JPH05329632A - Flux applying device - Google Patents

Abstract

PURPOSE:To improve the efficiency of a soldering operation by extremely easily putting sprayers into a clean state without spending much labor and time. CONSTITUTION:A flux supply piping 21 for feeding a flux into a flux tank 7 is provided. A diluent supply piping 23 for feeding a diluent to the flux tank 7 is provided. A selector valve 22 for selectively switching the respective flow passages of the flux supply piping 21 and the diluent supply piping 23 to the flux tank 7 is provided. A discharge piping 16 for discharging the flux stored in the flux tank 7 is provided. The flow passage of the flux tank 7 and the diluent supply pipe 23 is communicated by the selector valve 22 to supply the diluent to the flux tank 7 when the flux in the flux tank 7 is discharged by the discharge pipe 16. The diluent is thus sprayed by the ultrasonic sprayers 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flux applying device for applying flux to the lower surface of a printed circuit board on which electronic parts are mounted.

[0002]

2. Description of the Related Art Conventionally, a soldering apparatus for continuously soldering electronic components mounted on a printed circuit board has been
A flux applicator is provided for applying flux to the lower surface side of the printed circuit board in the pre-soldering step.
This flux applying device is configured to spray a liquid flux filled in a flux tank onto a printed circuit board transported by a transport conveyor toward a lower surface of the printed circuit board by a sprayer. The atomizer is an ultrasonic type that atomizes the flux by ultrasonic waves and sprays it, creates a flux film on the peripheral surface of the mesh drum that is rotated, and uses a spray nozzle that is installed on the inner peripheral side of the mesh drum. There are a rotary drum type in which air is jetted toward the lower surface of the printed circuit board to spray the flux from the mesh drum to the lower surface of the printed circuit board, or an air gun type in which the compressed air is sprayed to atomize the flux.

[0003]

By the way, if clogging occurs in the nozzle or mesh of a sprayer that directly sprays and applies the flux whose composition has been adjusted to the lower surface of the printed circuit board, the reliable flux to the lower surface of the printed circuit board is obtained. Is no longer applied and a stable flux of components is not applied, which may interfere with soldering in the next step and may cause defective products. Therefore, in the conventional flux coating device, in order to always keep the sprayer in a clean state,
This sprayer had to be frequently disassembled and cleaned, which required a great deal of labor and time, and the soldering work had to be frequently interrupted for a long time.

The present invention has been made in view of the above circumstances, and it is possible to improve the efficiency of soldering work very easily by keeping the sprayer in a clean state without spending a great deal of labor and time. It is intended to provide a flux coating device.

[0005]

The flux applying apparatus of the present invention is provided in a soldering apparatus, and in a flux applying apparatus for spraying and applying flux onto the lower surface of a printed circuit board conveyed by a conveyor, the flux is accumulated. A flux tank, a sprayer that sprays the flux stored in the flux tank, a flux supply pipe that sends the flux to the flux tank, and a diluent supply pipe that sends a diluent that dilutes the flux to the flux tank, The flux supply pipe and the diluent supply pipe are connected to each other, and the switching valve that selectively switches the respective channels of the flux supply pipe and the diluent supply pipe and the flux tank, and the solvent stored in the flux tank And a discharge pipe for discharging the In order to spray the diluent by the sprayer, when the flux in the flux tank is discharged by the discharge pipe, the diluent supply pipe is connected to the flux tank to supply the diluent into the flux tank. It is characterized by being done.

[0006]

According to the flux applying apparatus of the present invention, when the switching valve connects the diluent supply pipe and the flux tank when the flux in the flux tank is discharged by the discharge pipe, the diluent supply pipe The diluent is supplied from the to the flux tank, and the diluent is stored in the flux tank. Then, by spraying the diluent stored in the flux tank with the sprayer, the sprayer is cleaned with the diluent, and a trouble such as clogging of the sprayer is prevented.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the flux coating device of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 is a flux coating device. This flux applicator 1
Is a coating apparatus main body 2 that sprays flux onto the lower surface of the printed circuit board P, a flux storage tank 3 that stores the flux in which the components are mixed, and a coating apparatus main body that stores the flux stored in the flux storage tank 3. Two
And a flux storage pump 9 for storing a diluent for diluting the flux.
And a diluent supply pump 10 for supplying the diluent stored in the diluent storage tank 9 to the coating apparatus main body 2. As the diluent, isopropyl alcohol (IPA) or the like is used.

As shown in FIGS. 2 and 3, the coating apparatus main body 2 is supported on a frame 6 below a conveyor 5 for conveying the printed circuit board P in the direction of arrow A in FIG. A flux tank 7 is arranged below the No. 5 at a position intersecting the traveling direction of the printed circuit board P.
In the flux tank 7, a plurality of ultrasonic atomizers (atomizers) 8, 8 ... Are respectively supported by shafts X which are rotatably supported, and are rotated by a predetermined angle in the arrow B direction in FIG. The flux stored in the flux tank 7 is atomized by the ultrasonic atomizers 8, 8 ... And sprayed toward the lower surface of the printed circuit board P conveyed by the conveyor 5. ..

A temporary storage tank 12 provided for the purpose of flux concentration control and the like is provided on the side surface on one end side of the flux tank 7 as a supply pipe (flux supply pipe).
This temporary storage tank 11 is connected by 11
In this case, the flux stored in the flux storage tank 3 by the flux supply pump 4 is supplied through the flux supply pipe 21. That is, the flux supplied from the flux supply pump 4 is temporarily stored in the temporary storage tank 12, and then the flux stored in the temporary storage tank 12 passes through the supply pipe 11 and flows into the flux tank 7. ing.

An electromagnetic switching valve (switching valve) 22 is provided in the middle of the supply pipe 11 communicating with the temporary storage tank 12 and the flux tank 7.
Is connected to the other end of a diluent supply pipe 23, one end of which is connected to the diluent storage tank 9 via the diluent supply pump 10. That is, by switching the electromagnetic switching valve 22, either the supply pipe 11 from the temporary storage tank 12 or the diluent supply pipe 23 from the diluent storage tank 9 is connected to the flow path connecting to the flux tank 7 of the coating apparatus main body 2. One can be selectively switched.

At the other end of the flux tank 7, as shown in FIG. 4, a pair of liquid level detection sensors 13A and 13B are provided. These liquid level detection sensors 13A, 13B
Outputs a signal when its tip portion comes into contact with the flux stored in the flux tank 7, and the tip portions are arranged so that their heights are different from each other.

That is, the tip of the liquid level detection sensor 13A is
The ultrasonic atomizers 8, 8 ... Are arranged at the lower limit position of the liquid surface of the flux capable of operating well, and the liquid surface detection sensor 13
B is arranged at the upper limit position of the liquid surface of the flux at which the ultrasonic atomizers 8, 8 ... Can operate well, and based on the detection signals from these liquid surface detection sensors 13A, 13B, The drive is controlled and the liquid level height of the flux in the flux tank 7 is adjusted to be in an optimum state.

Here, when the output of the detection signal from the liquid level detection sensor 13A is stopped, the flux supply pump 4 is driven to supply the flux to the flux tank 7, and the liquid level detection sensor 13B detects the flux. When the signal is output, the driving of the flux supply pump 4 is stopped and the supply of the flux to the flux tank 7 is stopped.

The flux tank 7 is also provided with an overflow tank 14 on its side part, and when the flux in the flux tank 7 becomes a predetermined amount or more,
Excess flux flows in through a discharge port 15 provided at a predetermined height on the side surface of the flux tank 7.

A discharge pipe 16 communicating with the overflow tank 14 is provided on the lower surface of the flux tank 7, and an electromagnetic control valve 17 is provided in the discharge pipe 16 in the middle thereof. That is, this electromagnetic control valve 17
Is opened, the flux in the flux tank 7 flows into the overflow tank 14 through the discharge pipe 16.

The temporary storage tank 12 and the overflow tank 14 are provided with drain valves 25 and 26 on their lower surfaces, respectively.
The fluxes in the respective tanks can be discharged by means of 5 and 26. Further, the flux supply pump 4, the diluent supply pump 10, the electromagnetic switching valve 22, and the electromagnetic control valve 17 are controlled by a control unit (not shown).

According to the flux coating apparatus configured as described above, the flux in the flux storage tank 3 is supplied to the temporary storage tank 12 of the coating apparatus main body 2 by the flux supply pump 4, and the temporary storage tank 12 is further provided. Is fed into the flux tank 7 through the supply pipe 11. Then, the flux stored in the flux tank 7 is sprayed onto the lower surface of the printed circuit board P transported by the transport conveyor 5 at a plurality of locations intersecting the transport direction by the ultrasonic sprayers 8, 8.

Further, these ultrasonic atomizers 8, 8 ... Are sprayed while rotating about the axis of the axis X supported in the width direction, and thereby the legs of the electric / electronic parts mounted on the printed board P are mounted. Flux is sufficiently applied to the rear side in the traveling direction, and soldering in the next step is performed extremely well.

Next, the operation for cleaning the ultrasonic atomizers 8, 8 ... Will be described step by step based on the flow chart shown in FIG.

Step SP1 After the application of the flux to the printed circuit board P is completed,
When a cleaning switch or the like provided in the control unit is pressed to perform the cleaning operation, a control signal is output from this control unit to the electromagnetic control valve 17, and this control signal causes the electromagnetic valve 17 to operate.
Is opened. As a result, the flux in the flux tank 7 passes through the discharge pipe 16 and the overflow tank 14
Shed to. At this point, the flux supply pump 4
Driving is prohibited.

Step SP2 When the liquid level of the flux in the flux tank 7 drops below the tip of the liquid level detection sensor 13A, the liquid level detection sensor 13A no longer detects the liquid level, and this liquid level detection sensor 1
The detection signal from 3A is not output.

Step SP3 In step SP2, the control section confirms that the detection signal is not output from the liquid level detection sensor 13A, the control section outputs a control signal to the electromagnetic control valve 17, and the control signal causes electromagnetic control. The control valve 17 is closed and the flow path of the discharge pipe 16 is closed.

Step SP4 A control signal is output from the control section to the electromagnetic switching valve 22 to switch the electromagnetic switching valve 22, and the electromagnetic switching valve 22 closes the flow path between the flux tank 7 and the temporary storage tank 12, thereby diluting the diluent. The flow path between the diluent supply pipe 23 from the storage tank 9 and the flux tank 7 is opened.

Step SP5 A drive signal is output from the control unit to the diluent supply pump 10, the diluent supply pump 10 is driven, and the diluent stored in the diluent storage tank 9 is supplied to the diluent supply pipe 23. The flux is supplied to the flux tank 7.

Step SP6 The liquid level of the diluent in the flux tank 7 is the liquid level detection sensor 13
When it goes above the tip of B, the liquid level detection sensor 13
B detects the liquid level, and a detection signal is output from this liquid level detection sensor 13B.

Step SP7 In step SP6, the control section confirms that the detection signal is output from the liquid level detection sensor 13B, and the control section outputs a stop signal to the diluent supply pump 10 to supply the diluent. The pump 10 is stopped, and the supply of the diluent to the flux tank 7 is stopped.

Step SP8 A drive signal is output from the control unit to each of the ultrasonic atomizers 8, 8 ... And these ultrasonic atomizers 8, 8 ... Inhale the diluent stored in the flux tank 7 and atomize it. As a result, each of the ultrasonic atomizers 8, 8 ... Is cleaned with the diluent.

Step SP9 When the cleaning operation is performed for a predetermined time in the step SP8, a stop signal is output from the control unit to each of the ultrasonic atomizers 8, 8 ... Will be terminated.

Step SP10 A control signal is output from the control section to the electromagnetic switching valve 22 to switch the electromagnetic switching valve 22, and the electromagnetic switching valve 22 connects the flux tank 7 and the diluent supply pipe 23 from the diluent storage tank 9 to each other. Is closed, and the flow paths between the flux tank 7 and the temporary storage tank 12 are opened.

Step SP11 A control signal is output from the control section to the electromagnetic control valve 17, and the electromagnetic control valve 17 is opened by this control signal. As a result, the diluent in the flux tank 7 passes through the discharge pipe 16 and flows into the overflow tank 14.

Step SP12 The liquid level of the diluent in the flux tank 7 is the liquid level detection sensor 13
When it goes down below the tip of A, the liquid level detection sensor 13
A no longer detects the liquid level, and this liquid level detection sensor 13A
The detection signal from is no longer output.

Step SP13 In step SP12, the control section confirms that the detection signal is no longer output from the liquid level detection sensor 13A, and the control section outputs a control signal to the electromagnetic control valve 17. The electromagnetic control valve 17 is closed, and the discharge pipe 16
Is closed.

Step SP14 The control unit outputs a drive signal to the flux supply pump 4 to drive the flux supply pump 4, and the flux stored in the flux storage tank 3 passes through the flux supply pipe 21 to the temporary storage tank 12. It is supplied and further sent from the temporary storage tank 12 to the flux tank 7.

Step SP15 When the liquid level of the flux in the flux tank 7 rises above the tip of the liquid level detecting sensor 13B, the liquid level detecting sensor 13B detects the liquid level and the liquid level detecting sensor 13B detects the liquid level. The signal is output.

Step SP16 In step SP15, the control section confirms that the detection signal is output from the liquid level detection sensor B, and the control section outputs a stop signal to the flux supply pump 4, and the stop signal outputs the flux. The supply pump 4 is stopped and the supply of flux to the flux tank 7 is stopped.

Step SP17 A drive signal is output from the control unit to each of the ultrasonic atomizers 8, 8 ... And the above-mentioned flux applying operation is performed.

As described above, according to the flux coating apparatus 1 of the above embodiment, the diluent is stored in the flux tank 7, and the diluent is sprayed by the ultrasonic sprayers 8, 8 ... By disassembling and cleaning the sprayer, the ultrasonic sprayers 8, 8 ... Can be cleaned with a diluent very easily without interrupting the soldering work for a long time. It is possible to surely prevent obstacles such as clogging and to apply good flux to the printed circuit board P. As a result, soldering in the next step can be carried out extremely favorably, and defective soldering of electronic components to the printed circuit board P due to defective application of flux can be eliminated.

The flux applying apparatus 1 of the above embodiment
The specific configuration and structure of are not limited to the examples. Here, in the above-described embodiment, the flux whose components have been adjusted in advance (the solid content of rosin or the like has been adjusted) is stored in the flux storage tank 3, and the flux whose components have been adjusted is supplied to the spray device main body 2 by the flux supply pump. 4, the spraying device main body 2 is used as shown in FIG.
The specific gravity sensor 31 is provided in the temporary storage tank 12, and based on the data from the specific gravity sensor 31, the flux in the flux storage tank 3 is mixed with the diluent in the diluent storage tank 9 to adjust to an appropriate component. Alternatively, an automatic specific gravity management device configured to be supplied may be added. Further, in the above embodiment, an example using an ultrasonic atomizer for atomizing the flux by ultrasonic waves has been described, but the atomizer is not limited to the ultrasonic type, and any type of atomizer is used. (Spraying device) may be used.

[0039]

As described above, according to the flux coating apparatus of the present invention, the following effects can be obtained. Since the diluent is stored in the flux tank and the diluent is sprayed with a sprayer, disassembling and cleaning the sprayer does not interrupt the soldering work for a long time, and the sprayer can be used very easily. It can be cleaned with a diluent, and obstacles such as clogging of the sprayer can be reliably prevented, and good flux can be applied to the printed circuit board. This makes it possible to perform soldering in the next step extremely well,
It is possible to eliminate defective soldering of electronic components to a printed circuit board due to defective flux application.

[Brief description of drawings]

FIG. 1 is a schematic piping diagram illustrating a piping configuration of a flux coating device of the present invention.

FIG. 2 is a front view of the coating apparatus main body of the flux coating apparatus of the present invention, illustrating a structure of the coating apparatus main body in a sectional view.

FIG. 3 is a side sectional view of the coating apparatus main body for explaining the structure of the coating apparatus main body of the flux coating apparatus of the present invention.

FIG. 4 is a sectional view of a flux tank and an overflow tank for explaining a liquid level detection sensor provided in the flux tank.

FIG. 5 is a flow chart diagram for explaining a cleaning operation of the ultrasonic coating apparatus of the present invention.

FIG. 6 is a schematic piping diagram for explaining an example of another flux supply means.

[Explanation of symbols]

 1 Flux coating device 2 Coating device main body 5 Conveyor 7 Flux tank 8 Ultrasonic atomizer (sprayer) 11 Supply pipe (flux supply pipe) 16 Discharge pipe 17 Electromagnetic switching valve (switching valve) 21 Flux supply pipe 23 Diluent supply pipe P Printed board

Claims (1)

[Claims] 1. A flux coating apparatus, which is provided in a soldering apparatus and sprays and coats a flux on a lower surface of a printed circuit board conveyed by a conveyor, and a flux tank in which flux is stored and a flux tank in which the flux is stored. A sprayer that sprays the flux, a flux supply pipe that sends the flux to the flux tank, a diluent supply pipe that sends a diluent that dilutes the flux to the flux tank, and the flux supply pipe and the diluent supply pipe are connected. A flux supply pipe, a diluent supply pipe, and a switching valve for selectively switching the respective channels of the flux tank, and a discharge pipe for discharging the solvent stored in the flux tank, The switching valve is configured to spray the diluent by the sprayer. When the flux in the flux tank is discharged by the outlet pipe, the diluent supply pipe and the flux tank are communicated with each other to supply the diluent into the flux tank. ..