JP2006224475A - Screen printing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that it becomes hard for a conventional squeegee to cope with the minuteness of a printing area of a printing object and that equipment becomes large in size, as the printing area becomes more minute. <P>SOLUTION: A printing table equipped with a mechanism for movement on an X-axis, a Y-axis and a θ-axis and a lifting mechanism, a mask which is stuck to a plate frame and has a transfer pattern as an opening part, a camera which picks up images of positioning marks provided on a substrate and the mask, and a squeegee head which is equipped with a squeegee disposed above the mask and brought into contact with the top of the mask so as to supply paste onto the surface of the substrate and with a squeegee lifting mechanism for moving the squeegee vertically and a horizontally moving mechanism, are provided. The squeegee has a structure that two steel blades are disposed with a resin spacer held between and the thickness of the blade on the rear side in the direction of movement of the squeegee on the occasion of printing is made larger than that of the blade on the front side in this direction, while the length of the blade on the rear side is set to be larger than that of the blade on the front side. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a screen printing apparatus, and more particularly to a metal blade provided in a print head and a screen printing apparatus using the metal blade.

  In a conventional screen printing apparatus, as disclosed in Patent Document 1, a plurality of blades are overlapped to form a straw squeegee blade, and can be moved up and down between the blades, in order to print an advanced / fine pitch pattern. There is disclosed a squeegee having a configuration in which a narrow blade is provided, residue in the narrow portion is discharged by the narrow blade to prevent the blade from solidifying, and the front edge of the printing surface is flat and sharp.

  Patent Document 2 discloses a screen printing machine having a configuration in which two squeegees that act in the same direction at predetermined intervals are provided. Thus, by providing two squeegees, the screen mask between the first and second squeegees and the substrate to be printed are brought into close contact with each other for a predetermined time, and the screen mask having fine lines with a line width of less than 50 μm is used. Is described as being able to achieve line printing without bubble defects or disconnection.

JP-A-9-99539 JP 2003-145709 A

  In the technique described in the above-mentioned Patent Document 1, it is said that a squeegee blade suitable for printing using a clean fine pitch pattern of wide, narrow, large and small is provided. However, it is only disclosed that the tip is made flat and sharp, and it is unclear how the structure can be applied to a fine pitch mask. Further, if the squeegee blades are simply overlapped, the pressing pressure (pressing force) for pressing the blades against the mask increases, and the mask is easily damaged.

  Further, in the method of Patent Document 2, the screen mask cannot be adhered to the printed material for a predetermined time unless the distance between the two squeegees is separated by a predetermined distance. Since it is necessary to provide a mechanism for variable control, problems such as an increase in the size of the apparatus occur.

  The object of the present invention is a small squeegee structure that can print without applying a large pressure to the squeegee, and can prevent printing material from remaining as a residue on the surface of the printed material, corresponding to a fine pitch mask. And providing a screen printing machine using the same.

  In order to achieve the above object, in the present invention, a printing table having an X-axis, Y-axis, and θ-axis moving mechanism and an elevating mechanism, a mask pasted on a plate frame and having a transfer pattern as an opening, a substrate, A camera that images a positioning mark provided on the mask; a squeegee that is disposed on the upper side of the mask and that abuts on the mask to supply paste to the substrate surface; and a squeegee lifting mechanism that moves the squeegee up and down A squeegee head with a horizontal movement mechanism, and the squeegee has two steel blades sandwiched between resin spacers, with respect to the thickness of the blade on the front side in the movement direction of the squeegee, The thickness of the rear side blade is increased, and the length of the rear side blade is set longer than the length of the front side blade.

  By setting the blade rigidity low, the blade tip increases the followability with respect to each pattern, and even if the pressing force is reduced, the filling performance of each opening is maintained even in a narrow opening on an uneven substrate. . Furthermore, by providing a rear blade that is more rigid than the front blade, the adhesion of the printing material to the substrate is increased, and the residual printing material on the mask in the vicinity of the opening is removed to facilitate separation of the plate. . As a result, the yield of printing can be improved, and a large pressing force does not act on the mask, so that the life of the mask can be extended.

  The present invention will be described below with reference to the drawings.

  FIG. 1 shows a schematic view of a screen printing apparatus to which the metal blade of the present invention is applied.

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

  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. In this figure, one squeegee 5 is provided. However, in the case where two squeegees 5 and two lifting cylinders are provided and printing is performed while the squeegee head 3 is reciprocated, the squeegee 5 to be used may be changed between the forward path and the backward path for printing. 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 8 at a predetermined interval. 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. In the present embodiment, the substrates are loaded and unloaded by the substrate carry-in conveyor 13, the substrate receiving conveyor 12, and the substrate carry-out conveyor 14. However, it goes without saying that the substrates may be manually set on the printing table.

  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 the positions thereof. If there is a positional deviation, the XYθ table 11 is driven to perform alignment.

  Next, the operation of the screen printing machine of the present invention will be described with reference to FIG.

  The substrate 15 on which the electronic material paste is printed is supplied to the substrate receiving conveyor 12 by the substrate carry-in conveyor 13 and fixed at a predetermined position on the printing table 10. Subsequently, the CCD camera 16 takes an image of a position recognition mark (not shown) provided on the substrate 15 and the mask 8 and transfers it to a control device (not shown). In an image processing device (not shown) in the control device, the amount of positional deviation between the mask 8 and the substrate 15 is obtained from the image data, and based on the result, the control device operates the XYθ table 11 of the printing table 10 to operate the mask 8. The position of the substrate 15 relative to is corrected. Thereafter, the printing table 10 is raised, and the substrate 15 and the mask 8 are brought into contact with each other. Thereafter, the squeegee 5 is lowered onto the mask surface by the squeegee lifting cylinder 6, and the front blade 24 and the rear blade 25 provided on the squeegee 5 are pressed against the mask with a predetermined pressing force. Thereafter, the electronic material paste supplied on the mask 8 by the movement of the squeegee head 3 is filled in the opening of the mask 8 and transferred to the substrate. The squeegee 5 rises after a certain distance stroke in the horizontal direction. Then, the printing table 10 is lowered, the mask 8 and the substrate 15 are separated, and the electronic material paste filled in the opening of the mask 8 is transferred to the substrate 15.

  Then, the substrate 15 printed with the electronic material paste is sent to the next process via the substrate carry-out conveyor 14.

  In particular, the present invention relates to the configuration of the squeegee 5 provided in the squeegee head 3, and the configuration will be described below with reference to FIG.

  FIG. 2 shows a cross-sectional view of the blade portion of the squeegee. As shown in FIG. 2A, the squeegee of the present invention has a configuration in which blades 24 and 25 formed of two steel plates are provided at a predetermined interval. The blades 24 and 25 have a shape that is long in the direction perpendicular to the moving direction of the head 3. The front blade 24 (hereinafter referred to as a front blade) is configured to be shorter than the rear blade 25 (hereinafter referred to as a rear blade) with respect to the moving direction (arrow direction) of the head 3. Further, when the thickness of the front blade 24 is set to 50 to 80 μm, the thickness of the rear blade 25 is set to about 100 μm. Further, a resin spacer 23 having a thickness of 5 to 10 mm is provided between the front blade 24 and the rear blade 25. By making the spacer 23 made of resin, the squeegee 5 is reduced in weight. The blades 24 and 25 are set to an angle θ (θ = 50 degrees to 70 degrees) in the drawing so that the tip corners come into contact with the mask 8 surface (when in a horizontal state). At this set angle, pressure (pressing force) is not applied from the blade to the mask. Further, the length of the front blade 24 is set to the length of the rear blade 25 so that when the front blade 24 is brought into contact with the mask surface so as to have this angle, the tip corner portion of the rear blade 25 is also in contact with the mask 8 in the same manner. Shorter than that. Further, blade pressing metal plates 21 and 22 having the same length as the spacer 23 are provided on the outer side of each blade, and each blade is sandwiched and fixed between the spacer 23 and the blade pressing metal plates 21 and 22 ( It is screwed). Further, as shown in the enlarged view of FIG. 2B, the blade pressing metal plate 21 on the front blade 24 side is provided with a notch with an angle of ψ (ψ = 20 to 40 degrees). . The squeegee 5 is configured by attaching the blades 24 and 25 to the squeegee cover 20 with the blade pressing metal plates 21 and 22 fixed thereto. The squeegee elevating cylinder 6 and the squeegee cover 20 are connected, and the squeegee elevating cylinder 6 moves the squeegee 5 up and down so that the blades 24 and 25 can contact or separate from the mask 8 with a predetermined pressure. ing. The pressing force for pressing the blade in this configuration against the mask is about 9N to 50N.

  As described above, it is possible to perform desired pattern printing by moving the substrate 15 (driving the XYθ table) in a state where each blade simultaneously contacts the mask at a predetermined contact angle.

  The reason for setting the inclination of the squeegee (angle formed by the mask 8 and the blades 24 and 25: attack angle) to θ as described above is that if the inclination is set to be equal to or less than the set inclination, the attack angle during pressurization is the rigidity of the blade. Is smaller, so it is even smaller. Therefore, the printing material is accumulated between the blades 24 and 25 and the mask 8, the fluidity is reduced, a large force is required to push the printing material into the opening of the mask 8, and the blade 24 is increased when the angle is increased. , 25 and the area of the contact portion between the mask 8 is increased, and the printing material is clogged during this time, so that a large pressing force is required for printing. Further, the cutting portion of the blade pressing metal plate 21 is provided with a notch portion having an inclination angle ψ to prevent clogging of the printing material between the front blade 24 and the mask 8.

  The reason why the front blade 24 is made thinner and the rear blade 25 is made thick is that when printing on a mask 8 having a small opening or an uneven substrate, the rigidity of the front blade 24 is reduced to increase the follow-up property and ensure the mask. The printing material can be supplied to the opening. However, if the rigidity is low, the adhesion of the printing material to the substrate is lowered and the scraping force on the mask surface is also reduced. Therefore, by making the rigidity of the rear blade 25 larger than the rigidity of the front blade 24, the rear blade 25 ensures that the printing material in the opening is in close contact with the substrate, and the printing material remaining on the upper surface of the mask, particularly in the vicinity of the upper surface of the opening. This is because it can be surely removed to improve the separation of the plate and prevent chipping.

1 is a schematic diagram of an overall configuration of a printing machine to which the present invention is applied. It is sectional drawing which shows the structure of the squeegee part of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Main body frame, 3 ... Squeegee head, 5 ... Squeegee, 6 ... Elevating cylinder, 8 ... Mask, 9 ... Plate frame, 10 ... Printing table, 12 ... Substrate receiving conveyor, 13 ... Loading conveyor, 14 ... Unloading conveyor, DESCRIPTION OF SYMBOLS 15 ... Board | substrate, 16 ... Camera for mark recognition, 20 ... Squeegee cover, 21, 22 ... Blade pressing metal plate, 23 ... Spacer, 24 ... Front blade, 25 ... Rear blade.

Claims (2)

A printing table provided with an X-axis, Y-axis, and θ-axis moving mechanism and an elevating mechanism; a mask attached to a plate frame and having a transfer pattern as an opening; and a camera that images a positioning mark provided on the substrate and the mask; A squeegee head disposed on the upper side of the mask, for contacting the mask and supplying paste to the substrate surface, and a squeegee lifting mechanism and a horizontal movement mechanism for moving the squeegee up and down. In a screen printing machine equipped with
The squeegee has two steel blades sandwiched between resin spacers, the thickness of the rear blade is increased with respect to the thickness of the blade on the front side in the movement direction of the squeegee, and the front side A screen printing machine characterized in that the length of the rear side is set longer than the length of the blade. The screen printing machine according to claim 1, wherein
When the inclination before the blade exerts a pressing force on the mask is set to 50 to 70 degrees with respect to the mask surface, and the thickness of the front blade is 50 to 80 μm, the thickness of the rear blade is about 100 μm. A screen printer characterized by that.

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