JP3513575B2 - Screen cleaning device for screen printing machine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention arranges an object to be printed at a predetermined position on the lower surface of a screen having a plurality of pattern openings.
A screen cleaning device of a screen printing machine, that is, a screen cleaning device that prints a printing material on the substrate through the holes by moving a squeegee on the upper surface of the screen. The present invention relates to a cleaning device for removing a residue of a printing material attached to the upper surface or the lower surface or the opening of a screen.

[0002]

2. Description of the Related Art In screen printing, the higher the viscosity of the printing material used, the more the screen is printed after the printing process is completed, especially on the lower surface of the screen in and around the pattern openings. Material adheres and tends to remain as a residue,
If printing is continued while leaving these residues, printing defects such as bleeding and blurring of printing are caused. Therefore, when a residue is generated, it needs to be removed from the screen.

Previously, the cleaning of the screen was carried out by removing the screen and manually, but after that, a spatula or a scraper blade or the like was screened. It is possible to slide the contact residue with the screen to automatically scrape off the adhered residue, or move the suction nozzle along the bottom surface of the screen to adhere the screen opening or its surrounding area. A method has been proposed in which a residue is peeled off by a vacuum suction action, a method of using them together, and the like.

[0004]

In the scraping method using the spatula or scraper blade, etc., not only is it impossible to remove the residue in the screen opening, but also it is not possible to remove the residue. There are problems that the screen is scratched due to repeated execution of the polishing operation, and that the pattern of the screen opening is easily deformed by rubbing. On the other hand, in the above-described vacuum suction removal method, the suction removal of the residue peeled off or scraped from the screen or the residue with low tackiness that is easily and removably attached to the screen, Like vacuuming a vacuum cleaner to remove dust,
Although it can be performed relatively easily, for example, the viscosity is ≧ 700,000 like a solder paste in which a solder alloy powder and a high-viscosity liquid flux are kneaded to form a cream.
When a high viscosity printing material with cP (centipoise) adheres firmly to the screen as a residue, or when a group of paste solder particles lacking flux due to evaporation etc. become hard -If the residue is tightly adhered to the inner wall of the opening of the nozzle, etc. as a residue, it is effective to remove such residue by vacuum suction so that the binding substances are not It is extremely difficult because it has a poor destructive power to separate into.

The present invention has been made in view of the above-mentioned problems, and makes the screen printing highly efficient, highly accurate, and highly efficient through efficient and effective cleaning of the screen. A screen cleaner suitable for a printing machine capable of increasing the density, especially for a screen printing of solder paste for mounting chip-shaped electronic components on a printed circuit board.
The main purpose is to provide a steering device.

[0006]

In order to achieve the above object, a screen cleaning device according to the present invention is provided with a material to be printed at a predetermined position on the lower surface of a screen having a plurality of pattern openings. In the screen cleaning device of the screen printing machine for printing the printing material on the substrate through the openings by moving a squeegee on the upper surface of the screen. Frames that can move horizontally along the screen are arranged on both upper and lower sides of the screen, and each frame is equipped with a blow-out nozzle for ejecting high-pressure air toward the screen. First clear
The screen is formed by a jet flow from the blowing nozzle at a position spaced apart from the head by a predetermined distance in front of the moving head.
A second cleaning head equipped with an intake nozzle for vacuuming the residue of the printing material adhering to the screen that has been forcibly peeled from the screen, and the first cleaning. A feature is that the head can be moved and displaced in the vertical direction within a predetermined range.

For other structural features of the screen / cleaning device according to the present invention, refer to the description of claims 2 to 6.

[0008]

When high-pressure air is ejected from the blowing nozzle of the first cleaning head toward the screen, the jet collides with one surface of the screen with strong pressure energy, so that the vacuum is generated. A strong impact force, which cannot be obtained from the air flow generated by suction, acts on the collision surface, so that the residue of the printing material adhering thereto is forcibly peeled off and blown off. On the other hand, the residue that has been forcibly peeled off in this way is removed by the second cleaner located at a predetermined distance in front of the moving direction of the first cleaning head.
It is sucked by the suction nozzle of the head and is then sucked and transferred inside. Since the first and second cleaning heads are attached to movable frame bodies respectively arranged on both upper and lower sides of the screen, residues attached to both upper and lower surfaces of the screen are attached. Not only is it possible to remove
It is also possible to efficiently and effectively clean and remove the residue that is stubbornly adhered to the inside of the opening of the nozzle. The remaining operation will be described in detail in the description of the embodiments below.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A screen cleaning apparatus for a screen printing machine according to the present invention will be described in detail below with reference to the drawings showing the embodiments.

FIG. 1 shows an embodiment of the present invention.
A is a squeegee device for screen-printing a solder paste on a printed circuit board (hereinafter, simply referred to as a board) P, 1 is a metal screen having a plurality of pattern openings 1A, 2
Is a pair of first guide rails extending horizontally and in parallel, and the squeegee device A is suspended by the first guide rail 2 via a vertical movement mechanism 3 having an air cylinder. Along the guide rail 2, a belt driving mechanism (not shown) can reciprocate in the front-rear direction.

The squeegee device A is provided with a horizontally long hermetically-sealed housing 5 having an elongated opening / closing opening 4 which can be opened and closed in the transverse direction, and a solder paste S is stored and supplied therein. From the mouth 4 to the upper surface of the screen 1, an appropriate amount of solder paste
Strokes can be automatically supplied. A pair of blades 6A and 6B are provided on the front and rear sides of the supply port 4 so as to hang down, and the rear blades 6B function as squeegees when moving forward. Is configured.

Reference numerals B1 and B2 indicate screen cleaning devices. For convenience, B1 is called an upper cleaning device and B2 is called a lower cleaning device. Reference numeral 7 is a pair of second guide rails that extend horizontally and vertically below the first guide rail 2 and above the screen 2, and the upper cleaning device B1 includes: The second guide rail 7 is suspended via a pair of vertical movement mechanisms 8 equipped with an air cylinder, and the ski is suspended along the guide rail 7.
Belt drive mechanism (not shown), similar to device A
With this, it is possible to move back and forth horizontally in the front-rear direction. Reference numeral 9 is a pair of third guide rails which extend below the screen 1 horizontally and in parallel,
The lower cleaning device B2 is erected on the third guide rail 9 through a pair of vertical movement mechanisms 10 equipped with an air cylinder, and the upper cleaner is installed along the third guide rail 9. As in the case of the steering device B1, a belt driving mechanism (not shown) can be horizontally reciprocated in the front-rear direction.

The upper and lower cleaning devices B1,
B2 includes frame bodies 11 and 12 attached to the vertical movement mechanisms 8 and 10, respectively.
Is equipped with first cleaning nozzles N1 and N2 for ejecting high-pressure air toward the screen 1, respectively.
The heads 13A and 13B and the solder paste attached to the screen, which is forcibly peeled from the screen 1 by the jets from the blowing nozzles N1 and N2, at positions separated by a predetermined distance in front of the heads 13A and 13B. The second cleaning heads 14A and 14B respectively provided with suction nozzles M1 and M2 for vacuum-sucking the residue S1 of the strike are attached.

As can be seen from FIGS. 2 to 4, the blowing nozzle N
1st cleaning head 1 provided with 1 and N2 respectively
3A and 13B are formed as hollow cylindrical bodies having a substantially spiral cross section. As can be seen from FIG. 1, the heads are attached to the frame bodies 11 and 12 so as to be rotatable about a horizontal axis so that the directivity angles of the blowout nozzles N1 and N2 with respect to the screen can be arbitrarily adjusted. And the vertical slots 15 formed at the rear of the frames 11 and 12.
It is attached so that it can be displaced vertically along A and 15B.

The second cleaning heads 14A and 14B having the intake nozzles M1 and M2, respectively, are shown in FIGS.
As can be seen from the above, each of the intake nozzles is provided with elongated intake ports M1 'and M2' which extend in the transverse direction and which are opened rearward and obliquely face the screen 1, respectively. Guide plates 16A and 16B for guiding the jets from the blowout nozzles N1 and N2 to the intake ports are provided around the intake ports M1 'and M2', respectively.

Reference numerals 17A and 17B denote pressurized air supply pipes each having one end connected to another air tank (not shown) connected to a compressor (not shown), and each air supply pipe 17A. , 7B are connected at their other ends to the inlet side of the electromagnetic on-off valves 18A, 18B, and the valves 18A,
Blowing pipes 19A and 19B for blowing pressurized air into the first cleaning heads 13A and 13B, respectively, are connected to the outlet side of 18B.

In FIG. 5, a supply pipe 20 for supplying a solvent is connected to the downstream side of each of the solenoid on-off valves 18A, 18B to connect the solvent with pressurized air to the first cleaning heads 13A, 13B.
It shows a modified example that can be blown into each. In the illustrated example, the solvent supply pipe 20 is
It is connected to the pipe joint 21 of the suction pipes 19A and 19B.
The connection end of the solvent supply pipe 20 may be narrowed like a nozzle so that the solvent can be atomized.

Reference numerals 22A and 22B denote suction hoses 22A and 22B, respectively, one ends of which are connected to the second cleaning heads 14A and 14B, and the other ends thereof are connected to a vacuum pump (not shown). And a filter (not shown), respectively.

Screen screen constructed as described above
In the scanning device, after the printing process of each time or a plurality of times by the squeegee device A of the screen printing machine is completed,
Clean the upper and lower cleaning devices B1 and B2.
The nozzles N1 and N2 are moved in the direction of arrow X shown in FIG.
High-pressure air is ejected from each of the intake nozzles M
When a suction air flow is generated by the nozzles 1 and M2, the residue S'of the solder paste S adhering to the upper surface and / or the lower surface of the screen 1 is discharged from the blowing nozzles N1 and N2 corresponding to the surface. The guide plate 1 is attached to the intake nozzles M1 and M2 located in front of the blowout nozzle while being forcibly separated and blown off by the pressure energy or impact force of the jet flow.
While being guided by 6A and 16B, they are sucked (Fig. 6).
(Refer to FIG. 3), and is sucked into the inside and transferred by the suction hose 22.

Next, when the jets from the blowing nozzles N1 and N2 enter the openings 1A of the screen 1 from both the upper and lower sides of the screen 1, the pressure energies thereof intersect with each other as shown in FIG. Acting in a direction that causes the high pressure air to become stronger than when the high pressure air is ejected from one of the ejection nozzles N1 or N2, and the solder paste is firmly adhered to the inside of the opening 1A.
The strike residue S'is also easily blown off and removed. In this case, a part of the residue S ′ blown off by the jet from the blowing nozzle penetrates the opening 1A and corresponds to the blowing nozzle on the opposite side of the blowing nozzle from the intake nozzle M1 or M.
2 is suctioned off.

If the residue S'of the flux-deficient or dry solder paste is closely packed in the opening 1A of the screen 1 or adheres very firmly,
When it is difficult to easily remove even with the jet flow as described above, the cleaning head 13A, for example, a solvent such as a solution containing a halogenated hydrocarbon as a base, is passed through the solvent supply pipe 20. When injected into 13B and sprayed from the blowing nozzles N1 and N2 in an atomized state, such a stubborn residue is also softened, so that it can be easily removed and cleaned. At that time, if necessary, the position of the cleaning head of the blowing nozzle may be vertically moved and adjusted to adjust it, or the directivity angle of the blowing nozzle may be adjusted.

[0022]

Since the present invention is constructed as described above, it has the following effects.

In the screen cleaning device according to the first or second aspect of the present invention, not only is it possible to remove the residues attached to both the upper and lower surfaces of the screen, but also the screen. It is possible to efficiently and effectively clean and remove the residue firmly adhered to the inside of the holes of the screen, and to improve the efficiency and efficiency of screen printing, especially the screen printing of solder paste on the substrate. Precision and high density can be achieved.

In the screen cleaning device of the fourth aspect, the resistance at the time of jetting the high-pressure air is reduced and the jet velocity thereof is increased, whereby the pressure energy of the jet is increased. In addition, the cleaning effect can be enhanced by appropriately adjusting the directivity angle of the blowout nozzle with respect to the screen according to the adhered state and the adhered amount of the residue.

In the screen cleaning device according to the fifth aspect of the present invention, the electromagnetic opening / closing valve is employed, so that the supply / stop operation of the pressurized air can be performed quickly and reliably.

In the screen / cleaning device according to the sixth aspect, by spraying the solvent, it is possible to easily remove and clean the residue that is extremely stubbornly attached to the openings of the screen. it can.

[Brief description of drawings]

FIG. 1 is a screen of a screen printing machine according to the present invention.
Schematic side view showing an outline of one embodiment of a cleaning device

FIG. 2 is a perspective view showing a main part of the upper cleaning device shown in FIG.

FIG. 3 is a perspective view showing a main part of the lower cleaning device shown in FIG.

FIG. 4 is a cross-sectional view of an outlet nozzle portion of the first cleaning head.

FIG. 5 is a perspective view showing a state in which a solvent supply pipe is connected to a pipe joint of a blow pipe.

FIG. 6 is an explanatory view showing an example of a cleaning work state of the device of the present invention.

FIG. 7 is an explanatory view showing another example of the cleaning work state of the device of the present invention.

[Explanation of symbols]

A squeegee device 1 screen 1A screen opening 6B squeegee N1 blow nozzle N2 blow nozzle M1 intake nozzle M2 intake nozzle 11 frame 12 frame 13A 1st cleaning head 13B 1st cleaning head 14A 2nd cleaning head 14B 2nd cleaning head S solder paste S'Solder paste residue 16A guide plate 16B guide plate 17A air pipe 17B air pipe 18A solenoid valve 18B solenoid valve 19A blow pipe 19B blow pipe 20 Solvent supply pipe 21 pipe fittings

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-7-314653 (JP, A) JP-A-5-318711 (JP, A) JP-A-5-193102 (JP, A) JP-A-6- 126928 (JP, A) JP 5-193124 (JP, A) JP 5-220460 (JP, A) JP 55-2041 (JP, A) Actually developed 63-3445 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) B41F 35/00 B41F 15/12 H05K 3/34 505

Claims (6)

(57) [Claims] 1. A printing material is placed at a predetermined position on a lower surface of a screen having a plurality of pattern openings, and a squeegee is moved on an upper surface of the screen so that a printing material is passed through the openings. In a screen cleaning device of a screen printing machine for printing on the printing material, a frame body which is horizontally movable along the screen is arranged on both upper and lower sides of the screen. In addition, the first cleaning head provided with a blowing nozzle for ejecting high-pressure air toward the screen on each frame and at a position spaced apart by a predetermined distance in front of the moving direction of the cleaning nozzle from the blowing nozzle. A second cleaning head having an intake nozzle for vacuum-sucking the residue of the printing material adhering to the screen that is forcibly separated from the screen by the jet flow of , A screen cleaning device, wherein the first cleaning head is configured to be vertically movable within a predetermined range. 2. A printing material is placed at a predetermined position on the lower surface of a screen having a plurality of pattern openings, and a squeegee is moved on the upper surface of the screen so that the printing material passes through the openings. In a screen cleaning device of a screen printing machine for printing on the printing material, a frame body which is horizontally movable along the screen is arranged on both upper and lower sides of the screen. In addition, the first cleaning head provided with a blowing nozzle for ejecting high-pressure air toward the screen on each frame and at a position spaced apart by a predetermined distance in front of the moving direction of the cleaning nozzle from the blowing nozzle. A second cleaning head having an intake nozzle for vacuum-sucking the residue of the printing material adhering to the screen that is forcibly separated from the screen by the jet flow of , A screen cleaning device, wherein a guide plate for guiding the jet flow from the blowout nozzle to the intake port of the intake nozzle is provided around the intake port of the intake nozzle. 3. The printed material is a printed circuit board, and the printing material is a solder paste prepared by kneading a solder alloy powder and a high-viscosity liquid flux into a cream-like solder paste. Screen cleaning device. 4. A first cleaning head having an intake nozzle is formed as a hollow cylindrical body having a generally spiral shape in cross section, and a horizontal axis line is provided on a frame body so that a directivity angle of the ejection nozzle with respect to a screen can be arbitrarily adjusted. The screen cleaning device according to claim 1 or 2, wherein the screen cleaning device is rotatably mounted around the screen cleaning device. 5. An air supply pipe for pressurized air is connected to the first cleaning head via an electromagnetic on-off valve and a blowing pipe, as claimed in any one of claims 1 to 4. Screen cleaning device. 6. A solvent supply pipe is connected to a blowing pipe for blowing pressurized air into the first cleaning head having a blowing nozzle, and the solvent is atomized to be sprayed on the screen. Claims 1 to 5 characterized
The screen cleaning device according to any one of 1 to 6 above.