JP2020011476A - Screen printing apparatus and screen printing method - Google Patents

Abstract

To provide a screen printing apparatus and a screen printing method capable of reliably removing paste attached to a mask.SOLUTION: A screen printing apparatus includes a mask cleaner which removes paste attached to a mask and a suction part which sucks the paste attached to the mask when the mask cleaner removes the paste. A mask cleaning method in the screen printing apparatus includes a printing process (ST1) of moving a squeegee on the mask and printing the paste onto a substrate through pattern holes, a first cleaning process (ST3) of removing the paste attached to a lower surface of the mask with the mask cleaner while performing suction by means of the suction part and a second cleaning process (ST5) of removing the paste attached to the lower surface of the mask by means of the mask cleaner while stopping the suction by means of the suction part.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a screen printing apparatus and a screen printing method for printing a paste on a substrate via a mask.

  The screen printing apparatus contacts the mask with the substrate and prints the paste on the substrate through the pattern holes formed in the mask. Such a screen printing apparatus is provided with a cleaning device for periodically scraping and cleaning the paste from the lower surface of the mask (for example, see Patent Document 1). The cleaning device of Patent Literature 1 includes a holding body that holds a plurality of scraping members that scrape the paste attached to the lower surface of the mask, and a suction unit that sucks the paste scraped by the scraping member. Then, the paste adhered to the mask is cleaned by sliding the scraping member into contact with the lower surface of the mask while sucking by the suction means.

JP 2016-196101 A

  However, in the cleaning device described in Patent Document 1, when the paste is removed while sliding, a part of the paste sucked out of the pattern hole by suction remains without being removed and remains on the lower surface of the mask. There was a problem that quality deteriorated.

  Therefore, an object of the present invention is to provide a screen printing apparatus and a screen printing method that can more reliably remove a paste attached to a mask.

  The screen printing apparatus of the present invention prints a mask having a pattern hole formed thereon and a paste supplied on the mask by sliding on the mask on a substrate positioned on the lower surface of the mask through the pattern hole. A squeegee, a mask cleaner for removing the paste attached to the lower surface of the mask, a suction unit for sucking the paste attached to the mask when the mask cleaner removes the paste, and the mask cleaner on the lower surface of the mask. A first cleaning operation of bringing the mask cleaner into contact with the mask and moving along the lower surface of the mask while suctioning the mask, and a state in which the mask cleaner is brought into contact with the lower surface of the mask and suction by the suction unit is stopped. And a control unit for executing a second cleaning operation of moving along the lower surface of the mask.

  According to the screen printing method of the present invention, a mask formed with a pattern hole and a paste supplied on the mask by sliding on the mask are printed on a substrate positioned on the lower surface of the mask through the pattern hole. A screen printing method in a screen printing apparatus, comprising: a squeegee; a mask cleaner for removing a paste attached to the lower surface of the mask; and a suction unit for sucking the paste attached to the mask when the mask cleaner removes the paste. A printing step of moving the squeegee on the mask to print the paste on the substrate through the pattern holes, and attaching the mask cleaner to the lower surface of the mask while sucking the paste by the suction unit. The first cleaning step of removing the paste and the suction by the suction unit were stopped. And a second cleaning step of removing the paste with the mask cleaner in state attached to the lower surface of the mask.

  According to the present invention, the paste attached to the mask can be more reliably removed.

FIG. 1 is a side view illustrating a configuration of a screen printing apparatus according to an embodiment of the present invention. FIG. 1 is a plan view illustrating a configuration of a screen printing apparatus according to an embodiment of the present invention. FIG. 1 is a structural explanatory diagram of a cleaning device provided in a screen printing device according to an embodiment of the present invention. 1 is a perspective view of a mask cleaner constituting a cleaning device provided in a screen printing apparatus according to an embodiment of the present invention. Flow chart of a screen printing method in a screen printing apparatus according to an embodiment of the present invention (A) (b) (c) Process explanatory view of mask cleaning in a screen printing apparatus according to an embodiment of the present invention

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. The configurations, shapes, and the like described below are examples for explanation, and can be appropriately changed according to the specifications of the screen printing device and the cleaning device. In the following, corresponding elements in all the drawings are denoted by the same reference numerals, and redundant description will be omitted. Hereinafter, the transfer direction of the substrate (the left-right direction in FIG. 2) is the X direction, the direction orthogonal to the X direction in the horizontal plane (the left-right direction in FIG. 1) is the Y direction, and the direction orthogonal to the horizontal plane (the vertical direction in FIG. Defined as Z direction.

  First, the structure of the screen printing apparatus 1 will be described with reference to FIGS. In FIG. 1, a substrate positioning unit 3 is provided on a base 2. The substrate positioning unit 3 is provided with an XY table 4, a θ table 5, and a substrate lifting / lowering mechanism 6 in this order from below. The XY table 4 moves the θ table 5 in a horizontal plane (X direction, Y direction). table 5 rotates the substrate lifting / lowering mechanism 6 around the Z axis by θ. A substrate holding unit 7 is provided above the substrate lifting mechanism 6. The substrate lifting / lowering mechanism 6 supports and lowers the substrate holding unit 7 from below.

  In FIG. 2, a pair of transport conveyors 8 extending in the X direction are installed on the base 2. The conveyor 8 conveys the substrate 9 received from the upstream side of the screen printing apparatus 1 in the X direction, and unloads it to the downstream side of the screen printing apparatus 1. The substrate holding unit 7 is installed near the center in the X direction of the transport conveyor 8. The substrate holding unit 7 receives the substrate 9 conveyed by the conveyor 8, clamps the side surface of the substrate 9 in the Y direction by a pair of clamp members 10 provided in the substrate holding unit 7, and holds the side at the clamp position.

  In FIG. 1, a control unit C is installed on the base 2. The control unit C controls the transport conveyor 8 to load and unload the substrate 9. The control unit C controls the substrate positioning unit 3 (XY table 4, θ table 5, substrate elevating mechanism 6) and substrate holding unit 7, and transfers the substrate 9 transported by the transport conveyor 8 to the vicinity of the center in the X direction. It is held by the holding unit 7.

  A mask 11 whose outer periphery is supported by a frame member 11w is disposed above the substrate holding unit 7. A plurality of pattern holes 11a for transferring (printing) paste such as cream solder are formed on the mask 11 corresponding to the shape and position of the electrodes 9a (see FIG. 2) to be printed on the substrate 9. I have. The paste is supplied onto the mask 11 by a paste supply mechanism (not shown).

  In FIG. 1, a print head 20 that is moved in the Y direction (arrow a1) by a print head moving mechanism (not shown) is provided above the mask 11. The print head 20 includes a moving base 21 that moves in the Y direction by a print head moving mechanism. Two squeegee holding portions 22 are arranged on the moving base 21 in a line in the Y direction. The squeegee holding unit 22 holds a squeegee 23 extending in the X direction at a lower end, and is moved up and down by a squeegee elevating mechanism 24 provided on the movable base 21 (arrow a2). The print head moving mechanism and the print head 20 are controlled by the control unit C.

  In FIG. 1, a camera head unit 25 and a cleaning device 30 are provided below the mask 11. In the present embodiment, the camera head unit 25 and the cleaning device 30 are mounted on the X-axis table 26 and move integrally in the Y direction (arrow a3). The camera head unit 25 includes a board recognition camera 25a for imaging the substrate 9 from above and a mask recognition camera 25b for imaging the mask 11 from the lower surface 11b. The camera head unit 25 can simultaneously recognize the substrate 9 and the mask 11 by moving in the horizontal direction.

  The board recognition camera 25a captures an image of the board-side mark 9m for alignment (see FIG. 2) formed on the board 9. The mask recognition camera 25b captures an image of a mask-side mark (not shown) for alignment formed on the mask 11. The imaging results of the board recognition camera 25a and the mask recognition camera 25b are transmitted to the control unit C.

  In FIG. 2, an X-axis table 26 is slidably connected to a Y-axis table 27 extending in the Y direction. The Y-axis table 27 includes a Y-axis moving mechanism (not shown) for horizontally moving the X-axis table 26 in the Y direction. The Y-axis moving mechanism is controlled by the control unit C. The control unit C moves the camera head unit 25 and the cleaning device 30 in the Y direction by controlling the Y-axis moving mechanism. For example, when the substrate 9 is brought into contact with the lower surface 11b of the mask 11 during screen printing, which will be described later, the camera head unit 25 and the cleaning device 30 move to a standby position beside the substrate holding unit 7 (see FIG. 1). At the time of mask cleaning, the camera head unit 25 and the cleaning device 30 move between the mask 11 and the substrate holding unit 7.

  Next, screen printing for transferring the paste to the substrate 9 through the pattern holes 11a of the mask 11 will be described. The screen printing is executed by the control unit C controlling each unit of the screen printing apparatus 1. First, the substrate holding unit 7 clamps and holds the substrate 9 transported by the transport conveyor 8. Next, the camera head unit 25 images the substrate-side mark 9m and the mask-side mark. Next, the substrate positioning unit 3 positions the substrate 9 with respect to the mask 11 based on the imaging result.

  Next, the substrate lifting / lowering mechanism 6 raises the substrate 9 together with the substrate holding unit 7 and makes the substrate 9 contact the lower surface 11b of the mask 11. Next, the squeegee elevating mechanism 24 lowers the squeegee 23 and comes into contact with the upper surface of the mask 11. Next, the print head moving mechanism slides the squeegee 23 on the mask 11 to transfer the paste supplied on the mask 11 to the substrate 9. As described above, the screen printing apparatus 1 slides the squeegee 23 on the mask 11 to print the paste supplied on the mask 11 on the substrate 9 positioned on the lower surface 11b of the mask 11 through the pattern holes 11a. Execute printing.

  Next, the configuration and function of the cleaning device 30 will be described with reference to FIGS. 3, 4, and 6. FIG. In FIG. 3, the cleaning device 30 includes a box-shaped cleaner mounting portion 31 mounted on the X-axis table 26 that moves in the Y direction. The cleaner mounting section 31 is provided with a cleaner lifting mechanism 32, and a mask cleaner 33 is mounted on an upper portion of the cleaner lifting mechanism 32. The cleaner lifting mechanism 32 is configured by an actuator driven by air or hydraulic pressure. The cleaner raising / lowering mechanism 32 is controlled by the controller C, and the mask cleaner 33 moves up and down by driving the cleaner raising / lowering mechanism 32 (arrow b).

  3 and 4, the mask cleaner 33 includes a substantially rectangular parallelepiped main body 34 having a cavity therein and extending in the X direction. A plurality (seven in this case) of blades 35 extending in the X direction are attached to the upper part of the main body 34 side by side in the Y direction. That is, the plurality of blades 35 are arranged in parallel with the moving direction of the mask cleaner 33. The blade 35 is a thin “spatial” flexible member formed of metal such as SUS or plastic. The blade 35 may be formed of an elastic material such as urethane rubber.

  FIG. 6A shows a cross section of the mask cleaner 33 viewed from the X direction. For convenience, the number of blades 35 of the mask cleaner 33 shown in FIG. 6A is simplified to four. The blade 35 is attached so as to protrude above the upper surface of the main body 34. When the blade 35 is in contact with the lower surface 11b of the mask 11, the attack angle θ of the blade 35 with respect to the horizontal lower surface 11 b of the mask 11 (between the lower surface 11 b of the mask 11 and the surface that scrapes the paste of the blade 35). The angle is smaller than 90 °, that is, an acute angle. That is, the blade 35 is inclined in a direction opposite to the moving direction (cleaning direction) of the mask cleaner 33.

  On the upper surface of the main body 34, a plurality of openings 36 are formed between the plurality of blades 35 and penetrate from the upper surface to the cavity 34a formed inside the main body 34. Further, a suction port 34b penetrating to the cavity 34a is formed on a side surface of the main body 34. One end of a pipe 37 is connected to the suction port 34b. In FIG. 3, the other end of the tube 37 is connected to a suction unit 38. The suction section 38 is controlled by the control section C, and the hollow section 34a of the main body section 34 is sucked by operating the suction section 38.

  In FIG. 6A, when the suction unit 38 operates while the blade 35 is in contact with the lower surface 11 b of the mask 11, the space S surrounded by the lower surface 11 b of the mask 11 and the blade 35 forms the opening 36 of the main body 34. Is sucked through. When the mask cleaner 33 is moved in the cleaning direction (right side in FIG. 6) in this state, the paste P attached to the mask 11 is sucked and removed by the mask cleaner 33 (see FIG. 6B).

  As described above, the mask cleaner 33 contacts the lower surface 11b of the mask 11 to scrape the paste P, and extends in the horizontal direction (X direction) intersecting with the cleaning direction (moving direction of the mask cleaner 33). Are arranged in the cleaning direction. Then, when the mask cleaner 33 removes the paste P, the suction unit 38 suctions the paste P attached to the mask 11 from the plurality of spaces S sandwiched by the blades 35.

  Next, a screen printing method in the screen printing apparatus 1 will be described with reference to FIG. In FIG. 5, first, the control unit C carries in the substrate 9 to be printed, aligns the substrate 9, and brings the substrate 9 into contact with the lower surface 11 b of the mask 11. Next, the control unit C moves the squeegee 23 on the mask 11 to print the paste P on the substrate 9 through the pattern holes 11a (ST1: printing step). Next, the control unit C lowers the substrate 9 to separate it from the lower surface 11b of the mask 11 and carries out the printed substrate 9.

  Next, the controller C moves the mask cleaner 33 from the standby position to a start position at which to start mask cleaning (ST2: first start position moving step). Next, the control unit C raises the mask cleaner 33 to bring the blade 35 (mask cleaner 33) into contact with the lower surface 11b of the mask 11 (arrow c in FIG. 6A). Next, the control unit C operates the suction unit 38 to execute a first cleaning operation of moving the mask cleaner 33 along the lower surface 11b of the mask 11 while suctioning by the suction unit 38 (FIG. 6B). .

  That is, the paste P adhered to the lower surface 11b of the mask 11 is removed by the mask cleaner 33 while sucking by the suction unit 38 (ST3: first cleaning step). As a result, the paste P attached to the pattern holes 11 a of the mask 11 is sucked out to the lower surface 11 b of the mask 11 and is sucked by the mask cleaner 33. In FIG. 6B, on the lower surface 11b of the mask 11 near the pattern hole 11a behind the moving mask cleaner 33 (the area indicated by the broken line d), the paste P sucked out of the pattern hole 11a by suction is applied. Are not completely absorbed by the mask cleaner 33, and some remain. This is because, during the first cleaning operation, the paste P of the pattern hole 11a keeps the paste P of the pattern hole 11a on the back surface (lower surface 11b) even after the blade 35 has passed the pattern hole 11a of the mask 11 due to the negative pressure of the suction unit 38. It is presumed that it is to move to.

  In FIG. 5, when the mask cleaner 33 moves to the stop position, the controller C lowers the mask cleaner 33 to separate the blade 35 from the lower surface 11b of the mask 11, and moves the mask cleaner 33 to the start position (ST4: second). Starting position moving step). Next, the control unit C raises the mask cleaner 33 to bring the blade 35 (mask cleaner 33) into contact with the lower surface 11b of the mask 11. Next, the control unit C performs a second cleaning operation of moving the mask cleaner 33 along the lower surface 11b of the mask 11 in a state where the suction by the suction unit 38 is stopped (FIG. 6C).

  That is, while the suction by the suction unit 38 is stopped, the paste P adhered to the lower surface 11b of the mask 11 is removed by the mask cleaner 33 (ST5: second cleaning step). In FIG. 6C, the paste P remaining without being removed by the first cleaning operation is scraped off by the plurality of blades 35 by the second cleaning operation, so that the mask P near the pattern hole 11a is removed. It is removed from the lower surface 11b (the area indicated by the broken line e). As described above, by performing the second cleaning operation after the first cleaning operation, the paste P can be more reliably removed from the lower surface 11b of the mask 11.

  In FIG. 5, when the mask cleaner 33 moves to the stop position, the controller C lowers the mask cleaner 33 to separate the blade 35 from the lower surface 11b of the mask 11, and moves the mask cleaner 33 to the standby position (ST6: standby position). Transfer process). Thus, a series of mask cleaning (ST2 to ST6) is completed, and then the process returns to the printing step (ST1) to start screen printing on the next substrate 9.

  Thus, after the first cleaning step (ST3) is performed between the printing step (ST1) and the next printing step (ST1) (during the printing step), the second cleaning step (ST5) is executed. Be executed. That is, the control unit C causes the second cleaning operation to be performed after the first cleaning operation is performed. Further, the control unit C determines that the moving speed (first moving speed v1) of the mask cleaner 33 in the first cleaning operation (first cleaning process) is equal to the mask speed in the second cleaning operation (second cleaning process). Control is performed so as to be lower than the moving speed of the cleaner 33 (second moving speed v2).

  Thereby, in the first cleaning operation, the paste P attached to the pattern holes 11a can be reliably sucked. In the second cleaning operation, by increasing the moving speed of the mask cleaner 33, the execution time of the mask cleaning can be reduced. The first moving speed v1 and the second moving speed v2 can be freely set according to the shape of the pattern hole 11a, the state of the paste P, the degree of attachment to the mask 11, and the like.

  In the mask cleaning method described above, the first cleaning step (ST3) and the second cleaning step (ST5) are each performed once, but the number of cleaning steps is not limited to this. There is no. For example, the second cleaning step (ST5) may be performed once after the first cleaning step (ST3) is performed twice. Further, the first cleaning step (ST3), the second cleaning step (ST5), the first cleaning step (ST3), the second cleaning step (ST5), and the cleaning step may be performed four times.

  In any method, the second cleaning step (ST5) is performed in the last cleaning step of mask cleaning, that is, the cleaning step immediately before moving to the next printing step (ST1). Accordingly, the paste P can be more reliably removed from the lower surface 11b of the mask 11, and the quality of screen printing can be improved.

  As described above, the screen printing apparatus 1 according to the present embodiment includes the mask 11 having the pattern holes 11a formed thereon and the paste P supplied on the mask 11 by sliding on the mask 11 through the pattern holes 11a. A squeegee 23 for printing on the substrate 9 positioned on the lower surface 11b of the mask 11, a mask cleaner 33 for removing the paste P adhered to the lower surface 11b of the mask 11, and a mask 11 for removing the paste P by the mask cleaner 33. First, the suction unit 38 for sucking the attached paste P and the mask cleaner 33 are brought into contact with the lower surface 11 b of the mask 11, and the mask cleaner 33 is moved along the lower surface 11 b of the mask 11 while being suctioned by the suction unit 38. In the cleaning operation, the mask cleaner 33 is brought into contact with the lower surface 11b of the mask 11, and the suction by the suction unit 38 is stopped. And and a control unit C to execute the second cleaning operation of moving along the lower surface 11b of the mask cleaner 33 mask 11 in a state of being.

  Thus, the paste P attached to the inside of the pattern hole 11a of the mask 11 and the lower surface 11b of the mask 11 can be removed more reliably.

  INDUSTRIAL APPLICABILITY The screen printing apparatus and the screen printing method of the present invention have an effect that paste attached to a mask can be more reliably removed, and are useful in the field of mounting components on a substrate.

DESCRIPTION OF SYMBOLS 1 Screen printing apparatus 9 Substrate 11 Mask 11a Pattern hole 11b Lower surface 23 Squeegee 33 Mask cleaner 35 Blade 38 Suction unit C Control unit P paste S Space v1 First moving speed (moving speed of mask cleaner in first cleaning operation)
v2 Second moving speed (moving speed of mask cleaner in second cleaning operation)
θ Attack angle (angle between the lower surface of the mask and the surface that scrapes the paste of the blade)

Claims (8)

A mask on which pattern holes are formed,
A squeegee that prints on the substrate positioned on the lower surface of the mask through the pattern holes the paste supplied on the mask by sliding on the mask,
A mask cleaner for removing paste attached to the lower surface of the mask,
When the mask cleaner removes the paste, a suction unit that suctions the paste attached to the mask,
A first cleaning operation of bringing the mask cleaner into contact with the lower surface of the mask, moving the mask cleaner along the lower surface of the mask while sucking by the suction unit, and contacting the mask cleaner with the lower surface of the mask; A screen printing apparatus, comprising: a control unit that executes a second cleaning operation of moving along the lower surface of the mask while suction by the suction unit is stopped.   The screen printing apparatus according to claim 1, wherein the control unit executes the second cleaning operation after executing the first cleaning operation. The mask cleaner has a state in which a plurality of blades extending in the horizontal direction intersecting with the moving direction of the mask cleaner that abuts on the lower surface of the mask and scrapes the paste are arranged in the moving direction,
The screen printing device according to claim 1, wherein the suction unit suctions the paste from a plurality of spaces sandwiched between the blades.   The screen printing apparatus according to claim 3, wherein an angle between a lower surface of the mask and a surface of the blade from which the paste is scraped is an acute angle.   The screen printing apparatus according to claim 1, wherein a moving speed of the mask cleaner in the first cleaning operation is lower than a moving speed of the mask cleaner in the second cleaning operation. A mask in which pattern holes are formed, a squeegee that slides on the mask and prints a paste supplied on the mask on a substrate positioned on the lower surface of the mask through the pattern holes, A screen printing method in a screen printing apparatus, comprising: a mask cleaner for removing the attached paste; and a suction unit for suctioning the paste attached to the mask when the mask cleaner removes the paste,
A printing step of printing the paste on the substrate through the pattern holes by moving the squeegee on the mask,
A first cleaning step of removing the paste adhering to the lower surface of the mask with the mask cleaner while sucking by the suction unit;
A second cleaning step of removing the paste adhering to the lower surface of the mask with the mask cleaner while the suction by the suction unit is stopped.   The screen printing method according to claim 6, wherein the second cleaning step is performed after the first cleaning step is performed between the printing step and the next printing step.   8. The screen printing method according to claim 6, wherein a moving speed of the mask cleaner in the first cleaning step is lower than a moving speed of the mask cleaner in the second cleaning step. 9.

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