JP2001300358A - Flux applicator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control the temperature of a sprayed flux to keep a good soldering quality in applying a flux sprayed from a spray nozzle of a flux applicator to a printed circuit board (a work to be coated with flux) even though more VOC-free flux such as a water-soluble flux is used to protect the ozone layer. SOLUTION: A temperature controller 34 is provided to keep the flux 4 in a flux feed tank 22 at a specified temperature, and the flux is circulated between the feed tank and a spray nozzle 3. Besides, the temperature of spraying air 5 is controlled to keep the sprayed flux 4a at a fixed temperature. Further, a heating and drying device 57 is furnished to heat and dry the flux 4 sprayed and applied to the printed circuit board 1 in an early stage.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flux applying apparatus for spraying and applying a flux to a work to be applied with a flux, for example, a printed wiring board on which a large number of electronic components are mounted to form an electronic circuit.

[0002] The printed wiring board to which the flux is applied by the flux applying device is then supplied with a molten solder by a soldering device (for example, a flow type soldering device) and soldered. It is necessary to apply a flux to a printed wiring board uniformly, without unevenness, and stably over time to obtain good and stable soldering quality of the printed wiring board. The applied flux is
It must be sufficiently dried before soldering, and penetration into printed wiring boards must be minimized.

[0003]

2. Description of the Related Art A flux coating apparatus for spraying and applying a flux can apply a flux uniformly and thinly to a printed wiring board, and has excellent controllability of a flux application amount. Etc.

An example of a conventional spray-type flux coating apparatus will be described with reference to FIG.

FIG. 8 is a side sectional view showing a conventional spray type flux coating apparatus. That is, the printed wiring board 1 which is a plate-shaped workpiece to be coated with a flux is held by holding two side ends of the printed wiring board 1 on two parallel conveyors 2 corresponding to the width of the printed wiring board 1 in the direction of arrow A. In FIG. 8, the flux 4 is sprayed from the spray nozzle 3a of the spray nozzle 3 provided below the conveyor 2 in opposition to the flux application surface 1a of the printed wiring board 1, and the spray flux 4a is The configuration is such that the flux is applied to the flux application surface 1a of the printed wiring board 1 and applied. An example of a technique for stably and precisely controlling the spray flow rate of the flux is disclosed in Japanese Patent Application Laid-Open No. 4-59169.

There are various types of spray nozzles 3. In general, a two-fluid nozzle that supplies a flux 4 to be sprayed and air for spraying (spray air) 5 has a higher coating efficiency of the flux 4. And the flux 4 can be well applied to the inside of the through hole of the printed wiring board 1.

The gate air 6 is for opening and closing the needle valve in the spray nozzle 3, and is a means for controlling start and stop of spray. As an example of a spray control technique for preventing clogging of the spray nozzle section 3a, for example, there is a technique disclosed in Japanese Patent Application Laid-Open No. Hei 4-366758.

In this case, the flux 4 is a pipe 19
The spray air 5 and the gate air 6 are respectively supplied by pipes 18.

Generally, the spray nozzle 3 is connected to the pipe 1
8 and pipe 19 are connected, and flux 4 and air
And a spray nozzle 3a for spraying the flux 4.

On the other hand, the spray flux 4 a that has not been applied to the printed wiring board 1 is sucked in by the exhaust fan 7 together with the air (atmosphere) around the exhaust hood 8, and the filter 4 collects the flux 4. After being collected and removed, the air is exhausted from the exhaust duct 10.

The transport conveyor 2 is constituted by a transport chain (not shown) stretched between a guide sprocket 11 and a driving sprocket 14 driven by a motor 12, and pins (not shown) provided on the transport chain. This is a mechanism for placing and supporting the side end of the printed wiring board 1 on the substrate and transporting it.

Further, the motor 12 is provided with an encoder 13 for detecting the rotation, and its encoding signal (for example, a pulse signal is output at every predetermined rotation angle, and the rotation angle can be obtained by the number of pulses). It is possible to obtain the rotation speed based on the period of the pulse train.), So that the rotation angle, and thus the transfer distance and transfer speed of the transfer conveyor 2 can be detected.

Further, the entry sensor 15 is a sensor for detecting that the printed wiring board 1 has been carried in from the carry-in port 16 and has entered the direction of the spray nozzle 3, ie, the spray position. Specifically, a reflection type optical sensor or the like is used.

The timing at which the flux 4 is sprayed from the spray nozzle 3 is determined by the entry sensor 15.
Detects that but is carried, and in proportion to the conveying distance of the conveyor 2 with reference to the encoded signal S _E output, the flux 4 when the front end of the printed wiring board 1 has reached the position of the spray nozzle 3 Spraying is started, and when the rear end of the printed wiring board 1 reaches the position of the spray nozzle 3, the spraying of the flux 4 is controlled to be stopped. Since such a spray control technique is well known, its means are omitted and not shown.

The swing device 70 is means for causing the spray nozzle 3 to perform a swing operation.
The swing device 70 is fixed to a slider 71. That is, the flux 4 is sprayed and applied while the spray nozzle 3 is swung in a direction perpendicular to the transport direction A of the printed wiring board 1 (a direction perpendicular to the paper surface of FIG. 8, that is, a width direction of the printed wiring board 1). Means. Thereby, the amount of the flux 4 applied to each part of the printed wiring board 1 can be made extremely uniform. Examples of this coating technique include, for example, techniques disclosed in JP-A-4-59170 and JP-A-4-59171.

The viscosity of the flux 4 changes depending on its temperature, and generally, the viscosity increases as the temperature decreases. In addition, VOC (vol.) Such as water-soluble flux, which is increasingly used for the purpose of protecting the ozone layer, is used.
Atile organic compounds (volatile organic compound) free flux has a higher surface tension than a flux containing VOC, and the surface tension further increases with a decrease in temperature.

These changes in viscosity and surface tension affect the spray state of the flux 4 from the spray nozzle 3. For example, the amount of the flux 4 applied to the printed wiring board 1 (flux application amount) changes due to a change in the spray flow rate or the spray particle diameter, or the applied state of the flux 4 becomes uneven and uneven. It becomes. And that causes deterioration of the soldering quality.

Therefore, the spray type flux coating apparatus is not an example of a flux type coating apparatus so that the physical properties of the flux 4 do not change when the flux 4 is coated.
As described in the publication, there is a technique in which a heat exchange device is provided in a tank body for accommodating the flux and the temperature of the flux in the tank is kept constant. Further, as an example of a spray-type flux coating apparatus, there is a technique for indirectly heating a flux container to make the flux temperature constant, as described in Japanese Patent Application Laid-Open No. 10-313169.

[0019]

However, simply heating the flux 4 accommodated in the flux supply container with a heating means such as a heater and keeping the temperature at a constant level is not enough to supply the flux 4 from the flux supply container to the spray nozzle 3. When the flux 4 flows through the flux supply flow path, that is, the pipe 19 for supplying the flux, the temperature of the flux 4 decreases, and the temperature of the flux 4 can be precisely maintained at a predetermined temperature. There is a problem that cannot be done.

Normally, the printed wiring board 1, which is a work to be flux-coated, is intermittently conveyed in accordance with the production tact of the printed wiring board 1, and the flux 4 is sprayed and applied intermittently. The time during which the flux 4 stays in the pipe 19 becomes longer, and the temperature of the flux 4 in the pipe 19 for supplying the flux 4 is more likely to decrease.

Further, the swing type flux applying device illustrated in FIG.
In the flux coating apparatus which sprays the flux 4 while swinging at 0, the pipe 18 for supplying the flux 4 also swings violently in accordance with the swing operation of the spray nozzle 3, so that a heat insulating material is provided on the pipe 18 for supplying the flux 4. And it is particularly difficult to provide a heater for keeping heat.

Further, a VOC-free flux such as a water-soluble flux is harder to dry than a flux containing VOC. Therefore, if the water-soluble flux is not sufficiently dried, bubbles and solder balls are generated at the time of soldering, which causes soldering failure. Also,
If water is allowed to permeate the printed wiring board 1, it becomes more difficult to dry and remove the water, and as described above, bubbles and solder balls are generated at the time of soldering, resulting in poor soldering.

As disclosed in Japanese Patent Application Laid-Open No. 4-59169, as a technique for controlling the spray flow rate of the flux 4 stably and precisely, pressure is applied to the flux 4 housed in a flux supply container. There is a technique for supplying the flux 4 to the spray nozzle 3.

By the way, when the flux 4 in the flux supply container is heated to a predetermined temperature by heating by the heating means, the flux 4 in the flux supply container is added to the flux 4 after the flux 4 is completely empty. When the supplied pressure is released and a large amount of flux is newly supplied to this flux supply container in a short time, in addition to the replenishment work time performed by the operator, the large amount of flux newly supplied to the flux supply container It takes a long time to raise the temperature of this to a predetermined temperature.

Therefore, in order to maintain the uniform and stable application of the flux 4 to the printed wiring board 1 and to maintain the stable and high quality soldering, the temperature of the newly supplied flux 4 is predetermined. During the period until the temperature rises to a predetermined temperature, it is necessary to temporarily stop the application of the flux to the printed wiring board 1, that is, to stop the production. However, this greatly reduces the productivity of soldering production of the printed wiring board 1 performed in flux application and soldering.

An object of the present invention is to realize a flux coating apparatus which maintains good and stable soldering quality of the printed wiring board 1 and does not reduce productivity. More specifically, the temperature of the sprayed flux 4 is constantly maintained without interrupting the application of the flux 4, and the flux 4 applied to the printed wiring board 1 does not penetrate into the printed wiring board 1. It is an object of the present invention to realize a flux coating device that can be dried immediately.

[0027]

SUMMARY OF THE INVENTION A flux coating apparatus of the present invention sprays and applies a flux to a flux application work such as a printed wiring board to set and maintain the temperature of a flux to be applied stably and with high accuracy. In addition, it is characterized in that it is configured to be able to perform the flux application operation continuously without interruption, and that it is configured to be able to dry VOC-free flux such as water-soluble flux at an early stage. (1) In a flux coating apparatus for spraying a flux accommodated in a flux supply container from a spray nozzle and applying the flux to a workpiece to be subjected to flux application, a flux flow path for circulating the flux between the flux supply container and the spray nozzle; It is configured to include a pump.

Thus, even if the flux supply container and the spray nozzle are provided at positions separated from each other, the flux does not stay in the flow path of the flux for a long time to cause a temperature change. That is, by circulating the flux between the spray nozzle and the flow path of the flux and the flux supply container, it is possible to always supply the flux having the same temperature as the temperature of the flux contained in the flux supply container to the spray nozzle. Becomes

Therefore, it is possible to constantly maintain physical properties such as the viscosity and surface tension of the flux supplied to the spray nozzle, and it is possible to spray the flux in a stable manner, and to uniformly spray the flux-coated work. And the flux can be applied stably over time. (2) In a flux coating apparatus for spraying a flux contained in a flux supply container from a spray nozzle and applying the flux to a workpiece to be flux-coated, a temperature control means for maintaining the temperature of the flux contained in the flux supply container at a predetermined temperature. And a flux flow path and a pump for circulating the flux between the flux supply container and the spray nozzle.

Thus, it is possible to supply the flux in the flux supply container whose temperature has been raised or lowered to a predetermined temperature by the temperature control means to the spray nozzle without changing the temperature while maintaining a stable temperature. Becomes That is, even if the flux supply container and the spray nozzle are provided at positions separated from each other, the flux does not stay in the flux supply flow path for a long time, and the temperature does not change.

That is, by circulating the flux between the spray nozzle and the flow path of the flux and the flux supply container, the flux having the same temperature as the flux contained in the flux supply container is always supplied to the spray nozzle. It becomes possible.

Therefore, it is possible to constantly maintain physical properties such as the viscosity and surface tension of the flux supplied to the spray nozzle, and it is possible to spray the flux stably, and to uniformly spray the flux-coated work. And the flux can be applied stably over time. (3) In a flux coating apparatus for spraying a flux accommodated in a flux supply container from a spray nozzle and applying the flux to a workpiece to be flux-coated, the spray nozzle is a two-fluid nozzle using a gas for spraying and is supplied to the spray nozzle. The apparatus is provided with temperature control means for maintaining the temperature of the spray gas to be maintained at a predetermined temperature.

Even if the flux to be sprayed is maintained at a predetermined temperature in advance, if the temperature of the spraying gas is low or high, the atomized mist-like flux has an extremely small heat capacity, so that the temperature immediately drops. The temperature rises,
The temperature changes before coating the flux-coated work, and the physical properties change.

However, by adjusting the temperature of the spraying gas to the temperature of the flux to be sprayed, it is possible to apply the flux to the printed wiring board while maintaining the desired physical properties such as viscosity and surface tension. It becomes possible to stably maintain the particle distribution of the mist-like flux at the time of application and the spread of the application flux wet.

Further, even when the temperature of the flux is lower or higher than the target temperature, heat is exchanged between the spray which has been sprayed into fine particles and has a very small heat capacity, and the spray air. The temperature of the flux may be set to a temperature equivalent to the temperature of the spray air, and the flux may be applied to the work to be flux-coated. Then, similarly, it is possible to stably maintain the particle distribution of the mist-like flux and the wet spread of the coating flux at the time of coating.

Therefore, the flux can be applied and applied stably over time without causing unevenness on the workpiece to be applied with the flux. (4) In a flux coating device which is configured separately from the soldering device and sprays the flux contained in the flux supply container from a spray nozzle and applies the flux to the flux application work, the flux is applied to the flux application work after the flux application. A means for heating and drying the flux is provided.

When a flux is applied to a printed wiring board, it is necessary to dry the solvent component immediately thereafter. This is to prevent the penetration of the solvent into the printed wiring board and to prevent the generation of bubbles and solder balls due to vaporization during soldering. This is because, when air bubbles are generated during soldering, poor soldering such as poor wetting and deformed fillet shape occurs. Further, the solder balls are detached and migrated after the printed wiring board is assembled in the electronic device, which causes a failure.

On the other hand, when a flux application device and a soldering device are combined as a separate device to constitute one soldering system (for example, “Soldering mounting” Author: Kazunori Oki Published: Nikkan Kogyo Shimbun Company
In the case of the configuration shown in Photos 117 of page 117 of the first printing 1st print), the printed wiring board on which the flux is applied by the flux applying device is transported to the preheating means of the soldering device, where heating and drying are performed. By the time you start,
It will take a long time.

In addition, the solvent easily penetrates into the printed wiring board while being conveyed from the flux coating device to the preheating means of the soldering apparatus, and the solvent is sufficiently dried by the preheating means of the soldering apparatus. If not, bubbles will be generated due to evaporation of the solvent during soldering. In particular, these bubbles are easily generated in a VOC-free flux using an aqueous solvent.

However, in the present invention, since the flux coating device is provided with a means for heating and drying the flux applied to the workpiece to be flux-coated, the solvent of the flux applied to the workpiece to be flux-coated immediately after the application of the flux is provided. Of the solvent can be started, and the penetration of the solvent into the printed wiring board can be suppressed.

Therefore, in the soldering device provided at the subsequent stage of the flux coating device, it is possible to perform soldering with good soldering quality. (5) An external flux storage container having a first liquid amount detecting means for storing a flux, detecting the amount of the stored flux and outputting a detection signal, and an outlet for taking out the stored flux. A flux coating apparatus configured separately from the above and configured to spray the flux stored in the flux supply container from the spray nozzle and apply the flux to the workpiece to be flux-coated is configured as follows.

That is, a pressure supply means for applying pressure to the flux stored in the flux supply container, a flow path and a pump for supplying the stored flux from the outlet of the external storage container to the flux supply container are provided. . Then, there is provided a backflow preventing means provided in the flow path and for flowing the flux only in the direction of the flux supply container.

Further, there is provided a second liquid amount detecting means for detecting the amount of the flux in the flux supply container, and further includes a detection signal of the first liquid amount detecting means and a detection signal of the second liquid amount detecting means. From the signal, control means for operating the pump is provided only when the amount of flux in the flux supply container is equal to or less than a predetermined amount and the amount of flux in the external storage container is equal to or more than the predetermined amount.

Thus, the pressurized flux, that is, the pressurized flux supply container can be automatically replenished with flux without opening and reducing the pressure. Therefore, without stopping the flux application work of the flux application device,
Flux can be applied to the work to be applied with flux. Furthermore, the flux application operation can be continued without changing the temperature of the flux in the flux supply container abruptly and without changing the physical properties of the flux.

When the amount of the flux in the external storage container for the flux decreases and the supply of the flux from the external storage container to the flux supply container cannot be performed by the pump, the pump does not operate. Therefore, the external storage container of the empty flux can be replaced with an external storage container in which the flux is sufficiently stored without stopping the flux application operation. In addition, the pressure in the flux supply container does not decrease with this replacement.

More importantly, the configuration is such that the flux is supplied by a pump from a non-pressurized external storage container to the pressurized flux supply container, and the pressure applied to the flux supply container is controlled by the spray nozzle. Therefore, it is necessary to prevent the pressure applied to the flux supply container and, consequently, the pressure applied to the flux from suddenly changing.

When the flux in the external storage container for the flux is emptied and the pump runs idle to suck the atmosphere or the like into the pump, the pressure in the flux supply container at the replenishment destination becomes improper. It fluctuates regularly and the flux spray flow rate from the spray nozzle changes irregularly.

However, in the present invention, there is provided a backflow preventing means for flowing the flux only in the direction of the flux supply container between the pump and the flux supply container.
And since the pump is configured to operate only when the amount of flux in the external storage container of the flux is equal to or more than a predetermined amount, such irregular fluctuation of pressure does not occur, and therefore, from the spray nozzle, The spray flow rate of the flux does not change irregularly. As a result, it is possible to maintain stable spraying of the flux. (6) In the flux applying apparatus of (5), the pump is configured to have a backflow preventing function when the operation is stopped, and also function as the backflow preventing means.

Thus, the same operation as in the above (5) can be obtained without separately providing a backflow prevention means.

[0050]

BEST MODE FOR CARRYING OUT THE INVENTION
It can be implemented in the following embodiment examples. (1) Configuration An example of an embodiment of a flux coating apparatus according to the present invention will be described with reference to FIGS.

FIG. 1 is a view for explaining an embodiment of a flux coating apparatus according to the present invention, and FIG. 2 is a view for explaining another example of a flow path for flux circulation and a structure of temperature control means for spray air. FIG. FIG. 1 is a diagram illustrating a spray air (compressed air) supply circuit, a flux supply circuit, and a control device in a symbol diagram.

In the flux coating apparatus of the present embodiment shown in FIGS. 1 and 2, in addition to the configuration of the conventional flux coating apparatus shown in FIG. 8, a flux supply circuit and a spray air It shows a supply circuit, a gate air supply circuit, a supply control circuit thereof, a temperature control means, and the like.

In FIG. 1, components for spraying and applying a flux to a workpiece to be flux-coated are almost the same as those in the prior art shown in FIG.

That is, the printed wiring board 1, which is a plate-shaped workpiece to be coated with a flux, holds both ends of the printed wiring board 1 on two parallel conveyors 2 corresponding to the width of the printed wiring board 1. The flux 4 is conveyed in the direction of the arrow A, and the flux 4 is sprayed from a spray nozzle portion 3a of a spray nozzle 3 provided below the conveyor 2 in FIG. 1 so as to face the flux application surface 1a of the printed wiring board 1. The configuration is such that the spray flux 4a is applied and applied to the flux application surface 1a of the printed wiring board 1.

The spray nozzle 3 is a two-fluid nozzle for supplying a flux 4 to be sprayed and air for spraying (spray air) 5.

The gate air 6 is for opening and closing a needle valve (not shown) in the spray nozzle 3 and is a means for controlling start and stop of spraying of the flux 4.

On the other hand, the spray flux 4 a that is not applied to the printed wiring board 1 is sucked in by the exhaust fan 7 in the direction of arrow B together with the air (atmosphere) around the exhaust hood 8 and is sucked. Are collected, collected and removed, and then exhausted from the exhaust duct 10.

The transport conveyor 2 is constituted by a transport chain (not shown) stretched between the guide sprocket 11 and a driving sprocket 14 driven by the motor 12, and includes a pin (not shown) provided on the transport chain. This is a mechanism in which a side end of the printed wiring board 1 is placed on the top, supported, and transported.

[0059] Further, the motor evening 12 is provided with an encoder 13 for detecting the rotation, the rotation angle from the encode signal S _E, is configured to detect a turn conveyance distance and the conveying speed of the conveyor 2 .

Further, the entry sensor 15 is a sensor for detecting that the printed wiring board 1 has been carried in from the carry-in port 16 and has entered the direction of the spray nozzle 3, that is, the spray position. Specifically, a reflection type optical sensor or the like is used.

The timing at which the flux 4 is sprayed from the spray nozzle 3 is determined by the entry sensor 15.
Detects that but is carried, and in proportion to the conveying distance of the conveyor 2 with reference to the encoded signal S _E output, the flux 4 when the front end of the printed wiring board 1 has reached the position of the spray nozzle 3 Spraying is started, and when the rear end of the printed wiring board 1 reaches the position of the spray nozzle 3, the spraying of the flux 4 is controlled to be stopped.

Although not shown in FIG. 1, the spray nozzle 3 is swung with the nozzle base 3b fixed to the slider 71 of the swing device 70, as shown in FIG. The flux 4 is sprayed and applied while the spray nozzle 3 is swung in a direction orthogonal to the transport direction A of the printed wiring board 1 (a direction perpendicular to the paper surface of FIG. 8, that is, a width direction of the printed wiring board 1).

The spray nozzle 3 is composed of a nozzle base 3b and a spray nozzle 3a in the same manner as a normal two-fluid nozzle, so that the spray nozzle 3a can be attached or detached or replaced. The flux 4 is supplied to the nozzle base 3b by a pipe 19, and the spray air 5 and the gate air 6 for controlling the start and stop of the spray of the flux 4 are formed.
Are supplied by two pipes 18 respectively.

However, unlike FIG. 8, the nozzle base 3b has a supply port 3c to which a pipe 19 for supplying the flux 4 is connected and a reflux port 3d to which a pipe 25 for refluxing the flux 4 is connected. This is a configuration that is used for supplying and refluxing the flux.

As shown in FIG. 2 (a), the nozzle base 3b is provided with only one supply port 3c for the flux 4 and, for example, as shown in FIG. "-Shaped or" Y "-shaped branch means 20 is provided.
It may be configured such that the flux 4 can be circulated by setting the value to 0.

The flux supply tank 22 is normally used in a closed state.
2 is supplied with flux pressurized air 24 from a pipe 23 to apply pressure to the flux 4 contained in the flux supply tank 22, and this pressure is applied to the spray nozzle 3.
This is a configuration for supplying a flux to the device. Therefore, the flux pressurized air 2 supplied to the flux supply tank 22
By the pressure of 4, the flow rate of the spray flux 4a sprayed from the spray nozzle 3 can be adjusted.

In this embodiment, as shown in FIG. 1, a flow path for supplying the flux 4 from the flux supply tank 22 to the spray nozzle 3, that is, the pipe 19 and the flux 4 not sprayed from the spray nozzle 3 are supplied to the flux supply tank. 22 is provided with a pipe 25 for reflux
And a flux circulation pump 26 is provided in the middle of the pipe 19 for supplying the flux 4.
The flux 4 circulates between the flux supply tank 22 and the spray nozzle 3. Even if the operation of the flux circulation pump 26 is stopped, the flux 4 is supplied to the spray nozzle 3 by the pressure applied to the flux 4, so that the spray of the flux 4 is not affected at all.

The spray air 5 and the gate air 6
The flux pressurized air 24 is supplied from a compressed air supply device 27 such as a compressor, etc., and after removing impurities by a filter 29 through an on-off valve 28, is adjusted to a target pressure by each pressure control valve 30. Further, it is configured to supply the fuel to the spray nozzle 3 and the flux supply tank 22 via the electromagnetic valve 31. In addition, the pressure gauge 32 is for pressure monitoring.

A relief type pressure control valve is used as the pressure control valve 30 for controlling the pressure of the flux pressurized air 24 supplied to the flux supply tank 22. this is,
This is because, even when the flux 4 is supplied to the flux supply tank 22, the pressure in the flux supply tank 22 is maintained at a controlled predetermined value.

Further, the flux supply tank 22 is provided with a heat exchanger 33 for heating and cooling the flux 4 to control the temperature to a target temperature. And the like. The temperature sensor 35 is means for detecting the temperature of the flux 4. The temperature control device 34 controls the output power P _HF with reference to the detection signal S _TF of the temperature sensor 35 to control the temperature adjusted in advance. To maintain the temperature of the flux 4.

Instead of the heat exchanger 33 and the temperature control device 34 such as a heat pump, a temperature control means using a Peltier element may be provided. The Peltier element is convenient because it can switch between heating and cooling only by changing the direction of current flow.

If the flux 4 only needs to be heated and heated, a heater with a small electric power is provided to heat the flux so that the heating saturation temperature falls within a predetermined temperature range. Is also good. Further, a heater with a thermostat may be provided, or a heater of a self-temperature control type may be provided.

Further, the flux supply tank 22 is provided with a liquid level sensor (second liquid level sensor) 37.
It is configured so that the amount of the contained flux 4 can be detected.

On the other hand, an external storage tank 40 for replenishing the flux is provided outside the flux coating device, and a supply port for supplying the flux 4 to the flux supply tank 22 from the outlet 46 of the external storage tank 40 is provided. Pump 41 and pipe 42 forming a flow path for replenishment thereof
Are provided. A check valve (backflow prevention means) 4 for flowing the flux 4 only from the external storage tank 40 to the flux supply tank 22 is provided between the supply pump 41 and the pressurized flux supply tank 22.
3 is provided. The check valve 43 is a means for preventing the flow of the flux 4 from flowing back, thereby preventing the pressure in the flux supply tank 22 from fluctuating and the spray flow rate of the flux 4 from fluctuating. Therefore, if the pump 41 is a pump having the same function of suppressing the reverse flow as the check valve 43 (backflow prevention function), there is no need to provide the check valve 43.

The external storage tank 40 is also provided with a liquid level sensor (first liquid level sensor) 44 so as to detect the amount of the contained flux 4. The liquid level sensor 44 and the supply pipe 42 are fixed to the lid 45 of the external storage tank 40 so that the external storage tank 40 can be easily replaced.

Then, a spray control device 47 for controlling the start and stop of spraying of the flux 4, a circulation pump control device 48 for controlling the operation of the circulation pump 26, and a supply pump for controlling the operation of the supply pump 41. The control device 49 and an empty notification device (including a notification unit 50a) 50 for notifying that the amount of the flux 4 stored in the external storage tank 40 has become equal to or less than a predetermined amount and issuing the notification are provided.

The spray control device 47 is constituted by a computer system.
Of the detection signal S _I, pumping signal S _Pl from the encode signal S _E and the circulation pump controller 48 of the encoder 13 of the conveyor 2 is input, 3 from the output port
Each outputs the spray air supply solenoid valve control signal S _S, Getoea supply solenoid valve control signal S _G and flux supply tank pressurized air supply solenoid valve control signal S _TP in pieces of the solenoid valve 31.

[0078] circulation pump controller 48 is also Yes constituted by a computer system, from the input port, detection signals S _L and the spray control unit 47 of the detection signal S _TF and liquid level sensor 37 of the temperature sensor 35 of the flux supply tank 22 and Getoea supply solenoid valve control signal S _G from are inputted,
The output port outputs an operation control signal P _Pl of the circulation pump 26 and a circulation pump operation signal S _Pl . In addition,
The output circulation pump operation signal S _Pl is transmitted to the spray control device 47 to be notified.

The air notification device 50 is also constituted by a computer system, and a detection signal S _R from a liquid level sensor 44 provided in the external storage tank 40 is input to an input port, and a predetermined liquid level (ie, flux) is determined. 4) or less, activates the issuing unit 50a (means for notifying the manager in charge by a warning lamp, a warning sounder, etc.) and outputs an empty notification signal S _A from the output port to supply the refill pump control device. Notify 49.

The supply pump control unit 49 is also a computer system.
And is installed in the flux supply tank 22.
Detection signal S of the liquid level sensor 37_L And the empty notification signal
No. S _A Is input to the input port, and
Operation control signal P of supply pump 41_P2Is output. sand
That is, when the liquid level of the flux supply tank 22 is determined in advance.
If the liquid level falls below a certain level (that is, the amount of flux 4),
The amount of flux 4 in the external storage tank 40 is predetermined
When the liquid level is higher than a predetermined level (that is, the amount of flux 4)
The supply pump 41 is operated.

As shown in FIG. 2 (b), when means for controlling the spray air 5 supplied to the spray nozzle 3 to a predetermined temperature is provided, the printed wiring board 1 sprayed from the spray nozzle 3 The temperature of the spray flux 4a to be applied to the substrate can be controlled more precisely. That is, the spray flux 4a which has been atomized in the spraying process of the flux 4 is wrapped in the temperature-controlled spray air 5, so that it is difficult to raise or lower the temperature in the spraying process.

Of course, the temperature of the spray flux 4a may be set to be positively raised or lowered by the spray air 5.

That is, the configuration of FIG. 2B is a configuration in which the spray air 5 supplied to the spray nozzle 3 is controlled to a predetermined temperature in the temperature control chamber 52. 5 is provided with a heat exchanger 53 for heating or cooling to control the temperature to a target temperature, and the heat exchanger 53 is provided with a temperature control device 54 such as a heat pump. The temperature sensor 55 is the spray air 5
The temperature controller 54 operates with reference to the detection signal _STA of the temperature sensor 55 to maintain the temperature of the spray air 5 at a preset and set temperature.

Instead of the heat exchanger 53 and the temperature control device 54 such as a heat pump, a temperature control means using a Bertier element may be provided. A Bertier device is convenient because heating and cooling can be switched by simply changing the direction of current flow.

When only heating and raising the temperature of the spray air 5 is required, a heater with a small electric power is provided to heat the spray air 5 so that the heating saturation temperature falls within a predetermined temperature range. You may comprise. Further, a heater with a thermostat may be provided, or a heater of a self-temperature control type may be provided.

In addition to the above, in the flux coating apparatus of this embodiment shown in FIG. 1, a heating / drying device 57 is provided as a means for heating / drying the flux 4 on the downstream side of the spray nozzle 3.
Is provided. In the example of FIG. 1, the printed wiring board 1 is irradiated with the infrared rays radiated from the heater 58 and the hot air blown by the blowing fan 59 onto the flux-coated surface 1 a of the printed wiring board 1 after the flux application, and blowing it. It is configured such that the flux 4 applied to the substrate can be immediately dried. The wind direction adjuster 60 is a means for adjusting the direction of hot air blown to the printed wiring board 1.

The heating / drying device 57 is provided with a control device 63. Then, the control device 63 is provided with a temperature regulating device 64 of the heater 58, with reference to the detection signal S _D of the temperature sensor 61 provided on the surface of the heater 58, adjust power P _D applied to the heater 58 Then, the surface temperature of the heater 58 is controlled to a predetermined temperature. Further, the blower fan 59 is configured so as to be able to adjust the rotation speed thereof and thus the blower flow rate of the hot air. That is, a rotation speed adjusting device 65 such as an inverter is provided in the control device 63 and the blower fan 59 is provided.
It is configured to be adjusted to supply power and frequency P _F to the motor (not shown) for driving the.

The notification signal S _C output from the control device 63 shown in FIG. 1 is a signal for notifying the subsequent soldering device (not shown) that the heating / drying device 57 is operating. When the control unit of the soldering apparatus receives the notification signal S _C , the control unit operates to automatically lower the heating output (electric power such as infrared rays or hot air) of the preheating means.

The degree of decrease in the heating output of the preheating means in the soldering apparatus is determined by referring to a data table stored in the control unit in advance. This data table includes the application parameters of the flux application device and the operation parameters of the heating / drying device 57 (for example, the flux application flow rate measured by a flow meter (not shown), the detection signal _SD of the temperature sensor 61 of the heater 58 and the hot air temperature, The correspondence between the wind speed of the hot air and the desired degree of heating of the printed wiring board 1 (for example, the temperature of the printed wiring board) is created as data standardized in advance by actual measurement or the like, and this data is tabulated to create a table. And create it.

Therefore, the control unit of the soldering apparatus, having received the notification of these parameters, adjusts the heating output of the preheating means with reference to the data table, and adjusts the preheating temperature before soldering the printed wiring board 1. Control can be performed so as to reach a target temperature specified in advance. In addition,
As an example of the technique of such a soldering apparatus, there is a technique disclosed in Japanese Patent Application Laid-Open No. Hei 9-186451. Such a configuration of the distributed management system by communication has become a common means in the FA field.

By the way, in this embodiment, heating and
It is preferable that the hot air blown from the drying device 57 is blown toward the carry-out port 17 so that the hot air does not flow toward the spray nozzle 3. Only hot air may be blown in the direction of the flux application surface 1a of the printed wiring board 1. Further, in order to further promote the drying, a configuration may be adopted in which the moisture in the air is removed by a dehumidifier to supply low-humidity dry air to the heating / drying device 57. In drying the water-soluble flux, it is preferable to irradiate an infrared ray having a wavelength that the aqueous solvent can most easily absorb.
The wavelength of the infrared light mainly emitted from the heater 58 can be easily selected by changing the type of the infrared emitting material coated on the surface.

Although not shown, the printed wiring board 1
When the ultrasonic wave is applied to the surface 1a to be coated with the flux, the applied flux 4 is vibrated to generate fine waves on its surface, whereby the surface area is enlarged and the drying thereof can be accelerated. Therefore, by using such an ultrasonic irradiation means in combination, the drying of the flux 4 can be further promoted.

Further, although not shown, a particle beam irradiating means such as plasma is provided to irradiate the flux-coated surface 1a of the printed wiring board 1 with a particle beam such as plasma.
Thereby, heating and drying can be promoted. In this case, it is known that the activation of the flux 4 can be promoted by utilizing the plasma CVD method by appropriately selecting the composition of the flux 4 to be applied and the type of the plasma generating gas. (2) Operation Next, the operation of the flux application device of the present embodiment will be described. In this operation description, the operation of each control device will be described in order, and the description will be developed as a process in which the flux is finally sprayed, applied to the printed wiring board, and applied. Further, a case where there is a variation of each operation will be described each time.

Operation of Empty Notification Apparatus for External Storage Tank (Air Notification Procedure) Since the empty notification apparatus 50 is constituted by a computer system, its control procedure can be realized by software.

Referring to FIG. 3, the procedure for performing an empty notification of the external storage tank will be described.

FIG. 3 is a flowchart for explaining a procedure in which the empty notification device of the external storage tank issues an empty notification.

That is, in step S11, the liquid level sensor 4 determines whether or not the liquid level in the external storage tank 40 is empty.
The determination is made with reference to the detection signal S _R of No. 4 (determined based on whether or not the liquid level is lower than a predetermined liquid level). Then, when it is determined that it has become empty, the process proceeds to step S12, and the notification unit 50a is operated to notify the manager. Subsequently, the process proceeds to step S13, in which the external storage tank 40 is notified to the replenishment pump control device 49 by the empty signal S _A that the empty state is in an empty state.
Return to

On the other hand, if it is determined in step S11 that the external storage tank 40 is not empty, the process proceeds to step S14.
Then, the issuing unit 50a is stopped. Subsequently, the process proceeds to step S15, and the empty signal S _A is not notified to the supply pump control device 49. Then, the process returns to step S11 to repeat the above procedure.

That is, when the external storage tank 40 becomes empty and the liquid level becomes such that the supply of the flux 4 by the replenishing pump 41 becomes impossible, the empty notification device 50 causes the issuing unit 50a to issue a notification to the manager. And the empty signal S
_A is notified to the supply pump control device 49 to stop the operation of the supply pump 41 (described later in the operation control procedure of the supply pump).

Operation of Supply Pump Control Device (Operation Control Procedure of Supply Pump) Since the supply pump control device 49 is constituted by a computer system, the control procedure can be realized by software.

The control procedure of the supply pump control device will be described with reference to FIG.

FIG. 4 is a flowchart for explaining a procedure in which the supply pump control device controls the operation of the supply pump.

That is, in step S21, it is determined whether or not the empty notification signal S _A has been notified from the empty notification device 50, and only when there is no notification of the empty signal S _A does step S22 occur.
Move to. Then, in step S22, the liquid level sensor 37
Of the detection signal S _L with reference to the liquid level predetermined prescribed level of the flux supply tank 22 (LOW: for example, 1/3 of the maximum liquid level) determines whether or not lower than lower Only if it is, the process proceeds to step S23 to start the operation of the supply pump 41.

[0104] Then, the process proceeds to step S24, the detection signal S _L with reference to the liquid level predetermined prescribed level of the flux supply tank 22 (HI: e.g., the maximum liquid level 2 /
It is determined whether it is higher than 3). If it is higher, the process proceeds to step S25 to stop the operation of the supply pump 41, and then returns to step S21.

If the liquid level in the flux supply tank 22 is lower than the predetermined liquid level (HI) in step S24, the flow shifts to step S26, where a notification empty signal S _A is notified from the empty notification device 50. It is determined whether or not the empty notification signal S _A has been notified, and the process proceeds to step S25 to stop the operation of the supply pump 41, and thereafter returns to step S21. However, if there is no notification of the empty notification signal S _A in step S26, the process returns to step S24 and repeats.

As described above, the supply pump control device 49
The replenishing pump 41 is operated so that the level of the flux 4 in the flux supply tank 22 and, consequently, the amount of the flux 4 is maintained within a predetermined range. If the flux 4 in the external storage tank 40 is empty, Pump 41 for replenishment
Is controlled not to operate.

Operation of Circulating Pump Controller (Operation Control Procedure of Circulating Pump) Since the circulating pump controller 48 is constituted by a computer system, the control procedure can be realized on software.

The control procedure of the circulating pump control device will be described with reference to FIG.

FIG. 5 is a flowchart illustrating a procedure for controlling the operation of the circulation pump by the circulation pump control device.

[0110] That is, in step S31, flux supply tank 2 with reference to the detection signal S _L of the liquid level sensor 37
It is determined whether or not the liquid level 2 and thus the amount of the flux 4 is equal to or greater than a predetermined minimum amount (EMP: for example, 1/5 of the maximum liquid level). The process moves to S32. In step S32, the predetermined temperature range the temperature is predetermined detection signal S _TF with reference to the flux 4 of the temperature sensor 35 _(T T ± △ T:
For example, it is determined whether the temperature is within 50 ° C. ± 5 ° C., and only when the temperature is within the predetermined temperature range (T _T ± ΔT), the process proceeds to step S33, and the circulation pump 26 is in an operable state. A circulating pump operable state notification signal S _Pl for notifying that there is, is output to the spray control device 47. And
The process proceeds to step S34 to operate the circulation pump 26.

[0111] Then, the process proceeds to step S35, a predetermined minimum amount of liquid level and hence the amount of the flux 4 reference to flux supply tank 22 has predetermined detection signal S _L of the liquid level sensor 37 (EMP) or whether Is determined, and if it is equal to or greater than the minimum amount (EMP), the process returns to step S32 and is repeated. However, if it is determined in step S35 that the amount of the flux 4 is equal to or less than the predetermined minimum amount (EMP), the process proceeds to step S36, and the operation of the circulation pump 26 is stopped. Thereafter, the process returns to step S31 and is repeated.

Thus, the circulation pump control device 48
It operates only when the amount of the flux 4 necessary for circulating the flux 4 by the circulation pump 26 is stored in the flux supply tank 22 and the temperature of the flux 4 is a predetermined temperature. Is controlled as follows.

As described in the section (1), when a heater having a small electric power is provided to heat the flux so that the heating saturation temperature falls within a predetermined temperature range. When a heater with a thermostat or a self-temperature control type heater is provided, a predetermined temperature or more (for example, 3
(0 ° C. or more), the process may proceed to step S33. Further, the attachment of the temperature sensor 35 may be omitted, and the control in step S32 may be omitted.

Further, in FIG.
Gate air supply solenoid valve control signal S _G Or dedicated notifications
Signal S_PKIs input to the circulating pump control device 48;
Then, in FIG. 5, step S33 and step S34
A new control step (hereinafter referred to as “insertion step”)
) And a pump for circulation while spraying flux 4
26 may not be operated.

That is, in this insertion step, the gate air supply solenoid valve control signal S _G (or the notification signal S _PK )
Referring to the flux 4 is determined whether a spray (as will be described later, is supplied Getoea 6 to the spray nozzle 3 is output Getoea supply solenoid valve control signal S _G, thereby a needle valve of the spray nozzle 3 When is opened, spraying is possible.) If not spraying, the process proceeds to step S34 to operate the circulation pump 26, and when it is determined that the flux 4 is sprayed in this insertion step, The control may proceed to step S36 to stop the circulation pump 26.

As is apparent from FIG. 1, even if the pump 26 for circulating the flux 4 is not operated,
Since the pressure is applied to the flux 4 by the flux pressurized air 24 supplied to the flux supply tank 22, the flux 4 is supplied to the spray nozzle 3 through a reflux pipe 25 of the flux 4. Therefore, the state of the circulation pump 26, that is, the operation / stop thereof, does not affect the spraying of the flux 4.

Operation of Spray Control Device (Control Procedure of Spray Timing and Spray Control Procedure) Since the spray control device 47 is constituted by a computer system, the control procedure can be realized by software. The computer system is managed by a time sharing system, and is configured so that a plurality of control procedures (processes) can be performed in parallel.

A control procedure of the spray control device will be described with reference to FIGS.

FIG. 6 is a flowchart for explaining a procedure in which the spray control device obtains the spray timing. FIG. 7 is a flowchart illustrating a control procedure in which the spray control device performs the spray control. Then, the procedure of steps S41 to S45, the procedures of steps S46 to S50, and the procedures of steps S51 to S55 are processed in parallel by the time sharing system.

That is, as shown in FIG.
At 41, the detection signal S of the entry sensor 15 _I See pudding
Judge whether the front end of the wiring board 1 is detected, and detect the front end.
Only when it is output, the process proceeds to step S42 to
A. Encoding signal S of encoder 13_E Count
(At this time, the count number = N_H And).

Thereafter, the flow shifts to step S43, where the count number N _H is a predetermined value (N _P : this predetermined value N _P is determined from the position where the entry sensor 15 detects the front end of the printed wiring board 1 in FIG. spray flag (but determines whether a number of encoded pulses) corresponding to the transport distance to reach above the spray nozzle 3, it proceeds only to a step S44 when a predetermined value (N _P) Set F _F ). That is, the timing at which the spray flag (F _F ) is set is the spray start timing of the flux 4.

Thereafter, the flow shifts to step S45 to clear the counted number _NH , and returns to step S41 to repeat the above procedure.

[0123] Further, with reference to the detection signal S _I of the entrance sensor 15 in step S46 determines whether it has detected the trailing edge of the printed wiring board 1, and proceeds to only step S47 if it detects the trailing edge Te starts counting the encode signal S _E of conveyor 2 the encoder 13 (at this time,
Count number = _NT ).

Thereafter, the flow shifts to step S48, where the count number _NT is a predetermined value (N _P : this predetermined value N _P is determined from the position where the entry sensor 15 detects the rear end of the printed wiring board 1 in FIG. rear end determines whether a number of encoded pulses) corresponding to the transport distance to reach above the spray nozzle 3, the operation proceeds to only step S49 when a predetermined value (N _P) sprayed Reset the flag (F _F ). That is, the timing at which the spray flag (F _F ) is reset is the spray stop timing.

Thereafter, the flow shifts to step S50 to clear the count number _NT , and returns to step S46 to repeat the above procedure.

When the spray start timing and the spray stop timing are obtained as described above, the spray of the flux 4 is performed according to the spray control procedure of FIG. That is, in step S51, it is determined whether or not the circulation pump 26 is in an operable state with reference to the circulation pump operable state notification signal S _Pl of the circulation pump 26. This circulation pump 26
As described in the previous section, the circulating pump operable state notification signal S _P1 is output when the circulating pump 26 for the flux 4 is in operation, and the spray control device 4
7 is output even when the pump 26 for the circulation of the flux 4 is stopped by the input of Getoea supply solenoid valve control signal S _G to be output.

Then, in step S51, the process proceeds to step S52 only when the pump 26 for circulating the flux 4 is in an operable state. Then, in step S52, it is determined whether or not the spray flag (F _F ) is set. Only when the flag is set, the process proceeds to step S53 to supply the gate air 6 and the spray air 5. That opens the solenoid valve 31 to ON spray air supply solenoid valve control signal S _S with by ON the Getoea supply solenoid valve control signal S _G to open the solenoid valve 31, to start spraying the flux 4.

In step S52, the spray flag (F
_{If F} ) is not set, the flow returns to step S51 to repeat the above procedure.

After the spraying of the flux 4 is started in step S53, the process proceeds to step S54, where it is determined whether or not the spray flag (F _F ) has been reset. If so, the process proceeds to step S55. Then, the supply of the gate air 6 and the spray air 5 is stopped. That is, Getoea supply solenoid valve control signal S _G OFF the by the solenoid valve 31 to close with spray air supply solenoid valve control signal S
_S is turned off, the electromagnetic valve 31 is closed, and the spraying of the flux 4 is stopped.

In step S54, the spray flag (F
_{If F} ) has not been reset, the process returns to step S51 and the above procedure is repeated.

Also, if the circulation pump 26 is not in the operable state in the previous step S51, the flow shifts to step S55, and the spraying of the flux 4 is stopped.

As described above, only when the circulation of the flux 4 is performed while the pump 26 for circulating the flux 4 is operable and the printed wiring board 1 is conveyed onto the spray nozzle 3, the spray nozzle A flux 4 is sprayed from 3, and the flux 4 is applied to the printed wiring board 1.

As an example of the control variation described above, even when the circulation pump 26 is controlled to be stopped while the flux 4 is being sprayed, the circulation pump control device 48 controls the circulation pump 26. since pumping signal S _Pl of is notified to the spray control unit 47, the spray flux 4 is continued.

As described above, in the flux coating apparatus of the present embodiment, the circulation flow path (constituted by pipes 19 and 25) is used when supplying the flux 4 stored in the flux supply tank 22 to the spray nozzle 3. Keep it,
The flux 4 is circulated through the circulation channel. Therefore, the flux 4 which is stored in the flux supply tank 22 and has a stable temperature can always be supplied to the spray nozzle 3. Furthermore, even when the distance between the flux supply tank 22 and the spray nozzle 3 is large, there is no change in the temperature of the flux 4, and the flux 4 with a stable temperature can be supplied to the spray nozzle 3.

For this reason, when the flux supply flow path between the spray nozzle 3 and the flux supply tank 22 is long,
Even in a flux applying apparatus configured to apply the flux 4 to the printed wiring board 1 while swinging the spray nozzle 3, the flux 4 having a stable temperature can be supplied. In particular, when the spray nozzle 3 swings, the flux supply flow path (pipe 19) between the spray nozzle 3 and the flux supply tank 22 also swings. Also, it is difficult to keep the temperature and the like, and the technology of the present embodiment is extremely important.

The flux 4 in the flux supply tank 22 can be stably maintained at a target temperature by the temperature control device 34. Therefore, the flux 4 supplied to the spray nozzle 3 by the circulation of the flux 4 Is extremely stable.

As described above, since the temperature of the flux 4 supplied to the spray nozzle 3 can be maintained extremely stably, it is possible to stably maintain the properties of the flux 4 such as viscosity and surface tension. The physical properties of the spray flux 4a sprayed from 3 into a mist state are also extremely stable, the spray flow rate and the spray particle diameter are stable, and the flux 4 to be applied to the printed wiring board 1 is always applied under stable conditions. This makes it possible to apply the flux 4 uniformly and stably at all times.

Further, as illustrated in FIG. 2, by keeping the temperature of the spray air 5 constant, the temperature of the atomized flux 4, ie, the spray flux 4a, can be stably maintained. Become. That is, the spray flux 4a, which has been sprayed and atomized and the heat capacity of the individual flux particles has become extremely small, exchanges heat with the spray air 5 quickly during spraying, so that the temperature of the atomized spray flux 4a is reduced. Is controlled to be equal to the temperature of the spray air 5.

Therefore, by adding the configuration shown in FIG. 2B to the flux coating apparatus having the configuration shown in FIG. 1, the temperature of the flux 4 to be sprayed can be controlled more accurately and maintained stably. . In this case,
It is desirable that the temperature of the flux 4 in the flux supply tank 22 and the temperature of the spray air 5 are set to be the same.

However, since the printed wiring board 1 can be heated by the spray air 5, the temperature of the spray air 5 is set higher than the temperature of the flux 4 when the printed wiring board 1 is to be heated positively. You may. Heating the printed wiring board 1 early is effective in promoting early drying of the flux 4 and in preventing the flux 4 from penetrating the printed wiring board 1. Therefore, it is useful and important to set such a temperature.

The supply amount of the flux 4 in the flux supply tank 22 is controlled by the replenishing pump control device 49. In the present embodiment, the liquid level is, for example, 1/3 to 2/3 of the maximum liquid level. Maintained in range. In addition, the circulation pump control device 48 allows the amount of the flux 4 in the flux supply tank 22 to be, for example, 1 at the maximum liquid level when viewed from the liquid level.
At / 5 or more, the circulation pump 26 is operated.

That is, the minimum flux storage amount is set to be larger (１ ／ of the maximum liquid level) than the liquid level (１ ／) at which the circulation pump 26 can operate, and the flux 4 in the flux supply tank 22 is set. Is 1/3 of the maximum liquid level
It is maintained within a narrow range of about 2/3.

Therefore, the flux 4 is supplied to the flux supply tank 22 by the pump 41 for supplying the flux 4.
Is supplied, the temperature of the flux 4 does not fluctuate abruptly and is controlled within a predetermined temperature range by the temperature control device 34.

The supply flow rate of the supply pump 41 per unit time is determined so that the temperature of the flux 4 in the flux supply tank 22 is controlled within a predetermined temperature range by the temperature control device 34. Further, a lower limit and an upper limit of the amount of the flux 4 stored in the flux supply tank 22 are set.

If the maximum heat exchange amount per unit time controlled by the temperature control device 34 is increased, the flux 4 in the flux supply tank 22 by the flux 4 replenished by the flux replenishing pump 41 is used.
Can be reduced.

Further, in this embodiment, since the flux 4 supplied to the spray nozzle 3 is supplied from the flux supply tank 22, even if the external storage tank 40 becomes empty, the flux application device is kept in the operating state. As it is, that is, while applying the flux 4 to the printed wiring board 1, the external storage tank 40 in which the flux 4 is sufficiently filled can be replaced. Therefore, it can be used continuously without stopping the operation of the flux coating device. Note that this replacement time is determined by the
Is notified to the person in charge of management by the issuing unit 50a.

Next, as illustrated in FIG. 1, the printed wiring board 1 on which the flux 4 has been applied is immediately dried by the heating / drying device 57 by the solvent component of the flux 4. Therefore, the applied flux 4 can be sufficiently dried at the time of soldering, without the flux 4 penetrating into the printed wiring board 1.

Therefore, when soldering is performed by a soldering device provided at a subsequent stage, bubbles and solder balls do not occur, and thus there is no occurrence of defective soldering or deterioration in quality. As a result, the printed wiring board 1 having good and stable soldering quality can be manufactured.

In addition to the heating / drying device 57 shown in FIG. 1, a heater for infrared irradiation and a heater for hot air heating are separately provided, and the surface temperature and hot air temperature of the heater for infrared irradiation can be controlled separately. As described above, a configuration may be adopted in which a temperature control device is provided for each. Moreover, you may comprise so that a hot air may be blown in the shape of an air knife.

[0150]

As described above, according to the flux coating apparatus of the present invention, the following effects can be obtained.

That is, according to the first aspect of the present invention, even when the flux supply container and the spray nozzle are provided at positions separated from each other, the flux stays in the flux flow path for a long time to cause a temperature change. Disappears. Therefore, physical properties such as viscosity and surface tension of the flux supplied to the spray nozzle can be constantly maintained at a constant level, and a stable spray of the flux such as a spray flow rate and a spray particle diameter can be performed. The flux can be uniformly applied to the flux application work, and can be applied stably over time.

As a result, in the soldering device provided at the subsequent stage of the flux applying device, it is possible to manufacture a work to be soldered, ie, a printed wiring board, which has good soldering quality and is stable over time.

According to the second aspect of the present invention, it is possible to supply the flux in the flux supply container whose temperature has been raised or lowered by the temperature control means to the spray nozzle while maintaining a stable temperature without changing the temperature. Becomes That is, even if the flux supply container and the spray nozzle are provided at positions separated from each other, the flux is circulated between the spray nozzle and the circulation flow path of the flux and the flux supply container, so that the flux is accommodated in the flux supply container. It is possible to always supply a flux having the same temperature as the temperature of the flux to the spray nozzle.

Therefore, it is possible to constantly maintain the physical properties such as the viscosity and surface tension of the flux supplied to the spray nozzle, and it is possible to spray the flux with a stable spray flow rate and spray particle size. The flux can be uniformly applied to the workpiece to be coated with the flux and stably with time.

As a result, in the soldering device provided at the subsequent stage of the flux applying device, it is possible to manufacture a work to be soldered, ie, a printed wiring board, which has good soldering quality and is stable over time.

According to the third aspect of the present invention, the flux is applied to the printed wiring board while maintaining the target properties such as viscosity and surface tension by controlling the spray air to the target temperature. It is possible to stabilize the spray particle size and the like, and to stably maintain the particle distribution of the mist-like flux and the spread of the applied flux when applied to the printed wiring board in a desired state. Become like

Therefore, the flux can be applied and applied stably with time without unevenness on the work to be applied with flux.

In particular, by using the invention of claim 3 together with the invention of claims 1 and 2, the temperature of the flux applied to the printed wiring board can be precisely controlled. Become like

Further, by setting the temperature of the spray air to be high, the printed wiring board can be heated at the same time, and the early drying of the applied flux can be promoted.

Further, according to the present invention, the solvent component can be immediately dried after the flux is applied to the printed wiring board. Therefore, it is possible to prevent the penetration of the solvent into the printed wiring board, and it is possible to perform high-quality printed wiring board soldering without generating bubbles or solder balls during soldering. Become like In particular, the effect is large in VOC free flux.

According to the fifth aspect of the present invention, the flux can be applied to the workpiece to be flux-coated without stopping the flux coating operation of the flux coating apparatus. That is, the external storage container of the empty flux can be replaced with an external storage container in which the flux is sufficiently stored without stopping the flux application operation. In addition, the temperature of the flux in the flux supply container does not suddenly change, and the flux application operation can be continued without changing the physical properties of the flux.

Furthermore, the flux in the flux supply container does not flow backward, and bubbles such as air are not supplied to the flux supply container due to the idle operation of the pump. As a result, when the external storage container is emptied or the external storage container is replaced, the flux spray flow rate does not change, and it is possible to continuously and stably spray the flux. Can be operated continuously.

As a result, the same flux application that does not change with time can be applied to any printed wiring board to which the flux is applied, and a stable flux application operation can be performed.

According to the sixth aspect of the invention, the same effect as that of the fifth aspect of the invention can be obtained without separately providing a backflow preventing means such as a check valve.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining an embodiment of a flux coating device of the present invention.

FIG. 2 is a diagram for explaining another example of a flux circulation channel and a configuration of a spray air temperature control unit.

FIG. 3 is a flowchart illustrating a procedure in which an empty notification device of an external storage tank performs an empty notification.

FIG. 4 is a flowchart illustrating a procedure in which the supply pump control device controls the operation of the supply pump.

FIG. 5 is a flowchart illustrating a procedure in which the circulation pump control device controls the operation of the circulation pump.

FIG. 6 is a flowchart illustrating a procedure in which a spray control device obtains a spray timing.

FIG. 7 is a flowchart illustrating a control procedure in which the spray control device performs spray control.

FIG. 8 is a side view showing a conventional spray flux coating apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Printed wiring board 1a Flux coated surface 2 Conveyor 3 Spray nozzle 3a Spray nozzle part 3b Nozzle base part 3c Supply port 3d Reflux port 4a Spray flux 5 Spray air 6 Gate air 7 Exhaust fan 8 Exhaust hood 9 Filter 10 Exhaust duct 11 Guide sprocket 12 Motor 13 Encoder 14 Drive sprocket 15 Entry sensor 16 Carry-in port 17 Carry-out port 18 Pipe 19 Pipe 20 Branching means 22 Flux supply tank 23 Pipe 24 Flux pressurized air 25 Pipe 26 Pump 27 Compressed air supply device 28 Open / close valve 29 Filter Reference Signs List 30 pressure control valve 31 solenoid valve 32 pressure gauge 33 heat exchanger 34 temperature controller 35 temperature sensor 37 liquid level sensor 40 external storage tank 41 pump 42 pipe 43 check valve 44 liquid level sensor 5 Lid 46 Take-out port 47 Spray control device 48 Circulation pump control device 49 Supply pump control device 50 Air notification device 50a Announcement section 52 Temperature control chamber 53 Heat exchanger 54 Temperature control device 55 Temperature sensor 57 Heat drying device 58 Heater 59 Ventilation fan Reference Signs List 60 wind direction controller 61 temperature sensor 63 controller 64 temperature controller

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) B23K 3/00 B23K 3/00 SN H05K 3/34 503 H05K 3/34 503B F-term (reference) 4D075 AA01 AA52 AA55 AA65 AA72 AA76 AA86 CA47 DA06 DB14 DC22 EA05 EC10 4F033 AA01 BA03 DA01 HA01 LA11 LA13 PA11 QA01 QB03X QB19 QK05X QK09X QK12X QK19X 4F042 AA06 BA09 CA08 CB26 5E319 AC01 CD22 CD25

Claims (6)

[Claims] 1. A flux coating apparatus for spraying a flux contained in a flux supply container from a spray nozzle and applying the flux to a workpiece to be flux-coated, wherein a flux flow for circulating the flux between the flux supply container and the spray nozzle. A flux coating device comprising a channel and a pump. 2. A flux coating apparatus for spraying a flux contained in a flux supply container from a spray nozzle and applying the flux to a workpiece to be flux-coated, wherein a temperature for maintaining a temperature of the flux contained in the flux supply container at a predetermined temperature. A flux coating apparatus comprising: a control unit; a flux flow path for circulating flux between the flux supply container and the spray nozzle; and a pump. 3. A flux coating apparatus for spraying a flux contained in a flux supply container from a spray nozzle and applying the flux to a workpiece to be flux-coated, wherein the spray nozzle is a two-fluid nozzle using a gas for spraying and the spray nozzle. A flux control device for maintaining a temperature of the spray gas supplied to the device at a predetermined temperature. 4. A flux application device which is formed separately from a soldering device and sprays a flux contained in a flux supply container from a spray nozzle and applies the flux to a flux application work, wherein the flux application work after the flux application is applied. A flux applying device for heating and drying the flux applied to the substrate. 5. An external part of a flux having a first liquid amount detecting means for storing a flux, detecting the amount of the stored flux and outputting a detection signal, and an outlet for taking out the stored flux. In a flux coating apparatus configured separately from a storage container and spraying a flux contained in a flux supply container from a spray nozzle and applying the flux to a flux application work, a pressure supply for applying pressure to the flux contained in the flux supply container Means, a flow path and a pump for supplying the stored flux from the outlet of the external storage container to the flux supply container, and a reverse flow provided in the flow path and flowing the flux only in the direction of the flux supply container. Inhibiting means for detecting the amount of flux in the flux supply container and detecting A second liquid amount detection unit that outputs a detection signal; and a detection unit that determines the amount of the flux in the flux supply container from the detection signal of the first liquid amount detection unit and the detection signal of the second liquid amount detection unit. A flux application device comprising: control means for operating a pump only when the amount of flux is equal to or less than a fixed amount and the amount of flux in the external storage container is equal to or more than a predetermined amount. 6. The flux coating apparatus according to claim 5, wherein the pump has a backflow preventing function when the pump stops operating and also functions as the backflow preventing means.