JP3400184B2 - Liquid spraying mechanism and flux coating device using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid spraying mechanism utilizing centrifugal force, and a flux coating device for coating a printed wiring board with a flux by using this mechanism.

[0002]

2. Description of the Related Art Conventionally, such flux coating has been
It was carried out by many methods such as so-called foaming method and immersion method. In recent years, due to the requirement for no cleaning after assembling a printed wiring board (hereinafter “board”), flux is applied to the surface of the board to be soldered by using an air spray gun, an airless spray gun, or ultrasonic vibration. The method of spraying the liquid was adopted.

[0003]

However, the above-mentioned air spray gun and airless spray gun have complicated mechanisms and are expensive, and maintenance is not easy. In addition, in its operation, a large amount of flux is consumed with a large amount of air, and since the radiation angle from the nozzle is large, the scattering rate to other than the object to be coated is large, and the coating efficiency is poor, and the work is also difficult. There were also environmental problems. On the contrary, in order to prevent this, when spraying in a state where the emission angle from the nozzle is made small and converged, this time the coating range becomes narrow and the work efficiency deteriorates, and flux is required. There is a drawback that it is difficult to apply the minimum amount uniformly.

Further, in the case of using ultrasonic vibration, in addition to the drawback that the device is expensive, maintenance is not easy as in the case of the above, and in addition to the case of the air spray gun, it is possible to place it in a place other than the target. The work efficiency and work environment were deteriorated due to the flux scattering.

Further, as common to the above, there is also a problem that a dust collector for collecting scattered flux must be installed for the purpose of cleaning the working atmosphere.

Therefore, the present invention has been made by paying attention to these problems, and its purpose is to provide a new and advanced liquid sprayer which can efficiently apply the flux by a simple mechanism and does not harm the working environment. A mechanism and a flux coating device using the same are provided.

In order to achieve the above object, the liquid spraying mechanism of the present invention has a large number of perforations or recesses formed on its surface.
A large number of perforations and recesses are formed on the surface of the disk, and the disk is a plate-like disk that is axially rotated by the drive means. The disk is arranged on one or both surfaces of the disk and surrounds the center axis of rotation. And a ring-shaped gutter attached with the convex side facing the outer peripheral edge, a plurality of discharge ports penetratingly opened in the outer peripheral part of the ring-shaped gutter at appropriate intervals, and liquid from the outside in the gutter. And a supply pipe for supplying.

The liquid spraying mechanism of the present invention using the liquid spraying mechanism includes a liquid spraying mechanism according to claim 1 housed in a shell-shaped case, and a radial direction of a disk of the liquid spraying mechanism. As described above, the coating port is formed on the surface of the case, and the moving means for moving the substrate to be coated while covering the coating port with the surface to be coated.

Further, it is characterized in that the flux stored in the bottom of the case is returned to the supply pipe by the pump means and circulated.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an example of a concrete embodiment of a liquid spraying mechanism and a flux applying apparatus using the same according to the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a perspective view showing an embodiment of a liquid spraying mechanism, FIG. 2 is a partially cutaway perspective view of an embodiment of a flux applying apparatus using the same, and FIG. 3 is a view showing the apparatus. It is the schematic which showed the operation | movement by the partial longitudinal cross-sectional view.

[Structure of Embodiment of Liquid Spraying Mechanism] As shown in FIG. 1, the liquid spraying mechanism 1 has a large number of perforations 2, 2, ... A flat disk 4 is connected to the drive shaft 3 of the drive means (not shown in FIG. 1) and supported rotatably (arrow a). And, on the surface of one side of the disk 4,
The convex portion 5 is formed so as to surround the rotation center axis C.
A ring-shaped gutter 5 with the a side facing the outer peripheral edge 4e of the disk is integrally attached.

In this embodiment, the outer diameter of the ring-shaped gutter 5 (φ
= 40 mm) is set to about half the outer diameter (φ = 80 mm) of the disk 4 and attached. The outer diameter of the ring-shaped gutter 5 is not limited to this.

On the bottom side of the ring-shaped gutter 5, in other words, on the outer peripheral portion of the convex portion 5a directed toward the disk outer peripheral edge 4e side, a plurality of discharge ports 6, 6, ... Are provided at appropriate intervals. It is opened through. The opening of the discharge port 6 is preferably formed so as to be substantially continuous with the surface of the disc 4.

Further, in the front opening 5h of the ring-shaped gutter 5, a nozzle 7a of a supply pipe 7 for supplying a liquid (for example, a flux liquid) into the gutter from the outside is arranged so as to face adjacently. .

In this embodiment, a large number of perforations 2 that penetrate the disk 4 are formed, but in addition to this, a circular recess that does not penetrate may be formed. You may arrange in combination.

Further, the formation positions of these perforations 2 are formed between the ring-shaped gutter 5 and the outer peripheral edge 4e of the disk 4 in FIG. 1 (herein referred to as "diffusion surface 8"). It may be formed on the front surface of the disk 4 in consideration of the simplicity of the above and the air flowability into the gutter 5.

Further, in this embodiment, the ring-shaped gutter 5 is attached only to one side of the disk 4, but it may be provided to both sides.

[Operation of Liquid Dispersing Mechanism] With the above configuration, the disk 4 and the ring-shaped gutter 5 are integrally rotated at a predetermined speed (1700 rpm in this embodiment) (arrow a). In such an operation, the supply pipe 7 supplies a predetermined liquid into the ring-shaped gutter 5 from its nozzle 7a without rotating (arrow b). The supplied liquid is attached to the bottom of the gutter 5 by centrifugal force and is discharged from the discharge port 6 to the diffusion surface 8 on the surface of the disk 4 (arrow c).

The discharged liquid is moved toward the outer peripheral edge 4e along the diffusion surface 8 by the centrifugal force, and at the same time, it is diffused after being made into small particles by the large number of perforations 2, 2 ,. It Then, the liquid particles that have been made into small particles are atomized and separated from the outer peripheral edge 4e, and are sprayed in a parabolic arc in the substantially radial direction of rotation (arrow d).

[Embodiment Configuration of Flux Coating Device] Next, an embodiment of a flux coating device in which the above liquid spraying mechanism is applied to the flux coating on a printed circuit board will be described.

In the flux coating apparatus 10 of this embodiment, first, the entire liquid spraying mechanism 1 is housed in a shell-shaped case 11 having a substantially rectangular box shape. And case 11
In the upper part 11u of the so as to include the radial direction of the rotating disk,
In other words, a substantially rectangular strip-shaped coating port 12 extending in the direction perpendicular to the rotation axis on the rotation surface is provided. Also, the bottom 1
A substantially funnel-shaped liquid reservoir 13 is integrally formed with 1d. Further, a drain pipe 14 is attached to the liquid pool 13.

Next, on the outer surface on one side of the case 11,
An electric motor 15 for rotating the disk 4 of the liquid spraying mechanism 1 is arranged and a drive shaft 3 thereof is arranged to penetrate therethrough, and a supply pipe 7 is arranged to penetrate through the outer surface on the other side. The supply pipe 7 is connected via a pump means 16 to a flux liquid reservoir 17 and also to the drain pipe 14.

Further, in the vicinity of the application port 12, the application port 12
A moving means is arranged to move the printed circuit board 18 while covering the coated surface with the coated surface. The specific mechanism of the moving means is not shown in the drawings because it is not the gist of the present invention, but a conventional general belt conveyor or suspension moving mechanism is used.

In the present embodiment, the coating port 12 is formed on the upper surface of the case, but the present invention is not limited to this, and if the direction includes the radial direction of the rotating disk, the side surface of the case or the diagonal It may be the upper surface.

[Operation of the Flux Coating Device Embodiment] With the above-mentioned structure, the disk 4 is rotated (arrow a) by the start of the electric motor 15, and the flux liquid is supplied by the operation of the pump means 16. When the liquid 7 is supplied from the nozzle 7a of No. 7 into the ring-shaped gutter 5,
By the action of, the flux liquid is scattered from the outer peripheral edge 4e of the disk 4 (arrow d). The scattered small particles of the flux liquid reach the narrow band-shaped range A along the coating port 12 substantially uniformly. In this embodiment, the rotation center axis C is 1
The width of the range A was 3 mm as narrow as 20 mm apart.

As a result, by moving the coated surface of the printed circuit board 18 in one direction or in the reciprocating direction so as to cover the coating port 12 (arrow e), the flux liquid adheres to the coated surface substantially uniformly. It will be.

The flux liquid that has not adhered here, or the flux liquid that is blocked by the inner surface of the case 11 without going to the coating port 12 is collected and collected in the liquid reservoir 13 of the bottom portion 11d. The recovered flux liquid is sent to the pump means 16 via the drain pipe 14 (arrow f), is sent again to the supply pipe 7 and is circulated and reused (14 → arrow f1).
6 → arrow b → 7).

[0029]

[Effects] Since the present invention is configured as described above,
The following effects are achieved. Since the centrifugal force is used, it can be sufficiently scattered even when rotated at a relatively low speed, and there is an effect that only an electric motor for rotating a disk is required as a power source. Since it is moved along the diffusion surface of the disk and scattered from the outer peripheral edge, the scattering width can be made into a narrow band shape, and if the printed circuit board is moved in this width direction, it will be efficient. There is an effect that can be applied. Since perforations or recesses are formed on the diffusion surface of the disk,
The flux liquid is made into fine particles while moving there, and can be atomized into finer particles and scattered or scattered. Since the liquid spraying mechanism is housed in the case, it is possible to prevent the liquid other than the coating object from scattering, and it is possible to collect the flux liquid that has not been coated and reuse it. Further, since the structure is simple, there is an advantage that not only can it be manufactured at low cost, but also maintenance maintenance is easy.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a liquid spraying mechanism.

FIG. 2 is a perspective view showing an example of a flux applying device with a part thereof cut away.

FIG. 3 is a schematic view showing a partial vertical cross-sectional view of the operation of the embodiment of the flux coating device.

[Explanation of symbols]

1 ... Liquid spraying device 2 ... Perforation
3 ... Drive shaft 4 ... Disk 5 ... Ring-shaped gutter
6 ... Discharge port 7 ... Supply pipe 7a ... Nozzle
8 ... Diffusing surface 10 ... Flux coating device 11 ... Case
12 ... Application port 13 ... Liquid pool 14 ... Drain pipe
15 ... Electric motor 16 ... Pump means 17 ... Reservoir source
18 ... Printed circuit board

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI B05D 7/14 B05D 7/14 Q B23K 3/00 B23K 3/00 S H05K 3/34 503 H05K 3/34 503B (58) Survey Fields (Int.Cl. ⁷ , DB name) B05B 3/00-3/18 B05C 9/02 B05D 7/00-7/26 B23K 3/00 H05K 3/34

Claims (3)

(57) [Claims] 1. A large number of perforations in the surface (2, 2,...) The
Is formed with recesses or has a large number of perforations (2,
2, ...) and a concave portion are formed in combination, and the flat plate-shaped disc (4) is axially rotated by the driving means (15), and the disc (4) is arranged on one surface side or both surface sides of the disk (4). A ring-shaped gutter (5) mounted so as to surround the rotation center axis (C) and with the convex part (5a) side facing the outer peripheral edge (4e), and an outer peripheral part of the ring-shaped gutter (5). A liquid spraying mechanism comprising a plurality of discharge ports (6, 6, ...), which are opened through at appropriate intervals, and a supply pipe (7) for supplying a liquid into the trough from the outside. . 2. The liquid spraying mechanism (1) according to claim 1 housed in a shell-shaped case (11), and the disk (4) of the liquid spraying mechanism (1) in a radial direction. A coating port (12) formed on the surface of the case (11), and a moving means for moving the substrate (18) to be coated while covering the coating port (12) with the surface to be coated. Flux applicator. 3. The flux accumulated in the bottom of the case (11) is supplied again by the pump means (16) to the supply pipe (7).
The liquid application device according to claim 2, wherein the liquid application device is returned to and circulated.