JP2014200934A - Screen printer and screen printing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a screen printer and a screen printing method that can form a flat printed surface on a printed object with a dent part and print a fine pattern with high accuracy.SOLUTION: After a substrate 2 as a printed object is retained on a retaining table 12, upper surfaces of spacers 14, which are provided in the retaining table 12 and have the upper surfaces higher than the substrate 2 retained on the retaining table 12, are contacted with a mesh-like mask 13. Subsequently, after a paste pressing-out head 15 pressing out paste is contacted with the upper surface of the mask 13 contacted with the spacers 14, paste Pst is pressed out from the paste pressing-out head 15 to transcribe the paste Pst on the substrate 2 while sliding the paste pressing-out head 15 on the mask 13 without pushing down the mask 13.

Description

  An object of the present invention is to provide a screen printing machine and a screen printing method for transferring a paste to a printing material using a mesh-like mask.

  Conventionally, a gap type screen printing machine is known as a screen printing machine for transferring a paste to a substrate or other printed material. In this gap type screen printing machine, a photosensitive emulsion is applied to a mesh-like member made of metal fibers, and a mask (mesh-like mask) in which an opening is formed by printing a pattern on the photosensitive emulsion is formed above the printed material. After placing the paste on the mask and moving it while pressing the mask against the substrate with a squeegee, the paste is extruded from the opening of the mask into a pattern A paste having a corresponding shape is transferred onto the substrate. In the gap type screen printing machine, the squeegee pushes down the mask and advances on the substrate, and the mask is separated from the mask by the elastic restoring force of the mask itself immediately after the paste contacts the substrate and the paste is pushed out from the opening. The plate is released (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 2001-221935

  However, there is a limit to the amount of paste that can be pushed out of the mask opening by the squeegee, and when the substrate has a dent, if the dent is sufficiently filled with the paste, the flat printing surface on the substrate It was difficult to form. In addition, when the mask is pushed down by the squeegee, the mask opening moves in a direction parallel to the surface of the substrate to be printed, resulting in printing misalignment (print position misalignment). It was difficult to do.

  Accordingly, an object of the present invention is to provide a screen printing machine and a screen printing method capable of forming a flat printing surface on a printed material having a depression and printing a fine pattern with high accuracy.

  The screen printing machine according to claim 1, a holding table that holds a substrate, a spacer that is provided on the holding table and has a higher upper surface than the substrate that is held on the holding table, and an upper surface of the spacer A mesh-shaped mask that is in contact with the paste, a paste press-out head that presses out paste, and the paste press-out head is brought into contact with the upper surface of the mask in contact with the spacer, and then the mask is pressed down And a head moving means for sliding the paste pressing head on the mask, and a paste pressing means for pressing the paste from the paste pressing head while the paste pressing head slides on the mask. And with.

  A screen printing machine according to a second aspect of the present invention is the screen printing machine according to the first aspect, further comprising mask fixing and holding means for fixing and holding the mask in contact with the spacer on the spacer.

  According to a third aspect of the present invention, there is provided a screen printing method comprising: a holding step of holding a printing material on a holding table; and an upper surface of a spacer provided on the holding table and having a higher upper surface than the printing material held on the holding table. An abutting step for abutting on the mesh-shaped mask, and a paste extruding head for extruding the paste after contacting the upper surface of the mask abutting on the spacer and then pressing the paste without pressing down the mask And a transfer step of transferring the paste to the substrate by pressing the paste from the paste pressing head while sliding the head on the mask.

  In the present invention, since the paste is supplied onto the substrate by the paste pressing head, even if the substrate has a depression, the depression can be sufficiently filled with the paste, and a flat printing surface can be formed on the substrate. . Further, since the paste press-out head slides on the mask without pressing down the mask during the press-out of the paste, the mask remains in a non-deformable state and the opening formed in the mask does not move. For this reason, printing misalignment hardly occurs and a fine pattern can be printed with high accuracy.

The side view of the screen printer in one embodiment of the present invention The top view of the mask with which the screen printing machine in one embodiment of this invention is equipped The partial expanded side view of the screen printer in one embodiment of this invention The block diagram which shows the control system of the screen printer in one embodiment of this invention The side view of the screen printer in one embodiment of the present invention (A) (b) (c) The partial side view of the screen printer in one embodiment of this invention (A) (b) The partial expanded sectional view of the board | substrate with which the paste was printed by the screen printer in one embodiment of this invention

  Embodiments of the present invention will be described below with reference to the drawings. A screen printing machine 1 shown in FIG. 1 is a device that prints a paste Pst such as solder on the upper surface (printing surface 2 a) of a substrate 2 that is a printing object, and a moving table 11 that is movably provided with respect to a base 10. The holding table 12 is provided so as to be movable up and down. The holding table 12 is raised and lowered by driving the moving table 11, and the substrate 2 is held on the upper surface of the holding table 12. For convenience of explanation, the direction perpendicular to the paper surface of FIG. 1 is the X-axis direction, and the left-right direction of FIG. 1 is the Y-axis direction. Further, the vertical direction of the paper surface of FIG.

  Above the holding table 12, a mesh-like mask 13 having four sides supported by a rectangular mask frame 13W is installed in a horizontal posture. The mask 13 has a flat plate shape extending in the XY plane as shown in FIG. 2, and an opening 13h for defining the shape of the pattern for transferring the paste Pst to the printing surface 2a of the substrate 2 at the center. Is formed. The mask 13 is made of a mesh-like member made of metal fibers. After the photosensitive emulsion is applied to the mesh-like member, a photomask (pattern original) on which the pattern to be printed is drawn is brought into close contact with the photosensitive emulsion surface and exposed to printing. The opening 13h is formed by removing the portion of the photosensitive emulsion corresponding to the pattern.

  1, 2, and 3, a pair of spacers 14 are provided on the upper surface of the holding table 12 so as to be positioned at a position where the substrate 2 held by the holding table 12 is sandwiched in the Y-axis direction. The spacer 14 extends in the X-axis direction along the side of the substrate 2, and the upper surface thereof is higher than the printing surface 2 a of the substrate 2 held by the holding table 12 by an arbitrary distance Sd.

  In FIG. 1, a paste pressing head 15 is provided above a mask 13 so as to be movable by a head moving means 16. The head moving means 16 drives the first ball screw 16a extending in the Y-axis direction above the mask 13 by the first motor 16b, thereby moving the paste press-out head 15 in the horizontal direction and extending in the Z-axis direction. By driving the two-ball screw 16c by the second motor 16d, the paste pressing head 15 is moved in the vertical direction.

  In FIG. 1, the paste pressure head 15 accommodates the paste Pst therein, and has two blades 15a disposed at the lower end thereof so as to face each other in the Y-axis direction (that is, the movement direction of the paste pressure head 15). doing. The two blades 15a are inclined downward toward the lower portion of the center portion of the paste pressing head 15, and the tip portions thereof are close to each other and have a predetermined distance D in the horizontal direction (Y-axis direction). (FIG. 3).

  The paste pressure head 15 is provided with paste pressure means 15b such as a cylinder. The paste pressure head 15 pressures the paste Pst from between the two blades 15a by the operation of the paste pressure means 15b. .

  The moving table 11 raises the holding table 12 holding the substrate 2 so that the upper surfaces of the pair of spacers 14 abut against the lower surface of the mask 13. In this state, the distance between the lower surface of the mask 13 and the printing surface 2 a of the substrate 2 is a distance Sd between the upper surface of the spacer 14 and the printing surface 2 a of the substrate 2 held on the holding table 12.

  In FIG. 3, each spacer 14 is provided with suction holes 14 a that open to the upper surface (see also FIG. 2), and these suction holes 14 a are connected to a vacuum suction device 17 through a vacuum line 12 a in the holding table 12. Yes. By supplying a vacuum pressure from the vacuum suction device 17 to the suction holes 14a of the spacers 14 through the vacuum pipes 12a, suction force can be generated on the upper surface of the spacers 14, and the mask 13 abutted on the spacers 14 is sucked. Thus, the mask 13 can be fixed to the spacer 14. As described above, the vacuum suction device 17, the vacuum pipe line 12 a, and the suction hole 14 a constitute a mask fixing / holding means 20 that fixes and holds the mask 13 in contact with the spacer 14 to the spacer 14. The portion of the mask 13 in contact with the suction hole 14a is not a mesh region but a region hardened by a photosensitive emulsion that can be vacuum-sucked by the mask fixing and holding means 20.

  In FIG. 4, the lifting and lowering of the holding table 12 is performed by controlling the operation of the moving table 11 by the control device 30 provided in the screen printing machine 1. Is performed by controlling the operation of the head moving means 16. Further, the operation of extruding the paste Pst by the paste extruding head 15 is performed by the control device 30 controlling the operation of the paste extruding means 15b, and the mask 13 is fixed and held by the mask fixing and holding means 20 in a controlled manner. This is done by controlling the operation of the vacuum suction device 17 by the device 30.

  Next, a procedure (screen printing method) for printing the paste Pst on the substrate 2 by the screen printer 1 will be described. First, the control device 30 carries the substrate 2 supplied from the outside by carrying-in means (not shown) and holds it on the upper surface of the holding table 12 (holding step). Then, the movable table 11 is operated to raise the holding table 12 (arrow A shown in FIG. 5), and the upper surface of the spacer 14 is brought into contact with the lower surface of the mask 13 (contact process; FIG. 5). As a result, the mask 13 is placed at a position separated from the substrate 2 by the distance Sd.

  When the control device 30 brings the spacer 14 into contact with the mask 13, the control device 30 controls the operation of the vacuum suction device 17, sucks the mask 13 in contact with the upper surface of the spacer 14, and fixes and holds it on the spacer 14 (mask fixing and holding step). .

  When the control device 30 sucks the mask 13 and holds it fixed to the spacer 14, the control device 30 controls the operation of the head moving means 16 to bring the blade 15 a of the paste press-out head 15 into contact with the mask 13 above one of the spacers 14. (FIG. 6A. Arrow B shown in the figure). At this time, the blade 15 a is merely in contact with the mask 13 so that the blade 15 a does not press the mask 13 against the spacer 14.

  When the control device 30 brings the blade 15 a into contact with the mask 13 above the one spacer 14, the paste pressing head 15 slides on the mask 13 without pushing down the mask 13, The paste Pst is discharged to transfer the paste Pst to the substrate 2 (transfer process). Specifically, the control device 30 brings the blade 15 a into contact with the mask 13 above the one spacer 14, and then moves the paste pressing head 15 as it is in a direction parallel to the mask 13 (Y-axis direction). (Arrow C shown in FIG. 6B), the paste pressing means 15b is operated to control the paste Pst from between the two blades 15a of the paste pressing head 15, and the blade 15a When the position reaching the mask 13 is reached above the spacer 14, the movement of the paste pressing head 15 is stopped (FIG. 6C), and the pressing of the paste Pst from the paste pressing head 15 is stopped. .

  As described above, the screen printing machine 1 according to the present embodiment makes the paste press-out head 15 mask without pressing down the mask 13 after the paste press-out head 15 is brought into contact with the upper surface of the mask 13 in contact with the spacer 14. A head moving means 16 that slides on the mask 13, and a paste pressing means 15b that presses the paste Pst from the paste pressing head 15 while the paste pressing head 15 is moving on the mask 13. It has become.

  By the transfer step, the paste Pst discharged from the paste pressing head 15 passes through the mesh member in the opening 13 h of the mask 13 and is supplied to the printing surface 2 a of the substrate 2. For this reason, as shown in the enlarged view of FIG. 2, when the printing surface 2a of the substrate 2 has a depression 2b, a sufficient amount of paste Pst is also supplied into the depression 2b, and the depression 2b is sufficiently filled (FIG. 7A), and a flat printing surface 2c is formed on the substrate 2 (FIG. 7B).

  The paste pressing head 15 is moved in a direction parallel to the mask 13 while the blade 15a does not push the mask 13 downward and is simply in contact with the mask 13, and the spacer 14 causes the substrate 2 and the mask 13 to move. Since the mask 13 slides on the mask 13 while maintaining the distance Sd formed therebetween, the mask 13 is maintained in a state where it is not deformed (horizontal flat state) even during the movement of the paste press-out head 15, and the paste pressure is maintained. During the movement of the exit head 15, the opening 13h does not move. For this reason, printing misalignment hardly occurs and a fine pattern can be printed with high accuracy. Furthermore, since the mask 13 remains separated from the printing surface 2a of the substrate 2, bleeding and drooling that easily occurs when the plate is separated in a squeegee type screen printer are unlikely to occur.

  When the control device 30 executes the printing of the paste Pst on the substrate 2 by moving the paste pressing head 15 in the Y-axis direction as described above, the holding table 12 is released after releasing the fixed state of the mask 13 by suction. And the substrate 2 is unloaded from the screen printer 1 by unillustrated unloading means. Thereby, the screen printing per sheet of the substrate 2 is completed.

  As described above, in the screen printer 1 and the screen printing method according to the present embodiment, the paste Pst is supplied onto the substrate 2 by the paste pressing head 15, so that even if the substrate 2 has the recess 2 b, the recess The portion 2b can be sufficiently filled with the paste Pst, and a flat printing surface 2c can be formed on the substrate 2. Further, since the paste press-out head 15 slides on the mask 13 without pressing down the mask 13 during the press-out of the paste Pst, the mask 13 is kept in a non-deformed state, and the opening 13h formed in the mask 13 is maintained. Does not move. For this reason, printing misalignment hardly occurs and a fine pattern can be printed with high accuracy.

  Provided are a screen printing machine and a screen printing method capable of forming a flat printing surface on a printed material having a depression and printing a fine pattern with high accuracy.

1 Screen printer 2 Substrate (substrate)
12 Holding Table 13 Mask 14 Spacer 15 Paste Pressing Head 15b Paste Pressing Unit 16 Head Moving Unit 20 Mask Fixing Holding Unit Pst Paste

Claims (3)

A holding table for holding a substrate;
A spacer provided on the holding table and having a top surface higher than the substrate to be printed held on the holding table;
A mesh-like mask with which the upper surface of the spacer comes into contact;
A paste extruding head for extruding the paste;
A head moving means for sliding the paste pressing head on the mask without pressing down the mask after the paste pressing head is brought into contact with the upper surface of the mask in contact with the spacer;
A screen printing machine comprising paste pressing means for pressing the paste from the paste pressing head while the paste pressing head is sliding on the mask.   2. The screen printing machine according to claim 1, further comprising a mask fixing and holding means for fixing and holding the mask in contact with the spacer on the spacer. A holding step for holding the substrate on the holding table;
A contact step of contacting a mesh-shaped mask with an upper surface of a spacer provided on the holding table and having an upper surface higher than the printed material held on the holding table;
The paste pressing head for pressing the paste is brought into contact with the upper surface of the mask in contact with the spacer, and then the paste pressing head is slid on the mask without pressing down the mask. And a transfer step of transferring the paste to the substrate by pressing the paste from the press head.

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