JP2005288951A - Screen printing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printing machine, the upsizing of a device of which is prevented from developing and with which highly fine and high grade printing is possible by providing a cleaning mechanism for removing foreign matters adhered on a board at the inlet of the printing machine. <P>SOLUTION: This screen printing machine is so constituted as to equip with a printing table equipped with positioning mechanisms and lifting mechanisms of X-axis, Y-axis and θ-axis, a mask, which is stretched on an screen frame and has a transfer pattern as an opening part, a camera picturizing positioning marks provided on the board and on the mask, a squeegee, a squeegee head equipped with a lifting mechanism and a horizontally moving mechanism of the squeegee, a board taking-in conveyor, a board taking-out conveyor, a controller for controlling these mechanisms and an ionizer and a vacuum suction nozzle for removing foreign matters adhered onto the top surface of the board at or after its taking-in. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a screen printer used for supplying an electronic material paste such as cream solder to an electronic circuit board, and more particularly to a screen printer capable of performing high-quality printing.

  As shown in Patent Document 1, in a conventional screen printing machine in which ink is applied to a substrate surface using a squeegee or the like through a mask having openings that are opened according to a pattern to be printed, residual ink is applied to the mask surface. However, since there is a possibility of adversely affecting the application to the next substrate, many configurations for cleaning the mask surface have been proposed.

  Patent Document 2 proposes a cleaning device that cleans the liquid crystal glass substrate surface using a solvent.

Japanese Patent Laid-Open No. 5-229108

JP 2003-53281 A

  By the way, when performing solder bump printing, printing of a sealant for a liquid crystal substrate, or the like in a screen printing machine, the print pattern tends to be highly precise. As the pattern becomes higher in definition, foreign matter may adhere to the substrate surface due to electrostatic force or the like, and printing may be adversely affected. In order to clean the substrate surface, a device as shown in Patent Document 2 may be provided separately from the screen printing machine. However, this increases the size of the device and also requires a device for delivering the substrate.

  Accordingly, an object of the present invention is to provide a printing machine capable of preventing the enlargement of the apparatus and capable of high-definition and high-quality printing by providing a cleaning mechanism for removing foreign matter adhering to the substrate at the entrance of the printing machine. There is to do.

  In order to achieve the above object, in the present invention, a printing table provided with an X-axis, Y-axis, and θ-axis positioning mechanism and an elevating mechanism, a mask pasted on a plate frame and having a transfer pattern as an opening, a substrate and a mask It is equipped with a camera that images the provided positioning marks, a squeegee, a squeegee head equipped with a squeegee lifting mechanism and a horizontal movement mechanism, a substrate carry-in conveyor, a substrate carry-out conveyor, and a control device that controls these mechanisms. In this configuration, an ionizer and a vacuum suction nozzle for removing foreign matter adhering to the upper surface are provided.

  With the above-described configuration, the foreign matter attached on the substrate can be removed before printing, and is not affected by the foreign matter at the time of printing. Therefore, high-definition and high-quality printing can be performed.

  Next, the cleaning device for the carry-in substrate will be described with reference to FIGS.

  In FIG. 1, a squeegee head 3 is provided at the upper part of a main body frame 1 of the screen printing machine, guided by a pair of guide rails 2 and movable in the front-rear direction in the figure. The squeegee head 3 is moved horizontally (front-rear direction) on the screen mask 8 by a drive mechanism including a ball screw 4 and a motor (not shown) for rotating the ball screw 4.

  A squeegee 5 is mounted on the squeegee head 3. The squeegee 5 can be moved up and down by a squeegee lifting cylinder 6. A plate frame receiver 7 is provided on the main body frame 1, and a plate frame 9 with a screen (mask) 8 having a printing pattern as an opening is set on the plate frame receiver 7. A printing table 10 is provided below the screen mask. The printing table 10 includes an XYθ table 11 and a table lifting mechanism (not particularly shown). A substrate receiving conveyor 12 is provided on the upper surface of the printing table 10. The substrate receiving conveyor 12 receives the substrate 15 carried in by the substrate carry-in conveyor 13 on the printing table 10, and discharges the substrate 15 to the substrate carry-out conveyor 14 when printing is completed.

  The fully automatic screen printer has a function of automatically aligning the mask 8 and the substrate 15. In order to perform alignment, the CCD camera 16 images the alignment marks provided on the mask 8 and the substrate 15, respectively, and recognizes their positions. An ionizer 30 for spraying ions onto the substrate surface is provided above the carry-in conveyor 13 serving as a substrate carry-in section in order to neutralize charges charged on the upper surface of the substrate 15 carried into the screen printer. Further, a vacuum suction nozzle 31 for sucking and removing foreign matter adhering to the substrate 15 is provided downstream of the ionizer 30 in the substrate transport direction. The ionizer 30 and the vacuum suction nozzle 31 are attached below a bracket 32 provided on the main body 1.

  On the upstream side of the substrate carry-in conveyor 13 of the printing machine, a loader (substrate supply device) 40 is provided that stores a plurality of substrates and supplies the substrates to the substrate carry-in conveyor of the printing machine one by one. Is provided with a carry-out conveyor 41 for delivering the substrate to the board carry-in conveyor 13.

  FIG. 2 is an AA arrow view of FIG. In particular, the state where the substrate is mounted on the substrate carry-in conveyor 13 and the substrate 15 is being cleaned is shown. As shown in FIG. 2, the flow direction of the substrate 15 is such that the ionizer 30 and the vacuum suction nozzle 31 are positioned upstream of the vacuum suction nozzle 31 with respect to the flow direction of the substrate 15 (arrow direction in the figure). It is arranged at a right angle. That is, when the substrate 15 passes under the ionizer 30 provided on the substrate carry-in conveyor 13, ions that neutralize the charge that charges the substrate 15 are sprayed from the ionizer 30, and the foreign matter attached to the substrate 15. The electrostatic attraction force is weakened. Next, when the substrate 15 reaches under the vacuum suction nozzle 31 portion, the foreign matter is collected in the nozzle by a vacuum suction force. This foreign material recovery mechanism will be described later.

  FIG. 3 is a BB step view of FIG. In FIG. 3, the ionizer 30 is provided with an air supply pipe 34 connected to a delivery port of a blower (not shown) for supplying clean air. The vacuum suction nozzle 31 is provided with a vacuum suction pipe 33 connected to a suction port of a vacuum pump (not shown).

  4 is a cross-sectional view taken along the line CC of FIG. 3 (a cross-sectional view in the longitudinal direction of the vacuum suction nozzle). As shown in FIG. 4, the opening 36 of the vacuum suction nozzle 31 needs to have a length sufficient to cover the maximum width of the substrate 15 that can be printed by the screen printing machine of the present invention. However, when printing on the substrate 15 having a width narrower than the maximum printable substrate width as shown in FIG. A portion where the opening 36 is detached from the substrate 15 is generated. In that case, the air resistance of the opening part removed from the substrate 15 is significantly smaller than the air resistance of the opening part on the upper part of the substrate 15. For this reason, most of the suction air volume of the vacuum suction nozzle 31 flows through the opening portion deviating from the substrate width, and the vacuum suction force on the upper surface of the substrate 15 is significantly reduced. Therefore, in the present invention, the shutter 35 is provided in order to prevent the above problems. The position of the shutter 35 can be adjusted so that the length of the opening 36 of the vacuum suction nozzle 31 substantially matches the width of the substrate 15 supplied to the printing press. FIG. 5 is a cross-sectional view taken along the line D-D of FIG.

  FIG. 6 is a circuit diagram showing an example of the air circuit of the substrate upper surface cleaning unit in the screen printing machine according to the present invention. The screen printing machine of the present invention includes a mask cleaning device 24 including a suction nozzle 24A. The blower 45, which is an air pressure source, is provided with an air switching valve 53 in order to share the air source of the substrate upper surface cleaning section and the air source for mask cleaning. When the air switching valve 53 is in the neutral position C, the suction port 46 and delivery port 47 of the blower 45 communicate with each other through the bypass port of the air switching valve 53, and the blower 45 is connected to both the substrate upper surface cleaning portion and the mask cleaning portion. Absent. When the air switching valve 53 is switched to the substrate upper surface cleaning position A, the suction port 46 of the blower 45 is connected to the suction pipe 33 of the vacuum suction nozzle 31 and the delivery port 47 is connected to the air supply pipe 34 of the ionizer 30. On the other hand, when the air switching valve 53 is switched to the mask cleaning position B, the suction port 46 of the blower 45 is connected to the suction pipe 51 of the mask cleaning suction nozzle 24, and the delivery port 47 is connected to the exhaust port of the air switching valve 53.

  In FIG. 6, a filter 52 for trapping paste is provided on the blower side of the suction nozzle 24 for cleaning the mask, and a filter 38 for trapping foreign matter is provided on the blower side of the vacuum suction nozzle 31 for cleaning the substrate surface. Is provided. By constructing an air circuit as shown in FIG. 6, it is possible to generate air blow for ions, vacuum force for vacuum suction, and vacuum force for suction for mask cleaning with a single blower.

  In addition, in the Example, the board | substrate upper surface cleaning part of the screen printing machine demonstrated as a structure arrange | positioned on the board | substrate carrying-in conveyor 13. FIG. As another configuration, although not shown, a mask cleaning unit including a mask cleaning suction nozzle 24 and the like is provided so as to be movable between the mask 8 and the table 10. An ionizer 30 and a vacuum suction nozzle 31 can also be installed below the mask cleaning unit that sucks and removes the paste remaining on the mask from the suction nozzle 24 due to negative pressure. By providing the ionizer 30 and the vacuum suction nozzle 31 in the mask cleaning unit, it is possible to clean the upper surface of the substrate while moving the mask cleaning unit on the substrate 15 after the substrate 15 is carried onto the printing table 10. Further, it is not contrary to the gist of the present invention to arrange a substrate top surface cleaning device, which is a combination of an ionizer and a vacuum suction nozzle, as a separate device upstream of the screen printing machine. Moreover, a mask cleaning part can be stopped so that it may be located in the upper part of the board | substrate carrying-in conveyor 13, and a board | substrate can also be cleaned. Thus, by providing the substrate cleaning unit in the mask cleaning unit, it is not necessary to provide the bracket 32 in the printing press main body 1, and the size of the apparatus can be reduced.

It is a figure of one Example of the cream solder printer provided with the board | substrate cleaning mechanism. It is AA sectional drawing of FIG. 1, and is a top view for demonstrating a substrate cleaning state. It is BB sectional drawing of FIG. FIG. 4 is a CC step view of FIG. 3. FIG. 5 is a DD step view of FIG. 4. It is the figure which showed an example of the air pressure control system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Main body, 3 ... Squeegee head, 5 ... Squeegee, 6 ... Cylinder, 8 ... Mask, 9 ... Plate frame, 10 ... Print table, 12 ... Substrate delivery conveyor 13 ... Substrate carry-in conveyor, 14 ... Substrate carry-out conveyor, 15 ... Substrate, 17 ... CCD camera, 24 ... Mask cleaning suction nozzle, 30 ... Ionizer, 31 ... Vacuum suction nozzle, 35 ... Shutter, 36 ... Opening.

Claims (3)

X-axis, Y-axis and θ-axis positioning mechanism and printing table provided with a lifting mechanism, a mask pasted on a plate frame and having a transfer pattern as an opening, a camera for imaging a positioning mark provided on the substrate and the mask, a squeegee, In a squeegee head equipped with a squeegee lifting mechanism and a horizontal movement mechanism, a board carry-in conveyor, a board carry-out conveyor, and a screen printing machine equipped with a control device for controlling these mechanisms,
A screen printing machine comprising an ionizer and a vacuum suction nozzle for removing foreign matter adhering to the upper surface of a substrate when the substrate is loaded or after the substrate is loaded. The screen printer according to claim 1, wherein
A screen printing machine, wherein the vacuum suction nozzle is provided with a shutter for adjusting an opening of the vacuum suction nozzle according to a substrate width. The screen printer according to claim 1, wherein
In order to clean the mask, a mask cleaning part with a suction port is provided,
The blower used for air blowing from the ionizer and air suction by the vacuum suction nozzle is shared with the air suction blower of the mask cleaning unit, and a switching valve for switching the functions of both is provided. Screen printing machine.

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