JP2003260781A - Screen printing press and cleaning method for screen printing press - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a screen printing press so designed as to be cleaned fully automatically as to the solder paste getting around to the lower side of a screen, without wiping it off by the manual work of an operator, in regard to the screen printing press wherein the solder paste is printed on the surface of a circuit board through openings of the screen with a squeegee slid on the screen. <P>SOLUTION: A suction cleaning means 66 equipped with a suction roll 69 and an ultrasonic cleaning means 75 equipped with a cleaning head having an ultrasonic vibrator 78 are provided on a first carriage 65 moving by guide rails 11 and 12 along the lower side of the screen 25, while a dry-wiping cleaning means 85 is provided, together with a camera unit 14, on a carriage 13. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screen printing apparatus and a method for cleaning the screen printing apparatus,
Particularly, the present invention relates to a screen printing apparatus and a cleaning method for the screen printing apparatus, in which a work is superposed on the lower surface of the screen to print a paste-like substance on the surface of the work.

[0002]

2. Description of the Related Art An electronic circuit device is assembled by mounting electronic parts on a circuit board. Here, a substrate made of an insulating material is used as the circuit substrate. A copper foil is bonded to the surface of the substrate, and a predetermined wiring pattern is formed by etching. Then, the electronic component is mounted thereon, and the electrodes and terminals of the electronic component are soldered to the connection lands of the wiring pattern of the circuit board.

Cream solder is used for soldering the electrodes of the electronic component and the connecting lands of the circuit board as described above. That is, cream solder is printed and attached by a screen printing method at a predetermined position on the surface of a circuit board on which wiring is provided. Then, the electronic component is mounted in a state of being positioned thereon. Then, the circuit board on which the electronic parts are mounted is gently introduced into the reflow furnace. The cream solder is melted by the heat in the reflow furnace, so that the electrodes of the electronic component are soldered to the connection lands of the circuit board. Therefore, when manufacturing an electronic circuit, a screen printing apparatus is required for applying the cream solder to the circuit board by the screen printing method.

Generally, a screen printing apparatus is an apparatus for printing cream solder on a land of a substrate through a pattern of holes provided in the screen, and requires the following unit. That is, a squeegee unit for pushing cream solder into the pattern of the screen, a cleaning unit for cleaning the cream solder remaining on the back side of the screen and the pattern, a camera unit for recognizing the position of the board by detecting alignment marks provided on the board, It is composed of a positioning table and the like for fixing the substrate on which the printing is performed and fixing the substrate in the X-axis direction, the Y-axis direction, the Z-axis direction, and the θ-axis direction.
The present application relates to an improvement of a screen printing apparatus suitably applied to such a cream solder printing machine.

[0005]

When cream solder printing is performed using such a screen printing apparatus,
When the number of times of printing is repeated, cream solder gradually adheres to the opening and the back surface of the screen. If such a quantity of cream solder adheres, good printing cannot be performed, so
In order to prevent this problem, it has been proposed to provide a cleaning paper composed of roll paper and press the cleaning paper against the lower surface of the screen for cleaning.

However, with the conventional cleaning method using such a cleaning paper, it is difficult to completely clean the back surface of the screen to a good state, and a small amount of cream solder often remains. Therefore, it is necessary for the operator to manually wipe the lower surface of the screen every time cleaning is performed or after cleaning is performed a plurality of times.
Such a screen printing device is an obstacle to achieving skilllessness. Further, if a certain amount of cream solder adheres to the lower surface of the screen, good printing cannot be performed. That is, the cream solder wraps around between the substrate and the screen during printing, and printing defects such as chipping or cracking of the printed cream solder occur.

The present invention has been made in view of the above problems, and it is possible to more completely clean the lower surface of the screen and also to completely eliminate the manual cleaning work. An object is to provide an apparatus and a cleaning method thereof.

[0008]

The main invention of the present application is to superimpose a work on a predetermined position on the lower surface of a screen and print a paste-like substance on the surface of the work through an opening of the screen. In such a screen printing apparatus, suction cleaning means for sucking and cleaning the lower surface of the screen using a cleaning cloth, and ultrasonic cleaning means for performing wet cleaning of the lower surface of the screen by vibration of an ultrasonic transducer And a dry wiping cleaning means for wiping the lower surface of the screen with a dry cloth.

Here, the suction cleaning means comprises a supply roll, a take-up roll and a suction roll, roll paper constituting a cleaning cloth is supplied from the supply roll, and the roll paper is wound around the suction roll. It is preferable that the lower surface of the screen is cleaned by sucking with the suction roller and the cleaned roll paper is wound by a winding roller. Further, the suction roll is made of a hollow pipe, a slit is formed on the bus bar so as to face the lower surface of the screen, and the inside is vacuum sucked to suck the lower surface of the screen through the roll paper for cleaning. Is preferred. Further, the suction cleaning means may be arranged so as to extend in a direction orthogonal to the sliding direction of the squeegee that slides on the screen, and be movable in the moving direction and the height direction of the squeegee.

Further, the ultrasonic cleaning means has a ring-shaped member impregnated with a cleaning liquid, the ultrasonic vibrator is arranged at the center of the ring-shaped member, and the ring-shaped member moves in the height direction. It is preferable that it is possible and can be moved close to and away from the screen. Further, the ultrasonic cleaning means includes a supply means for supplying a cleaning liquid to the cleaning head when the cleaning head including the ultrasonic vibrator and the ring-shaped member is in a standby position, and the cleaning head is further provided. Preferably has a lid that prevents evaporation of the cleaning liquid. Further, the ultrasonic cleaning means is a sliding direction of a squeegee sliding on the screen,
The squeegee may be configured to be movable in a lateral direction perpendicular to the sliding direction and in a height direction.

The dry-wiping cleaning means may be composed of a dry-wiping cleaning cloth or a sponge and supported by a supporting member. Further, it is preferable that the dry-wiping cleaning means is configured to be movable in a sliding direction of the squeegee sliding on the screen, a lateral direction perpendicular to the moving direction of the squeegee, and a height direction. The work may be a circuit board and the paste-like substance may be cream solder.

The main invention relating to the cleaning method is
In a screen printing apparatus, which is a lower surface of the screen, is overlapped with a work at a predetermined position, and a paste-like substance is printed on the surface of the work through an opening of the screen, the screen through a cleaning cloth. Suction cleaning means for sucking and cleaning the lower surface of the screen, ultrasonic cleaning means for wet-cleaning the lower surface of the screen by vibration of an ultrasonic transducer, and dry-wiping cleaning means for dry-wiping the lower surface of the screen. Then, any one kind or two or more kinds among the three kinds of cleaning means is selected to clean the paste-like substance adhered to the lower surface and the opening of the screen, and a cleaning method for a screen printing apparatus. It is about.

Here, it is preferable to clean the lower surface of the screen in the order of ultrasonic cleaning, suction cleaning, dry wiping cleaning, or suction cleaning, ultrasonic cleaning, dry wiping cleaning in this order. The work may be a circuit board and the paste-like substance may be cream solder.

A preferred embodiment of the invention included in the present application is a screen of a screen printing apparatus in which a circuit board is fixed at a predetermined position on the lower surface of the screen and cream solder is printed on the surface of the circuit board. Regarding cleaning of the opening and the back surface of the screen, suction cleaning means for sucking through a cleaning cloth,
The screen printing apparatus includes an ultrasonic cleaning unit that uses ultrasonic waves in a wet type and a dry-wiping cleaning unit that performs dry-wiping in a dry type.

In such a screen printing apparatus, the suction cleaning means uses roll paper as a cleaning cloth, and comprises a supply roll, a winding roll and a suction roll, and the roll paper is wound around the suction roll for suction cleaning. . Further, in such a suction cleaning means, the suction roll is a pipe having a hollow cross section, and the suction holes are slits formed on the cylindrical surface in the length direction thereof. Further, such a suction cleaning means arranges the three rolls in a direction perpendicular to the moving direction of the squeegee, and makes the whole of the three rolls movable in the moving direction and the height direction of the squeegee.

In the ultrasonic cleaning means, an ultrasonic vibrator is arranged in the central portion, and a ring-shaped cloth or sponge which can be impregnated with a solvent is arranged so as to surround the ultrasonic vibrator. It can be moved vertically. Further, in the ultrasonic cleaning means, a cleaning head including an ultrasonic vibrator and a ring is provided with a solvent supply means for supplying a solvent at a standby position, and a lid body for preventing evaporation of the solvent is provided. Further, such an ultrasonic cleaning means is configured to be movable on the lower surface of the screen in a moving direction of the squeegee, a lateral direction perpendicular to the moving direction, and a height direction.

Further, the dry-wiping cleaning means comprises a cleaning head composed of a cleaning cloth or sponge, which is movable in the moving direction of the squeegee, in the lateral direction perpendicular thereto, and in the height direction.

In the screen printing apparatus equipped with such suction cleaning means, ultrasonic cleaning means, and dry-wiping cleaning means, the cleaning operation is performed in the order of ultrasonic cleaning, suction cleaning, dry-wiping cleaning, or suction cleaning, ultrasonic cleaning, Clean the bottom of the screen in the order of dry wipe cleaning. Alternatively, any one or more of the suction cleaning means, the ultrasonic cleaning means, and the dry-wiping cleaning means can be selected and used.

According to the screen printing apparatus including the suction cleaning means, the ultrasonic cleaning means, and the dry-wiping cleaning means, a high cleaning effect can be obtained by combining these cleaning means. Therefore, it becomes possible for the operator to omit the work of wiping the back surface of the screen at a predetermined time interval, and the skilllessness can be achieved by completely automating the cleaning. Further, when the three cleaning methods are configured to be used separately and independently, three cleaning means are used together depending on the condition of the degree of dirt on the lower surface of the screen, and any one of them is used alone. Alternatively, it is possible to flexibly deal with using two kinds of cleaning means in combination.

Further, in the screen printing apparatus as described above, since the suction hole of the suction pipe of the suction cleaning means is composed of the slit extending in the length direction of the suction pipe, high suction efficiency can be obtained. Further, by disposing a wet ring impregnated with the cleaning liquid around the ultrasonic vibrator constituting the ultrasonic cleaning means, a high ultrasonic cleaning effect is exhibited. In addition, by using dry wiping cleaning together, it becomes possible to select the optimum cleaning conditions for the screen dirt.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION The screen printing apparatus according to the present embodiment is configured to squeeze an adhesive substance such as cream solder on the screen so that the screen printing device is brought into close contact with the screen at a predetermined position through an opening provided in the screen. In a screen printing machine that prints the cream solder on a work such as a circuit board, the screen is cleaned by a cleaning unit every time a predetermined number of times of printing is performed. Here, as the cleaning means, three kinds of cleaning means, that is, a suction cleaning means, an ultrasonic cleaning means, and a dry-wiping cleaning means are provided.

The suction cleaning means is to install a roll paper under the screen. The unused portion of the roll paper is wound around the supply roll, and the roll paper supplied from the supply roll is wound around the suction roll at a predetermined angle and then wound up by the winding roll. A motor is used as a drive source for the rotation of the take-up roll, whereas the supply roll and the suction roll do not directly have a drive source for rotation, and they are rotated by the tension of the roll paper given by the take-up roll. Roll paper is supplied.

The suction roll is formed by processing a pipe having a circular cross section, and is pressed against the screen through a cleaning paper composed of roll paper. The suction part of the cleaning roll is composed of a slit having a length slightly longer than the opening part of the screen, and the cleaning roll is connected to a vacuum suction device, whereby the inside of the cleaning roll becomes a negative pressure and Suction is performed through the cleaning paper. The used cleaning paper is sequentially wound by the winding roll.

Further, the supply roll and the take-up roll can be easily attached and detached, thereby improving workability at the time of replacement. It should be noted that it is cost effective to wind up the cleaning paper a little for each cleaning and stop the cleaning paper when a clean surface comes out. Note that, instead of such a configuration, the winding may be slowly performed during the cleaning. The supply roll, the take-up roll, and the suction roll are integrated and mounted on a table that can be moved up and down.

Next, the ultrasonic cleaning means will be described. The ultrasonic cleaning means is a cleaning head using an ultrasonic vibrator, and is installed below the screen with the vibrating surface of the ultrasonic vibrator facing the lower surface of the screen. Such an ultrasonic transducer is arranged in the hole portion of the ring-shaped member. The ring-shaped member is configured to be movable up and down by a spring, and when the ultrasonic transducer contacts the screen surface, the ring-shaped member is equalized on the screen.

The above-mentioned ring-shaped member is for making the ultrasonic vibrator usable in a wet state, and is impregnated with a solvent in advance. The cleaning head including the ultrasonic vibrator and the ring-shaped member receives the supply of the solvent from the separately provided solvent supply means during the standby at the standby position. At the standby position, the upper part is closed by a lid to prevent evaporation of the solvent impregnated in the cleaning member.
Such a cleaning head has an X-axis direction, a Y-axis direction,
And is movable in the Z-axis direction, and is pressed against the screen by a predetermined force by the movement operation in the Z-axis direction, that is, the height direction, and in the X-axis direction and the Y-axis direction while vibrating the ultrasonic transducer. It is moved for cleaning.

Next, the dry wiping cleaning means will be described. The dry-wiping cleaning means is a dry-type cleaning means that simply wipes the back surface of the screen using a cleaning cloth or sponge. The unit of such cleaning means is movable in the Z-axis direction or the height direction and is pressed against the screen with a predetermined force. Further, the cleaning is performed along the lower surface of the screen by moving in the X-axis direction and the Y-axis direction. Such a dry-wiping cleaning means is useful as the above-mentioned suction cleaning using roll paper and the final finishing cleaning after ultrasonic cleaning with the ultrasonic vibrator.

Each of the above cleaning methods can be used alone. Further, by using two or three of these three methods in combination, it is possible to expect the same effect as the finish cleaning which has conventionally depended on the operator. In this case, wet ultrasonic cleaning is performed, and then suction cleaning with roll paper is performed. Finally, dry and dry cleaning should be performed. With this method,
Fully automated cleaning of the underside of the screen is achieved.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 and 2 show a front view and a side view of this screen printing apparatus, and FIG. 3 shows a front view showing the positioning unit of such an apparatus in principle. The outline of the screen printing apparatus will be described with reference to these drawings.

This screen printing apparatus has a support base 10 which stands upright on the back side. Further, on the lower surface of the support base 10, guide rails 11 and 12 extending in the lateral direction and vertically spaced apart from each other by a predetermined distance are provided, and the carriage 13 can be freely moved by these guide rails 11 and 12. Support. The carriage 13 supports a camera unit 14, and the image recognition camera 15 is supported by the camera unit 14. The image recognition camera 15 is for performing image recognition of a board, which will be described later.

Another carriage 65 is supported by the pair of guide rails 11 and 12. The cleaning unit 19 is supported by the carriage 65. The cleaning unit 19 is for cleaning the lower surface of the screen with a cleaning cloth or the like described later. The cleaning unit 19 includes suction cleaning means and ultrasonic cleaning means. Still another dry wiping cleaning means is attached to the camera unit 14. These cleaning means will be described in detail later.

A screen 25 is arranged above the moving range of the camera unit 14 and the cleaning unit 19. The screen 25 is stretched by a frame 26 with its four sides fixed. Then, the frame body 26 is fixed to a predetermined position of the printing apparatus by the mounting frame 27.

On the screen 25, a pair of squeegees 3
1, 32 are provided. The squeegees 31, 32 are supported by the supports 33, 34, respectively, and
34 are supported by air cylinders 35 and 36, respectively.

A pair of laterally extending guide rails 37 are provided on the surface of the support base 10 and above the support base 10.
38 are arranged, and these guide rails 37, 38
The carriage 39 is movably supported by.
The squeegees 31, 32 are laterally moved by the carriage 39.

Next, a positioning device for positioning the circuit board constituting the work below the screen 25 will be described. 3 and 4 show a specific configuration of this positioning device. As shown in FIGS. 3 and 4, this apparatus includes a base 43, and four Z-axis guides 44 are provided upright on the base 43. Then, the lower Z-axis table 45 is moved to Z by the Z-axis guide 44.
It is movably supported in the axial direction, that is, in the vertical direction. The Z-axis table 45 is pushed up by a rod 47 of an air cylinder 46 attached to the lower side of the base 43, and is vertically movable by a Z-axis guide 44. And Z-axis guide 4
The upper movement position is regulated by the stopper 48 provided on the No. 4.

A Y-axis table 51 is provided on the Z-axis table 45.
And the X-axis table 52 is mounted on the Y-axis table 51. A θ-axis table 53 is mounted on the X-axis table 52. A mounting plate 54 is mounted on the θ-axis table 53.

Four Z-axis guides 55 are arranged on the mounting plate 54 so as to extend upward, and the second Z-axis table 56 is supported by these guides 55 so as to be vertically movable. A motor (not shown) and a ball screw 57 of the Z-axis table 56 are interlocked with each other so that the Z-axis table 56 can be moved up and down.

On the second Z-axis table 56, further Z
A shaft guide 59 is provided, and the Z-axis guide 59 supports the third Z-axis table 60 so as to be able to move up and down. The height of the Z-axis table 60 is adjusted by the ball screw 61. Third Z-axis table 6
0 constitutes the uppermost table of the positioning unit 50, and a plurality of pins 62 are planted upright on the table so that the circuit board 98 is supported via the pins 62. It has become.

Next, a mechanism for cleaning the lower surface of the screen 25 of this screen printing apparatus will be described with reference to FIGS. X camera unit 14
A carriage 65 is provided by a pair of upper and lower guide rails 11 and 12 that are moved in the axial direction, as shown in FIG. The carriage 65 has suction cleaning means 66.
Is provided. The suction cleaning means 66 includes a supply roll 67, a winding roll 68, and a suction roll 69. In particular, as shown in FIG. 5, the suction roll 69 is provided with a slit 70 that extends in the axial direction on the upper surface of the suction roll 69 so as to be in contact with the screen 25, and the slit 70 performs the suction operation.

The cleaning cloth 71 is the supply roll 67.
The suction roll 69 cleans the lower surface of the screen 25 via the cleaning cloth 71 at this time. Such suction cleaning means 66 is shown in FIG.
As shown in B, the Z-axis rails 72 are provided on both sides in the length direction.
And is movable in the height direction by the Z-axis rail 72.

An ultrasonic cleaning means 75 is further provided on the carriage 65. The ultrasonic cleaning means 75 is provided with a pedestal 76 made of a rectangular plate-shaped body, on which the ultrasonic vibrator 7 is provided via a spring 77 as shown in FIG.
It supports a cleaning head with 8. The ultrasonic transducer 78 is arranged at the center of the ring-shaped member 79. The ring-shaped member 79 is made of cloth or sponge impregnated with the cleaning liquid. Further, the cleaning head composed of the ultrasonic transducer 78 and the ring-shaped member 79 is detachably covered with the lid 83.

As shown in FIG. 4A, the mount 76 is vertically movable by a Z-axis rail 80, and a Z-axis table 81 having the Z-axis rail 80 is moved by the Y-axis rail 82 in the Y-axis direction, that is, It can move laterally at right angles to the direction of movement of the squeegee.

A dry-wiping cleaning means 85 is provided on the carriage 13 including the camera unit 14. The dry-wiping cleaning means 85 has a support frame 86, and a cleaning member 87 is attached to the support frame 86. Here, the support frame 86 is movable in the height direction by the Z-axis rail 88. The Z-axis table 89 including the Z-axis rail 88 can be moved by the Y-axis rail 90 in the Y-axis direction, that is, in the direction perpendicular to the moving direction of the squeegee and in the width direction of the screen.

FIG. 8 shows a control system for the drive section of such three types of cleaning means. This control system includes a controller 100 and the controller 10.
An input device 99 is connected to the input side of 0. On the other hand, on the output side of the controller 100, suction, ultrasonic X-axis drive 101, suction cleaner Z-axis drive 1
02, ultrasonic cleaner Z-axis drive 103, ultrasonic cleaner Y-axis drive 104, ultrasonic cleaner drive unit 10
5, camera unit X-axis drive 108, camera unit Y-axis drive 109, dry-cleaning cleaner Z-axis drive 1
10 are connected to each other.

Next, the operation of the screen printing apparatus having such a configuration will be described. First, the overall operation of this printing apparatus will be described. When the circuit board 98 does not exist on the conveyor belt 93 shown in FIG. 3, the Y-axis table 51 and the X-axis table 52 of the positioning unit 50 operate, The upper part of the positioning unit 50 moves to the carry-in conveyor 94 side. Then, the carry-in conveyor 94 and the conveyor belt 93 are operated to introduce the circuit board 98 onto the conveyor belt 93, and the circuit board 98 is stopped at a predetermined position and also the conveyor belt 93 is stopped. FIG. 3 shows the circuit board 98 stopped at this position.

Next, the second Z-axis table 56 is raised by a motor and a ball screw 57 (not shown), and the circuit board 98.
Is lifted from the conveyor belt 93. After that, the circuit board 98 is fixed and the warp is corrected. After correcting the warp of the circuit board 98 and fixing the circuit board 98 on the third Z-axis table 60 of the positioning unit 50, the camera unit 14 is guided by the carriage 13 to the guide rail 1.
The image recognition camera 15 is moved along the substrate 1 and 12 and moves above the substrate 61 to recognize the alignment mark on the substrate 61.

The X-axis table 52 and the Y-axis table 5 are controlled by the control unit in conjunction with the detection of the alignment marks on the circuit board 98 by the image recognition camera 15.
1. The θ-axis table 53 is driven to correct the positional deviation of the circuit board 98. Then, after this, the air cylinder 46 is operated to raise the entire positioning unit 50 and move it upward to a position where the circuit board 98 is brought into contact with the lower surface of the screen 25.

Then, in such a state, the squeegees 31, 3 are
2 slides on the screen 25 to print cream solder. After completing a series of printing operations, the ball screw 6
1 moves the third Z-axis table 60 downwards, thereby separating the circuit board 98 from the screen 25. After this, the lower Z-axis table 45 is lowered by the air cylinder 46. Then, after this, the X-axis table 52 and the Y-axis table 51 are driven, the positioning unit 50 is moved to the discharge conveyor 95 side, the conveyor belt 93 and the discharge conveyor 95 are operated together, and the circuit board 98 is discharged to the discharge conveyor 95. To discharge by.

In the screen printing apparatus for printing the cream solder on the surface of the circuit board 98 in this manner, the carriages 65 and 13 are provided below the screen 25 as shown in FIGS. 4A and 4B as described above. And these are guided by common guide rails 11 and 12. A suction cleaning unit 66 and an ultrasonic cleaning unit 75 are mounted on the carriage 65, and a dry-wiping cleaning unit 85 is mounted on the carriage 13 together with the camera unit 14.

The suction cleaning means is equipped with a suction roll 69. The suction roll 69 has a slit 70 formed in the pipe and both ends thereof are closed to provide a vacuum suction hole (not shown), which is connected to a vacuum source. Then, it is mounted on the carriage 65 along with the supply roll 67 and the take-up roll 68 by a Z-axis rail 72 so that it can be raised and lowered. On the other hand, the ultrasonic cleaning means is supported by the carriage 65 by the Z-axis rail 80 and the Y-axis rail 82 so as to be movable in the height direction and the Y-axis direction. Carriage 6
When 5 moves to the right in FIG. 4, ultrasonic cleaning precedes, and then suction cleaning is performed.

In particular, the ultrasonic cleaning means is provided with a cleaning head composed of an ultrasonic vibrator 78 and a ring-shaped member 79 around it, as shown in FIG. The ring-shaped member is made of cloth, non-woven fabric, sponge or the like, and is impregnated with a solvent. The ring-shaped member is biased upward by the spring 77 so that the lower surface of the screen 25 can be equalized.

Carriage 1 together with camera unit 14
In the dry-wiping cleaning means 85 supported by 3, the cleaning head is constituted by the cleaning member 87 attached to the support frame 86. It is preferable that the portion of the cleaning head that comes into contact with the screen 25 is made of a material such as a non-woven fabric that hardly generates foreign matter.
The cleaning head can be moved in the height direction by the Z-axis rail 88, and can be moved in the Y-axis direction along the Y-axis rail 90.

FIG. 9 shows the flow of the cleaning operation by the three kinds of cleaning means, that is, the suction cleaning means 66, the ultrasonic cleaning means 75, and the dry-wiping cleaning means 85. That is, here, the basic operation in the case of automatically performing suction cleaning or ultrasonic cleaning to dry cleaning is shown. The screen printing apparatus according to the present embodiment includes the above-mentioned three types of cleaning means and is configured to be used independently, so that the basic operation of the flow of FIG. It is possible to add additional cleaning or to use alone.
To change the cleaning order or the combination, the input device 99 connected to the controller 100 is used.
Achieved by giving instructions by.

A case where the cleaning operation is performed in the order of suction cleaning, ultrasonic cleaning and dry wiping cleaning will be described with reference to the flowchart of FIG. The suction cleaner Z-axis drive 102 is driven, thereby raising the suction cleaning means 66 along the Z-axis rail 72. Then, after this, the suction roll 69 is vacuum-sucked, and the cleaning cloth 71 is cleaned by the slit 70. At this time, the cleaning area on the lower surface of the screen 25 is adjusted by suction and a moving stroke of the carriage 65 by the ultrasonic X-axis drive 101.

When performing ultrasonic cleaning after this, the ultrasonic cleaner Z-axis drive 103 is operated to bring the cleaning head into contact with the lower surface of the screen 25. Then, ultrasonic cleaning is performed with the cleaning liquid supplied from the ring-shaped member 79 while vibrating the ultrasonic vibrator 78 by the ultrasonic cleaner driving unit 105. At this time, the cleaning area on the lower surface of the screen 25 is adjusted by the movement amount of the carriage 65 in the X-axis direction and the movement amount of the ultrasonic cleaning means 75 along the Y-axis rail 82. When the ultrasonic cleaning of the predetermined area is completed, the ultrasonic cleaner Z-axis drive 1
03, the ultrasonic cleaning means 75 is lowered and the carriage 65 is moved to the retracted position, that is, the left side position shown in FIG.

After that, the carriage 13 is moved along the guide rails 11 and 12, and the dry-wiping cleaning means 85 is moved to the lower side of the screen 25. Then, the dry wiping cleaner Z-axis drive 110 raises the cleaning head of the dry-wiping cleaning means 85 along the Z-axis rail 88 to bring it into contact with the lower surface of the screen 25. Then, the carriage 13 is moved in the X-axis direction and the dry-wiping cleaning means 85 is moved along the Y-axis rail 90 to clean a predetermined area on the lower surface of the screen 25. When the cleaning is finished, the dry-wiping cleaner Z-axis drive 110 lowers the dry-wiping cleaning means 85. After this, the carriage 13 is retracted to the retracted position shown in FIG. This completes the cleaning operation.

According to such a screen printing apparatus,
Three functions, suction cleaning, ultrasonic cleaning, and dry wiping cleaning are provided, which provides a high cleaning effect on the screen 25, and the operation of wiping the lower surface of the screen 25 by a conventional operator is fully automated to improve skills. It becomes possible to achieve less. Further, the three types of cleaning methods can be used separately, and the three types of cleaning methods described above can be flexibly dealt with by arbitrarily selecting or combining the three cleaning methods depending on conditions such as the degree of dirt on the screen.

The suction cleaning means is a slit 70.
Since the suction cleaning is performed by the suction roll 69 including, the high suction efficiency can be obtained.
Further, since the ultrasonic cleaning means arranges the ring-shaped member 79 impregnated with the cleaning liquid around the ultrasonic vibrator 78, a high ultrasonic cleaning effect is exhibited. Further, by using dry wiping cleaning together, the optimum cleaning condition can be selected for the dirt of the screen 25.

The invention of the present application has been described above with reference to the embodiment shown in the drawings. However, the invention of the present application is not limited to the above-described embodiment, and various modifications can be made within the scope of the technical idea of the invention included in the present application. Is. For example, the above embodiment relates to the printing apparatus for cream solder, but the invention of the present application can be widely applied to printing apparatuses for various other paste substances.

[0060]

The main invention of the present application is screen printing in which a work is superposed on a lower surface of a screen at a predetermined position and a paste-like substance is printed on the surface of the work through an opening of the screen. In the device,
Suction cleaning means for sucking and cleaning the lower surface of the screen using a cleaning cloth, ultrasonic cleaning means for wet-cleaning the lower surface of the screen by vibration of an ultrasonic transducer, and dry-wiping cleaning means for wiping the lower surface of the screen. And so on.

Therefore, according to such a screen printing apparatus, one or more cleaning means among the suction cleaning means, the ultrasonic cleaning means, and the dry-wiping cleaning means are selected or combined. , It becomes possible to clean the lower surface of the screen more completely. Therefore, it is possible to prevent the paste-like substance from accumulating on the lower surface through the opening of the screen and deteriorating the printing accuracy, and it becomes possible to perform high-precision screen printing.

The main invention relating to the cleaning method is
In a screen printing device in which a work is superposed on a predetermined position on the lower surface of the screen and a paste-like substance is printed on the surface of the work through an opening portion of the screen, the lower surface of the screen is cleaned through a cleaning cloth. A suction cleaning means for sucking and cleaning, an ultrasonic cleaning means for wet-cleaning the lower surface of the screen by vibration of the ultrasonic transducer, and a dry-wiping cleaning means for wiping the lower surface of the screen are provided, and three types of cleaning means are provided. Any one kind or two or more kinds of cleaning means is selected to clean the paste-like substance attached to the lower surface and the opening of the screen.

Therefore, according to such a cleaning method of the screen printing apparatus, it becomes possible to clean the lower surface of the screen by selecting one or more kinds out of the three kinds of cleaning means, and the lower surface of the screen. It is possible for the operator to omit the work of wiping by hand, and to achieve complete skilllessness.

[Brief description of drawings]

FIG. 1 is a front view of essential parts showing the overall configuration of a screen printing apparatus.

FIG. 2 is a side view of the main part.

FIG. 3 is a front view of a main part showing the configuration of a positioning unit.

FIG. 4 is a front view and a plan view showing a cleaning mechanism.

FIG. 5 is a plan view of a suction roll of a suction cleaning unit.

FIG. 6 is a longitudinal sectional view of a main part of an ultrasonic cleaning head.

FIG. 7 is a plan view of a main part of a dry-wiping cleaning unit.

FIG. 8 is a block diagram showing a control system.

FIG. 9 is a flowchart showing an example of a cleaning operation.

[Explanation of symbols]

10 ... Support base, 11, 12 ... Guide rail, 13
Carriage, 14 Camera unit, 15 Image recognition camera, 19 Cleaning unit, 25
... screen, 26 ... frame, 27 ... mounting frame, 31, 32 ... squeegee, 33, 34 ... support,
35, 36 ... air cylinder, 37, 38 ... guide rail, 39 ... carriage, 43 ... base, 44 ... Z
Axis guide, 45, Z axis table, 46, air cylinder, 47, rod, 48, stopper, 50, positioning unit, 51, Y axis table, 52, X axis table, 53, θ Axis table, 54 ... Mounting plate, 5
5 ... Z-axis guide, 56 ... 2nd Z-axis table, 57 ...
Ball screw, 59 Z-axis guide, 60 Third Z-axis table, 61 ball screw, 62 pin, 65
Carriage, 66, suction cleaning means, 67
Supply roll, 68, take-up roll, 69, suction roll, 70, slit, 71, cleaning cloth, 72, Z-axis rail, 75, ultrasonic cleaning means, 76, pedestal, 77. ... Spring, 78 ... Ultrasonic transducer, 79 ... Ring-shaped member, 80 ... Z-axis rail, 8
1 ... Z-axis table, 82 ... Y-axis rail, 83 ... lid, 85 ... dry-wiping cleaning means, 86 ... support frame, 87 ... cleaning member, 88 ... Z-axis rail,
89 ... Z-axis table, 90 ... Y-axis rail, 93 ...
Conveyor belt, 94, carry in conveyor, 95, discharge conveyor, 98, circuit board (work), 99, input device, 100, controller, 101, suction, ultrasonic X-axis drive, 102, suction Cleaner Z-axis drive, 103 ... Ultrasonic cleaner Z-axis drive, 104 ...
・ ・ ・ Ultrasonic cleaner Y-axis drive, 105 ・ ・ ・ Ultrasonic cleaner driver, 108 ・ ・ ・ Camera unit X-axis drive,
109: Camera unit Y-axis drive, 110: Dry-wiping cleaner Z-axis drive

Continued front page    F-term (reference) 2C035 AA06 FD29                 2C250 FA06 FB12 FB16 FB17                 5E319 BB05 CD29 GG15

Claims (13)

[Claims] 1. A screen printing apparatus in which a work is placed on a lower surface of the screen at a predetermined position and a paste-like substance is printed on the surface of the work through an opening of the screen. Suction cleaning means for sucking and cleaning the lower surface of the screen by using the ultrasonic cleaning means, ultrasonic cleaning means for cleaning the lower surface of the screen in a wet manner by vibration of an ultrasonic transducer, and dry-wiping cleaning for wiping the lower surface of the screen. A screen printing apparatus comprising: 2. The suction cleaning means comprises a supply roll, a take-up roll and a suction roll, roll paper constituting a cleaning cloth is supplied from the supply roll, and the roll paper is wound around the suction roll. The screen printing apparatus according to claim 1, wherein the lower surface of the screen is cleaned by sucking the rolled paper, and the cleaned roll paper is wound by a winding roller. 3. The suction roll is made of a hollow pipe, and a slit is formed on a generatrix so as to be in contact with the lower surface of the screen, and the inside is vacuum sucked to suck the lower surface of the screen through the roll paper. The screen printing apparatus according to claim 2, wherein the screen printing apparatus is cleaned. 4. The suction cleaning means is arranged so as to extend in a direction orthogonal to a sliding direction of a squeegee sliding on the screen, and is movable in a moving direction and a height direction of the squeegee. Claim 1 characterized by the above-mentioned.
The screen printing apparatus described in 1. 5. The ultrasonic cleaning means has a ring-shaped member impregnated with a cleaning liquid, the ultrasonic vibrator is arranged at the center of the ring-shaped member, and the ring-shaped member is arranged in the height direction. 2. A movable unit that can be moved close to and away from the screen.
The screen printing apparatus described in 1. 6. The ultrasonic cleaning means comprises a supply means for supplying a cleaning liquid to the cleaning head when the cleaning head composed of the ultrasonic vibrator and the ring-shaped member is in a standby position. The screen printing apparatus according to claim 5, wherein the cleaning head further includes a lid that prevents evaporation of the cleaning liquid. 7. The ultrasonic cleaning means is configured to be movable in a sliding direction of a squeegee sliding on a screen, a lateral direction perpendicular to the sliding direction of the squeegee, and a height direction. The screen printing device according to claim 1. 8. The screen printing apparatus according to claim 1, wherein the dry-wiping cleaning means is composed of a dry-wiping cleaning cloth or sponge and is supported by a supporting member. 9. The dry-wiping cleaning means is configured to be movable in a sliding direction of a squeegee sliding on a screen, a lateral direction perpendicular to the moving direction of the squeegee, and a height direction. 1. The screen printing device according to 1. 10. The screen printing apparatus according to claim 1, wherein the work is a circuit board and the paste-like substance is cream solder. 11. A screen printing apparatus, wherein a work is superposed on a lower surface of the screen at a predetermined position and a paste-like substance is printed on the surface of the work through an opening of the screen. Suction cleaning means for sucking and cleaning the lower surface of the screen via the ultrasonic cleaning means, ultrasonic cleaning means for performing wet cleaning of the lower surface of the screen by vibration of an ultrasonic transducer, and dry wiping cleaning for wiping the lower surface of the screen. Means for cleaning the paste-like substance adhering to the lower surface and the opening of the screen by selecting one or more of the three kinds of cleaning means. How to clean a printing device. 12. A method of cleaning a screen printing apparatus, comprising: cleaning the lower surface of a screen in the order of ultrasonic cleaning, suction cleaning, dry wiping cleaning, or suction cleaning, ultrasonic cleaning, dry wiping cleaning in this order. 13. The method for cleaning a screen printing device according to claim 11, wherein the work is a circuit board, and the paste-like substance is cream solder.