Screen Printing Equipment

Abstract

To provide a screen printing apparatus that can prevent a situation where paste scraped away by cleaning work for a mask is made to adhere to the mask by a subsequent cleaning work.SOLUTION: A screen printing apparatus 1 is provided with a mask cleaning unit 21 that makes a blade 42 scrape away paste Pst made to adhere to a back side of a mask 13 when the paste Pst is filled thereinto by a printing head 18, and a blade cleaning unit 23 that cleans the blade 42. The blade cleaning unit 23 comprises: a wiping material 74 that contacts the blade 42; a wiping material moving mechanism 62 that moves the wiping material 74 to wipe the paste Pst scraped away by the blade 42; and a contact portion changing mechanism 90 that changes a portion that contacts the blade 42 of the wiping material 74 by rotating the wiping material 74 with an axis line crossing obliquely with respect to a direction that is orthogonal to an extending direction of the blade 42 as a center.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a screen printing apparatus that prints paste on a substrate using a mask in which predetermined openings are formed. [Background technology]

[0002] Conventionally, there is known a screen printing apparatus that prints paste on a substrate using a mask with predetermined openings. In such a screen printing apparatus, the openings of the mask are filled with paste using a squeegee, and then the substrate is separated from the mask (so-called plate separation). However, since the paste that has flowed from the openings remains on the underside of the mask after this plate separation, if the next printing operation is performed without any further processing, the paste may adhere to the top surface of a new substrate, resulting in the production of a defective substrate.

[0003] For this reason, Patent Document 1 below discloses a screen printing apparatus equipped with a cleaning device that removes paste adhering to the underside of the mask. This cleaning device includes multiple scraping members that slide along the underside of the mask in a cleaning direction to scrape off paste adhering to the underside of the mask, and a holder that holds these multiple scraping members. The multiple scraping members are held by the holder and aligned in series in the cleaning direction. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-196101 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the scraping member used to clean the mask still retains the paste scraped off the mask, and if the next mask is cleaned in this state, there is a risk that the paste that was on the scraping member will instead adhere to the mask.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a screen printing apparatus that can prevent paste scraped off during a mask cleaning operation from adhering to the mask during the next cleaning operation. [Means for solving the problem]

[0007] The screen printing apparatus of the present invention is a screen printing apparatus that prints paste on a substrate using a mask with predetermined openings formed therein, and comprises: a print head that fills the openings in the mask with paste when the substrate comes into contact with the mask, and prints the paste on the substrate; a mask cleaning means that uses a blade to scrape off paste that has adhered to the back surface of the mask due to the paste filling by the print head; and a blade cleaning means that wipes off the paste scraped off by the blade, and the blade cleaning means comprises: a wiping material that contacts the blade; a wiping material moving mechanism that moves the wiping material in a direction along the blade to wipe off the paste scraped off by the blade; and a contact part changing mechanism that changes the part of the wiping material that contacts the blade by rotating the wiping material around an axis that intersects obliquely with a direction perpendicular to the extension direction of the blade. [Effects of the Invention]

[0008] According to the present invention, it is possible to prevent the paste scraped off in a mask cleaning operation from adhering to the mask in the next cleaning operation. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a plan view of a screen printing apparatus according to an embodiment of the present invention. [Figure 2] 1 is a side view of a main part of a screen printing apparatus according to an embodiment of the present invention; [Figure 3] FIG. 1 is a plan view of a mask holding unit and a blade cleaning unit provided in a screen printing apparatus according to an embodiment of the present invention; [Figure 4] FIG. 1 is a plan view of a mask holding unit and a blade cleaning unit provided in a screen printing apparatus according to an embodiment of the present invention; [Figure 5] 1A and 1B are explanatory diagrams illustrating the operation of a screen printing apparatus according to an embodiment of the present invention. [Figure 6] 1A and 1B are explanatory diagrams illustrating the operation of a screen printing apparatus according to an embodiment of the present invention. [Figure 7] FIG. 1 is a perspective view of a mask cleaning unit provided in a screen printing apparatus according to an embodiment of the present invention; [Figure 8] FIG. 1 is a side view of a mask cleaning unit provided in a screen printing apparatus according to an embodiment of the present invention. [Figure 9] FIG. 1 is an explanatory diagram illustrating the operation of a screen printing apparatus according to an embodiment of the present invention. [Figure 10] 1A and 1B are explanatory views illustrating the operation of a mask cleaning unit provided in a screen printing apparatus according to an embodiment of the present invention. [Figure 11] 1 is a cross-sectional view of a mask cleaning unit provided in a screen printing apparatus according to an embodiment of the present invention; [Figure 12] FIG. 1 is a perspective view showing a part of a blade cleaning unit and a part of a blade cleaning unit holder provided in a screen printing apparatus according to an embodiment of the present invention. [Figure 13] FIG. 1 is a perspective view showing a part of a blade cleaning unit and a part of a blade cleaning unit holder provided in a screen printing apparatus according to an embodiment of the present invention. [Figure 14] FIG. 1 is a plan view showing a part of a blade cleaning unit and a part of a mask cleaning unit provided in a screen printing apparatus according to an embodiment of the present invention. [Figure 15] FIG. 1 is a side view of a portion of a blade cleaning unit provided in a screen printing apparatus according to an embodiment of the present invention. [Figure 16] FIG. 1 is a partial cross-sectional side view of a contact portion changing mechanism provided in a screen printing apparatus according to an embodiment of the present invention. [Figure 17] 1A and 1B are explanatory diagrams illustrating the operation of a contact portion changing mechanism provided in a screen printing apparatus according to an embodiment of the present invention. [Figure 18] 1A, 1B, and 1C are explanatory diagrams illustrating the operation of a contact portion changing mechanism provided in a screen printing apparatus according to an embodiment of the present invention. [Figure 19] 1A and 1B are a side view and a plan view showing a part of a squeegee cleaning unit provided in a screen printing apparatus according to an embodiment of the present invention, together with a part of a blade of a mask cleaning unit; [Figure 20] (a) (b) (c) Schematic explanatory diagrams showing an example of paste marks formed on the wiping surface of a wiping material provided in a screen printing device according to an embodiment of the present invention. [Figure 21] 1 is a process diagram of a screen printing method using a screen printing apparatus according to an embodiment of the present invention; [Figure 22] FIG. 10 is a view showing a state in which the state around the opening of the mask is imaged by a camera after the screen printing apparatus has performed plate separation in the embodiment of the present invention. [Figure 23] FIG. 10 is a diagram showing an example of an image obtained by capturing an image of the state around the opening of the mask with a camera after the screen printing apparatus has performed plate separation according to the embodiment of the present invention. [Figure 24] FIG. 10 is a plan view showing a part of a blade cleaning unit and a part of a mask cleaning unit included in a screen printing apparatus according to a first modified example of an embodiment of the present invention. [Figure 25] FIG. 10 is a plan view of a mask holding section and a blade cleaning unit holding section provided in a screen printing apparatus according to a second modified example of an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Figures 1 and 2 show a screen printing apparatus 1 according to one embodiment of the present invention. The screen printing apparatus 1 is a device that constitutes part of a component mounting line (not shown) that mounts components on a substrate KB to produce a mounted substrate, and repeatedly performs a task (screen printing operation) consisting of a series of operations: loading and positioning a substrate KB sent from outside the screen printing apparatus 1, printing a paste Pst such as solder on electrodes DK (Figure 2) provided on the upper surface of the substrate KB, and then carrying it out.

[0011] For ease of explanation in this embodiment, the transport (loading and unloading) direction of the substrate KB is referred to as the X direction (left-right direction as seen from the worker OP), the horizontal direction perpendicular to the X direction is referred to as the Y direction (front-rear direction as seen from the worker OP), and the up-down direction is referred to as the Z direction. Furthermore, within the Y direction (front-rear direction), the direction toward the back as seen from the worker OP (upper side of the paper in FIG. 1) is referred to as the front, and the direction toward the front as seen from the worker OP (lower side of the paper in FIG. 1) is referred to as the rear.

[0012] 1 and 2, the screen printing apparatus 1 includes a substrate transport unit 11, a substrate holding unit 12, a mask 13, a mask holding unit 14, a camera 15, a camera movement mechanism 16, a substrate holding unit movement mechanism 17, a print head 18, and a print head movement mechanism 19. The screen printing apparatus 1 further includes a mask cleaning unit 21, a mask cleaning unit movement mechanism 22, a blade cleaning unit 23, and a blade cleaning unit holding unit 24.

[0013] In Figure 1, the substrate transport unit 11 includes an upstream transport unit 11A and a downstream transport unit 11B. The upstream transport unit 11A and the downstream transport unit 11B are arranged side by side at positions spaced apart on either side of the substrate holding unit 12 in the X direction. The upstream transport unit 11A and the downstream transport unit 11B are arranged side by side in the Y direction and each comprise a pair of conveyors M that extend in the X direction, and the conveyors M are driven to transport the substrate KB in the X direction. The substrate transport unit 11 carries out the operation of carrying the substrate KB before the paste Pst is printed (the substrate KB on which the paste Pst will be printed) into the substrate holding unit 12 and the operation of carrying the substrate KB after the paste Pst has been printed out of the substrate holding unit 12.

[0014] Substrate holding unit 12 has the function of holding substrate KB carried in by substrate transport unit 11. Substrate holding unit 12 holds substrate KB in a horizontal position with electrodes DK facing upward (FIG. 2). Substrate holding unit 12 has a substrate movement mechanism (not shown) that moves substrate KB in the X direction, and this substrate movement mechanism moves substrate KB carried in from upstream transport unit 11A to a holding position and then ejects substrate KB from the holding position to downstream transport unit 11B.

[0015] 1, the mask 13 is made of a rectangular metal plate. The four sides of the mask 13 are supported by a mask frame 13W made of a rectangular frame. A plurality of openings 13K are formed in the center of the mask 13 and are arranged in accordance with the arrangement of the electrodes DK on the substrate KB.

[0016] 1, 3, and 4, the mask holding unit 14 includes two mask support guides 31 arranged side by side in the X direction and each extending in the Y direction, and four mask fixing units 32 installed on the two mask support guides 31. As shown in Fig. 1, two sides of the mask frame 13W extending in the Y direction are placed on the two mask support guides 31, thereby supporting the mask 13 in a horizontal position.

[0017] 1, four mask fixing parts 32 are arranged side by side in the Y direction, two on each of the two mask support guides 31. Each mask fixing part 32 is configured to fix to the mask support guide 31 by pressing a part of the mask frame 13W against the mask support guide 31 from above using a cylinder (not shown). Each mask fixing part 32 can be moved in the Y direction on the mask support guide 31 so that its position can be changed according to the size of the mask 13.

[0018] 2, camera 15 is provided at a height between substrate KB held by substrate holder 12 and mask 13. Camera 15 is capable of capturing both upper and lower images simultaneously or by switching between them. The images of the mask-side marks and substrate-side marks captured by camera 15 are processed in a control unit (not shown) provided in screen printing apparatus 1, and the relative position between mask 13 and substrate KB is calculated.

[0019] 1, camera movement mechanism 16 includes Y guide 16a extending in the Y direction outside mask holding unit 14, and X guide 16b extending in the X direction. One end of X guide 16b is attached to Y guide 16a and is movable along Y guide 16a. Camera 15 is attached to X guide 16b and is movable in the X direction along X guide 16b.

[0020] Camera movement mechanism 16 moves camera 15 in a horizontal plane (in the XY plane) in the area below mask 13 by moving X guide 16b in the Y direction relative to Y guide 16a (arrow A shown in FIG. 2) and by moving camera 15 in the X direction relative to X guide 16b. This allows camera 15 to move horizontally into the space between substrate KB and mask 13, and to capture images of both marks (not shown) provided on mask 13 (mask-side marks) and marks (not shown) provided on substrate KB (substrate-side marks) (FIG. 5(a)).

[0021] 2, substrate-holding-unit moving mechanism 17 moves substrate holding unit 12, which holds substrate KB, in the X, Y, and Z directions and in a rotational direction (θ direction) within the XY plane. Substrate-holding-unit moving mechanism 17 moves substrate holding unit 12 in the X, Y, and θ directions based on the relative position between mask 13 and substrate KB determined by the control unit, and raises substrate holding unit 12 while aligning substrate KB with mask 13. As a result, substrate holding unit 12 raises substrate KB and brings it into contact with the underside of mask 13 (FIG. 5(b)).

[0022] 1 and 2, the print head 18 comprises a head base 18a extending in the X direction and two squeegees 18b. The squeegee 18b is made of a plate-shaped member extending in the X direction. The two squeegees 18b face each other in the Y direction and are arranged so that the distance between them increases downward (FIG. 2). The two squeegees 18b can be raised and lowered independently of the head base 18a.

[0023] 2, the print head moving mechanism 19 moves the print head 18 in the Y direction (FIG. 5(b) → FIG. 6(a)), with the lower end of one squeegee 18b in contact with the upper surface of the mask 13. As a result, the print head 18 uses the squeegee 18b to scrape together the paste Pst on the mask 13, fills the openings 13K of the mask 13 with the paste Pst, and prints (applies) the paste Pst onto the electrodes DK of the substrate KB.

[0024] Once the openings 13K of the mask 13 are filled with the paste Pst, the substrate holder moving mechanism 17 lowers the substrate holder 12 to separate (detach) the substrate KB from the mask 13 (arrow B shown in FIG. 6(b)). Once the substrate KB has been detached from the mask 13, the substrate transport unit 11 ejects the substrate KB to the outside.

[0025] As described above, the screen printing apparatus 1 in this embodiment is configured to include a substrate holding unit 12 that holds the substrate KB that has been loaded, a substrate holding unit moving mechanism 17 that moves the substrate holding unit 12, a printing head 18 that fills the opening 13K of the mask 13 that the substrate KB is in contact with with the paste Pst and prints the paste Pst on the substrate KB, and a substrate transport unit 11 that loads the substrate KB onto which the paste will be printed, and after the paste Pst has been printed by the printing head 18, transports the substrate KB that has been separated from the mask 13 by the substrate holding unit moving mechanism 17.

[0026] The mask cleaning unit 21 functions as a mask cleaning means for scraping off the paste Pst adhering to the underside of the mask 13 after the mask has been released. As shown in FIG. 7, the mask cleaning unit 21 includes a blade holder 41 and a plurality (four in this example) of blades 42 held by the blade holder 41. The blade holder 41 includes a frame 41a that extends in the X direction as a whole and opens upward, and mask receiving portions 41b provided at both ends of the frame 41a in the X direction. The plurality of blades 42 are made of plate-like members that extend in the X direction and are held within the frame 41a in a state where they are aligned parallel to each other in the Y direction. In this embodiment, the blades 42 are made of resin and are members that have appropriate flexibility.

[0027] The mask contact surfaces 41T (FIG. 7), which are the upper surfaces of the two mask receiving portions 41b, are parallel to the horizontal plane and are located at a position relatively higher than the upper surface of the frame body 41a (FIG. 8). The blades 42 are held by the frame body 41a in an inclined position in which their upper edges (edges 42E) are tilted forward from a vertical position (a position parallel to the XZ plane) (FIGS. 7 and 8). In this state, the edges 42E of each blade 42 are located higher than the upper surfaces (mask contact surfaces 41T) of the two mask receiving portions 41b (FIG. 8).

[0028] The mask cleaning unit moving mechanism 22 functions as a mask cleaning means moving part that moves the mask cleaning unit 21 in the horizontal direction (Y direction) along the underside of the mask 13, and as shown in Fig. 1, it is equipped with a moving guide 22a that extends in the Y direction outside the X direction of the mask holding part 14, and a moving base 22b that extends in the X direction. The moving base 22b is supported by the moving guide 22a and is movable in the Y direction.

[0029] The mask cleaning unit 21 (more specifically, the frame 41a of the blade holder 41) is attached to the top of the movable base 22b. The movable base 22b has a space that communicates with the internal space of the frame 41a, and the air in the internal space of the frame 41a can be sucked in by the suction device 22S (FIG. 2) connected to the movable base 22b.

[0030] The movable base 22b (i.e., the mask cleaning unit 21) has a standby position at a position outside in the Y direction (specifically, rearward, toward the operator OP) of the mask holding part 14. When performing a cleaning operation (mask cleaning operation) in which the mask cleaning unit 21 scrapes off the paste Pst adhering to the underside of the mask 13, the mask cleaning unit moving mechanism 22 moves the mask cleaning unit 21 positioned at the standby position forward, and then reverses its direction to move the mask cleaning unit 21 backward (arrow C shown in FIG. 9).

[0031] When the mask cleaning unit 21 is moved rearward (FIG. 10(a) → FIG. 10(b)), the mask cleaning unit 21 brings the edge 42E of each of the four blades 42 into contact with the underside of the mask 13, and also brings the upper surface (mask abutment surface 41T) of each of the pair of mask receivers 41b into contact with the underside of the mask 13. Therefore, when the mask cleaning unit 21 is moved rearward by the mask cleaning unit moving mechanism 22, the four blades 42 slide over the underside of the mask 13, and scrape off the paste Pst adhering to the underside of the mask 13 with the edge 42E. While each blade 42 is in contact with the underside of the mask 13, it deforms so as to elastically bend in the direction opposite to the direction of travel (forward in this case), thereby maintaining the edge 42E in close contact with the underside of the mask 13 (FIG. 10(a) → FIG. 10(b)).

[0032] While the blade 42 is in contact with the lower surface of the mask 13 as described above, the pair of mask receiving portions 41b function as stoppers to prevent the blade 42 from being pressed against the mask 13 with excessive force. This keeps the elastic deformation of the blade 42 within a certain range, and controls the progress of wear of the blade 42 within an expected range.

[0033] While the mask cleaning unit 21 is using the blades 42 to scrape off the paste Pst adhering to the underside of the mask 13 (FIG. 10(a) → FIG. 10(b)), the air inside the frame 41a of the blade holder 41 is sucked in by the suction device 22S. As a result, the paste Pst adhering to the inside of the openings 13K of the mask 13 is sucked out from between the adjacent blades 42 (arrow D shown in FIGS. 10(a) and 10(b)), and the paste Pst adhering to the mask 13 is removed.

[0034] In this way, the mask cleaning unit 21 of this embodiment is configured to scrape off paste Pst adhering to the underside of the mask 13 by moving the upper edge (edge ​​42E) of the blade 42 in a horizontal direction (Y-axis direction) parallel to the mask 13 below the mask 13 while abutting the upper edge (edge ​​42E) of the blade 42 against the underside of the mask 13.

[0035] When the mask cleaning operation by the mask cleaning unit 21 is completed, the mask cleaning unit moving mechanism 22 returns the mask cleaning unit 21 to the standby position. After returning to the standby position, the mask cleaning unit 21 separates the edges 42E of each blade 42 and the pair of mask receiving portions 41b from the mask 13.

[0036] 11 shows the mask cleaning unit 21 in a state where the edge 42E of the blade 42 is separated from the lower surface of the mask 13 after the mask cleaning operation is completed. When separated from the mask 13, each blade 42 elastically returns to its original shape without deformation. The edge 42E of each blade 42 is positioned above the upper surfaces (mask contact surfaces 41T) of the two mask receiving portions 41b.

[0037] The blade cleaning unit 23 functions as a blade cleaning means that wipes away and cleans the paste Pst that the mask cleaning unit 21 has scraped off from the underside of the mask 13 by the blade 42 during the mask cleaning operation. For this reason, as shown in Figures 3 and 4, the blade cleaning unit 23 is located at a position corresponding to the standby position of the mask cleaning unit 21, that is, at a position outside the mask 13 in plan view (behind the area in the mask holding part 14 where the mask 13 is placed).

[0038] The blade cleaning unit holding portion 24 functions as a blade cleaning means holding portion that holds the blade cleaning unit 23 at a position (a position outside the mask 13 in a plan view) that corresponds to the standby position of the mask cleaning unit 21. For this reason, as shown in Figures 3 and 4, the blade cleaning unit holding portion 24 is provided in an area outside the mask 13 of the pair of mask support guides 31 that constitute the mask holding portion 14 (more specifically, an area behind the area where the mask 13 is placed in the mask holding portion 14).

[0039] 3 and 4, the blade cleaning unit holding portion 24 includes a partition portion 51, a pair of positioning portions 52, a pair of support portions 53, a pair of guide portions 54, and a pair of hook portions 55. The partition portion 51 is a member extending in the X direction, and both ends thereof are supported by a pair of mask support guides 31.

[0040] 3 and 4, a pair of positioning portions 52 are provided on the rear surface side of each end of partition portion 51. As also shown in Fig. 12, each of the pair of positioning portions 52 is made of a block-shaped member, and an engagement hole 52H is provided in a contact surface 52M, which is the rear surface.

[0041] 3, 12, and 13, each of the pair of support portions 53 has a shape that extends rearward from the partition portion 51. A guide surface 53M having a slope that gently rises from rear to front is formed on the upper surface of each support portion 53. In this embodiment, the guide portion 54 is made up of part of the mask support guide 31, and the guide surface 54M, which is the inner surface (the side where the pair of guide portions 54 face each other), is formed parallel to the YZ plane.

[0042] 3, 4, and 12, the pair of support parts 53 are made up of a part (parts rearward of the partition parts 51) of the pair of mask support guides 31 that constitute the mask holding part 14. That is, in this embodiment, the blade cleaning unit holding part 24 is configured to be integrated with the mask holding part 14. Therefore, a structure for attaching the blade cleaning unit holding part 24 to the mask holding part 14 can be omitted, and manufacturing costs can be reduced.

[0043] 3, 4 and 14, the blade cleaning unit 23 includes a wiping section 61, a wiping material moving mechanism 62, a pair of held sections 63 and a gear operating section 64. As shown in FIGS. 14 and 15, the wiping section 61 includes a base section 71, a holding section 72, a wiping material holder 73, a wiping material 74, a gear 75 and a torque limiter 76.

[0044] 14 and 15, base portion 71 is made of a plate-like member extending horizontally, and holding portion 72 is made of a block-like member. Holding portion 72 is positioned relative to base portion 71 by being brought into contact from the side with a plurality of positioning pins 71P (FIG. 14) erected on the upper surface of base portion 71, and in this state is fixed to base portion 71 by bolts 71B screwed into base portion 71 from above.

[0045] 14 and 15, the wiping material holder 73 has a rotating shaft 73a whose one end (rear end) is held by a holding portion 72, a disk-shaped base 73b provided on the other end (front end) of the rotating shaft 73a, and multiple holding rods 73c extending forward from the base 73b along the direction in which the rotating shaft 73a extends. The axis 73J of the rotating shaft 73a extends in a horizontal plane at an angle Θ from the direction (Y direction) perpendicular to the direction in which the blade 42 of the mask cleaning unit 21 extends (X direction) (FIG. 14). The wiping material 74 is made of, for example, a porous material and has a three-dimensional shape (cylindrical shape) with a circular circumferential surface (see FIG. 7).

[0046] The wiping material 74 is inserted through a plurality of holding rods 73c and is removably held in the wiping material holder 73. The gear 75 is fixed to the rotating shaft 73a and rotates integrally with the rotating shaft 73a around the axis 73J of the rotating shaft 73a. As shown in Figure 16 (Figure 16 is a view taken from the arrow V1-V1 shown in Figure 14), the gear 75 has many teeth (outer peripheral teeth 75T) on its outer periphery, and the outer peripheral teeth 75T are inclined with respect to the axis 73J of the rotating shaft 73a. That is, in this embodiment, the gear 75 is a helical gear, and the orientation of the outer peripheral teeth 75T (the ridges extending in the width direction) extends approximately parallel to the YZ plane (Figure 14).

[0047] 14 and 15, the torque limiter 76 is provided in the holder 72 and limits the torque transmitted by the rotating shaft 73a. In detail, when the torque acting on the rotating shaft 73a from the wiping material 74 or the gear 75 is equal to or less than a predetermined limit value (torque limit value), the torque limiter 76 allows the torque to be transmitted to the holder 72 (the rotation of the rotating shaft 73a is prevented), and when the torque acting on the rotating shaft 73a from the gear 75 exceeds the torque limit value, the torque is not transmitted to the holder 72 (the rotation of the rotating shaft 73a is permitted).

[0048] The wiping material moving mechanism 62 is a mechanism that extends in the X direction as a whole, and moves the wiping material 74 (directly the base part 71) in the X direction (arrow E shown in FIG. 7). This causes the wiping material 74 to move between an initial position (see the wiping material 74 shown by the solid line in FIG. 7) set at one end (here, the right end) of the blade 42 provided in the mask cleaning unit 21, and a maximum movement position (see the wiping part 61 shown by the dashed line in FIG. 7) set at the other end (here, the left end) of the blade 42.

[0049] 3 and 4, the pair of held parts 63 are provided to extend forward from both ends in the X direction of the wiping material moving mechanism 62. That is, the pair of held parts 63 are arranged at positions spaced apart in the wiping material moving direction (X direction), which is the moving direction of the wiping material 74 along the blade 42 provided in the mask cleaning unit 21.

[0050] 3, a protruding portion 63T that protrudes inward in the X direction (toward the opposing side of the pair of held portions 63) is formed at the front end of each of the pair of held portions 63. An engaging pin 63P protrudes forward from a contact surface 63M that is the front surface of the protruding portion 63T (see also FIGS. 12 and 14).

[0051] 3, 4 and 14, the gear operating part 64 is provided on one side (here, the right-side held part 63) of a pair of held parts 63 included in the blade cleaning unit 23. As shown in Fig. 16, the gear operating part 64 is configured to include a spring-loaded hinge 81, a spacer 82, and a gear contact member 83.

[0052] 14 and 16, one of the blades (fixed blade 81a) of hinge 81 is fixed in a horizontal position to the upper surface of held portion 63, and the other blade (movable blade 81b) is free to swing about the axis of shaft 81c extending in the Y direction. Spacer 82 is attached to the underside of movable blade 81b of hinge 81, and the base end side (right end side in FIG. 16) of gear contact member 83 is attached to spacer 82. Therefore, gear contact member 83 swings (rises and falls) integrally with spacer 82 and movable blade 81b, with the axis of shaft 81c as a fulcrum.

[0053] The spacer 82 limits the range of elevation of the movable-side wing portion 81b (and therefore the gear contact member 83) so that the gear contact member 83 does not fall beyond the horizontal position. As a result, when no upward force is acting on the tip end 83T of the gear contact member 83, the spacer 82 abuts against the held portion 63, and the gear contact member 83 assumes a horizontal position, as shown in Fig. 16, and is positioned on the same plane as the fixed-side wing portion 81a. When an upward force acts on the tip end 83T of the gear contact member 83 in the horizontal position, the movable-side wing portion 81b rises up and down around the axis of the shaft portion 81c (in the direction of raising the tip end 83T), but when the pressing force is removed, the movable-side wing portion 81b returns to its original horizontal position due to the biasing force of the biasing spring.

[0054] 14 and 16, the gear contact member 83 has an opening 83K that penetrates in the Z direction (thickness direction of the gear contact member 83). When the wiping material 74 is in the initial position (FIG. 14), one of the outer teeth 75T of the gear 75 engages with the opening 83K from below (see also FIG. 16). The opening 83K has a substantially rectangular shape in a plan view, and of the two sides facing each other in the X direction, the left side is oriented in the Y direction, i.e., substantially coincides with the orientation of the outer teeth 75T of the gear 75, which is a helical gear.

[0055] 14, when the wiping material 74 is in the initial position and one of the outer teeth 75T of the gear 75 is inserted into the opening 83K of the gear contact member 83 from below (FIG. 16), the gear contact member 83 is not subjected to an upward pushing force from the gear 75. Therefore, when the wiping material 74 is in the initial position, the movable-side blade portion 81b of the hinge 81 is located on the same plane as the fixed-side blade portion 81a.

[0056] Here, when the wiping material 74 moves from the initial position toward the maximum movement position (FIG. 17(a) → FIG. 17(b)), the outer peripheral teeth 75T that had entered the opening 83K receive a force from the gear contact member 83, which is in a horizontal position, in a direction that hinders its movement (here, to the right). However, at this time, the outer peripheral teeth 75T that had entered the opening 83K of the gear contact member 83 push up (raise) the tip end 83T of the gear contact member 83 and leave the opening 83K, so the gear 75 moves toward the maximum movement position without being rotated by the gear contact member 83 (arrow F shown in FIG. 17(b)).

[0057] On the other hand, when the wiping member 74 that has moved from the maximum movement position returns to the initial position (Fig. 18(a) → Fig. 18(b) → Fig. 18(c)), in the process of its return, one of the outer peripheral teeth 75T of the gear 75 abuts on the tip 83T of the gear contact member 83 from the side (here, the left side). At this time, the outer peripheral tooth 75T presses the gear contact member 83 in the falling direction (the direction of lowering the tip 83T), but the gear contact member 83 does not displace in the falling direction and supports the horizontal posture because of the spacer 82. Therefore, a large reaction force G (Fig. 18(b)) from the gear contact member 83 acts on the outer peripheral tooth 75T.

[0058] The torque limit value (T0) set for the torque limiter 76 is set to a value smaller than the torque (T1) acting on the gear 75 (i.e., the rotary shaft 73a) by the reaction force G (T0 < T1). For this reason, the rotary shaft 73a rotates around the axis 73J together with the gear 75 (arrow R shown in Fig. 18(c)). At this time, the angle of the rotating rotary shaft 73a is the angle corresponding to one of the outer peripheral teeth 75T of the gear 75, and the wiping member 74 also rotates around the axis 73J of the rotary shaft 73a by the angle corresponding to one of the outer peripheral teeth 75T of the gear 75.

[0059] When mounting the blade cleaning unit 23 with such a configuration on the blade cleaning unit holding portion 24, the pair of protruding portions 63T provided in the blade cleaning unit 23 are placed on the pair of support portions 53 (guide surfaces 53M) provided in the blade cleaning unit holding portion 24. And in that state, the whole of the blade cleaning unit 23 is moved forward.

[0060] When the blade cleaning unit 23 is moved forward, the pair of engagement pins 63P of the blade cleaning unit 23 enter the pair of engagement holes 52H of the blade cleaning unit holding portion 24, and the contact surfaces 63M of each of the pair of protruding portions 63T abut on the contact surfaces 52M of each of the pair of positioning portions 52 (Fig. 3 → Fig. 4 and Fig. 12 → Fig. 13). Thereby, the blade cleaning unit 23 is positioned in the Y direction with respect to the blade cleaning unit holding portion 24. <(

[0061] Before the abutment surfaces 63M of the pair of protrusions 63T abut against the abutment surfaces 52M of the pair of positioning parts 52, the lower surfaces of the pair of held parts 63 (protrusions 63T) of the blade cleaning unit 23 are guided by the pair of support parts 53 (guide surfaces 53M) of the blade cleaning unit holding part 24, and the pair of held parts 63 (protrusions 63T) are positioned in the Z direction relative to the blade cleaning unit holding part 24. In addition, the side surfaces of the pair of held parts 63 (protrusions 63T) are guided by the pair of guiding parts 54 (guide surfaces 54M) of the blade cleaning unit holding part 24, and the pair of held parts 63 (protrusions 63T) are positioned in the X direction.

[0062] The pair of protrusions 63T of the blade cleaning unit 23 come into contact with the inclined surfaces 55M (FIG. 12) of the pair of hooks 55 provided on the blade cleaning unit holding part 24, elastically pressing down the hooks 55, before the abutment surfaces 63M come into contact with the pair of abutment surfaces 52M of the blade cleaning unit holding part 24. Then, when the lower surfaces of the protrusions 63T have passed over the inclined surfaces 55M at the timing when the abutment surfaces 63M come into contact with the abutment surfaces 52M, the hooks 55 are released from being pressed down by the protrusions 63T and return to their original position.

[0063] The hook portion 55, which has returned to its original position, engages with the back surface 63N (FIGS. 3 and 12) of the protrusion 63T (FIGS. 12 → 13). This causes the blade cleaning unit 23 to be held (fixed) in the blade cleaning unit holding portion 24. When the blade cleaning unit 23 is held in the blade cleaning unit holding portion 24, the wiping material 74 of the wiping portion 61 provided in the blade cleaning unit 23 is positioned above the mask cleaning unit 21, which is positioned in the standby position (FIGS. 1 and 2).

[0064] As described above, the blade cleaning unit 23 provided in the screen printing apparatus 1 in this embodiment is configured to include a wiping material 74 that contacts the blade 42 provided in the mask cleaning unit 21, a wiping material moving mechanism 62 that moves the wiping material 74 in a direction along the edge 42E of the blade 42 (X direction) to wipe off the paste Pst scraped off by the blade 42, and a pair of held parts 63 that are arranged at positions spaced apart in the direction along the blade 42 (X direction) and held by the blade cleaning unit holding part 24. The blade cleaning unit 23 is moved in a direction (Y direction) perpendicular to the direction along the blade 42 (X direction) to be attached (held) to the blade cleaning unit holding part, and the blade cleaning unit holding part 24 is configured to include a pair of support parts 53 that support the lower surfaces of the pair of held parts 63 (more specifically, a pair of protrusions 63T) when the blade cleaning unit 23 is attached, and a pair of guide parts 54 that guide the side surfaces of the held parts 63 that move on the support parts 53.

[0065] To remove the blade cleaning unit 23 held by the blade cleaning unit holding portion 24, simply pull the blade cleaning unit 23 rearward while pressing down the pair of hook portions 55. In this way, the screen printing apparatus 1 of this embodiment makes it easy to attach and detach the blade cleaning unit 23 to and from the blade cleaning unit holding portion 24.

[0066] As described above, the screen printing apparatus 1 in this embodiment is provided with the blade cleaning unit holding part 24 that detachably holds the blade cleaning unit 23 that wipes off the paste Pst scraped off by the blade 42, and the blade cleaning unit 23 can be easily removed from the blade cleaning unit holding part 24, so that the blade cleaning unit 23 does not interfere with maintenance, inspection, etc. of the screen printing apparatus 1. Furthermore, since the pair of held parts 63 are supported by the pair of support parts 53, the blade cleaning unit 23 can be stably held by the blade cleaning unit holding part 24.

[0067] When the blade cleaning unit 23 performs an operation of wiping off the paste Pst adhering to the edges 42E of each blade 42 of the mask cleaning unit 21 after the mask cleaning operation (blade cleaning operation), the wiping member moving mechanism 62 moves the wiping part 61, which is located in the initial position, toward the maximum movement position. As a result, the wiping member 74 moves in the X direction, i.e., in the extension direction of each blade 42, while contacting the edges 42E of each of the four blades 42, and slides over the edges 42E to wipe off the paste Pst that each blade 42 has scraped off from the underside of the mask 13.

[0068] While the wiping material 74 slides over the edge 42E of the blade 42, the wiping material 74 wipes away the paste Pst using a wiping surface 74M, which is a surface within a certain range of the circumferential surface of the wiping material 74 centered on a projection line TS, which is a projection of the axis 73J onto the circumferential surface, as shown in Figures 19(a) and 19(b) (Figure 19(b) is a view from the arrow V2-V2 shown in Figure 19(a)). In this embodiment, since the mask cleaning unit 21 has four blades 42, the traces of the paste Pst wiped off by the wiping material 74 from the four blades 42 are four parallel lines (Figure 19(b)). The extension direction of these four parallel lines of the paste Pst is parallel to the extension direction of the blade 42 (Y direction) and is tilted at an angle Θ from the axis 73J (projection line TS) of the rotation shaft 73a in a plan view.

[0069] As described above, in order for the wiping material 74 to slide on the edge 42E of the blade 42, the wiping material 74 must not rotate together with the rotating shaft 73a, and it is necessary to prevent the rotating shaft 73a from rotating. For this reason, the torque limit value (T0) set in the torque limiter 76 is set to a value greater than the torque (T2) acting on the rotating shaft 73a when the wiping surface 74M of the wiping material 74 receives a drag force from the blade 42 during the blade cleaning operation (when the wiping material 74 moves) (T2 <T0)。

[0070] Thus, in this embodiment, a torque limiter 76 for limiting the torque transmitted by the rotating shaft 73a is provided. By this torque limiter 76, when the wiping material 74 moves along the blade 42 by the wiping material moving mechanism 62, the rotation of the rotating shaft 73a is blocked, and when the wiping material moving mechanism 62 moves the wiping material holder 73 to bring the gear 75 into contact with the gear contact member 83, the rotation of the rotating shaft 73a is allowed. Therefore, the torque limit value (T0) in the torque limiter 76, the torque (T1) acting on the rotating shaft 73a by the reaction force G (Fig. 18(b)) received by one of the outer peripheral teeth 75T of the gear 75 from the tip 83T of the gear contact member 83 during the process of the wiping material 74 located on the side of the maximum movement position moving to the side of the initial position, and the torque (T2) received by the rotating shaft 73a due to the resistance force received by the wiping material 74 from the blade 42 during the blade cleaning operation have a relationship of T2 < T0 < T1.

[0071] In this embodiment, as described above, since the torque limit value (T0) in the torque limiter 76 is set to a value larger than the torque (T2) received by the rotating shaft 73a due to the resistance force received by the wiping material 74 from the blade 42 during the blade cleaning operation (T2 < T0), the rotating shaft 73a does not rotate regardless of whether the wiping material 74 is moved in either direction in the extending direction (X direction) of the blade 42. Therefore, in the blade cleaning operation, the blade cleaning unit 23 can wipe the paste Pst from the blade 42 with the wiping material 74 not only on the path (forward path) from the initial position to the maximum movement position but also on the path (return path) from the maximum movement position to the initial position, and on both the forward path and the return path.

[0072] Thus, in the screen printing apparatus 1 according to this embodiment, since the paste Pst attached to the blade 42 of the mask cleaning unit 21 is wiped off, it is possible to prevent a situation where the paste scraped off by the mask cleaning unit 21 during the cleaning operation of the mask 13 adheres to the mask 13 in the next cleaning operation.

[0073] In this embodiment, the gear 75 constituting the wiping unit 61 is not rotated by the gear contact member 83 during the forward movement in which the wiping material moving mechanism 62 moves the wiping material 74 from the initial position to the maximum movement position (FIG. 17(a) → FIG. 17(b)), but is rotated by the reaction force G received from the gear contact member 83 when the outer peripheral tooth 75T of the gear 75 abuts against the gear contact member 83 during the backward movement in which the wiping material 74 moves from the maximum movement position to the initial position (FIG. 18(a) → FIG. 18(b) → FIG. 18(c)). At this time, the gear 75 rotates by the distance of one outer peripheral tooth 75T, so that the wiping surface 74M of the wiping material 74 moves on the circumferential surface of the wiping material 74 by a distance L equivalent to one outer peripheral tooth 75T, and the wiping surface 74M of the wiping material 74 is changed.

[0074] As described above, the blade cleaning unit 23 provided in the screen printing apparatus 1 in this embodiment is configured to include a wiping material holder 73 having a rotation shaft 73a that rotates about an axis 73J and that holds a cylindrical (three-dimensional shape with a circumferential surface) wiping material 74, a gear 75 provided on the wiping material holder 73, and a gear contact member 83 that is positioned so as to be able to come into contact with the gear 75 within the movement range (here, the range between the initial position and the maximum movement position) of the wiping material holder 73. When the wiping material moving mechanism 62 moves the wiping material holder 73 and the gear 75 comes into contact with the gear contact member 83, the wiping material holder 73 rotates about the axis 73J to change the wiping surface 74M.

[0075] In this embodiment, the portion of the wiping material 74 that comes into contact with the blade 42 (wiping surface 74M) can be changed by the simple action of rotating the wiping material holder 73 about the axis 73J, which simplifies the configuration. Furthermore, since a dedicated power source (such as a motor or cylinder) is not required just for rotating the wiping material holder 73, the device configuration can be simplified.

[0076] In this embodiment, the wiping material holder 73, gear 75 and gear contact member 83 constitute a contact part changing mechanism 90 that changes the part of the wiping material 74 that comes into contact with the blade 42 (wiping surface 74M) by rotating the wiping material 74 around an axis 73J that intersects obliquely with a direction (Y direction) perpendicular to the direction in which the blade 42 extends (X direction).

[0077] 20(a), (b), and (c) are schematic diagrams showing traces of the paste Pst formed on the wiping surface 74M of the wiping material 74 when the gear 75 is rotated by one outer peripheral tooth 75T at a time by the gear contact member 83. Fig. 20(b) shows a state in which the wiping surface 74M has moved a distance L equivalent to one outer peripheral tooth 75T from the state in Fig. 20(a), and Fig. 20(c) shows a state in which the wiping surface 74M has moved a distance 5L (L × 5) equivalent to five outer peripheral teeth 75T from the state in Fig. 20(a).

[0078] 20(a), (b), and (c), the direction in which the traces of the paste Pst extend on the wiping surface 74M is inclined with respect to a direction perpendicular to a projection line TS obtained by projecting the axis 73J of the rotation shaft 73a onto the circumferential surface of the wiping material 74. For this reason, even if a certain wiping surface 74M and a wiping surface 74M moved a distance L equivalent to one outer peripheral tooth 75T overlap in part (end portion), the trace of the paste Pst on the certain wiping surface 74M and the paste Pst on the wiping surface 74M moved by the distance L do not overlap in the end region TR (FIGS. 20(b) and 20(c)).

[0079] This effect is obtained by the fact that the wiping material 74 has a three-dimensional shape (cylindrical shape) with a circumferential surface centered on the axis 73J, and is configured so that the wiping surface 74M with the blade 42 can be changed by rotating around the axis 73J, and also because the axis 73J of the rotation shaft 73a is inclined horizontally from the direction (Y direction) perpendicular to the direction in which the blade 42 extends (X direction).

[0080] Next, we will explain the flow of the screen printing operation (screen printing method) performed by the screen printing apparatus 1. As shown in Fig. 21, the screen printing method using the screen printing apparatus 1 involves performing a substrate loading step, a contact step, a printing step, a plate releasing step, and a substrate unloading step in this order, and simultaneously performing a mask cleaning step and a blade cleaning step in this order.

[0081] The substrate carrying-in process is a process of carrying in a substrate KB onto which the paste Pst will be printed, and is performed by the substrate transport unit 11 transporting (carrying in) the substrate KB supplied from outside the screen printing apparatus 1. The contacting process is a process of performing a contacting operation of aligning the substrate KB carried in in the substrate carrying-in process with the mask 13 and bringing it into contact with the underside of the mask 13, and is performed by the substrate holder moving mechanism 17 bringing the substrate KB into contact with the underside of the mask 13.

[0082] The printing process is a process of filling the openings 13K of the mask 13 with which the substrate KB has been brought into contact in the contacting process with paste Pst, and printing the paste Pst on the substrate KB, and is carried out by filling the openings 13K of the mask 13 with which the substrate KB has been brought into contact with the paste Pst using the print head 18. The plate releasing process is a process of performing a plate releasing operation to separate the substrate KB from the mask 13 after the printing process, and is carried out by separating the substrate KB on which the paste Pst has been printed from the mask 13 using the substrate holder moving mechanism 17. The substrate carrying-out process is a process of performing a substrate carrying-out operation to remove the substrate KB after the printing process has been carried out, and is carried out by the substrate transport unit 11 transporting the substrate KB to the outside of the screen printing apparatus 1.

[0083] The mask cleaning process is a process of performing a mask cleaning operation in which the paste Pst adhering to the underside of the mask 13 during the printing process is scraped off by the blade 42 of the mask cleaning unit 21, and is carried out by moving the mask cleaning unit 21 under the mask 13 by the mask cleaning unit moving mechanism 22. The blade cleaning process is a process of performing a blade cleaning operation in which the blade 42 that scraped off the paste Pst from the underside of the mask 13 during the mask cleaning process is cleaned by the blade cleaning unit 23, and is carried out by the blade cleaning unit 23 moving the wiping material 74 in the extension direction of the blade 42 by the wiping material moving mechanism 62.

[0084] Of the substrate loading step, printing step, substrate unloading step, mask cleaning step, and blade cleaning step that constitute the screen printing method of this embodiment, the substrate loading step, printing step, and substrate unloading step are performed in this order for each substrate KB on which the paste Pst is to be printed. The mask cleaning step is performed by bringing the blade 42 into contact with the mask 13, and therefore cannot be performed while the printing step is being performed (nor can it be performed while the blade cleaning step is being performed). Therefore, if the mask cleaning work is performed each time printing of the paste Pst is completed for one substrate KB, as shown in FIG. 21, the mask cleaning work is performed after the mask release work (step) is completed and before the next contact work (step) begins (between the start of unloading the substrate KB and the completion of loading the next substrate KB).

[0085] Furthermore, because the blade cleaning work is an operation (step) for cleaning the blade 42 of the mask cleaning unit 21 that scraped off the paste Pst from the underside of the mask 13 in the mask cleaning process, it cannot be performed while the mask cleaning work is being performed, and is started after the mask cleaning work is completed. The blade cleaning work can be performed at any time other than while the mask cleaning work is being performed, but if the mask cleaning work (step) and blade cleaning work (fixing) are performed each time printing of the paste Pst is completed for one substrate KB, the blade cleaning work (step) is completed between the end of the mask cleaning work and the end of the next plate release work (step), as shown in Figure 21.

[0086] In this way, if the mask cleaning work (step) is performed after the plate release work (step) is completed and before the next contact work (step) is started, and the blade cleaning work (step) is completed between the end of the mask cleaning work and the end of the next plate release work (step), not only does it not need to be stopped for the mask cleaning work, but it also does not need to be stopped for the blade cleaning work (step). Thus, according to the screen printing apparatus 1 (screen printing method) of this embodiment, it is possible to prevent a decrease in productivity of the screen printing apparatus 1 (and thus the component mounting line), while also preventing a situation in which the paste Pst scraped off in the cleaning work of the mask 13 adheres to the next mask 13.

[0087] In the above explanation, the mask cleaning work is performed each time printing of the paste Pst is completed for one substrate KB. However, the mask cleaning work (step) does not have to be performed each time printing is completed for one substrate KB, and may be performed after printing several substrates KB. Alternatively, as shown in FIG. 22, the underside of the mask 13 immediately after the completion of mask separation is imaged by the camera 15, and the adhesion state of the paste Pst in the opening 13K is examined based on the image GZ (FIG. 23) obtained thereby. Then, as shown in FIG. 23, if a bleeding portion NJ or a clogged portion TM is found in the opening 13K of the mask 13, the mask cleaning work may be performed as an opportunity, followed by the blade cleaning work.

[0088] (First Modification) A first modification of this embodiment is shown. In the first modification, as shown in Fig. 24, the gear 75 of the blade cleaning unit 23 is a spur gear instead of a helical gear. Also, the opening 83K of the gear contact member 83 is trapezoidal in plan view, and the left side of the two sides facing in the X direction is oriented obliquely so as to substantially coincide with the orientation of the outer teeth 75T of the gear 75. Even with this configuration, when the wiping material moving mechanism 62 moves the wiping material holder 73 and the gear 75 comes into contact with the gear contact member 83, the wiping material holder 73 rotates around the axis 73J of the rotation shaft 73a, thereby achieving the same effect as the above-described embodiment.

[0089] (Second Modification) Next, a second modified example of this embodiment will be described. In this second modified example, as shown in Fig. 25, the blade cleaning unit holding portion 24 is a separate member from the mask holding portion 14. That is, in this second modified example, the pair of guide portions 54 extending rearward from the partition portion 51 are not part of the pair of mask support guides 31, but are separate members from the pair of mask support guides. A configuration in which the blade cleaning unit holding portion 24 is a separate member from the mask holding portion 14, as in this second modified example, is extremely useful when the distance in the Y direction between the pair of mask support guides 31 can be changed to match the size of the substrate KB (see arrow H in Fig. 25).

[0090] As described above, the screen printing apparatus 1 in this embodiment is equipped with a blade cleaning means (blade cleaning unit 23) that wipes off the paste Pst adhering to the blade 42 of the mask cleaning unit 21, thereby preventing the paste Pst scraped off by the mask cleaning unit 21 during the cleaning operation of the mask 13 from adhering to the mask 13 during the next cleaning operation.

[0091] Furthermore, in the screen printing apparatus 1 of this embodiment, the portion of the wiping material 74 that comes into contact with the blade 42 (wiping surface 74M) can be changed by rotating the apparatus around an axis 73J that intersects obliquely with the direction (Y direction) perpendicular to the direction in which the blade 42 extends (X direction), and a wide area of ​​the wiping material 74 can be used to clean the blade, thereby reducing the frequency with which the wiping material 74 needs to be replaced and reducing maintenance costs.

[0092] Although the embodiments of the present invention have been described above, the present invention is not limited to the above and various modifications are possible. For example, in the above-described embodiments, the wiping material 74 has a three-dimensional shape (cylindrical shape) with a circumferential surface, but this is only an example and the shape of the wiping material 74 is not limited. [Industrial Applicability]

[0093] To provide a screen printing device capable of preventing a situation in which paste scraped off in a mask cleaning operation is attached to the mask in the next cleaning operation. [Explanation of symbols]

[0094] 1 Screen printing equipment 13 Mask 13K aperture 17 Board holder moving mechanism 18 print heads 21 Mask cleaning unit (mask cleaning means) 23 Blade cleaning unit (blade cleaning means) 24 Blade cleaning unit holder 42 Blades 61 Wiping section 62 Wiping material moving mechanism 63 Holding part 64 Gear operation unit 73 Wipe holder 73a Rotation axis 73J Axis 74 Wiping materials 74M wiping surface 75 gears 76 Torque limiter 83 Gear contact member 90 Contact part change mechanism PST Paste KB board

Claims

1. A screen printing apparatus that prints a paste on a substrate using a mask having predetermined openings, a print head that fills the openings of the mask with paste when the substrate comes into contact with the paste and prints the paste on the substrate; a mask cleaning means for scraping off paste adhered to the rear surface of the mask by a blade due to filling of the paste by the print head; and a blade cleaning means for wiping off the paste scraped off by the blade. The blade cleaning means is a wiping material contacting the blade; a wiping material moving mechanism that moves the wiping material in a direction along the blade to wipe off the paste scraped off by the blade; a contact portion changing mechanism that changes a portion of the wiping material that comes into contact with the blade by rotating the wiping material around an axis that obliquely intersects with a direction perpendicular to the extending direction of the blade; A screen printing apparatus comprising:

2. 2. The screen printing apparatus according to claim 1, wherein the contact portion changing mechanism includes a wiping material holder having a rotation axis that rotates around the axis and that holds the wiping material, and the wiping material has a three-dimensional shape with a circumferential surface centered on the axis.

3. 3. The screen printing device of claim 2, wherein the contact portion changing mechanism includes a gear provided on the wipe holder and a gear contact member arranged at a position within the movement range of the wipe holder where the gear can come into contact with the gear, and when the wipe moving mechanism moves the wipe holder so that the gear comes into contact with the gear contact member, the wipe holder rotates around the axis.

4. 4. The screen printing device according to claim 3, further comprising a torque limiter that limits the torque transmitted by the rotating shaft, wherein the torque limiter prevents the rotating shaft from rotating when the wiping material is moved along the blade by the wiping material moving mechanism, and allows the rotating shaft to rotate when the wiping material moving mechanism moves the wiping material holder to bring the gear into contact with the gear contact member.

5. 5. The screen printing apparatus according to claim 1, wherein the wiping material is a porous material.

Images