 connecting these pipes 38. A temperature sensor 41 for detecting the temperature of the circulating air after passing through the condenser 31 is connected, and the temperature sensor 41 is connected to a temperature indicating controller 42 as temperature adjusting means. [0028] A 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 indicated by the temperature indicating controller 42. A function is provided for adjusting the flow rate of the cooling water throttled by the electric valve 36 so as to control the temperature to the indicated and set temperature.

[0029] The controller 25 sets the electric valve 36 of the cooling means 28 to the maximum (100 %) Is a control means for opening the valve to start the cooling operation in which the cooling capacity of the cooling condenser 31 is increased from that in the normal operation, that is, the cooling operation is started.The control line 44 of the controller 25 is connected to the temperature indicating controller 42. It is connected to the.

[0030] That is, the controller 25 automatically starts the cooling operation when the set value of the set temperature of the reflow heating unit 13 is changed to a desired temperature (for example, 10 ° C) which can be arbitrarily set, and the cooling operation is started. In addition, a function is provided for automatically stopping the cooling operation when the error between the detected temperature of the reflow heating unit 13 and the set temperature falls within a arbitrarily settable predetermined temperature (for example, 5 ° C.).

A liquefied flux recovery port 45 is provided at the bottom of the condenser body 32 of the cooling condenser 31, and the liquefied flux recovery port 45 is condensed from the circulating air cooled by the cooling condenser 31 via a pipe 46. A flux recovery tank 47 is connected as a flux recovery means for recovering the liquefied flux.

Further, the circulation system 26 has a dedicated blower unit 51 for circulation, and the T-shaped fitting 39 is connected to the blower unit 51. The blower unit 51 has a filter 52 for removing flux mist and dust that has not been liquefied in the circulating air, and a blower 53 provided as a blower provided downstream of the filter 52, which is integrated with a force S. It is.

The blow-out port 54 of the blower 53 is connected to a lower part of the furnace body 11 via a pipe 55.

Next, the operation of the embodiment shown in FIG. 1 will be described.

The basic operation is as follows. The suction force of the blower 53 extracts the high-temperature atmosphere from the reflow heating section 13 of the furnace body 11 and passes through the cooling condenser 31 to condense the vaporized flux components, and the liquefied flux The circulating air from which the flux has been collected in the flux recovery tank 47 and whose flux has been removed is returned to the reflow heating section 13 through the filter 52 and the blower 53. (Cooling operation)

If the setting temperature of the reflow heating section 13 is changed by more than 10 ° C (can be set arbitrarily) by input operation to the controller 25 due to the change of the workpiece W, the signal from the controller 25 is sent. The received temperature indicating controller 42 automatically starts cooling operation.

[0037] In this cooling operation, in order to shorten the cooling time, the motor-operated valve 36 for controlling the cooling water amount is set to the output of 100%, that is, the fully opened state, and the cooling efficiency is increased.

Then, an error between the temperature detected by the reflow heating unit 13 and the temperature set by the controller 25 is

When the temperature falls below 5 ° C (can be set arbitrarily), the cooling operation is automatically stopped.

As described above, in the cooling operation, the temperature in the reflow heating unit 13 is automatically decreased in a short time.

[0040] During this cooling operation, the flux collecting ability of the cooling means 28 is maximized.

[0041] (during normal operation)

During normal operation other than the cooling operation, the temperature of the circulating air passing through the cooling condenser 31 is detected by the temperature sensor 41, and the temperature indication is set so that the detected temperature becomes equal to the temperature set by the temperature indication controller 42. The controller 42 controls the amount of cooling water circulated by the motor-operated valve 36.

[0042] As a result, the cooling capacity of the cooling condenser 31 does not increase during the cooling operation, but the temperature of the circulating air can be reduced to a temperature sufficient to condense and recover the flux.

With such a control system, the condensing temperature of the flux gas in the circulating air, that is, the liquefaction temperature is different depending on the soldering material (solder paste) used.

Next, effects of the embodiment shown in FIG. 1 will be described.

[0045] 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 reflow heating unit 13 in the reflow heating unit 13 set according to the work W is provided. The ambient temperature can be significantly reduced in a short time.

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, the flux in the atmosphere liquefies during this cooling and is likely to adhere to the inside of the furnace body 11. Can be prevented.

[0047] When the decrease in the ambient temperature is large, the controller 25 allows the cooling function of the cooling means 28 to function to the utmost, so that the high-temperature ambient temperature in the reflow heating unit 13 can be automatically reduced in a short time. .

[0048] The flux recovery tank 47 can recover the flux contained in the high-temperature atmosphere in the furnace body 11, and can prevent the liquefied flux from adhering to the inner wall of the furnace body 11.

In the atmosphere temperature lowering control and the 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 detected. As a target value, the temperature indicating controller 42 controls the circulation amount of the cooling water by adjusting the electric valve 36 so that the temperature detected by the temperature sensor 41 matches the set temperature, thereby reducing the temperature of the circulating air. It can perform feedback control with high accuracy and can respond to differences in the flux gas liquefaction temperature depending on the soldering material used.

[0050] Since the circulating air from which the flux mist or the like has been removed by the filter 52 is sucked into the blower 53, the possibility that the flux adheres to the blower 53 can be prevented.

Next, a second embodiment shown in FIG. 3 will be described. The same parts as those in the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.

[0052] A heating unit 61 is provided downstream of the cooling means 28 of the circulation system 26.

That is, in the heating unit 61, an inlet 63 of a heating tank 62 is connected to each outlet 54 of the blower 53 via each pipe 55, and a circulating wind is provided inside the heating tank 62. A heater 64 for heating the heater 64 is provided. Further, a temperature sensor 66 is provided at a T-shaped fitting section 65 connected to the heating tank 62, and the temperature sensor 66 provides a temperature instruction for controlling the heater 64. Connected to controller 67.

The temperature indicating controller 67 controls the amount of electricity supplied to the heater 64 such that the temperature of the circulating air detected by the temperature sensor 66 becomes equal to the temperature indicated and set by the temperature indicating controller 67. I do. Further, the T-shaped pipe joint portion 65 is connected to a lower portion of the furnace body 11 by a pipe line 55.

[0055] Then, the high-temperature atmosphere is extracted from the reflow heating unit 13 by the suction force of the blower 53, and when passing through the cooling condenser 31, the flux components in the circulating air are condensed and collected. The circulating air passing through 53 is passed through the heating tank 62 of the heating unit 61. After the temperature is raised, the temperature is returned to the reflow heating unit 13.

At that time, when a setting change is made by input operation to the controller 25 to lower the set temperature of the reflow heating unit 13 by 10 ° C. or more (optionally settable), a signal output from the controller 25 The temperature indicating controller 42 automatically starts the cooling operation of the cooling means 28 and controls the motor-operated valve 36 for controlling the amount of cooling water to a fully open state.

During the 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 that does not need to heat the inside of the heating tank 62.

[0058] On the other hand, when the error between the detected temperature of the reflow heating unit 13 and the set temperature falls within the arbitrarily settable temperature (for example, 5 ° C), the controller 25 automatically starts the cooling operation. Is stopped, and the electric valve 36 for controlling the amount of cooling water is throttled through the temperature indicating controller 42.

During normal operation, the controller 25 throttle-controls the electric valve 36 for controlling the amount of cooling water via the temperature indicating controller 42 of the cooling means 28 and controls the temperature indicating controller 67 of the heating unit 61 by a control signal. Is sent to return the temperature of the circulating air lowered for the purpose of flux recovery to the set temperature of the reflow heating unit 13 and then return to the reflow heating unit 13.

[0060] As described above, after returning the circulating air having the lowered temperature to the reflow heating section 13 (high temperature section) of the furnace body 11, the circulating air is heated by the heating unit 61, and the reflow heating section is heated. By raising the temperature to the ambient temperature in the chamber 13, it is possible to reduce the temperature change in the reflow heating section 13.

Industrial applicability

The present invention can control the work temperature profile at the time of reflow heating, and can be applied to reflow using lead-free solder that requires strict temperature control.

Claims

The scope of the claims

[1] a furnace body having a reflow heating unit for reflow heating the work,

A circulating system provided outside the furnace body, for taking out the high-temperature atmosphere from the reflow heating section to the outside, and then returning to the furnace body;

Cooling means interposed in the circulation system for cooling the high-temperature atmosphere;

A reflow apparatus comprising:

[2] Control means for increasing the cooling capacity of the cooling means above normal when the decrease in the ambient temperature is equal to or higher than a desired temperature which can be set arbitrarily

The reflow apparatus according to claim 1, further comprising:

[3] Flux collecting means for collecting the flux condensed from the circulating wind cooled by the cooling means

The reflow apparatus according to claim 1 or 2, further comprising:

[4] The cooling means

A cooling condenser that receives the supply of cooling water to liquefy the vaporized flux, a flow regulating valve that regulates a flow rate of the cooling water supplied to the cooling condenser, and a temperature of the circulating air that has passed through the cooling condenser. A temperature sensor for detecting, and a temperature adjusting means for adjusting a flow rate of the cooling water of the flow rate adjusting valve so as to control a temperature of the circulating air detected by the temperature sensor to a set temperature.

The reflow apparatus according to any one of claims 1 to 3, further comprising:

[5] The circulatory system

A filter for removing the flux in the circulating wind,

A blower provided downstream of the filter;

The reflow apparatus according to any one of claims 1 to 4, comprising:

[6] The circulation system has a heating unit arranged downstream of the cooling means.

The reflow apparatus according to any one of claims 1 to 5, wherein: