Screen printing device

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 printing head 18 that prints paste Pst on a substrate KB by filling the paste Pst into an opening 13k of a mask 13 contacted with the substrate KB; a mask cleaning unit 21 that makes a blade 42 scrape away the paste Pst made to adhere to a back side of the mask 13 when the paste Pst is charged thereinto by the printing head 18; a blade cleaning unit 23 that wipes out the paste Pst scraped away by the blade 42; and a blade cleaning unit holding part 24 that holds the blade cleaning unit 23 attachably and detachably.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 having a predetermined opening formed therein.

Background Art

[0002] Conventionally, a screen printing apparatus that prints paste on a substrate using a mask having a predetermined opening formed therein is known. In such a screen printing apparatus, after filling the opening of the mask with paste by a squeegee, an operation of separating the substrate from the mask (so-called plate separation) is performed. However, since paste flowing from inside the opening adheres to the lower surface of the mask after this plate separation, if the next printing operation is performed as it is, the paste may adhere to the upper surface of a new substrate and cause defective substrate production.

[0003] For this reason, Patent Document 1 below discloses a screen printing apparatus provided with a cleaning device for removing the paste adhering to the lower surface of the mask. This cleaning device includes a plurality of scraping members that scrape off the paste adhering to the lower surface of the mask by sliding the lower surface of the mask in a cleaning direction along the mask, and a holding body that holds these plurality of scraping members. The plurality of scraping members are held by the holding body in series with respect to the cleaning direction.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the scraping tool used to clean the mask had paste scraped off from the mask attached to it, and if the cleaning process for the next mask was performed without removing the scraping tool, there was a risk that the paste attached to the scraping tool would instead adhere to the mask.

[0006] Therefore, the present invention aims to provide a screen printing apparatus that can prevent paste scraped off during the mask cleaning process from adhering to the mask during the next cleaning process. [Means for solving the problem]

[0007] The screen printing apparatus of the present invention is a screen printing apparatus that prints paste onto a substrate using a mask having predetermined openings, comprising: a printing head that fills the openings of the mask in contact with the substrate with paste to print paste onto the substrate; a mask cleaning means that scrapes off paste adhering to the back surface of the mask due to paste filling by the printing head with a blade; a blade cleaning means that wipes off the paste scraped off by the blade; and a blade cleaning means holding part that holds the blade cleaning means in a detachable state. 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 away the paste scraped by the blade, and a pair of held parts that are positioned at separate locations in a direction along the blade and are held by the blade cleaning means holding part. . [Effects of the Invention]

[0008] According to the present invention, it is possible to prevent the paste scraped off during the mask cleaning process from adhering to the mask during the next cleaning process. [Brief explanation of the drawing]

[0009] [Figure 1] Plan view of a screen printing apparatus according to one embodiment of the present invention. [Figure 2] Side view of the main part of a screen printing apparatus in one embodiment of the present invention. [Figure 3] Plan view of the mask holding section and blade cleaning unit of a screen printing apparatus according to one embodiment of the present invention. [Figure 4]Plan view of the mask holding section and blade cleaning unit of a screen printing apparatus according to one embodiment of the present invention. [Figure 5] (a)(b) Operational diagram of a screen printing apparatus in one embodiment of the present invention [Figure 6] (a)(b) Operational diagram of a screen printing apparatus in one embodiment of the present invention [Figure 7] Perspective view of a mask cleaning unit included in a screen printing apparatus according to one embodiment of the present invention. [Figure 8] Side view of a mask cleaning unit included in a screen printing apparatus according to one embodiment of the present invention. [Figure 9] Operational diagram of a screen printing apparatus in one embodiment of the present invention. [Figure 10] (a)(b) Diagram illustrating the operation of the mask cleaning unit included in a screen printing apparatus according to one embodiment of the present invention. [Figure 11] Cross-sectional view of a mask cleaning unit included in a screen printing apparatus according to one embodiment of the present invention. [Figure 12] A perspective view showing a part of the blade cleaning unit and a part of the blade cleaning unit holder in a screen printing apparatus according to one embodiment of the present invention. [Figure 13] A perspective view showing a part of the blade cleaning unit and a part of the blade cleaning unit holder in a screen printing apparatus according to one embodiment of the present invention. [Figure 14] A plan view showing a part of the blade cleaning unit and a part of the mask cleaning unit in a screen printing apparatus according to one embodiment of the present invention. [Figure 15] A partial side view of a blade cleaning unit included in a screen printing apparatus according to one embodiment of the present invention. [Figure 16] Partial cross-sectional side view of a contact portion changing mechanism in a screen printing apparatus according to one embodiment of the present invention. [Figure 17] (a)(b) Diagram illustrating the operation of the contact portion changing mechanism of a screen printing apparatus according to one embodiment of the present invention. [Figure 18](a)(b)(c) Operational explanatory diagram of the contact part changing mechanism included in the screen printing apparatus in one embodiment of the present invention [Figure 19] Partial side view (a) and plan view (b) showing a part of the squeegee cleaning unit included in the screen printing apparatus in one embodiment of the present invention together with a part of the blade of the mask cleaning unit [Figure 20] (a)(b)(c) Schematic explanatory diagram showing an example of the paste trace formed on the wiping surface of the wiping material included in the screen printing apparatus in one embodiment of the present invention [Figure 21] Process diagram of the screen printing method by the screen printing apparatus in one embodiment of the present invention [Figure 22] Diagram showing a state where the screen printing apparatus in one embodiment of the present invention is imaging the state near the opening of the mask by a camera after performing plate separation [Figure 23] Diagram showing an example of an image obtained by imaging the state near the opening of the mask by a camera after the screen printing apparatus in one embodiment of the present invention performs plate separation [Figure 24] Plan view showing a part of the blade cleaning unit included in the screen printing apparatus in the first modification of one embodiment of the present invention together with a part of the mask cleaning unit [Figure 25] Plan view of the mask holding part and the blade cleaning unit holding part included in the screen printing apparatus in the second modification of one embodiment of the present invention

Embodiments for Carrying Out the Invention

[0010] Embodiments of the present invention will be described below with reference to the drawings. Figures 1 and 2 show a screen printing apparatus 1 in 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 produces mounted circuit boards by mounting components onto a substrate KB. The screen printing apparatus 1 repeatedly performs a series of operations (screen printing operation) consisting of loading a substrate KB sent from outside the screen printing apparatus 1, positioning it, printing a paste Pst such as solder onto an electrode DK (Figure 2) provided on the upper surface of the substrate KB, and then unloading it to the outside.

[0011] In this embodiment, for the sake of explanation, the transport (in and out) direction of the substrate KB is defined as the X direction (left-right direction as seen from the operator OP), the horizontal direction perpendicular to the X direction is defined as the Y direction (front-back direction as seen from the operator OP), and the up-down direction is defined as the Z direction. Furthermore, within the Y direction (front-back direction), the direction towards the back as seen from the operator OP (upper side of the paper in Figure 1) is defined as the front, and the direction towards the front as seen from the operator OP (lower side of the paper in Figure 1) is defined as the rear.

[0012] In Figures 1 and 2, the screen printing apparatus 1 comprises a substrate transport unit 11, a substrate holding unit 12, a mask 13, a mask holding unit 14, a camera 15, a camera moving mechanism 16, a substrate holding unit moving mechanism 17, a print head 18, and a print head moving mechanism 19. The screen printing apparatus 1 also further comprises a mask cleaning unit 21, a mask cleaning unit moving 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, separated on both sides in the X direction when viewed from the substrate holding unit 12. The upstream transport unit 11A and the downstream transport unit 11B are composed of a pair of conveyors C arranged side by side in the Y direction and each extending in the X direction, and the conveyors C are driven to transport the substrate KB in the X direction. The substrate transport unit 11 performs the operation of transporting the substrate KB (substrate KB on which paste Pst will be printed) into the substrate holding unit 12 before paste Pst is printed on it, and the operation of transporting the substrate KB with the paste Pst printed on it from the substrate holding unit 12.

[0014] The substrate holding unit 12 has the function of holding the substrate KB that has been transported by the substrate transport unit 11. The substrate holding unit 12 holds the substrate KB in a horizontal position with the electrodes DK facing upward (Figure 2). The substrate holding unit 12 also has a substrate moving mechanism (not shown) that moves the substrate KB in the X direction. This substrate moving mechanism moves the substrate KB that has been transported from the upstream transport unit 11A to the holding position, and then discharges the substrate KB from the holding position to the downstream transport unit 11B.

[0015] In Figure 1, the mask 13 is made of a rectangular metal plate-like member. The four sides of the mask 13 are supported by a mask frame 13W, which is made of a rectangular frame. Multiple openings 13K are formed in the center of the mask 13, arranged according to the arrangement of electrodes DK on the substrate KB.

[0016] In Figures 1, 3, and 4, the mask holding section 14 comprises two mask support guides 31 arranged side by side in the X direction and each extending in the Y direction, and four mask fixing sections 32 installed on the two mask support guides 31. As shown in Figure 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] In Figure 1, the four mask fixing parts 32 are arranged in a line in the Y direction, two on each of the two mask support guides 31. Each mask fixing part 32 is configured to fix a portion of the mask frame 13W to the mask support guide 31 by pressing it from above with a cylinder (not shown), for example. 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] In Figure 2, the camera 15 is positioned at a height between the substrate KB, which is held by the substrate holder 12, and the mask 13. The camera 15 is capable of acquiring images from both above and below simultaneously or by switching between them. The images of the mask mark and the substrate mark captured by the camera 15 are processed by a control unit (not shown) of the screen printing apparatus 1, and the relative position between the mask 13 and the substrate KB is calculated.

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

[0020] The camera movement mechanism 16 moves the camera 15 in the horizontal plane (XY plane) in the region below the mask 13 by moving the X guide 16b in the Y direction relative to the Y guide 16a (arrow A shown in Figure 2) and moving the camera 15 in the X direction relative to the X guide 16b. As a result, the camera 15 moves horizontally into the space between the substrate KB and the mask 13, making it possible to image both a mark (not shown) on the mask 13 (mask-side mark) and a mark (not shown) on the substrate KB (substrate-side mark) (Figure 5(a)).

[0021] In Figure 2, the substrate holder movement mechanism 17 moves the substrate holder 12, which holds the substrate KB, in the X, Y, Z directions and the rotational direction (θ direction) within the XY plane. Based on the relative position between the mask 13 and the substrate KB determined by the control unit, the substrate holder movement mechanism 17 moves the substrate holder 12 in the X, Y, and θ directions, and raises the substrate holder 12 while aligning the substrate KB with the mask 13. As a result, the substrate holder 12 raises the substrate KB and brings it into contact with the lower surface of the mask 13 (Figure 5(b)).

[0022] In Figures 1 and 2, the print head 18 comprises a head base 18a extending in the X direction and two squeegees 18b. The squeegee 18b consists of a plate-shaped member extending in the X direction. The two squeegees 18b are positioned opposite each other in the Y direction and are spaced further apart downwards (Figure 2). The two squeegees 18b can be raised and lowered independently of the head base 18a.

[0023] In Figure 2, the print head moving mechanism 19 moves the print head 18 in the Y direction, with the lower end of one squeegee 18b in contact with the upper surface of the mask 13 (Figure 5(b) → Figure 6(a)). As a result, the print head 18 uses the squeegee 18b to scrape the paste Pst on the mask 13, filling the opening 13K of the mask 13 with the paste Pst, and printing (applying) the paste Pst to the electrode DK of the substrate KB.

[0024] Once the opening 13K of the mask 13 is filled with paste Pst, the substrate holding mechanism 17 lowers the substrate holding part 12 to separate the substrate KB from the mask 13 (arrow B shown in Figure 6(b)). Once the substrate KB has separated from the mask 13, the substrate transport part 11 discharges 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 for holding the substrate KB that has been brought in, a substrate holding unit moving mechanism 17 for moving the substrate holding unit 12, a print head 18 for filling the opening 13K of the mask 13 in contact with the substrate KB with paste Pst and printing the paste Pst onto the substrate KB, and a substrate transport unit 11 for receiving the substrate KB that will have paste printed on it, and for transporting the substrate KB that has been separated from the mask 13 by the substrate holding unit moving mechanism 17 after the paste Pst has been printed by the print head 18.

[0026] The mask cleaning unit 21 functions as a mask cleaning means for scraping off paste Pst adhering to the lower surface of the mask 13 after the stencil has been removed. As shown in Figure 7, the mask cleaning unit 21 comprises a blade holder 41 and a plurality (in this case, four) of blades 42 held by the blade holder 41. The blade holder 41 comprises a frame 41a that extends in the X direction 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 consist of plate-shaped members that extend in the X direction and are held within the frame 41a in a state where they are arranged parallel to the Y direction. In this embodiment, the blades 42 are made of resin and are members with appropriate flexibility.

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

[0028] The mask cleaning unit movement mechanism 22 functions as a mask cleaning means movement unit that moves the mask cleaning unit 21 horizontally (Y direction) along the lower surface of the mask 13. As shown in Figure 1, it comprises a movement guide 22a extending in the Y direction from the outside of the mask holding part 14 in the X direction, and a movement base 22b extending in the X direction. The movement base 22b is supported by the movement guide 22a and is freely movable in the Y direction.

[0029] A mask cleaning unit 21 (specifically, the frame 41a of the blade holder 41) is attached to the top of the mobile base 22b. The mobile 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 out by a suction device 22S (Figure 2) connected to the mobile base 22b.

[0030] The mobile base 22b (i.e., the mask cleaning unit 21) has a standby position on the outside in the Y direction (specifically, the rear, towards the operator OP) of the mask holding section 14. When performing a cleaning operation (mask cleaning operation) to scrape off paste Pst adhering to the lower surface of the mask 13 using the mask cleaning unit 21, the mask cleaning unit movement mechanism 22 moves the mask cleaning unit 21 from the standby position forward, then reverses its orientation and moves the mask cleaning unit 21 backward (arrow C shown in Figure 9).

[0031] When the mask cleaning unit 21 is moved backward (Figure 10(a) → Figure 10(b)), the mask cleaning unit 21 brings the edges 42E of each of the four blades 42 into contact with the lower surface of the mask 13, and the upper surfaces (mask contact surfaces 41T) of each of the pair of mask receiving parts 41b into contact with the lower surface of the mask 13. As a result, when the mask cleaning unit 21 is moved backward by the mask cleaning unit moving mechanism 22, the four blades 42 slide along the lower surface of the mask 13, scraping off the paste Pst adhering to the lower surface of the mask 13 with their edges 42E. While each blade 42 is in contact with the lower surface of the mask 13, it deforms to elastically bend in the opposite direction to the direction of movement (forward in this case), thereby maintaining the state in which the edge 42E is in close contact with the lower surface of the mask 13 (Figure 10(a) → Figure 10(b)).

[0032] As described above, while the blade 42 is in contact with the lower surface of the mask 13, 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 progression of wear of the blade 42 within the expected range.

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

[0034] As described above, the mask cleaning unit 21 of this embodiment is configured to scrape off the paste Pst adhering to the lower surface of the mask 13 by moving the lower part of the mask 13 in a horizontal direction (Y-axis direction) parallel to the mask 13 while the upper edge (edge ​​42E) of the blade 42 is in contact with the lower surface of the mask 13.

[0035] Once the mask cleaning operation by the mask cleaning unit 21 is complete, the mask cleaning unit movement mechanism 22 returns the mask cleaning unit 21 to its standby position. In its 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] Figure 11 shows the mask cleaning unit 21 after the mask cleaning operation is completed, with the edges 42E of the blades 42 separated from the lower surface of the mask 13. Each blade 42 returns to its original shape, which is not elastically deformed when separated from the mask 13. The edges 42E of each blade 42 are 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 scraped from the underside of the mask 13 by the blade 42 of the mask cleaning unit 21 during the mask cleaning operation. For this reason, as shown in Figures 3 and 4, the blade cleaning unit 23 is located in a position corresponding to the standby position of the mask cleaning unit 21, that is, outside the mask 13 in a plan view (behind the area in the mask holding part 14 where the mask 13 is installed).

[0038] The blade cleaning unit holder 24 functions as a blade cleaning means holder that holds the blade cleaning unit 23 in a position corresponding to the standby position of the mask cleaning unit 21 (a position outside the mask 13 in a plan view). For this reason, as shown in Figures 3 and 4, the blade cleaning unit holder 24 is provided in the outer region of the mask 13 (more specifically, the rear region of the area in the mask holder 14 where the mask 13 is installed) of the pair of mask support guides 31 that constitute the mask holder 14.

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

[0040] In Figures 3 and 4, the pair of positioning parts 52 are provided on the rear sides of each end of the partition part 51. As shown in Figure 12, each pair of positioning parts 52 consists of a block-shaped member, and an engagement hole 52H is provided on the rear contact surface 52M.

[0041] In Figures 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 is formed on the upper surface of each support portion 53, having a sloping portion that rises gently from rear to front. In this embodiment, the guide portion 54 is made up of a part of the mask support guide 31, and the guide surface 54M, which is the inner surface (the side on which the pair of guide portions 54 face each other), is formed parallel to the YZ plane.

[0042] As can be seen from Figures 3, 4, and 12, the pair of support parts 53 consist of a part (the part behind the partition part 51) of the pair of mask support guides 31 that constitute the mask holding part 14. In other words, in this embodiment, the blade cleaning unit holding part 24 is provided as an integral part of the mask holding part 14. Therefore, the 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] In Figures 3, 4, and 14, the blade cleaning unit 23 comprises a wiping section 61, a wiping material moving mechanism 62, a pair of holding sections 63, and a gear operating section 64. As shown in Figures 14 and 15, the wiping section 61 comprises 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] In Figures 14 and 15, the base portion 71 consists of a horizontally extending plate-shaped member, and the holding portion 72 consists of a block-shaped member. The holding portion 72 is positioned relative to the base portion 71 by contacting from the side with a plurality of positioning pins 71P (Figure 14) erected on the upper surface of the base portion 71, and in that state is fixed onto the base portion 71 by bolts 71B screwed into the base portion 71 from above.

[0045] In Figures 14 and 15, the wiping material holder 73 has a rotating shaft 73a, one end (rear end) of which is held by a holding part 72, a disc-shaped base 73b provided on the other end (front end) of the rotating shaft 73a, and a plurality of 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 (X direction) in which the blade 42 of the mask cleaning unit 21 extends (Figure 14). The wiping material 74 is made of, for example, a porous material and has a three-dimensional shape (cylindrical shape) with a circumferential surface (see Figure 7).

[0046] The wiping material 74 is detachably held in the wiping material holder 73 by being inserted through a plurality of holding rods 73c. ​​The gear 75 is fixed to the rotating shaft 73a and rotates together with the rotating shaft 73a around the axis 73J of the rotating shaft 73a. As shown in Figure 16 (Figure 16 is a view from the line V1-V1 shown in Figure 14), the gear 75 has a large number of teeth (outer teeth 75T) on its outer circumference, and these outer teeth 75T are inclined with respect to the axis 73J of the rotating shaft 73a. In other words, in this embodiment, the gear 75 is a helical gear, and the orientation of its outer teeth 75T (the peaks extending in the width direction) extends almost parallel to the YZ plane (Figure 14).

[0047] In Figures 14 and 15, the torque limiter 76 is located within the holding section 72 and limits the torque transmitted by the rotating shaft 73a. Specifically, the torque limiter 76 ensures that if the torque acting on the rotating shaft 73a from the wiping material 74 or the gear 75 is less than or equal to a predetermined limit value (torque limit value), that torque is transmitted to the holding section 72 (rotation of the rotating shaft 73a is prevented). If the torque acting on the rotating shaft 73a from the gear 75 exceeds the torque limit value, that torque is not transmitted to the holding section 72 (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 (or more directly, the base portion 71) in the X direction (arrow E shown in Figure 7). As a result, the wiping material 74 moves between an initial position set at one end of the blade 42 of the mask cleaning unit 21 (in this case, the right end) (see wiping material 74 shown by a solid line in Figure 7) and a maximum movement position set at the other end of the blade 42 (in this case, the left end) (see wiping portion 61 shown by a dashed line in Figure 7).

[0049] In Figures 3 and 4, the pair of holding portions 63 are provided extending forward from both ends in the X direction of the wiping material moving mechanism 62. That is, the pair of holding portions 63 are positioned at separate locations in the wiping material movement direction (X direction), which is the direction in which the wiping material 74 moves along the blade 42 of the mask cleaning unit 21.

[0050] In Figure 3, a projection 63T is formed at the front end of each of the pair of retained portions 63, extending inward in the X direction (towards the side where the pair of retained portions 63 face each other). An engagement pin 63P extends forward from the contact surface 63M, which is the front surface of the projection 63T (see also Figures 12 and 14).

[0051] In Figures 3, 4, and 14, the gear operating section 64 is located on one side (in this case, the right-hand holding section 63) of the pair of holding sections 63 provided by the blade cleaning unit 23. As shown in Figure 16, the gear operating section 64 is configured with a spring-loaded hinge 81, a spacer 82, and a gear contact member 83.

[0052] In Figures 14 and 16, one wing portion (fixed wing portion 81a) of the hinge 81 is fixed horizontally to the upper surface of the retained portion 63, while the other wing portion (movable wing portion 81b) is pivotable around the axis of the shaft portion 81c extending in the Y direction. The spacer 82 is attached to the lower surface of the movable wing portion 81b of the hinge 81, and the base end (right end in Figure 16) of the gear contact member 83 is attached to the spacer 82. As a result, the gear contact member 83, together with the spacer 82 and the movable wing portion 81b, pivots (undulates) around the axis of the shaft portion 81c as a fulcrum.

[0053] The spacer 82 limits the range of elevation of the movable vane portion 81b (and therefore the gear contact member 83) so that the gear contact member 83 does not fall over beyond a horizontal position. As a result, when no upward force is acting on the tip portion 83T of the gear contact member 83, the spacer 82 contacts the held portion 63, as shown in Figure 16, so that it is in a horizontal position and is on the same plane as the fixed vane portion 81a. When an upward force is applied to the tip portion 83T of the gear contact member 83 in the horizontal position, the movable vane portion 81b rises and falls around the axis of the shaft portion 81c (in the direction of raising the tip portion 83T), but when the upward force is removed, it returns to its original horizontal position due to the biasing force of the biasing spring.

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

[0055] As shown in Figure 14, when the wiping material 74 is in its 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 (Figure 16), the gear contact member 83 does not receive an upward force from the gear 75. Therefore, when the wiping material 74 is in its initial position, the movable side wing portion 81b of the hinge 81 is on the same plane as the fixed side wing portion 81a.

[0056] Here, as the wiping material 74 moves from its initial position toward its maximum movement position (Figure 17(a) → Figure 17(b)), the outer teeth 75T that were inserted into the opening 83K receive a force from the horizontally positioned gear contact member 83 in a direction that hinders its movement (in this case, to the right). However, at this time, the outer teeth 75T that were inserted into the opening 83K of the gear contact member 83 push up (raise and lower) the tip 83T of the gear contact member 83 and disengage from 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 Figure 17(b)).

[0057] On the other hand, when the wiping material 74 that has moved from the maximum movement position returns to the initial position (Figure 18(a) → Figure 18(b) → Figure 18(c)), in the process of its return, one of the outer peripheral teeth 75T of the gear 75 contacts 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 because of the spacer 82 and supports the horizontal posture. Therefore, a large reaction force G (Figure 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 (that is, the rotating shaft 73a) by the reaction force G (T0 < T1). Therefore, the rotating shaft 73a rotates around the axis 73J together with the gear 75 (the arrow R shown in Figure 18(c)). At this time, the angle of the rotating shaft 73a that rotates is the angle corresponding to one of the outer peripheral teeth 75T of the gear 75, and the wiping material 74 also rotates around the axis 73J of the rotating 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 contact the contact surfaces 52M of each of the pair of positioning portions 52 (Figure 3 → Figure 4 and Figure 12 → Figure 13). Thereby, the blade cleaning unit 23 is positioned in the Y direction with respect to the blade cleaning unit holding portion 24.

[0061] Between the contact surfaces 63M of each of the pair of protrusions 63T and the contact surfaces 52M of each 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, thereby positioning them 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 guide parts 54 (guide surfaces 54M) of the blade cleaning unit holding part 24, thereby positioning them in the X direction.

[0062] The pair of protrusions 63T of the blade cleaning unit 23 contact the inclined surfaces 55M (Figure 12) of each of the pair of hook portions 55 provided on the blade cleaning unit holding portion 24, while their contact surfaces 63M are in contact with the pair of contact surfaces 52M of the blade cleaning unit holding portion 24, and elastically push down the hook portions 55. Then, when the lower surface of the protrusion 63T has finished passing the inclined surface 55M at the time the contact surface 63M contacts the contact surface 52M, the hook portions 55 are released from being pushed down by the protrusions 63T and return to their original position.

[0063] The hook portion 55, having returned to its original position, engages with the back surface 63N of the protruding portion 63T (Figures 3 and 12) (Figure 12 → Figure 13). As a result, the blade cleaning unit 23 is 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 of the blade cleaning unit 23 is positioned above the mask cleaning unit 21, which is in the standby position (Figures 1 and 2).

[0064] As described above, the blade cleaning unit 23 of the screen printing apparatus 1 in this embodiment comprises a wiping material 74 that contacts the blade 42 of 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 away the paste Pst scraped off by the blade 42, and a pair of held parts 63 that are positioned at separate locations 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 perpendicular to the direction along the blade 42 (X direction) (Y direction) to be mounted (held) by the blade cleaning unit holding part. The blade cleaning unit holding part 24 has a pair of support parts 53 that support the lower surfaces of the pair of held parts 63 (specifically a pair of protruding parts 63T) when the blade cleaning unit 23 is mounted, and a pair of guide parts 54 that guide the sides of each of the held parts 63 as they move on the support parts 53.

[0065] To remove the blade cleaning unit 23 while it is held in the blade cleaning unit holder 24, simply push down the pair of hooks 55 and pull the blade cleaning unit 23 backward. In this way, the screen printing apparatus 1 in this embodiment makes it easy to attach and detach the blade cleaning unit 23 from the blade cleaning unit holder 24.

[0066] As described above, the screen printing apparatus 1 in this embodiment is equipped with a blade cleaning unit holder 24 that detachably holds the blade cleaning unit 23, which wipes off the paste Pst scraped off by the blade 42. The blade cleaning unit 23 can be easily removed from the blade cleaning unit holder 24, so the blade cleaning unit 23 does not get in the way during maintenance or inspection of the screen printing apparatus 1. In addition, 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 holder 24.

[0067] When the blade cleaning unit 23 performs the 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 material moving mechanism 62 moves the wiping section 61, which is initially in position, toward its maximum movement position. As a result, the wiping material 74 moves in the X direction, that is, in the direction in which each blade 42 extends, while in contact with the edges 42E of each of the four blades 42, sliding along the edges 42E and wiping off the paste Pst scraped from the lower surface of the mask 13 by each blade 42.

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

[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) that acts on the rotating shaft 73a when the wiping surface 74M of the wiping material 74 receives resistance from the blade 42 during blade cleaning (when the wiping material 74 is moved) (T2 <T0)。

[0070] Thus, in this embodiment, a torque limiter 76 is provided to limit the torque transmitted by the rotating shaft 73a. 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 by the torque limiter 76, 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 and return paths.

[0072] Thus, in the screen printing apparatus 1 according to this embodiment, since the paste Pst adhering 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. [[ID=IO]]

[0073] In this embodiment, the gear 75 constituting the wiping section 61 is not rotated by the gear contact member 83 during the forward movement, when the wiping material 74 is moved from the initial position to the maximum movement position by the wiping material moving mechanism 62 (Figure 17(a) → Figure 17(b)). During the return movement, when the gear 75 is moved from the maximum movement position to the initial position, it is rotated by the reaction force G received from the gear contact member 83 when the outer circumferential teeth 75T of the gear 75 come into contact with the gear contact member 83 (Figure 18(a) → Figure 18(b) → Figure 18(c)). At this time, the gear 75 rotates by the amount of one outer circumferential tooth 75T, so the wiping surface 74M of the wiping material 74 moves on the circumferential surface of the wiping material 74 by a distance L corresponding to one outer circumferential tooth 75T, and the wiping surface 74M of the wiping material 74 is changed.

[0074] As described above, the blade cleaning unit 23 of the screen printing apparatus 1 in this embodiment has a configuration comprising a wiping material holder 73 that holds a cylindrical (three-dimensional shape with a circumferential surface) wiping material 74 and has a rotating shaft 73a that rotates about an axis 73J, a gear 75 provided on the wiping material holder 73, and a gear contact member 83 positioned to contact the gear 75 within the range of movement of the wiping material holder 73 (here, the range between the initial position and the maximum movement position). 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 and changes the wiping surface 74M.

[0075] In this embodiment, the portion of the wiping material 74 that contacts the blade 42 (wiping surface 74M) can be changed by a simple operation of rotating the wiping material holder 73 around the axis 73J, thereby simplifying the configuration. Furthermore, since a dedicated power source (such as a motor or cylinder) is not required solely 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 form a contact portion changing mechanism 90 that changes the portion of the wiping material 74 that contacts the blade 42 (wiping surface 74M) by rotating the wiping material 74 about an axis 73J that intersects diagonally with the direction perpendicular to the direction (Y direction) of extension of the blade 42 (X direction).

[0077] Figures 20(a), (b), and (c) schematically show the state of the paste Pst marks formed on the wiping surface 74M of the wiping material 74 when the gear 75 is rotated by the gear contact member 83 by the width of one outer tooth 75T. Figure 20(b) shows the state in which the wiping surface 74M has moved by a distance L corresponding to one outer tooth 75T from the state in Figure 20(a), and Figure 20(c) shows the state in which the wiping surface 74M has moved by a distance 5L (L × 5) corresponding to five outer teeth 75T from the state in Figure 20(a).

[0078] As can be seen from Figures 20(a), (b), and (c), the direction in which the traces of paste Pst extend on the wiping surface 74M is inclined with respect to the direction perpendicular to the projection line TS obtained by projecting the axis 73J of the rotation axis 73a onto the circumferential surface of the wiping material 74. Therefore, even if a wiping surface 74M and a wiping surface 74M moved by a distance L equivalent to one outer tooth 75T overlap in a part (end), the traces of paste Pst on the wiping surface 74M and the paste Pst on the wiping surface 74M moved by a distance L do not overlap in their end region TR (Figures 20(b), (c)).

[0079] This effect is achieved because the wiping material 74 has a three-dimensional shape (cylindrical shape) with a circumferential surface centered on its axis 73J, and by rotating it around its axis 73J, the wiping surface 74M with respect to the blade 42 can be changed. In addition, the axis 73J of the rotation axis 73a is tilted horizontally from the direction perpendicular to the direction in which the blade 42 extends (X direction) (Y direction).

[0080] Next, the flow of the screen printing operation (screen printing method) performed by the screen printing apparatus 1 will be explained. As shown in Figure 21, the screen printing method by the screen printing apparatus 1 involves the following steps in this order: substrate loading, contact, printing, screen release, and substrate unloading. In parallel with these steps, the mask cleaning and blade cleaning processes are also performed in this order.

[0081] The substrate loading process is a process in which substrates KB, which will be printed with paste Pst, are loaded into the screen printing apparatus 1. This process is performed by the substrate transport unit 11 transporting (loading) the substrates KB supplied from outside the screen printing apparatus 1. The contact process is a process in which the substrates KB loaded in the substrate loading process are aligned with the mask 13 and brought into contact with the lower surface of the mask 13. This process is performed by the substrate holding unit moving mechanism 17 bringing the substrates KB into contact with the lower surface of the mask 13.

[0082] The printing process involves filling the opening 13K of the mask 13, which has been in contact with the substrate KB in the contact process, with paste Pst and printing the paste Pst onto the substrate KB. This is performed by filling the opening 13K of the mask 13, which has been in contact with the substrate KB, with paste Pst using the print head 18. The stencil release process is performed after the printing process to separate the substrate KB from the mask 13. This is performed by separating the substrate KB, which has the paste Pst printed on it, from the mask 13 using the substrate holding mechanism 17. The substrate removal process is performed after the printing process to remove the substrate KB. This is performed 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 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 performed by the mask cleaning unit 21 being moved on the underside of the mask 13 by the mask cleaning unit moving mechanism 22. The blade cleaning process is a process in which the blade cleaning unit 23 cleans the blade 42 that scraped off the paste Pst from the underside of the mask 13 during the mask cleaning process, and is performed by the blade cleaning unit 23 moving the wiping material 74 in the direction in which the blade 42 extends by the wiping material moving mechanism 62.

[0084] In this embodiment, the screen printing method comprises a substrate loading process, a printing process, a substrate unloading process, a mask cleaning process, and a blade cleaning process. The substrate loading process, the printing process, and the substrate unloading process are performed in this order for each substrate KB that is the target of paste Pst printing. The mask cleaning process is performed by bringing the blade 42 into contact with the mask 13, so it cannot be performed during the printing process (nor during the blade cleaning process). Therefore, if the mask cleaning operation is performed after each paste Pst printing is completed for one substrate KB, the mask cleaning operation should be performed between the completion of the stencil separation process and the start of the next contact process (from the start of substrate KB unloading until the completion of loading the next substrate KB), as shown in Figure 21.

[0085] Furthermore, since the blade cleaning operation is a process of cleaning the blade 42 of the mask cleaning unit 21 that scraped the paste Pst from the underside of the mask 13 during the mask cleaning process, it cannot be performed while the mask cleaning operation is in progress and must be started after the mask cleaning operation is completed. The blade cleaning operation can be performed except while the mask cleaning operation is in progress, but if the mask cleaning operation and blade cleaning operation (fixing) are performed each time the paste Pst is printed on a single substrate KB, then, as shown in Figure 21, the blade cleaning operation should be completed between the end of the mask cleaning operation and the end of the next plate separation operation.

[0086] In this way, if the mask cleaning process is performed between the completion of the stencil separation process and the start of the next contact process, and the blade cleaning process is completed between the completion of the mask cleaning process and the completion of the next stencil separation process, then it is not only unnecessary to stop the operation of the screen printing apparatus 1 for the mask cleaning process, but also unnecessary to stop the operation of the screen printing apparatus 1 for the blade cleaning process. Therefore, according to the screen printing apparatus 1 (screen printing method) in this embodiment, it is possible to prevent a decrease in the productivity of the screen printing apparatus 1 (and by extension, the component mounting line), while also preventing the paste Pst scraped off during the cleaning of the mask 13 from adhering to the next mask 13.

[0087] In the above explanation, we described a case where mask cleaning is performed after each paste Pst printing is completed for one substrate KB. However, the mask cleaning process does not have to be performed after each substrate KB is printed; it may be performed after several substrates KB are printed. Alternatively, as shown in Figure 22, the lower surface of the mask 13 immediately after stencil separation is imaged by the camera 15, and the adhesion status of the paste Pst in the opening 13K is examined based on the image GZ obtained (Figure 23). Then, as shown in Figure 23, if a smudged area NJ or a clogged area TM is observed in the opening 13K of the mask 13, the mask cleaning may be performed as a trigger, followed by the blade cleaning.

[0088] (First variation) The first modifiable feature in this embodiment is shown. In the first modified example, as shown in Figure 24, the gear 75 in the blade cleaning unit 23 is a spur gear instead of a helical gear. Also, the opening 83K in the gear contact member 83 is trapezoidal in plan view, and the left of the two sides facing each other in the X direction is angled 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 axis 73a, so the same effect as in the above-described embodiment can be obtained.

[0089] (Second variation) Next, a second modification of this embodiment is shown. In the second modification, as shown in Figure 25, the blade cleaning unit holding portion 24 is a separate component from the mask holding portion 14. That is, in the second modification, 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 independent components of the pair of mask support guides. This configuration, in which the blade cleaning unit holding portion 24 is a separate component from the mask holding portion 14, is extremely useful when the distance between the pair of mask support guides 31 in the Y direction can be changed to match the size of the substrate KB (see arrow H shown in Figure 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 paste Pst adhering to the blade 42 of the mask cleaning unit 21. This prevents the paste Pst scraped off by the mask cleaning unit 21 during the mask cleaning operation from adhering to the mask 13 during the next cleaning operation.

[0091] Furthermore, the screen printing apparatus 1 in this embodiment is equipped with a blade cleaning unit holder 24 that detachably holds the blade cleaning unit 23, which wipes off the paste Pst scraped off by the blade 42. Since the blade cleaning unit 23 can be easily removed from the blade cleaning unit holder 24, the blade cleaning unit 23 does not get in the way during maintenance or inspection of the screen printing apparatus 1. In addition, 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 holder 24.

[0092] While embodiments of the present invention have been described above, the present invention is not limited to those described above, and various modifications are possible. For example, in the above-described embodiment, the wiping material 74 had a three-dimensional shape (cylindrical shape) with a circumferential surface, but this is just one example, and the shape of the wiping material 74 is not limited. [Industrial applicability]

[0093] The present invention provides a screen printing device that can prevent the paste scraped off during the mask cleaning process from adhering to the mask during the next cleaning process. [Explanation of symbols]

[0094] 1. Screen printing device 13 masks 13K aperture 18 Printheads 21 Mask cleaning unit (mask cleaning means) 23. Blade cleaning unit (blade cleaning means) 24 Blade cleaning unit holding section (blade cleaning means holding section) 42 blades 53 Support part 54 Information Department 61 Wiping section 62. Wiping material transfer mechanism 63 Holding part 74 Wiping agent Pst Paste KB substrate

Claims

1. A screen printing apparatus for printing paste onto a substrate using a mask in which predetermined openings are formed, A print head that fills the opening of the mask in contact with the substrate with paste and prints the paste onto the substrate, A mask cleaning means that scrapes off the paste adhering to the back surface of the mask by a blade due to paste filling by the print head, A blade cleaning means for wiping off the paste scraped off by the blade, A blade cleaning means holding unit that holds the blade cleaning means in a detachable state, Equipped with, 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 away the paste scraped off by the blade, and a pair of held parts that are positioned at separate locations in a direction along the blade and held by the blade cleaning means holding part.

2. The screen printing apparatus according to claim 1, wherein the blade cleaning means is moved in a direction perpendicular to the direction along the blade and mounted on the blade cleaning means holding portion, and the blade cleaning means holding portion comprises a pair of support portions that support the lower surfaces of the pair of held portions when the blade cleaning means is mounted, and a pair of guide portions that guide the sides of each of the held portions as they move on the support portions.

3. The screen printing apparatus according to claim 2, wherein the blade cleaning means holding portion is located in the outer region of the mask in a plan view.

4. The screen printing apparatus according to claim 3, wherein the blade cleaning means holding portion is provided integrally with the mask holding portion that holds the mask.

Images