JPH0639340A - Applying method for spraying agent - Google Patents

Abstract

PURPOSE:To adjust the applying method of a spraying agent easily and prepare a desired uniformly coated film surely by spray coating the spraying agent entrained and applied on a rotating mesh outer peripheral wall by rotation onto a base face to be coated by the spraying agent by means of upward jetting gas. CONSTITUTION:A rotating cylinder 1 with a mesh outer peripheral wall 2 is placed horizontally in flux liquid F in a flux tank 6 in a manner of immersing the lower section of the cylinder, and an air jetting tube 5 with an upward jet opening is disposed in the rotating cylinder 1. Further, the print bases 8 as bases for applying the spraying agent are operated above the jetting tube 5, and the flux liquid F entrained and applied on the rotating mesh outer peripheral wall 2 by rotation is applied for spray coating the above print bases 8 by the upward jetting gas from the jet opening. A good and stabilized spray coated layer can be applied for coating securely by the arrangement.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating method of various paints and a spraying agent such as a flux applied to a printed circuit board when soldering.

[0002]

2. Description of the Related Art Conventionally, the problems to be solved by the invention
In order to apply various paints, flux for soldering, etc. to the surface of the base material, a method of applying the paint, flux liquid, etc. onto the surface of the base material with a brush or a method of spraying by spraying from a spray nozzle has been adopted. It was For example, (1) foaming type and (2) spray nozzle type are known as means for applying this kind of flux called fluxer used for soldering a printed circuit board. A method of applying flux by immersing a porous hollow cylindrical tube in the interior of the hollow cylindrical tube, supplying air to the hollow cylindrical tube to form a corrugated or chevron shape with foamed particles of flux, and passing a printed circuit board on top of the corrugated shape Is.

Further, (2) the spray nozzle type is one in which flux is applied by spraying nozzles into fine droplets and spraying them onto a printed circuit board. This is because not only the flux liquid does not unnecessarily permeate from the electronic component insertion hole mounted on the board, but also a uniform coating amount can be obtained and adjustment is easy. It is suitable for.

Among those described in the prior art, in the former foaming type, the various sizes of the foam particles of the flux and the corrugations or peaks formed by jetting are not always uniform in height, and the amount of flux applied is too large. At this time, the flux exudes strongly into the insertion holes of various electronic components mounted on the substrate due to the capillary phenomenon, and there is also unnecessary adhesion due to the corrugated or chevron around the edge of the substrate due to the foam particles of the flux,
When the amount of flux is too small, there is a problem that coating unevenness occurs and a constant coating amount cannot be obtained, so that the solderability is deteriorated. Therefore, the foaming type, exudation from the component insertion hole of the printed circuit board, it is not possible to adjust the flux coating amount, it is not possible to obtain a desired flux coating film, the quality of the substrate, performance, etc. is significantly impaired, This had a negative effect on the product value, such as reduced productivity.

Next, the latter spray nozzle type fluxer not only does not cause unnecessary permeation of the flux liquid from the electronic component insertion hole mounted on the printed circuit board, but also provides a uniform coating amount and is easy to adjust. Therefore, it is suitable for soldering of precision electronic equipment, but since the flux liquid for spraying used for coating passes directly through the spray nozzle, the residual flux will remain when the spray nozzle is not used for a long time. Since the flux residue inside the spray nozzle is thawed by the liquid and causes nozzle clogging, the flux residue must be dissolved and removed. Therefore, there is a problem that cleaning of the spray nozzle as maintenance is indispensable. there were.

Further, since the spraying area of the flux by the spray nozzle spreads excessively and is unnecessarily scattered,
Due to the fact that necessary adjustment of the spraying area is required and its handling is difficult, this type of spray nozzle type has a problem that it cannot be incorporated into an automatic soldering device in the integrated processing process of soldering work. there were. Therefore, similar to the foaming type, the flux exudes from the end portion of the printed circuit board and unnecessarily adheres to the product, which adversely affects the commercial value such as deterioration of quality.

The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to control the amount of the spraying agent applied onto the surface of the spraying agent applying base material. An object of the present invention is to provide a method for applying a spraying agent, which can be easily adjusted and can surely obtain a desired uniform coating film.

[0008]

In order to achieve the above-mentioned object, that is, according to the present invention, a rotating cylinder having a mesh outer peripheral wall is laterally arranged so that the lower part is soaked in a spraying agent liquid in a spraying agent tank. Further, in the rotary cylinder, a fumarine pipe having an upward fumarole is disposed, and further, the spraying agent coating base material is fed above the fumarolic pipe to the outer peripheral wall of the rotary mesh. This is a spraying agent application method characterized in that the spraying agent carried and applied by rotation is sprayed onto an upper surface of the spraying agent applying base material by an upward jet gas from a jet port. Further, it is preferable to dispose a spray agent mist width adjusting plate between the rotary cylinder and the spray agent coating base material above.

It is also preferable that the rotary cylinder has a side wall for pivotally attaching the rotary shaft. In particular, it is preferable that the fumarolic pipe has a plurality of fumarolic holes arranged on the upper surface thereof and also serves as a support shaft of the rotary cylinder.

[0010]

The function of the present invention will be described. The rotating cylinder body according to the present invention has a mesh outer peripheral wall, is axially mounted on the side wall of the spray agent tank, and about half of the lower end portion is stored in the spray agent liquid tank. While being immersed in the liquid, the spraying agent liquid is pumped up by the rotation of the rotary drive device, and reaches the upper side while being attached and held as a liquid film on the outer peripheral wall of the mesh.
The mesh outer peripheral wall material used for the rotating cylinder is a stainless mesh as a material that is dense and has corrosion resistance suitable for holding the liquid film of the spraying agent, and is also easy to process. It is desirable to attach a wire, and in this embodiment, for example, a wire diameter of 0.1 to 0.2 mm and a number of 70 to 15
Although it uses a stainless mesh of No. 0, it can be mass-produced at a relatively low cost.

Above the spray agent mist width adjusting plate formed by projecting at the center of the upper surface of the spray agent tank, a spray agent applying base material transferred by a transfer device having a support is attached. When it reaches the predetermined position, it will be automatically or manually
The gas pressure feeding device is activated to energize the gas blow switch,
Gas is ejected toward a preset spray application region above a plurality of fumaroles provided on the upper surface of a fumarolic pipe provided inside the rotary cylinder. The spraying agent mist width adjusting plate is provided with a rectangular gap as the adjusted spray coating area so as to cross the traveling direction of the spraying agent applying base material. The length of the spray coating area can also be adjusted by the rubber plate that is slidable.

Then, the spraying agent liquid film pumped up by the outer peripheral wall of the mesh is blown off as fine droplets by blowing gas from a plurality of upwardly facing fumaroles provided in the fumarolic pipe, and atomized spraying. The agent is applied by spraying on the surface of the base material. The above-mentioned fumaroles of the fumarolic pipe can be arranged in a row, which is suitable for atomizing the spray liquid, for example, has a diameter of 1.0 mm and a pitch of about 3 to 10 mm. Further, it is preferable to use the proximity distance between the mesh outer peripheral wall of the rotary cylinder and the fumarole of the fumarolic tube to be about 5 to 10 mm (this value range is determined by the compressor capacity owned by the user).

The base material for spraying agent is transferred, spraying agent is sprayed while passing through the base material, the operation of the gas pressure feeding device is stopped immediately after passing through the base material, and the coating process is completed. Incidentally, in order to prevent the spraying agent liquid adhering to the rotary cylinder from solidifying, the spraying agent residue can be easily dissolved and removed by simply performing idle rotation before use. Further, since the spraying agent application amount is proportional to the number of rotations of the rotary cylinder, the rotation speed of the rotary cylinder (1 to 23 rotations per minute is preferable).
A coating film having a desired thickness can be obtained by adjusting the above. Further, the application amount can be adjusted by adjusting the output amount of the gas pressure of the gas ejected from the fumarolic pipe.

[0014]

Next, an example of spraying a soldering flux onto a printed circuit board, which is an embodiment of the present invention, will be described with reference to the drawings showing a spraying agent application device. FIG. 1 is a side cross-sectional view of a flux applying apparatus for soldering a printed circuit board of this embodiment, FIG. 2 is a perspective view of the apparatus, and FIG. 3 is a partially cutaway perspective view of a rotary cylinder. 1 and 2
In the embodiment of the printed circuit board soldering flux applicator shown in FIG. 1, the rotary cylinder 1 uses a stainless mesh outer peripheral wall 2 having excellent corrosion resistance, and uses acid-resistant plastics on both side walls 3. And then configured.

In FIG. 3, the rotary shaft of the rotary cylinder 1 is connected to a conduit (not shown) of a gas pressure feeding device, and has a large number of jet holes 4 of the same size so that compression air can be jetted. Thus, the squirt pipe 5 as a support shaft and air supply pipe is formed by arranging one line at equal intervals. The rotary cylinder 1 is mounted on the side wall of a rectangular flux tank 6 so that about one half of the lower end is immersed in the flux liquid F contained in the flux tank, and the rotary drive device (Fig. (Not shown) and rotate. In this embodiment, the number of revolutions is 10 revolutions per minute.

As shown in FIGS. 1 and 2, the flux liquid F
A frame-shaped receiving plate 7 is provided so as to project upward on the peripheral edge of the upper portion of the flux tank 6 for accommodation, and a supporting member for the printed circuit board 8 is provided at the center of the receiving plate 7. A flux mist width adjusting plate is provided by fixing the both ends of two slit plate bodies each having a C shape in a side view so as to cross the traveling direction of the substrate passing therethrough by the provided transfer means 11. It is configured as a frame body in which 9 are integrated. And
A rubber plate 10 is slidably provided on the lower portion of the flux mist width adjusting plate 9 so that the length of the width of the gap can be freely adjusted by a sliding device (not shown).

The mist width adjusting plate 9 of the flux tank 6
Is capable of adjusting the spray application area of the flux liquid according to the size of various printed circuit boards by the sliding device of the rubber plate 10 described above, and by shielding unnecessary portions, the flux liquid of peripheral equipment due to diffusion and scattering of spray. It is possible to prevent dirt and unnecessary consumption of money. In the coating process of the flux liquid F of the embodiment of the present invention, when the printed circuit board 8 is transferred above the flux mist width adjusting plate 9 and positioned in the spray coating area, the above gas pressure feeding device is operated automatically or manually. To do.

The compression air, which is supplied to the fumarolic pipe 5 via the rotary shaft-cumulative air feeding pipe connected to the gas pressure feeding device while the substrate is being transferred or passed, is provided on the upper surface of the fumarolic pipe 5 so as to face upward. The liquid film of the flux liquid F adhering to the rotary cylinder 1 is immediately atomized by the air pressure blown upward from a large number of the air outlets 4. The atomized flux liquid F is sprayed into the spray coating area set by the flux mist width adjusting plate 9 and the rubber plate 10 which prevent diffusion, and is coated on the soldering portion of the substrate.

The blower tube 5 for injecting compression air is formed to have substantially the same length as the rotary cylinder 1. The application by atomization of the flux liquid F is performed from the front in the traveling direction with respect to the printed circuit board 8 transferred into the spray application area, and the operation of the gas pressure feeding device is stopped after passing the substrate to complete the flux application process. To do.

The outer peripheral wall material used for the rotary cylinder 1 is preferably a dense and corrosion-resistant material suitable for holding a liquid film of flux and atomizing it. The outer peripheral wall material of the rotary cylinder 1 shown in the present embodiment is attached using a 100 mesh stainless mesh having a wire diameter of 0.15 mm. The mesh diameter is 0.05 mm to 0.20 mm. Also,
The diameter of the rotary cylinder 1 is 120 mm. Regarding the large number of fumaroles 4 in the fumarole pipe 5, the diameter is 1 m.
m and a pitch of 5 mm are used, and the relationship with the liquid film of the flux liquid F depending on the size of the mesh of the stainless steel mesh may be arbitrarily adjusted as long as they have the same size and equal intervals.

In the above-mentioned embodiment, the soldering flux is spray-coated on the printed circuit board, but the coating material may be spray-coated on various substrates.

[0022]

The method of the present invention is superior to the conventional method.
It has an extremely excellent advantage and has the following effects. The spray agent liquid film is entrained on the outer peripheral wall of the mesh of the rotating cylinder,
Since the liquid film adheres to this liquid film, gas is blown from the fumarole of the fumarolic pipe, atomized, and sprayed onto the base material for spraying agent coating, so that it is applied to the base material for spraying agent coating. As a result, a spray coating layer that is always good and stable can be reliably coated. Therefore, unnecessary bleeding or coating unevenness on the base material for spraying agent application due to an excessive or insufficient amount of spraying agent application does not occur.

The spraying agent applied amount can be arbitrarily and surely applied by adjusting the rotation amount of the rotary cylinder and the gas pressure from the fumarolic pipe. Therefore,
Since this adjustment can be easily performed, a spraying agent film having a desired coating thickness can be formed.

The rotating cylinder is made of a durable material, and by reliable and compact adjustment and stable application means, there is no need for cleaning work with the residue of the spraying agent, so the management of the device is easy. Becomes When the spraying agent is applied, since the spraying agent liquid does not exude on the coating substrate, it is not necessary to wash the substrate with freon or the like, which is a cause of environmental pollution.

[Brief description of drawings]

FIG. 1 is a side sectional view of a flux applying device for soldering a printed circuit board according to an embodiment of the present invention.

FIG. 2 is a perspective view of a flux applying device for soldering a printed circuit board in the present embodiment.

FIG. 3 is a partially cutaway perspective view of a rotary cylinder according to the present embodiment.

[Explanation of symbols]

 1 rotating cylinder 2 mesh outer peripheral wall 3 side wall 4 fumarole 5 fumarole 6 flux tank 7 receiving plate 8 printed circuit board 9 flux mist width adjusting plate 10 rubber plate 11 printed circuit board transfer means F flux liquid

Claims (6)

[Claims] 1. A rotary cylinder having a mesh outer peripheral wall is so arranged as to be immersed in the spray liquid in a spray tank, and the spray cylinder is provided with an upward blowout port. A fumarolic pipe is provided, and a spraying agent coating base material is sent above the fumarolic tube to entrain and spray the spraying agent entrained and applied to the outer peripheral wall of the rotating mesh upward from the fumarole. A method for applying a spraying agent, characterized in that the spraying agent is applied to the upper surface of the spraying agent-applying substrate by spraying. 2. The blowing agent mist width adjusting plate is arranged between the rotary cylinder and the blowing agent applying base material which is fed upward. How to apply the adhesive. 3. The method for applying a spraying agent according to claim 2, wherein the spraying agent mist width adjusting plate is a slit plate. 4. The method for applying a spraying agent according to claim 2, wherein the spraying agent mist width adjusting plate is composed of two plate bodies having a V-shape in a side view. 5. The method for applying a spraying agent according to claim 1, wherein the rotary cylinder has a side wall for pivotally mounting the rotary shaft. 6. The fumarolic pipe has a plurality of fumarolic holes arranged in a row on the upper surface thereof, and also serves as a support shaft of the rotary cylinder. The method for applying a spraying agent according to any one of the above.