JPH01186267A - Method and device for coating flux - Google Patents

Abstract

PURPOSE:To eliminate the unevenness in coating a flux by flowing out a foaming flux in the direction opposing to the progressing direction of a work in the state of no work in the method coating the flux foamed by bubbles on the work from the orifice upper end opening. CONSTITUTION:A foaming cylinder 23 is dipped in the flux 22 of the inner part of a tank 21 and an orifice 24 is provided on the upper side. The upper end opening 26 of the orifice has an oblique section similarly to the transfer route 25 of the work W transferred on the orifice 24. In the state of no work a foaming flux 22a is flowed out in the direction opposite to the work progressing direction. In case of the work W passing through the foaming flux 22a is pulled in the work progressing direction by its contact with the work W, but at the work passing time it is shunted in not only the work progressing direction but also the opposite direction. The foaming flux of either flow is coated to all the corners of the work and the flux coating unevenness on the work can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a flux coating method and a flux coating device using foaming flux.

(Prior art) As shown in FIG.
A porous (unglazed) foam tube 13 is immersed in flux 12 housed inside the tube 1, and an orifice 14 is provided above the pick-up portion 13.

Then, compressed air is supplied to the inside of the foam tube 13, and the flux 12a foamed by the bubbles ejected from the foam tube 13 flows out from the upper end opening 15 of the orifice 14 and is applied to the printed wiring board W as a workpiece. be done.

(Problem to be Solved by the Invention) In such a foaming type flux coating device, the substrate W
When the transport becomes high speed (2.5 m/min or more), the foamed flux is pulled by the board mounting parts etc. due to the contact resistance with the board W, and flows only toward the board advancing side from the orifice 14.

As a result, as shown in FIG. 6, flux may not be applied to a portion 16 of the chip component W2 bonded to the lower surface of the substrate W1, resulting in a problem of uneven flux application.

An object of the present invention is to eliminate uneven flux application to the workpiece.

[Structure of the Invention] (Means for Solving One Problem) The invention described in claim 1 is characterized in that the flux 22a foamed by the bubbles ejected from the foaming tube 23 flows through the orifice 2.
In the flux application method, the foamed flux 22a flows out from the upper end opening 26 of 4 and is applied to the workpiece W transported on this orifice, in which the foamed flux 22a flows out in a direction opposite to the workpiece traveling direction in a state where there is no workpiece. It's a method.

In the invention described in claim 2, an orifice 24 is provided on the upper side of the foam tube 23 immersed in the flux 22,
In the flux coating device, the flux 22a foamed by air bubbles ejected from the foam tube 23 flows out from the upper end opening 26 of the orifice 24 and is applied to the workpiece W conveyed on the orifice 24.
This is a flux coating device in which the upper end opening 26 is formed in an inclined shape downward in the direction opposite to the direction in which the work progresses.

According to a third aspect of the invention, in the flux coating apparatus according to the second aspect, instead of forming the upper end opening 26 of the orifice 24 in an inclined shape, the orifice 24
It is tilted in the direction opposite to the direction in which the work progresses.

The invention described in claim 4 is the flux coating device according to claim 3, in which the inclination angle of the orifice 24 is provided to be variably adjustable.

(Function) The invention according to claim 1 provides foamed flux 22a that is flowed out in a direction opposite to the direction of movement of the workpiece in a state where there is no workpiece.
When passing through the workpiece, the foam flux 22a is pulled in the workpiece progressing direction by contact with the workpiece W, but since it flows not only in the workpiece progressing direction but also in the opposite direction, the foamed flux 22a flowing in either direction reaches every corner of the workpiece. Contact.

In the invention as claimed in claim 2, even if the orifice 24 is vertical, the cut of the upper end opening 26 is oblique, so that the foamed flux 22a flows from the higher end of the upper end opening 26 to the lower end.
flow occurs, and when there is no workpiece, the foaming flux 2
2a is flowed out in a direction opposite to the direction in which the work progresses.

In the invention as claimed in claim 3, since the orifice 24 itself is inclined, the foamed flux 22a rising in the orifice has momentum to flow out in the direction opposite to the direction in which the workpiece advances, and when there is no workpiece, the foamed flux 22a 22a
is flowed in that direction.

In the fourth aspect of the present invention, the optimum inclination angle of the orifice 24 is selected depending on the workpiece conveyance speed, workpiece conveyance angle, workpiece conditions, and the like.

(Examples) Hereinafter, the present invention will be explained in detail with reference to each example shown in FIGS. 1 to 4.

1 and 2 show a first embodiment of the present invention, in which a porous (unglazed) foam cylinder 23 is immersed in a flux 22 housed inside a tank 21. An orifice 24 is provided above.

Similar to the conveyance path 25 of the work W conveyed on this orifice 24, the upper end opening 26 of the orifice is formed in an oblique cut. That is, this upper end opening 26 is formed in an inclined shape that descends in a direction opposite to the direction in which the work progresses.

In this way, since the cut of the upper end opening 26 of the orifice 24 is oblique, the foamed flux 22a flows from the higher end of the upper end opening 26 to the lower end, and when there is no workpiece W, the foamed flux 22a flows in the workpiece traveling direction. It flows out in the opposite direction.

Then, compressed air is supplied to the inside of the foaming tube 23, and the flux 22a foamed by the bubbles ejected from the foaming tube 23 flows from the upper end opening 26 of the orifice 24, which has an oblique cut, as shown in FIG. It flows out in a direction opposite to the direction in which the work travels without any work, as shown in FIG. When passing through the workpiece, the foamed flux 22a is pulled in the workpiece progressing direction due to contact with the workpiece W, but originally the foamed flux 22a
As shown in the figure, since the flow is flowing in the opposite direction to the work progressing direction, when the work passes, the flow is diverted not only in the work progress direction but also in the opposite direction as shown in FIG. Then, the foamed flux flowing in either direction is applied to every corner of the work W (printed wiring board and parts mounted on the board).

FIG. 3 shows a second embodiment of the present invention, in which the entire orifice 24 in the flux applicator is inclined in the direction opposite to the direction in which the work progresses. As a result, the upper end opening 26 of this orifice 24 is also inclined. θ is the inclination angle of the orifice 24.

Since the orifice 24 itself is inclined, the foamed flux 22a rising through the orifice has a force that flows out in the direction opposite to the direction in which the workpiece advances, and when there is no workpiece, it is shown in FIG. The foamed flux 22a is flowed out in the direction opposite to the direction in which the workpiece advances.

FIG. 4 shows a third embodiment of the present invention, which is a flux coating device in which the inclination angle θ of the orifice 24 shown in FIG. 3 is variably adjustable.

That is, a rotation support shaft 31 is integrally provided on both the left and right sides of this orifice 24, and this rotation support shaft 31 is connected to the tank 21.
The rotation support shaft 31 is rotatably fitted into a bearing portion 33 provided on a pair of left and right support plates 32 erected on the bottom surface of the rotor, and is fixed by a screw 34 screwed into the bearing portion 33. It is something that

Since the optimal inclination angle θ of the orifice 24 varies depending on the workpiece conveyance speed (conveyor speed), workpiece conveyance angle (conveyor angle), workpiece conditions (board mounting component density, etc.), each of the above conditions may be changed. When
The inclination angle θ of the orifice 24 is adjusted to the optimum value by loosening the screw 34 and adjusting the rotation of the orifice 24 about the support shaft 31, and then tightening the screw 34.

Note that instead of tilting this orifice 24,
The entire tank 21 may be tilted, but if the entire tank is tilted, it will be difficult to attach the flux specific gravity sensor attached to the tank 21, so it is preferable to tilt only the orifice 24.

〔Effect of the invention〕

According to the invention described in claim 1, since the foamed flux flows out in the direction opposite to the direction in which the work progresses when there is no work, the foamed flux contacts the work and prevents the progress of the work when the work passes. However, since the foamed flux flows not only in the direction in which the work progresses but also in the opposite direction, the foamed flux flowing in either direction is applied to every corner of the work, thereby preventing uneven flux application to the work.

According to the invention described in claim 2, the flux application method described in claim 1 can be easily performed by using the flux application device in which the upper end opening of the orifice is formed in an inclined shape downward in the direction opposite to the direction in which the work progresses. It can be implemented.

According to the invention described in claim 3, the flux application method described in claim 1 can be easily carried out using the flux application device in which the orifice itself is inclined in the direction opposite to the direction of movement of the workpiece.

According to the invention described in claim 4, since the inclination angle of the orifice is provided to be variably adjustable, the workpiece conveyance speed,
Flux application can be performed by adjusting the orifice to an optimal inclination angle depending on the workpiece conveyance angle, workpiece conditions, etc.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a first embodiment of the flux application method and apparatus of the present invention, FIG. 2 is a sectional view when the workpiece passes through the workpiece, and FIG. 3 is a sectional view showing a second embodiment of the present invention. , FIG. 4 is a sectional view showing a third embodiment of the present invention, FIG. 5 is a sectional view showing a conventional flux application method, and FIG. 6 is a sectional view of a workpiece being fluxed by conventional method II. . W... Work, 22... Flux, 22a... Foaming flux, 23... Foaming tube, 24... Orifice, 2
6...Top opening. sleeping ζ base

Claims (4)

[Claims] (1) In the flux application method, the foamed flux is discharged from the upper end opening of an orifice and is applied to the workpiece being conveyed on the orifice. A flux application method characterized by flowing out in a direction opposite to the direction of flux. (2) An orifice is provided on the upper side of the foam tube that is immersed in the flux, and the flux foamed by air bubbles ejected from the foam tube flows out from the upper end opening of the orifice.
A flux coating device for applying flux to a workpiece conveyed on the orifice, wherein an upper end opening of the orifice is formed in an inclined shape that descends in a direction opposite to the workpiece traveling direction. (3) An orifice is provided on the upper side of the foam tube that is immersed in the flux, and the flux foamed by air bubbles ejected from the foam tube flows out from the upper end opening of the orifice.
A flux coating device that applies flux to a workpiece conveyed on this orifice, wherein the orifice itself is inclined in a direction opposite to the direction in which the workpiece travels. (4) The flux coating device according to claim 3, wherein the inclination angle of the orifice is variably adjustable.